AbdELMonem M. El-Sharkawy1, Di Qian1,2, Paul A. Bottomley1,2, William A. Edelstein1
1Russell H. Morgan Department of Radiology & Radiological Science, Johns Hopkins University, Baltimore, MD, USA; 2Electrical & Computer Enginnering, Johns Hopkins University, Baltimore, MD, USA
Accurate and independent real-time measurement of RF power deposition is essential for MRI safety. We designed and built a six channel MR compatible, real-time power profiling system suitable for MRI up to 400MHz. The bench-calibrated system is highly linear over a 90dB dynamic range and does not interfere with scanner operation. RF power deposition was measured in eleven volunteers in a 3T scanner during whole-body MRI. The results showed considerable differences between the true power delivered and that estimated by the scanner supporting the view that scanner specific absorption rates do not accurately reflect true individual RF exposure.