Radiol Med. 2026 Jul 13. doi: 10.1007/s11547-026-02260-7. Online ahead of print.
ABSTRACT
PURPOSE: Clinical application of late iodine enhancement (LIE) for myocardial scar identification is limited by low contrast-to-noise ratio (CNR). Photon-counting detector-CT (PCD-CT) can improve image quality providing spectral information and low image noise. The aim of the study was to assess the impact of spectral analysis and reconstruction parameters on LIE image quality using PCD-CT.
MATERIAL AND METHODS: This single-center retrospective study included 74 patients undergoing PCD-CT between May 2024 and July 2025 for myocardial scar evaluation. Images from patients with visible LIE were reconstructed using four parameter combinations (Qr40 and Qr36 kernels; 0.4-mm and 2-mm slice thickness) and analyzed at monoenergetic levels (40-120 keV, 10 keV increment) using a dedicated workstation. CNR and signal-to-noise ratio (SNR) were calculated for each reconstruction.
RESULTS: Among 74 patients, 41 (55%) had myocardial scar (M:F 32:9; 62 years [IQR,56-71]) and 24/41 (59%) had an implantable cardioverter defibrillator (ICD). Scars were predominantly transmural (21/41, 51%). A 40-keV VMI achieved the highest CNR and SNR, regardless of reconstruction parameters (p < 0.05), with median CNR of 5.36 [IQR, 4.07-6.88] using 2-mm slice thickness and Qr36 kernel. Scar pattern, ICD, and BMI did not significantly affect either CNR or SNR (p > 0.05). In the exploratory subgroup of 16 patients undergoing LGE-MRI, CNR is not statistically different between LIE-CT at 40 keV with 2-mm slice thickness from LGE-MRI (5.36 [IQR,4.07-6.88] vs. 8.04 [IQR,6.67-9.89]; p = 0.178).
CONCLUSION: PCD-CT LIE demonstrated the highest CNR at 40-keV VMI with 2-mm slice thickness, regardless of scar pattern, BMI, or ICD presence.
PMID:42440227 | DOI:10.1007/s11547-026-02260-7
