Multishot echoplanar MR imaging of the female pelvis: comparison with T2 weighted fast spin echo imaging

To compare the usefulness of multishot echoplanar imaging(EPI) with T2-weighted fast spin-echo imaging(FSE) for the evaluation of female pelvic organs and pathologic conditions. Twenty-nine patients with pelvic lesion underwent MR imaging(GE Medical Systems) using a pelvic array coil(GE Medical Systems). Axial EPI(TR/TE=3D2,000/80, 6mm slice thickness, 2.5mm gap, multishot 16) and T2-weighted FSE(TR/TE-3,400/117,5mm slice thickness, 1.5mm gap, ETL-12) were obtained. Overall image quality, the parametrial venous plexus, anatomy of the uterine zone and outer margin, identification of the ovaries, pelvic pathologic condition, and frequency of artifact, as seen on EPI and FSE imaging were reviewed separately by two radiologists. For overall imaging quality, EPI was superior to FSE in 14% of patients(4/29), equal in 24%(7/29), and inferior in 62%(18/29). For delineation of the parametrial venous plexus, EPI was superior to FSE in 79%(23/29). For uterine zonal anatomy and the outer margin, EPI was inferior to FSE in 55%(16/29) and in 45%(13/29), respectively. On EPI, visualization of the ovary was rated superior to FSE in 0%(0/9), equal in 52%(15/29), and inferior in 48%(14/29). Conspicuity of pelvic pathologic lesions was superior in 14%(4/29), equal in 52%(15/29), and inferior in 48%(14/29). Image distortion and susceptibility artifacts were seen on EPI in six cases, while on FSE motion artifacts were seen in two cases. As EPI is inferior to FSE in overall image quality, delineation of the normal anatomy of pelvic organs and conspicuity of pelvic lesions, it cannot replace FSE for imaging the female pelvis. However, because EPI reduces imaging time, further technical progress in this area may stimulate the use of ultrafast imaging of the femal pelvis.=20