基于体素内不相干运动的MR扩散加权成像对前列腺癌诊断价值的初步研究

目的：初步评价基于体素内不相干运动(IVIM)理论的MR扩散加权成像对前列腺癌的诊断价值。材料与方法连续性回顾性分析具有完整临床资料、MR IVIM扩散加权成像检查和穿刺活检病理结果的前列腺癌患者45例及非前列腺癌者13例，IVIM扩散加权成像采用8个b值(0、50、100、150、200、400、600、800 s/mm2)，利用软件双指数函数方式计算信号衰减曲线得出纯水分子扩散系数D值、灌注相关扩散系数D*值及灌注分数f值，并且获取各参数图。采用独立样本t检验比较前列腺癌与非癌外周带组织间各值的差异。结果前列腺癌区域的D值、D*值及f值分别为(0.83±0.14)×10-3 mm2/s、(5.88±1.21)×10-3 mm2/s及(14.3±4.7)%，非癌前列腺外周带组织D值、D*值及f值分别为(1.30±0.23)×10-3 mm2/s、(6.25±1.10)×10-3 mm2/s及(15.4±3.8)%，其中前列腺癌区域D值明显低于非癌外周带组织，两者之间有统计学差异(P=0.000)。D*值及f值无统计学差异。D值ROC曲线下面积为0.952，敏感性为100%，特异性为66.7%。结论基于MR体素内不相干运动理论MR扩散成像能提供关于前列腺癌组织扩散及灌注方面更多的信息，D值对前列腺癌的诊断具有重要的价值。

Investigation of prostate cancer using intravoxel incoherent motion MR imaging

Objective: To evaluate the diagnostic value of intravoxel incoherent motion diffusion-weighted imaging for prostate cancer.Materials and Methods: Forty-ifve patients with prostate cancer and 13 patients without prostate cancer underwent magnetic resonance imaging. DWI was performed by using 8 b values (0, 50, 100, 150, 200, 400, 600, 800 s/mm2). Biexponential fits were applied to diffusion decay curves by special software to calculate pure molecular-based diffusion coefifcient (D), pseudo diffusion coefifcient of perfusion (D*) and perfusion fraction (f) on the basis of the IVIM model, parameter maps were also calculated for all parameters. Independent samples groupt tests were performed to evaluate the statistical signiifcance between cancerous tissue and noncancerous tissue.Results:The D, D* and f values in cancerous tissue were (0.83±0.14) ×10-3 mm2/s, (5.88±1.21)×10-3 mm2/s and (14.3±4.7)%, respectively. The D, D* and f values in noncancerous tissue were (1.30±0.23)× 10-3 mm2/s, (6.25±1.10)×10-3 mm2/s and (15.4±3.8)%, respectively. The D value was signiifcantly (P=0.000) lower in cancerous tissue. D* and f values were not signiifcantly different in both tissues. The area under the receiver operating characteristic-analyses for D value was 0.952, sensitivity and specificity were 100%, 66.7%, respectively. Conclusion:Intravoxel incoherent motion diffusion-weighted imaging may offer additional information about diffusion and perfusion in prostate cancer. Pure molecular-based diffusion coefifcient (D) has an important value in diagnosing prostate cancer.