Magnetic Resonance Imaging (MRI) of the Head What Affects the
Test Reasons you may not be able to have the test or why the
results may not be helpful include: - Being pregnant. An MRI
test is not usually done during pregnancy even though the strong
magnetic field is not known to be harmful. - Having medical
devices with metal. The MRI magnet may cause these devices to
not work right or to have problems during an MRI scan. This test
may not be done if you have: - An Reference intrauterine device
(IUD) Opens New Window in place. - Metal parts or clips in the
head or eye. - A Reference pacemaker Opens New Window. - An
Reference implantable cardioverter-defibrillator (ICD) Opens New
Window. - Certain types of artificial limbs. - A medicine
infusion pump in place. - Being unable to lie still during the
test. |By:||Reference Healthwise Staff||Last Revised: Reference
December 9, 2010| |Medical Review:||Reference Kathleen Romito,
MD - Family Medicine Reference Paul D. Traughber, MD -
Diagnostic Radiology