ORIGINAL ARTICLES In Vivo Prostate Magnetic Resonance Imaging and Magnetic Resonance Spectroscopy at 3 Tesla Using a Transceive Pelvic Phased Array Coil Preliminary Results Hee-Won Kim, PhD,*§ David L. Buckley, PhD,†§ David M. Peterson, MS,* G. Randy Duensing, PhD,‡¶ Jim Caserta, MS,* Jeffrey Fitzsimmons, PhD,* and Stephen J. Blackband, PhD,†§ Abstract: Magnetic resonance (MR) systems operating at 3 Telsa (T) and above have demonstrated considerable potential in human studies, offering improved signal-to-noise ratio and spectral resolu- tion. However, because of radiofrequency limitations and concerns, and the lack of large volume body coils, most studies have been limited to the head. In this study we describe the design and construction of a transceive pelvic phased array coil with which MR images and spectra of the human prostate at 3 T have been obtained. Comparison with 1.5 T instruments with different hardware config- urations is difficult; however, in a preliminary comparison the signal-to-noise ratio is improved in phantoms and humans when compared with a 1.5 T receive-only pelvic phased array coil, and high quality spectral resolution is demonstrated through the delin- eation of the citrate quadruplet in localized 1 H prostate spectra. Higher fields offer the potential for MR prostate studies without the use of an endorectal coil. Key Words: transceive, phased-array, high field, 3.0 Tesla, prostate, MRI, MRS (Invest Radiol 2003;38: 443– 451) M agnetic resonance imaging (MRI) and spectroscopy of the pathologic prostate gland have shown considerable potential in determining the stage of the disease, differenti- ating benign prostatic hyperplasia from carcinoma, for mon- itoring the course of therapy, guiding biopsy, radiation ther- apy treatment planning, and tumor volume measurement. 1–8 Limitation in the signal-to-noise ratio (SNR) on conventional 1.5 T clinical systems using body coils has driven the devel- opment of endorectal (ER) coils, recently used in combina- tion with pelvic phased array (PPA) coils. 9 –12 This has facilitated high spatial and temporal resolution imaging and 1 H spectroscopy on volumes of the order of a few millili- ters. 13–16 By combining the ER coil with the PPA coil, the increased SNR over the prostate offered by the ER coil is combined with the large field of view over the pelvis offered by the PPA coil. 17 The ER coil is contraindicated in a number of patients 4 (eg, for patients examined shortly after surgery, particularly after abdominal perineal resection for rectal cancers or after radiation therapy for the pelvis). In some cases, it is better not to use an ER coil to avoid structural deformation of the prostate peripheral zone, which is often compressed by an ER coil. The ER coil also causes signal hyperintensity near the rectum and neighboring peripheral zone. The signal hyperin- tensity and tissue deformation can make diagnostic interpre- tation difficult. Ways of improving the SNR without causing tissue deformation or signal hyperintensity in the prostate are desirable. From the *Departments of Radiology, †Neuroscience and ‡Electrical and Computer Engineering, and the §UF Brain Institute, University of Flor- ida, Gainesville, FL; ¶MRI Devices Corp., Gainesville, FL; and the National High Magnetic Field Laboratory, Tallahassee, FL. Presented at the 7th Annual Meeting of ISMRM in Philadelphia, Pennsyl- vania, May 1999. Received August 2, 2002, and accepted for publication, after revision, November 19, 2002. Supported by University of Florida McKnight Brain Institute, the National High Magnetic Field Laboratory, and grant funding from the NIH (R01 DK51014, R01 NS41094-01, and P41 RR16105). Reprints: Hee-Won Kim, PhD, Department of Radiology, University of Florida, 1600 SW Archer Rd, Gainesville, FL 32610. E-mail: hwkim@ufl.edu Copyright © 2003 by Lippincott Williams & Wilkins 1521-737X/03/3807-0443 DOI: 10.1097/01.RLI.0000065425.29042.8d Investigative Radiology • Volume 38, Number 7, July 2003 443