Kokawa Takanori, Nakamura Satoshi, Takafuji Masafumi, Yamazaki Akio, Sakuma Hajime, Kitagawa Kakuya
Department of Radiology, Mie University Hospital, Tsu, Japan.
Department of Advanced Diagnostic Imaging, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu, Mie, 514-8507, Japan.
Int J Cardiovasc Imaging. 2025 Jun 5. doi: 10.1007/s10554-025-03437-3.
Photon-counting detector CT (PCD-CT) holds promise for cardiac CT imaging, including the measurement of extracellular volume (ECV), due to its advanced imaging capabilities. The study aimed to compare the protocols with and without additional contrast medium after coronary CT angiography (CCTA) by evaluating (1) the stability of subtraction method-based ECV (ECV) across various keV images and (2) the correlation and agreement of ECV with iodine map-based ECV (ECV). Forty patients with known or suspected coronary artery disease were divided into two groups. In Protocol A (n = 20), only the standard contrast dose for CCTA was administered, while in Protocol B (n = 20), additional contrast medium was given after CCTA. The difference between the largest and smallest ECV among multiple keV images was defined as the variability of ECV. Correlations and agreement between the methods were assessed using Pearson's correlation coefficient (r), intraclass correlation coefficient (ICC), and Bland-Altman analyses. The mean variability in ECV was significantly higher in Protocol A (3.8 ± 2.1) compared to Protocol B (2.1 ± 0.9) (p = 0.008). In Protocol A, the correlation between ECV and ECV was poor (r = 0.43, p = 0.059) with a low ICC of 0.40. In this group, Bland-Altman analysis showed a mean difference of 3.7 and limits of agreement from -9.4 to 16.8. In Protocol B, a stronger correlation was observed (r = 0.74, p < 0.001) with an ICC of 0.68. In this group, the mean difference was 2.8 with narrower limits of agreement (-4.8 to 10.4). Additional contrast medium is essential for stable myocardial ECV measurements using PCD-CT.
光子计数探测器CT（PCD-CT）因其先进的成像能力，在心脏CT成像方面具有前景，包括细胞外容积（ECV）的测量。本研究旨在通过评估（1）基于减法方法的ECV（ECV）在不同keV图像上的稳定性，以及（2）ECV与基于碘图的ECV（ECV）的相关性和一致性，比较冠状动脉CT血管造影（CCTA）后使用和不使用额外造影剂的方案。40例已知或疑似冠状动脉疾病的患者被分为两组。在方案A（n = 20）中，仅给予CCTA的标准造影剂剂量，而在方案B（n = 20）中，CCTA后给予额外的造影剂。多个keV图像中最大和最小ECV之间的差异被定义为ECV的变异性。使用Pearson相关系数（r）、组内相关系数（ICC）和Bland-Altman分析评估两种方法之间的相关性和一致性。与方案B（2.1±0.9）相比，方案A中ECV的平均变异性显著更高（3.8±2.1）（p = 0.008）。在方案A中，ECV与ECV之间的相关性较差（r = 0.43，p = 0.059），ICC较低，为0.40。在该组中，Bland-Altman分析显示平均差异为3.7，一致性界限为-9.4至16.8。在方案B中，观察到更强的相关性（r = 0.74，p < 0.001），ICC为0.68。在该组中，平均差异为2.8，一致性界限更窄（-4.8至10.4）。使用PCD-CT进行稳定的心肌ECV测量时，额外的造影剂至关重要。
