[Physical parameters in the use of MRI tomography. Limitation due to physiologic reactions and guidelines. Radiation Protection Commission].
OBJECTIVE
The standards and regulations concerning the protection of patients and operator staff within the context of MRI are compiled. Resulting consequences regarding physical parameters are evaluated.


METHODS
The static magnetic field, heating effects caused by RF-fields and acoustical noise are outlined. The actual boundaries of these parameters are compared against the relevant published standards. Peripheral stimulation limits due to pulsed gradient fields have been determined in a new clinical study.


RESULTS
Many parameters recommended for the normal operating mode are already exceeded during routine MRI. Referring to our clinical study, we found that limits recommended in the MRI relevant standards are unnecessarily conservative and can actually be doubled.


CONCLUSIONS
The applicable national and international standards and regulations show (at least partly) that serious differences in the definition of terms and values exist. The application of these standards would be much easier if they were made uniform. The values defined in the MR-specific standards should be adapted to actual knowledge concerning patients' safety.
Frese
G
G
Siemens AG, Medizinische Technik, GG MR, Erlangen.
Hebrank
F X
FX
Renz
W
W
Storch
T
T
D004307:Dose-Response Relationship, Radiation; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000009:adverse effects*; D011832:Radiation Injuries / Q000517:prevention & control; D011835:Radiation Protection / Q000379:methods*