First clinical experience with the NAEOTOM Alpha.Peak photon-counting CT: high diagnostic reliability and ultra-low-dose CCTA in routine practice

Abstract

The NAEOTOM Alpha.Peak represents the next generation of photon-counting computed tomography (PCCT) and currently the most advanced CT technology worldwide. Owing to its superior spatial resolution and spectral differentiation capability, it is particularly well suited for the detection and quantification of coronary plaques, providing new opportunities for early diagnosis and prevention of coronary artery disease (CAD). The first two systems were delivered on June 23, 2025. This analysis aimed to report our initial clinical experience with the implementation and routine use of the NAEOTOM Alpha.Peak PCCT system, focusing on coronary computed angiography (CCTA) scan protocols, and radiation exposure. This analysis included all consecutive patients who underwent CCTA using the NAEOTOM Alpha.Peak after completion of the implementation and protocol optimization phase (June 30 to July 31, 2025) at our German outpatient center. Data were evaluated with respect to the applied scan protocols and radiation exposure. Between August 1, 2025, and January 30, 2026, a total of 2,699 patients underwent CCTA using the NAEOTOM Alpha.Peak (64% male; median age 65.3 years). In 23.0% of cases, coronary plaques or stenoses could be excluded. The mean examination volume was 21.6 scans per day, with a peak throughput of up to 30 scans per day. In 2,580 patients (95.6%), diagnostic image quality was achieved with the initial acquisition. Among patients with diagnostic image quality achieved in the first acquisition (n = 2,580), axial acquisition with prospective triggering (“Sequential” mode) remained the predominant protocol (1,880 patients; 72.9%), with a median contrast volume of 57 mL (IQR 0) and a median effective dose of 2.7 mSv (IQR 1.2 mSv). The lowest median contrast volume and radiation dose were observed with the high-pitch helical “FLASH” mode (47 mL [IQR 0]; 1.05 mSv [IQR 0.42]; each p < 0.001), applied in 350 patients (13.6%). Retrospectively gated low-pitch helical acquisition (“Spiral” mode) was used in 349 patients (13.5%), with a median contrast volume of 57 mL (IQR 2) and a median effective dose of 3.36 mSv (IQR 1.81). UHR mode was rarely required for clinical decision-making and was associated with higher radiation exposure (median effective dose 4.63 mSv; contrast volume 57 mL). In patients with prior PCI, prospective sequential acquisition was predominantly used (90.9%), whereas in patients after coronary artery bypass grafting, high-pitch “FLASH” mode was most frequently applied (74.1%). The NAEOTOM Alpha.Peak demonstrated excellent image quality at remarkably low radiation doses in routine clinical use. Even during the early implementation phase, the system achieved high diagnostic reliability and efficiency in CCTA. These findings highlight the strong potential of PCCT technology to advance noninvasive coronary imaging and preventive cardiology.