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目的评价在肝脏 MR 扩散加权成像(DWI)中应用改良敏感编码(mSENSE)技术是否有助于提高图像质量及对肝细胞癌(HCC)小病灶的表观扩散系数(ADC)值测量有无影响。方法分别用常规 DWI 和 mSENSE-DWI 对32例47个 HCC 小病灶行单次屏气自旋回波-平面回波(sE-EPI)DWI,扩散梯度因子(b)值为300、500、800 s/mm~2。对图像质量、对比噪声比(CNR)、病灶的ADC 值进行观测和比较,运用配对 Wilcoxon signed rank 和 Friedman 检验进行统计学分析。结果图像质量 DWI 组 b=300 s/mm~2时图像评分2级5例、3级24例、4级3例,b=500 s/mm~2时2级9例、3级22例、4级1例,b=800 s/mm~2时1级2例、2级24例、3级6例;mSENSE-DWI 组 b=300 s/mm~2时3级4例、4级25例、5级3例,b=500 s/mm~2时3级10例、4级20例、5级2例,b=800 s/mm~2时2级7例、3级23例、4级2例。同一 b 值条件下,mSENSE-DWI 组的图像质量均优于常规 DWI 组(3个不同 b 值组的 Z 分别为-5.578、-5.488、-4.796,P 值均<0.01)。DWI 组病灶的中位 ADC 值在 b=300、500、800 s/mm~2时分别为(1.578×10~(-3))、(1.390×10~(-3))、(1.173×10~(-3))mm~2/s,mSENSE-DWI 组病灶的中位 ADC 值在3个 b 值下分别为(1.381×10~(-3))、(1.242×10~(-3))、(1.136×10~(-3))mm~2/s,在大 b 值条件下(500、800 s/mm~2),2组所测得的病灶 ADC 值差异无统计学意义(Z 值分别为-0.873、-0.862,P 值分别为0.383、0.388)。结论在肝脏 DWI 中应用 mSENSE 技术可获得高质量的图像,同时对 HCC 小病灶的 ADC 值测量没有影响。
Objective To evaluate whether using modified sensitive coding (mSENSE) in liver MR diffusion-weighted imaging (DWI) is helpful in improving image quality and in measuring apparent diffusion coefficient (ADC) values in small lesions of hepatocellular carcinoma (HCC) . Methods Single-breath-hold echo-plane echo (sE-EPI) DWI was performed in 32 patients with 47 small HCC lesions using conventional DWI and mSENSE-DWI. The diffusion gradient factor (b) mm ~ 2. The image quality, contrast-to-noise ratio (CNR) and lesion ADC values were observed and compared. Statistical analysis was performed using paired Wilcoxon signed rank and Friedman test. Results Image quality DWI group b = 300 s / mm ~ 2, grade 2 in 5 cases, grade 3 in 24 cases and grade 4 in 3 cases, b = 500 s / mm ~ 2 in grade 2 in 9 cases, grade 3 in 22 cases, 4 cases in grade 1, 2 cases in grade 1 in b = 800 s / mm ~ 2, 24 cases in grade 2 and 6 cases in grade 3, 4 cases in grade 3 and 4 cases in group mSENSE-DWI with b = 300 s / mm ~ 2 There were 3 cases in grade 5, 10 cases in grade 3 at b = 500 s / mm ~ 2, 20 cases in grade 4 and 2 cases in grade 5, 7 cases in grade 2 at b = 800 s / mm ~ 2, 23 cases in grade 3, 4 cases in 2 cases. The image quality of the mSENSE-DWI group was better than that of the conventional DWI group under the same b-value (the Z values were -5.578, -5.488 and -4.796 respectively in 3 different b value groups, P <0.01). The median ADC value of DWI group was (1.578 × 10 ~ (-3)), (1.390 × 10 ~ (-3)), (1.173 × 10 ~ (-3)) mm ~ 2 / s, the median ADC value of mSENSE-DWI group was 1.381 × 10 ~ (-3) and 1.242 × 10 ~ (-3) (1.136 × 10 ~ (-3)) mm ~ 2 / s. There was no significant difference in ADC value between the two groups (500,800 s / mm ~ 2) Z values were -0.873, -0.862, P values were 0.383, 0.388, respectively). Conclusion The application of mSENSE in liver DWI can obtain high quality images with no effect on ADC values of small lesions in HCC.