Caride V J, Zubal I G
Department of Radiology, Hospital of Saint Raphael, Yale Medical School, New Haven, Connecticut 06511, USA.
J Nucl Med. 1995 Sep;36(9):1602-4.
To further validate the rate of renal uptake of the 99mTc-DTPA-plasma volume product (RUPV) method to estimate glomerular filtration rate (GFR), 104 determinations were performed and compared to blood sample of GFR assays. The interassay consistency was also studied in 42 patients.
The studies were performed with 370-550 MBq (10-15 mCi) of 99mTc-DTPA and a gamma camera. The 3-min cumulative renal uptake was calculated from the renogram curves and expressed as the rate of renal uptake in min-1. The plasma volume, in milliliters, was estimated from the patient's body weight. The GFR (ml/min) was calculated from [RU] x [PV] and by using two blood samples. To study interassay consistency, two determinations of GFR were performed on separate days.
The regression equation relating the rate of renal uptake (RU) in the abscissa and the GFR obtained from plasma samples in the ordinate is: y = 3.13 + 10.5x (n = 104; r = 0.90). The regression equation of RUPV estimated GFR (x) compared to the GFR calculated from blood samples (y) is: y = 6.9 + 0.91x (n = 104; r = 0.94). The interassay consistency study showed no statistically significant difference between measurements obtained on Days 1 and 2. The mean +/- s.e.m. GFR for each determination were 84.3 +/- 6.12 and 81.9 +/- 6.21. For the blood sample method, the mean s.e.m. for each day were 87.26 +/- 6.69 and 96.86 +/- 6.58 (p < 0.05). The percent variation coefficient for the RUPV method was: CV% = 6.8 +/- 2.7 and 12.1 +/- 3.3 (p < 0.03) for the blood sample method.
The observed accuracy of the determination is comparable to that in our previous study of a separate patient population at another hospital. This method would be suitable for interinstitutional comparison and for longitudinal patient studies.
为进一步验证99mTc-DTPA血浆容积产物（RUPV）法估算肾小球滤过率（GFR）的肾脏摄取率，进行了104次测定，并与GFR检测的血样进行比较。还对42例患者进行了批间一致性研究。
研究使用370 - 550 MBq（10 - 15 mCi）的99mTc-DTPA和一台γ相机。从肾图曲线计算3分钟的累积肾脏摄取量，并表示为每分钟的肾脏摄取率。根据患者体重估算血浆容积（毫升）。GFR（毫升/分钟）通过[RU]×[PV]并使用两份血样计算得出。为研究批间一致性，在不同日期进行两次GFR测定。
横坐标为肾脏摄取率（RU），纵坐标为从血浆样本获得的GFR的回归方程为：y = 3.13 + 10.5x（n = 104；r = 0.90）。RUPV估算的GFR（x）与血样计算的GFR（y）的回归方程为：y = 6.9 + 0.91x（n = 104；r = 0.94）。批间一致性研究表明，第1天和第2天的测量结果无统计学显著差异。每次测定的平均±标准误GFR分别为84.3±6.12和81.9±6.21。血样法每天的平均标准误分别为87.26±6.69和96.86±6.58（p < 0.05）。RUPV法的变异系数百分比为：CV% = 6.8±2.7，血样法为12.1±3.3（p < 0.03）。
观察到的测定准确性与我们之前在另一家医院对另一组患者的研究相当。该方法适用于机构间比较和患者纵向研究。
