• Coronary Artery Disease
• Energy Integrating Detector
• Photon Counting Detector

BACKGROUND. Photon-counting detector-computed tomography (PCD-CT) represents the state-of-the-art technology in coronary CT angiography (cCTA) for the diagnosis of coronary artery disease (CAD).
OBJECTIVES. This study aim to quantifying the clinical advantages and diagnostic performance of PCD-CT compared to conventional energy-integrating detector computed tomography (EID-CT) for obstructive CAD.
MATERIAL AND METHODS. we retrospectively evaluated consecutive patients referred to invasive coronary angiography (ICA) after an identification of significant CAD at cCTA: 60 underwent cCTA with a conventional EID-CT (TOSHIBA Aquilion One 320) and 60 with a PCD-CT (Photon Counting NAEOTON Alpha, Siemens Healthiness). The diagnostic performance of EID-CT and PCD-CT for the identification of the presence and extent of a stenosis in 16 coronary artery segments for each patient, was compared using ICA as gold standard.
RESULTS. In the vessel level analysis, PCD-CT demonstrated an improved sensitivity (92% vs 68%), specificity (99% vs 97%), AUC (area under the curve, 0.96 vs 0.82, p=<0.0001), positive predict value (PPV, 93% vs 79%), negative predict value (NPV, 99% vs 95%) and overall diagnostic accuracy (98% vs 93%) compared to EID-CT. The increase of PPV with PCD-CT was confirmed also in coronary segments with previous stent.
CONCLUSIONS. The improved spatial and temporal resolution, the reduction of signal noise and the overall capacity to minimize motion, metal and calcium blooming artifact allow PCD-CT to achieve an excellent and overall better diagnostic performance for detecting obstructive CAD compared to EID-CT.