ARRS Case of the Week- Apr 30, 2018

CARDIOVASCULAR IMAGING: Thoracic Arteries

Case Author: Diana Litmanovich, MD, Beth Israel Deaconess Medical Center

History

89-year-old man with chest pain.

Imaging Findings

MDCT angiogram of the chest (A) shows a large, irregular soft-tissue filling defect along the posterior aspect of the distal aortic arch that protrudes into the lumen. Coronal (B) and sagittal (C) reformatted CT images show extension of the filling defect into the proximal descending aorta and calcification of the aortic wall.

Diagnosis

Atheroma

Teaching Points

Extensive aortic wall calcification in association with mural or endoluminal filling defects of soft-tissue attenuation are highly suggestive of advanced atherosclerosis with extensive atheromatous formation. Severe atheroma of the aortic arch is an important risk factor and mechanism for stroke and peripheral embolism. The prevalence of aortic arch atheroma is 20% among patients with acute ischemic stroke.

Unlike atheroma, angiosarcoma and intimal sarcoma are not necessarily associated with mural calcifications and occur in a relatively younger population. Both CT and MRI show an enhancing irregular soft-tissue mass when sarcoma is present. The mass may extend beyond the aortic wall into the adjacent structures.

MRI and PET/CT can be used to differentiate atheroma from intimal sarcoma. Unlike atheroma, intimal sarcoma exhibits contrast enhancement and avid FDG uptake. Intimal sarcoma is commonly associated with thrombus formation along the length of the lesion and may be a source of distal emboli.

Atheroma extends from the intima into the lumen, unlike penetrating atherosclerotic ulcer, which is focal ulceration of an atherosclerotic plaque penetrating the aortic intima into the aortic wall. Atheroma can be located anywhere in the descending and abdominal aorta, but the superior wall of the distal aortic arch at its junction with the proximal descending aorta is a common location. Penetrating atherosclerotic ulcer is usually located in the mid to distal third of the descending aorta.

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