Oliveira Cintia R, Ranallo Frank N, Pijanowski Gerald J, Mitchell Mark A, O'Brien Mauria A, McMichael Maureen, Hartman Susan K, Matheson Jodi S, O'Brien Robert T
Department of Veterinary Clinical Medicine, University of Illinois at Urbana-Champaign, 1008 W. Hazelwood Dr, Urbana, IL 61802, USA.
Vet Radiol Ultrasound. 2011 Jan-Feb;52(1):41-52.
The VetMousetrap, a novel device that allows computed tomography (CT) of awake cats and provides a clinically supportive environment, is described. Ten normal cats were used to test the device for ambient internal oxygen, carbon dioxide levels, and temperature. Twenty-two awake normal cats were imaged using a 16-multislice helical CT unit to evaluate dose-equivalent protocols. Two different X-ray tube potentials (kV), 80 and 120, and two different helical pitches, 0.562 and 1.75, were evaluated. The signal intensity of the pulmonary parenchyma (SIlung), signal intensity of background (SIbackgr), contrast, noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were calculated. Three evaluators ranked the images for sharpness of liver margins, motion, helical, and windmill artifacts. CT was successfully completed in 20 of 22 cats. No artifacts directly related to the device were detected. Overall, 75 of 80 (94%) examinations were judged to have absent or minimal motion artifact. A statistically significant difference was found for SNR (P = 0.001) and CNR (P = 0.001) between all protocols. The higher pitch protocols had significantly lower noise and higher SNR and CNR, lower motion artifact but greater helical artifacts. A protocol using 80 kV, 130 mA, 0.5s, and 0.562 pitch with 1.25mm slice thickness, and 0.625 mm slice reconstruction interval is recommended. The VetMousetrap appears to provide the opportunity for diagnostic CT imaging of the thorax of awake cats.
本文介绍了一种新型设备——兽医捕鼠器，它能够对清醒的猫进行计算机断层扫描（CT），并提供临床支持环境。使用10只正常猫来测试该设备的环境内部氧气、二氧化碳水平和温度。使用16排螺旋CT设备对22只清醒的正常猫进行成像，以评估等效剂量方案。评估了两种不同的X射线管电压（kV），即80和120，以及两种不同的螺距，即0.562和1.75。计算了肺实质的信号强度（SIlung）、背景信号强度（SIbackgr）、对比度、噪声、信噪比（SNR）和对比噪声比（CNR）。三名评估人员对肝脏边缘清晰度、运动、螺旋和风车伪影的图像进行了排名。22只猫中有20只成功完成了CT扫描。未检测到与该设备直接相关的伪影。总体而言，80次检查中有75次（94%）被判定无运动伪影或运动伪影极小。所有方案之间的SNR（P = 0.001）和CNR（P = 0.001）存在统计学显著差异。较高螺距的方案具有显著更低的噪声、更高的SNR和CNR、更低的运动伪影但更大的螺旋伪影。推荐使用80 kV、130 mA、0.5s、0.562螺距、1.25mm层厚和0.625mm层重建间隔的方案。兽医捕鼠器似乎为清醒猫的胸部诊断性CT成像提供了机会。
