Mikić Manon, Lietz Philipp, Dierig Julie-Ann, Meller Sebastian, Pees Michael, Merhof Kristina
Clinic for Small Animals, University of Veterinary Medicine, Hannover, Germany.
Department of Small Mammal, Reptile and Avian Medicine and Surgery, University of Veterinary Medicine, Hannover, Germany.
Front Vet Sci. 2025 Mar 13;12:1521986. doi: 10.3389/fvets.2025.1521986. eCollection 2025.
Spectral detector Computed Tomography (SDCT) enables generation of virtual non-contrast (VNC) images derived from a post-contrast scan, as previously investigated in healthy dogs. This technique is especially promising for awake scanned rabbits where motion between the pre- and the post-contrast scans makes comparison challenging. This study aimed to determine the reliability of VNC images for assessing abdominal organs in 20 rabbits by evaluating their qualitative and quantitative parameters compared to true unenhanced (TUE) images. Our hypothesis were that the VNC series would be comparable to TUE series and that the quality of the VNC images would be equal to or even superior to the native images.
Attenuation values of VNC and TUE series were assessed using a two one-sided t-test (TOST) and the signal-to-noise ratio was calculated for each ROI in the different series. Additionally, a qualitative assessment of the VNC images relative to TUE images was performed in consensus by a board-certified radiologist and a second year diagnostic imaging resident by evaluating the iodine subtraction, image quality and noise of VNC images based on a 5-point Likert scale.
A total of 219 regions of interest (ROIs) where drawn in abdominal organs. 72.1% of the ROIs displayed differences of less than 15 Hounsfield Units (HU) between TUE and VNC images. The differences in attenuation values of TUE and VNC were statistically significant ( < 0.05) for 5 HU in the spleen, for 10 HU and 15 HU additionally in the liver, musculature and renal cortices. These findings support the equivalence between VNC and TUE images. An average score of 4.4 was achieved for iodine subtraction across all patients, which encompasses all organ values, with no individual patient scoring below 4.0.
VNC images present a promising alternative to TUE images for abdominal organs without pathology in rabbits with the benefit of eliminating motion between the compared series and reducing examination time and radiation exposure by replacing pre-contrast scans. Further research is necessary to demonstrate the applicability of the technique to morphologically diseased organs.
光谱探测器计算机断层扫描（SDCT）能够生成从增强扫描中获得的虚拟平扫（VNC）图像，此前已在健康犬类中进行过研究。这项技术对于清醒状态下扫描的兔子尤其有前景，因为在平扫和增强扫描之间的运动使得比较具有挑战性。本研究旨在通过评估20只兔子的VNC图像与真实平扫（TUE）图像相比的定性和定量参数，来确定VNC图像评估腹部器官的可靠性。我们的假设是VNC系列将与TUE系列具有可比性，并且VNC图像的质量将等于甚至优于原始图像。
使用双侧单侧t检验（TOST）评估VNC和TUE系列的衰减值，并计算不同系列中每个感兴趣区域（ROI）的信噪比。此外，由一名获得委员会认证的放射科医生和一名二年级诊断成像住院医生共同对VNC图像相对于TUE图像进行定性评估，通过基于5点李克特量表评估VNC图像中的碘减影、图像质量和噪声。
共在腹部器官中绘制了219个感兴趣区域（ROI）。72.1%的ROI在TUE和VNC图像之间显示出小于15亨氏单位（HU）的差异。脾脏中5 HU、肝脏、肌肉组织和肾皮质中另外10 HU和15 HU的TUE和VNC衰减值差异具有统计学意义（<0.05）。这些发现支持了VNC和TUE图像之间的等效性。所有患者的碘减影平均得分为4.4，涵盖所有器官值，没有个体患者得分低于4.0。
对于没有病变的兔子腹部器官，VNC图像是TUE图像的一个有前景的替代方案，其好处是消除了比较系列之间的运动，并通过取代平扫减少了检查时间和辐射暴露。需要进一步研究来证明该技术对形态学病变器官的适用性。
