《3T MRI in clinical practice》.pdf

CME Earn ? Category 1 CME credits from this series: Refer to page XX for more information. CME Earn 1 Category 1 CME credit from this series: Refer to page 17 for more information. CATEGORY 1 CATEGORY 1 Continuing Medical Education Continuing Medical Education 3T MRI in clinical practice Lawrence N. Tanenbaum, MD, FACR agnetic resonance (MR) scan- ning began to make an impact M in the clinical practice setting in the mid 1970s. At introduction the most common systems operated at a field strength of 0.6T and there was credible doubt that more powerful magnets would be feasible, particularly for whole-body (beyond the brain) imaging needs. Even- tually, technological advances made high-field MR imaging practical, and systems operating at 1.5T have become the current clinical benchmark. New sys- tems sold today at lower field strengths are open designs designed for larger or claustrophobic patients. While there once was a significant market for closed systems operating at 1.0T due to lower cost, the decreasing cost differential with that 3T systems make up 25% of new Specific absorption rate 1.5T and market demands have all but high-field MR purchases. Specific absorption rate (SAR) is a eliminated these systems from new pur- Fueling the shift in interest from 1.5 measure of energy deposited by an RF chase considerations. to 3T from primarily a research device field in a given mass of tissue. SAR is Over the last several years, systems to clinical practice validates that what established by the International Elec- operating at higher fields have become was once considered very high-field MR trotechnical Commission (IEC) to not more prevalent, particularly at research (3T) is practical, feasible, and, indeed,