General precautions and warnings
47
• Sequences in Normal Operating Mode shall be used only! During the scan patients might
perceive auditory sensations such as clicking or beeping. Adequate counselling of the
patient is advised prior to performing the MRI. The likelihood and intensity of auditory
sensations can be reduced by selecting sequences with lower specific absorption rate
(SAR) and slower gradient slew rates.
• Image artefacts are to be expected (refer to Fig. B).
• The above instructions should also be followed if areas of the body other than the head
are to be examined (e.g. knee, etc.). When lower extremities are to be examined, it is
recommended that the patient’s legs are positioned in the scanner first to minimize any
risk of weakening the implant magnet.
• The above instructions also apply for patients with bilateral cochlear implants or bilateral
auditory brainstem implants.
If the conditions for MR safety and the Safety Guidelines are not followed, injury to the
patient and/or damage to the implant may result!
Fig. A Head bandage to support fi xation of the
implant
Fig. B MR images obtained with a 1.5 T scanner
(8 year old child)
