A novel application of CT angiography to detect extracoronary vascular abnormalities in patients with spontaneous coronary artery dissection

Background: Spontaneous coronary artery dissection (SCAD) is associated with extracoronary vascular abnormalities, which depending on type and location may warrant treatment or provide additional diagnostic or prognostic information about this uncommon entity. Fibromuscular dysplasia (FMD), aneurysms, and dissections have been detected in multiple vascular territories by magnetic resonance angiography, CT angiography (CTA), and catheter angiography. The optimal modality to detect extracoronary vascular abnormalities is unknown. We highlight the technique and feasibility of a novel CTA protocol to detect extracoronary vascular abnormalities in these patients, incorporating patient safety and convenience. Methods: The complete CTA protocol consisting of a single CTA of the neck, chest, abdomen, and pelvis was performed on 39 SCAD outpatients. All examinations were performed with 200mL of low-osmolar contrast agent and used radiation dose modulation techniques. Average volume CT dose index was 9mGy for the chest, abdomen, and pelvis portions and 21mGy for the neck portion. Studies were independently reviewed by 2 senior vascular radiologists. Results: Two patients had nondiagnostic CTA neck evaluation because of technical acquisition errors. Extracoronary vascular abnormalities were detected in 27 of 39 patients (69%). Catheter angiography detected brachial artery FMD in 1 patient, a vascular bed not included in the SCAD CTA protocol. Extracoronary vascular abnormalities were common, including FMD, aneurysms, dissection, and aortic tortuosity, and were seen in the iliac (36%), carotid and/or vertebral (31%), splanchnic (10%), and renal (26%) arteries and in the thoracic and/or abdominal aorta (10%). Conclusions: The frequency of extracoronary vascular abnormalities and extent of territories identified the CTA protocol in our cohort are high. A tailored CTA may be the optimal imaging technique for detecting extracoronary vascular abnormalities in patientswith suspected underlying vasculopathy. Although the clinical significance of extracoronary vascular abnormalities remains unclear, detection of these abnormalities has identified patients in whom cerebral imaging and serial monitoring have been recommended.