Gd-DTPA增强动态核磁共振和动态核素肾扫描评估幼猪正常和梗阻肾脏

Comparison of Gd-DTPA enhanced dynamic MRI and scintigraphy in evaluation of normal and obstructed kidney in swine

目的 Gd-DTPA增强动态核磁共振(MRI)和动态肾扫描评估猪正常和梗阻肾脏形态和功能的意义。方法 用Gd-DTPA(0.1mmol/kg BW)增强动态MRI评估4～7月大小幼猪(n=10)肾脏,其中正常对照组7例,单侧输尿管梗阻3例。分别对0.1～60min记录的肾脏影像进行分析并计算出肾皮质、髓质和肾盂的相对信号强度。MRI后用动态核素扫描对肾脏进行评估并对肾脏进行解剖学检查。结果 使用Gd-DTPA后,对照组肾皮质、髓质和肾盂信号强度迅速增强,1min后开始下降,肾盂最明显可降至正常的44％,以后逐渐恢复。输尿管不全梗阻肾脏的变化明显较对照组慢。扫描肾图得到的肾功能信息和MRI一致,但后者能提供更清楚的形态变化。结论 Gd-DTPA增强动态MRI除了提供更清楚的正常和梗阻肾脏形态变化外,还能提供详细功能变化信息。Gd-DTPA增强动态MRI能帮助鉴别输尿管不全梗阻。

Objective To compare Gd-DTPA enhanced dynamic MRI with scintigraphy in evalua- tion of the normal and obstructed kidney in experimental pigs. Methods The renal morphology and func- tion of experimental pigs (age 4～7 months) were evaluated by Gd-DTPA enhanced dynamic MRI (0.1 mmol/kg). Of which, 3 pigs with unilateral ureteral obstructed kidney were created by embedding the left ureter into the psoas muscle and 7 pigs served as normal controls. All kidneys were examined microscopi-cally after scintigraphy. Results Dynamic patterns of RSI differed significantly between normal and obstructed kidneys. A rapid increase in RSI in the cortex, medulla and pelvis was observed and reduced to a minimum of 44 % to the normal after one minute. In the partially obstructed kidney, the increasing of amplitude and time in mean RSI of cortex and medulla was lower and prolonged as compared to the con- trols. Dynamic MRI provided the same functional messages of kidneys as scintigraphy, but the renal mor- phological changes in MRI were clearer. Conclusions Compared to scintigraphy, Gd-DTPA enhanced dy- namic MRI provides more clear information of morphological and renal concentrated function of obstructed kidney. It is helpful to the differential diagnosis of partial ureteral obstruction.