Hannover Medical School-Germany, Institute for Diagnostic and Interventional Radiology, Carl-Neuberg-Str. 1, 30625 Hannover, Germany.
Eur Radiol. 2011 Nov;21(11):2427-33. doi: 10.1007/s00330-011-2189-0. Epub 2011 Jun 28.
To evaluate MR diffusion tensor imaging (DTI) as non-invasive diagnostic tool for detection of acute and chronic allograft dysfunction and changes of organ microstructure.
15 kidney transplanted patients with allograft dysfunction and 14 healthy volunteers were examined using a fat-saturated echo-planar DTI-sequence at 1.5 T (6 diffusion directions, b = 0, 600 s/mm²). Mean apparent diffusion coefficient (ADC) and mean fractional anisotropy (FA) were calculated separately for the cortex and for the medulla and compared between healthy and transplanted kidneys. Furthermore, the correlation between diffusion parameters and estimated GFR was determined.
The ADC in the cortex and in the medulla were lower in transplanted than in healthy kidneys (p < 0.01). Differences were more distinct for FA, especially in the renal medulla, with a significant reduction in allografts (p < 0.001). Furthermore, in transplanted patients a correlation between mean FA in the medulla and estimated GFR was observed (r = 0.72, p < 0.01). Tractography visualized changes in renal microstructure in patients with impaired allograft function.
Changes in allograft function and microstructure can be detected and quantified using DTI. However, to prove the value of DTI for standard clinical application especially correlation of imaging findings and biopsy results is necessary.
评估磁共振扩散张量成像（DTI）作为一种非侵入性诊断工具，用于检测急性和慢性移植物功能障碍以及器官微观结构的变化。
对 15 例移植物功能障碍的肾移植患者和 14 例健康志愿者进行 1.5 T 磁共振检查（6 个扩散方向，b=0，600 s/mm²）。分别计算皮质和髓质的平均表观扩散系数（ADC）和平均各向异性分数（FA），并比较健康和移植肾脏之间的差异。此外，还确定了扩散参数与估算肾小球滤过率（eGFR）之间的相关性。
与健康肾脏相比，移植肾脏的皮质和髓质 ADC 均较低（p<0.01）。FA 的差异更为明显，尤其是在移植肾脏的髓质，差异非常显著（p<0.001）。此外，在移植患者中，还观察到髓质平均 FA 与 eGFR 之间存在相关性（r=0.72，p<0.01）。DTI 可可视化显示移植物功能障碍患者的肾脏微观结构变化。
DTI 可用于检测和量化移植物功能和微观结构的变化。然而，为了证明 DTI 在标准临床应用中的价值，特别是成像结果与活检结果的相关性，还需要进一步研究。
