EDUCATION EXHIBIT 1445 Body MR Imaging at 3.0 T: Understanding the Opportunities and Challenges 1 Mara M. Barth, MD ● Martin P. Smith, MD ● Ivan Pedrosa, MD Robert E. Lenkinski, PhD ● Neil M. Rofsky, MD The development of high-field-strength magnetic resonance (MR) im- aging systems has been driven in part by expected improvements in signal-to-noise ratio, contrast-to-noise ratio, spatial-temporal resolu- tion trade-off, and spectral resolution. However, the transition from 1.5- to 3.0-T MR imaging is not straightforward. Compared with body imaging at lower field strength, body imaging at 3.0 T results in altered relaxation times, augmented and new artifacts, changes in chemical shift effects, and a dramatic increase in power deposition, all of which must be accounted for when developing imaging protocols. Inhomoge- neities in the static magnetic field and the radiofrequency field at 3.0 T necessitate alterations in the design of coils and other hardware and new approaches to pulse sequence design. Techniques to reduce total body heating are demanded by the physics governing the specific ab- sorption rate. Furthermore, the siting and maintenance of 3.0-T MR imaging systems are complicated by additional safety hazards unique to high-field-strength magnets. These aspects of 3.0-T body imaging rep- resent current challenges and opportunities for radiology practice. © RSNA, 2007 Abbreviations: FDA = Food and Drug Administration, FOV = field of view, NSA = number of signals acquired, RF = radiofrequency, SAR = spe- cific absorption rate, SE = spin echo, SNR = signal-to-noise ratio, TE = echo time, TR = repetition time RadioGraphics 2007; 27:1445–1464 ● Published online 10.1148/rg.275065204 ● Content Codes: 1 From the Department of Radiology, Beth Israel Deaconess Medical Center, 330 Brookline Ave, Boston, MA 02215. Presented as an education ex- hibit at the 2005 RSNA Annual Meeting. Received December 18, 2006; revision requested January 31, 2007; revision received March 14 and accepted March 23. N.M.R. has received research support from GE Healthcare and has served on the advisory board for Schering (Berlex) and as a consultant with CAD Sciences and EPIX Pharmaceuticals; all remaining authors have no financial relationships to disclose. Address correspondence to M.M.B. (e-mail: mbarth@bidmc.harvard.edu). See also the article by Akisik et al (pp 1433–1444) and the commentary by Sher (pp 1462–1464) in this issue. © RSNA, 2007 Note: This copy is for your personal non-commercial use only. To order presentation-ready copies for distribution to your colleagues or clients, contact us at www.rsna.org/rsnarights.