论文部分内容阅读
目的:探讨体素内不相干运动(IVIM)相关参数值在正常儿童肾脏皮髓质之间的差异,为儿童肾脏病变在磁共振(MR)IVIM-DWI成像时提供正常参考值。方法:28例健康志愿者均行中腹部常规MRI平扫和IVIM-DWI检查,b值取0、50、100、150、200、400、600 s·mm~(-2)。将扫描原始图像导入IVIM后处理软件,对左、右侧肾皮质及髓质分别划取3个像素大小为10~15的ROI,测量皮髓质血流量(BF)、体素内真性水分子扩散(D)、体素内微循环灌注(D*)、灌注分数(f)值,取3次的平均值。采用独立样本t检验评价IVIM各参数在皮髓质之间的差异;采用ROC曲线分析BF、D、D*、f值区分差异的效能。结果:28例正常儿童肾脏中:皮髓质BF值分别为(3.47±0.35)×10~(-3)、(3.28±0.23)×10~(-3)mm~2·s-1;D值分别为(2.70±0.13)×10~(-3)、(2.12±0.31)×10~(-3)mm~2·s-1,D*值分别为(15.06±1.10)×10~(-3)、(14.23±0.73)×10~(-3)mm~2·s~(-1);f值分别为(26.13±4.07)%和(32.11±3.50)%。肾脏皮质D、D*值明显高于髓质,而肾脏皮质的f值则低于髓质,差异均具有统计学意义(P=0.000、0.027、0.001)。肾脏皮、髓质BF值差异无统计学意义(P=0.109)。ROC分析得到BF、D、D*、f值曲线下面积分别为0.622、0.954、0.760、0.872(P=0.270、0.000、0.019、0.001)。结论:IVIM相关参数D、D*、f值在肾脏皮髓质中存在显著差异,其中D值区分差异的能力最强;而BF值在肾脏皮髓质之间的差异无统计学意义。
OBJECTIVE: To investigate the correlation between IVIM related parameters in renal cortex and medulla of normal children and to provide a normal reference value for magnetic resonance (MR) IVIM-DWI imaging in children with renal disease. Methods: Twenty-eight healthy volunteers underwent plain MRI and IVIM-DWI in mid-abdomen. The b values were 0, 50, 100, 150, 200, 400 and 600 s · mm ~ (-2). The scanned original images were imported into IVIM postprocessing software and three ROIs of 10-15 were plotted on the left and right renal cortex and medulla respectively. The cortical blood flow (BF), real water molecules Diffusion (D), voxel microcirculation perfusion (D *), perfusion score (f) value, take the average of 3 times. The independent sample t-test was used to evaluate the difference of IVIM parameters between the cortex and the medulla; the ROC curve was used to analyze the effectiveness of discriminating the difference between BF, D, D * and f. Results: In the normal kidneys of 28 children, BF value of cortex medulla was (3.47 ± 0.35) × 10 -3 and (3.28 ± 0.23) × 10 -3 mm 2 s -1, respectively (2.70 ± 0.13) × 10 -3 and (2.12 ± 0.31) × 10 -3 mm 2 s -1 respectively, and the values of D * were (15.06 ± 1.10) × 10 ~ -3 and 14.23 ± 0.73 × 10 -3 mm 2 s -1, respectively. The f values were (26.13 ± 4.07)% and (32.11 ± 3.50)% respectively. The D, D * values of renal cortex were significantly higher than those of the medulla, but the values of renal cortex were lower than that of the medulla. The differences were statistically significant (P = 0.000,0.027,0.001). There was no significant difference in BF between kidney and medulla (P = 0.109). The areas under the curves of BF, D, D * and f obtained by ROC analysis were 0.622,0.954,0.760,0.872 (P = 0.270,0.000,0.019,0.001) respectively. Conclusion: There are significant differences in D, D * and f values of IVIM in renal cortex and medulla, among which the D value is the most effective in distinguishing the differences. There is no significant difference in BF between renal cortex and medulla.