ADC值和标化 ADC值诊断前列腺癌恶性程度价值的比较

目的：比较表观扩散系数（ADC）值和标化ADC值在诊断前列腺癌恶性程度中的价值。方法回顾性分析经病理证实的34例前列腺癌的弥散加权成像（DWI）扫描结果。测量患者49个癌灶及外周带正常区域的ADC值，计算癌灶标化 ADC值。根据病理Gleason评分，49个癌灶分为：≤6分（低危组）、7分（中危组）、≥8分（高危组）共3组。对各组ADC值之间和标化ADC值之间的差别及ADC值和标化ADC值与Gleason评分之间的相关性进行统计学分析。结果前列腺癌 ADC值及标化ADC值3组整体差异均有统计学意义（P＜0．01），但两两比较ADC值在中危组与高危组之间差异无统计学意义（P＞0．05），而标化ADC值在各组间差异均有统计学意义（ P＜0．05）。ADC值（ r＝－0．546，P＝0．000）和标化 ADC 值（ r＝－0．575，P＝0．000）与Gleason评分均呈负相关。在比较前列腺癌各组的ROC曲线下面积时，标化ADC值与ADC值之间的差异无统计学意义（P＞0．05），但当特异性调整至100％时，标化ADC值在区别低危组与中危组、低危组与高危组时较ADC值具有更高的灵敏性（47．5％ vs ．5．6％、78．2％ vs ．50．9％）。结论 ADC值和标化ADC值与Gleason评分均呈负相关，但标化ADC值在诊断前列腺癌恶性程度方面可能具有更高的效能。

Comparison between ADC and standardized ADC value in diagnosing malignancy degree of prostate cancer

Objective To compare the value of apparent diffusion coefficient (ADC) value and the standardized apparent dif‐fusion coefficient (ADC) value in diagnosing malignancy degree of prostate cancer .Methods Diffusion weighted imaging (DWI) results of 34 patients with prostate cancer proved pathologically were retrospectively analyzed .The ADC values in 49 lesions and normal peripheral zones of the prostates of the patients were measured .Then ,ADC values of the lesions were calculated .According to the results of Gleason score ,the lesions were divided into 3 groups:Gleason score≤6 (low‐risk group) ,Gleason score=7 (inter‐mediate‐risk group) and Gleason score≥8 (high‐risk group) .Statistical analysis was performed to evaluate the differences of the ADC values and sADC values in three groups ,and to evaluate the correlation between Gleason score and ADC value or sADC value . Results There were statistically differences overall in ADC values and sADC values of the three groups (P<0 .01) .There was no difference between the intermediate‐risk and high‐risk group in ADC values (P> 0 .05) ,however ,there were difference between sADC values of three groups each other (P< 0 .05) .ADC values (r= -0 .546 ,P=0 .000) and sADC values (r= -0 .575 ,P=0 .000) showed all negative correlation with Gleason score .There were no differences between sADC values and ADC values of three groups in areas under the receiver operating characteristic curve (AUCs) (P>0 .05) .However ,when change the specificity to 100% ,sADC had higher sensitivity than ADC values (47 .5% vs .5 .6% ,78 .2% vs .50 .9% ) in differentiating low‐risk from inter‐mediate‐risk group ,and low‐risk from high‐risk group .Conclusion ADC value and sADC value showed all negative correlation with Gleason score ,but sADC value may be of higher performance in diagnosing malignancy degree of prostate cancer .