Workup of Pleural Effusion or Pleural Disease. CT Chest Without IV Contrast There is no relevant literature to support the use of CT chest without IV contrast in the initial imaging of recent pneumonia with suspected parapneumonic effusion or empyema. If a noncontrast CT is obtained, 4 out of 5 chest CT findings most commonly associated with the diagnosis of empyema in a recent meta-analysis may be ascertained without IV contrast: pleural thickening (sensitivity 68%, 95% CI, 56%-77%; specificity 87%; 95% CI, 80%-92%), loculation (sensitivity 52%, 95% CI, 44%-59%; specificity 89%; 95% CI, 82%-94%), fat thickening (sensitivity 53%, 95% CI, 47%-60%; specificity 91%; 95% CI, 82%-96%), and fat stranding (sensitivity 39%, 95% CI, 32%- 48%; specificity 97%; 95% CI, 94%-98%) [14]. Of note, these pooled sensitivities and specificities include CT chest with IV contrast or CT chest without IV contrast. Gas in the pleural space is another specific marker for complicated parapneumonic effusion, with specificities ranging from 81% (95% CI, 73%-87%) to 96% (95% CI, 86%-99%) [16,17]. Parapneumonic effusions <2.5 cm in AP dimension can often be managed without thoracentesis [18].


Workup of Pleural Effusion or Pleural Disease. CTA Chest With IV Contrast There is no relevant literature to support the use of CTA chest with IV contrast in the initial imaging of recent pneumonia with suspected parapneumonic effusion or empyema. Note that CTA often employs contrast timing that is earlier than 60 seconds and therefore does not allow sufficient time for pleural enhancement.


Workup of Pleural Effusion or Pleural Disease. MRI Chest Without and With IV Contrast There is no relevant literature to support the use of MRI chest without and with IV contrast in the initial imaging of recent pneumonia with suspected parapneumonic effusion or empyema in adults. In case reports, MRI chest without and with IV contrast has been used as an adjunctive modality for the diagnosis of empyema necessitans [21]. In pediatric patients, limited data suggests MRI is noninferior to CT chest with IV contrast for the diagnosis of empyema [22-24].


Workup of Pleural Effusion or Pleural Disease. MRI Chest Without IV Contrast There is no relevant literature to support the use of MRI chest without IV contrast in the initial imaging of recent pneumonia with suspected parapneumonic effusion or empyema. In small studies, diffusion weighted imaging [25]


Workup of Pleural Effusion or Pleural Disease. Workup of Pleural Effusion or Pleural Disease and T1 mapping [26] have shown promise in distinguishing exudative from transudative pleural effusions without contrast material.


Workup of Pleural Effusion or Pleural Disease. Radiography Chest Consensus recommendations endorse chest radiography as the initial imaging modality for patients with recent pneumonia and suspected pleural effusion [27,28]; however, there are limited empiric data to support these recommendations. Posteroanterior (PA) and lateral radiographs have a significantly greater sensitivity for the detection of parapneumonic effusions than single-view AP radiographs. In a retrospective analysis of patients from the Community-Acquired Pneumonia Organization international cohort study, PA and lateral radiographs had a sensitivity of 83.9% versus 67.3% for AP radiographs when using CT as the reference standard [29]. Single-view PA, single lateral view, or single-view AP radiographs have been shown to have statistically equivalent sensitivities for detection of parapneumonic effusions [30], with most missed parapneumonic effusions occurring in patients with coexistent lower lobe consolidation [30]. The specificity of chest radiography for the detection of complicated parapneumonic effusions, defined as those requiring thoracentesis, is modest. For example, in a retrospective study of 66 patients undergoing thoracentesis for parapneumonic effusions, chest radiography had a specificity of 60% for the detection of complicated parapneumonic effusions [31].


Workup of Pleural Effusion or Pleural Disease. US Chest Identification of a pleural effusion for possible US-guided thoracentesis is currently the primary reason for chest US [32]. Current American Association for Thoracic Surgery consensus guidelines recommend thoracic US for the diagnostic evaluation of pleural space infection (class I), typically occurring in patients with prior imaging documenting the presence of a pleural effusion [13]. US findings of septations [33,34], increased echogenicity of the pleural effusion [31,35], pleural thickening [36], and microbubbles [37] are associated with parapneumonic effusion/empyema. A retrospective study of 66 patients with suspected parapneumonic effusion found that US chest had a significantly higher specificity (90%, 95% CI, 76.3%-97.2%) and a nonsignificant difference in sensitivity (69.2%, 95% CI, 48.2%-87.7%) compared with CT chest for the diagnosis of complicated parapneumonic effusion [31]. A retrospective comparison of US chest and CT chest in pediatric patients found similar accuracy for the detection of parapneumonic effusion [38].


Workup of Pleural Effusion or Pleural Disease. CT Chest With IV Contrast CT chest with IV contrast or CTA chest with IV contrast is regarded as the reference standard for the noninvasive assessment of thoracic injury in patients with chest trauma, regardless of severity, and a clinical indication for imaging [42]. The goal of CT chest with IV contrast is to identify hemothorax and contrast extravasation. The incidence of pleural effusion on chest CT in minor blunt trauma is unknown; however, in a retrospective study of 2,440 multiple trauma patients undergoing whole body CT with IV contrast, 2.2% had an incidental pleural effusion [43]. In a secondary analysis of the prospective observational NEXUS Chest and NEXUS Chest CT studies of patients with major or minor blunt trauma, 1.8% of patients had a hemothorax on CTA chest with IV contrast [44].


Workup of Pleural Effusion or Pleural Disease. CT Chest Without and With IV Contrast There is no relevant literature to support the use of CT chest without and with IV contrast in the initial imaging of recent minor blunt trauma with suspected pleural effusion.


Workup of Pleural Effusion or Pleural Disease. CTA Chest With IV Contrast CTA chest with IV contrast or CT chest with IV contrast is regarded as the reference standard for the noninvasive assessment of thoracic injury in patients with chest trauma and a clinical indication for imaging [42]. The goal of


Workup of Pleural Effusion or Pleural Disease. Workup of Pleural Effusion or Pleural Disease CTA chest with IV contrast is to identify hemothorax and contrast extravasation. The incidence of pleural effusion on chest CT in minor blunt trauma is unknown; however, in a retrospective study of 2,440 multiple trauma patients undergoing whole body CT with IV contrast, 2.2% had an incidental pleural effusion [43]. In a secondary analysis of the prospective observational NEXUS Chest and NEXUS Chest CT studies of patients with major or minor blunt trauma, 1.8% of patients had a hemothorax on CTA chest with IV contrast [44].


Workup of Pleural Effusion or Pleural Disease. Image-Guided Aspiration Chest There is no relevant literature to support the use of image-guided aspiration chest in the initial imaging of recent minor blunt trauma with suspected pleural effusion.


Workup of Pleural Effusion or Pleural Disease. MRI Chest Without and With IV Contrast There is no relevant literature to support the use of MRI chest without and with IV contrast in the initial imaging of recent minor blunt trauma with suspected pleural effusion.


Workup of Pleural Effusion or Pleural Disease. MRI Chest Without IV Contrast There is no relevant literature to support the use of MRI chest without IV contrast in the initial imaging of recent minor blunt trauma with suspected pleural effusion.


Workup of Pleural Effusion or Pleural Disease. Radiography Chest Chest radiography is considered a first-line imaging test for patients with chest trauma and a clinical indication for imaging [46]. In the prospective NEXUS Chest CT trial, blunt trauma patients without an abnormal chest radiograph and 6 clinical criteria could avoid an unnecessary chest CT (sensitivity 99.2%; 95% CI, 95.4%-100%, specificity 20.8%; 95% CI, 19.2%-22.4%) [47]. A meta-analysis of the pooled sensitivity and specificity of chest radiographs for the detection of hemothorax in patients with chest trauma was 54% (95% CI, 33%-75%) and 99% (95% CI, 94%-100%), respectively, when using chest CT as the reference standard [48]. A study of 24 patients using only PA radiographs found a similar sensitivity of 62.5% and specificity of 100% for the detection of pleural effusions in patients with chest trauma [49]. In 2 prospective series of patients with minor blunt thoracic trauma and an initial normal chest radiograph, 7.4% to 11.8% had a pleural effusion on follow-up radiography within 2 weeks, clinically ascribed as a delayed hemothorax [39,40]. A delayed hemothorax on chest radiographs after minor blunt thoracic trauma was significantly more likely in patients with at least 1 fracture between the third and ninth ribs [50].


Workup of Pleural Effusion or Pleural Disease. US Chest The sensitivity and specificity of chest US for only minor blunt trauma has not been reported. Identification of a hemothorax for possible US-guided thoracentesis is the primary reason for chest US [32]. A recent meta-analysis reported chest US had a 60% sensitivity (95% CI, 31%-86%) and a 98% specificity (95% CI, 94%-99%) for traumatic hemothorax [51].


Workup of Pleural Effusion or Pleural Disease. Variant 3: Dyspnea, cough, or chest pain with suspected pleural effusion, noninfectious. Initial imaging. CT Chest With IV Contrast In patients with suspected malignant pleural effusion or suspected unilateral pleural effusion with an increased pretest probability of malignancy, CT chest with IV contrast is recommended [52,53], although this is not limited to patients with dyspnea, cough, or chest pain. Acquiring the CT scan 60 seconds after the contrast bolus improves visualization of pleural abnormalities associated with malignancy [19].


Workup of Pleural Effusion or Pleural Disease. CT Chest Without and With IV Contrast There is no relevant literature to support the use of CT chest without and with IV contrast in the initial imaging of dyspnea, cough, or chest pain with suspected noninfectious pleural effusion.


Workup of Pleural Effusion or Pleural Disease. CT Chest Without IV Contrast There is no relevant literature to support the use of CT chest without IV contrast in the initial imaging of dyspnea, cough, or chest pain with suspected noninfectious pleural effusion. Heart failure, liver failure, and renal failure are common noninfectious causes of pleural effusion, and these patients may present with dyspnea, cough, or chest pain and undergo CT chest without IV contrast as part of their diagnostic workup [54,55].


Workup of Pleural Effusion or Pleural Disease. CTA Chest With IV Contrast In patients with dyspnea, cough, or chest pain and suspected noninfectious pleural effusion, CTA chest with IV contrast is typically performed when there is clinical concern for pulmonary embolism [56] or aortopathy [57]. Pleural effusions in these patients are usually small and not associated with adverse clinical outcomes [57,58].


Workup of Pleural Effusion or Pleural Disease. Workup of Pleural Effusion or Pleural Disease MRI Chest Without and With IV Contrast There is no relevant literature to support the use of MRI chest without and with IV contrast in the initial imaging of dyspnea, cough, or chest pain with suspected noninfectious pleural effusion. Incidental pleural effusions have been reported in a minority of patients undergoing MRI with contrast for dyspnea, cough, or chest pain. For example, 6.6% (34/514) of patients had a moderate or large pleural effusion on contrast-enhanced MRA ordered for pulmonary embolism evaluation [59], and 4.3% (17/399) patients had a pleural effusion on stress cardiac MRI for possible acute coronary syndrome [60].


Workup of Pleural Effusion or Pleural Disease. MRI Chest Without IV Contrast There is no relevant literature to support the use of MRI chest without IV contrast in the initial imaging of dyspnea, cough, or chest pain with suspected noninfectious pleural effusion.


Workup of Pleural Effusion or Pleural Disease. Radiography Chest Consensus recommendations endorse chest radiography as the initial imaging modality for patients with suspected noninfectious pleural effusion [7,61]; however, there are limited empiric data to support these recommendations.


Workup of Pleural Effusion or Pleural Disease. US Chest Identification of a pleural effusion for possible US-guided thoracentesis is currently the primary reason for chest US [32]. Chest US is increasingly used as part of the diagnostic pathway for patients in the emergency department [62] and in the intensive care setting [63]. A recent meta-analysis found that chest US had a pooled sensitivity of 91% (95% CI, 83%-96%) and specificity of 92% (95% CI, 82%-97%) using CT as the reference standard for identification of pleural effusion in patients in the intensive care unit [63]. Adding chest US to the conventional diagnostic pathway has been shown to reduce the time to final diagnosis in the emergency department in patients with infectious and noninfectious causes of dyspnea [64].


Workup of Pleural Effusion or Pleural Disease. Variant 4: Pleural effusion incidentally detected on incomplete thoracic imaging study. Next imaging study. The frequency of an incidental pleural effusion detected on an incomplete thoracic imaging study including neck, spine, and abdomen varies based on the indication and type of imaging modality, in the range of 1% to 5% [65-71]. The clinical significance of these incidental pleural effusions is variable. In a retrospective study of patients undergoing run-off CTA, 4.2% (9/214) had an incidental pleural effusion, leading to the diagnosis of pneumonia in 22% (2/9) and optimization of heart failure therapy in 44% (4/9) [72]. However, in a study of 352 patients undergoing MRA of the abdomen, pelvis, and lower extremities, 2.9% had an incidental pleural effusion, and no patients required follow-up diagnostic testing or change in therapy.


Workup of Pleural Effusion or Pleural Disease. CT Chest With IV Contrast There is no relevant literature to support the use of CT chest with IV contrast as the next imaging study following a pleural effusion incidentally detected on prior abdominal imaging. The recommendation for a follow-up CT chest with IV contrast should be based on clinical assessment (eg, clinical suspicion of malignancy).


Workup of Pleural Effusion or Pleural Disease. CT Chest Without and With IV Contrast There is no relevant literature to support the use of CT chest without and with IV contrast as the next imaging study following a pleural effusion incidentally detected on prior abdominal imaging. The recommendation for a follow- up CT chest without and with IV contrast should be based on clinical assessment.


Workup of Pleural Effusion or Pleural Disease. CT Chest Without IV Contrast There is no relevant literature to support the use of CT chest without IV contrast as the next imaging study following a pleural effusion incidentally detected on prior abdominal imaging. The recommendation for a follow-up CT chest without IV contrast should be based on clinical assessment (eg, clinical suspicion of malignancy).


Workup of Pleural Effusion or Pleural Disease. CTA Chest With IV Contrast There is no relevant literature to support the use of CTA chest with IV contrast as the next imaging study following a pleural effusion incidentally detected on prior abdominal imaging. The recommendation for a follow-up CTA chest with IV contrast should be based on clinical assessment.


Workup of Pleural Effusion or Pleural Disease. MRI Chest Without and With IV Contrast There is no relevant literature to support the use of MRI chest without and with IV contrast as the next imaging study following a pleural effusion incidentally detected on prior abdominal imaging. The recommendation for a follow-up MRI chest without and with IV contrast should be based on clinical assessment.


Workup of Pleural Effusion or Pleural Disease. Workup of Pleural Effusion or Pleural Disease MRI Chest Without IV Contrast There is no relevant literature to support the use of MRI chest without IV contrast as the next imaging study following a pleural effusion incidentally detected on prior abdominal imaging. The recommendation for a follow- up MRI chest without IV contrast should be based on clinical assessment.


Workup of Pleural Effusion or Pleural Disease. Radiography Chest There is no relevant literature to support the use of chest radiography as the next imaging study following a pleural effusion incidentally detected on prior abdominal imaging. The recommendation for a follow-up chest radiograph should be based on clinical assessment (eg, clinical suspicion of malignancy).


Workup of Pleural Effusion or Pleural Disease. 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.


Workup of Pleural Effusion or Pleural Disease. For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. Introduction/Background Thoracic outlet syndrome (TOS) denotes the clinical entity that occurs with compression of the brachial plexus, subclavian artery, and/or subclavian vein at the superior thoracic outlet. There are three distinct spaces that can be implicated in TOS. Narrowing of each space results in slightly different presentations because of differing severity of impingement on the transiting neurovascular structures [1,2]. The costoclavicular triangle consists of the clavicle superiorly, the anterior scalene muscle posteriorly, and the first rib inferiorly. All three neurovascular structures pass through this space. Narrowing of this space tends to cause venous symptoms, frequently denoted venous TOS (vTOS), with varying degrees of additional symptoms due to arterial or brachial plexus compression. The interscalene triangle consists of the anterior scalene muscle, middle scalene muscle, and first rib. Trunks of the brachial plexus and the subclavian artery pass through this space; narrowing here causes neurological dominant TOS (nTOS), arterial dominant (aTOS), or combinations of both. The pectoralis minor space, defined by the pectoralis minor muscle anteriorly and chest wall posteriorly, is essentially an extension of the thoracic outlet and can result in varying degrees of compression similar to the costoclavicular space.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. During extreme shoulder abduction, the costoclavicular space is naturally narrowed. Anatomical variants such as a cervical rib can cause narrowing of the scalene triangle. Other possible sources of compression include anomalous first rib, C7 transverse process, or post-traumatic changes from prior clavicular or rib fractures. In patients who perform activities that require repetitive upper-extremity movement, such as swimming or throwing, or in patients who are not involved in excessive overhand motion but who have an anatomic predisposition to TOS, repetitive stress can lead to symptoms of TOS [3]. The subclavius muscle may hypertrophy, further narrowing the costoclavicular space, and the repetitive stress leads to thickening and fibrosis, notably in the subclavian vein wall, with restrictive fibrotic tissue surrounding the vein. Eventually, there is damage of the intima, resulting in luminal narrowing and a scarred, thrombogenic surface within the vein. Arterial changes in TOS similarly include intimal damage and thrombosis, with additional concerns of distal embolization and aneurysm formation. Neurological symptoms include chronic arm and hand paresthesia, numbness, or weakness.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. Although the exact prevalence of TOS is unknown, symptomatic TOS has been estimated to be 10 per 100,000 [4]. The current management of TOS is variable [5-11]. Understanding the various anatomic spaces, causes of narrowing, and resulting neurovascular changes are important in choosing and interpreting radiological imaging, which may be performed to help diagnose TOS and plan for intervention.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. This document has separated imaging appropriateness based on neurogenic, arterial, or venous symptoms, acknowledging that some patients may present with combined symptoms that may require more than one study to fully resolve. Additionally, in the postoperative setting, a new symptom may indicate a complication. Consultation


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. aResearch Author, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts. bMassachusetts General Hospital, Boston, Massachusetts. cPanel Chair, Massachusetts General Hospital, Boston, Massachusetts. dPanel Chair, University of Chicago, Chicago, Illinois. ePanel Chair, University of Utah, Salt Lake City, Utah. fPanel Vice-Chair, Emory Healthcare, Atlanta, Georgia. gUC San Diego Health, San Diego, California. hThe University of Texas MD Anderson Cancer Center, Houston, Texas. iScripps Green Hospital, La Jolla, California; Society for Vascular Surgery. jMayo Clinic, Rochester, Minnesota. kUniversity of Alabama at Birmingham, Birmingham, Alabama. lMayo Clinic, Rochester, Minnesota. mUniversity of Virginia, Charlottesville, Virginia. nUniversity of California Los Angeles, Los Angeles, California; American Academy of Neurology. oVanderbilt University Medical Center, Nashville, Tennessee; American College of Chest Physicians. pLoyola University Medical Center, Maywood, Illinois. qUT Southwestern Medical Center, Dallas, Texas. rDuke University School of Medicine, Durham, North Carolina; The Society of Thoracic Surgeons. sUT Southwestern Medical Center, Dallas, Texas. tSpecialty Chair, Atlanta VA Health Care System and Emory University, Atlanta, Georgia. uSpecialty Chair, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin. vSpecialty Chair, UMass Memorial Medical Center, Worcester, Massachusetts.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. 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.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. Reprint requests to: publications@acr.org


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. Thoracic Outlet Syndrome


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. with a radiologist may be useful at the time of examination ordering to optimize the study for the prevailing clinical symptom.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. When contrast is indicated, scan acquisition is typically performed with a contralateral antecubital intravenous (IV) injection, with either an empiric scan delay of 15 to 20 seconds or bolus tracking over the ascending aorta [12,13]. Some centers add the additional step of placing the contralateral arm in abduction (with the symptomatic ipsilateral arm in the neutral position) in order to minimize streak artifact [14].


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. All elements are essential: 1) timing, 2) reconstructions/reformats, and 3) 3-D renderings. Standard CTs with contrast also include timing issues and recons/reformats. Only in CTA, however, is 3-D rendering a required element. This corresponds to the definitions that the CMS has applied to the Current Procedural Terminology codes.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. CT venography (CTV) is obtained separately for each arm position 120 to 180 seconds after IV injection of iodinated contrast [6] in order to obtain venous opacification. The contrast injection should be performed in either the contralateral arm or other location. Multiplanar reformations are then produced to evaluate the thoracic space and true axial compression of the vessel. Center-line and volume-rendered images may also be produced to aid in visualization.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. CTA chest and CTV chest specifically denote studies tailored to evaluating the chest and thoracic outlet. These include evaluation of central vessels as well as subclavian and axillary arteries and veins, respectively. This is distinct from CTA upper extremity and CTV upper-extremity protocols, which are designed to evaluate the entire limb peripherally to the level of the wrist.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. Contrast-enhanced 3-D MR angiography (MRA) techniques have been described at both 1.5T and 3T to assess for TOS [19]. Breath-hold arterial phase contrast-enhanced 3-D MRA and equilibrium phase imaging is obtained using a 3-D gradient-echo pulse sequence with fat suppression. These can be obtained in both neutral and stressed positions with the exact protocol customized to institutional needs. A coronal oblique 3-D slab of the MRA is often obtained covering bilateral subclavian and axillary vessels. Unenhanced mask imaging is followed by multiphase contrast-enhanced dynamic acquisition in the same orientation. Noncontrast time-of-flight MRA may be considered, particularly in patients with contraindications to gadolinium-based contrast; however, these techniques suffer from flow artifacts, which could lead to false diagnosis of stenosis or thrombosis [19]. Noncontrast MRA


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. also requires long acquisition times when combined with postural maneuvers that may be difficult to achieve for patients with severe clinical symptoms.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. Contrast-enhanced 3-D MR venography (MRV) techniques have been described at both 1.5T and 3T to assess for vTOS [19]. Breath-hold venous phase contrast-enhanced 3-D MRV and equilibrium phase imaging is obtained using a 3-D gradient-echo pulse sequence with fat suppression. These can be obtained in both neutral and stressed positions with the exact protocol customized to institutional needs. A coronal oblique 3-D slab is often obtained covering bilateral subclavian and axillary vessels. Unenhanced mask imaging is followed by multiphase contrast- enhanced dynamic acquisition in the same orientation. Noncontrast time-of-flight MRV may be considered, particularly in patients with contraindications to gadolinium-based contrast; however, these techniques suffer from flow artifacts that could lead to false diagnosis of stenosis or thrombosis [19]. Noncontrast MRV also requires long acquisition times when combined with postural maneuvers that may be difficult to achieve for patients with severe clinical symptoms.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. CTA chest and CTV chest specifically denote studies tailored to evaluate the chest and thoracic outlet. These include evaluation of central vessels as well as subclavian and axillary arteries and veins, respectively. This is distinct from CTA upper extremity and CTV upper-extremity protocols, which are designed to evaluate the entire limb peripherally to the level of the wrist.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. Discussion of Procedures by Variant Variant 1: Neurogenic thoracic outlet syndrome. Initial imaging and follow-up imaging after surgery or intervention. Arteriography Upper Extremity Selective upper-extremity arteriography is unable to directly image neurologic structures. This procedure is therefore not considered a first-line test for nTOS pre- or postoperatively.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. Catheter Venography Upper Extremity Dedicated endovascular catheter venography is unable to directly image neurologic structures. This procedure is therefore not considered a first-line test for nTOS pre- or postoperatively.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. CT Chest CT for the evaluation of nTOS is limited by the lack of resolution of neural structures, although evaluation of the space sizes gives secondary indicators that may aid in diagnosis [13]. The goal is to demonstrate anatomical narrowing that could cause neurovascular compression. Findings include effacement of fat within the respective space and distortion or narrowing of the space with provocative or stress positioning.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. To also define adjacent vascular structures, a CT with IV contrast is sufficient for evaluation of nTOS [12,13].


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. CT allows quantification of the change in costoclavicular or interscalene spaces with provocative maneuvers [12,13], the presence of bony abnormalities [20,21], or superior sulcus pathology [22].


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. CT without IV contrast may be performed in the postintervention setting to evaluate interval changes in the thoracic outlet and assess adequate decompression. If there is a clinical concern for arterial or venous compromise, postintervention for patients with nTOS, imaging should be guided by those Variants.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. CTA Chest CTA does not provide further evaluation of the neurologic structures as compared with chest CT. If there are overlapping symptoms with aTOS or vTOS, review of the other Variants in this document may help with protocol optimization.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. CTV Chest CTV does not provide further evaluation of the neurologic structures as compared with chest CT. If there are overlapping symptoms, review of the other Variants in this document may help with protocol optimization.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. MRI Chest MRI has inherent advantages over ultrasound (US) in its ability to delineate extravascular anatomy, particularly in anatomic sites with poor sonographic windows, and MRI has advantages over CT in its characterization and differentiation of soft tissues.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. Thoracic Outlet Syndrome


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. For evaluation of patients with nTOS, definition of the brachial plexus and cervical spine and dynamic evaluation of neurovascular bundles in the costoclavicular, interscalene, and pectoralis minor spaces are required. Noncontrast MRI can be sufficient to diagnose nTOS.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. In one study, for patients with nTOS, the neurovascular bundle was most commonly compressed in the costoclavicular space, mostly secondary to position, and very rarely compressed in the pectoralis minor space [16]. The cause of TOS was congenital bone variations in 36%, congenital fibromuscular anomalies in 11%, and positional in 53%. In 5%, there was unilateral brachial plexitis in addition to compression of the neurovascular bundle. Severe cervical spondylosis was noted in 14%, contributing to TOS symptoms [16].


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. MRI without IV contrast may also be performed in the postintervention setting to evaluate interval changes in the thoracic outlet and assess adequate decompression. Postcontrast imaging may additionally be useful to assess the soft tissues for inflammatory or neoplastic conditions.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. MRA Chest Contrast-enhanced 3-D MRA techniques do not provide evaluation of the neurologic structures. If there are overlapping symptoms, review of the other Variants in this document may help with protocol optimization.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. MRV Chest Contrast-enhanced 3-D MRV techniques do not provide adequate evaluation of the neurologic structures. This procedure is therefore not considered a first-line test for nTOS pre- or postoperatively.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. Radiography Chest Chest radiography is frequently used as an initial imaging modality in suspected TOS. Osseous abnormalities associated with TOS are frequently easily diagnosed by chest radiographs. These include first rib anomalies [20], cervical ribs [23], congenital osseous malformations [24,25], and focal bone lesions [26]. Soft-tissue lesions, such as lung neoplasms [27], may also be evaluated, although the negative predictive value of chest radiographs is low, such that cross-sectional imaging is a necessary part of a complete TOS workup. In the postoperative setting, radiographs may be useful to confirm osseous changes and evaluate for postoperative complications, such as pneumothorax.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. US Duplex Doppler Subclavian Artery and Vein US is widely used as an imaging modality in the initial evaluation of patients with suspected arterial or venous pathology. Although many patients with nTOS have additional symptoms due to arterial or venous compression, US is not as valuable in assessing direct neurological involvement. Real-time duplex US can be used to evaluate the cross-sectional area of the costocervical space with and without provocative maneuvers [28]. Diagnosis of compressive effects upon the brachial plexus is a challenge [29], and symptoms of TOS may unmask a deeper regional pathology such as a Pancoast tumor or cervical spondylopathy, requiring further imaging. If there is reason to believe that symptoms could be related to hypertrophy of the anterior scalene muscles, US could be used for guidance to inject anesthetic in an attempt to confirm nTOS [30]. The procedure is considered diagnostic of nTOS if the patient experiences relief of symptoms after the injection. In the postoperative setting, US can be useful to evaluate vessel patency and complications such as postoperative hematoma or fluid collection.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. Variant 2: Venous thoracic outlet syndrome. Initial imaging and follow-up imaging after surgery or intervention. Arteriography Upper Extremity Selective upper-extremity arteriography may be used to evaluate extrinsic compression of the subclavian artery; however, it does not provide diagnostic assessment of the subclavian vein. This procedure is therefore not considered a first-line test for vTOS. In the postprocedure setting, catheter arteriography may be performed to evaluate and intervene on suspected or confirmed arterial complications.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. Catheter Venography Upper Extremity Diagnostic venography may be performed for suspected vTOS in which the veins of the affected extremity are catheterized, and contrast injection is performed via the catheter during digital subtraction acquisition in both neutral and stressed positions. Typical findings include narrowing of the subclavian vein with appearance of venous collateral vessels. These are generally seen projecting over the thorax or across the neck. Total occlusion of the subclavian vein may be present in chronic or acute TOS, and all findings may be present on only stressed position venography or at stress and neutral positions.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. As part of the evaluation for surgical decompression, patients may also undergo contralateral venography as well as catheter-directed thrombolysis. Angioplasty is not typically performed in the chronic setting, and at some centers, it is generally avoided prior to surgical decompression. In patients with total or near-total subclavian vein occlusion, endovascular recanalization of the subclavian vein may be attempted, and, if successful, a peripherally inserted central venous catheter is occasionally inserted and positioned so that it courses across the newly recanalized venous segment. It is then left indwelling until after surgical decompression is performed so as to preserve a route of intraluminal access across the diseased subclavian vein segment.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. One advantage of venography as a diagnostic tool is that other presurgery interventions may be performed, including intravascular thrombolysis, thrombectomy, and angioplasty. For postsurgical decompression, catheter venography is often indicated for evaluation of residual narrowing and possible US angioplasty of the diseased or stenosed segment with the external compression [31,32]. Intravascular US (IVUS) may be used as an adjunct in the postoperative setting to evaluate residual lumen size and presence of webs and has been shown to detect a higher degree of stenosis compared with venography alone [33].


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. CT Chest For noncontrast chest CT, the goal is to demonstrate anatomical narrowing that could cause vascular compression. Findings include effacement of fat within the respective space and distortion or narrowing of the space with provocative or stress positioning.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. Given the enhanced visualization of vascular structures with contrast, chest CT with IV contrast is preferred for evaluation of vTOS, and the acquisition is typically performed with a contralateral antecubital injection of contrast material.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. Chest CT without IV contrast may be performed in the postintervention setting to evaluate interval changes in the thoracic outlet and assess adequate decompression. However, chest CT with IV contrast has the advantage of providing assessment of vascular patency, which is a potential complication in the postintervention setting for patients with vTOS.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. CTA Chest CTA is performed to evaluate arterial compression and is therefore of limited use in the evaluation of vTOS. If there are overlapping symptoms, review of the other Variants in this document may help with protocol optimization.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. CTV Chest CTV is performed to evaluate venous compression in neutral and elevated arm positions. Venous compression is often present with abduction in asymptomatic patients, and therefore this finding alone may be insufficient to diagnose vTOS. Venous thrombosis and presence of collateral venous circulation essentially bypassing the thoracic outlet confirms the existence of hemodynamically significant vTOS [1].


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. Multiple studies have demonstrated the utility of CTV with IV contrast in evaluation of the upper-limb veins; however, reliance on axial slices alone can lead to misrepresentation of the degree of any stenosis, with one study showing underestimation of stenosis found in 43% of transverse CT scans but only in 10% of sagittal reformations. Overestimation of stenosis was also more frequent on surface displays with 3-D shading (16%) than on volume- rendered images (7%) [12], thus advancing the case for evaluation of these studies using these multiplanar tools in addition to standard reformations.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. CTV may be performed in the postintervention setting to evaluate interval changes in the thoracic outlet, assess adequate decompression, and follow-up on vessel patency or complications. Recurrent or persistent venous thrombosis may require reintervention.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. MRI Chest MRI for vTOS is performed to delineate anatomy and evaluate the pertinent anatomic spaces in both neutral and arms-abducted positions. Noncontrast MRI findings include effacement of fat adjacent to the subclavian vein. T1- weighted imaging performed in sagittal and axial planes can also demonstrate causative lesions, including cervical ribs, congenital fibromuscular anomalies, and muscular hypertrophy.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. Venous compression has been routinely demonstrated in all 3 compartments of the thoracic outlet in both asymptomatic and symptomatic populations when the arms were abducted [17]. Therefore, a finding of compression on abduction must be interpreted carefully. In symptomatic patients, venous thrombosis and collateral circulation


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. Thoracic Outlet Syndrome


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. are detected in both neutral and stressed arm positions, suggesting these findings are more reliably diagnostic of vTOS. They represent an objective, but likely chronic, finding of clinically significant venous compression.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. Given the need to assess the subclavian vein as well as venous collaterals in vTOS, noncontrast MRI is insufficient alone; the addition of IV contrast, particularly when an MRV protocol is performed, provides optimal assessment. The combination of soft-tissue and vascular assessment provided by MRI with IV contrast makes it an excellent modality when compared with US and CT; however, the longer acquisition times may prove difficult for highly symptomatic patients.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. MRI with IV contrast may also be performed in the postintervention setting to evaluate interval changes in the thoracic outlet and assess adequate decompression.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. MRA Chest MRA is not optimized for evaluation of the venous structures. If there are overlapping symptoms, review of the other variants in this document may help with protocol optimization. Interestingly, in one study [19], all patients with arterial compression were found to have venous compression during arm abduction. In patients with venous compression on one side, 71% had significant bilateral venous compression. Of these patients with bilateral imaging findings, only 21% had bilateral clinical symptoms or findings suggestive of TOS. Therefore, MRA has the potential to overdiagnose vTOS, and clinical symptoms must be taken into account.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. MRA may also be performed in the postintervention setting to evaluate interval changes in the thoracic outlet, assess adequate decompression, and confirm arterial patency.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. MRV Chest MRV is commonly performed in conjunction with MRI chest [34-36]. The primary MRV finding is narrowing of the subclavian vein; however, other findings, such as complete occlusion, collateral vessel formation, and visualization of thrombus, aid in the diagnosis of vTOS. Interestingly, in one study [19], all patients with arterial compression were found to have venous compression during arm abduction. In patients with venous compression on one side, 71% had significant bilateral venous compression. Of these patients with bilateral imaging findings, only 21% had bilateral clinical symptoms or findings suggestive of TOS. Therefore, MRV has the potential to overdiagnose vTOS, and clinical symptoms must be taken into account.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. MRV may also be performed in the postintervention setting to evaluate interval changes in the thoracic outlet, assess adequate decompression, and confirm arterial patency.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. Radiography Chest Because of the importance of identifying osseous structures that may impinge on the spaces of the thoracic outlet, chest radiography is useful in performing a robust evaluation for all types of TOS. As opposed to directly evaluating vascular structures, osseous abnormalities associated with TOS are frequently easily diagnosed by chest radiographs. These include first rib anomalies [20], cervical ribs [23], congenital osseous malformations [24,25], and focal bone lesions [26]. In the postoperative setting, radiographs may be useful to confirm osseous changes and evaluate for postoperative complications such as pneumothorax.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. US has a longstanding and well-documented role in the diagnosis of upper-extremity DVT [5,39], a common presentation of vTOS in the acute setting. Although the main advantage of US is the ability to directly compare between provocatively induced symptoms and concurrent direct vessel visualization, there is debate in the literature as to the significance of imaging findings, particularly with respect to maneuvers to minimize the thoracic outlet and associated spaces [28,37,40].


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. It is important to consider that certain etiologies of vTOS due to deeper pathology, such as Pancoast tumor or cervical spondylopathy, may require further investigation with cross-sectional imaging.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. Thoracic Outlet Syndrome In the postoperative setting, US can be useful to evaluate vessel patency and complications, such as postoperative hematoma or fluid collection.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. Variant 3: Arterial thoracic outlet syndrome. Initial imaging and follow-up imaging after surgery or intervention. Arteriography Upper Extremity Conventional catheter-based arteriography is effective at locating the exact point of vascular compression. In order to perform complete arteriography, catheter injection of contrast must be made from the aortic arch or the proximal subclavian artery. Injections and digital subtraction angiographic acquisitions are performed in both the neutral and abducted positions to assess dynamic changes. Vascular access is typically obtained from the femoral artery, although a radial artery approach can be considered. Even as a diagnostic tool alone, arteriography carries some risk. Because of its invasive nature and lack of information regarding surrounding structures, catheter-based angiography is largely only pursued if an endovascular intervention is envisioned.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. In the postintervention setting, catheter arteriography can provide definitive evaluation of arterial compression, occlusion, or other complication, such as dissection or aneurysm formation. This modality has the added advantage of possible immediate endovascular intervention.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. Catheter Venography Upper Extremity Diagnostic venography is not optimized for arterial evaluation. If there are overlapping symptoms, review of the other Variants in this document may help with protocol optimization.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. CT Chest For noncontrast CT, the goal is to demonstrate anatomical narrowing that could cause vascular compression. Findings include effacement of fat within the respective space and distortion or narrowing of the space with provocative or stress positioning.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. In a comprehensive study [13], a statistically significant difference was found between the distribution of the distances measured in the neutral and abducted positions in patients with arterial stenosis versus those without arterial stenosis.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. CT without IV contrast may be performed in the postintervention setting to evaluate interval changes in the thoracic outlet and assess adequate decompression. However, CT with IV contrast has the advantage of providing assessment of vascular patency, which is a potential complication in postintervention setting for patients with aTOS.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. CTA Chest CTA is performed to evaluate arterial compression in neutral and elevated arm positions. An indentation of the anterior wall of the subclavian artery as it passes around the anterior scalene muscle may be observed [13] as well as displacement of the subclavian vessels. Arterial compression is assessed by using arterial cross-sections produced by sagittal reformation of data. Sagittal reformation can show the location and severity of the arterial compression, and volume-rendered images allow simultaneous analysis of bones and subclavian artery. Arterial stenosis is expressed as the percentage of reduction of the cross-sectional area or the diameter of the artery [1].


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. Multiple studies have demonstrated the utility of CT in evaluation of the upper-limb arteries and veins; however, reliance on axial slices alone can lead to misrepresentation of the degree of any stenosis, with one study showing underestimation of stenosis found in 43% of transverse CT scans but only 10% of sagittal reformations. Overestimation of stenosis was also more frequent on surface displays with 3-D shading (16%) than on volume rendered images (7%) [12], advancing the case for evaluation of these studies on vascular workstations. For arterial compression, there is evidence of good correlation of CT findings with operative findings and results of decompression [41].


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. CTA may be performed in the postintervention setting to evaluate interval changes in the thoracic outlet, assess adequate decompression, and follow-up vessel patency or complications. Recurrent or persistent venous thrombosis may require reintervention.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. CTV Chest CTV is performed for evaluation of venous compression. This specific modality is therefore of limited use in aTOS. If there are overlapping symptoms, review of the other Variants in this document may help with protocol optimization.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. Thoracic Outlet Syndrome


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. MRI Chest MRI for aTOS is performed to delineate anatomy and evaluate the pertinent anatomic spaces in both neutral and arms-abducted positions. Noncontrast MRI findings include effacement of fat adjacent to the subclavian vein. T1- weighted imaging performed in sagittal and axial planes can also demonstrate causative lesions, including cervical ribs, congenital fibromuscular anomalies, and muscular hypertrophy.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. Given the need to assess the subclavian artery in aTOS, noncontrast MRI would be insufficient, with contrast- enhanced MR arteriography providing optimal assessment. The combination of soft-tissue and vascular assessment provided by MRI with contrast makes it an excellent modality when compared with US and CT; however, the longer acquisition times may prove difficult for highly symptomatic patients.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. MRI with IV contrast may also be performed in the postintervention setting to evaluate interval changes in the thoracic outlet and to assess adequate decompression.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. MRA Chest The primary MRA finding is narrowing of the subclavian artery; however, other findings, such as complete occlusion, collateral vessel formation, and visualization of thrombus, aid in the diagnosis of aTOS. MRA may help identify the severity of TOS and guide surgical or endovascular management [36]. If there is no evidence of compression on the abducted images, then imaging in the neutral position may be deferred. In the evaluation of TOS, if there is compression of the subclavian artery depicted on both sagittal T1-weighted and MRA, it may be denoted as aTOS. Further findings of aTOS that may be present include fixed or dynamic stenosis, aneurysm, mural thrombus, or distal emboli. Numerous MRA techniques have been described including noncontrast MRA, including inversion recovery methods for patients unable or unwilling to have contrast [42], simultaneous bilateral MRA [34], and dual-gadolinium injection protocols [35].


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. Ancillary findings include possible etiologies of aTOS, frequently cervical or anomalous first rib, scalene muscle, fibromuscular bands, or pectoralis minor tendon, and anomalous course of the subclavian artery within the scalene muscle.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. MRA may also be performed in the postintervention setting to evaluate interval changes in the thoracic outlet, assess adequate decompression, and confirm arterial patency.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. MRV Chest MRV is not needed in patients with aTOS. If there are overlapping symptoms, review of the other Variants in this document may help with protocol optimization.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. Radiography Chest Because of the importance of identifying osseous structures that may impinge on the spaces of the thoracic outlet, chest radiography is useful in performing a robust evaluation for all types of TOS. As opposed to directly evaluating vascular structures, osseous abnormalities associated with TOS are frequently easily diagnosed by chest radiographs. These include first rib anomalies [20], cervical ribs [23], congenital osseous malformations [24,25], and focal bone lesions [26]. In the postoperative setting, radiographs may be useful to confirm osseous changes and evaluate for postoperative complications such as pneumothorax.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. US Duplex Doppler Subclavian Artery and Vein As with vTOS, US is an excellent initial study in the evaluation of aTOS. The subclavian and axillary arteries can be directly visualized and assessed for aneurysmal change, arterial stenosis, and thrombosis. Dynamic arterial blood flow can be assessed during abduction. Findings include decrease in arterial diameter, changes in peak velocity, or reproducible symptoms considered to be diagnostic of aTOS. Evaluation of the cross-sectional area of the costocervical space may also be performed [28]. It is important to consider that although aTOS may be identified by US, certain etiologies due to deeper pathology, such as cervical spondylopathy, require further imaging.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. In the postoperative setting, US can be useful to evaluate vessel patency and complications, such as postoperative hematoma or fluid collection.


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. 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 rating round tabulations for each recommendation.


Thoracic Outlet Syndrome

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


Thoracic Outlet Syndrome

Thoracic Outlet Syndrome. Appropriateness Category Names and Definitions Relative Radiation Level Information Potential adverse health effects associated with radiation exposure are an important factor to consider when selecting the appropriate imaging procedure. Because there is a wide range of radiation exposures associated with different diagnostic procedures, a relative radiation level (RRL) indication has been included for each imaging examination. The RRLs are based on effective dose, which is a radiation dose quantity that is used to estimate population total radiation risk associated with an imaging procedure. Patients in the pediatric age group are at inherently higher risk from exposure, because of both organ sensitivity and longer life expectancy (relevant to the


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. 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.


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. Reprint requests to: publications@acr.org


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. Imaging of Invasive Breast Cancer


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. and later-stage breast cancer prior to treatment. Additionally, we investigate the use of surveillance imaging after completion of treatment, both in the asymptomatic and symptomatic settings. In the post-treatment setting, we differentiate recommended imaging algorithms by symptomatology, because routine screening of asymptomatic patients after treatment for metastatic disease does not provide survival benefit, but early detection of nonmetastatic recurrence does improve overall outcomes [10].


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. Special Imaging Considerations Although still investigational, whole body diffusion weighted imaging and whole body fluorine-18-2-fluoro-2- deoxy-D-glucose (FDG) PET/MRI may show improved staging compared with whole body FDG-PET/CT in patients with later-stage disease [11-15]. Further studies are warranted to support their use in routine practice.


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. Discussion of Procedures by Variant Variant 1: Newly diagnosed. Clinical stage I-IIA (early stage) breast cancer at presentation. Evaluation for locoregional disease (includes invasive ductal carcinoma [IDC], or invasive lobular carcinoma [ILC], or not otherwise specified [NOS]). Bone Scan Whole Body There is no evidence to support the use of Tc-99m bone scan whole body to evaluate for locoregional disease.


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. CT Chest, Abdomen, and Pelvis With IV Contrast Few studies have evaluated the use of CT chest, abdomen, and pelvis with intravenous (IV) contrast to determine locoregional disease. A study investigating the use of CT at evaluating locoregional disease, stages I to III, adding CT to mammogram, ultrasound (US) and physical examination correctly changed the surgical approach in 13.1% of patients, based on final pathology. However, CT failed to show any disease (false-negative) in 10.8% and had a low sensitivity for detecting multicentric and multifocal tumors [20].


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. CT Chest, Abdomen, and Pelvis Without IV Contrast There is no evidence to support the use of CT chest, abdomen, and pelvis without IV contrast to evaluate for locoregional disease.


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. Digital Breast Tomosynthesis Diagnostic Diagnostic mammography and US together can assess for extent of disease and tumor size. These imaging tests are usually already completed as part of the diagnostic workup (prior to pathological diagnosis). However, mammography is limited by breast density. In a prospective study of 111 consecutive women with newly diagnosed breast cancer, sensitivity of 2-D mammography for malignancy decreased from 100% in breasts that are almost entirely fatty to 45% in extremely dense breasts [22]. In addition, 2-D mammography was more sensitive than US in detecting ductal carcinoma in situ (DCIS) and less sensitive in detecting ILC.


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. Digital breast tomosynthesis (DBT) shows a higher overall sensitivity, compared with 2-D mammography, with a similar specificity. Overall sensitivity for DBT was 88.2% compared with 78.3% for 2-D mammography [23]. DBT also has a higher sensitivity for detecting multifocal, multicentric, and contralateral breast cancer [24,25]. The improved diagnostic performance of DBT over 2-D mammography in breast cancer staging was limited to women with nondense breasts in 1 study [24], but not others [25].


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. Due to patient positioning constraints, 2-D mammography and DBT have limited value for evaluating the axilla. In a single-institution retrospective study of 3,944 patients with breast cancer, mammography improved the sensitivity over US alone for distinguishing N0 to N1 from N2 and N3, but at a lower specificity [35]. After the American College of Surgeons Oncology Group (ACOSOG) Z0011 trial supported the omission of axillary lymph node dissection in women with <3 positive sentinel lymph nodes undergoing breast-conserving surgery and radiation therapy, some providers now request that radiologists not image the axilla in the setting of clinically node-negative disease [36]. Even when neoadjuvant chemotherapy is planned, radiologists should be thoughtful about whether to image the axilla, discussing risks and benefits with surgical colleagues, because it is not universally recommended [37].


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. PET/CT has the potential to have greater sensitivity than US for axillary staging because it uses a functional measurement instead of an anatomic determination (eg, cortical thickness, loss of fatty hilum) as criteria for determining suspicion for metastatic disease [42]. Surgical studies show that 21% to 33% of T1 and 45% to 60% T2 tumors with normal appearing lymph nodes have metastatic disease on pathological examination [43]. Thus, studies have queried whether a functional measurement might be better. One study retrospectively evaluated PET/CT in 826 consecutive patients with breast cancer and showed a sensitivity and specificity of 74.7% and 83,4%, respectively, for identifying metastatic disease. Studies show a negative predictive value (NPV) from 87% to 88% [39,44]. Other studies show the sensitivity and specificity for detecting lymph node metastasis as 79% and 100%, respectively [38]. However, Sohn et al [45] showed a higher sensitivity for US plus fine-needle aspiration (FNA) at determining lymph node status than PET/CT (83% versus 80%, respectively). Despite extensive scientific investigation, given the results above and the Z0011 trial, the role of PET/CT in determining locoregional extent is likely nominal.


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. Mammography Diagnostic Diagnostic mammography and US together can assess for extent of disease and tumor size. These imaging tests are usually already completed as part of the diagnostic workup (prior to pathological diagnosis). However, mammography is limited by breast density. In a prospective study of 111 consecutive women with newly diagnosed breast cancer, the sensitivity of 2-D mammography for malignancy decreased from 100% in breasts that are almost


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. Imaging of Invasive Breast Cancer entirely fatty to 45% in extremely dense breasts [22]. In addition, 2-D mammography was more sensitive than US in detecting DCIS and less sensitive in detecting ILC.


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. DBT shows a higher overall sensitivity, compared with 2-D mammography, with similar specificity. Overall sensitivity for DBT was 88.2% compared with 78.3% [23]. DBT has a higher sensitivity for detecting multifocal, multicentric, and contralateral breast cancer [24,25]. The improved diagnostic performance of DBT over 2-D mammography in breast cancer staging was limited to women with nondense breasts in 1 study [24], but not others [25].


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. Due to patient positioning constraints, 2-D mammography and DBT have limited value for evaluating the axilla. In a single-institution retrospective study of 3,944 patients with breast cancer, mammography improved the sensitivity over US alone for distinguishing N0 to N1 from N2 and N3, but at a lower specificity [35]. After the ACOSOG Z0011 trial supported the omission of axillary lymph node dissection in women with <3 positive sentinel lymph nodes undergoing breast-conserving surgery and radiation therapy, some providers may request that radiologists not image the axilla in the setting of clinically node-negative disease [36]. Radiologists can be thoughtful about whether to image the axilla, discussing risks and benefits with surgical colleagues, because it is not universally recommended [37].


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. Mammography With IV Contrast Several retrospective studies have compared the sensitivity and specificity of CEM with conventional 2-D and 3-D mammography, US, and MRI. Overall, CEM and MRI are superior to DM and DM/DBT imaging [47]. The sensitivities between CEM and MRI are comparable, with some studies showing improved sensitivities with CEM [48] and some showing MRI to be superior [49,50]. Overall sensitivities ranged from 92% to 100% [16,49,51-53], including CEM detecting 92.3% of satellite masses and up to 100% of contralateral cancers [28]. CEM and MRI show similar abilities to estimate tumor size (r = 0.72-0.89 versus 0.65-0.84), but studies have shown an improved positive predictive value (PPV) of CEM (52%-93%) compared with MRI (28-60%) [16,49,53]. Despite increased specificity over MR, limitations of contrast mammography in determining disease extent include evaluation of the axilla and other nodal groups as well as chest wall involvement [47], and there is evidence against using CEM to determine disease extent in lobular cancer, due to lower conspicuity [54].


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. MRI Breast Without and With IV Contrast MRI breast is useful for detecting additional cancers in the ipsilateral or contralateral breast [16,55], particularly in women with dense breasts [23,56,57]. A meta-analysis of 22 studies investigated MRI screening of the contralateral breast in women with newly diagnosed breast cancer. This meta-analysis reported contralateral malignancies that were detected by MRI in 131 of 3,253 women. Thus, the summary estimate for incremental cancer detection rate was 4.1%. In studies in which pathologic tumor stage was reported, all but 2 tumors were in situ or stage I, and of those 2 tumors, 1 was node-negative ILC (42 mm). Summary estimates were as follows: MRI-directed additional


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. Imaging of Invasive Breast Cancer biopsy in 9.3% of women (95% confidence interval [CI], 5.8%-14.7%) with PPV for malignancy of 47.9% (95% CI, 31.8%-64.6%). Where reported, 35.1% of MRI-detected cancers were DCIS (mean size = 6.9 mm) and 64.9% were invasive cancers (mean size = 9.3 mm) [58].


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. MRI can accurately assess tumor size for preoperative planning [50,59-61]. In a study involving 343 tumors, size measurements of cancers on breast MRI were within 5 mm of pathological size in 88% of patients [60]. Still, other studies using mastectomy specimens have shown that MRI underestimates primary tumor size in 21% and overestimates primary tumor size in 24% of cases [62]. MRI also overestimated the number of invasive lesions by 19% and underestimated the number of invasive lesions in 28% in the same study [62]. These data underscore the importance of using biopsy to pathologically confirm MRI findings instead of relying on them to alter surgical planning, especially when the MRI finding is nonmass enhancement [63].


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. In addition to tumor size assessment, some studies show a reduction in re-excision after preoperative MRI [64-68]. For example, in a study of 991 women, preoperative MRI changed the surgical procedure in 25% (157/626) of cases. In 81% (127/157), MRI benefited some patients, as otherwise occult carcinomas were removed (n = 122) and further biopsy prevented (n = 5) [67]. In this trial, the rate of mastectomy did not differ between patients undergoing preoperative MRI and those who did not. A recent multinational observational study at 27 centers also found that subjects receiving MR as part of routine clinical care had a significantly lower reoperation rate after breast conservation (8.5% versus 11.7%, P < .001) [69]. However, other large multicenter studies, such as the comparative effectiveness of MRI in breast cancer (COMICE) trial, showed the addition of MRI to conventional imaging was not significantly associated with a reduced reoperation rate, with 153 (19%) needing reoperation in the MRI group versus 156 (19%) in the non-MRI group (odds ratio [OR], 0.96; 95% CI, 0.75-1.24; P = .77) [70]. Although the findings are important, limitations from the COMICE trial are also noted, such as its inclusion of patients from several small centers where technical factors and varying degree of experience among interpreting radiologists could have influenced the MRI results. It is also not clear that the data from the MRI was incorporated into surgical planning, and nearly 7% of the group assigned to MRI did not actually have an MR interpreted (analyzed by intention to treat). When all breast cancer subtypes were included, a meta-analysis of 19 studies did not find evidence that MRI impacted the rates of re-excision, reoperation, or positive margins, but MRI was significantly associated with increased odds of receiving contralateral prophylactic mastectomy (OR, 1.91; 95% CI, 1.25-2.91; P = .003) [71]. This analysis of 85,975 women also showed that preoperative MRI was associated with increased odds of receiving mastectomy (OR, 1.39; 95% CI, 1.23-1.57; P < .001) [71]. Still, it is unknown whether some of the studies included in that meta-analysis had a bias in randomization (ie, women who were preplanned for mastectomies were more likely to have been referred rather than randomized to the preoperative MRI arm). As an example of this, in the multicenter international prospective analysis cited above [69], mastectomy was already planned based on conventional imaging in 22.4% (MRI group) versus 14.4% (no MRI group) (P < .001).


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. The data are different for ILC histological subtypes. For ILC, there is strong evidence that MRI improves surgical outcomes [72-81]. In a study with 70 cases of ILC, preoperative MRI reduced re-excision rates, particularly in young women with dense breasts [82]. In another study with 369 women, preoperative breast MRI was also associated with a reduction in repeat surgery (OR, 0.140; P < .001), without increasing mastectomy rates [76].


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. Although MR does lead to increased cancer detection, there is limited evidence that preoperative MRI improves survival or decreases recurrence, including data from multicenter analyses [61,68,83-85]. In 3,180 affected breasts in 3,169 women (median age, 56.2 years), 8-year disease-free survival did not differ between the MRI (97%) and the non-MRI (95%) groups (P = .87), and the multivariable model showed no significant effect of MRI on disease- free survival: hazard ratio (HR) for MRI (versus non-MRI) was 0.88 (95% CI, 0.52-1.51; P = .65); age, margin status, and tumor grade were associated with disease-free survival (all P < .05) [85]. Of the 31,756 patients included in a survival cohort (70% non-MRI and 30% MRI), breast MRI was not significantly associated with overall survival (HR, 0.91; 95% CI, 0.74-1.11, P = .35) or with disease-free survival (HR, 1.16; 95% CI, 0.81-1.67), even among the different histological subtypes. The lack of survival benefit extends also to patients with ILC, despite improved surgical outcomes in this population as described above [83]. One recent study did show lower recurrences (locoregional, distant and contralateral) in women who received a preoperative MRI, with a nonsignificant trend toward MR improving disease-free survival (P = .057) [86], and another study of 1,199 subjects did show improved overall survival in the group who received MRI [87].


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. Given these data, benefits of preoperative MRI for additional cancer detection or delineating extent of disease should be balanced with the possibility of a false-positive diagnosis leading to additional biopsy, unnecessary additional imaging, and potential delays in definitive treatment. Due to additional cancer detection on a per-patient


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. Imaging of Invasive Breast Cancer level, MRI is considered optional, despite a lack of definitive data supporting classical improved outcomes and continued controversy regarding potential harms. Considering the evidence above, MRI-detected suspicious masses >2 cm from the index malignancy or nonmass enhancement significantly larger than expected from mammographic/sonographic findings should be sampled before using MRI findings to alter surgical planning or change treatment recommendations.


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. MRI Breast Without IV Contrast There is no evidence to support the use of noncontrast breast MRI in evaluating extent of disease.


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. US is the most established noninvasive imaging test for assessing the axilla following a clinically or imaging detected suspicious lymph node. US features associated with a higher likelihood of malignancy include short-axis lymph node size >1 cm, cortical thickness of >0.3 cm, and an absence of a fatty hilum [90-93]. There is a wide range of reported sensitivity and specificity for axillary US, and none of these imaging features are specific enough to avoid the need for histologic sampling. The sensitivity ranges from 26.4% to 94%, and the specificity ranges from 53% to 98% [94-97]. Axillary US alone has a relatively low NPV to rule out metastatic disease [36,98]. A meta-analysis of 21 studies showed that US combined with needle biopsy improved the sensitivity from 61% to 79% [99-101]. US-guided core needle biopsy was superior to US-guided FNA in a meta-analysis of 1,353 patients with newly diagnosed invasive breast carcinoma, with a reported sensitivity of 88% for core biopsy and 74% for FNA [102]. Axillary US and an MRI performed similarly (sensitivity of 99.1% versus 97.4% and specificity 15.4% versus 15.4%, respectively) in evaluating axillary lymph nodes. Despite this performance, approximately 14% of women with breast cancer and negative imaging for axillary metastasis ultimately have metastatic disease on sentinel lymph node biopsy [103].


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. US Breast Diagnostic mammography and US together can assess for extent of disease and tumor size. These imaging tests are usually already completed as part of the diagnostic workup (prior to pathological diagnosis). The sensitivity of US for detecting cancer ranges from 79% to 94% [22,25,104,105]. The addition of DBT to US improved sensitivity for detecting both primary breast cancer and multicentric and multifocal disease, from 82.6% (nondense) and 91.6% (dense) with US alone to 97.7% with combined DBT and US [106]. However, DBT and mammography have limited added value over US alone for initial evaluation in women <40 years of age [105]. Although bilateral US use in women with primary breast cancer to evaluate for multicentric and multifocal disease shows a lower sensitivity than MRI (85.1% versus 71.1%), US showed higher accuracy and specificity than MRI (67.6% versus 39.3% and 69.2% versus 60.2%, respectively), suggesting that bilateral US may be an acceptable alternative to MRI for locoregional staging [57]. When compared with DM alone, supplemental US more accurately depicted the extent of disease needing wider excision in 17 of 96 (18%) breasts for which conservation was anticipated, corresponding to 17 of 30 (57%) breasts with mammographically occult disease [22]. Based on mammography/clinical examination, 2% to 3% of patients have synchronous bilateral cancer [107]. This risk for bilateral synchronous cancer is increased in patients less than 55 years of age or in those diagnosed with invasive lobular subtypes [108]. In 1 series with 9% contralateral synchronous malignancy, mammography detected 60%, US detected 80%, and MRI detected 90% (with the remainder detected on follow-up imaging) [22].


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. In addition to its role in the initial diagnostic workup, US is important in the secondary evaluation of a suspicious finding on MRI in the setting of evaluation of disease extent. US sensitivity and NPV are higher than those of DBT [109]. Compared with DBT, US showed a lower specificity (98.1% versus 78.9%) and similar PPV (66.7% versus 52.2%). However, a meta-analysis of second-look US following a suspicious finding on MRI showed heterogeneity in US performance, with the detection rate ranging from 22.6% to 82.1% (pooled detection rate 57.5%) and an 87.8% pooled NPV [110]. Therefore, a negative US is insufficient to obviate the need for an MRI biopsy in this setting.


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. There is no evidence supporting US as an accurate method for determining disease extent of those diagnosed with ILC subtype. Conventional imaging with mammography and/or US can significantly underestimate the extent of ILC [26,111-114]. For example, US specifically underestimated ILC tumor size by 27% (95% CI, 17%-37%) in a


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. Imaging of Invasive Breast Cancer study [113], and a different study showed that the greatest discrepancy between tumor size and pathologic size using US measurements was for the ILC subtype [26].


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. Variant 2: Newly diagnosed. Clinical stage I-IIA (early stage) breast cancer at presentation. Evaluation for distant disease (includes IDC, or ILC, or NOS). It has long been recognized that steroid receptor expression reflects intrinsic biologic diversity in breast cancer with treatment and survival implications, also determining patterns of metastatic spread. Historically, bone is the most likely site of breast cancer metastases (51%), followed by liver/soft tissue (19%), pleura (16%), lung (14%), and brain (4%) [115]. The higher percentage of bone metastases from breast cancer appears to be driven primarily by the majority of primary tumors expressing ER and/or PR. In 1 large multidecade study, 82% of patients with breast cancer who developed bone metastases had either ER and PR or ER positivity in the primary tumor [115].


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. A landmark study 2 decades ago transformed our field by discovering 5 distinct composite molecular portraits using quantitative analysis of breast cancer gene expression patterns; luminal A, luminal B, HER2-enriched, basal-like, and normal-like, providing a new type of disease characterization [116]. The molecular subtypes were linked to pattern and type of metastatic spread, as well as disease-specific survival [117,118]. For example, luminal cancers have a propensity to give rise first to bone metastases, HER2-enriched cancers to liver and lung metastases, and basal type cancers to liver and brain metastases [119,120]. These molecular subtypes share similarities with ER/PR expression and HER2 gene amplification but are not synonymous. Luminal subtypes more commonly have ER expression, HER2-enriched cancers more commonly exhibit HER2 expression, and triple-negative breast cancers are most often the basal breast cancer subtype. Although luminal subtypes have significantly better overall and relapse-free survival [118], they carry a long-term risk of recurrence, especially to bone, whereas basal and HER2 subtypes have a higher rate of recurrence in the first 4 years [121], which can be considered when planning frequency and type of surveillance imaging.


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. Bone Scan Whole Body Bone is the most common site for breast cancer metastasis; up to 70% of women with stage IV disease have bone metastasis, with the predilection for bone metastases not applying to basal-like tumors [117]. Up to 13.6% of women diagnosed with early stage breast cancer will develop bone metastasis within 15 years of diagnosis [122], even if the parent tumor is low grade [123]. Tc-99m bone scans detect early bone metastasis because of the new bone formation occurring at these sites [124] and have a 98% sensitivity for detecting early bone metastasis in symptomatic patients. However, bone scan is not helpful for asymptomatic women with newly diagnosed early stage breast cancer due to the low prevalence of metastasis (<1%) at initial diagnosis [125]. Whole body bone scans are performed in up to 35% of women with newly diagnosed breast cancer despite National Comprehensive Cancer Network (NCCN) guidelines recommending against routine staging in asymptomatic women with early stage breast cancer [125,126]. The unnecessary use of this imaging test and the further evaluation of false-positive findings can result in treatment delay [127]. There is no evidence to use whole body bone scan in the evaluation of distant disease in stage I to IIA breast cancer.


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. CT Chest, Abdomen, and Pelvis With IV Contrast National and international guidelines (American Board of Internal Medicine [ABIM]/ASCO, European Society for Medical Oncology [ESMO], and Spanish Society of Medical Oncology [SEOM]) discourage the use of imaging for staging in asymptomatic patients with newly diagnosed early stage breast cancer [128-130].


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. NCCN guidelines recommend chest, abdomen, and pelvic CT as an additional test prior to preoperative systemic therapy in clinical stage I to IIA if the tumor is >2 cm, >1 cm and immunohistochemical subtype is triple negative, or HER2+ or any size/subtype with known axillary nodal spread [126]. However, this test is often used in the staging evaluation of low-risk cancers, outside these guidelines, despite a lack of evidence suggesting that it improves detection of metastatic disease or increases survival. There is a lack of evidence demonstrating a benefit for the use of CT in asymptomatic individuals with clinical stage I or II disease outside the guidelines above. A survey of NCCN member institutions found that 11% of patients with stage I and 36.2% of patients with stage II received a staging CT of the chest. This resulted in 27% of patients diagnosed with pulmonary nodules requiring a mean 2.34 additional CTs (range 0-16) for follow-up. Of pulmonary nodules detected in asymptomatic women with early stage breast cancer, only 2% of these patients were ultimately diagnosed with pulmonary metastasis [131,132].


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. Imaging of Invasive Breast Cancer


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. CT Chest, Abdomen, and Pelvis Without and With IV Contrast The majority of clinical questions for abdominal and/or pelvic CT can be appropriately answered with a single- phase study as detailed in the ACR-SABI-SPR practice parameter for the performance of CT of the abdomen and CT of the pelvis [21].


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. CT Chest, Abdomen, and Pelvis Without IV Contrast There is no evidence to support the use of CT chest, abdomen, and pelvis without IV contrast in identifying distant disease.


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. Digital Breast Tomosynthesis Diagnostic There is no evidence to support the use of DBT to evaluate distant disease.


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. FDG-PET/CT Skull Base to Mid-Thigh According to the ABIM/ASCO, ESMO, and SEOM guidelines, there is insufficient evidence to routinely use FDG- PET/CT to evaluate for distant disease in asymptomatic women with early stage breast cancer [128-130].


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. NCCN guidelines recommend chest, abdomen, and pelvic CT as an additional test prior to preoperative systemic therapy to evaluate for distant disease if the tumor size is >2 cm (T2) or there are positive lymph nodes, or the tumor size is >1 cm (T1c) and HER2+, or there is triple-negative disease [126]. Although not definitive, and not currently recommended in the guidelines above, there is evidence that PET/CT may be useful in early stage breast cancer [133]. A recent study of 196 subjects [134] tested the utility of PET/CT in breast cancer and found the overall yield of unsuspected distant metastases was 14% (n = 27), including 0% for stage IIA, 13% for stage IIB (10/79), 22% for stage IIIA (9/41), 17% for stage IIIB (5/30), and 37% for stage IIIC (3/8). In another study of 303 patients, PET/CT demonstrated unknown metastatic disease in 4.9% (15/303), 0.8% in stage IIA, and 9.8% in stage IIB [135]. Finally, Groheux et al [136] performed a prospective study of 254 women with breast cancer, and PET/CT found unsuspected metastatic disease in 2.3% of stage IIA and 10.7% in stage IIB [128]. The performance of PET/CT was independent of cancer subtype, as shown in other studies on stage IIB disease [137]. Finally, a recent meta-analysis of 4,276 patients (29 studies) also found 11% (95% CI, 3%-22%) of patients with stage I and 20% (95% CI, 16%-24%) of patients with stage II breast cancer changed disease stage or management plan (including up or downstaging) with PET/CT [13]. Thus, there is some evidence to consider this test, even in early breast cancer, if the immunohistochemical subtype is HER2+/TN or the disease is locally advanced as described above.


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. Mammography Diagnostic There is no evidence to support the use of diagnostic mammography to evaluate distant disease.


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. Mammography With IV Contrast There is no evidence to support the use of diagnostic mammography with IV contrast to evaluate distant disease.


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. MRI Breast Without and With IV Contrast There is no evidence to support the use of MRI breast to evaluate distant disease.


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. MRI Breast Without IV Contrast There is no evidence to support the use of noncontrast breast MRI in evaluating extent of disease.


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. US Axilla There is no evidence to support the use of US axilla to evaluate distant disease.


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. US Breast There is no evidence to support the use of US breast to evaluate distant disease.


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. Variant 3: Newly diagnosed. Clinical stage IIB-III (late stage) breast cancer at presentation. Evaluation for locoregional disease (includes IDC, or ILC, or NOS). Bone Scan Whole Body There is no evidence to support the use of bone scan whole body for determining locoregional disease.


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. CT Chest, Abdomen, and Pelvis With IV Contrast Few studies have evaluated the use of CT to determine locoregional disease in breast cancer and so there is limited supporting evidence for this indication. In a study using CT to determine the size of the in-breast malignancy, surgical treatment was changed in 42 of 297 (14.1%) patients. The same study showed that CT failed to show the extent of disease in 10.8% of patients and overestimated the extent of disease in 1% of tumors. Notably, MRI was not included as a comparator [20]. An additional study looking at later stage (at least 2 cm) or higher risk (triple


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. negative or other biomarkers of risk such as high Ki67 or HER2+) found that CT predicted the N stage correctly in 64 of 80 patients (80%, 95% CI,70.0%-87.3%), with a sensitivity of 61.5% (CI,45.9%-75.1%) and a specificity of 97.6% (CI, 87.4%-99.6%). Despite the higher specificity of CT, MRI has better performance to detect multicentric/multifocal disease and estimate final pathologic size.


Imaging of Invasive Breast Cancer


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. CT Chest, Abdomen, and Pelvis Without IV Contrast There is no evidence to support the use of CT chest, abdomen, and pelvis without IV contrast for determining locoregional disease and guiding surgical management in late-stage disease.


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. Digital Breast Tomosynthesis Diagnostic Diagnostic mammography and US together can assess for extent of disease and tumor size. These imaging tests are usually already completed as part of the diagnostic workup (prior to pathological diagnosis). However, mammography is limited by breast density. In a prospective study of 111 consecutive women with newly diagnosed breast cancer, sensitivity of 2-D mammography for malignancy decreased from 100% in breasts that are almost entirely fatty to 45% in extremely dense breasts [22]. In addition, 2-D mammography was more sensitive than US in detecting DCIS and less sensitive at detecting ILC.


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. DBT shows higher overall sensitivity, compared with 2-D mammography, with similar specificity. Overall sensitivity for DBT was 88.2% compared with 78.3% for 2-D mammography [23]. DBT also has a higher sensitivity for detecting multifocal, multicentric, and contralateral breast cancer [24,25]. The improved diagnostic performance of DBT over 2-D mammography was limited to women with nondense breasts in 1 study [24], but not others [25].


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. Due to patient positioning constraints, 2-D mammography and DBT have limited value for evaluating the axilla. In a single-institution retrospective study of 3,944 patients with breast cancer, mammography improved the sensitivity over US alone for distinguishing N0 to N1 from N2 and N3, but at a lower specificity [35]. After the ACOSOG Z0011 trial supported the omission of axillary lymph node dissection in women with <3 positive sentinel lymph nodes undergoing breast-conserving surgery and radiation therapy, some providers may request that radiologists not image the axilla in the setting of clinically node-negative disease [36]. Although axillary US is not recommended for every patient [37], axillary abnormality visible on mammography is still considered an appropriate indication for sonographic axillary evaluation. Also, when neoadjuvant chemotherapy is planned, the NCCN recommends consideration of axillary US, with marker placement if a biopsy is performed, in addition to mammography [126].


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. Mammography Diagnostic Diagnostic mammography and US together can assess for extent of disease and tumor size. These imaging tests are usually already completed as part of the diagnostic workup (prior to pathological diagnosis). However, mammography is limited by breast density. In a prospective study of 111 consecutive women with newly diagnosed breast cancer, the sensitivity of 2-D mammography for malignancy decreased from 100% in breasts that are almost entirely fatty to 45% in extremely dense breasts [22]. In addition, 2-D mammography was more sensitive in detecting DCIS and less sensitive, compared with US, in detecting ILC.


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. DBT shows higher overall sensitivity, compared with 2-D mammography, with similar specificity. Overall sensitivity for DBT was 88.2% compared with 78.3% [23]. DBT has higher sensitivity for detecting multifocal, multicentric, and contralateral breast cancer than 2-D mammography alone [24,25]. The improved diagnostic performance of DBT over 2-D mammography in breast cancer staging was limited to women with nondense breasts in 1 study [24], but not others [25].


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. Due to patient positioning constraints, 2-D mammography and DBT have limited value for evaluating the axilla. In a single-institution retrospective study of 3,944 patients with breast cancer, mammography improved the sensitivity over US alone for distinguishing N0 to N1 from N2 and N3, but at a lower specificity [35]. After the ACOSOG Z0011 trial supported the omission of axillary lymph node dissection in women with <3 positive sentinel lymph nodes undergoing breast-conserving surgery and radiation therapy, some providers may request that radiologists not image the axilla in the setting of clinically node-negative disease [36]. When neoadjuvant chemotherapy is planned, the NCCN does recommend consideration of axillary US, with marker placement if a biopsy is performed, in addition to mammography [126].


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. Mammography With IV Contrast Several retrospective studies have compared the sensitivity and specificity of CEM with conventional 2-D and 3-D mammography, US, and MRI. Overall, CEM and MRI are superior to DM and DM/DBT imaging [47]. The sensitivities between CEM and MRI are comparable, with some studies showing improved sensitivities with CEM


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. Imaging of Invasive Breast Cancer [48], and some showing MRI to be superior [49,50]. Overall sensitivities ranged from 92% to 100% [16,49,51-53], including CEM detecting 92.3% of satellite masses and up to 100% of contralateral cancers [28]. CEM and MRI show similar abilities to estimate tumor size (r, 0.72-0.89 versus 0.65-0.84), but studies have shown improved PPV of CEM (52%-93%) compared with MRI (28-60%) [16,49,53]. Despite increased specificity over MR, limitations of contrast mammography in determining disease extent include evaluation of the axilla and other nodal groups as well as chest wall involvement [47], and there is evidence against using CEM to determine disease extent in lobular cancer, due to lower conspicuity [54].


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. MRI Breast Without and With IV Contrast MRI breast is useful for detecting additional cancers in the ipsilateral and contralateral breast [16,55], particularly in women with dense breasts [23,56,57]. A meta-analysis of 22 studies investigated MRI screening of the contralateral breast in women with newly diagnosed breast cancer. The study reported contralateral malignancies that were detected by MRI in 131 of 3,253 women. Thus, the summary estimate for incremental cancer detection rate was 4.1%. In studies in which pathologic tumor stage was reported, all but 2 tumors were in situ or stage I, and of those 2 tumors, 1 was a node-negative ILC (42 mm). Summary estimates were as follows: MRI-directed additional biopsy in 9.3% of women (95% CI, 5.8%-14.7%) with PPV for malignancy of 47.9% (95% CI, 31.8%- 64.6%). Where reported, 35.1% of MRI-detected cancers were DCIS (mean size = 6.9 mm) and 64.9% were invasive cancers (mean size = 9.3 mm) [58].


Imaging of Invasive Breast Cancer

Imaging of Invasive Breast Cancer. MRI can accurately assess tumor size for preoperative planning [50,59-61]. In a study involving 343 tumors, size measurements of cancers on breast MRI were within 5 mm of pathological size in 88% of patients [60]. Still, other studies using mastectomy specimens have shown that MRI underestimates primary tumor size in 21% and overestimates primary tumor size in 24% of cases. MRI also overestimated the number of invasive lesions by 19% and underestimated the number of invasive lesions in 28% in the same study [62]. These data underscore the importance of using biopsy to pathologically confirm MRI findings before using them to alter surgical planning, especially when the MRI finding is nonmass enhancement [63].