3-T MRI in the preoperative evaluation of depth of myometrial infiltration in endometrial cancer.

The objective of our study was to evaluate the diagnostic accuracy of 3-T MRI in determining the depth of myometrial infiltration in patients with endometrial cancer.Fifty-two patients (43 postmenopausal) with histopathologically proven endometrial carcinoma underwent preoperative 3-T MRI. The following sequences were performed: axial T1 fast spin-echo (FSE); axial, parasagittal, and paracoronal T2 FSE; paracoronal 3D T1 inversion recovery gradient-echo after contrast administration; and parasagittal fat-suppressed T1 FSE. All patients underwent a hysterectomy. The MRI findings were compared with histopathology results. The quantity and degree of artifacts were evaluated.. MRI performed on a 3-T unit was in agreement with histopathology in assessing the depth of invasion in 86.4\% (44/52) of the patients with a mean sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of 83.5\%, 93.9\%, 77.8\%, 92.2\%, and 89.7\%, respectively. Performance values were also assessed for single stages of myometrial infiltration. For the detection of an intramucosal lesion (MRI, 12/52; histopathology, 6/52), sensitivity was 100\%; specificity, 86.9\%; PPV, 50\%; NPV, 100\%; and accuracy, 88.5\%. For the detection of myometrial infiltration that was less than 50\% (MRI, 12/52; histopathology, 16/52), sensitivity was 62.5\%; specificity, 94.4\%; PPV, 83.3\%; NPV, 85\%; and accuracy, 84.6\%. For the detection of myometrial infiltration that was greater than 50\% (MRI, 28/52; histopathology, 30/52), sensitivity was 93.3\%; specificity, 100\%; PPV, 100\%; NPV, 91.7\%; and accuracy, 96.2\%. The following artifacts were found: abdominal wall movement, nine patients (not affecting image quality); peristalsis, 16 patients (two deeply affecting, one affecting, and 13 scarcely affecting); magnetic susceptibility artifact, four patients (not affecting); chemical shift, 20 patients (four scarcely affecting and 16 not affecting); and dielectric effect, six patients (four deeply affecting and two affecting).In evaluating the depth of myometrial infiltration in patients with endometrial cancer, 3-T MRI showed high diagnostic accuracy-equivalent to that of 1.5-T MRI reported in the literature. Artifacts did not significantly affect image quality.