Patient: Can a torn meniscus be identified and diagnosed by a MRI? My mom had a lung cancer operation and (knock wood), has been free and clear for 6 years ,had a lot of x rays…oncologist specifically said to avoid CT scans and x rays….so, she injured an already torn meniscus and reinjured it the other day..she is a strong 78 yrs young….so, can an MRI detect problems in her knee? Thanks.
Doctor: A MRI is probably the best test available for assessment of meniscus tears of the knee.Absoloute contraindications to testing would include:PacemakerAneurysm clips that have not been tested in a magnet by manufacturers. The clinician must obtain details on the aneurysm clip and provide that information to the MRI technologist.Cochlear implantsFragments of metal within the body (especially if near the orbits or spineInfusion pumpsRelative contraindications to an MRI would include:Ventilated patient (Patients needs to be placed on a MRI compatible ventilator)Recent hardware placement (unless absolutely emergent it is recommended to wait 6 weeks to allow scar formation around implants)Penile and valve prosthesis (Most of these prosthesis are MRI compatible. The physician should be aware of the type of prosthesis the patient has had and provide this information to the technologist who will then do some research to see if it is safe.Pregnancy: We try to avoid scanning in the first trimester since we are not sure if there are any adverse effects to MRI. Pregnant women never receive the contrast agent gadolinium.Claustrophobic or anxious patients can not tolerate the MRI scanner.Obese patients may not fit into the small opening of the scanner. In addition the maximum weight that the MRI table can sustain is 350 lbs.Aside from the above constraints on MRI the patient should be aware that an average MRI of the takes 20 to 30 minutes to perform. As a result, it is not the study of choice in emergent situations or in extremely unstable patients. Also MRI is very motion sensitive. If the patient is moving around, the study will be degraded and essentially will be unreadable.I hope this helps