Lin E, Alavi A
Division of Nuclear Medicine, Hospital of the University of Pennsylvania, Philadelphia 19104, USA.
Clin Nucl Med. 1998 Apr;23(4):217-22. doi: 10.1097/00003072-199804000-00005.
Renal transplant perfusion curves obtained using Tc-99m MAG3 differ from those with Tc-99m DTPA. The perfusion curve can be divided into a first phase (up to the first-pass peak) and a second phase (the curve after the initial peak). The second phase of the MAG3 perfusion curve is usually ascending in contrast to the descending Tc-99m DTPA curve. This ascending MAG3 curve reflects early tubular extraction of MAG3. However, the second phase of the MAG3 curve is sometimes flat or descending. We hypothesized that a flat or descending curve reflects poor early tubular extraction and therefore graft dysfunction. Ninety-two studies of 59' renal transplant patients were retrospectively reviewed. The second phase of the perfusion curve was visually classified as ascending, flat, or descending. 77.2% of studies had ascending curves, 16.3% flat curves, and 6.5% descending curves. A descending curve had a positive predictive value (PPV) of 100% for medical graft dysfunction, while a flat curve had a PPV of 93.3%. A nonascending second phase curve was specific (96.4%) but not sensitive (33.9%) for graft dysfunction. Patients with acute tubular necrosis were not significantly more likely to have a nonascending curve than those with acute rejection. There was no significant difference in creatinine level between patients with medical graft dysfunction and ascending vs. nonascending curves. A nonascending second phase Tc-99m MAG3 perfusion curve is predictive for graft dysfunction. An ascending curve is nonspecific and can be seen in both normally and poorly functioning grafts.
使用锝-99m巯基乙酰三甘氨酸（Tc-99m MAG3）获得的肾移植灌注曲线与使用锝-99m二乙三胺五乙酸（Tc-99m DTPA）的曲线不同。灌注曲线可分为第一阶段（直至首次通过峰值）和第二阶段（初始峰值后的曲线）。与下降的Tc-99m DTPA曲线相比，MAG3灌注曲线的第二阶段通常是上升的。这种上升的MAG3曲线反映了MAG3早期的肾小管摄取。然而，MAG3曲线的第二阶段有时是平坦的或下降的。我们假设平坦或下降的曲线反映了早期肾小管摄取不良，因此提示移植肾功能障碍。对59例肾移植患者的92项研究进行了回顾性分析。灌注曲线的第二阶段通过视觉分类为上升、平坦或下降。77.2%的研究曲线上升，16.3%平坦，6.5%下降。下降曲线对移植肾功能障碍的阳性预测值（PPV）为100%，而平坦曲线的PPV为93.3%。非上升的第二阶段曲线对移植肾功能障碍具有特异性（96.4%）但不敏感（33.9%）。急性肾小管坏死患者出现非上升曲线的可能性并不比急性排斥患者显著更高。移植肾功能障碍患者中，肌酐水平在曲线上升与非上升的患者之间没有显著差异。非上升的第二阶段Tc-99m MAG3灌注曲线可预测移植肾功能障碍。上升曲线是非特异性的，在移植肾功能正常和不良的情况下均可出现。
