中文摘要：

目的 探讨小视野DWI ADC直方图鉴别透明细胞肾癌与非透明细胞肾癌的价值.方法 回顾经手术及病理证实为肾细胞癌,术前接受过肾脏MRI平扫及小视野DWI检查的64例患者.透明细胞肾癌46例（47个病灶）,非透明细胞肾癌18例（19个病灶）.记录透明细胞肾癌与非透明细胞肾癌的ADC直方图参数,包括ADC平均值（ADCmean）、ADC中位数（ADCmedian）、ADC第5百分位数（ADC_5th）、ADC第25百分位数（ADC_25th）、ADC第75百分位数（ADC_75th）、ADC第95百分位数（ADC_95th）、偏度及峰度值,并采用独立样本t检验（正态分布）或Mann-Whitney U检验（偏态分布）比较.采用ROC评价ADC直方图参数鉴别诊断不同肾癌的效能.结果 透明细胞肾癌ADC值直方图以负偏态分布为主,非透明细胞肾癌以正偏态为主.透明细胞肾癌的ADC平均值、ADC中位数、ADC_5th、ADC_25th、ADC_75th和ADC_95th均高于非透明细胞癌,差异有统计学意义（P均〈0.05）;二者的偏度值差异有统计学意义（P〈0.05）,峰度值差异无统计学意义（P〉0.05）.ADC_75th鉴别透明细胞及非透明细胞肾癌的效能最高,ROC下面积为0.987,以1.81×10^-3mm^2/s为截断值,敏感度及特异度分别为100.0％和94.7％.结论 小视野DWI ADC直方图鉴别透明细胞肾癌与非透明细胞肾癌有一定价值,ADC_75th具有较高诊断效能.

英文摘要：

Objective To explore the utility of ADC histogram analysisin differentiation of clear cell renal cell carcinoma（ccRCC）and non-clear cell renal cell carcinoma（non-ccRCC）with r-Fov DWI. Methods Sixty-six renal tumors（46 patients with 47 ccRCCs and 18 patients with 19 non-ccRCCs）in 64 patients, who underwent preoperative routine renal MRI sequences and r-FOV DWI, were retrospectively evaluated. The whole-lesion ADC values derived from histogram anlysis（including ADC mean, ADC median, ADC_5th, ADC_25th, ADC_75th, ADC_95th, skew and kurtosis）were measured for each patient. All parameters between ccRCC and non-ccRCC were compared by using the Student＆#39;s t test or Mann-Whitney U test. ROC analysis was used to assess the diagnostic performance of ADC histogram in distinguishing the two groups. Results The postive skewness of ADC histograms were mostly seen in the non-ccRCC group, while the negtative skewness were present in the majority of ccRCCs. The skewness was significantly higher in non-ccRCCs than those of ccRCCs（P〈0.05）. Mean ADC, median ADC, 5th percentile ADC, 25th percentile ADC, 75th percentile ADC and 95th percentile ADC（all P〈0.05）were significantly lower in non-ccRCC . There was no significant difference of Kurtosis between two groups（P〉0.05）. 75th percentile ADC achieved the highest AUC（0.987）in differentiating ccRCC and non-ccRCC, whena cutoff value was 1.81×10^-3 mm^2/s. The sensitivity and specificity were 100.0%and 94.7%. Conclusion ADC histograms of r-FOV DWI may be helpful to differentiate ccRCC from non-ccRCC, and the diagnostic accuracy of 75th percentile ADC is highest.