1 Department of Radiology, New York University Langone Medical Center, 660 1st Ave, New York, NY 10016.
AJR Am J Roentgenol. 2014 Apr;202(4):778-83. doi: 10.2214/AJR.13.11321.
The purpose of this study was to evaluate split renal function, estimate single-kidney renal function, and identify cause of obstruction in patients with ureteropelvic junction (UPJ) obstruction by using contrast-enhanced dynamic MR renography (MRR).
Seventeen patients with UPJ obstruction underwent MRR and diuresis nuclear renography. Nuclear renography assessment of split renal function and mechanical versus functional obstruction served as the reference standard. The Baumann-Rudin model for determining glomerular filtration rate (GFR) was applied to generate single-kidney renal function (SK-GFRMRR) from MRR cortical and medullary enhancement curves. MRR split renal function of the right kidney (SK-GFRMRR of the right kidney normalized to the sum of SK-GFRMRR of both kidneys) was compared with nuclear renography. The MRR estimate of total GFR (eGFRMRR) was compared with that derived from Modification of Diet in Renal Disease (MDRD) formula (eGFRMDRD). Renal pelvic rate of signal intensity change (PUR) was compared between functionally and mechanically obstructed kidneys.
There was excellent correlation between MRR and nuclear renography measure of split renal function ratio (r = 0.87, p < 0.01), with mean difference of less than 10%. There was moderate correlation (r = 0.60, p = 0.01) between eGFRMRR and eGFRMDRD. eGFRMRR underestimated eGFRMDRD, with mean difference of 13.3 mL/min/1.73 m(2). PUR in mechanically obstructed units was significantly lower (0.39 ± 0.26 vs 2.0 ± 1.38 min(-1); p < 0.01) compared with functionally obstructed units. PUR discriminated mechanical from functional obstruction with accuracy of 89%.
In patients with UPJ obstruction, MRR can measure split renal function, estimate eGFRMDRD with moderate correlation, and accurately discriminate mechanical from functional obstruction, thus potentially providing a "one-stop shop" examination.
本研究旨在通过对比增强动态磁共振肾成像（MRR）评估肾盂输尿管连接部（UPJ）梗阻患者的分肾功能、估算单肾功能，并确定梗阻原因。
17 例 UPJ 梗阻患者行 MRR 和利尿核肾动态显像检查。核肾动态显像评估分肾功能、机械性与功能性梗阻作为参考标准。采用 Baumann-Rudin 模型从 MRR 皮质和髓质增强曲线计算单肾功能（SK-GFRMRR）。将右肾 MRR 分肾功能（右肾 SK-GFRMRR 与双肾 SK-GFRMRR 之和的比值）与核肾动态显像比较。将 MRR 估算的总肾小球滤过率（eGFRMRR）与改良肾脏病饮食研究（MDRD）公式（eGFRMDRD）得出的结果进行比较。比较功能性和机械性梗阻肾的肾盂信号强度变化率（PUR）。
MRR 与核肾动态显像分肾功能比值的相关性极好（r = 0.87，p < 0.01），平均差值小于 10%。eGFRMRR 与 eGFRMDRD 中度相关（r = 0.60，p = 0.01）。eGFRMRR 低估了 eGFRMDRD，平均差值为 13.3 mL/min/1.73 m2。机械性梗阻单位的 PUR 明显低于功能性梗阻单位（0.39 ± 0.26 比 2.0 ± 1.38 min-1；p < 0.01）。PUR 以 89%的准确率区分机械性和功能性梗阻。
在 UPJ 梗阻患者中，MRR 可测量分肾功能，与 eGFRMDRD 具有中度相关性，并且能准确区分机械性和功能性梗阻，因此可能提供一种“一站式”检查。
