Objective: The purposes of this study were to determine the feasibility of diffusion-weighted imaging (DWI) with a single-shot echo-planar sequence and parallel technique for depicting endometrial cancer and to examine the role of this technique in preoperative assessment.
Subjects and methods: A total of 31 patients were recruited for MRI evaluation of suspicious endometrial lesions found on transvaginal sonography. Twenty-four of the patients were proved to have endometrial cancer (patient group), and seven to have benign diseases (control group). The MRI examinations included diffusion-weighted single-shot echoplanar sequences and contrast-enhanced T1-weighted 3D fat-suppressed spoiled gradient-echo sequences. The apparent diffusion coefficient of endometrial cancer in the patient group and of normal endometrium in the control group were measured on the apparent diffusion coefficient map of each diffusion-weighted image and compared for the two groups. In the patient group, myometrial invasion was evaluated with the two sequences. The diagnostic accuracy rates of each pulse sequence were compared.
Results: The mean apparent diffusion coefficient of endometrial cancer was 0.864 x 10(-3) mm2/s and that of benign endometrial lesions was 1.277 x 10(-3) mm2/s. The difference between the two groups was significant (p = 0.0058). The diagnostic accuracy for myometrial invasion was 61.9% for DWI and 71.4% for gadolinium-enhanced T1-weighted 3D fat-suppressed spoiled gradient-recalled echo images. In five cases, DWI provided information about tumor extent and depicted the tumor focus, findings that changed preoperative staging.
Conclusion: DWI performed with parallel imaging technique has potential as a method for differentiating benign from malignant endometrial lesions. It also provides valuable information for preoperative evaluation and should be considered part of routine preoperative MRI evaluation for endometrial cancer.