[Measurement of noise levels in MR tomography at 1.5 Tesla]

The noise levels at the isocentrum of an MR apparatus with a field strength of 1.5 Tesla was measured during various sequences. The rapid switching of the gradients exerts effects on the gradient coils, which result in the development of noise as from a loudspeaker. Measurements were carried out using gradients of 3 and 9.3 mT/m with head and body coils and a variety of sequences. The noise level depended largely on the type of sequence and, under extreme conditions, may attain 96 dB. Because of the short exposure times, we do not consider it necessary to use any form of protection. During the examination of patients with damaged hearing, some protection may be advisable.