3.0T MR体素内不相干运动成像、弥散张量成像及T1 mapping检测健康成年人肾功能

目的 观察3.0T MR体素内不相干运动成像(IVIM)、弥散张量成像(DTI)及T1 mapping技术检测健康成年人肾功能的价值。方法 对前瞻性招募的22名健康成年志愿者行3.0T MR肾脏IVIM、DTI及T1 mapping扫描,获得左、右肾皮髓质MRI参数,包括IVIM相关参数纯水分子扩散系数(D)、灌注相关扩散系数(D^*)和灌注分数(f)、DTI相关参数各向异性分数(FA)及T1 mapping相关参数T1值;观察肾脏不同部位各参数差异,评估其与估算肾小球滤过率(eGFR)的相关性,分析其反映肾功能的价值。结果 左、右肾皮髓质上、中、下份MRI参数及左、右肾MRI参数差异均无统计学意义(P均＞0.05)。双肾皮质表观弥散系数(ADC)及D均大于髓质,而FA及T1值均小于髓质(P均<0.05);双肾髓质T1值与eGFR中度相关(r=0.718,P=0.013)。观察者间双肾皮质及髓质ADC、D、FA及T1值测值的一致性良好(ICC=0.751~0.896,P均＜0.001),双肾皮质及髓质D^*、f的一致性一般(ICC=0.489~0.668,P均＜0.001)。结论 3.0T MR IVIM、DTI及T1 mapping技术有助于检测健康成年人肾功能。

3.0T MR intravoxel incoherent motion imaging, diffusion tensor imaging and T1 mapping for evaluating renal function in healthy adults

Objective To observe the value of intravoxel incoherent motion imaging (IVIM), diffusion tensor imaging (DTI) and T1 mapping with 3.0T MR scanner for evaluating renal function in healthy adult. Methods Renal IVIM, DTI and T1 mapping of 22 prospectively recruited healthy adult volunteers were obtained with 3.0T MR scanner. MRI parameters of left and right renal cortex and medulla were measured, including IVIM related parameters of pure water molecular diffusion coefficient (D), perfusion related diffusion coefficient (D^*) and perfusion fraction (f), DTI related parameter anisotropy fraction (FA) and T1 mapping related parameter T1 value, those of different parts of kidney were compared. The correlation of MRI parameters and estimated glomerular filtration rate (eGFR) were evaluated, and the value of the above parameters for reflecting renal function were analyzed. Results There was no significant difference of MRI parameters among the upper, middle and lower parts of left and right renal cortex or medulla (all P>0.05), nor MRI parameters between left and right kidney (all P>0.05). Apparent diffusion coefficient (ADC) and D of bilateral renal cortex were higher than those of medulla (both P<0.05), while FA and T1 value of bilateral renal cortex were lower than those of medulla (both P<0.05). T1 value of bilateral renal medulla were moderately correlated with eGFR (r=0.718, P=0.013). The intra-observer consistency of ADC, D, FA and T1 values of bilateral renal cortex and medulla were all good (ICC=0.751-0.896, all P<0.001), of D^* and f of bilateral renal cortex and medulla were general (ICC=0.489-0.668, all P<0.001). Conclusion 3.0T MR IVIM, DTI and T1 mapping were helpful for evaluating renal function in healthy adults.