Cervical carcinoma with full-thickness stromal invasion: efficacy of dynamic MR imaging in the assessment of parametrial involvement.

The purpose of this study was to investigate the efficacy of dynamic MR imaging in the assessment of parametrial involvement by cervical carcinoma with full-thickness stromal invasion on thin-section oblique axial T2-weighted images. Dynamic MR images of 24 patients with cervical carcinoma with full-thickness stromal invasion on thin-section oblique axial T2-weighted images were evaluated with pathologic correlation. Dynamic MR imaging was performed using a turboFLASH, 3D-FISP, or 2D-FLASH technique. The imaging planes of dynamic MR imaging were oblique axial planes of the uterine cervix. Dynamic MR imaging was performed twice, once for the early phase (40 to 60 sec after the administration of contrast media) and once for the late phase (5 min). Contrast enhancement of the tumor was divided into six types. Type I, cervical stroma with low signal intensity surrounding a tumor with high signal intensity, was seen in the early phase of dynamic MR imaging; type II-RR, the hyperintense rim was seen from the early phase to the late phase; type II-RO, the hyperintense rim was seen in the early phase only; type II-OR, the hyperintense rim was seen in the late phase only; type II-O, the hyperintense rim was not seen at all; and type III, tumor invasion with high signal intensities was seen beyond the cervical stroma in the early phase of dynamic MR imaging. The numbers for each type of cervical carcinoma on dynamic MR images were as follows: type I, four parametrial sites; type II-RR, 0; type II-RO, 0; type II-OR, 13; type II-O, 14; and type III, one. Three-dimensional diameters (transverse, craniocaudal, and anteroposterior) of the primary tumor were measured using dividers. All parametrial sites of type I and type II-OR showed no parametrial involvement. One parametrial site of type III and three parametrial sites of type II-O showed parametrial involvement, and 11 of type II-O showed no parametrial involvement. None of the patients showed type I-RR or type II-RO. When type I and type II-OR were categorized as criteria of no parametrial involvement and type III and transverse diameters of 3.5 cm or over classified as type II-O were categorized as criteria of parametrial involvement, the rate of diagnostic accuracy was 95.8%. Dynamic MR imaging is considered to be substantially useful in the assessment of parametrial involvement with cervical carcinoma with full-thickness stromal invasion by thin-section oblique axial T2-weighted images.