Imaging Pearls ❯ Vascular ❯ Subclavian Artery
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- “As with all arteries, the subclavian artery can be involved in a spectrum of abnormalities. The abnormal subclavian artery can manifest with various imaging findings including stenosis, occlusion, aneurysm, pseudoaneurysm, transection, and mural inflammation. The underlying cause of these abnormalities is also variable and includes atherosclerosis, inflammatory and noninflammatory vasculopathies,and trauma. The subclavian artery can also be secondarily involved in processes centered elsewhere, particularly when it serves as a collateral pathway. Recognition of involvement of the subclavian artery in these conditions facilitates understanding of the CT examination and can aid in differential diagnosis, when necessary.”
Subclavian Artery: Anatomic Review and Imaging Evaluation of Abnormalities
Caroline L. Robb, Sanjeev Bhalla, Constantine A. Raptis
RadioGraphics 2022; 42:0000–0000 - “The right subclavian artery usually branches from the right brachiocephalic artery, which arises as the first branch vessel from a left aortic arch. The left subclavian artery usually arises as the third and final arch branch vessel. There is some variability in the configuration of the aortic arch in patients with normal branching patterns. Most notably, in patients with a bicuspid aortic valve, the left subclavian artery may have a more vertical orientation, and the distance between the origins of the left common carotid and left subclavian arteries may be increased.”
Subclavian Artery: Anatomic Review and Imaging Evaluation ofAbnormalities
Caroline L. Robb, Sanjeev Bhalla, Constantine A. Raptis
RadioGraphics 2022; 42:0000–0000 - “The aberrant right subclavian artery arises as the last arch branch and takes a retroesophageal course. Although most patients are asymptomatic, esophageal compression causes dysphagia, which is termed dysphagia lusoria, in approximately 10% of patients. In 15%–30% of cases, a retroesophageal outpouching, which is termed a diverticulum of Kommerell, is seen at the origin of the aberrant right subclavian artery. A diverticulum of Kommerell is thoughtto be related to the component of the primordialarch that forms the right-sided ductus arteriosus and is a strong predictor that the ligamentum arteriosum is on the contralateral side of the arch,thereby completing a loose vascular ring.”
Subclavian Artery: Anatomic Review and Imaging Evaluation ofAbnormalities
Caroline L. Robb, Sanjeev Bhalla, Constantine A. Raptis
RadioGraphics 2022; 42:0000–0000 - “Imaging includes MRI or CT angiography performed with the patient’s arm positioned by their side and in a raised position. CT and MRI show subclavian artery narrowing that worsens with arm abduction in many patients with arterial TOS. However, this finding is not exclusively sufficient for diagnosis, as many patients without clinical TOS have similar imaging findings. More important imaging findings include those of vascular damage, specifically, a subclavian artery aneurysm or pseudoaneurysm, thrombosis that is not due to atherosclerosis atthe site of compression, a fixed stenosis, or anembolism.”
Subclavian Artery: Anatomic Review and Imaging Evaluation of Abnormalities
Caroline L. Robb, Sanjeev Bhalla, Constantine A. Raptis
RadioGraphics 2022; 42:0000–0000 - “The most commonly involved vessel is the vertebral artery. When the vertebral artery is involved, vertebrobasilar insufficiency may result from reversal of blood flow from the intracranial circulation to reconstitute the occluded subclavian artery. The diagnosis can be suggested when a focal upstream stenosis is seen in the subclavian artery in a patient with appropriate symptoms. Reversal of vertebral artery flow at Doppler US or phase-contrast MRI allows confirmation of the diagnosis.”
Subclavian Artery: Anatomic Review and Imaging Evaluation of Abnormalities
Caroline L. Robb, Sanjeev Bhalla, Constantine A. Raptis
RadioGraphics 2022; 42:0000–0000 - “Takayasu arteritis has a propensity to involve the subclavian arteries and may result in a nonpalpable brachial pulse or asymmetric blood pressure in the upper extremities, hence the moniker “pulseless arteritis” Giant cell arteritis, on the other hand, is known as temporal arteritis, given the frequent involvement of the temporal artery. Patients with giant cell arteritis may present with headache, jaw pain, unexplained fever, or visual disturbances. In many cases, distinguishing between Takayasu arteritis and giant cell arteritis is not possible at imaging or on the basis of clinical grounds. In these cases, patients younger than 50 years with large vessel vasculitis are considered to have Takayasu arteritis, while those older than 50 years are described as having giant cell arteritis.”
Subclavian Artery: Anatomic Review and Imaging Evaluation of Abnormalities
Caroline L. Robb, Sanjeev Bhalla, Constantine A. Raptis
RadioGraphics 2022; 42:0000–0000 - “The subclavian artery is an important structure that may be involved in a variety of abnormalities, may serve as a collateral vessel, or may have a role in a range of vascular procedures. Familiarity with normal and variant anatomy and expected postprocedural findings provides a foundation for determining if the imaging appearance is within normal limits and helps the radiologist to distinguish a true subclavian artery abnormality from potential mimics. Knowledge of subclavian artery abnormalities also helps to narrow the differential diagnosis and ultimately directly affects patient care and outcomes.”
Subclavian Artery: Anatomic Review and Imaging Evaluation of Abnormalities
Caroline L. Robb, Sanjeev Bhalla, Constantine A. Raptis
RadioGraphics 2022; 42:0000–0000
- “SCA thrombosis can be acute or chronic ; chronic SCA thrombosis is more common than acute SCA thrombosis. Chronic stenosis or thrombosis of the left SCA is four times more common than of the right SCA. The increased incidence of chronic stenosis or thrombosis of the left SCA is theorized to be because of the slightly more acute angulation of the left SCA, which results in turbulent blood flow. Patients with acute thrombosis may experience pain, cold- ness, pallor, and decreased or absent brachial pulses. Thrombectomy or thrombolysis is typically performed to prevent critical limb ischemia.”
Nontraumatic Subclavian Artery Abnormalities: Spectrum of MDCT Findings Jones CS, Verde F, Johnson PT, Fishman EK. AJR Am J Roentgenol. 2016 May 17:1-8 - “TOS is a general term that refers to the symptoms related to pathologic compression of the neurovascular bundle supplying the up- per extremity [6]. TOS is typically subdivided into neurogenic TOS, which refers to compres- sion of the brachial plexus; arterial TOS, which refers to SCA compression; or venous TOS, which refers to subclavian vein compression.”
Nontraumatic Subclavian Artery Abnormalities: Spectrum of MDCT Findings Jones CS, Verde F, Johnson PT, Fishman EK. AJR Am J Roentgenol. 2016 May 17:1-8 - “More than 90% of cases of TOS are neu- rogenic TOS, and the vascular subtypes com- prise the remaining 10% of cases. Arterial TOS is the least common of the three entities, with an estimated incidence of less than 1% of the cases of TOS. Thus, most patients pre- senting with TOS symptoms of arm pain and paresthesia will have neurogenic TOS.”
Nontraumatic Subclavian Artery Abnormalities: Spectrum of MDCT Findings Jones CS, Verde F, Johnson PT, Fishman EK. AJR Am J Roentgenol. 2016 May 17:1-8 - “The SCAs are paired arteries that supply blood to the upper extremities and also give rise to branch vessels including the vertebral artery, internal thoracic artery, thyrocervical trunk, costocervical trunk, and dorsal scapular artery. The right SCA arises as a bifurcation of the right brachiocephalic artery along with the right common carotid artery. The left SCA arises directly from the aortic arch. Anatomically, the SCAs end at the lateral border of the first rib where they become the axillary arteries.”
Nontraumatic Subclavian Artery Abnormalities: Spectrum of MDCT Findings Jones CS, Verde F, Johnson PT, Fishman EK. AJR Am J Roentgenol. 2016 May 17:1-8 - “Isolated SCA dissection is uncommon. Most cases are associated with arterial TOS, connective tissue disease, blunt trauma, or an iatrogenic cause, such as in the setting of arterial catheterization. Rarely, there have been case reports of an isolated SCA dissection with only minimal or no trauma and with no history of catheterization or connective tissue disease.”
Nontraumatic Subclavian Artery Abnormalities: Spectrum of MDCT Findings Jones CS, Verde F, Johnson PT, Fishman EK. AJR Am J Roentgenol. 2016 May 17:1-8 - “The SCAs are commonly involved in large-vessel arteritis such as Takayasu arteritis (TA) and giant cell arteritis (GCA). Both of these entities are characterized by immune-mediated arterial wall inflammation typically involving T cells, antigen presenting cells, and macrophages. Given the similar histopathology of these two entities, it is not surprising that they also have similar manifestations on MDCT. The imaging features typically include arterial wall thickening and stenosis, thrombosis, and occasionally aneurysm formation in the aorta and its primary or secondary branch vessels.”
Nontraumatic Subclavian Artery Abnormalities: Spectrum of MDCT Findings Jones CS, Verde F, Johnson PT, Fishman EK. AJR Am J Roentgenol. 2016 May 17:1-8 - “Thrombosis of the SCAs may be seen on imaging performed of patients with specific symptoms but is also commonly seen incidentally on imaging performed for other indications. The most common causes of SCA thrombosis are progressive atherosclerosis, vessel injury (including vasculitides), and a hypercoagulable state. Thrombosis due to thromboembolic disease or to arterial TOS is relatively rare.”
Nontraumatic Subclavian Artery Abnormalities: Spectrum of MDCT Findings Jones CS, Verde F, Johnson PT, Fishman EK. AJR Am J Roentgenol. 2016 May 17:1-8