Metallic objects within or on the body can interfere with the magnetic field required to obtain optimal MR images. Although many successful MR studies can be performed on patients with surgically implanted metallic devices, there are a few devices which should be kept out of the MRI room. These include (but are not limited to):
Deep brain stimulators
Brain aneurysm clips
Endovascular aortic grafts (< 6 weeks old)
Heart stents (<6 weeks old)
Drug infusion pumps (including insulin pumps)
Most surgical wires, sutures, rods, and clips (for example, those used for gallbladder surgery, hysterectomy, breast biopsy, or to fix broken bones) are perfectly safe in the MRI machine. Please ask us about your individual case.
Retained bullet fragments or BBs may be safe to put in the MRI machine. These are addressed on an individual basis.
Metallic fragments in the eye can become heated in the magnet. If you have ever had metal in your eye, even if it has been removed, we may perform a quick x-ray of your eyes before letting you in the MRI room to make sure all the metal is gone.
Finally, if your study requires the administration of intravenous contrast, we will need to make sure you are a suitable candidate. We will need laboratory documentation of adequate kidney function within 30 days of your MRI if you have any of the following:
- Age over 60
- High blood pressure
- History of kidney failure
- Solitary kidney
- History of kidney cancer
- Kidney transplant
- History of severe liver disease
- Liver transplant
If you are a dialysis patient, you may need special arrangements if you need to receive intravenous contrast.
Screening breast MRI
If you are scheduled for a screening breast MRI, the study should ideally be performed during the second week of your menstrual cycle (that is, two weeks after the completion of your last period), although any time between day 5 and day 17 is acceptable.
Screening patients who take supplemental estrogen for any reason (birth control, control of menopausal symptoms, vaginal creams, etc.) should discontinue use for at least 30 days prior to the MRI.
Diagnostic breast MRI
Diagnostic breast MRI is usually performed for one of two reasons:
- Pre-surgical planning for a newly diagnosed cancer
- Work-up of a specific problem (such as bloody nipple discharge or new lump)
For these patients, the MRI can be performed at any time during the menstrual cycle.