Reduced power magnetic resonance spectroscopic imaging of the prostate at 4.0 Tesla

✍ Scribed by Jamie Near; Cesare Romagnoli; Robert Bartha

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 542 KB
• Volume: 61
• Category: Article
• ISSN: 0740-3194
• DOI: 10.1002/mrm.21845

✦ Synopsis

Abstract

Proton magnetic resonance spectroscopic imaging (MRSI) of the prostate has been described at 1.5 T and 3 T as a means of localizing prostate cancers with high sensitivity and specificity. This technique could be improved by increasing the field strength further; however, it has not been described in detail above 3 T. To address the increase in B~1~ and SAR at high field strengths, a new protocol is described for reduced power STEAM MRSI of the prostate at 4.0 Tesla, using a pelvic surface coil array for RF transmission and reception, and a solid, reusable endorectal coil for reception only. The optimal STEAM sequence timing parameters for observation of the strongly coupled citrate spin system were determined through simulation to be echo time (TE) = 27 ms and mixing time (TM) = 27 ms, and the results were verified in vitro. Power reduction was achieved by applying the VERSE method to each of the three slice selective pulses in the STEAM sequence, and the B~1~max and SAR were reduced by 43% and 36%, respectively. Finally, in vivo spectroscopic imaging data were acquired from a prostate cancer patient, demonstrating the detection of citrate, choline, and creatine with 0.37 cc nominal resolution in a 10 minute scan. Magn Reson Med 61:273–281, 2009. © 2009 Wiley‐Liss, Inc.