CT Angiography of Suspected Peripheral Artery Disease: Comparison of Contrast Enhancement in the Lower Extremities of Patients Undergoing and Those Not Undergoing Hemodialysis.

OBJECTIVE: The objective of our study was to compare contrast enhancement on CT angiography (CTA) images of the lower extremity in patients with suspected peripheral artery disease who did not undergo hemodialysis (HD) and patients who were scanned before or after HD.

MATERIALS AND METHODS: We divided 287 consecutive patients who underwent CTA of the lower extremity on a 64-MDCT scanner into three groups: group 1 patients (n = 151) were not dependent on HD, group 2 patients (n = 70) were dependent on HD and underwent HD less than 24 hours after CTA, and group 3 (n = 66) were dependent on HD and underwent HD less than 24 hours before CTA. We then compared the CT number in the popliteal artery at the level of the patella on all CTA images. A cardiologist and a radiology technologist visually evaluated the depiction of the descending genicular artery (DGA) on the CTA images and assigned a visualization score.

RESULTS: The median CT number was lowest in group 2 patients (373 HU vs 429 [group 1] and 418 [group 3] HU). The score for visualization of the DGA was significantly lower in group 2 than in group 1 (p = 0.02) and group 3 (p = 0.04).

CONCLUSION: At CTA, arterial enhancement decreases with the passage of time after HD likely because of the increase in intravascular volume. CTA that is performed within 24 hours after HD generates higher-quality images of the lower extremities than CTA that is performed within 24 hours before HD.