Chu W C W, Lam W W M, Chan K W, Yeung C K, Lee K H, Sihoe J D Y
Department of Diagnostic Radiology and Organ Imaging, The Chinese University of Hong Kong, Prince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, Hong Kong SAR, China.
BJU Int. 2004 Apr;93(6):830-4. doi: 10.1111/j.1464-410X.2003.04725.x.
To evaluate the use of dynamic gadolinium diethylenetriaminepenta-acetic acid (DTPA)-enhanced magnetic resonance urography (Gd-MRU) for assessing kidneys with markedly dilated pelvicalyceal systems and impaired function.
Eight children (mean age 30 months, sd 25) were assessed, diagnosed as having gross unilateral hydronephrosis with a mean (sd) anteroposterior renal pelvic diameter of 36 (7) mm and reduced (30-40%) renal function. Dynamic Gd-MRU was performed after the patients were pre-loaded with intravenous fluid and diuretics, and comprised a dynamic T1-weighted sequence after Gd-DTPA (0.1 mmol/kg body weight) was administered, with a time-intensity curve of each kidney produced. Drainage was diagnosed by a clearly declining time-intensity curve and direct visualization of contrast medium within the ureter in several frames. High-grade or complete obstruction was diagnosed when drainage of contrast medium could not be detected. Gd-MRU results were compared with diuresis radionuclide (mercapto-acetyltriglycine, MAG3) renography within the same week. Unobstructive units detected by Gd-MRU were treated conservatively with a close follow-up by ultrasonography and radionuclide studies.
Diuresis MAG3 renography showed drainage in three dilated units and poor washout in five; in contrast, Gd-MRU showed drainage in seven dilated systems (three showed poor washout by MAG3), and obstruction in the remaining case. The unobstructed units detected by MRU under conservative treatment thus showed no further deterioration of renal function or progressive hydronephrosis in the subsequent follow-up (mean 18 months, range 15-23).
These preliminary results suggest that dynamic Gd-MRU is a useful noninvasive imaging method in distinguishing obstructive from unobstructive dilated systems, particularly in patients with hydronephrosis and reduced renal function.
评估动态钆喷酸葡胺（DTPA）增强磁共振尿路造影（Gd-MRU）在评估肾盂肾盏系统明显扩张且功能受损的肾脏方面的应用。
对8名儿童（平均年龄30个月，标准差25）进行评估，这些儿童被诊断为单侧严重肾积水，平均（标准差）肾盂前后径为36（7）mm，肾功能降低（30 - 40%）。在患者静脉输注液体和利尿剂后进行动态Gd-MRU检查，检查包括静脉注射钆喷酸葡胺（0.1 mmol/kg体重）后进行动态T1加权序列扫描，并生成每个肾脏的时间 - 强度曲线。通过时间 - 强度曲线明显下降以及在多个图像帧中直接观察到输尿管内的造影剂来诊断引流情况。当未检测到造影剂引流时诊断为重度或完全梗阻。将Gd-MRU结果与同一周内的利尿放射性核素（巯基乙酰三甘氨酸，MAG3）肾图结果进行比较。Gd-MRU检测到的无梗阻单位采用保守治疗，并通过超声和放射性核素检查密切随访。
利尿MAG3肾图显示3个扩张单位有引流，5个有排泄延迟；相比之下，Gd-MRU显示7个扩张系统有引流（3个经MAG3检查显示排泄延迟），其余1例为梗阻。因此，MRU检测到的无梗阻单位在保守治疗后，在随后的随访中（平均18个月，范围15 - 23个月）肾功能未进一步恶化，肾积水也未进展。
这些初步结果表明，动态Gd-MRU是一种有用的非侵入性成像方法，可用于区分梗阻性和非梗阻性扩张系统，特别是在肾积水且肾功能降低的患者中。
