三期CT扫描测量肾脏灌注和滤过功能的新技术开发及验证

X-ray computed tomography (CT) can provide detailed morphological information, so be the routine examination before renal surgery. Isotope renogram is also needed preoperatively to check renal perfusion and filtration (glomerular filtration rate, GFR). Therefore, it will be of great clinical interest to achieve the assessment of the renal morphology, perfusion and filtration with a one-stop technique. According to the biphasic CT perfusion (BiCTp) technique recently reported by us in Radiology, the renal blood flow (RBF) can be calculated from precontrast and arterial phase images. Based on the BiCTp, we add in the excretory phase acquisition and build a new algorithm of the CT measurement of glomerular filtration rate (CT-GFR), to develop a one-stop technique for measurement of perfusion and filtration. The one-stop CT examination will be performed in 30 cases of unilateral Hydronephrosis swine model. Isotope renogram plus dual plasma sampling method will be employed as the reference standard for determination of the accuracy and the systemic deviation of the CT-GFR, which will be performed by using correlation analysis and Bland-Altman plot analysis. Paired t test of the RBF and CT-GFR will be performed between the normal and hydronephrosis. Three hundred patients with unilateral renal lesions will be included and undergo the one-stop CT examination. With the Isotope renogram as the reference standard, the impact on the accuracy of the CT-GFR will be assessed regarding the lesion type and degree of renal function damage. Based on the results of the current study a post-processing software will be developed for further clinical promotion.

CT能提供精细的形态信息，是肾脏的术前常规检查，但术前还需行同位素肾图来检测灌注和肾小球滤过率（GFR)，因此一站式评估肾脏形态、灌注和滤过的技术有重要的临床价值。我们近期在Radiology上报道了CT双期扫描灌注技术，通过平扫和动脉期图像计算肾血流量（renal blood flow, RBF），本研究在此基础上增加排泄期扫描并假设GFR的新算法CT-GFR来实现灌注和滤过的一站式检查。建立单侧肾积水实验猪模型30头，行CT扫描，以同位素肾图和双血浆法为参考标准,用相关分析和Bland-Altman 法评估CT-GFR的准确性和系统偏差，用配对t检验比较正常肾和积水肾的RBF及CT-GFR；纳入单侧肾脏病变患者300例行CT扫描，以同位素肾图为参考标准，评估不同病变类型和肾功能损害程度对CT-GFR准确性的影响。依据研究结果制作配套后处理软件实现肾脏灌注和滤过的自动计算，供临床推广用。

CT能提供精细的形态信息，是肾脏的术前常规检查，但术前还需行同位素肾图来检测灌注和肾小球滤过率（GFR)，因此一站式评估肾脏形态、灌注和滤过的技术有重要的临床价值。本项研究通过建立新的CT-GFR算法来实现CT灌注和滤过的一站式检查，并以同位素肾图和双血浆法为参考标准,用相关分析和Bland-Altman 法评估和验证CT-GFR的准确性和可能存在的系统偏差，研究结果显示：单肾CT-GFR（45.02±13.91）和单肾Gates-GFR（51.21±14.76）之间的配对差异为6.19±5.63 ml / min，p <0.001，显示12.1％的系统性低估，测量偏差为±11.03 ml /min ±21.5％，CT-GFR和Gates-GFR之间有良好的相关性（r = 0.87，p <0.001）。通过本研究我们证实了CT-GFR新技术的准确性和临床实用性，后续会进一步配套完成后处理软件来实现肾脏灌注和滤过的自动计算，供临床推广用。