Advanced Clinical Research Center, Fukushima Medical University, Hikarigaoka 1, Fukushima, 960-1295, Japan.
Department of Radiology, Fukushima Medical University, Hikarigaoka 1, Fukushima, 960-1295, Japan.
Ann Nucl Med. 2020 May;34(5):349-357. doi: 10.1007/s12149-020-01455-w. Epub 2020 Mar 13.
Gamma camera-based measurement of glomerular filtration rate (GFR) with Tc-diethylenetriaminepentaacetic acid (DTPA) is an established non-invasive measurement of split renal function; however, it is not as accurate as the plasma sample method. Therefore, study into improving the accuracy of such method is clinically relevant. The aim of this study was to elucidate the feasibility of gamma camera-based GFR measurement using renal depth evaluated by lateral scan of Tc-DTPA renography and comparing the results with those of GFR using renal depth measured by CT, and three representative formulas.
The study population comprised 38 patients (median, 69 years; male 28, female 10; median estimated GFR, 67.4 ml/min) with renourinary disorders. Scintigraphy was performed after intravenous injection of 370 MBq Tc-DTPA by dynamic data acquisition for 20 min, followed by a bilateral static scan of the abdomen for 3 min. All patients underwent computed tomography (CT) within 2 months from renography. GFR was calculated by renography using renal depth determined in five ways; lateral scan of Tc-DTPA, CT, and three formulas previously created with using weight, height and age. GFRs were compared with estimated GFR (eGFR). The depth of both kidneys measured as described above was compared and evaluated the laterality of the renal depth.
The median values of GFR calculated with renal depth determined by Tc-DTPA renography, CT, and the three formulas were 87.3, 83.9, 67.8, 68.3, and 71.5 ml/min, respectively. All of them correlated significantly with eGFR (r = 0.734, r = 0.687, r = 0.728, r = 0.726, and r = 0.686, respectively), however, no significant difference was observed among five correlation coefficients. Bland-Altman plot revealed that eGFR had error and fixed bias when compared with GFRs calculated using renal depth determined by renography, CT, and Taylor's formula. The depth of both kidneys measured by Tc-DTPA renography was equivalent to that measured by CT, however, those measured by the three formulas were significantly smaller than that measured by Tc-DTPA renography. The depth of the right kidney was larger than that of the left kidney using all three formulas in all patients. However, CT detected only 66% of patients to have a deeper right kidney than left kidney.
Lateral scanning is a feasible procedure to measure renal depth for accurate and reasonable split GFR measurements using Tc-DTPA renography.
使用 Tc-二乙三胺五乙酸（DTPA）的伽马相机肾小球滤过率（GFR）测量是一种已建立的肾功能分侧测量的非侵入性方法；然而，它不如血浆样本方法准确。因此，研究提高这种方法的准确性在临床上是相关的。本研究的目的是阐明使用 Tc-DTPA 肾图的侧扫描评估的肾脏深度进行伽马相机 GFR 测量的可行性，并将结果与使用 CT 和三种代表性公式测量的 GFR 进行比较。
研究人群包括 38 名（中位年龄 69 岁；男性 28 名，女性 10 名；中位估算肾小球滤过率 67.4 ml/min）有肾泌尿功能障碍的患者。在静脉注射 370 MBq Tc-DTPA 后，通过动态数据采集进行 20 分钟的闪烁扫描，随后进行 3 分钟的腹部双侧静态扫描。所有患者均在肾图后 2 个月内进行计算机断层扫描（CT）。使用 Tc-DTPA 侧扫描、CT 和以前使用体重、身高和年龄创建的三种公式计算 GFR。将 GFR 与估算肾小球滤过率（eGFR）进行比较。比较上述描述的两种肾脏深度，并评估肾脏深度的侧位性。
使用 Tc-DTPA 肾图、CT 和三种公式确定的肾脏深度计算的 GFR 的中位数分别为 87.3、83.9、67.8、68.3 和 71.5 ml/min。所有这些都与 eGFR 显著相关（r=0.734、r=0.687、r=0.728、r=0.726 和 r=0.686），但五个相关系数之间没有显著差异。Bland-Altman 图显示，与使用 Tc-DTPA 肾图、CT 和 Taylor 公式确定的 GFR 相比，eGFR 存在误差和固定偏差。使用 Tc-DTPA 肾图测量的双侧肾脏深度与 CT 测量的深度相等，然而，使用三种公式测量的深度明显小于 Tc-DTPA 肾图测量的深度。使用三种公式在所有患者中，右肾的深度均大于左肾。然而，CT 仅检测到 66%的患者右肾比左肾深。
使用 Tc-DTPA 肾图进行侧扫描是一种可行的方法，可以测量肾脏深度，从而进行准确合理的 GFR 分侧测量。
