MAGNETIC-RESONANCE-IMAGING OF THE FEMALE PELVIS - NEW CIRCULARLY-POLARIZED BODY ARRAY COIL VERSUS STANDARD BODY COIL

RATIONALE AND OBJECTIVES. The authors compare the value of a new circu larly polarized body array coil (BAC) system with a standard body coil (BC) for high-resolution magnetic resonance imaging of the female pel vis. METHODS. Twenty patients with cervical cancer were examined with a BC and BAC. Imaging parameters were kept constant (sagittal T2-weigh ted turbo spin-echo: repetition time = 4000 mseconds; effective echo t ime = 99 mseconds; 160 x 160 mm field of view; 256 x 256 matrix; 0.63 x 0.63 mm pixel size; 4-mm slice thickness). Images were scored for le sion-to-organ delineation and overall image quality/artifacts using a scale from 5 to 1 (excellent to poor). Signal-to-noise (S/N) ratios fo r different tissues (tumor, uterus, vagina, rectum, muscle, and fat) a s well as contrast-to-noise (C/N) ratios between tumor and (1) uterus, (2) vagina, and (3) rectum were calculated. Magnetic resonance tumor staging was performed according to the International Federation of Gyn ecology and Obstetrics (FIGO) classification, RESULTS. Using the BAC, S/N and C/N ratios increased significantly compared with the BC (S/N: 2.7-3.4-fold increase for all organs evaluated, P < 0.001; C/N: tumor versus uterus 2.4-fold, P < 0.01; tumor versus vagina 6.1-fold, P < 0. 001; tumor versus rectum 3.1-fold, P < 0.01). This resulted in an impr oved overall image quality (average ratings: BAC-4.3 points; BC-2.6 po ints; P < 0.001), Lesion-to-organ delineation (average ratings: BAC 4. 3-4.1 points, BC 3.5-2.7 points for all organs evaluated; P < 0.001) w as increased noticeably on BAC images. No significant difference was f ound for staging accuracy. CONCLUSIONS. Circularly polarized BAC provi de superior S/N and C/N ratios and improve lesion conspicuity compared with standard BC.