Accuracy of Low-Dose CT Angiography for In-Stent Restenosis Assessment in Iliac Arteries

This phantom study used a physical model of iliac artery stent stenoses to assess whether low-dose CT angiography protocols could accurately characterize in-stent restenosis while reducing radiation exposure.

Low-dose CT angiography maintained accuracy within 12% for simulated stenoses compared with standard-dose protocols, with less than 6% variation between dose levels. The results suggest that radiation dose can be meaningfully reduced without proportionate loss of stenosis measurement accuracy in the iliac artery model.

The phantom design is the defining limitation: physical phantoms accurately reproduce X-ray attenuation properties of specific materials but cannot replicate patient body habitus variability, cardiac motion, respiratory motion, or calcification heterogeneity. Results from phantom studies must be validated in clinical populations before influencing practice.

Peripheral vascular CT angiography is an important clinical tool for evaluating iliac and lower-extremity stenosis, and dose optimization in any modality used serially in patients with PAD is a reasonable goal. This study contributes technical data but is too early-stage to affect clinical protocols.

We rate the evidence limited. A small phantom study on low-dose CT angiography accuracy for iliac stent restenosis — technical rather than clinical evidence, requiring human validation.