MRI of the pelvis in women: 3D versus 2D T2-weighted technique

The purpose of this study was to compare triplanar 2D T2-weighted turbo spin-echo MR images with reformatted images from a 3D T2-weighted turbo spin-echo sequence in analogous planes with respect to acquisition time, image quality, artifacts, and lesion detection.

Forty-four consecutively enrolled women referred for pelvic MRI participated in the study. The protocol included 2D T2-weighted turbo spin-echo sequences in the axial, coronal, and sagittal planes and a single sagittal 3D T2-weighted turbo spin-echo sequence. The acquisition times of the 2D and 3D sequences were calculated. The sagittal 3D data sets were reformatted at 2-mm slice thickness in each plane and compared with the 2D data sets with respect to image quality, artifacts, and lesion detection.

The mean acquisition time for the 3D sequence (419 seconds) was significantly shorter than acquisition time for the 2D sequences in three planes (728 seconds) (p < 0.0001). The readers favored the 3D reformats for cervical contrast (p = 0.005); otherwise, there was no significant difference between the 3D reformats and 2D data sets with regard to image quality and lesion detection. The 3D reformats were preferred with respect to respiratory (p < 0.001) and bowel (p < 0.001) motion.

The 3D approach with multiplanar reconstructions is a promising tool for imaging the female pelvis because of time savings without compromise of image quality, the diagnostic information obtained, and the versatility of reconstructing images in any orientation.