Duplex ultrasound interpretation criteria for inferior mesenteric arteries.

There is no specific duplex ultrasound (DUS) criteria for the diagnosis of inferior mesenteric artery (IMA) stenosis. This study will define the optimal duplex velocity values with the best overall accuracy (OA) in detecting ≥50% stenosis of the IMAs. Eighty-five IMAs with both DUS and mesenteric arteriography were analyzed. Eighty-five IMAs were examined: 45 were normal, 12 with <50% stenosis, eight with ≥50-69% stenosis and 15 with ≥70% stenosis (including occlusion) based on angiography. The mean peak systolic velocities (PSVs) for a normal IMA, <50% and ≥50% stenosis was 105, 215 and 392 cm/second, respectively (P < 0.0001). The most accurate PSV in detecting ≥50% stenosis was ≥250 cm/second with a sensitivity of 90%, a specificity of 96% and an OA of 95%. The most accurate end-diastolic velocity (EDV) in detecting ≥50% stenosis was ≥80% or ≥90 cm/second, with an OA of 86%, a sensitivity of 60% and a specificity of 100%. The most accurate ratio in detecting ≥50% stenosis was ≥4 or ≥4.5 with an OA of 93%.Receiver operator curves analysis showed that the PSV was not better than EDV and PSV ratio in detecting ≥50% stenosis (P = 0.1661 and 0.4568, respectively). In conclusion, specific IMA PSVs, EDVs and IMA/aortic systolic ratios can be used in detecting significant IMA stenosis with reasonable accuracy.