扩散峰度成像直方图分析在前列腺癌诊断及Gleason评分评估中的价值

The clinical value of histogram analysis of diffusion kurtosis imaging in prostate cancer and the correlation between histogram parameters and Gleason score

目的探讨扩散峰度成像(DKI)直方图分析在前列腺癌与非前列腺癌鉴别诊断及Gleason评分评估的应用价值。方法回顾性分析2017年5月至2018年5月就诊于北京医院21例可疑前列腺癌患者,完成MRI扫描和经直肠MR引导下前列腺穿刺活检。21例患者共有病灶31个,前列腺癌15个,非前列腺癌16个。前列腺癌的15个病灶中,Gleason评分3+3分3个、3+4分6个、4+3分2个、≥8分4个。患者均行前列腺MRI平扫。测量病灶的非高斯模型校正后表观扩散系数(Dapp)和表观峰度系数(Kapp)的平均值及直方图参数,最终获取Dapp和Kapp的平均值、10%位数、25%位数、50%位数、75%位数、90%位数、最小值、最大值、峰度以及偏度。采用独立样本t检验比较前列腺癌与非前列腺癌间平均值以及各直方图参数的差异,采用Spearman秩相关分析评价直方图参数与前列腺癌Gleason评分的相关性。结果前列腺癌病灶Dapp的平均值、10%位数、25%位数、50%位数、75%位数、90%位数、最小值以及最大值均低于非前列腺癌病灶,差异有统计学意义(P均<0.05);前列腺癌Kapp的平均值、50%位数、75%位数、90%位数以及最大值均高于非前列腺癌,差异有统计学意义(P均<0.05)。Kapp的90%位数与最大值与Gleason评分呈正相关(r值分别为0.630、0.565,P值均<0.05)。结论DKI直方图分析在前列腺癌的诊断和评估前列腺癌恶性程度中具有一定的临床应用价值。

Objective To explore the value of diffusion kurtosis imaging (DKI) histogram analysis for differential diagnosis of prostate cancer and noncancerous foci and the correlation between histogram parameters and Gleason score. Methods Twenty-one patients were retrospectively enrolled in Beijing Hospital from May 2017 to May 2018. All subjects underwent Philips 3.0 T MR scanning. The pathologies were confirmed by in-bore MR-guided biopsy. Finally, 31 lesions were collected (two lesions each from 10 patients), including 15 prostate cancer and 16 noncancerous foci (benign prostatic hyperplasia and prostatitis). ROI was drawn manually by two experienced radiologists. All the lesions were measured mean apparent diffusion coefficient (Dapp), mean apparent kurtosis coefficient (Kapp) and their histogram parameters, the averages of two measurements were used to be calculated. The values of these parameters in cancer and noncancerous foci were compared using independent-samples t test. The Spearman test was used to evaluate the correlation of these parameters and Gleason scores of prostate cancer. Results Mean Dapp, 10th Dapp, 25th Dapp, 50th Dapp, 75th Dapp, 90th Dapp, minimum Dapp, maximum Dapp, mean Kapp, 50th Kapp, 75th Kapp, 90th Kapp, maximum Kapp between prostate cancer and noncancerous foci were statistically significant (P<0.05). 90th Kapp (r=0.630, P<0.05) and maximum Kapp (r=0.565, P<0.05) increased with the Gleason scores increasing. Conclusion Histogram analysis of DKI model is valuable for diagnosing and assessing aggressiveness of prostate cancer.