According to a new study appearing in the American Journal of Roentgenology (AJR), use of photon-counting detector (PCD) CT may improve vascular evaluation in patients with peripheral arterial disease.

“PCD CTA yielded multiple advantages relative to energy-integrating detector (EID) CTA for visualizing small infrapopliteal vessels and characterizing associated plaque,” writes corresponding author Prabhakar Shantha Rajiah, MBBS, MD, a cardiovascular radiologist at Mayo Clinic in Rochester, Minn.

This AJR-accepted manuscript included 32 patients (mean age 69.5 years; 27 men, 5 women) who underwent clinically indicated lower-extremity EID CTA between April 2021 and March 2022; participants underwent investigational lower-extremity PCD CTA later in the same day as EID CTA using a reduced IV contrast media dose.

Two radiologists independently reviewed examinations in two sessions—each containing a random combination of EID-CT and PCD-CT examinations—assessing the number of visualized fibular perforators, characteristics of stenoses at 11 infrapopliteal segmental levels, and subjective arterial sharpness. 

Ultimately, compared with EID CTA, PCD CTA yielded more visualized fibular perforators (reader 1: 6.4±3.2 vs. 4.2±2.4, p <.001; reader 2: 8.8±3.4 vs. 7.6±3.3, p =.04), greater confidence in assessing stenosis for reader 1 (82.3±20.3 vs. 78.0±20.2, p <.001), and lower number of segments with total occlusion for reader 2 (0.5±1.3 vs 0.9±1.7, p =.04).