Dagli M S, Caride V J, Carpenter S, Zubal I G
Department of Diagnostic Radiology, Yale Medical School, New Haven, Connecticut 06520-8042, USA.
J Nucl Med. 1997 Aug;38(8):1285-90.
We have developed an image-based compartmental analysis for estimating effective renal plasma flow (ERPF in units of milliliters per minute) from the full time-activity curves of regions of interest (ROI) placed over the heart, kidneys and bladder.
Kidney or time-activity curves are corrected for physical attenuation using estimates of kidney depth derived from patient height and weight. Estimates of the calibration factors, Kp and Kb (mCl/counts/sec), for the plasma and bladder time-activity curves are determined by applying the following ROI analysis to each frame of the dynamic scan: (Kp)Pc(t) + (Kb)Bc(t) = Di - Rq(t), where P c(t) and Bc(t) represent the counting rates measured in ROI placed over the left ventricle blood pool and bladder at time t; Di is the known total injected dose, and Rq(t) represents the millicurie of tracer in the kidneys at time t. Once Kp and Kb have been determined by regression, the calibrated time activity curves are used to solve for the physiological parameter fERPF (min-1), which represents the fraction of the total body plasma cleared of mertiatide per min. The ERPF calculated by the product of fERPF and plasma volume, determined from patient weight, was compared to the ERPF as calculated by blood samples and the Schlegel and renal uptake plasma volume product scintigraphic techniques.
Twenty-five adult patients with a wide range of ages and renal function were studied. The results of this image-based method for calculating ERPF correlated well with the values obtained from blood samples (linear regression slope = 1.06; y-int = -34.68 ml/min, r = 0.905) and offered a significant improvement over both the Schlegel and renal uptake plasma volume product estimates (p < 0.05).
A scintigraphic estimation of ERPF without blood samples using time-activity data from the heart, kidneys and bladder acquired over the entire renogram is feasible and correlates well with more invasive techniques requiring blood samples.
我们开发了一种基于图像的分区分析方法，用于根据放置在心脏、肾脏和膀胱上的感兴趣区域（ROI）的全时活度曲线来估计有效肾血浆流量（ERPF，单位为毫升每分钟）。
利用根据患者身高和体重得出的肾脏深度估计值，对肾脏或时活度曲线进行物理衰减校正。通过对动态扫描的每一帧应用以下ROI分析，确定血浆和膀胱时活度曲线的校准因子Kp和Kb（毫居里/计数/秒）：(Kp)Pc(t) + (Kb)Bc(t) = Di - Rq(t)，其中Pc(t)和Bc(t)分别代表在时间t时放置在左心室血池和膀胱上的ROI中测得的计数率；Di是已知的总注射剂量，Rq(t)代表时间t时肾脏中示踪剂的毫居里数。一旦通过回归确定了Kp和Kb，就使用校准后的时活度曲线来求解生理参数fERPF（分钟⁻¹），它代表每分钟全身清除美替拉酮的血浆分数。将通过fERPF与根据患者体重确定的血浆体积的乘积计算得出的ERPF，与通过血样以及施莱格尔和肾摄取血浆体积乘积闪烁显像技术计算得出的ERPF进行比较。
对25名年龄和肾功能范围广泛的成年患者进行了研究。这种基于图像的计算ERPF的方法的结果与从血样中获得的值具有良好的相关性（线性回归斜率 = 1.06；截距 = -34.68毫升/分钟，r = 0.905），并且比施莱格尔和肾摄取血浆体积乘积估计值有显著改善（p < 0.05）。
使用在整个肾图过程中获取的心脏、肾脏和膀胱的时活度数据，在无需血样的情况下进行ERPF的闪烁显像估计是可行的，并且与需要血样的更具侵入性的技术具有良好的相关性。
