Dane Bari, Ruff Andrew, O'Donnell Thomas, El-Ali Alexander, Ginocchio Luke, Prabhu Vinay, Megibow Alec
From the Department of Radiology, NYU Langone Health, NYU Grossman School of Medicine, New York, NY.
Siemens Healthineers, Malvern, PA.
J Comput Assist Tomogr. 2024;48(2):251-256. doi: 10.1097/RCT.0000000000001562. Epub 2023 Nov 17.
This study aimed to compare the image quality of portal venous phase-derived virtual noncontrast (VNC) images from photon-counting computed tomography (PCCT) with energy-integrating dual-energy computed tomography (EI-DECT) in the same patient using quantitative and qualitative analyses.
Consecutive patients retrospectively identified with available portal venous phase-derived VNC images from both PCCT and EI-DECT were included. Patients without available VNC in picture archiving and communication system in PCCT or prior EI-DECT and non-portal venous phase acquisitions were excluded. Three fellowship-trained radiologists blinded to VNC source qualitatively assessed VNC images on a 5-point scale for overall image quality, image noise, small structure delineation, noise texture, artifacts, and degree of iodine removal. Quantitative assessment used region-of-interest measurements within the aorta at 4 standard locations, both psoas muscles, both renal cortices, spleen, retroperitoneal fat, and inferior vena cava. Attenuation (Hounsfield unit), quantitative noise (Hounsfield unit SD), contrast-to-noise ratio (CNR) (CNR vascular , CNR kidney , CNR spleen , CNR fat ), signal-to-noise ratio (SNR) (SNR vascular , SNR kidney , SNR spleen , SNR fat ), and radiation dose were compared between PCCT and EI-DECT with the Wilcoxon signed rank test. A P < 0.05 indicated statistical significance.
A total of 74 patients (27 men; mean ± SD age, 63 ± 13 years) were included. Computed tomography dose index volumes for PCCT and EI-DECT were 9.2 ± 3.5 mGy and 9.4 ± 9.0 mGy, respectively ( P = 0.06). Qualitatively, PCCT VNC images had better overall image quality, image noise, small structure delineation, noise texture, and fewer artifacts (all P < 0.00001). Virtual noncontrast images from PCCT had lower attenuation (all P < 0.05), noise ( P = 0.006), and higher CNR ( P < 0.0001-0.04). Contrast-enhanced structures had lower SNR on PCCT ( P = 0.001, 0.002), reflecting greater contrast removal. The SNRfat (nonenhancing) was higher for PCCT than EI-DECT ( P < 0.00001).
Virtual noncontrast images from PCCT had improved image quality, lower noise, improved CNR and SNR compared with those derived from EI-DECT.
本研究旨在通过定量和定性分析，比较同一患者在光子计数计算机断层扫描（PCCT）和能量积分双能计算机断层扫描（EI-DECT）中门静脉期衍生的虚拟平扫（VNC）图像的图像质量。
纳入连续的患者，这些患者回顾性地确定有来自PCCT和EI-DECT的可用门静脉期衍生VNC图像。排除在PCCT的图像存档和通信系统中没有可用VNC图像、之前没有EI-DECT图像以及非门静脉期采集图像的患者。三位经过专科培训且对VNC来源不知情的放射科医生对VNC图像进行5分制的定性评估，评估内容包括整体图像质量、图像噪声、小结构描绘、噪声纹理、伪影以及碘去除程度。定量评估使用在主动脉4个标准位置、双侧腰大肌、双侧肾皮质、脾脏、腹膜后脂肪和下腔静脉内的感兴趣区测量。采用Wilcoxon符号秩检验比较PCCT和EI-DECT之间的衰减（亨氏单位）、定量噪声（亨氏单位标准差）、对比噪声比（CNR）（CNR血管、CNR肾脏、CNR脾脏、CNR脂肪）、信噪比（SNR）（SNR血管、SNR肾脏、SNR脾脏、SNR脂肪）以及辐射剂量。P < 0.05表示具有统计学意义。
共纳入74例患者（27例男性；平均±标准差年龄，63 ± 13岁）。PCCT和EI-DECT的计算机断层扫描剂量指数体积分别为9.2 ± 3.5 mGy和9.4 ± 9.0 mGy（P = 0.06）。定性方面，PCCT的VNC图像在整体图像质量、图像噪声、小结构描绘、噪声纹理以及伪影方面表现更好（所有P < 0.00001）。PCCT的虚拟平扫图像具有更低的衰减（所有P < 0.05）、噪声（P = 0.006）以及更高的CNR（P < 0.0001 - 0.04）。PCCT上增强结构的SNR较低（P = 0.001，0.002），这反映出对比度去除更多。PCCT的SNR脂肪（非增强）高于EI-DECT（P < 0.00001）。
与EI-DECT衍生的图像相比，PCCT的虚拟平扫图像具有更好的图像质量、更低的噪声、更高的CNR和SNR。
