扩散加权成像在宫颈癌诊断中的初步应用

目的：分析正常子宫宫颈3层结构及宫颈癌的扩散加权成像（DWI）特点，探讨其及相应的表观扩散系数（ADC）对宫颈癌的诊断价值。材料与方法：对15例非子宫疾病女性患者及12例宫颈癌患者在1．5TMR上行盆腔DWI成像。DWI序列的b值为0、800s／mm^2。在DWI及ADC图中观察正常宫颈的层次结构，并比较不同分层的ADC值；在DWI图像中测量宫颈癌病灶相对于闭孔内肌的信号强度比值（SIR），并与常规T1WI及T2WI同法获得的SIR比较；测量宫颈癌组织的ADC值并与对照组比较。结果：在对照组中有73％的病例（11／15）在DWI图像中可以分清宫颈的3层结构，而在ADC图中则为100％。3层结构的ADC值分别为（1．83±0．37）×10^-3、（1．23±0．24）×10^-3及（1．87±0．24）×10^-3mm^2，s（内膜层、结合带及肌层），3者间有显著差异。所有宫颈癌组患者的宫颈正常分层结构均消失，在DWI上均表现为弥漫高信号，ADC值为（0．86±0．08）×10—3mm^2／s，癌灶明显低于正常宫颈各层结构的ADC值。DWI、T1WI及T2WI图像中宫颈癌病灶相对于闭孔内肌的SIR分别为2．97±0．69、0．06±0．02及1．96±0．32，3者间有显著差异。结论：正常宫颈及宫颈癌在DWI及ADC图中均具有一定特征，其中DWI能较常规序列更加突出宫颈癌病灶，有助于准确诊断。

Diagnosis of uterine cervical cancer by diffusion-weighted imaging: a preliminary research

Objective： To evaluate the feasibility of diffusion-weighted imaging （DWI） and apparent diffusion coefficient （ADC） in diagnosis of cervical cancer. Methods and Materials： Twelve female patients with cervical cancer and 15 female patients without cervical disease were included in this study. Preoperative MRI examinations were performed at a Philips 1.5T MR scanner. In addition to routine T1WI and T2WI, DWI with b factor of 0 and 800s/mm^2 was also performed. ADC values of different zones of the uterine cervix were compared. The signal intensity ratio（SIR） between cervical cancer and internal obturator muscle in DWI was compared with those in T1WI and T2WI. The ADC values of tumor and normal cervical tissue were measured respectively and were compared. Results： The three zones of cervix can be distinguished in 75% of the normal cervix on DWI, while increased to 100% on ADC map, the ADC values of cervical endometrium, conjunctive zone and muscular layer was （1.83±0.37）×10^-3, （1.23±0.24）×10^-3 and （1.87±0.24）×10^-3mm^2/s respectively. All the cervical cancer appeared high signal intensity without clear layers of the cervix as compared with normal cervical tissue, and the ADC value of tumor was statistically lower （0.86±0.08）×10^-3mm^2/s than that of normal tissue. The SIR between cervical cancer and internal obturator muscle on DWI, T1WI and T2WI was 2.97±0.69, 0.06±0.02 and 1.96±0.32 respectively with statistical difference. Conclusion： DWI and ADC measurement has a potential ability to differentiate between cancer and normal tissue of the uterine cervix.