Magnetic resonance imaging of the female pelvis. New circularly polarized body array coil versus standard body coil.
OBJECTIVE
The authors compare the value of a new circularly polarized body array coil (BAC) system with a standard body coil (BC) for high-resolution magnetic resonance imaging of the female pelvis.


METHODS
Twenty patients with cervical cancer were examined with a BC and BAC. Imaging parameters were kept constant (sagittal T2-weighted turbo spin-echo: repetition time = 4000 mseconds; effective echo time = 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 lesion-to-organ delineation and overall image quality/ artifacts using a scale from 5 to 1 (excellent to poor). Signal-to-noise (S/N) ratios for different tissues (tumor, uterus, vagina, rectum, muscle, and fat) as 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 Gynecology 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 improved overall image quality (average ratings: BAC-4.3 points; BC-2.6 points; 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) was increased noticeably on BAC images. No significant difference was found for staging accuracy.


CONCLUSIONS
Circularly polarized BAC provide superior S/N and C/N ratios and improve lesion conspicuity compared with standard BC.
Scheidler
J
J
Department of Diagnostic Radiology, Ludwig-Maximilians University, Munich, Germany.
Heuck
A F
AF
Bruening
R
R
Kohz
P
P
Kimmig
R
R
Stehling
M K
MK
Reiser
M F
MF
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D010388:Pelvis / Q000473:pathology*; D011446:Prospective Studies; D014594:Uterine Neoplasms / Q000175:diagnosis*