Sharifi Arghavan, O'Donnell Thomas, Dane Bari
New York University Langone Medical Center, New York, US.
Siemens Healthineers (United States), Malvern, US.
Abdom Radiol (NY). 2025 Feb 12. doi: 10.1007/s00261-025-04832-z.
To determine the optimal virtual monoenergy for viewing the bowel at photon-counting CT enterography using quantitative assessment of mural attenuation, contrast-to-noise ratio, signal-to-noise ratio and noise.
This study was institutional review board approved and Health Insurance Portability and Accountability Act compliant. Consecutive adults (≥ 18 years) who underwent photon-counting CT enterography from 5/1/2022-5/31/2022 with available Spectral Postprocessing (SPP) images for retrospective virtual monoenergy creation were identified. Nine virtual monoenergetic series (40-120 keV, 10 keV increments) were created. Two region-of-interest measurements were placed in the stomach wall, jejunum wall, ileum wall, and each psoas muscle by two radiologists on 0.6 mm images in PACS. Region-of-interests were copied to other virtual monoenergies to ensure identical placement and size. Attenuation (HU) and noise (HU standard deviation) were recorded from each region-of-interest. Signal-to-noise ratio and contrast-to-noise ratio were computed for stomach, jejunum, ileum, and all bowel combined. Pairwise comparisons for attenuation, noise, signal-to-noise ratio and contrast-to-noise ratio for each virtual monoenergy were performed with ANOVA. A p <.05 indicated statistical significance.
50 patients (32 female; mean[SD] age: 57 years) were included. Attenuation and noise for all bowel regions were highest at 40 keV with statistically significant pairwise comparisons from 40 to 70 keV (all p <.05), but similar for 70-120 keV (all p >.05). Signal-to-noise ratio was similar from 40 to 70 keV (all p >.05) for all bowel regions. Contrast-to-noise ratio decreased with increasing keV. Contrast-to-noise ratio was similar for all bowel at 40 keV and 50 keV (p =.06), for stomach from 40 to 70 keV (all p >.05), for jejunum from 40 to 50 keV (p =.21), and for ileum from 40 to 60 keV (all p >.05).
50 keV virtual monoenergetic images from photon-counting CT enterography optimizes contrast-to-noise ratio while mitigating noise and should routinely be utilized for bowel assessment at photon-counting CT enterography. As most photon-counting CT users primarily interpret virtual monoenergetic images in clinical practice, knowledge of the optimal virtual monoenergy can inform protocol development.
通过对肠壁衰减、对比噪声比、信噪比和噪声进行定量评估，确定在光子计数CT小肠造影中观察肠道的最佳虚拟单能量。
本研究经机构审查委员会批准，并符合《健康保险流通与责任法案》。纳入2022年5月1日至2022年5月31日期间接受光子计数CT小肠造影且有可用光谱后处理（SPP）图像用于回顾性创建虚拟单能量的连续成年人（≥18岁）。创建了九个虚拟单能量系列（40 - 120 keV，以10 keV递增）。两名放射科医生在PACS中的0.6 mm图像上，在胃壁、空肠壁、回肠壁和每块腰大肌中放置两个感兴趣区测量。将感兴趣区复制到其他虚拟单能量以确保放置位置和大小相同。记录每个感兴趣区的衰减（HU）和噪声（HU标准差）。计算胃、空肠、回肠以及所有肠道的信噪比和对比噪声比。对每个虚拟单能量的衰减、噪声、信噪比和对比噪声比进行方差分析的成对比较。p <.05表示具有统计学意义。
纳入50例患者（32例女性；平均[标准差]年龄：57岁）。所有肠道区域的衰减和噪声在40 keV时最高，从40 keV到70 keV进行成对比较有统计学意义（所有p <.05），但在70 - 120 keV时相似（所有p >.05）。所有肠道区域在40 keV到70 keV时信噪比相似（所有p >.05）。对比噪声比随keV增加而降低。所有肠道在40 keV和50 keV时对比噪声比相似（p =.06），胃在40 keV到70 keV时相似（所有p >.05），空肠在40 keV到50 keV时相似（p =.21），回肠在40 keV到60 keV时相似（所有p >.05）。
光子计数CT小肠造影的50 keV虚拟单能量图像可优化对比噪声比，同时减轻噪声，应常规用于光子计数CT小肠造影的肠道评估。由于大多数光子计数CT使用者在临床实践中主要解读虚拟单能量图像，了解最佳虚拟单能量可为方案制定提供参考。
