First-generation Photon-counting Computed Tomography Angiography Versus Third-generation Dual-energy Computed...

To investigate the objective performance and subjective image quality of lower extremity CT angiography (CTA) in peripheral artery disease (PAD) through comparison of the first-generation photon-counting CT (PCCT) technology and the third-generation dual source energy-integrating detector CT (DECT) technology.

Patients who underwent a CTA either on a PCCT or on a DECT were included in this retrospective analysis. All included patients received a digital subtraction angiography (DSA) as reference standard for stenosis grading. Virtual monoenergetic image data sets were reconstructed at 40, 45, 50, 55, and 60 keV. The noise, the signal-to-noise ratio (SNR), and the contrast-to-noise ratio (CNR) of vascular structures, as well as the subjective image quality using a standardized 5-point Likert Scale, were determined. Finally, the sensitivity, specificity, and accuracy of the stenotic disease detection for either technology (DECT and PCCT) were analyzed.

PCCT angiography was performed in 50 PAD patients (31 males, mean age 76.16 ± 10.26), and DECT angiography was pursued in 50 PAD patients as well (29 males, mean age 74.0 ± 14.26). PCCT reached significantly higher CNR compared with DECT in all assessed arterial territories [eg, 27.84 (IQR: 22.57 to 34.66) vs 17.25 (IQR: 12.12 to 23.71), at the iliac arterial vasculature at 40 keV, P < 0.001]. Image quality and contrast were rated significantly higher for PCCT compared with DECT [eg, mean vessel contrast 5 (IQR: 4 to 5) vs 4 (IQR: 4 to 4)], at the calf arterial vasculature at 40 keV, P <0.001. Overall sensitivity, specificity, and accuracy for PCCT were 96%, 97%, and 97%, respectively, in comparison to 93%, 96%, and 94%, respectively, for DECT image data sets at 55 keV.

PCCT offers superior objective performance and better subjective image quality compared with DECT. Hence, PCCT angiography is improving cross-sectional PAD imaging.