Multi–Detector Row CT Angiography of Lower Extremity Arterial Inflow and Runoff: Initial Experience

TLDR

The arteries of lower extremity inflow and runoff can be reliably depicted with minimal venous enhancement using multi‑detector row CT. To assess patterns of lower extremity arterial inflow and runoff opacification with four‑channel multi‑detector row CT angiography in patients with symptomatic lower extremity arterial disease. Four‑channel multi‑detector row CT was performed from the supraceliac aorta to the feet with 2.5‑mm nominal detector width, pitch 6.0, 174–185 mL iodinated contrast, a 66‑second scan covering ~1,233 mm, yielding 908 transverse reconstructions and attenuation measurements at 16 arterial and 16 venous sites. All 504 arterial segments were visualized and analyzable, with mean arterial attenuation ranging 253–357 HU and venous enhancement peaking at 99 HU in the saphenous vein, confirming reliable depiction of lower extremity arteries with minimal venous enhancement.

Abstract

To assess the patterns of lower extremity arterial inflow and runoff opacification with four-channel multi-detector row computed tomographic (CT) angiography in a cohort of patients with disease warranting imaging of the lower extremity arterial system.Twenty-four patients with symptomatic lower extremity arterial occlusive or aneurysmal disease underwent imaging with four-channel multi-detector row CT from the supraceliac abdominal aorta through the feet. Transverse sections were acquired with a 2.5-mm nominal detector width and pitch of 6.0 (3.2-mm effective section thickness) following intravenous injection of 174-185 mL of iodinated contrast medium (300 mg iodine per milliliter). In each patient, attenuation measurements were recorded in 16 arterial and 16 venous locations. In 18 patients, two radiologists assessed the detectability and stenosis degree of 21 arterial segments per patient relative to these features at conventional angiography.A mean scanning time of 66 seconds was required to cover a mean of 1,233 mm, resulting in a mean of 908 transverse reconstructions. All 504 arterial segments were depicted and analyzable. Mean arterial attenuation ranged from 253 HU in the midabdominal aorta to 357 HU in the popliteal artery and 253 HU in the dorsalis pedis or posterior tibial artery measured inferior to the tibiotalar joint. Maximum mean venous enhancement (99 HU) was observed in the saphenous vein at the ankle, with all other venous stations measuring less than 74 HU.The arteries of lower extremity inflow and runoff can be reliably depicted with minimal venous enhancement by using multi-detector row CT.