Intensive Care Unit Patients

Intensive Care Unit Patients. A study from a university hospital in British Columbia, Canada, evaluated their quality improvement initiative to reduce daily chest radiographs in the ICU. The authors observed that education, reminders of appropriate indications, and computerized decision support were effective in decreasing the number of routine chest radiographs in an ICU by 26%. There were no differences between the periods in age, sex, or severity of illness (Acute Physiology and Chronic Health Evaluation [APACHE] II score) of the patients, number of chest CTs, mechanical ventilator days, length of ICU stay, and ICU or hospital mortality [9].


Intensive Care Unit Patients

Intensive Care Unit Patients. Another study by Tolsma et al [10] with a total of 1,102 consecutive cardiac surgery patients showed that the diagnostic efficacy of chest radiographs for major abnormalities was higher for the postoperative on-demand chest radiographs (n = 301; 27%) than for the routine chest radiographs taken the morning after surgery (n = 801; 73%)


Intensive Care Unit Patients

Intensive Care Unit Patients

Intensive Care Unit Patients. Intensive Care Unit Patients


Intensive Care Unit Patients

Intensive Care Unit Patients. (6.6% versus 2.7%, P = .004). They concluded that defining clear indications for selective chest radiographs after cardiac surgery is effective and seems to be safe. This approach can significantly reduce the total number of chest radiographs performed and increase their efficacy.


Intensive Care Unit Patients

Intensive Care Unit Patients. Current evidence shows that chest radiographs could be forgone after lung resection because on-demand chest radiographs based on clinical monitoring have a better impact on management and have not proved to negatively affect patient outcomes [11].


Intensive Care Unit Patients

Intensive Care Unit Patients. The authors, however, noted that their results question the current use of chest radiograph as the first-line diagnostic modality for critically ill patients with respiratory symptoms as LUS seems to be a good alternative. Larger trials that compare chest radiograph with LUS not only for accuracy but also for effects on outcome, clinical utility, and ease of implementation are needed [5,12].


Intensive Care Unit Patients

Intensive Care Unit Patients. In another study of 253 LUS examinations, patient management was changed directly as a result of information provided by the LUS in 119 out of 253 cases (47%) [3]. In 81 cases, the change in patient management involved invasive interventions (chest tube, bronchoscopy, diagnostic thoracentesis/fluid drainage, continuous venous- venous hemofiltration, abdominal decompression, tracheotomy), and in 38 cases, noninvasive interventions (PEEP in bed position, antibiotics change/titration, recruitment maneuver, diuretics, physiotherapy, change initiation/change). In 21%, the LUS revealed findings not suspected by the primary physician (7 cases of pneumothorax, 9 cases of significant pleural effusion, 9 cases of pneumonia, 16 cases of unilateral atelectasis, and 12 cases of diffuse interstitial syndrome). It was concluded that, thoracic US has similar diagnostic accuracy to CT in pleural effusion, consolidation, and pneumothorax [3].


Intensive Care Unit Patients

Intensive Care Unit Patients. Variant 2: Stable intensive care unit patient. No change in clinical status. Initial imaging. Radiography Chest Portable Unexpected findings on chest radiographs were noted in <6% of the 2,457 daily routine radiographs that were ordered in 754 consecutive ICU patients in a mixed medical-surgical ICU [13].


Intensive Care Unit Patients

Intensive Care Unit Patients. In a cross-sectional study of ICUs in hospitals in Saudi Arabia, the daily routine chest radiograph was performed in almost 96.8% of ICU patients. However, a majority of the clinical staff members (73%) thought that this current daily routine chest radiographs protocol in the ICUs should be replaced with the on-demand chest radiographs policy. They observed that intensivists support the change of the current practice of daily chest radiographs and recommend an on-demand chest radiographs policy likely to be followed in intensive care management [14].


Intensive Care Unit Patients

Intensive Care Unit Patients. In a survey of Dutch intensivists on the current practice of chest radiography in their departments, only 7% of responding ICUs to the survey were currently performing daily routine chest radiographs for all patients, and 61% of the responding ICUs reported never performing chest radiographs on a routine basis. A daily meeting with a radiologist is an established practice in 72% of the responding ICUs and is judged to be important or even essential by those ICUs. The therapeutic efficacy of routine chest radiographs was assumed by intensivists to be between 10% and 20% compared with 10% and 60% for on-demand chest radiographs. Therapeutic efficacy was defined as the percentage of chest radiograph findings that resulted in a subsequent change in patient management. There was a consensus between intensivists to perform a routine chest radiograph after endotracheal intubation, chest tube placement, or central venous catheterization, and for diagnostic workups for pneumonia, acute respiratory distress


Intensive Care Unit Patients

Intensive Care Unit Patients. In a systematic review and meta-analysis by Ganapathy et al [8] and Mets et al [7] in cardiothoracic surgery patients in the ICU and the post-ICU did not observe any negative influence of on-demand chest radiographs on length of stay in the ICU and hospital, and readmission rate. However, Ganapathy et al [8] observed that CIs were wide and harm was not rigorously assessed. Therefore, they concluded that the safety of abandoning routine chest radiographs in patients admitted to the ICU remains uncertain and mandates further investigation.


Intensive Care Unit Patients

Intensive Care Unit Patients. Current evidence shows that routine daily chest radiographs are not necessary after lung resection because daily imaging in nonhypoxic patients is unlikely to lead to clinically impactful changes in care [15] and because on- demand chest radiographs based on clinical monitoring have a better impact on management without negatively affecting patient outcomes [11].


Intensive Care Unit Patients

Intensive Care Unit Patients. In another study of 253 LUS examinations, the management was changed directly as a result of information provided by the LUS in 119 out of 253 cases (47%) [3]. In 81 cases, the change in patient management involved invasive interventions, and in 21% of cases, the LUS revealed findings not suspected by the primary physician such as pneumothorax, significant pleural effusion, pneumonia, unilateral atelectasis, and diffuse interstitial syndrome. It was concluded that thoracic US has similar diagnostic accuracy to CT in pleural effusion, consolidation, and pneumothorax [3].


Intensive Care Unit Patients

Intensive Care Unit Patients. Variant 3: Intensive care unit patient with clinically worsening condition. Initial imaging. Radiography Chest Portable In a survey of Dutch intensivists, there was a consensus between intensivists to perform a routine chest radiograph after endotracheal intubation, chest tube placement, or CVC as well as for diagnostic workups for pneumonia, ARDS, or pneumothorax [6].


Intensive Care Unit Patients

Intensive Care Unit Patients. In a prospective, single-blind study of 192 critically ill patients, each patient received a LUS examination, a bedside chest radiograph, followed by a thoracic CT scan searching for pneumothorax, CT of the chest confirmed the diagnosis of pneumothorax in 36 (18.75%) patients of which 31 were diagnosed by thoracic US and chest radiograph detected only 19 cases. Overall, LUS showed a considerably higher sensitivity than bedside chest radiograph (86.1% versus 52.7%). LUS also showed higher negative predictive values and diagnostic accuracy compared with chest radiograph (96.8% versus 90.1% and 95.3% versus 90.6%, respectively). Chest radiographs had a slightly higher specificity than LUS (99.4% versus 97.4%) as well as higher positive predictive values (95.0% versus 88.6%) [16].


Intensive Care Unit Patients

Intensive Care Unit Patients


Intensive Care Unit Patients

Intensive Care Unit Patients. A meta-analysis showed that the diagnostic accuracy of chest US was higher than supine chest radiographs for detection of pneumothorax. It seems that chest US is superior to chest radiographs in detection of pneumothorax, even after adjusting for possible sources of heterogeneity [5,12,16,17]. LUS is also a valid tool in excluding pneumothoraces after lung biopsy in postlung transplant patients [18].


Intensive Care Unit Patients

Intensive Care Unit Patients. In a multicenter prospective study of 99 patients with suspected ventilator-associated pneumonia, the diagnostic performance of LUS findings of infection with direct microbiologic examination of endotracheal aspirates showed that LUS had a positive predictive value of 86% to 94% [19,20].


Intensive Care Unit Patients

Intensive Care Unit Patients. LUS showed better sensitivity and specificity than chest radiography for the diagnosis of pleural effusion and also helped distinguish between different forms of effusions, guide thoracentesis, and insertion of chest tubes [21]. LUS could also monitor the volume of effusion drained to help decide removal of the drainage [21]. Evaluation of the performance of a rapid cardiothoracic US protocol, which combines echocardiographically derived E/e' and LUS, for diagnosing acute heart failure in patients with undifferentiated dyspnea in an emergency department showed that the rapid cardiothoracic US protocol provided excellent accuracy for diagnosing acute heart failure [22].


Intensive Care Unit Patients

Intensive Care Unit Patients. In a prospective, single-center study in the ICU, pulse oximetry and pulmonary US were found to be useful tools to screen for, or rule out, impaired oxygenation or lung abnormalities consistent with ARDS in underresourced settings in which arterial blood gas testing and chest radiography are not readily available [23].


Intensive Care Unit Patients

Intensive Care Unit Patients. In a prospective, single-center study, combining SpO2/FiO2 with US was found to be a useful tools in screening for, or ruling out, impaired oxygenation or lung abnormalities consistent with ARDS criteria in underresourced settings where arterial blood gas testing and chest radiography are not readily available [23].


Intensive Care Unit Patients

Intensive Care Unit Patients. Variant 4: Intensive care unit patient following support device placement. Initial imaging. Radiography Chest Portable Endotracheal Tube Placement Since 1980, there have been only 9 studies present in the literature [24-32] that evaluate the significance of chest radiography in assessing endotracheal tube placement following insertion. In 5 studies, between 12% and 15% of patients had malpositioned endotracheal tubes, many of which required repositioning. Two studies found 28% and 46% of tubes malpositioned upon insertion, and the single dissenting paper found that only 2% were malpositioned. Two studies compared radiographs with physical examination [24,33]. In both studies, physical examination predicted malpositioned tubes in 3% of patients, whereas the radiographs showed malpositioning in 14% of patients in one study and 28% in the other [24,33]. Kollef et al [34] found that the vast majority of malpositioned tubes were discovered in the first 3 days.


Intensive Care Unit Patients

Intensive Care Unit Patients. Endotracheal tube repositioning based on measurement at the incisors is inaccurate and the magnitude of the intervention does not correlate with the degree of error. Repositioning of endotracheal tubes based on measurements at the incisors should be abandoned; if not abandoned, follow-up chest radiograph images are recommended [35].


Intensive Care Unit Patients

Intensive Care Unit Patients. Routine daily imaging of patients with tracheostomy in an ICU provides little clinical utility, and chest radiographs in this population should be performed selectively based on the patient's clinical status. In one study of 761 chest radiographs, only 18 (2.3%) radiographs revealed new complications [36]. All complications were clinically suspected prior to imaging. Only 5 (0.7%) complications resulted in a management change. The most common management changes were a change in antibiotic regimen (0.3%) and ordering of diuretics (0.3%) [36].


Intensive Care Unit Patients

Intensive Care Unit Patients. Studies evaluating the efficacy of deep learning systems with deep convolutional neural networks were accurate to detect presence versus absence of an endotracheal tube, but deep convolutional neural networks did not perform as well and achieved only reasonable accuracy for differentiating low versus normal positioning of the endotracheal tube [37].


Intensive Care Unit Patients

Intensive Care Unit Patients. Central Venous Catheter Eight studies were reviewed regarding CVC [24-26,28-30,32,34]. The majority came to the same conclusion: chest radiographs following catheter insertion are useful, with approximately 10% of the chest radiographs demonstrating


Intensive Care Unit Patients

Intensive Care Unit Patients. Intensive Care Unit Patients malpositioned catheters. Pneumothoraces were present in only a small percentage of patients. Gray et al [24] separated jugular and subclavian catheters. Complications were twice as common with subclavian catheters (17% versus 8%), although unsuspected complications were infrequent.


Intensive Care Unit Patients

Intensive Care Unit Patients. In a retrospective chart review in a large teaching hospital system, the overall rate of clinically relevant complications detected on chest radiographs following US-guided right internal jugular vein catheterization is exceedingly low. A routine chest radiograph after this common procedure is an unnecessary use of resources and may delay resuscitation of critically ill patients [38].


Intensive Care Unit Patients

Intensive Care Unit Patients. In 200 central line placements for Whipple procedures, 198 lines were placed in the right internal jugular and 2 were placed in the subclavian [39]. No cases of pneumothorax or hemothorax were identified, and 15.3% of CVCs were improperly positioned. Only one (0.5%) of these was deemed clinically significant and repositioned after the chest radiograph was performed. They concluded that routine chest radiographs consume valuable time and resources and rarely affect management. Selection should be guided by clinical factors [39].


Intensive Care Unit Patients

Intensive Care Unit Patients. Swan-Ganz Catheter Previously mentioned studies incorporated the position and potential complications of Swan-Ganz catheter placements shown on chest radiographs obtained immediately postprocedure. The majority of complications, which occur in approximately 10% of catheter insertions, are minor and require catheter repositioning [24,26,29,40]. The pneumothorax rate was approximately 2% [26,40].


Intensive Care Unit Patients

Intensive Care Unit Patients. Central Venous Catheter In a prospective, blinded, observational study of 210 consecutive patients undergoing emergency central venous catheterization, US was compared with chest radiography to verify the correct CVC placement and to identify mechanical complications; there was a high correlation between these two modalities in identifying possible malpositioning of the catheter. However, the less time required to perform US allows earlier use of the catheter for the administration of acute therapies that can be lifesaving for critically ill patients [45].


Intensive Care Unit Patients

Intensive Care Unit Patients. Several studies demonstrated that LUS can reduce CVC insertion-to-use time and improve patient safety [46-48].


Intensive Care Unit Patients

Intensive Care Unit Patients

Intensive Care Unit Patients. Intensive Care Unit Patients


Intensive Care Unit Patients

Intensive Care Unit Patients. However, in another study, contrast-enhanced US detected 11 of the 16 true catheter malpositionings. Contrast- enhanced US showed 2 false right atrium misplacements and 5 falsely correct CVC positions. They concluded that contrast-enhanced US is not a suitable alternative for standard chest radiography in detecting CVC location; however, considering its high sensitivity and acceptable specificity in our study, its usefulness as a triage method for detecting CVC location on a real-time basis in the operating room cannot be ignored [50].


Intensive Care Unit Patients

Intensive Care Unit Patients. A systematic review and meta-analysis to examine the accuracy of bedside US for confirmation of CVC position and exclusion of pneumothorax compared with chest radiography concluded that LUS is faster than radiography at identifying pneumothorax after CVC insertion. When a CVC malposition exists, bedside US will identify 4 out of every 5 earlier than chest radiography [51].


Intensive Care Unit Patients

Intensive Care Unit Patients. Swan-Ganz Catheter There is insufficient data evaluating the placement of pulmonary artery catheter. US may be used to guide insertion of a Swan-Ganz catheter.


Intensive Care Unit Patients

Intensive Care Unit Patients. Nasogastric Tubes A pilot study confirmed the high sensitivity of US in the correct positioning of gastric tube in the adult ICU patient. The US examination seems to be easy and faster when performed by an intensivist with a sonographic training of only 40 hours [52].


Intensive Care Unit Patients

Intensive Care Unit Patients. A study designed to compare the effectiveness of using auscultation, pH measurements of gastric aspirates, and US as physical examination methods to verify nasogastric tube placement in emergency department patients with low consciousness in 47 patients concluded that US is useful for confirming the results of auscultation after nasogastric tube insertion among patients with low consciousness. When US findings suggest that the nasogastric tube placement is not gastric, additional chest radiographs should be performed [53].


Intensive Care Unit Patients

Intensive Care Unit Patients. Variant 5: Intensive care unit patient. Post chest tube or mediastinal tube removal. Initial imaging. Radiography Chest Portable Few studies have been performed to evaluate the efficacy of the initial chest radiograph after the insertion of a chest tube. The 3 available studies show that approximately 10% of tubes are malpositioned [25,28,32].


Intensive Care Unit Patients

Intensive Care Unit Patients. Sepeheripour et al [54] performed a meta-analysis of studies evaluating the utility of standard chest radiographs following chest tube removal. A total of 6 prospective observational and retrospective cohort studies evaluating routine and indication-directed chest radiographs following chest tube removal were reviewed [55-60]. These studies found a low rate of complications, most notably pneumothorax, following chest tube removal, the majority of which were predicted clinically [57,59], and a low rate of tube reinsertion between 0.25% and 4% [56,60].


Intensive Care Unit Patients

Intensive Care Unit Patients. Currently, there is limited literature on the evaluation of US for post chest tube removal.


Intensive Care Unit Patients

Intensive Care Unit Patients. Intensive Care Unit Patients 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.


Intensive Care Unit Patients

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


Intensive Care Unit Patients

Intensive Care Unit Patients


Management of Vertebral Compression Fractures PCAs. Introduction/Background Vertebral compression fractures (VCFs) can be caused by benign clinical conditions such as osteoporosis, metabolic disorders, congenital disorders, infections, and acute trauma or neoplasms. Neoplasms may incorporate primary/secondary bone tumors and myeloma. Painful VCFs may cause a marked decline in physical activity and quality of life, leading to general physical deconditioning with increased psychological distress. This physical deconditioning, in turn, may prompt further complications related to poor inspiratory effort (ie, atelectasis and pneumonia) [1] and venous stasis (ie, deep venous thrombosis and pulmonary embolism) [2]. Successful and timely management of painful VCFs can improve quality of life, increase the likelihood of an independent and productive life, and prevent superimposed medical complications.


Management of Vertebral Compression Fractures PCAs. This document addresses the management of both osteoporotic and pathologic VCFs.


Management of Vertebral Compression Fractures PCAs. Neoplasms causing VCFs include 1) primary benign bone neoplasms, such as hemangioma (aggressive type) or giant cell tumors [11], and tumor-like conditions causing bony and cellular remodeling, such as aneurysmal bone cysts, or Paget disease (osteitis deformans); 2) primary malignant neoplasms including but not limited to multiple myeloma and lymphoma; and 3) metastatic neoplasms [2,12,13]. Because the literature has focused predominantly


Management of Vertebral Compression Fractures PCAs. aThomas Jefferson University Hospital, Philadelphia, Pennsylvania. bResearch Author, Washington University, Saint Louis, Missouri. cMallinckrodt Institute of Radiology Washington University School of Medicine, Saint Louis, Missouri. dFroedtert & The Medical College of Wisconsin, Milwaukee, Wisconsin. ePanel Chair, University of Utah, Salt Lake City, Utah. fPanel Chair, University of Wisconsin, Madison, Wisconsin. gPanel Chair, Mayo Clinic, Jacksonville, Florida. hPanel Vice-Chair, Duke University Medical Center, Durham, North Carolina. iPanel Vice-Chair, Wake Forest University School of Medicine, Winston Salem, North Carolina. jPanel Vice-Chair, Mallinckrodt Institute of Radiology, Saint Louis, Missouri. kDeaconess Hospital, Evansville, Indiana; American College of Emergency Physicians. lUniversity of Washington School of Medicine, Seattle, Washington; Commission on Radiation Oncology. mBrigham & Women's Hospital & Harvard Medical School, Boston, Massachusetts; American Association of Neurological Surgeons/Congress of Neurological Surgeons. nBrigham & Women's Hospital, Boston, Massachusetts; Committee on Emergency Radiology-GSER. oMedical University of South Carolina, Charleston, South Carolina; North American Spine Society. pSunnybrook Health Sciences Centre, Toronto, Ontario, Canada; Commission on Radiation Oncology. qMayo Clinic, Jacksonville, Florida; Commission on Nuclear Medicine and Molecular Imaging. rMallinckrodt Institute of Radiology, Saint Louis, Missouri, Primary care physician. sSpecialty Chair, University of Kentucky, Lexington, Kentucky. tSpecialty Chair, University of Michigan, Ann Arbor, Michigan. uSpecialty Chair, Montefiore Medical Center, Bronx, New York.


Management of Vertebral Compression Fractures PCAs. 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.


Management of Vertebral Compression Fractures PCAs. Reprint requests to: publications@acr.org


Management of Vertebral Compression Fractures PCAs. Vertebral Compression Fractures on VCFs due to metastatic disease, this document focuses on the management of pathological VCFs secondary to metastatic disease. However, it should be noted that treatment can vary depending on tumor type.


Management of Vertebral Compression Fractures PCAs. Special Treatment Considerations VA is a generic term that includes percutaneous VP, balloon-assisted kyphoplasty (BK) [2], and other implantable methods of VA [17-20]. These procedures, the majority of which are described in the lumbar and thoracic spine, are used for the palliation of pain related to VCFs and have been shown to be effective compared to medical management [13,21-23].


Management of Vertebral Compression Fractures PCAs. Minimally invasive percutaneous image-guided techniques for treating spine tumors include newer technologies, such as radiofrequency ablation (RFA) [37], cryoablation, microwave ablation, alcohol ablation, and laser photocoagulation. These modalities provide an alternative or adjunct therapeutic option for treating spinal tumors beyond medical pain management, surgery, radiation therapy (RT), and standard VA. Curative ablation can be applied to treat specific benign or selected cases of malignant oligometastatic spinal tumors. Pain palliation of primary and secondary bone tumors is also possible with ablation (chemical, thermal, mechanical), cavitation (radiofrequency ionization), and consolidation (VP, BK) techniques performed separately or in combination.


Management of Vertebral Compression Fractures PCAs. Discussion of Procedures by Variant Variant 1: New symptomatic vertebral compression fracture (VCF) identified on radiographs. No known malignancy. Next imaging study. The body regions covered in this clinical scenario are the cervical, thoracic, and lumbar spine. These body regions might be evaluated separately or in combination as guided by physical examination findings, patient history, and other available information, including prior imaging.


Management of Vertebral Compression Fractures PCAs. For some authors, focal tenderness upon palpation in correlation with radiographs of the vertebral column is a satisfactory indication for intervention. However, spine radiographs are often nonspecific with respect to the acuity or cause of the vertebral fracture [38].


Management of Vertebral Compression Fractures PCAs. CT Spine Area of Interest CT provides osseous details of axial spine fractures before VA [12,39]. CT permits evaluation of vertebral body height, architecture, and integrity of the posterior cortex and pedicles before VA, which is critical in patients with cortical disruption, posterior cortex osseous retropulsion, and spinal canal compression. Comparison to prior imaging is helpful to determine acuity. Dual-energy CT may show bone marrow edema with reasonably high sensitivity and specificity [40,41] and good concordance to MRI in thoracolumbar VCFs [42]. Intravenous (IV) contrast does not provide additional value in this clinical scenario.


Management of Vertebral Compression Fractures PCAs. Vertebral Compression Fractures CT Myelography Spine Area of Interest CT myelography is not routinely used for evaluating benign VCFs unless the patient has a neurologic deficit with suspected spinal canal compression.


Management of Vertebral Compression Fractures PCAs. MRI Spine Area of Interest MRI may provide valuable information to determine the need for intervention and procedural guidance. The benefits of MRI for preprocedural planning have been reported [43-45]. Minimally deforming fractures that may not be well seen on conventional radiographs may be better detected on preprocedure MRI, mainly if the imaging evaluation is >3 months since the suspected injury or if there is a change in symptoms from the initial workup [43,46]. Fluid- sensitive MRI sequences (short tau inversion recovery or fat-saturated T2-weighted imaging) help detect and differentiate acute/subacute versus chronic fractures, identifying fracture clefts, and differentiating synchronous fractures [46,47]. MRI is also valuable for distinguishing recent from chronic vertebral fractures in patients with multiple vertebral fractures and diffuse back pain, which can at times confound the clinical examination [48,49]. However, vertebral body edema is not a precise measure of compression fracture age because the duration after an osteoporotic compression fracture is often not known with certainty. Bone marrow edema typically resolves within 1 to 3 months [50,51]. IV contrast is not useful because it does not add information in the setting of recent osteoporotic VCF.


Management of Vertebral Compression Fractures PCAs. Bone Scan Whole Body Tc-99m whole-body bone scan (bone scintigraphy) may be helpful to determine the painful vertebrae [52], particularly the causative level [53,54]. Bone scan and MRI have higher concordance with single-level fractures compared with multiple level involvements [55]. When more than one area of increased activity is detected, bone scans may overestimate the number of acute fractures. As such, multiple regions of radiotracer accumulation should be interpreted cautiously [56]. The utilization of bone scans may be based on institutional preference.


Management of Vertebral Compression Fractures PCAs. SPECT or SPECT/CT Spine Area of Interest Single-photon emission computed tomography (SPECT) coupled with CT provides complementary information because sites of abnormal radiopharmaceutical uptake on the spine are of interest. SPECT images can be anatomically localized on the CT, and anatomic abnormalities on CT images can draw attention to subtle areas of SPECT tracer uptake. SPECT/CT has been shown to localize abnormalities in the vertebra more precisely compared with SPECT imaging alone, particularly in complicated cases, such as multiple collapsed vertebrae of different ages [57]. Studies have demonstrated a 63% to 80% agreement between SPECT/CT and MRI in detecting acute VCF [58,59]. Li et al [60] found that SPECT/CT is useful for imaging diagnosis of acute fractures in their study of 46 patients.


Management of Vertebral Compression Fractures PCAs. FDG-PET/CT Skull Base to Mid-Thigh PET using the tracer fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG) combined with morphologic CT imaging can noninvasively localize metabolic activity in areas of spinal infection [61-63]. Vertebral osteomyelitis may present as a compression fracture [64] and may be difficult to distinguish from noninfectious, osteoporotic VCF. Vertebral osteomyelitis may be considered in the setting of severe back pain, persistent unexplained fever, elevated inflammatory markers (ie, erythrocyte sedimentation rate), or bacteremia without a known extravertebral focus of infection, particularly if the patient is immunocompromised. Importantly, acute benign VCFs can be a source of false positive findings due to increased FDG uptake in the acute phase; however, the increased activity should return to normal in 3 months from the fracture date. If there is a failure of increased PET FDG activity in a VCF to return to normal by 3 months, clinical suspicion for malignancy or infection should remain high [65].


Management of Vertebral Compression Fractures PCAs. Variant 2: New symptomatic VCF identified on radiographs. History of malignancy. Next imaging study. The body regions covered in this clinical scenario are the cervical, thoracic, and lumbar spine. These body regions might be evaluated separately or in combination, guided by physical examination findings, patient history, and other available information, including prior imaging.


Management of Vertebral Compression Fractures PCAs. CT Spine Area of Interest CT provides osseous details of axial spine fractures before VA [12,39]. CT permits evaluation of vertebral body height, architecture, and integrity of the posterior cortex and pedicles before VA, which is critical in patients with


Management of Vertebral Compression Fractures PCAs. Vertebral Compression Fractures cortical disruption, posterior cortex osseous retropulsion, epidural extension, and spinal canal compression. Comparison to prior imaging is helpful to determine acuity. The presence of lobulated paraspinal masses with involvement of both vertebral body and posterior elements at the same time favors malignant involvement [66]. Dual-energy CT may show bone marrow edema with reasonably high sensitivity and specificity [40,41] and good concordance to MRI in thoracolumbar VCFs [42]. The presence of intravertebral vacuum phenomenon favors a benign etiology [67]. IV contrast does not provide additional value in this clinical scenario.


Management of Vertebral Compression Fractures PCAs. CT Myelography Spine Area of Interest CT myelography of the spine may be useful in patients in this clinical scenario because it can delineate the degree of thecal sac compression. Myelography is also obtained in patients with previous metal hardware to evaluate epidural disease and to accurately delineate the spinal cord for preirradiation treatment planning.


Management of Vertebral Compression Fractures PCAs. MRI Spine Area of Interest MRI may provide valuable information to differentiate malignant from benign VCFs. Neoplastic VCFs often have a total replacement of the normally high T1 bone marrow signal intensity, resulting in diffuse homogeneous low signal intensity. In osteoporosis, the underlying mechanism leading to fracture is the loss of bone mineral density with preservation of the marrow [68]. Abnormal marrow signal involving the pedicles or other posterior elements is a strong indicator of malignancy in VCFs because tumor spread to the posterior elements typically occurs before tumor-associated structural instability leads to fracture within the vertebral body [65,69]. Although osteoporotic fractures can also have edema in the pedicles related to stress reaction, they infrequently have signal change in the posterior elements [65,69]. Abnormal epidural or paravertebral soft tissue is another imaging finding suggesting a pathologic VCF with convex retropulsion of the posterior cortex [70]. A bilobed appearance in the ventral extradural space is more commonly seen in neoplastic disease, as opposed to nonneoplastic disease, in which there is preservation of the strong attachment of the central sagittal septum [71]. Fluid-sensitive MRI sequences (short tau inversion recovery or fat-saturated T2-weighted imaging) can help detect fracture clefts and identify synchronous fractures [46,47]. IV contrast may yield beneficial information with increased homogenous and heterogenous enhancement patterns seen more in neoplastic fractures with or without associated enhancing paraspinal soft tissues. Enhancement involving the posterior elements raises the suspicion for malignancy further [66]. Diffusion and perfusion imaging are also used to help differentiate benign from malignant compression fractures with low apparent diffusion coefficient values and increased perfusion parameters, suggesting neoplastic over benign involvement [66].


Management of Vertebral Compression Fractures PCAs. Bone Scan Whole Body Tc-99m whole-body bone scan (bone scintigraphy) may be helpful to determine the painful vertebrae [52] and also to evaluate other areas of metastases because of complete skeletal coverage, especially in a patient with a history of malignancy [53,54,58]. Bone scan and MRI have higher concordance with single-level fractures compared with multiple-level involvement [55]. When more than one area of increased activity is detected, bone scans may overestimate the number of acute fractures. As such, multiple regions of radiotracer accumulation should be interpreted cautiously [56]. Osteosclerotic bone metastases can be detected on bone scintigraphy up to 18 months earlier than on radiographs [72]. The utilization of bone scans may be based on institutional preference.


Management of Vertebral Compression Fractures PCAs. SPECT or SPECT/CT Spine Area of Interest SPECT coupled with CT provides complementary information because sites of abnormal radiopharmaceutical uptake on the spine are of interest. SPECT images can be anatomically localized on the CT, and anatomic abnormalities on CT images can draw attention to subtle areas of SPECT tracer uptake. SPECT/CT has been shown to localize abnormalities in the vertebra more precisely compared to SPECT imaging alone, particularly in complicated cases, such as multiple collapsed vertebrae of different ages [57]. Studies have demonstrated a 63% to 80% agreement between SPECT/CT and MRI in detecting acute VCF [58,59]. Bone SPECT/CT can also gauge successful treatment response after VA and adds valuable information for the cause of back pain. [59].


Management of Vertebral Compression Fractures PCAs. FDG-PET/CT Skull Base to Mid-Thigh FDG-PET combined with morphologic CT imaging can noninvasively localize metabolic activity in areas of spinal neoplastic involvement and can differentiate between benign and malignant VCFs, with the caveat that acute osteoporotic fractures can also have a high standardized uptake value on PET/CT imaging. A meta-analysis by Kim et al [73] showed high sensitivity and moderate specificity for the use of FDG-PET/CT to differentiate benign from malignant compression fractures. In a patient with a history of malignancy, PET/CT is routinely included in the paradigm of metastatic disease evaluation workup [61]. Vertebral osteomyelitis may present as a compression fracture [64] and may be difficult to distinguish from noninfectious, osteoporotic VCF. Other potential radiotracers


Vertebral Compression Fractures

Management of Vertebral Compression Fractures PCAs. Vertebral Compression Fractures


Management of Vertebral Compression Fractures PCAs. have been described for the early detection of marrow-based metastases, such as 18F-NaF PET/CT, which indicates areas of increased bone turnover and is generally used in the assessment of primary and secondary osseous malignancies, the evaluation of response to treatment, and the clarification of abnormalities on other imaging modalities or clinical data. However, 18F-NaF PET/CT is a highly sensitive method in evaluating bone metastases (eg, prostate cancer). Still, it can be problematic because of low specificity because the tracer accumulates in degenerative and inflammatory bone diseases. 18F-fluorocholine may be able to differentiate between degenerative and malignant osseous abnormalities because degenerative changes are not choline-avid [74]. Prostate-specific membrane antigen (PSMA)-PET imaging has been approved by the FDA in patients with prostate cancer with radioactive agent binding to prostatic cancer cells.


Management of Vertebral Compression Fractures PCAs. Image-Guided Biopsy Spine Area of Interest Percutaneous biopsy is performed to verify the etiology of VCF, especially if imaging findings are equivocal or the fractured vertebra is the only site of involvement in a patient with known malignancy. Biopsy has been shown to confirm clinical suspicion of neoplastic involvement and also aids in directing future treatment planning [75].


Management of Vertebral Compression Fractures PCAs. Variant 3: New back pain. Previously treated VCF or multiple VCFs. Initial Imaging. The body regions covered in this clinical scenario are the cervical, thoracic, and lumbar spine. These body regions might be evaluated separately or in combination, guided by physical examination findings, patient history, and other available information, including prior imaging.


Management of Vertebral Compression Fractures PCAs. CT Spine Area of Interest CT provides osseous details of axial spine fractures prior to VA [12,39]. CT permits evaluation of vertebral body height, architecture, and integrity of the posterior cortex and pedicles before VA, which is critical in patients with cortical disruption, posterior cortex osseous retropulsion, epidural extension, and spinal canal compression. CT is also the optimal modality to identify cement leakage in paraspinal, epidural, intravascular, or adjacent discal regions [76,77]. CT also depicts the development of adjacent level fracture in a patient with recent augmentation and new back pain [78]. CT is also useful to evaluate the cause of new pain in patients with surgical intervention with hardware placement. This modality can evaluate a patient with new back pain after undergoing treatment of single- or multiple-level VCFs.


Management of Vertebral Compression Fractures PCAs. CT Myelography Spine Area of Interest CT myelography is not routinely used for evaluating benign VCFs unless the patient has a neurologic deficit with suspected spinal canal compression. This modality can also be helpful in patients who have surgical hardware from prior spinal surgical intervention to evaluate the spinal canal at the involved level.


Management of Vertebral Compression Fractures PCAs. MRI Spine Area of Interest Fluid-sensitive MRI sequences (short tau inversion recovery or fat-saturated T2-weighted imaging) help detect new acute adjacent level fractures after VCF treatment. MRI can also show the presence of procedure-related complications that can result in new pain in a treated patient, including epidural or paraspinal hematomas, infection in or around the treated level(s), spinal canal compression, and cord injury/ischemia [79]. A cerebrospinal fluid leak or pseudomeningocele formation is also well depicted with MRI [80]. IV contrast can add information in a posttreatment scan, especially to evaluate for any infection/inflammation in or adjacent to the spinal canal but it should be noted that sometimes a rind of enhancement maybe seen around the bone cement in treated vertebra due to reactionary changes and mild inflammatory response induced by polymethylmethacrylate.


Management of Vertebral Compression Fractures PCAs. Bone Scan Whole Body Tc-99m whole-body bone scan (bone scintigraphy) may be helpful to determine the painful vertebrae [52], particularly the causative level [53,54]. Bone scan and MRI have higher concordance with single-level fractures compared with multiple-level involvement [55]. When more than one area of increased activity is detected, bone scans may overestimate the number of acute fractures. As such, multiple regions of radiotracer accumulation should be interpreted cautiously [56]. The utilization of bone scans may be based on institutional preference.


Management of Vertebral Compression Fractures PCAs. SPECT or SPECT/CT Spine Area of Interest SPECT coupled with CT provides complementary information because sites of abnormal radiopharmaceutical uptake on the spine are of interest. SPECT images can be anatomically localized on the CT, and anatomic abnormalities on CT images can draw attention to subtle areas of SPECT tracer uptake. SPECT/CT has been shown to localize abnormalities in the vertebra more precisely compared with SPECT imaging alone, particularly in complicated cases, such as multiple collapsed vertebrae of different ages [57]. Studies have demonstrated a 63% to


Management of Vertebral Compression Fractures PCAs. Vertebral Compression Fractures 80% agreement between SPECT/CT and MRI in detecting acute VCF [58,59]. SPECT/CT may be useful for imaging diagnosis of acute fractures [60].


Management of Vertebral Compression Fractures PCAs. FDG-PET/CT Skull Base to Mid-Thigh In the postprocedure setting, new pain may be due to infection. FDG-PET combined with morphologic CT imaging can noninvasively localize metabolic activity in areas of spinal infection. Studies on the diagnosis of vertebral osteomyelitis reported a sensitivity and specificity of 83% and 88% for FDG-PET/CT [61-63]. Vertebral osteomyelitis may present as a compression fracture [64] and may be difficult to distinguish from noninfectious, osteoporotic VCF. Vertebral osteomyelitis may be considered in the setting of severe back pain, persistent unexplained fever, elevated inflammatory markers (ie, erythrocyte sedimentation rate), or bacteremia without a known extravertebral focus of infection, particularly if the patient is immunocompromised.


Management of Vertebral Compression Fractures PCAs. Variant 4: Asymptomatic VCF identified on radiographs. History of malignancy. Next imaging study. The body regions covered in this clinical scenario are the cervical, thoracic, and lumbar spine. These body regions might be evaluated separately or in combination, guided by physical examination findings, patient history, and other available information, including prior imaging.


Management of Vertebral Compression Fractures PCAs. Algorithms for patient selection and VCF management have been proposed by multidisciplinary groups that include oncology, surgery, and interventional radiology, based on evidence and expert opinion for managing metastatic spinal disease [81]. Medical therapy, including bisphosphonates for osteoclast inhibition [82-84] and osteoclast regulating agents [85-87], can be used to prevent skeletal-related events.


Management of Vertebral Compression Fractures PCAs. CT Spine Area of Interest CT provides osseous details of axial spine fractures before VA [12,39]. CT permits evaluation of vertebral body height, architecture, and integrity of the posterior cortex and pedicles before VA, which is critical in patients with cortical disruption, posterior cortex osseous retropulsion, epidural extension, and spinal canal compression [12,39]. Comparison to prior imaging is helpful to determine acuity. The presence of lobulated paraspinal masses with involvement of both vertebral body and posterior elements at the same time favors malignant involvement [66]. CT is fast and can be used to evaluate a patient with new back pain after undergoing single- or multiple-level VCFs. Dual-energy CT may show bone marrow edema with reasonably high sensitivity and specificity [40,41] and good concordance to MRI in thoracolumbar VCFs [42]. Performing contrast-enhanced CT does not add much to the information already available.


Management of Vertebral Compression Fractures PCAs. MRI Spine Area of Interest MRI can provide valuable information in the assessment of VCFs in patients with a history of malignancy or atypical clinical features. In addition to detecting metastases localized entirely in the bone marrow cavity, MRI can be used to differentiate benign from malignant fractures, because osteoporotic VCFs can occur in patients with malignancy [66,67,70,88,89]. MRI allows assessment of the degree of thecal sac or spinal cord compression, epidural tumor extension [16], paraspinal tumor extension, presence of other lesions, and lesion vascularity. Intraosseous disease is best delineated on noncontrast MRI sequences (T1-weighted and short tau inversion recovery). Contrast- enhanced MRI is helpful to delineate epidural, foraminal, paraspinal, and intrathecal disease extension, including intramedullary disease, compared to sequences without contrast. It is most beneficial to compare precontrast and postcontrast MRI sequences. With tumor involvement, marrow edema may be difficult to detect on conventional MRI sequences [90]. Diffusion-weighted [88] and MR perfusion techniques [91] may be helpful tools to differentiate benign from pathological fractures and new metastasis from previously treated lesions despite a similar appearance on conventional MRI [92]. MRI is also important for further treatment planning, such as VA, percutaneous ablation, RT (stereotactic body RT [SBRT] or conventional palliative radiation), or systemic chemotherapy [93-96].


Vertebral Compression Fractures


Management of Vertebral Compression Fractures PCAs. CT Myelography Spine Area of Interest Myelography of the spine may be obtained especially to detect epidural tumor extension and spinal cord compression. This modality can also be helpful in patients who have surgical hardware from prior spinal surgical intervention to evaluate the spinal canal at the involved level.


Management of Vertebral Compression Fractures PCAs. Bone Scan Whole Body Tc-99m bone scan (bone scintigraphy) of the whole body is often used for initial detection of metastases as well as the staging of patients with cancer. Hot uptake on a bone scan can persist for 2 years after the fracture [97] and hence is hard to differentiate a subacute from chronic fracture. In patients with osteoporosis, bone scan can show additional fractures in the skeleton and also can be helpful in distinguishing the cause of back pain among fracture, facet joint arthritis, and disc degenerative lesions and can be of help to triage appropriate treatment [98]. Bone scans may be performed based on institutional preference.


Management of Vertebral Compression Fractures PCAs. SPECT or SPECT/CT Spine Area of Interest SPECT/CT has been shown to precisely localize abnormalities in the vertebra, particularly in complicated cases, such as multiple collapsed vertebrae of different ages [57]. However, MRI has a greater sensitivity and specificity for metastasis in specific spine locations [99] and for certain primaries, such as prostate cancer [100].


Management of Vertebral Compression Fractures PCAs. FDG-PET/CT Skull Base to Mid-Thigh FDG-PET/CT may demonstrate localized metabolic activity in a neoplastic VCF and in areas of spinal infection [61-63]. MRI features coupled with clinical symptoms may help discern the etiology of a VCF with increased FDG uptake [101]. A meta-analysis study showed high sensitivity and moderate specificity for FDG-PET/CT to differentiate malignant versus benign VCFs [73]. Other potential radiotracers have been described for the early detection of marrow-based metastases, such as 18F-NaF PET/CT, which indicates areas of increased bone turnover and is generally used in the assessment of primary and secondary osseous malignancies, the evaluation of response to treatment, and the clarification of abnormalities on other imaging modalities or clinical data. However, 18F-NaF PET/CT is a highly sensitive method in evaluating bone metastases (eg, prostate cancer). Still, it can be problematic because of low specificity because the tracer accumulates in degenerative and inflammatory bone diseases. 18F- fluorocholine may be able to differentiate between degenerative and malignant osseous abnormalities because degenerative changes are not choline-avid [74].


Management of Vertebral Compression Fractures PCAs. Image-Guided Biopsy Spine Area of Interest If the imaging features are ambiguous and not definitely in keeping with a pathologic VCF, a biopsy can be performed to verify the etiology. A biopsy of the spine region of interest may be important for staging when isolated spine involvement is the first presentation of metastatic disease. Both fluoroscopy- and CT-guided spine biopsies can be performed with high diagnostic accuracy and few complications [102].


Management of Vertebral Compression Fractures PCAs. Variant 5: Asymptomatic, osteoporotic VCF. Initial treatment. Most patients with VCFs have a gradual improvement in pain over 2 to 12 weeks, with a variable return of function [103,104]. Bone marrow edema associated with acute fractures on MRI typically resolves within 1 to 3 months [50,51].


Management of Vertebral Compression Fractures PCAs. Patients may not be candidates for percutaneous or surgical intervention because of factors related to performance status, pregnancy, infection, or coagulation disorders, among others. Clinical decision-making must account for the overall risk and benefit to the patient.


Management of Vertebral Compression Fractures PCAs. Medical Management Only Medical management is complementary to other therapies and should be offered in all clinical scenarios. The natural history of most healing VCFs is that of gradual improvement in pain over 2 to 12 weeks, with a variable return of function [103,104]. Conservative management includes medical management with or without methods of immobility and is the initial treatment of painful VCFs [36,107,108].


Management of Vertebral Compression Fractures PCAs. Vertebral Compression Fractures Asymptomatic osteoporotic VCFs do not require active management if not associated with focal mechanical pain and if there is no restriction of physical activity due to the fracture. Patients should return for a follow-up evaluation after 2 to 4 weeks of nonsurgical management, and, after a satisfactory result, continued follow-up may be unnecessary. Additional imaging and clinical assessment may be obtained for patients who have recurrence or persistence of symptoms to determine the source of their discomfort. There should be continuous evaluation and treatment for the underlying disorder of osteoporosis to prevent future fractures. Concerning follow-up, most currently available guidelines are restricted to recommendations on pharmacologic treatment for osteoporosis [109].


Management of Vertebral Compression Fractures PCAs. Physical therapy is likely to be useful in patients with VCFs and osteoporosis. Home exercise programs have a more limited evidence base, with some small trials demonstrating pain reduction, improved balance, and improved quality of life. Back extensor strengthening can improve strength and bone density and reduce the risk of future VCFs. Exercise is beneficial for all patients with osteoporosis [110,111].


Management of Vertebral Compression Fractures PCAs. Percutaneous Ablation Spine Percutaneous thermal ablation procedures are reserved for symptomatic spinal metastatic disease [112].


Management of Vertebral Compression Fractures PCAs. Surgical Consultation Surgical intervention is reserved for patients with neurologic deficits, spinal deformity (eg, junctional kyphosis, retropulsion), or spinal instability. Surgical consultation can assist in prescribing and supervising immobilization devices.


Management of Vertebral Compression Fractures PCAs. Radiation Oncology Consultation There is no role for RT in a patient without a cancer diagnosis and a nonpathologic VCF. If cancer is thought to be the cause of a VCF, a biopsy is needed to confirm a cancer diagnosis. RT is reserved for metastatic spinal disease and typically for those spinal metastases causing pain, neurologic compromise, or those asymptomatic lesions with radiologic features suggesting a risk of neurologic compromise or VCF.


Management of Vertebral Compression Fractures PCAs. Variant 6: Symptomatic osteoporotic VCF with bone marrow edema or intravertebral cleft. Initial treatment. Medical Management Only The traditional first-line treatment of painful VCFs has been nonoperative or conservative management [107,108]. Conservative management includes a short period of bed rest followed by gradual mobilization with external orthoses. Because VCFs are flexion-compression injuries, a hyperextension brace is used. These braces may be beneficial for the first few months until the pain resolves [101]. Although younger patients may tolerate bracing well, elderly patients generally do not because of increased pain with bracing, leading to limited activity with more bed rest. Immobility predisposes patients to venous thrombosis and life-threatening complications such as pulmonary embolism [101]. It can also lead to pressure ulcers, pulmonary complications, urinary tract infections, and progressive deconditioning. Medical management is often complementary to other treatment strategies. To reduce pain and thus promote early mobilization with conservative management, appropriate analgesics should be prescribed. Narcotics should be reserved for patients who receive inadequate relief from regular analgesics and have to be used with caution given the associated effects of sedation, nausea, further decrease in physical conditioning, and fall risks. Most patients with osteoporotic VCF have spontaneous resolution of pain, even without medication, in 6 to 8 weeks [103,104,108,113]. Prevention and treatment of osteoporosis are one of the first steps in managing VCFs. Cigarette smoking should be discouraged, and alcohol should only be consumed in moderation. A daily weight-bearing exercise program should be recommended [101].


Vertebral Compression Fractures

Management of Vertebral Compression Fractures PCAs. Vertebral Compression Fractures


Management of Vertebral Compression Fractures PCAs. Percutaneous Vertebral Augmentation VA, in the form of VP and BK, may be offered to patients who have failed conservative therapy for 3 months [34]. However, recent studies have found VA superior to placebo intervention for pain reduction in patients with acute osteoporotic VCF of <6 weeks duration [22].


Management of Vertebral Compression Fractures PCAs. Two randomized controlled trials that reported no statistically significant advantage for VA versus sham therapy raised discussions and controversial editorials, particularly regarding the inclusion criteria and other methodological issues [113,114]. Several studies have shown the benefit of VA versus conservative treatment in acute osteoporotic VCF [23,108,115-117], with benefits persisting through 1 year after intervention. However, others demonstrated that VA procedures might not affect global spinal alignment [118]. A meta-analysis found improvements in pain intensity, vertebral height, sagittal alignment, functional capacity, and quality of life with BK compared with conventional medical management [119]. Multiple other studies demonstrated the benefit of VA for alignment with improvement in pain relief [22,120-122] and respiratory function [89,123,124]. In a multisociety position statement, it was concluded that the VA of osteoporotic VCF is clearly beneficial in the short term and is likely beneficial in the long term [36]. Given the evidence that VA is more effective than prolonged medical treatment in achieving analgesia, improving function in patients with painful VCFs [117,125], and avoiding the complications of narcotic use, the threshold for performing VA has declined. Farrokhi et al [23] showed in a randomized control trial of percutaneous augmentation versus medical management for relief of pain and disability that the VA group had statistically significant improvements in pain and disability scores maintained over 24 months, improved vertebral body height restoration maintained over 36 months, and fewer adjacent level fractures compared to the medical management group.


Management of Vertebral Compression Fractures PCAs. The timing of when VA is useful has been debated. Studies found VA to be superior to placebo intervention for pain reduction in patients with acute osteoporotic VCF of <6 weeks duration [22]. In a study by Syed et al [33], patients with VCFs >12 weeks compared to those patients with VCFs <12 weeks had equivalent benefit, suggesting that the age of the fracture does not independently affect the outcomes of VA. However, Chen et al [21] showed improved pain relief in chronic fractures >3 months treated with VA compared to conservative management at 1 year follow-up.


Management of Vertebral Compression Fractures PCAs. Implant kyphoplasty is being performed more after the Sakos Trial findings supported the use of titanium implantable VA devices as an early treatment option for painful, acute VCFs with excellent risk/benefit profile [126]. Tutton et al [20] in the KAST study (The Kiva safety and effectiveness Trial), a multicentered randomized control trial successfully established that the Kiva system is noninferior to BK based on a composite primary endpoint assessment incorporating pain-, function-, and device-related serious adverse events for the treatment of osteoporotic VCFs.


Management of Vertebral Compression Fractures PCAs. Cianfoni et al [127] demonstrated the use of stent-assisted internal fixation as a minimally invasive option to obtain VA and restore axial load capability in severe osteoporotic fractures, potentially obviating more invasive surgical interventions in situations that would pose significant challenges to standard VA.


Management of Vertebral Compression Fractures PCAs. When the etiology of the VCF is questionable, biopsy may be necessary and can be performed as a part of the VA procedure [128,129].


Management of Vertebral Compression Fractures PCAs. Surgical Consultation Surgical intervention is reserved for patients with neurologic deficits, spinal deformity (eg, junctional kyphosis, retropulsion), or spinal instability. Several surgical techniques have been developed to treat osteoporosis-related deformities, including posterior instrumentation with fusion. However, achieving fixation and fusion in these patients can be difficult secondary to insufficient bone integrity. Augmentation methods to improve pedicle screw fixation have evolved, including instrumentation at multiple levels, bioactive cement augmentation, and fenestrated or expandable pedicle screws, but their impact on clinical outcomes remains unknown. Management of osteoporosis in patients undergoing spine surgery is challenging. Still, with appropriate patient selection, medical optimization, and surgical techniques, these patients can experience pain relief, deformity correction, and improved function [130]. Surgical consultation can assist in prescribing and supervising immobilization devices.


Management of Vertebral Compression Fractures PCAs. When the etiology of the VCF is questionable and not amenable to percutaneous biopsy, an open biopsy may be necessary.


Management of Vertebral Compression Fractures PCAs. Vertebral Compression Fractures Radiation Oncology Consultation There is no role for RT in a patient without a cancer diagnosis and a nonpathologic VCF. If cancer is thought to be the cause of a VCF, a biopsy is needed to confirm a cancer diagnosis. RT is reserved for metastatic spinal disease and typically for those spinal metastases causing pain, neurologic compromise, or those asymptomatic lesions with radiologic features suggesting a risk of neurologic compromise or VCF.


Management of Vertebral Compression Fractures PCAs. Systemic Radionuclide Therapy This procedure is not useful for benign osteoporosis-related compressions fractures.


Management of Vertebral Compression Fractures PCAs. Medical Management Only Medical management is complementary to other therapies and should be offered in all clinical scenarios. Conservative management includes medical management with or without methods of immobility [36,107,108]. If there is failure of medical management with worsening of symptoms to medications or in the setting of spinal deformity or pulmonary dysfunction, other management alternatives should be considered.


Management of Vertebral Compression Fractures PCAs. Patients complaining of significant pain after undergoing a VA must be re-evaluated with radiographs, CT, and MRI scans because the increased pain maybe due to progression of fracture at the same level or development of adjacent level fracture.


Management of Vertebral Compression Fractures PCAs. Percutaneous Vertebral Augmentation A recent meta-analysis from 2017 comprising 1,328 patients found no increased risk for adjacent or remote level vertebral body fracture following augmentation using VP or BK compared with nonsurgical management. Of the randomized control trials discussed in this document, only 2 studies showed a statistically significant difference in the rate of adjacent vertebral fractures in follow-up between the VA and control groups, one favoring VA and the other nonsurgical management. In addition, VP and BK may be protective against further height loss of a fractured vertebra. In the VERTOS IV trial, the risk of further height loss was almost 10 times higher after the sham procedure compared with VA treatment [133,134].


Management of Vertebral Compression Fractures PCAs. Patients with ongoing compression at a previously treated level can undergo a second augmentation, especially if the initial fluid-filled cleft did not completely fill or the cleft enlarges afterward. In several large studies, intravertebral clefts were identified in between 90% and 100% of cases of recurrent fractures in a previously treated level [135,136]. The goal is more uniform filling of the vertebra to decrease the micromotion at the fractured vertebral endplates, which helps in pain palliation. After initial augmentation, the development of a new adjacent level fracture can also be addressed by repeating the procedure for the new fracture level.


Management of Vertebral Compression Fractures PCAs. Percutaneous Ablation Spine Percutaneous thermal ablation procedures are reserved for symptomatic spinal metastatic disease [112].


Management of Vertebral Compression Fractures PCAs. Surgical Consultation Surgery is typically reserved for patients who have developed new neurologic compromise, new spinal instability, or leakage of cement into the spinal epidural space with canal compression and the development of new radicular symptoms. Observational studies suggest that surgical decompression and stabilization improve neurological status from nonambulatory to ambulatory as well as pain relief [137]. Surgical consultation can be performed concurrently with other procedures.


Management of Vertebral Compression Fractures PCAs. Systemic Radionuclide Therapy This procedure is not useful for this clinical scenario.


Management of Vertebral Compression Fractures PCAs. Variant 8: Benign VCF with worsening pain, deformity, or pulmonary dysfunction. Initial treatment. Most VCFs show a gradual improvement in pain over 2 to 12 weeks, with a variable return of function [103,104]. Bone marrow edema associated with acute fractures on MRI typically resolves within 1 to 3 months [50,51].


Management of Vertebral Compression Fractures PCAs. Medical Management Only Medical management is complementary to other therapies and should be offered in all clinical scenarios. Conservative management includes medical management with or without methods of immobility and is the initial treatment of painful VCFs [36,107,108].


Management of Vertebral Compression Fractures PCAs. Patients may not be candidates for percutaneous or surgical intervention because of factors related to performance status, pregnancy, infection, or coagulation disorders, among others. Clinical decision-making must account for the overall risk and benefit to the patient.


Management of Vertebral Compression Fractures PCAs. Percutaneous Vertebral Augmentation VA may be a treatment option [36,107] for osteoporotic VCFs because there is evidence that VA is associated with better pain relief and improved functional outcomes compared to conservative therapy [21,23,32,34]. VA has shown immediate and considerable improvement in pain and patient mobility. This supports consideration of VA to abate the secondary sequelae of VCFs, such as decreased bone mineral density and muscle strength with immobility [138,139], increased risk of deep venous thrombosis [138], and deconditioning of cardiovascular and respiratory muscles [1,139]. Because of improved alignment and decreased pain, VA has been shown to improve pulmonary function in patients with VCF [89,123,124,140]. Certain newer variants of VA are shown to be comparable to standard methods, such as BK, for decreased pain score, functional improvement, and height restoration [17,141].


Management of Vertebral Compression Fractures PCAs. The timing of when VA is useful has been debated. In the VERTOS II trial, of the patients who had significant pain relief on medical management, the majority achieved this level by 3 months; this study suggested that patients who had not received sufficient pain relief by 3 months with conservative treatment may be candidates for VA [34]. Studies have found VA to be superior to placebo intervention for pain reduction in patients with acute osteoporotic VCF of <6 weeks duration [22]. As noted in Variant 1 in the study by Syed et al [33], patients with VCF >12 weeks compared with VCF <12 weeks had equivalent benefit suggesting that the age of the fracture does not independently affect the outcomes of VA, although there is evidence for treatment of subacute and chronic, painful compression fractures [21,23,31,32].


Management of Vertebral Compression Fractures PCAs. Vertebral Compression Fractures position that BK or VP may be considered to be useful and generally interchangeable techniques for the performance of VA [36].


Management of Vertebral Compression Fractures PCAs. Surgical Consultation Surgical intervention is reserved for patients with neurologic deficits or spinal instability. When the etiology of the VCF is questionable and percutaneous biopsy is not feasible, an open biopsy may be necessary. Surgical consultation can assist in prescribing and supervising immobilization devices.


Management of Vertebral Compression Fractures PCAs. Radiation Oncology Consultation There is no role for RT in a patient without a cancer diagnosis and a nonpathologic VCF. If cancer is thought to be the cause of a VCF, then a biopsy is needed to confirm a cancer diagnosis. RT is reserved for metastatic spinal disease and typically for those spinal metastases causing pain, neurologic compromise, or those asymptomatic lesions with radiologic features suggesting a risk of neurologic compromise or VCF.


Management of Vertebral Compression Fractures PCAs. Systemic Radionuclide Therapy This procedure is not useful for this clinical scenario but this therapy maybe an option for pain palliation in patients with multifocal osteoblastic metastases, particularly hormone-resistant prostate and breast cancers. The radionuclides are incorporated into the bony matrix and emit radioactive alpha or beta particles that reduce tumor volume and decrease the production of pain sensitive cytokines


Management of Vertebral Compression Fractures PCAs. Variant 9: Pathological VCF with ongoing or increasing mechanical pain. Initial treatment. Medical Management Only Medical management is complementary to other therapies and should be offered in all clinical scenarios. Upon presentation with neurological deficits, the patient should be treated with corticosteroid therapy, and treatment should be initiated as soon as possible to prevent further neurological deterioration [142].


Management of Vertebral Compression Fractures PCAs. Percutaneous Ablation Spine Image-guided ablative therapies demonstrate potential advantages, including reduced morbidity, lower procedural suitability for real-time imaging guidance, the ability to perform therapy in an outpatient setting, synergy with other cancer treatments, repeatability, and short procedural time [143]. Percutaneous thermal ablation of vertebral metastases is a valid therapeutic option for the following patient subgroups: patients with a life expectancy of more than 6 months, good performance status, and few visceral metastases; uncomplicated (lack of metastatic epidural spinal cord compression), painful spinal metastases; and stable pathologic VCF. Percutaneous thermal ablation has been demonstrated to be an effective treatment option for the management of vertebral metastases with an excellent safety profile. The local tumor control rates of percutaneous thermal ablation of spinal osseous metastatic disease have been reported at 70% to 96% in several case series [144-146]. Implementation of appropriate patient selection guidelines, the optimal choice of ablation modality, and the use of thermal protection when necessary are major contributors to improved treatment outcomes.


Management of Vertebral Compression Fractures PCAs. RFA is typically used to treat osteolytic or mixed osteolytic-osteoblastic vertebral (body and/or posterior elements) tumors without soft tissue components. RFA is often ineffective in treating primarily osteoblastic lesions because of the high impedance of densely sclerotic bone [145].


Management of Vertebral Compression Fractures PCAs. Microwave ablation uses electromagnetic waves to agitate water molecules, producing friction and heat that induces cellular death via coagulation necrosis. Microwave ablation is more effective in high-impedance tissues like bone because poor thermal conduction in bone may be at times a limiting factor in RFA. Osseous relative permeability and low conduction help microwaves penetrate deeper and are more effective in thermal ablation than RFA. Microwave ablation is a promising, safe, and effective treatment for osseous tumors, resulting in both a reduction in pain and a degree of locoregional control of the disease process [143].


Management of Vertebral Compression Fractures PCAs. Cryoablation results in the formation of a hypoattenuating ice ball, which is readily identified by CT, beyond which tissues are safe from thermal injury. Additional advantages of cryoablation are decreased intraprocedural and postprocedural pain, the ability to use multiple probes in various orientations to achieve additive overlapping ablation zones, and efficiency in treating osteoblastic metastases [147]. Typically followed VA procedure patients should still be considered for radiation.


Management of Vertebral Compression Fractures PCAs. Vertebral Compression Fractures Percutaneous Vertebral Augmentation VA is a safe and effective treatment for vertebrae weakened by neoplasia [148]. VA provides analgesia and structural reinforcement more rapidly than other treatment measures [149]. Certain newer variants of VA have been shown to be comparable to standard methods, such as BK, in decreasing pain scores and functional improvement [17]. VCFs following SBRT are also amenable to VA. Typically followed VA procedure patients should still be considered for radiation.


Management of Vertebral Compression Fractures PCAs. Surgical Consultation Surgery is the standard of care for pathologic VCF complicated by frank spinal instability and/or neurologic deficits. The SINS can be used to categorize the metastatic spinal segment as stable, potentially unstable, or unstable based on anatomic and clinical factors [150] and can guide surgical referral [14,150]. In the setting of metastatic spinal cord compression, mainly because of osseous compression, surgery is more likely to allow recovery compared to RT alone [151]. Observational studies suggest that surgical decompression, tumor excision, and stabilization improve neurological status from nonambulatory to ambulatory and provide pain relief [137]. Decompressive surgery followed by RT may benefit symptomatic spinal cord compression in patients who are <65 years of age, in the setting of a single level of compression, in patients with neurologic deficits for <48 hours, and in those patients with a predicted survival of at least 3 months [152]. The combination of a spine stabilization procedure and RT may also help manage axial pain and aid in neurologic recovery [153].


Management of Vertebral Compression Fractures PCAs. A large prospective randomized trial shows that patients with metastatic epidural spinal cord compression treated with direct decompressive surgery plus postoperative radiotherapy retain the ability to walk for longer and regain the ability more often than patients treated with radiotherapy alone. Surgery allows most patients to remain ambulatory for the remainder of their lives, whereas patients treated with radiation alone spend a substantial proportion of their remaining time paraplegic. Surgical treatment also results in increased survival time. The better survival time in the surgical group was probably because a greater proportion of patients in this group were ambulatory and remained so for longer than those in the radiation group. Therefore, patients in the surgery group were less susceptible to infections, blood clots, and other problems that result in the death of paraplegic patients. Surgical treatment also reduces the need for corticosteroids and opioid pain relief [154]. Palliative surgery using posterior decompression and fixation combined with intraoperative VA to treat spinal metastases with osseous and epidural disease can improve neurological function, alleviate pain effectively, and allow low cement leakage and timely disposal of leakage if it happens [155].


Management of Vertebral Compression Fractures PCAs. Radiation Oncology Consultation The current standard of care for the management of diffuse painful osseous metastases is external beam RT [156] for at least partial pain palliation [157]. A short course, such as 8 Gy in 1 fraction (as opposed to 20 Gy in 5 fractions or 30 Gy in 10 fractions), is best for patients who have radiosensitive tumors (hematologic primary, seminoma, small-cell lung cancer) or have a poor survival prognosis (<3 months). Some studies have demonstrated benefit in up to 70% of patients treated with respect to neurologic improvement for patients with symptomatic spinal cord compression [158,159]. Advancements in radiotherapy have allowed for the delivery of high precision dose- escalated treatment, known as SBRT, to targets throughout the body with excellent local control rates. Recently, the first phase II randomized trial comparing conventional radiotherapy to comprehensive SBRT of oligometastatic disease demonstrated an overall survival and progression-free survival advantage [160]. The spine is a common site of metastasis and a complex site for SBRT given the adjacent spinal cord and the tumor embedded within the bone tissue putting the patient at risk of fracture [161]. SBRT delivers precise, high-dose radiation to the target region while sparing the spinal cord and provides satisfactory efficacy and an acceptable safety profile for spinal metastases. A recent landmark randomized phase 3 trial led by Sahgal et al [162] showed that SBRT delivering 24 Gy in 2 fractions was superior to conventional radiotherapy delivering 20 Gy in 5 fractions for patients with limited painful spinal metastases. They reported an 11% risk of VCF in the SBRT arm and superior complete response rates for pain at 3 and 6 months posttreatment with SBRT [162].


Management of Vertebral Compression Fractures PCAs. No comparative randomized trials have been performed to establish optimal dosing of spine SBRT. Single-fraction SBRT may result in a higher local control rate than those of the other fractionations, particularly with 24 Gy in 1 fraction. However, high-dose single fraction SBRT comes at the expense of a greater rate of vertebral fracture, which can even approximate 40% [96]. At present, the dose of spine SBRT varies from 18 to 24 Gy in 1 fraction, 24 Gy in 2 fractions, and 24 to 40 Gy in 3 to 5 fractions [95]. A study by Chen et al [163] using normal tissue complication probability modeling suggests that the larger volume of the vertebral segment receiving lower doses is more closely associated with post-SBRT VCF than high dose regions, and technical developments in spine SBRT


Management of Vertebral Compression Fractures PCAs. Vertebral Compression Fractures continue to evolve with respect to mitigating the risk of iatrogenic fracture. Typically VCF secondary to radiation can be managed with a cement augmentation procedure, and there is increasing use of cement augmentation procedures prophylactically to mitigate the risk of iatrogenic VCF [15,164]. Postoperative SBRT has also been increasingly used with promising results [165] and should be considered in selected patients to optimize local tumor control.


Management of Vertebral Compression Fractures PCAs. Vertebral Compression Fractures 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.


Management of Vertebral Compression Fractures PCAs. For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Movement Disorders and Neurodegenerative Diseases. Introduction/Background Movement disorders and neurodegenerative diseases are a variety of conditions that involve progressive neuronal degeneration, injury, or death and may involve the cortex, deep gray nuclei, subcortical white matter, brainstem, cerebellum, and spinal cord, along with connections to associated motor pathways in the cortex or extrapyramidal system. Movement disorders can present as either hypokinetic disorders, which include the Parkinsonian syndromes (idiopathic and atypical), or hyperkinetic disorders, which include Huntington disease (HD), prion disease, and neurodegeneration with brain iron accumulation (NBIA). Motor neuron diseases are a related group of syndromes that involve degeneration of upper or lower motor neurons. Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease and is characterized by degeneration of both the upper and lower motor neurons.


Movement Disorders and Neurodegenerative Diseases. Establishing the correct diagnosis of a movement disorder or neurodegenerative process can be difficult because of the variable and complex features of these conditions, the unusual clinical presentations of some of these patients, and the overlapping symptoms and characteristics. A combination of imaging techniques is often needed for complete evaluation of the patient and to help establish the most likely diagnosis. Initial assessment using structural imaging, with MRI preferred over CT, is helpful not only to look for patterns of atrophy, parenchymal abnormality, or abnormal substance deposition but also to exclude other potential etiologies, including underlying structural or vascular lesions, autoimmune or infectious processes, drug or medication toxicity, or hydrocephalus. More advanced MRI techniques, including diffusion tensor imaging, magnetization transfer ratio imaging, and postprocessing techniques such as quantitative volumetric analysis, may be useful in the evaluation of the microstructural makeup of the brain parenchyma, including the integrity of gray matter, white matter, and their connecting neural pathways. Nuclear medicine studies can be used to evaluate for abnormal patterns of glucose metabolism, buildup of abnormal particles or proteins within neurons, dysfunction or loss of specific categories of neurons, or individual neurochemical deficits.


Movement Disorders and Neurodegenerative Diseases. Discussion of Procedures by Variant Variant 1: Rapidly progressive dementia; suspected Creutzfeldt-Jakob disease. Initial imaging. Rapidly progressive dementias (RPDs) are a group of conditions that result in onset of dementia over weeks or months. Although prion diseases, such as Creutzfeldt-Jakob disease (CJD), are the prototypical example of RPD, the differential diagnosis of RPD is robust, including both reversible and irreversible causes. For instance, a study out of the Memory and Aging Center at the University of California, San Francisco, showed that the diagnostic breakdown of RPDs in their patient population was 62% prion disease (all forms), 15% other neurodegenerative diseases, 8% autoimmune, 4% infectious, 2% psychiatric, 2% cancer, 2% toxic-metabolic, 2% vascular, and 4% of undetermined etiology, often representing leukoencephalopathies [1]. Importantly, 17% of their patients had potentially treatable etiologies (50% autoimmune, 13% infectious, 13% psychiatric, 13% cancer, and 10% toxic- metabolic).


Movement Disorders and Neurodegenerative Diseases. aMassachusetts General Hospital, Boston, Massachusetts. bResearch Author, Massachusetts General Hospital, Boston, cUT Southwestern Medical Center, Dallas, Texas. Massachusetts. dPanel Chair, Montefiore Medical Center, Bronx, New York. eUC San Diego Health, San Diego, California. fOttawa Hospital Research Institute and the Department of Radiology, The University of Ottawa, Ottawa, Ontario, Canada; Canadian Association of Radiologists. gUniversity of Kansas Medical Center, Kansas City, Kansas. hEinstein Healthcare Network, Philadelphia, Pennsylvania. iUniversity of California San Diego Medical Center, San Diego, California. jOregon Health & Science University, Portland, Oregon. kUniversity of North Carolina School of Medicine, Chapel Hill, North Carolina; American Academy of Neurology. lNorthwestern University Feinberg School of Medicine, Chicago, Neurosurgery Expert. mWalter Reed National Military Medical Center, Bethesda, Maryland. nUIC Medical Center, Chicago, Illinois; Neurosurgery Expert. oColumbia University Medical Center, New York, New York. pSpecialty Chair, Atlanta VA Health Care System and Emory University, Atlanta, Georgia.


Movement Disorders and Neurodegenerative Diseases. 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.


Movement Disorders and Neurodegenerative Diseases. Reprint requests to: publications@acr.org


Movement Disorders and Neurodegenerative Diseases. Movement Disorders and Neurodegenerative Diseases Human prion diseases, also known as transmissible spongiform encephalopathies, represent the most common cause of RPD and are a group of uniformly fatal neurodegenerative disorders associated with accumulation of a misfolded form of the normal prion protein. CJD is the most common human transmissible spongiform encephalopathy and can be either infectious or neurogenetic in nature. Four distinct types are currently recognized: sporadic, familial/genetic (mutations of the prion protein gene), iatrogenic, and variant. Sporadic is the most common type, comprising approximately 85% of the cases, with an annual incidence of 1 to 2 cases/million and peak age of onset from 55 to 75 years [2]. The most common clinical course of sporadic CJD is rapidly worsening dementia, which may be followed by myoclonic jerks and akinetic mutism. Sporadic CJD has a median survival of approximately 5 months [2]. The diagnosis of CJD is multifactorial and includes clinical history, physical examination, electroencephalography, diagnostic imaging, cerebrospinal fluid analysis for real-time quaking-induced conversion (CSF RT-QuIC), 14-3-3, and tau proteins, and PRNP gene sequencing [3].


Movement Disorders and Neurodegenerative Diseases. FDG-PET/CT Brain PET using the tracer fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG) may be helpful in the evaluation of a patient with suspected CJD. FDG-PET/CT demonstrates widespread cerebral hypometabolism, even early on in the disease process, which has been noted to correspond with histopathological astrocytosis, neuronal death, and spongiform changes [4,5]. However, the lack of specificity of the findings limit its utility as the initial imaging study.


Movement Disorders and Neurodegenerative Diseases. MR Spectroscopy Head Although not indicated as the initial imaging study, MR spectroscopy of the brain may be helpful in providing additional information for more atypical cases of CJD. MR spectroscopy has shown decreased absolute levels of N- acetyl aspartate and ratios of N-acetyl aspartate to other metabolites in a pattern similar to the signal abnormalities seen on T2-weighted and diffusion-weighted imaging, particularly later in the disease course [6,7].


Movement Disorders and Neurodegenerative Diseases. MRI Functional (fMRI) Head There is no relevant literature for functional MRI (fMRI) of the brain in the initial imaging evaluation of a patient with RPD or suspected CJD.


Movement Disorders and Neurodegenerative Diseases. MRI Head In patients with RPD or suspected prion disease, MRI of the brain is the optimal imaging modality, with the most sensitive sequences being diffusion weighted and T2-fluid-attenuated inversion recovery (FLAIR) [8,9]. Although intravenous (IV) contrast is not specifically needed for the diagnosis of CJD, use of IV contrast can provide important diagnostic information for identifying other known causes of RPD, most notably including autoimmune and inflammatory etiologies.


Movement Disorders and Neurodegenerative Diseases. HMPAO SPECT or SPECT/CT Brain Tc-99m hexamethyl-propylamine-oxime (HMPAO) single-photon emission computed tomography (SPECT)/CT of the brain may be helpful in the evaluation of a patient with suspected CJD. Tc-99m HMPAO SPECT/CT demonstrates changes in regional cerebral blood flow that can be seen even before signal changes are apparent on MRI [18,19]. Despite the increased sensitivity for early changes, the lack of specificity of the SPECT findings limits its utility as the initial imaging study.


Movement Disorders and Neurodegenerative Diseases. Movement Disorders and Neurodegenerative Diseases Variant 2: Chorea; suspected Huntington disease. Initial imaging. Chorea is characterized by involuntary, flowing, nonstereotyped movements that often possess a writhing quality. HD is the prototypical choreiform disorder and the most common cause of chorea in adults. However, the differential diagnosis of chorea includes a number of additional genetic and neurodegenerative disorders in addition to myriad acquired conditions, such as cerebrovascular, infectious, autoimmune, metabolic, neurodegenerative, and drug-induced syndromes. As such, the diagnostic workup, although often focused on HD, must nonetheless consider these other potential etiologies.


Movement Disorders and Neurodegenerative Diseases. HD is a hereditary, autosomal dominant fatal neurodegenerative disorder with complete penetrance characterized by progressive behavioral symptoms, choreoathetosis and/or rigidity, and cognitive dysfunction. The genetic basis of the disease is an abnormally increased number of CAG repeats in the huntingtin gene on the short arm of chromosome 4 (more than 38 repeats used to confirm the diagnosis), often with progressive increase in the length of the repeating sequences in successive generations, resulting in symptoms earlier in life (anticipation). The incidence is ~10/100,000, with average age of onset between 35 to 45 years and symptom progression until death within 15 to 20 years of onset [20]. Abnormal aggregates of the huntingtin protein accumulate in the brain and impair the function of a variety of transcription factors, ultimately leading to the loss of GABAergic medium spiny neurons, particularly in the striatum and cortex [20]. Genetic testing to determine the CAG repeat number for each allele is commercially available and the diagnostic test of choice. Patients with suspected HD should undergo genetic counseling and testing to exclude or confirm HD in concert with initial imaging, given that imaging may be normal early on in the disease course.


Movement Disorders and Neurodegenerative Diseases. CT Head CT is not the preferred imaging modality for suspected HD because of its limited soft-tissue characterization when compared with MRI. However, CT may be useful for excluding other etiologies of chorea, such as cerebrovascular disease or acute infectious or inflammatory processes. Contrast is typically not indicated when CT of the head is being utilized in the initial evaluation of chorea. As with MRI, CT imaging may be normal early in HD, with the progressive and disproportionate volume loss of the neostriatum only becoming apparent on later imaging studies.


Movement Disorders and Neurodegenerative Diseases. FDG-PET/CT Brain There is insufficient evidence to support the use of FDG-PET/CT of the brain in the initial evaluation of a patient with chorea or suspected HD. Among known HD gene carriers, FDG-PET may help demonstrate early neostriatal dysfunction (manifested as hypometabolism), which can precede neuronal loss detectable on structural imaging [21]. Note that FDG hypometabolism has also been noted to involve the frontal and temporal lobe cortices in both HD patients and asymptomatic carriers [21].


Movement Disorders and Neurodegenerative Diseases. MR Spectroscopy Head There is no relevant literature to support the use of MR spectroscopy of the brain in the initial imaging evaluation of a patient with chorea or suspected HD.


Movement Disorders and Neurodegenerative Diseases. MRI Functional (fMRI) Head There is no relevant literature to support the use of fMRI of the brain in the initial imaging evaluation of a patient with chorea or suspected HD.


Movement Disorders and Neurodegenerative Diseases. MRI Head MRI of the brain without IV contrast is the optimal imaging modality in patients with chorea or suspected HD, although it is often normal early on in the disease course of HD. Although often unnecessary, IV contrast may offer limited utility in certain circumstances when infectious or inflammatory conditions are among the differential diagnoses being considered.


Movement Disorders and Neurodegenerative Diseases. MRI findings of HD include progressive marked degeneration and atrophy of the neostriatum, particularly the head of the caudate nuclei (with enlargement of the frontal horns of the lateral ventricles), with associated abnormal signal (either T2 hyperintensity or hypointensity) [22-26]. Additionally, abnormal T2 hyperintensity may be seen in the putamen and can help to highlight more subtle changes of atrophy [22-25]. Although disproportionate volume loss of the neostriatum is the hallmark of HD, voxel-based morphometry has shown that patients with symptomatic and asymptomatic HD have significant reduction in volume in almost all brain structures when compared with normal age-matched controls [27,28].


Movement Disorders and Neurodegenerative Diseases. Movement Disorders and Neurodegenerative Diseases HMPAO SPECT or SPECT/CT Brain There is insufficient evidence to support the use of Tc-99m HMPAO SPECT/CT of the brain in the initial evaluation of a patient with chorea or suspected HD.


Movement Disorders and Neurodegenerative Diseases. Variant 3: Parkinsonian syndromes. Initial imaging. Parkinsonian syndromes are a group of movement disorders characterized by motor symptoms of tremor, rigidity, postural instability, and bradykinesia. Parkinson disease (PD) is the most common cause of Parkinsonism, with other common causes, including progressive supranuclear palsy (PSP), multiple system atrophy (MSA), corticobasal degeneration (CBD), and vascular Parkinsonism, with a number of rarer conditions also within the differential.


Movement Disorders and Neurodegenerative Diseases. PD is a neurodegenerative disease and movement disorder characterized by progressive degeneration of the dopaminergic neurons in the substantia nigra/striatum. It is the most common Parkinsonism syndrome, with an annual incidence estimated at 10 to 18/100,000 in the total population and peak age of onset between 60 to 70 years [29]. PD, also known as idiopathic Parkinsonism, is a synucleinopathy with neuronal deposits of Lewy bodies (predominantly composed of alpha-synuclein and ubiquitin). Initially, Lewy body deposition is seen involving the medulla oblongata, pontine tegmentum, and olfactory system, with later involvement of the substantia nigra and other deep gray nuclei (corresponding to the onset of clinical symptoms), and finally with deposition of Lewy bodies in the cortex.


Movement Disorders and Neurodegenerative Diseases. The clinical presentation of PD is characterized by resting tremor, bradykinesia, and rigidity and is related to progressive degeneration of the dopaminergic neurons in the substantia nigra projecting to the striatum. The estimated interval between initial loss of dopaminergic neurons and the appearance of symptoms is approximately 5 years (after approximately 40% to 50% of the dopaminergic neurons in the substantia nigra have been lost) [29]. Other features include autonomic dysfunction, behavioral changes, and dementia.


Movement Disorders and Neurodegenerative Diseases. MSA can be subdivided into three distinct clinical subtypes: MSA-P (striatonigral degeneration), in which extrapyramidal/parkinsonian features predominate, MSA-C (olivopontocerebellar atrophy), in which ataxia and cerebellar symptoms predominate, and less commonly, MSA-A (Shy-Drager syndrome), in which autonomic dysfunction predominates. The majority of cases of MSA exhibit Parkinsonian symptoms at some stage of the disease, with cerebellar ataxia, pyramidal signs, and dysautonomia (including urinary incontinence) frequently reported. The typical onset is 55 to 65 years of age with a mean disease duration of almost 6 years [30].


Movement Disorders and Neurodegenerative Diseases. PSP, also known as Steele-Richardson-Olszewski syndrome, is the most common atypical Parkinsonism with a prevalence of around 5/100,000 [30]. Patients classically present in the sixth or seventh decade (mean age of onset at 63) with a lurching gait and axial dystonia, manifested as unexplained falls [30]. Ocular symptoms, including blurred vision and slow saccades, can be seen early in the disease; however, the classic finding of vertical supranuclear gaze palsy is usually only seen later in the course of the disease.


Movement Disorders and Neurodegenerative Diseases. Correctly diagnosing a Parkinsonian syndrome on clinical features alone can be quite challenging, and imaging remains an essential diagnostic tool in the evaluation of a patient presenting with Parkinsonian symptoms.


Movement Disorders and Neurodegenerative Diseases. CT Head CT is not the preferred imaging modality for the workup of Parkinsonian syndromes because of its limited soft- tissue characterization when compared with MRI. Nonetheless, CT imaging can effectively demonstrate the patterns of regional volume loss characteristic of MSA, CBD, or PSP, as described in the MRI section. CT findings are


Movement Disorders and Neurodegenerative Diseases. Movement Disorders and Neurodegenerative Diseases nonspecific for PD but can help to exclude focal or regional atrophy, underlying structural lesions, or vascular disease that might signal an alternative diagnosis. Contrast is typically not indicated.


Movement Disorders and Neurodegenerative Diseases. Amyloid PET/CT Brain There is no relevant literature to support the use of amyloid PET/CT in the initial imaging evaluation of a patient with Parkinsonian syndrome.


Movement Disorders and Neurodegenerative Diseases. FDG-PET/CT Brain Despite widespread use of FDG-PET/CT in clinical practice and extensive research, there is still very limited good- quality evidence for the use of FDG-PET/CT in Parkinsonian syndromes. FDG-PET is useful for discriminating PSP from idiopathic PD on the presence of a typical metabolic pattern for PSP, which is not present in PD. PSP is characterized by hypometabolism in the medial frontal and anterior cingulated cortices, striatum, and midbrain. FDG-PET may therefore be useful in early stages of the disease when the clinical diagnosis is less certain. In PD- related cognitive decline, FDG-PET have a typical pattern of hypometabolism mainly affecting the posterior cortical areas [31].