MR扩散成像初步观察慢性肾病患者肾脏

Preliminary observation of chronic kidney disease with MR diffusion-weighted imaging

目的探讨扩散加权成像对于评价慢性肾病肾功能的意义。方法选择慢性肾病患者26例以及正常对照22例(除外肾脏病变),采用呼吸门控技术,行扩散加权成像,使用SE-EPI序列,选择扩散敏感因子b值分别为0、50、100、300、500、700s/mm2,计算并比较两组肾实质ADC值,并将ADC值分别与血清肌酐和尿素氮水平进行相关性分析。结果随着b值的升高,肾实质ADC值呈现降低的趋势。当b值为50、100、300s/mm2时病例组ADC值与对照组没有明显差异;b值为500、700s/mm2时对应病例组ADC值较对照组降低(P<0.05)。b值为500、700s/mm2时对应ADC值与sCr存在一定的负性相关关系(r值分别为-0.423和-0.494,P<0.05);b值为700s/mm2时对应ADC值与BUN存在一定的负性相关关系(r=-0.466,P<0.05)。结论扩散加权成像能够反映慢性肾病肾功能的状态,高b值对应ADC与sCr和BUN呈一定的负相关关系,对于无创性评价肾脏功能具有重要的价值。

Objective To evaluate renal function of chronic kidney failure with diffusion-weighted imaging （DWI）. Methods Twenty-six patients with chronic kidney failure and 22 healthy subjects underwent diffusion-weighted echoplanar MR imaging （EPI） by breath-gating with six different strengths of motion probing gradients （b = 0, 50, 100, 300, 500, 700 s/mm^2）. Apparent diffusion coefficient （ADC） was calculated from different b-value and compared. Correlation between ADC and sCr/BUN level was evaluated. Results ADC value tended to decrease with increase of b value. At lower b values （b=50, 100, 300 s/mm^2）, no statistical difference of ADC values was found between patients and controls, while ADC val- ues of patients declined obviously than healthy subjects at higher b values （b=500, 700 s/mm^2 , P〈0. 05）. ADC values （b=500, 700 s/mm^2） were negatively relative to the sCr level （r=-0. 423, r=-0. 494, respectively, P〈0.05）, and were negatively relative to the BUN level （b= 700 s/mm^2, r=-0. 466, P〈0. 05）. Conclusion Diffusion-weighted MR imaging is a potential method in noninvasively evaluating renal dysfunction of chronic kidney failure.