Delivering the Saline Chaser Via a Spiral Flow-Generating Tube Improves Arterial Enhancement for Computed Tomography Angiography of the Lower Extremities.

We delivered the saline chaser via a spiral flow-generating tube or a conventional connecting tube and compared arterial enhancement at computed tomography angiography (CTA) of the lower extremities.We randomly assigned 100 patients whose ankle bronchial pressure index or clinical symptoms were suspect of peripheral arterial disease to a spiral flow-generating tube (protocol A) or a conventional connecting-tube protocol (protocol B) and performed CTA of the lower extremities. The test bolus was delivered under protocol A or B, and the CT numbers recorded for each protocol were compared. Two radiological technologists visually evaluated the descending genicular artery.In the test injection, the median CT number for the popliteal artery was significantly higher with protocol A than B (204.5 HU vs. 170.5 HU, P = 0.03). For CTA of the lower extremities, the median CT number for the popliteal artery at the level of the patella was 436.1 HU (range, 259-608 HU) under protocol A; with protocol B, it was 382.9 HU (range, 244-564 HU) (P = 0.02). The visual score assigned in the descending genicular artery was statistically significantly higher under protocol A than B (P = 0.03).Use of the spiral flow-generating tube increased the effect of the saline chaser and significantly improved arterial enhancement from the abdominal aorta to the arteries of the foot at CTA of the lower extremities.