Magnetic resonance imaging. Application to family practice.
OBJECTIVE
To review indications, contraindications, and risks of using magnetic resonance imaging (MRI) in order to help primary care physicians refer patients appropriately for MRI, screen for contraindications to using MRI, and educate patients about MRI.


METHODS
Recommendations are based on classic textbooks, the policies of our MRI group, and a literature search using MEDLINE with the MeSH headings magnetic resonance imaging, brain, musculoskeletal, and spine. The search was limited to human, English-language, and review articles. Evidence in favour of using MRI for imaging the head, spine, and joints is well established. For cardiac, abdominal, and pelvic conditions, MRI has been shown useful for certain indications, usually to complement other modalities.


RESULTS
For demonstrating soft tissue conditions, MRI is better than computed tomography (CT), but CT shows bone and acute bleeding better. Therefore, patients with trauma or suspected intracranial bleeding should have CT. Tumours, congenital abnormalities, vascular structures, and the cervical or thoracic spine show better on MRI. Either modality can be used for lower back pain. Cardiac, abdominal, and pelvic abnormalities should be imaged with ultrasound or CT before MRI. Contraindications for MRI are mainly metallic implants or shrapnel, severe claustrophobia, or obesity.


CONCLUSIONS
With the increasing availability of MRI scanners in Canada, better understanding of the indications, contraindications, and risks will be helpful for family physicians and their patients.
Goh
R H
RH
Hamilton Health Sciences Corporation-General Division, Diagnostic Imaging Department, ON.
Somers
S
S
Jurriaans
E
E
Yu
J
J
D000328:Adult; D001847:Bone Diseases / Q000175:diagnosis / Q000000981:diagnostic imaging; D002543:Cerebral Hemorrhage / Q000175:diagnosis / Q000000981:diagnostic imaging; D000013:Congenital Abnormalities / Q000175:diagnosis / Q000000981:diagnostic imaging; D000075202:Contraindications; D003365:Costs and Cost Analysis; D005194:Family Practice; D006331:Heart Diseases / Q000175:diagnosis / Q000000981:diagnostic imaging; D006801:Humans; D017116:Low Back Pain / Q000175:diagnosis / Q000000981:diagnostic imaging; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging / Q000191:economics; D008297:Male; D009369:Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging; D010353:Patient Education as Topic; D018579:Patient Selection; D013122:Spinal Diseases / Q000175:diagnosis / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography