Dementia

Dementia. FDG-PET/CT Brain FDG-PET is an established tool for differentiating FTD and AD and classifying different FTD subtypes. FDG-PET has a sensitivity of 60% and a positive predictive value of 78.5% for differentiating the subtypes of FTD [44]. The CMS coverage decision for payment for FDG-PET brain, in 2004, was based on FDG brain PET being a very valuable diagnostic study to differentiate AD and FTD in patients with documented cognitive decline of at least 6 months and a recently established diagnosis of dementia [45].


Dementia

Dementia. MR Spectroscopy Head MR spectroscopy metabolite changes in FTD are similar to the changes encountered in AD: lower NAA to creatine (Cr) ratio (NAA/Cr) and higher mI to Cr ratio (mI/Cr) than normal, but findings are more commonly centered on the frontal cortex in early FTD [46]. MR spectroscopy could be a helpful secondary test in patients who have clinical findings of FTD, but it is not a first-line imaging test.


Dementia

Dementia. MRI Functional (fMRI) Head Brain activation has been shown to be significantly decreased in FTD in the frontal and parietal lobes compared with AD [47]. Resting state fMRI demonstrates alterations in structural and functional connectivity in presymptomatic FTD [48]. However, fMRI remains in the realm of research and is not recommended in routine evaluation of FTD.


Dementia

Dementia. MRI Head MRI of the brain without IV contrast serves as a first-line imaging test to exclude secondary causes of symptoms such as subdural hematoma and tumor in patients with suspected FTD. IV contrast is not necessary for initial evaluation. Volumetric MRI has a second-level role in diagnosis and has been actively studied as a tool to assess brain atrophy patterns associated with different FTD clinical phenotypes. Studies show that volumetric MRI allows differentiation of atrophy patterns when analyzed at a group level but currently does not allow assessment on an individual patient level [44]. Several other advanced MRI techniques provide additional information about brain microstructure, and their role in diagnosis of FTD is being investigated [44]. Zhang et al [49] demonstrated that diffusion tensor imaging has significantly greater accuracy for classifying subtypes of FTD than volumetric brain MRI. The role of arterial spin labeling MRI in FTD is currently being studied. The patterns detected using arterial spin labeling MRI has been shown to be similar to FDG-PET findings, and this technique potentially could represent a future alternative to FDG-PET [44].


Dementia

Dementia. HMPAO SPECT or SPECT/CT Brain Tc-99m HMPAO SPECT has been found to be useful in distinguishing FTD from AD and VaD with a pattern of bilateral anterior hypoperfusion. Tc-99m HMPAO SPECT may be used as an adjunct to clinical evaluation and CT but it is not a first-line test [50].


Dementia

Dementia. Variant 3: Suspected dementia with Lewy bodies. Initial imaging. Dementia with Lewy bodies (DLB) has been recognized as the second most prevalent neurodegenerative dementia in the elderly, causing up to 15% of cases [51]. It is a synucleinopathy with accumulation of insoluble alpha- Synuclein that aggregates to form Lewy bodies, which are the major pathological feature of the disease.


Dementia

Dementia. To increase the accuracy of diagnosis of DLB, the latest diagnostic criteria incorporate findings from neuroimaging such as CT, MRI, SPECT, and PET [52]. Some authors have suggested a multimodality approach combining MRI and SPECT modalities as a useful and practical approach for differentiating DLB from AD [51].


Dementia

Dementia. CT Head Noncontrast CT head is a good first-line examination to exclude mimics like brain tumor or subdural hematoma. Relative preservation of the medial temporal lobe structures is also a supportive imaging biomarker according to the fourth consensus report of the DLB consortium [52]. CT with IV contrast or dual-phase CT imaging is not needed for initial evaluation.


Dementia

Dementia. Dementia Amyloid PET/CT Brain DLB is also accompanied by amyloid deposition like AD, but overall, there is decreased uptake compared when with AD patients on amyloid imaging. Compared to Parkinson disease, DLB patients show a higher level of amyloid deposition [53]. At this time, amyloid PET/CT has very limited usefulness for diagnosis of DLB.


Dementia

Dementia. Ioflupane SPECT or SPECT/CT Brain In the present guidelines, decreased dopamine transporter uptake is of the greatest importance among various neuroimaging findings and is listed as one of the suggestive features. Functional imaging of the dopamine transporter (I-123 Ioflupane) using SPECT might identify a defect in the nigrostriatal pathway that occurs in a variety of disorders including DLB and Parkinson disease. I-123 Ioflupane striatal activity tends to be normal in AD and low in DLB and Parkinson disease; however, AD and DLB can coexist in the same patient, potentially confounding results [11,51]. This is not a first-line imaging test but may be valuable after cross-sectional imaging to exclude other pathology.


Dementia

Dementia. MR Spectroscopy Head There is sparse MR spectroscopy data on DLB. In one study [55], DLB patients were characterized by decreased NAA/Cr in the occipital voxel. AD patients were characterized by lower NAA/Cr in the frontal and posterior cingulate voxels. Normal NAA/Cr levels in the frontal voxel differentiated DLB patients with preserved hippocampal volumes from AD patients. MR spectroscopy abnormalities associated with loss of neuronal integrity localized to the occipital lobes in DLB, and the posterior cingulate gyri and frontal lobes in AD. The pattern of MR spectroscopy abnormalities may have a role in differential diagnosis of DLB and in distinguishing DLB patients with overlapping AD pathology. Although in the future, MR spectroscopy can provide additional useful information in the ante-mortem diagnosis of DLB; at present, its usefulness is limited.


Dementia

Dementia. MRI functional (fMRI) Head Studies with fMRI show reduced activation of the occipital-temporal lobe regions during visual tasks. Resting state fMRI has demonstrated increased functional connectivity between the right posterior cingulate gyrus and other regions of the brain and reduced cortico-cortical connectivity. However, the diagnostic utility of fMRI for diagnosis of DLB has not been validated, and thus it cannot be recommended [56].


Dementia

Dementia. MRI Head Routine MRI head is performed to exclude other lesions like tumor or subdural hematoma. Contrast-enhanced MRI is not needed for initial evaluation.


Dementia

Dementia. Volumetric MRI can be done as a secondary test to support the diagnosis. On structural MRI, patients with DLB show less atrophy of the hippocampus and other medial temporal lobe structures compared with AD. For similar levels of dementia severity, DLB appears to have greater subcortical structure atrophy (thalamus, caudate, amygdala, ventral diencephalon, substantia nigra, and midbrain) compared with AD [57]. However, on a single subject level, structural changes are not helpful in differentiating DLB from other dementias. Diffusion tensor imaging studies have described the potential importance of the precuneus in the pathogenesis of DLB as well as AD [35].


Dementia

Dementia. HMPAO SPECT or SPECT/CT Brain The most important finding on brain-perfusion SPECT in DLB is occipital hypoperfusion. This hypoperfusion is listed as a supportive feature in the consensus guidelines [52], and this can be a second-line imaging test to help with the diagnosis. However, this test is less commonly used in clinical practice and has been largely replaced by other imaging modalities.


Dementia

Dementia. Variant 4: Suspected vascular dementia. Initial imaging. Cerebral vascular disease, especially common in the elderly, can lead to VaD [11]. The diagnosis of VaD involves the presence of significant cerebrovascular pathology or risk factors, assessed clinically or using neuroimaging. Recently, the concept of vascular cognitive impairment has been invoked, which refers to the whole spectrum of


Dementia

Dementia. Dementia disorders in which there is cognitive impairment and either clinical evidence of previous stroke or imaging evidence of vascular brain injury, either in isolation (pure vascular disease) or in association with other pathologies (mixed disease) [58]. The three main causes of vascular cognitive impairment are large vessel strokes (macroangiopathy, arteriosclerosis), small vessel disease (microangiopathy, arteriolosclerosis), and microhemorrhages. Structural neuroimaging has been incorporated as an important element of the diagnosis of VaD [59].


Dementia

Dementia. Cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy is an autosomal- dominant hereditary small-artery vasculopathy caused by mutations in the notch3 gene on chromosome 19. Clinically, the disease is characterized by migraine with aura, strokes and progressive subcortical dementia, and mood disturbances. MRI in these patients shows focal lacunar infarcts and leukoaraiosis. Lesion load increases with age. Besides familial anamnesis and clinical history, structural MRI changes in these patients help to suggest the diagnosis by showing characteristic hyperintense T2 or fluid-attenuated inversion recovery lesions, which predominate in the frontal, parietal, and anterior temporal cortexes and in the external capsule [60]. Diagnosis is confirmed by skin biopsy or detection of a pathogenic notch3 mutation on direct sequencing.


Dementia

Dementia. CT Head Most acute stroke patients undergo brain imaging by unenhanced CT head to evaluate for size, territory, and acuity of infarct to exclude hemorrhage and evaluate for stroke mimics (such as brain tumors). Furthermore, the presence and severity of white matter changes and brain atrophy can also be readily determined from CT head imaging. CT head with IV contrast is not needed to evaluate VaD.


Dementia

Dementia. CTA Head CT angiography (CTA) is a sensitive modality and may be used as an alternative to MR angiography (MRA) to detect vascular occlusion or stenosis intracranially. However, vascular imaging is not needed to make a diagnosis of VaD; rather, the diagnosis relies on clinical criteria and evidence of end organ damage in the brain.


Dementia

Dementia. FDG-PET/CT Brain FDG-PET/CT in VaD can show multiple focal cortical and subcortical metabolic defects, a pattern different from AD and may be useful in differentiating the two entities in the demented patient [61]; however, it is not a first-line imaging test.


Dementia

Dementia. MR Spectroscopy Head MR spectroscopy shows injury to the axons by measuring the levels of NAA and Cr [62,63]. MR spectroscopy is a research tool and, to date, does not appear to clinically help establish a diagnosis of VaD or mixed VaD and AD.


Dementia

Dementia. MRA Head Although vascular imaging is not needed for diagnosis of suspected VaD, MRA is a sensitive modality to detect vascular occlusion or stenosis intracranially.


Dementia

Dementia. MRA Neck Vascular imaging is not needed for workup of suspected VaD.


Dementia

Dementia. MRI functional (fMRI) Head The use of fMRI is investigational and, to date, does not appear to clinically help establish a diagnosis of VaD or mixed VaD and AD.


Dementia

Dementia. MRI Head One of the roles of neuroimaging is to document the presence or absence of strokes. Although CT can detect the presence or absence of infarctions in patients with dementia, histopathologically verified cases of VaD with normal CT studies have been reported [28]. Thus, MRI is preferable to CT for detecting vascular lesions in patients with dementia. On MRI, evidence for vascular abnormalities includes cortical or subcortical infarcts, leukoariosis or white matter T2 hyperintensity, microhemorrhages, and lacunar infarct. Hippocampal atrophy has been seen in patients with vascular cognitive impairment [64], and some studies have argued that it is the best predictor of post stroke dementia [65].


Dementia

Dementia. The above-mentioned imaging findings on routine MRI lack specificity and correlation with degree of cognitive impairment. Diffusion tensor imaging has been shown to correlate better with cognitive deficits, but its use has been confined to research settings [66].


Dementia

Dementia. Differentiation of VaD from either AD with superimposed cerebrovascular disease or mixed AD and VaD is especially difficult and is best performed by amyloid PET/CT brain. On MRI, extensive infarctions (cortical or


Dementia

Dementia

Dementia. Dementia


Dementia

Dementia. lacunar or both) and white-matter changes (hyperintense on T2-weighted MRI) in a patient with dementia favor a contribution from VaD or mixed VaD and AD over AD. The absence or mild extent of these changes in a patient with dementia argues against a diagnosis of VaD. The abovementioned findings are optimally visualized on noncontrast MRI; IV contrast is not needed.


Dementia

Dementia. US Duplex Doppler Carotid Artery Atherosclerotic burden, as defined by carotid ultrasound (US), is associated with worse cognitive performance and subsequent cognitive decline [67]. However, US duplex Doppler is not needed to diagnose VaD.


Dementia

Dementia. Variant 5: Suspected idiopathic normal-pressure hydrocephalus. Initial imaging. Normal-pressure hydrocephalus (NPH) is characterized by the clinical triad of dementia, gait disturbance, and urinary incontinence. Other diagnostic features include normal CSF pressure at lumbar puncture, communicating hydrocephalus documented on MRI or CT, and ventricular influx but no passage of isotope over the convexities on radionuclide DTPA cisternography.


Dementia

Dementia. The Guideline Development, Dissemination, and Implementation Subcommittee of the AAN has concluded that shunting is possibly effective in idiopathic NPH (INPH) [68]. Several clinical, laboratory, and imaging signs can improve distinction between responders and nonresponders to shunting. However, there is no test or combination of clinical findings and tests that accurately predicts response to shunting. Clinical features that favor shunt responsiveness include predominance of gait disturbance, mild to moderate degree of dementia, and rapid clinical progression of urinary incontinence. Imaging features of responders versus nonresponders are discussed below.


Dementia

Dementia. CT Head CT head without IV contrast is an appropriate first-line imaging test to evaluate for ventriculomegaly out of proportion to sulci and to exclude other pathologies. It can also show transependymal CSF flow. CT head with IV contrast is not indicated for initial evaluation of NPH.


Dementia

Dementia. MR Spectroscopy Head MR spectroscopy is not useful in differentiating INPH from other types of dementia nor does it help in patient selection for ventriculoperitoneal shunting [69].


Dementia

Dementia. DTPA cisternography Radioisotope cisternogram using In-111-diethylenetriamine pentaacetic acid (DTPA) shows delayed clearance of radiotracer over the cerebral convexities and abnormal reflux of radiotracer into the ventricles. SPECT DTPA cisternography permits more accurate localization of radionuclide activity than planar DTPA cisternography, which partially superimposes different CSF compartments. However, there is insufficient evidence to determine whether patients with suspected INPH and persistent ventricular stasis on radioisotope DTPA cisternography would respond to shunting [68].


Dementia

Dementia. Dementia HMPAO SPECT or SPECT/CT Brain There is some suggestion that in patients with suspected INPH those with impaired cerebral blood flow reactivity (measured on Tc-99m HMPAO SPECT) to acetazolamide are possibly more likely to respond to shunting than those without impaired cerebral blood flow reactivity to acetazolamide [71]. This is a second-level test to stratify patients with INPH who may benefit from shunting.


Dementia

Dementia. Supporting Documents The evidence table, literature search, and appendix for this topic are available at https://acsearch.acr.org/list. The appendix includes the strength of evidence assessment and the final rating round tabulations for each recommendation.


Dementia

Dementia. For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Thoracic Back Pain

Thoracic Back Pain. Introduction/Background In the United States, spinal pain is one of the leading causes of disability, health care costs, and emergency room visits [1,2]. The lumbar and cervical spine regions have been extensively studied and have well-established associations with pain and disability. Comparatively, thoracic back pain (TBP) has received less attention in terms of genetic and epidemiological research [3]. However, the thoracic spine is a common site for inflammatory, neoplastic, metabolic, infectious, and degenerative conditions [3]. Therefore, TBP may be equally disabling and associated with significant morbidity.


Thoracic Back Pain

Thoracic Back Pain. Uncomplicated acute TBP and/or radiculopathy may be a benign, self-limited condition that does not warrant any imaging studies [5-8]. Imaging may be considered in those patients who have had up to 6 weeks of medical management and physical therapy that resulted in little or no improvement in their back pain. Imaging may also be considered for those patients presenting with red flags, raising suspicion for a serious underlying condition, such as symptomatic spinal canal stenosis, cord deformity or compression, malignancy, fracture, or infection [9,10].


Thoracic Back Pain

Thoracic Back Pain. For those patients with significant trauma, myelopathy, or prior thoracic spine fusion, early imaging may also be warranted [11-14]. Because the thoracic spine is a common site for osteoporotic compression fractures [15-17], early imaging should also be considered in patients with known osteoporosis or risk factors such as >65 years of age or chronic steroid use [18].


Thoracic Back Pain

Thoracic Back Pain. For those patients without neurologic compromise and who present with minor risk factors for cancer, inflammatory back disease (eg, ankylosing spondylitis), vertebral compression fracture, or symptomatic spinal stenosis, imaging may be considered after a trial of therapy.


Thoracic Back Pain

Thoracic Back Pain. Initial Imaging Definition Initial imaging is defined as imaging at the beginning of the care episode for the medical condition defined by the variant. More than one procedure can be considered usually appropriate in the initial imaging evaluation when:


Thoracic Back Pain

Thoracic Back Pain. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization.


Thoracic Back Pain

Thoracic Back Pain. Reprint requests to: publications@acr.org


Thoracic Back Pain

Thoracic Back Pain. OR Discussion of Procedures by Variant Variant 1: Adult. Acute Thoracic back pain without myelopathy or radiculopathy. No red flags. No prior management. Initial imaging. There is a lack of evidence supporting or refuting imaging early or before conservative treatment for TBP [3,20]. However, extrapolating from the low back pain (LBP) evidence, imaging is typically not warranted in this setting. Acute (<4 weeks duration), uncomplicated (no red flags) LBP with or without radiculopathy, is considered a self- limiting condition that is responsive to medical management and physical therapy in most patients [5-8]. Numerous studies have shown routine imaging provides no clinical benefit in this LBP group [6].


Thoracic Back Pain

Thoracic Back Pain. Thoracic disc disease is less common than in the cervical or lumbar spine [21]. This may be due to the fact that the thoracic spine is the only portion of the spine with additional structures (ie, ribs) to help in weight-bearing. There is also relatively limited mobility in the thoracic spine as the costovertebral joint limits flexion, the rib cage limits rotation and lateral bending, and the discs are relatively small in size compared to the cervical or lumbar spine. Symptomatic thoracic disc disease occurs most frequently below the level of T7. Thoracic disc abnormalities such as herniations, bulges, annular fissures, and cord contour deformity are common in asymptomatic patients [22]. Thoracic disc imaging abnormalities can therefore be seen in a substantial number of people without mid back pain.


Thoracic Back Pain

Thoracic Back Pain. With regards to thoracic facet joints, as in the lumbar spine, morphologic imaging changes of osteoarthritis do not correlate with pain [23].


Thoracic Back Pain

Thoracic Back Pain. Bone Scan Whole Body There is no relevant literature to support the use of bone scans whole body in the initial evaluation of acute uncomplicated TBP.


Thoracic Back Pain

Thoracic Back Pain. Bone Scan with SPECT or SPECT/CT Thoracic Spine There is no relevant literature to support the use of bone scans with single-photon emission CT (SPECT) or SPECT/CT thoracic spine in the initial evaluation of acute uncomplicated TBP.


Thoracic Back Pain

Thoracic Back Pain. CT Myelography Thoracic Spine There is no relevant literature to support the use of CT myelography thoracic spine in the initial evaluation of acute uncomplicated TBP. No radiologic distinction has been noted between asymptomatic and symptomatic discs on postmyelographic CT [24].


Thoracic Back Pain

Thoracic Back Pain. CT Thoracic Spine With IV Contrast There is no relevant literature to support the use of CT thoracic spine with intravenous (IV) contrast in the initial evaluation of acute uncomplicated TBP.


Thoracic Back Pain

Thoracic Back Pain. CT Thoracic Spine Without and With IV Contrast There is no relevant literature to support the use of CT thoracic spine without and with IV contrast in the initial evaluation of acute uncomplicated TBP.


Thoracic Back Pain

Thoracic Back Pain. CT Thoracic Spine Without IV Contrast There is no relevant literature to support the use of CT thoracic spine without IV contrast in the initial evaluation of acute uncomplicated TBP.


Thoracic Back Pain

Thoracic Back Pain. FDG-PET/CT Skull Base to Mid-Thigh There is no relevant literature to support the use of fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET/CT skull base to mid-thigh in the initial evaluation of acute uncomplicated TBP.


Thoracic Back Pain

Thoracic Back Pain. MRI Thoracic Spine With IV Contrast There is no relevant literature to support the use of MRI thoracic spine with IV contrast in the initial evaluation of acute uncomplicated TBP.


Thoracic Back Pain

Thoracic Back Pain

Thoracic Back Pain. Thoracic Back Pain


Thoracic Back Pain

Thoracic Back Pain. MRI Thoracic Spine Without and With IV Contrast There is no relevant literature to support the use of MRI thoracic spine without and with IV contrast in the initial evaluation of acute uncomplicated TBP.


Thoracic Back Pain

Thoracic Back Pain. MRI Thoracic Spine Without IV Contrast There is no relevant literature to support the use of MRI thoracic spine without IV contrast in the initial evaluation of acute uncomplicated TBP.


Thoracic Back Pain

Thoracic Back Pain. Radiography Thoracic Spine There is no relevant literature to support the use of radiography in the initial evaluation of acute uncomplicated TBP.


Thoracic Back Pain

Thoracic Back Pain. Variant 2: Adult. Subacute or chronic thoracic back pain without myelopathy or radiculopathy. No red flags. Failed conservative management. Initial imaging. As with acute TBP, few studies support or refute imaging for patients with subacute or chronic midback pain without neurologic symptoms. However, as with LBP, imaging is typically not considered useful in this setting [6,7]. For patients with subacute (4-12 weeks duration) or chronic (>12 weeks duration) TBP without red flags or prior management, conservative therapy should still be considered first-line [25].


Thoracic Back Pain

Thoracic Back Pain. Bone Scan Whole Body There is no relevant literature to support the use of bone scans whole body in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits.


Thoracic Back Pain

Thoracic Back Pain. Bone Scan with SPECT or SPECT/CT Thoracic Spine There is no relevant literature to support the use of bone scans with SPECT or SPECT/CT thoracic spine in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits.


Thoracic Back Pain

Thoracic Back Pain. CT Myelography Thoracic Spine There is no relevant literature to support the use of CT myelography thoracic spine in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits.


Thoracic Back Pain

Thoracic Back Pain. CT Thoracic Spine With IV Contrast There is no relevant literature to support the use of CT thoracic spine with IV contrast in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits.


Thoracic Back Pain

Thoracic Back Pain. CT Thoracic Spine Without and With IV Contrast There is no relevant literature to support the use of CT thoracic spine without and with IV contrast in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits.


Thoracic Back Pain

Thoracic Back Pain. CT Thoracic Spine Without IV Contrast There is no relevant literature to support the use of CT thoracic spine without IV contrast in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits.


Thoracic Back Pain

Thoracic Back Pain. FDG-PET/CT Skull Base to Mid-Thigh There is no relevant literature to support the use of FDG-PET/CT skull base to mid-thigh in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits.


Thoracic Back Pain

Thoracic Back Pain. MRI Thoracic Spine With IV Contrast There is no relevant literature to support the use of MRI thoracic spine with IV contrast in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits.


Thoracic Back Pain

Thoracic Back Pain. MRI Thoracic Spine Without and With IV Contrast There is no relevant literature to support the use of MRI thoracic spine without and with IV contrast in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits.


Thoracic Back Pain

Thoracic Back Pain. MRI Thoracic Spine Without IV Contrast There is no relevant literature to support the use of MRI thoracic spine without IV contrast in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits.


Thoracic Back Pain

Thoracic Back Pain. Radiography Thoracic Spine There is no relevant literature to support the use of radiography in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits.


Thoracic Back Pain

Thoracic Back Pain. Variant 3: Adult. Thoracic back pain with myelopathy or radiculopathy. Initial imaging. The goal of imaging is to identify potential actionable pain generators that could be targeted for medical treatment, intervention, or surgery. MRI of the thoracic spine has become the initial imaging modality of choice in these patients [13,26,27].


Thoracic Back Pain

Thoracic Back Pain. Thoracic myelopathy is most commonly due to compressive etiologies, including structural causes resulting in spinal canal stenosis, cord compression/deformity, or other inflammatory, infectious, vascular, or neoplastic etiologies [28]. Spinal stenosis is a common cause of myelopathy, typically from disc herniations (including giant calcified disc herniations), usually below T7, facet arthropathy, or ligamentum flavum ossification [29].


Thoracic Back Pain

Thoracic Back Pain. Symptomatic thoracic disc herniations are more common in patients in their third to fifth decades of life and, in more than one-third of patients, are associated with a history of trauma. On imaging, these are often calcified (20%- 65%) and sometimes intradural (5%-10%) [30]. Patients with symptomatic thoracic disc herniations may have thoracic midback pain (76%), motor/sensory deficit (61%), spasticity/hyperreflexia (58%), positive Babinski sign (55%), or bladder dysfunction (24%). Symptomatic thoracic disc herniations requiring surgery are rare, accounting for 1% to 2% of all discectomies [31]. Indication for surgery is usually severe, intractable pain, or progressive/severe myelopathy.


Thoracic Back Pain

Thoracic Back Pain. Thoracic radiculopathy is most commonly due to mechanical nerve root compression from degenerative, metabolic, infectious, or neoplastic causes.


Thoracic Back Pain

Thoracic Back Pain. Bone Scan Whole Body There is no relevant literature to support the use of whole-body bone scans in the initial imaging of TBP and myelopathy or radiculopathy.


Thoracic Back Pain

Thoracic Back Pain. Bone Scan with SPECT or SPECT/CT Thoracic Spine There is no relevant literature to support the use of bone scan with SPECT or SPECT/CT in the initial imaging of TBP and myelopathy or radiculopathy.


Thoracic Back Pain

Thoracic Back Pain. CT Myelography Thoracic Spine CT myelography of the thoracic spine can be useful in assessing the patency of the spinal canal/thecal sac. CT myelography may also be complementary to MRI for identifying and differentiating between certain causes of myelopathy, such as ventral cord herniation versus dorsal thoracic arachnoid web or cyst, and also for presurgical or preradiation treatment planning due to its high detail and exquisite resolution of the contents of the spinal canal [32]. CT myelography has the disadvantage of requiring lumbar puncture for intrathecal injection of myelographic contrast.


Thoracic Back Pain

Thoracic Back Pain. CT Thoracic Spine With IV Contrast There is no relevant literature to support the use of CT thoracic spine with IV contrast in the initial imaging of TBP and myelopathy or radiculopathy.


Thoracic Back Pain

Thoracic Back Pain. CT Thoracic Spine Without and With IV Contrast There is no relevant literature to support the use of CT thoracic spine without and with IV contrast in the initial imaging of TBP and myelopathy or radiculopathy.


Thoracic Back Pain

Thoracic Back Pain. CT Thoracic Spine Without IV Contrast There is no relevant literature to support the use of CT thoracic spine without IV contrast in the initial imaging of TBP and myelopathy or radiculopathy. However, CT thoracic spine without IV contrast may be useful for preoperative planning. CT delineates osseous structures and anatomy with high resolution and can aid in trajectory planning for hardware fixation.


Thoracic Back Pain

Thoracic Back Pain. FDG-PET/CT Skull Base to Mid-Thigh There is no relevant literature to support the use of FDG-PET/CT skull base to mid-thigh in the initial imaging of TBP and myelopathy or radiculopathy.


Thoracic Back Pain

Thoracic Back Pain. MRI Thoracic Spine With IV Contrast MRI thoracic spine with IV contrast is not typically performed independently as an initial study, because its interpretation is most informative when correlated with standard noncontrast sequences included in MRI thoracic spine with and without IV contrast.


Thoracic Back Pain

Thoracic Back Pain

Thoracic Back Pain. Thoracic Back Pain


Thoracic Back Pain

Thoracic Back Pain. MRI Thoracic Spine Without and With IV Contrast MRI thoracic spine without and with IV contrast may be the preferred initial study of choice in patients with TBP and myelopathy/radiculopathy when underlying malignancy, infection, or inflammation is clinically suspected.


Thoracic Back Pain

Thoracic Back Pain. MRI Thoracic Spine Without IV Contrast MRI thoracic spine without IV contrast may be useful as an initial study of choice in patients with TBP and myelopathy/radiculopathy when structural/mechanical causes of compressive myelopathy or radiculopathy are clinically suspected. MRI thoracic spine without IV contrast is most useful in evaluating compressive myelopathy or radiculopathy because of its ability to accurately depict soft tissue pathology, assess vertebral marrow, and assess the spinal canal patency [20]. Heavily T2-weighted sequences such as CISS/FIESTA may be helpful to assess for structural etiologies such as dorsal thoracic arachnoid webs or for reducing metallic artifacts in patients with thoracic spinal hardware [33].


Thoracic Back Pain

Thoracic Back Pain. Radiography Thoracic Spine There is no relevant literature to support the use of thoracic spine radiography in the initial evaluation of patients with TBP and myelopathy. Radiography alone is not usually sufficient for diagnosing the specific pain generator in these patients or for guiding surgical or interventional options without MRI and/or CT imaging. However, it can provide complementary information that can be helpful in treatment planning, including for presurgical planning and postoperative assessment [11].


Thoracic Back Pain

Thoracic Back Pain. Variant 4: Adult. Thoracic back pain without or with myelopathy or radiculopathy. One or more of the following: low-velocity trauma, osteoporosis, elderly individual, or chronic steroid use. Initial imaging. Elderly (>65 years of age) individuals, those with known osteoporosis, prior benign nontraumatic compression fracture, or chronic steroid use are at risk for additional compression fractures even with minimal to no trauma [34,35].


Thoracic Back Pain

Thoracic Back Pain. Patients with low-velocity trauma, and without risk factors for osteoporosis, may not need dedicated thoracic spine imaging if asymptomatic.


Thoracic Back Pain

Thoracic Back Pain. Bone Scan Whole Body Whole-body bone scans may be helpful in the setting of compression fracture(s) to help identify fracture acuity and to appropriately select patients for intervention [36], particularly if MRI cannot be safely/easily obtained.


Thoracic Back Pain

Thoracic Back Pain. Bone Scan with SPECT or SPECT/CT Thoracic Spine Bone scan with SPECT or SPECT/CT may be helpful in the setting of compression fracture(s) to help identify fracture acuity and to appropriately select patients for intervention [36].


Thoracic Back Pain

Thoracic Back Pain. CT Myelography Thoracic Spine There is no relevant literature to support the use of CT myelography thoracic spine in the initial imaging assessment of this group.


Thoracic Back Pain

Thoracic Back Pain. CT Thoracic Spine With IV Contrast There is no relevant literature to support the use of CT thoracic spine with IV contrast in the initial imaging assessment of this group.


Thoracic Back Pain

Thoracic Back Pain. CT Thoracic Spine Without and With IV Contrast There is no relevant literature to support the use of CT thoracic spine without and with IV contrast in the initial imaging assessment of this group.


Thoracic Back Pain

Thoracic Back Pain. CT Thoracic Spine Without IV Contrast CT thoracic spine without IV contrast may be useful as an initial study in the emergency room setting or for presurgical planning, particularly if radiographs are negative [36].


Thoracic Back Pain

Thoracic Back Pain. FDG-PET/CT Skull Base to Mid-Thigh There is no relevant literature to support the use of FDG-PET/CT skull base to mid-thigh in the initial imaging assessment of this group.


Thoracic Back Pain


Thoracic Back Pain

Thoracic Back Pain. MRI Thoracic Spine Without and With IV Contrast MRI thoracic spine without and with IV contrast is not typically performed as an initial study in this group unless there is concern for underlying neoplasm, infection, or inflammation.


Thoracic Back Pain

Thoracic Back Pain. MRI Thoracic Spine Without IV Contrast MRI thoracic spine without IV contrast may be useful as an initial study in this group due to its excellent soft tissue resolution, particularly if there is concern for soft tissue or neurologic compressive injury, to identify a compression fracture (even if radiographs are negative), or to plan intervention (identify marrow edema) [36].


Thoracic Back Pain

Thoracic Back Pain. Radiography Thoracic Spine Radiography may be useful as an initial screening study in TBP with risk factors for osteoporotic fractures in patients without neurologic deficits [35]. However, it should be noted that thoracic vertebral body fractures seen on radiographs may be difficult to estimate in terms of chronicity without priors to compare to. In those cases, MRI or bone scan may be needed to age the fracture acuity.


Thoracic Back Pain

Thoracic Back Pain. Bone Scan Whole Body There is no relevant literature to support the use of whole-body bone scan in the initial imaging assessment of this group.


Thoracic Back Pain

Thoracic Back Pain. Bone Scan with SPECT or SPECT/CT Thoracic Spine There is no relevant literature to support the use of bone scans with SPECT or SPECT/CT in the initial imaging assessment of this group.


Thoracic Back Pain

Thoracic Back Pain. CT Myelography Thoracic Spine CT myelography of the thoracic spine may be helpful in patients or for treatment planning (surgery, radiation).


Thoracic Back Pain

Thoracic Back Pain. CT Thoracic Spine Without IV Contrast CT thoracic spine without IV contrast may be helpful for presurgical planning or to delineate the osseous anatomy, particularly if there is osseous destruction [37].


Thoracic Back Pain

Thoracic Back Pain. MRI Thoracic Spine With IV Contrast MRI thoracic spine with IV contrast is not typically performed independently as an initial study, because its interpretation is most informative when correlated with standard noncontrast sequences included in MRI thoracic spine with and without IV contrast.


Thoracic Back Pain

Thoracic Back Pain. MRI Thoracic Spine Without and With IV Contrast MRI without and with IV contrast is the initial imaging modality of choice in patients with TBP and suspected neoplasm or infection [36,38-42].


Thoracic Back Pain

Thoracic Back Pain

Thoracic Back Pain. Thoracic Back Pain


Thoracic Back Pain

Thoracic Back Pain. MRI Thoracic Spine Without IV Contrast MRI without IV contrast may be useful in this setting to identify marrow replacing lesions, osseous destruction, canal compromise, and cord signal abnormality. However, the addition of postcontrast sequences would be more sensitive in identifying thoracic spinal infection and its complications, assessing small marrow replacing lesions, and identifying intradural disease [39-44].


Thoracic Back Pain

Thoracic Back Pain. Radiography Thoracic Spine Radiographs have low sensitivity but may be useful in the urgent/emergent setting to identify osseous destruction or change in alignment in patients with TBP and suspected infection or neoplasm [45].


Thoracic Back Pain

Thoracic Back Pain. Variant 6: Adult. Thoracic back pain without or with myelopathy or radiculopathy. Radiograph shows bone destruction or fracture or spinal deformity. Next imaging study. In patients with TBP and osseous destruction or spinal deformity the role of imaging is to delineate osseous detail and anatomy and assess the integrity of the soft tissue and neural structures, particularly that of the spinal canal. Additionally, if spinal hardware is present, assessing hardware integrity and position is also a common indication for imaging. More than one imaging modality may be indicated for diagnosis and treatment planning.


Thoracic Back Pain

Thoracic Back Pain. Bone Scan Whole Body There is no relevant literature to support the use of whole body bone scans in the initial imaging assessment of this group.


Thoracic Back Pain

Thoracic Back Pain. Bone Scan with SPECT or SPECT/CT Thoracic Spine There is no relevant literature to support the use of bone scan with SPECT or SPECT/CT in the initial imaging assessment of this group.


Thoracic Back Pain

Thoracic Back Pain. CT Myelography Thoracic Spine CT myelography may be useful in this setting in patients with spinal hardware.


Thoracic Back Pain

Thoracic Back Pain. CT Thoracic Spine With IV Contrast There is no relevant literature to support the use of CT thoracic spine with IV contrast in the initial imaging assessment of this group.


Thoracic Back Pain

Thoracic Back Pain. CT Thoracic Spine Without and With IV Contrast CT thoracic spine without and with IV contrast may be useful in this clinical scenario.


Thoracic Back Pain

Thoracic Back Pain. CT Thoracic Spine Without IV Contrast In patients with TBP with or without myelopathy or radiculopathy when there is evidence of osseous destruction or spinal deformity on radiographs, both MRI and CT may be useful as an initial imaging modality [11,46]. CT can better depict the osseous detail, and MRI is more useful for assessing the integrity of the soft tissue and neural structures, particularly that of the spinal canal.


Thoracic Back Pain

Thoracic Back Pain. FDG-PET/CT Skull Base to Mid-Thigh There is no relevant literature to support the use of FDG-PET/CT skull base to mid-thigh in the initial imaging assessment of this group.


Thoracic Back Pain


Thoracic Back Pain

Thoracic Back Pain. MRI Thoracic Spine Without and With IV Contrast MRI thoracic spine without and with IV contrast may be useful as an imaging study in patients with TBP and evidence of spinal deformity or osseous destruction on radiography, particularly if there is concern for infection or neoplasm [44].


Thoracic Back Pain

Thoracic Back Pain. MRI Thoracic Spine Without IV Contrast MRI without IV contrast may be useful in this setting to identify marrow replacing lesions, osseous destruction, canal compromise, and cord signal abnormality [27]. However, the addition of postcontrast sequences would be more sensitive in identifying thoracic spinal infection and its complications, assessing small marrow replacing lesions, and identifying intradural disease.


Thoracic Back Pain

Thoracic Back Pain. Variant 7: Adult. Thoracic back pain without or with myelopathy or radiculopathy. Post thoracic spine surgery. Follow-up imaging. In patients with TBP and a history of spinal fixation, imaging plays an important role in assessing hardware position and integrity, assessing spinal alignment, assessing fusion, identifying findings suspicious for infection, and assessing for postoperative complications, including, but not limited to, postoperative collections, scarring, adjacent segment degeneration, and spinal deformity [47].


Thoracic Back Pain

Thoracic Back Pain. Several imaging modalities may be useful and complementary in the initial assessment of patients with TBP and a history of instrumented spinal fixation [43,45,47].


Thoracic Back Pain

Thoracic Back Pain. Bone Scan Whole Body There is no relevant literature to support the use of whole-body bone scans in the initial imaging assessment of this group.


Thoracic Back Pain

Thoracic Back Pain. Bone Scan with SPECT or SPECT/CT Thoracic Spine There is limited literature to support the use of bone scan with SPECT or SPECT/CT thoracic spine in the initial imaging assessment of this group.


Thoracic Back Pain

Thoracic Back Pain. CT Myelography Thoracic Spine CT myelography may also be helpful in patients in whom a compressive etiology of their symptoms is clinically suspected.


Thoracic Back Pain

Thoracic Back Pain. CT Thoracic Spine Without and With IV Contrast There is no relevant literature to support the use of CT thoracic spine without and with IV contrast in the initial imaging assessment of this group.


Thoracic Back Pain

Thoracic Back Pain. CT Thoracic Spine Without IV Contrast CT thoracic spine without IV contrast may be useful in assessing the integrity of fusion, identifying hardware position and integrity, and assessing alignment.


Thoracic Back Pain

Thoracic Back Pain. MRI Thoracic Spine With IV Contrast MRI thoracic spine with IV contrast is not typically performed independently as an initial study, because its interpretation is most informative when correlated with standard noncontrast sequences included in MRI thoracic spine with and without IV contrast.


Thoracic Back Pain

Thoracic Back Pain. MRI Thoracic Spine Without and With IV Contrast MRI thoracic spine without and with IV contrast may be helpful in assessing for postoperative infection, hematoma, postoperative collections, or canal compromise. Many of these patients may benefit from scanning on mid field or 1.5T MRI scanners with metallic susceptibility artifact reduction protocols [46,47].


Thoracic Back Pain

Thoracic Back Pain. MRI Thoracic Spine Without IV Contrast MRI thoracic spine without IV contrast may help assess for postoperative hematoma or other collections, neurologic injury, residual foramina or canal stenosis, or cord compression.


Thoracic Back Pain

Thoracic Back Pain. Radiography Thoracic Spine Radiographs may be useful for assessing the integrity of fusion, confirming hardware position and integrity, identifying adjacent level degeneration, and assessing alignment.


Thoracic Back Pain

Thoracic Back Pain. Supporting Documents The evidence table, literature search, and appendix for this topic are available at https://acsearch.acr.org/list. The appendix includes the strength of evidence assessment and the final rating round tabulations for each recommendation.


Thoracic Back Pain

Thoracic Back Pain. For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Thoracic Back Pain

Thoracic Back Pain

Thoracic Back Pain. Thoracic Back Pain


Staging of Pancreatic Ductal Adenocarcinoma. Introduction/Background Prevalence, Etiology, Treatment, and Prognosis According to the American Cancer Society, the number of new pancreatic cancer cases estimated in the United States in 2017 is 53,670 [1]. The estimated number of deaths is 43,090 in 2017, with pancreatic adenocarcinoma remaining the fourth leading cause of cancer-related death in the United States. Difficulty in early detection and lack of effective screening methods invariably results in an advanced stage at presentation and poor prognosis.


Staging of Pancreatic Ductal Adenocarcinoma. Associated risk factors include tobacco use (20% of patients), family history of pancreatic cancer (two or more first-degree relatives with pancreatic cancer reported in 10% of patients), chronic pancreatitis, diabetes, obesity, hereditary pancreatitis [2-4] and genetic alterations such as BRCA1, BRCA2, PALB2, p16 gene mutations, Lynch syndrome, and Peutz-Jeghers syndrome [5,6]. Screening is not currently recommended for the general population (US Preventive Services Task Force gives a D recommendation) [7]. However, some have suggested that screening patients at high risk of developing pancreatic cancer is feasible, while acknowledging that data for cost- effectiveness and benefit are still required [8]. To date, the most suitable imaging technology for such screening is unclear [5]. No specific tumor markers for pancreatic cancer exist, and although most patients will demonstrate elevation in serum cancer antigen 19-9, this has low specificity and is more often used to indicate disease progression.


Staging of Pancreatic Ductal Adenocarcinoma. Pancreatic cancer develops insidiously in the exocrine cells, and as such, early disease is often asymptomatic or presents with vague symptoms such as loss of appetite, fatigue, and general malaise. Consequently, 80% to 85% of patients present with advanced disease without the option of surgical resection [9].


Staging of Pancreatic Ductal Adenocarcinoma. Overall survival for pancreatic cancer is 28% after 1 year and 7% after 5 years [1]. Localized pancreatic cancer, reportedly diagnosed in 9% of patients, is associated with a 26% 5-year survival. Distant stage disease at diagnosis is associated with only a 15% 1-year and 2% 5-year survival [1]. Given the poor prognosis, accurate staging is essential and pivotal to patient management decisions that are decided through a multidisciplinary approach [5]. Imaging plays a critical role in pancreatic cancer staging and therapeutic decision process. The imaging armamentarium used to evaluate pancreatic cancer includes multidetector computed tomography (MDCT), magnetic resonance imaging (MRI), endoscopic ultrasound (EUS), and fluorine-18-2-fluoro-2-deoxy- D-glucose positron emission tomography (FDG-PET)/CT.


Staging of Pancreatic Ductal Adenocarcinoma. aPrincipal Author, University of Texas MD Anderson Cancer Center, Houston, Texas. bResearch author, University of Texas MD Anderson Cancer Center, Houston, Texas. cPanel Chair, Johns Hopkins University School of Medicine, Baltimore, Maryland. dMemorial Sloan Kettering Cancer Center, New York, New York; American College of Surgeons. eUniversity of Arizona, Banner University Medical Center, Tucson, Arizona. fMontefiore Medical Center, Bronx, New York. gColumbia University, New York, New York; American Gastroenterological Association. hUniversity of Florida College of Medicine, Gainesville, Florida. iNew York University Medical Center, New York, New York. jNorthwestern University, Chicago, Illinois. kUniversity of Texas MD Anderson Cancer Center, Houston, Texas. lUniversity of Alabama Medical Center, Birmingham, Alabama. mThe Warren Alpert School of Medicine at Brown University, Providence, Rhode Island. nUniversity of Illinois College of Medicine, Chicago, Illinois; American College of Physicians. oSpecialty Chair, University of Washington, Seattle, Washington.


Staging of Pancreatic Ductal Adenocarcinoma. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through society representation on expert panels. Participation by representatives from collaborating societies on the expert panel does not necessarily imply individual or society endorsement of the final document.


Staging of Pancreatic Ductal Adenocarcinoma. Reprint requests to: publications@acr.org


Staging of Pancreatic Ductal Adenocarcinoma. Staging of Pancreatic Ductal Adenocarcinoma Key determinants of tumor stage can be summarized as follows: Stage IV disease is the presence of any distant metastases, stage III disease is any T4 disease, stage IIA disease is T3 disease with no distant metastases or nodal involvement, stage IIB disease is T1 through T3 disease with nodal involvement, stage IA is T1 disease without nodal involvement, and stage IB is T2 disease without nodal involvement.


Staging of Pancreatic Ductal Adenocarcinoma. Treatment options include surgery, radiation therapy, and chemotherapy. Radical surgical resection offers potentially curative therapy, though it is seldom achieved. Furthermore, the general procedure-related morbidity rate is high at 20% and mortality rate is 1% to 4% [10,11].


Staging of Pancreatic Ductal Adenocarcinoma. Less than 20% of patients are candidates for surgery. For those undergoing surgery, the cancer is often too extensive for removal. Adjuvant chemotherapy with gemcitabine or chemoradiation after surgery has been reported by some to improve survival, but this is controversial due to conflicting published results [12-15]. Use of combination systemic therapy with gemcitabine and the targeted anticancer drug erlotinib, has been suggested to slightly increase survival in patients with advanced cancer [1].


Staging of Pancreatic Ductal Adenocarcinoma. Cure rates are highest for tumors that are truly localized to the pancreas (without extension beyond the pancreatic capsule or lymph node metastases). Surgical resection of small, localized tumors, (measuring <2 cm in maximum diameter), are associated with a survival rate of 18% to 24% [16].


Staging of Pancreatic Ductal Adenocarcinoma. Decisive factors determining tumor resectability include presence of distant metastases, and vascular involvement particularly the celiac axis, superior mesenteric artery (SMA), superior mesenteric vein (SMV), and portal vein (PV). Motivation in efforts to increase surgical candidates is consequent to complete tumor resection being the sole option for cure. Close collaborative efforts between surgeons, oncologists, radiation oncologists, and diagnostic imaging has resulted in the development of resectable and borderline resectable disease criteria over the last decade. Increasingly sophisticated surgical techniques, including complex vascular reconstruction and use of neoadjuvant and adjuvant therapies have increased demand of more detailed and specific radiological interpretation of disease extent. Surgical definition of borderline resectable pancreatic cancer is based on five important observations: 1) long-term survival necessitates complete resection of the primary tumor and regional lymph nodes; 2) negative resection margins are less likely with increasing tumor involvement of the SMV-PV and SMA; 3) SMV-PV and hepatic artery resection (not SMA) at pancreatectomy has been associated with acceptable outcomes; 4) administration of conventional cytotoxic agents rarely results in down-staging locally advanced pancreatic cancer; and 5) tumor response to neoadjuvant chemotherapy and chemoradiation may be indicative of favorable tumor physiology and biology, and thus used to select patients who may benefit from aggressive surgery [17-25].


Staging of Pancreatic Ductal Adenocarcinoma. Overview of Imaging Modalities Radiologic evaluation of patients with pancreatic cancer for staging should assess tumor size, extension of tumor beyond the pancreas including adjacent significant vasculature (namely the SMA, celiac artery, common hepatic artery, and splenic artery, hepatic arterial variants, and the main PV, splenic vein, SMV, and whether the tumor is extending to divisions of these veins, which would preclude placement of a graft), presence of regional adenopathy (especially nodes that may be beyond the surgical field and may be suspicious, based on size or morphology), and whether there is metastatic involvement of the liver, peritoneum, and lungs.


Staging of Pancreatic Ductal Adenocarcinoma. CT CT At many institutions, contrast-enhanced MDCT is the preferred imaging technique for the staging of pancreatic cancer. It is quick, robust, and especially has superb spatial resolution. It is particularly useful for the assessment of tumor involvement of vascular structures. Imaging should be obtained as a multiphasic acquisition, with a late arterial phase timed to optimize peak enhancement of the pancreas (typically at 45-50 seconds after the start of contrast injection, depending on injection rate) to maximize visualization of the primary tumor, and a portal venous phase for optimum enhancement of venous structures and to maximize detectability of typically hypodense liver metastases (typically 70 seconds after the start of contrast injection) [28]. Many practices employ use of bolus tracking to optimize timing of the arterial and portal venous phase of enhancement. A recent study comparing 64-detector row MDCT and 3T MRI showed overall comparable sensitivities and specificities between the two modalities regarding resectability (CT sensitivity 87%, specificity 63% to 75%; MRI sensitivity 93%, specificity 50% to 75%) [11]. A recent critical review of CT and MRI that was based on reports published between 1997 and 2009 also showed that CT and MRI performed comparably with both modalities showing improvement on more recent studies [29]. Notably, unenhanced CT has poor soft tissue contrast in comparison to MRI and therefore has marginal usefulness during staging. It should also be noted anecdotally, for the reasons given above, that in those institutions with MRI and CT capabilities, CT is typically the more used modality in the setting of staging pancreatic cancer.


Staging of Pancreatic Ductal Adenocarcinoma. MRI Many MRI advances have been made in the past several years with regard to robustness of image quality, speed of image acquisition, and resolution in imaging. As noted above, MRI has been reported in a recent study to have a sensitivity of 93% and specificity of 50% to 75% for determination of resectability [11], and studies comparing state-of-the-art CT with state-of-the-art MRI report a similar overall performance [29]. MRI has inherently better soft tissue contrast than unenhanced CT enabling superior visualization of tumor without intravenous (IV) contrast administration. Although we could not identify studies specifically addressing noncontrast MRI staging sensitivity and specificity, MRI is preferable because techniques such as flow sensitive sequences and diffusion- weighted imaging provide valuable information when IV contrast is contraindicated.


Staging of Pancreatic Ductal Adenocarcinoma. FDG-PET/CT There is considerable variation in how FDG-PET/CT is performed between institutions, with regard to the presence or absence of IV contrast, the presence or absence of oral contrast, as well as other parameters including slice thickness, and field-of-view. When performed without IV contrast, FDG-PET/CT has the same limitations as unenhanced CT with regard to local staging of the tumor. When performed with IV contrast, images are typically obtained at a single phase of contrast enhancement. Studies that have recently examined the role of FDG-PET/CT in the staging of pancreatic cancer have focused on its supplementary ability to detect additional distant metastases beyond those detected by conventional cross-sectional imaging of the abdomen and pelvis or chest, abdomen, and pelvis given the advantage that FDG-PET/CT is a whole-body examination [31].


Staging of Pancreatic Ductal Adenocarcinoma. Nodal staging is a limitation for any of the imaging modalities because of its relative insensitivity to micrometastases detection. Another challenge is the varying imaging criteria for identifying potential nodal involvement between studies. A recent study that used, as criterion for nodal involvement, a nodal short axis diameter of >5 mm or morphologic features of necrosis showed an accuracy of 55% to 60% for the detection of nodal metastatic disease, which is similar to findings seen on older studies regardless of criteria (44%-68%) [29,32,34,35].


Staging of Pancreatic Ductal Adenocarcinoma. Little information is available regarding sensitivity for detecting liver metastases originating from pancreatic cancer for the current generation of MDCT scanners (64-detector row or better). Two studies that have compared 64-detector row MDCT with 3T MRI showed for CT a sensitivity of 70% to 76% in the detection of liver metastases compared to 90% to 100% for MRI with either gadobenate dimeglumine or gadoxetic acid [33,36]. Ikuta et al [37] studied 192 patients to compare 4-detector row multiphasic MDCT with CT arterial portography (CTAP) and computed tomography-assisted hepatic arteriography (CTHA) with intraoperative US as the gold standard in the assessment of those patients identified as not having metastatic disease. Of note, CTAP with CTHA is an invasive technique requiring a separate interventional procedure for placement of an arterial catheter to optimize contrast evaluation by CT, and as such is not practiced routinely. Furthermore, MDCT was performed with only four detectors, which is far less than many contemporary scanners. In that study, MDCT had a sensitivity of 48.4% and specificity of 98% for liver metastases compared to CTAP + CTHA, which had a sensitivity of 94.2% and specificity of 82.7%. Although the results of CTAP + CTHA were impressive, the data regarding current state-of-the-art MDCT are not representative of modern practice.


Staging of Pancreatic Ductal Adenocarcinoma. Peritoneal metastases from pancreatic cancer are typically difficult to identify by any of the modalities because of their typically small size or miliary appearance. In our literature search, no studies that tried to assess overall sensitivity for peritoneal metastases by CT were available, likely because patients were already found to have unresectable disease secondary to other causes such as liver metastases or extensive vascular involvement. Studies that were retrieved in our examination focused on the question of the additional usefulness of preoperative laparoscopic assessment following CT. Results have been controversial, but indirectly these provide information regarding whether CT is sufficient for detection of peritoneal disease for disease management. A meta-analysis of 1,015 patients across 15 studies concluded that, on average, out of 100 patients identified as having resectable disease based on CT, use of follow-up laparoscopy would have avoided 23 unnecessary laparotomies [38]. Another recent meta-analysis that analyzed 12 studies between 1999 and 2010 showed a pooled sensitivity of laparoscopic assessment of 75% for peritoneal implants [39]. In our anecdotal experience, institutions will variably use laparoscopy, sometimes in the setting of suspicion for peritoneal disease, but for some others more globally, with or without laparoscopic peritoneal washing, with the plan to proceed directly to laparotomy at the same setting for planned pancreatic resection in the absence of detection of peritoneal disease.


Staging of Pancreatic Ductal Adenocarcinoma. MRI The limitations noted above for studies regarding CT and the accuracy of assessing vascular involvement by tumor apply to MRI as well (with differences in criteria for defining a vessel as involved by tumor, differences in definitions of resectability, and varying generations of equipment, etc.). Fewer studies are available on the topic of MRI and staging of pancreatic cancer than there are for CT. A study comparing 64-detector row MDCT versus 3T MRI showed for MRI a sensitivity for vascular infiltration of 50% to 80% and a specificity of 96% to 98% [11]. These findings are similar to those found on a meta-analysis of eight studies published between 1997 and 2004 that showed a pooled sensitivity of 67% and pooled specificity of 94% that was not significantly different


Staging of Pancreatic Ductal Adenocarcinoma. Staging of Pancreatic Ductal Adenocarcinoma from CT [33]. Therefore, MRI and CT can be considered likely comparable with regard to assessment of vascular involvement by tumor.


Staging of Pancreatic Ductal Adenocarcinoma. As noted above, assessment for nodal staging on cross-sectional imaging is limited because of its current inability to identify micrometastases. A critical review article on staging reportedly noted an accuracy ranging from 61% to 77% in radiology studies from 2004 to 2009 for the detection of nodal involvement by tumor [29].


Staging of Pancreatic Ductal Adenocarcinoma. In contrast, MRI has been shown to be likely superior for the detection of liver metastases. Two studies that compared 64-detector row MDCT with 3T MRI showed that CT had a sensitivity of 70% to 76% for the detection of liver metastases compared to 90% to 100% for MRI with either gadobenate dimeglumine or gadoxetic acid [33,36].


Staging of Pancreatic Ductal Adenocarcinoma. The literature search identified only very limited information with regard to MRI and pancreatic cancer peritoneal metastases. A study evaluating the usefulness of staging laparoscopy following staging MRI noted that the yield of staging laparoscopy was marginal and cost effectiveness was reportedly poor for use of this approach [40].


Staging of Pancreatic Ductal Adenocarcinoma. EUS EUS A recent meta-analysis of 29 studies that incorporated EUS showed EUS to have a pooled sensitivity of 85% and specificity of 91% for vascular invasion [41]. Notably, the same study noted that the criteria for identifying arterial invasion have not been standardized, which is a constraining factor when attempting to compare between modalities and likely accounts for the wide range of sensitivity for vascular invasion of EUS in this meta-analysis (62% to 100%). The authors noted in their review that there are little comparative data between arterial and venous assessments, and that overall it appeared that CT and EUS performed comparably for assessing venous involvement and that CT may be superior for the assessment of invasion of arterial structures [41].


Staging of Pancreatic Ductal Adenocarcinoma. With regard to nodal disease, EUS has the advantage in that it can be combined with FNA to greatly improve its specificity. A recent meta-analysis of 8 studies showed a pooled sensitivity of 58% and specificity of 85% for detecting nodal metastases with EUS alone [41]. Although the meta-analysis did not include an assessment of multiple studies with EUS that included FNA, the authors did note that EUS would likely improve nodal staging, and cited a study that reported a sensitivity of 82% and specificity of 100% to confirm malignant adenopathy [42].


Staging of Pancreatic Ductal Adenocarcinoma. Because of its narrow field-of-view, and the limited region of anatomic coverage, EUS does not have a role for assessment of peritoneal disease. EUS allows for a limited examination of the left liver lobe and possible FNA of these lesions. No studies have directly compared the accuracy of EUS and cross-sectional imaging for left-sided liver metastasis. Imaging of the right liver is difficult and unreliable by EUS.


Staging of Pancreatic Ductal Adenocarcinoma. US Difficulties in visualizing the pancreas in detail because of either body habitus or commonly interposed bowel gas limit the usefulness of transabdominal US for staging.


Staging of Pancreatic Ductal Adenocarcinoma. FDG-PET/CT As noted earlier, there is considerable variability in how the CT portion of the examination is obtained for FDG- PET/CT with regard to whether IV or oral contrast is administered. When performed without IV contrast, it does not have a role in the assessment for potential vascular involvement. When performed with IV contrast enhancement, it is typically acquired as a single phase of contrast enhancement at variable slice thickness and variable reconstructed display field-of-view between institutions. These parameters would affect the usefulness and effectiveness of local staging. FDG-PET/CT, when used in the setting of preoperative staging, is therefore typically used as a whole-body examination for follow-up to contrast-enhanced CT or MRI, which themselves would already provide information regarding liver metastases, potential peritoneal implants, and possible adenopathy. This is likely why most of the studies retrieved in our literature search evaluated the usefulness of FDG-PET/CT as a follow-up study whole body examination to conventional cross-sectional imaging for the detection of unexpected distant metastases. One of the challenges encountered in evaluating the studies, is that often distant metastases (liver, peritoneal, lung, bone, nodes) were put together into a single group rather than subgroups by the type of distant metastasis. The results are variable across studies with the detection rate of unexpected distant metastases generally identified in patients as probably resectable based on contrast-enhanced CT or MRI, ranging from 2.5% to 41% [43-48]. A recent meta-analysis of FDG-PET/CT imaging (4 studies, 101 patients) showed a pooled sensitivity of 64% and specificity of 81% for metastatic nodal disease, and a sensitivity of 67% and specificity of 96% for liver metastases [49].


Staging of Pancreatic Ductal Adenocarcinoma. Staging of Pancreatic Ductal Adenocarcinoma Variant 2: Pancreatic ductal adenocarcinoma. Follow-up post-neoadjuvant therapy. Evaluate resectability for borderline resectable tumor. Only five articles that addressed the topic of preoperative therapy in the context of staging a tumor were identified in the literature search.


Staging of Pancreatic Ductal Adenocarcinoma. CT CT Only very limited information is available regarding staging in the setting of preoperative chemotherapy and/or radiation therapy. Challenges include differences in treatment regimens. A small study comparing 31 patients who had undergone neoadjuvant therapy (between 2005 and 2010) for locally advanced disease that went on to attempted curative resection with a control group of 41 patients who went directly to surgery showed that the accuracy of MDCT (in this study, 16- and 64-detector row) for determining resectability was significantly less in the neoadjuvant group (58% versus 83%), primarily secondary to an overestimation of vascular invasion [50]. This study was limited by a mix of treatment regimens including chemotherapy alone, radiation therapy alone, and combination chemoradiation. Other studies have also shown that imaging signs of vascular involvement by tumor persist even after successful therapy because of the inability of imaging to distinguish viable from nonviable tumor [51,52]. No information was available from our search in regard to the accuracy of identifying nodal metastases, liver metastases, or peritoneal disease in the setting of neoadjuvant therapy.


Staging of Pancreatic Ductal Adenocarcinoma. MRI The literature search did not identify any studies that examined the accuracy of MRI in the assessment of staging following preoperative therapy.


Staging of Pancreatic Ductal Adenocarcinoma. EUS The literature search did not identify any studies that examined the accuracy of EUS in the assessment of vascular involvement by tumor following neoadjuvant therapy.


Staging of Pancreatic Ductal Adenocarcinoma. US The literature search did not identify any studies that examined the accuracy of transabdominal US in the assessment of vascular involvement by tumor following neoadjuvant therapy.


Staging of Pancreatic Ductal Adenocarcinoma. FDG-PET/CT The literature search did not identify any studies that examined the accuracy of FDG-PET/CT in the assessment of staging following neoadjuvant therapy.


Staging of Pancreatic Ductal Adenocarcinoma. Reporting of Imaging Findings for Staging Pancreatic Cancer An emerging issue has been the reporting of findings for staging for pancreatic cancer by radiologists, namely, the usefulness of structured reporting or template reporting versus free-form (nonstructured) dictation. A single institution study had surgeons evaluate 48 structured and 72 nonstructured reports and found that information for surgical planning was readily accessible in 60% to 98% of structured reports, but only 32% to 54% in nonstructured reports [53]. In a retrospective study of 200 reports reviewed by radiologists, it was noted that in 20.3% of reports, resectability status could not be determined based on the report alone [54].


Staging of Pancreatic Ductal Adenocarcinoma. Although there are references that report on studies with design limitations, 16 well-designed or good-quality studies provide good evidence.


Staging of Pancreatic Ductal Adenocarcinoma. Appropriateness Category Names and Definitions Relative Radiation Level Information Potential adverse health effects associated with radiation exposure are an important factor to consider when selecting the appropriate imaging procedure. Because there is a wide range of radiation exposures associated with different diagnostic procedures, a relative radiation level (RRL) indication has been included for each imaging examination. The RRLs are based on effective dose, which is a radiation dose quantity that is used to estimate population total radiation risk associated with an imaging procedure. Patients in the pediatric age group are at inherently higher risk from exposure, both because of organ sensitivity and longer life expectancy (relevant to the long latency that appears to accompany radiation exposure). For these reasons, the RRL dose estimate ranges for pediatric examinations are lower as compared to those specified for adults (see Table below). Additional


Staging of Pancreatic Ductal Adenocarcinoma. Supporting Documents For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Back Pain Child PCAs

Back Pain Child PCAs. Introduction/Background It is now generally accepted that nontraumatic back pain in the pediatric population is common. Evaluation of the spine in the setting of trauma will be addressed with a forthcoming ACR Appropriateness Criteria guideline. Early studies have reported prevalence as low as 2%, with more recent evidence suggesting that up to half of the pediatric population experiences back pain [1]. The incidence of back pain increases throughout childhood, most notably lower back pain [2]. Childhood back pain may be predictive of adult back pain [2]. Female sex, poor general health, high level of activity, backpack loads, and family history of back pain are risk factors that have been suggested [3]. Most pediatric back pain is mechanical and responds to conservative treatment with imaging not required in the clinical evaluation [1,4-6]. However, back pain may be caused by more serious conditions, including the broad categories of traumatic, infectious, inflammatory, congenital, and neoplastic processes [7,8]. Evaluation of scoliosis associated with pain will be addressed under a separate ACR Appropriateness Criteria guideline. Back pain is common in the pediatric athlete, with many potential etiologies [9].


Back Pain Child PCAs

Back Pain Child PCAs. The presence of isolated back pain in a child has previously been an indication for imaging; however, recently a more conservative approach has been suggested. As in adults, a diagnostic algorithm is suggested for evaluation of children with back pain in order to reduce the number of unnecessary examinations performed and resultant radiation exposure [10]. Children with back pain of short duration, a normal physical examination, and minor or no history of trauma will likely benefit little from further laboratory or imaging evaluation [1,8,11]. Imaging should be reserved for the presence of persistent back pain with concerning clinical and laboratory findings. Laboratory evaluation with a complete blood count and sedimentation rate may be of use to evaluate for a systemic etiology [12-14]. Clinical and laboratory findings suggesting an infectious or neoplastic etiology should be imaged without delay. The presence of constant pain, night pain, and radicular pain, alone or in combination, lasting for 4 weeks or more, constitute clinical red flags that should prompt further imaging. An abnormal neurologic examination should prompt immediate imaging [1,4,5].


Back Pain Child PCAs

Back Pain Child PCAs. Overview of Imaging Modalities Radiographs Radiographs of the symptomatic region are a useful initial imaging modality, as they are readily available and may lead to a diagnosis in a significant number of patients [4]. Vertebral alignment, spinal curvature, and disc height can easily be ascertained using radiographs. The presence of spondylolysis, Scheuermann disease, and primary bone tumors may be suggested on radiographs and direct any further imaging [4,15,16]. Oblique views of the lumbar spine have been shown to double the radiation dose delivered without any additional helpful information beyond the standard frontal and lateral views [6,9]. Radiographs are insensitive to paraspinal and intraspinal soft-tissue masses.


Back Pain Child PCAs

Back Pain Child PCAs. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through society representation on expert panels. Participation by representatives from collaborating societies on the expert panel does not necessarily imply individual or society endorsement of the final document.


Back Pain Child PCAs

Back Pain Child PCAs. Reprint requests to: publications@acr.org


Back Pain Child PCAs

Back Pain Child PCAs. Magnetic Resonance Imaging MRI without contrast has been shown to be an effective screening tool in evaluating pediatric patients with certain red-flag clinical presentations [1,5]. In young patients, the MRI examination may need to be performed under sedation. MRI is the only modality that directly visualizes the spinal cord, ligaments, and intervertebral discs. T2- weighted images and fat-suppression techniques are necessary for evaluating for marrow edema and paraspinal pathology. MRI without contrast is often able to determine a cause of mechanical back pain, most commonly spondylolysis, with high sensitivity [22-24]. Recent studies have demonstrated MRI to be more sensitive than computed tomography (CT) and a potential first-line test in the evaluation of spondylolysis [23,24]. Fluid- sensitive and fat-suppressed MRI techniques are able to identify stress reaction (marrow edema) in the pedicles as well as spondylolisthesis, which are the 2 findings that guide management of these patients [22,24]. MRI is optimal for demonstrating degenerative disc pathology, which may be more common in the pediatric population than previously suspected [25,26].


Back Pain Child PCAs

Back Pain Child PCAs. The main advantage of MRI is optimal intraspinal and paraspinal soft-tissue evaluation. Intraspinal tumors can present with back pain and MRI is the indicated imaging modality in this subset of patients [27,28]. Osteomyelitis and epidural and paraspinal infection are well demonstrated on MRI and can guide surgical intervention [13,14,29]. Fat-suppressed T2 and T1 postcontrast MRI sequences such as short tau inversion recovery, Dixon, and fat-suppressed turbo spin echo are necessary for evaluation of suspected infectious or neoplastic disease involving the vertebrae, discs, or paraspinous soft tissues [8].


Back Pain Child PCAs

Back Pain Child PCAs. Computed Tomography CT without contrast provides excellent bone detail. The modality is suboptimal for evaluating the intraspinal contents and the paraspinal soft tissues in comparison with MRI. The ability of CT to reconstruct in multiple planes and perform 3D volume-rendered images is an advantage. CT targeted to the area of interest can be useful in the evaluation of suspected spondylolysis as well as primary bone tumors such as osteoid osteoma, osteoblastoma, and aneurysmal bone cyst [15,27,30]. However, CT does not demonstrate associated marrow edema. Also, intrinsic fluid-fluid levels and associated soft-tissue abnormalities are better demonstrated on MRI. Apophyseal ring fractures are also well evaluated on CT [31]. CT with contrast can be considered when infection and abscess are suspected and MRI is contraindicated or not feasible.


Back Pain Child PCAs

Back Pain Child PCAs. Myelography and Postmyelography Computed Tomography Spine The indication for myelography and postmyelography CT is narrow and limited because of its invasiveness and limited diagnostic yield. Myelography and postmyelography CT can be considered in conditions where intraspinal pathology is suspected and MRI is either contraindicated or will be significantly limited by existing hardware.


Back Pain Child PCAs

Back Pain Child PCAs. Discussion of Imaging Modalities by Variant Variant 1: Child. Back pain with none of the following clinical red flags: constant pain, night pain, radicular pain, pain lasting >4 weeks, abnormal neurologic examination. Initial imaging evaluation. Radiographs There is little evidence that radiographic evaluation of the region of interest in acute uncomplicated back pain without an associated traumatic event is indicated [8,9,11,12].


Back Pain Child PCAs

Back Pain Child PCAs. MRI Spine MRI is not indicated in back pain without clinical red flags present [1,4,5]. If an inflammatory, infectious, or neoplastic process is suggested from initial clinical or laboratory evaluation, MRI without and with contrast of the complete spine is the suggested imaging modality in further imaging evaluation [8,27,28]. If contrast is


Back Pain Child PCAs

Back Pain Child PCAs. administered, precontrast images are helpful to assess enhancement. There is little use for performing an MRI with contrast only.


Back Pain Child PCAs

Back Pain Child PCAs. CT Spine CT is not indicated for evaluation of patients with back pain and no clinical red flags. If an inflammatory, infectious, or neoplastic process is suggested from initial clinical or laboratory evaluation and MRI cannot be obtained, a CT spine with contrast targeted to the area of interest may be indicated. CT spine without and with contrast is not indicated for evaluation of patients with back pain and no red flags.


Back Pain Child PCAs

Back Pain Child PCAs. Bone Scan Whole Body with SPECT or SPECT/CT Complete Spine SPECT bone scan is not indicated for evaluation of patients with back pain and no red flags.


Back Pain Child PCAs

Back Pain Child PCAs. Myelography and Postmyelography CT Spine This examination is not indicated for evaluation of patients with back pain and no red flags.


Back Pain Child PCAs

Back Pain Child PCAs. Variant 2: Child. Back pain with 1 or more of the following clinical red flags: constant pain, night pain, radicular pain, pain lasting >4 weeks, abnormal neurologic examination. Initial imaging evaluation. Radiographs Radiographs of the cervical, thoracic, or lumbar spine are a useful initial diagnostic imaging procedure for evaluation of back pain in children. Radiographs can demonstrate findings that lead to the diagnosis in up to 24% of children [1,4,5]. Anterior-posterior radiographs are typically sufficient, with additional views only adding to the radiation dose without increase in diagnostic yield. Collimation to the area of concern may aid in the diagnosis [6,9]. Pathologic conditions that can be diagnosed on radiographs include spondylolysis, scoliosis, Scheuermann disease, and bone tumors [1,4,5]. In children with back pain and clinical red flags, negative radiographs are not considered adequate to exclude pathology and additional advanced imaging techniques are required [1,5]. Positive radiographs leading to a specific diagnosis may guide therapy without additional imaging or direct further appropriate imaging evaluation [1,4,5].


Back Pain Child PCAs

Back Pain Child PCAs. MRI Spine Noncontrast MRI of the spine targeted to the region of interest is sensitive for the imaging evaluation of soft- tissue and bony abnormalities associated with pediatric back pain, including paraspinous soft-tissue pathology, disc disease, marrow edema, and intraspinal masses [8,24-26,32]. However, radiographs should be the initial imaging evaluation in most cases. MRI of the total spine may be indicated as the initial evaluation of patients with abnormal neurologic findings. Contrast is helpful in the evaluation of back pain in children when there is clinical or laboratory evidence of infection, inflammation, or tumor [8,13,33]. If contrast is administered, precontrast images are helpful to assess enhancement. There is little use for performing an MRI with contrast only.


Back Pain Child PCAs

Back Pain Child PCAs. CT Spine Bone lesions and fractures are well delineated on targeted noncontrast CT [7,15]. However, radiographs should be obtained initially. Although CT with contrast may be helpful when infection or tumor is suspected, MRI without and with contrast is the modality of choice in the evaluation of these patients. CT with contrast should be considered only when MRI is contraindicated or not feasible. CT both without and with contrast is not usually indicated. In the circumstance where there is a need to determine the presence of calcifications, limited noncontrast images could be obtained through the area of interest.


Back Pain Child PCAs

Back Pain Child PCAs. Bone Scan Whole Body with SPECT or SPECT/CT Complete Spine Tc-99m bone scan may be a useful screening tool in children with back pain and no specific neurologic findings on physical examination [4]. However, radiographs should be the initial imaging examination and may direct further evaluation.


Back Pain Child PCAs

Back Pain Child PCAs. Myelography and Postmyelography CT Spine Because of the invasiveness of the procedure, myelography and postmyelography CT of the whole spine are considered in the setting of an abnormal neurologic examination only if MRI is contraindicated or will have significantly limited diagnostic yield because of spinal hardware.


Back Pain Child PCAs

Back Pain Child PCAs. Variant 3: Child. Back pain with 1 or more of the following clinical red flags: constant pain, night pain, radicular pain, pain lasting >4 weeks, abnormal neurologic examination. Negative radiographs. Children with negative radiographs and back pain associated with clinical red flags should undergo additional imaging evaluation.


Back Pain Child PCAs

Back Pain Child PCAs. MRI Spine MRI of the total spine is sensitive for the imaging evaluation of soft-tissue and bony abnormalities associated with pediatric back pain, including paraspinous soft-tissue pathology, disc disease, marrow edema, and intraspinal masses [8,24-26,32]. Nonneoplastic intraspinal etiologies of back pain such as syrinx and meningoceles are well demonstrated using MRI [34,35]. Two large prospective studies have used MRI in an algorithm for evaluation of pediatric back pain in a total of 348 patients [1,5]. These studies found that MRI had high diagnostic accuracy in identifying and delineating the etiology of pediatric back pain. MRI is especially useful in evaluation of children with positive neurologic findings and should be considered the primary imaging modality in this subset of patients. An imaging algorithm has been proposed that includes only MRI in the imaging evaluation of children with positive neurologic findings [4]. Contrast is helpful in the evaluation of back pain in children when there is clinical or laboratory evidence of infection, inflammation, or tumor [8,13,33]. If contrast is administered, precontrast images are helpful to assess enhancement. There is little use for performing an MRI with contrast only. MRI of the spine in the clinical setting of back pain should always be performed with fat-saturated imaging techniques, especially following the administration of contrast.


Back Pain Child PCAs

Back Pain Child PCAs. CT Spine Fractures and bone lesions are well delineated on targeted noncontrast CT [7,15]. CT has been found to be complementary to bone scan in evaluation of spondylolysis [4,30].


Back Pain Child PCAs

Back Pain Child PCAs. CT with contrast can be used when infection or tumor is suspected; however, MRI without and with contrast is the modality of choice in the evaluation of these patients. CT with contrast targeted to the area of interest should be considered only when MRI is contraindicated or not feasible. Performing CT both without and with contrast is not usually indicated. In the circumstance of determining the presence of calcifications, limited images could be obtained through the area of interest.


Back Pain Child PCAs

Back Pain Child PCAs. Bone Scan Whole Body with SPECT or SPECT/CT Complete Spine Tc-99m bone scan may be a useful tool in children with back pain and no specific neurologic findings on physical examination [4]. However, a retrospective study evaluating bone scan as a screening tool found that primary malignancies of the spine were missed in 3 out of 142 patients, although only planar bone scans were obtained in this study [20]. Although bone scan with SPECT can be very sensitive to bone pathology such as spondylolysis [19], potentially significant causes of back pain could be missed using only this modality [8,20]. SPECT/CT is not addressed in this discussion because it is not widely available.


Back Pain Child PCAs


Back Pain Child PCAs

Back Pain Child PCAs. Variant 4: Child. Back pain with 1 or more of the following clinical red flags: constant pain, night pain, radicular pain, pain lasting >4 weeks, abnormal neurologic examination. Positive radiographs. MRI Spine MRI is sensitive for the imaging evaluation of soft-tissue and bony abnormalities associated with pediatric back pain, including paraspinous soft-tissue pathology, disc disease, marrow edema, and intraspinal masses that may be suggested on radiographs of the spine [8,24-26,32]. Two large prospective studies have used MRI in an algorithm for evaluation of pediatric back pain in a total of 348 patients [1,5]. These studies found that MRI had high diagnostic accuracy in identifying and delineating the etiology of pediatric back pain; however, if a specific diagnosis was determined using spine radiographs, MRI was not performed. MRI can confirm and further characterize abnormalities demonstrated on radiographs. MRI is especially useful in evaluation of children with positive neurologic findings.


Back Pain Child PCAs

Back Pain Child PCAs. An imaging algorithm has been proposed that includes only MRI in the imaging evaluation of children with positive neurologic findings [4]. If contrast is administered, precontrast images are helpful to assess enhancement. Findings on spine radiographs such as disc-space narrowing, endplate irregularity, bone destruction, or widening of the spinal canal suggest an inflammatory, infectious, or neoplastic process [7,8]. MRI of the total spine without and with contrast is helpful in the evaluation of back pain in children with clinical or imaging evidence of infection, inflammation, or tumor [8,13,33]. There is little use for performing an MRI with contrast only. MRI of the spine in the clinical setting of back pain should always be performed with fat-saturated imaging techniques, especially following the administration of contrast.


Back Pain Child PCAs

Back Pain Child PCAs. CT Spine Fractures and bone lesions may be suggested on radiographs of the spine. These entities may be better delineated and confirmed on targeted noncontrast CT [7,15]. CT has been found to be complementary to bone scan in evaluation of spondylolysis [4,30]. CT with contrast should be considered only when MRI is contraindicated or not feasible. Performing CT both without and with contrast is not usually indicated. In the circumstance of determining the presence of calcifications, limited noncontrast images could be obtained through the area of interest.


Back Pain Child PCAs

Back Pain Child PCAs. Bone Scan Whole Body with SPECT or SPECT/CT Complete Spine Tc-99m bone scan may be a useful screening tool in children with back pain and no specific neurologic findings on physical examination [4]. Bone scan can confirm the presence of an abnormality suggested on radiographs, and because of the whole-body technique it has the ability to demonstrate additional osseous abnormalities (multifocality) as regions of increased radiotracer uptake [31,36]


Back Pain Child PCAs

Back Pain Child PCAs. Myelography and Postmyelography CT Spine Because of the invasiveness of the procedure, myelography and postmyelography CT of the total spine are considered in the setting of an abnormal neurologic examination only if MRI is contraindicated or will have significantly limited diagnostic yield because of spinal hardware.


Back Pain Child PCAs

Back Pain Child PCAs. Variant 5: Child. Chronic back pain associated with overuse. Mechanical back pain. Radiographs The most common etiology for overuse-related chronic back pain in children is spondylolysis. Radiography of the symptomatic region of the spine is a useful screening tool for spondylolysis, with a sensitivity of 77.6% for anterior-posterior and lateral radiographs [6]. The combination of negative radiographs and a negative clinical examination was reported to have an 0.81 negative predictive value [21]. Additional views did not significantly increase sensitivity [6,9]. Other reports have suggested a lower sensitivity for diagnosing spondylolysis using radiographs as compared to MRI [24]. Other etiologies for chronic back pain, such as apophyseal ring fractures and Scheuermann disease, may be suggested with radiographs alone [31].


Back Pain Child PCAs

Back Pain Child PCAs. MRI Spine MRI can show edema in the region of the pars interarticularis or adjacent pedicle in spondylolysis with negative radiographs and CT. MRI is especially useful in detection of active spondylolysis and has been positively associated with clinical symptomatology [23,24]. Resolution of signal abnormalities suggests a response to therapy and potential prevention of progression to fracture [22,37]. It remains uncertain whether MRI or bone scan with SPECT is preferred in the evaluation of suspected spondylolysis [38]. Abnormalities on MRI such as apophyseal injuries, spondylolysis, and disc disease have been shown to be associated with back pain in the pediatric athlete [39]. MRI can evaluate radiculopathy elicited by both spondylolytic and nonspondylolytic causes and may demonstrate additional etiologies, including apophyseal fractures, intraspinous ligamentous injury, discogenic injury, Scheuermann disease, and compartment syndromes [8,31,40]. If contrast is administered, precontrast images are needed to assess enhancement. MRI of the spine in the clinical setting of back pain should always be performed with fat-saturated imaging techniques. There is little use for performing an MRI with contrast only. Contrast is not indicated in the evaluation of chronic back pain due to suspected mechanical causes.


Back Pain Child PCAs

Back Pain Child PCAs. CT Spine CT is mostly considered an adjunct to other imaging modalities and has a high sensitivity in evaluation of spondylolysis [6]. CT is superior to radiographs in evaluation of spondylolysis, and with radiation dose-reduction techniques, a similar dose can be achieved [41]. CT has been shown to be complementary in the evaluation of pars interarticularis injuries and has the potential to direct further management [30]. Early stress reaction may be missed using CT alone without a bone scan or MRI [23,42]. Ring apophyseal injuries are also well demonstrated on CT [15,31]. CT spine with contrast is not indicated in mechanical back pain.


Back Pain Child PCAs

Back Pain Child PCAs. Bone Scan Whole Body with SPECT or SPECT/CT Complete Spine There have been studies that have shown that bone scan with SPECT is a sensitive imaging technique for the evaluation of suspected spondylolysis at all ages [6,43,44]. Bone scan has been shown to be more sensitive in comparison to MRI for evaluation of active spondylolysis [19]. However, MRI may be able to detect disc pathology and other processes that can mimic or be associated with spondylolysis [32,40]. In chronic spondylolysis with wide separation and smooth margins, the bone scan may be negative [30]. On the other hand, bone scan can demonstrate increased uptake due to a stress reaction while CT reveals no abnormality [42].


Back Pain Child PCAs

Back Pain Child PCAs. Because of the whole-body technique, bone scan can demonstrate additional osseous abnormalities as regions of increased radiotracer uptake [31,36].


Back Pain Child PCAs

Back Pain Child PCAs. Myelography and Postmyelography CT Spine This examination is not indicated in the evaluation of chronic back pain due to suspected mechanical causes and normal neurologic examination.


Back Pain Child PCAs

Back Pain Child PCAs. Variant 6: Child. Back pain associated with suspected inflammation, infection, or malignancy. Radiographs Radiography of the area of clinical interest can be suggestive of inflammatory, infectious, or malignant conditions affecting the spine; however, the modality is insensitive and can easily miss subtle findings [27,28]. Discogenic infections occur in the pediatric population and manifest as mild disc-space narrowing on radiographs [7]. Lytic or sclerotic primary and metastatic tumors may be identified along with evidence of bony destruction, periosteal reaction, or a soft-tissue mass. Subtle pedicular erosion with widening of the interpedicular distance or enlargement of the neural foramina may be secondary findings due to an intraspinal tumor [8].


Back Pain Child PCAs

Back Pain Child PCAs. MRI Spine If inflammation, infection, or malignancy is suspected, MRI without and with contrast of the total spine or region of interest is indicated. A noncontrast examination may be indicated in the presence of renal dysfunction. MRI is generally accepted as the primary imaging modality for the detection and evaluation of intra- and paraspinal masses [27,28]. The ability to localize the mass in relation to adjacent neural structures is a significant advantage over other imaging modalities [8]. Infectious spondyloarthropathies also are best imaged using MRI because of its ability to evaluate for epidural extension of disease and cord compromise [8,13,29]. MRI may also be able to differentiate tuberculous from nontuberculous spondylitis [14]. Additionally, inflammatory arthropathies are well evaluated with MRI [33]. If contrast is administered, precontrast images are needed to assess enhancement. There is little use for performing an MRI with contrast only. MRI of the spine in this clinical setting should always be performed with fat-saturated imaging techniques.


Back Pain Child PCAs

Back Pain Child PCAs. CT Spine CT spine without contrast is not usually indicated in the evaluation of suspected infection or neoplasm. If there is a mass originating in bone, targeted CT may help to characterize the lesion. CT with contrast demonstrates paraspinal abscesses with high sensitivity and guides surgical management [29]. Associated bone destruction, sclerosis, and disc-space narrowing are well delineated, especially with orthogonal reconstructions [7]. Performing CT both without and with contrast is not usually indicated. In the circumstance where there is a need to determine the presence of calcifications, limited noncontrast images could be obtained through the area of interest.


Back Pain Child PCAs

Back Pain Child PCAs. Bone Scan Whole Body with SPECT or SPECT/CT Complete Spine Bone scan will demonstrate primary osseous lesions and reactive changes but will not adequately evaluate paraspinal soft-tissue masses or intraspinal pathology [7,8,20,36].


Back Pain Child PCAs

Back Pain Child PCAs. Although there are references that report on studies with design limitations, 4 well-designed or good-quality studies provide good evidence.


Back Pain Child PCAs

Back Pain Child PCAs. Supporting Documents For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Cerebrovascular Diseases Stroke and Stroke Related Conditions PCAs. Introduction/Background Cerebrovascular diseases encompass a range of varied clinical presentations and disease processes. This document focuses on clinical scenarios related to stroke and intraparenchymal hemorrhage (IPH), stroke-like conditions such as venous sinus thrombosis and arterial vascular dissection, and known vascular stroke-related risk factors such as cervical bruit and carotid stenosis. The clinical variants included in this document describe imaging management early in clinical presentation with acute or recent onset of symptoms, as well as ongoing imaging during management of known stroke and stroke-related conditions in the subacute and chronic phases. The subset of cerebrovascular diseases and presentations are broad and varied; therefore, the introduction and background of each variant will be discussed individually.