Nichols Kenneth J, Kesner Adam, Bhargava Kuldeep K, Bennett Paige, Palestro Christopher J
Department of Radiology, New Hyde Park Northwell, NY, USA.
Department of Medical Physics, Memorial Sloan Kettering Cancer Center New York, NY, USA.
Am J Nucl Med Mol Imaging. 2025 Aug 15;15(4):140-145. doi: 10.62347/XDLP4069. eCollection 2025.
Glomerular filtration rates (GFR's) are used to guide patient management. GFR's are based on radioactivity measurements of blood samples sampled at different times. We compared GFR computations from blood collected at 6 times to those collected at 2 timepoints. Thirty-seven GFR studies were performed on 25 patients. After intravenous administration of I-125 sodium iothalamate, 6 plasma samples were obtained at 5 min, 10 min, 15 min, 3 hr, 3.5 hr and 4 hr after injection, then counted in a well counter. Two different GFR calculation tools were applied to each set of 6 plasma counts (Methods 1 and 2), and a 2-sample algorithm (Method 3) computed GFR using only 3 hr and 4 hr data. Linear correlation between Method 1 and 2 GFR's was stronger than for Method 3 versus Methods 1 and 2 (r = 1.00 versus r = .91, P < .0001). Bland-Altman limits of agreement were larger (P < .0001) for Method 3 versus Methods 1 and 2 (-39.5 to +22.0 ml/min/1.73 m) than for Method 1 versus 2 (-7.6 to +4.5 ml/min/1.73 m). Method 3 overestimated lower GFR's and underestimated higher GFR's. Methods 1 and 2 agreed exactly in identifying 3 cases of GFR < 74 ml/min/1.73 m (κ = 1.00), while Method 3 detected only 1 of the three (κ = .48). To avoid underdiagnosing low GFR's, larger GFR sample sizes are preferable to smaller sample sizes.
肾小球滤过率（GFR）用于指导患者管理。GFR基于在不同时间采集的血样的放射性测量。我们比较了在6个时间点采集的血液与在2个时间点采集的血液所计算出的GFR。对25名患者进行了37项GFR研究。静脉注射碘他拉酸钠I - 125后，在注射后5分钟、10分钟、15分钟、3小时、3.5小时和4小时采集6份血浆样本，然后在井型计数器中计数。将两种不同的GFR计算工具应用于每组6个血浆计数（方法1和方法2），一种双样本算法（方法3）仅使用3小时和4小时的数据计算GFR。方法1和方法2计算的GFR之间的线性相关性强于方法3与方法1和方法2之间的相关性（r = 1.00对r = 0.91，P < 0.0001）。与方法1和方法2相比，方法3的布兰德 - 奥特曼一致性界限更大（P < 0.0001）（-39.5至+22.0 ml/min/1.73 m²），而方法1与方法2之间为（-7.6至+4.5 ml/min/1.73 m²）。方法3高估了较低的GFR，低估了较高的GFR。方法1和方法2在识别3例GFR < 74 ml/min/1.73 m²的病例中完全一致（κ = 1.00），而方法3在这三例中仅检测到1例（κ = 0.48）。为避免漏诊低GFR，较大的GFR样本量比较小的样本量更可取。
