Nephrology and Dialysis Unit, Infermi Hospital, Rimini, Italy.
Am J Nephrol. 2011;33(2):176-84. doi: 10.1159/000324039. Epub 2011 Feb 10.
BACKGROUND/AIMS: Total renal volume (TRV) is an important index to evaluate the progression of autosomal-dominant polycystic kidney disease (ADPKD). TRV has been assessed by manually tracing renal contours from CT or MR scans, often employing contrast medium (CM). We developed a fast and nearly automated technique based on the analysis of MR images acquired without CM injection for TRV quantification.
30 ADPKD patients underwent MRI. After the selection of one point inside each kidney for the entire volume, the automatic extraction of kidney contours was performed on each acquired slice; the segmentation procedure was based on region growing and on the application of morphological operators and curvature-based motion. The area inside each contour was calculated and TRV was derived. Volume measurements were validated by comparison with measurements obtained by stereology.
TRV estimated in patients was 768 ± 545 ml (range 161-3,111 ml). The automatic measurements were in excellent correlation with the manual ones (r = 0.99, y = x - 0.7), with a small bias and narrow limits of agreement in both absolute (-5 ± 37 ml) and percentage (-0.6 ± 9.6%) terms.
This preliminary study showed the feasibility of a fast and nearly automated method for determining TRV; importantly it does not require the use of potentially nephrotoxic CM.
背景/目的：总肾体积（TRV）是评估常染色体显性多囊肾病（ADPKD）进展的重要指标。TRV 通过手动从 CT 或 MR 扫描中描绘肾轮廓来评估，通常使用造影剂（CM）。我们开发了一种基于无 CM 注射的 MR 图像分析的快速且几乎自动化的技术，用于 TRV 定量。
30 例 ADPKD 患者接受 MRI 检查。在为整个体积选择每个肾脏内的一个点后，在每个采集的切片上自动提取肾轮廓；分割过程基于区域生长以及形态运算符和基于曲率的运动的应用。计算每个轮廓内的面积，并得出 TRV。通过与体视学法获得的测量值进行比较来验证体积测量值。
患者的 TRV 估计值为 768 ± 545 ml（范围 161-3111 ml）。自动测量与手动测量高度相关（r = 0.99，y = x - 0.7），具有较小的偏差和较窄的一致性界限，无论是绝对值（-5 ± 37 ml）还是百分比（-0.6 ± 9.6%）。
这项初步研究表明，快速且几乎自动化的方法确定 TRV 是可行的；重要的是，它不需要使用潜在的肾毒性 CM。
