扩散加权成像对诊断前列腺癌的初步研究

目的 探讨基于多次激发回波平面成像(EPI)和二维空间选择激发EPI的快速高分辨扩散加权成像(DWI)对前列腺癌诊断的临床应用价值.资料与方法 对6例健康志愿者和13例经穿刺活检证实的前列腺癌患者进行常规和多序列DWI成像,分别测量各DWI序列扫描图像的信噪比(SNR)和表观扩散系数(ADC)值并进行比较分析.另将5例行前列腺癌根治术的整体前列腺病理标本与DWI显示病灶的部位、范围和数量进行对照分析.结果 与单次激发EPI相比,多次激发EPI提高了图像的空间分辨率和SNR (P＜0.05),二维空间选择激发EPI减少了扫描时间分辨率(P＜0.05).单次激发、多次激发和二维空间选择激发EPI-DWI序列采集的前列腺癌患者的ADC值与健康志愿者的ADC值差异均有统计学意义(P＜0.01).结论 基于多次激发和二维空间选择激发EPI的DWI技术可以提高前列腺图像的空间分辨率和SNR,有助于改善前列腺癌的诊断准确性.

Preliminary Research for the Diagnosis of Prostate Cancer by Using Diffusion-weighted Imaging

Purpose To assess the value of fast high-resolution diffusion-weighted imaging(DWI) based on multi-shot and 2D selective excitation echo planar imaging(EPI) in the diagnosis of prostate cancer.Materials and Methods 6 health volunteers and 13 patients with biopsy confirmed prostate cancer were examined by using the conventional T2WI and multi-sequence DWI.The signal to noise ratio(SNR) estimated from prostate central and peripheral zone and apparent diffusion coefficient(ADC) value estimated from prostate cancer focus and health volunteers were compared among single-shot EPI,multi-shot EPI and 2D selective excitation EPI.In addition,the overall prostate pathological specimens from 5 patients performed radical prostatectomy were compared with the lesion location,ranges and volumes from DWI.Results Compared with single-shot EPI,multi-shot EPI improved the spatial resolution and SNR(P < 0.05),while 2D selective excitation EPI improved the temporal resolution(P<0.05) and SNR(P<0.05),which was helpful to improve the diagnosis accuracy for small prostate cancer lesion.There were statistical significant differences of ADC values from single-shot EPI,multi-shot EPI,and 2D selective excitation EPI DWI between patients and healthy volunteers(P < 0.01).Conclusion Prostatic neoplasms;Diffusion magnetic resonance imaging;Diffusion weighted imaging;Echo-planar imaging;Apparent diffusion coefficient