Do I Need An MRI? – April 2019
by Michael Wang, MD
MRI stands for Magnetic Resonance Imaging and is the best imaging technique for soft tissues.
On the other hand, x-ray, is suited best for bones and CT is somewhere in between providing some information on both soft tissues and bone.
In general, MRI is the most preferred imaging technique for evaluating soft tissue musculoskeletal questions such as ligaments, tendons, muscles, cartilage, labrum, discs, and nerves.
In addition, MRI is also the best technique for imaging the brain, liver, kidneys, pancreas, and reproductive organs.
MRI is NOT a substitute for being evaluated by a health care professional. MRI provides a snapshot in time and evaluates structure and not usually function. Qualified health care professionals evaluate function when they examine the patient and it is important to use all information to form a diagnosis.
Below is a list of typical indications for MRI.
|Ligament tear (ACL, PCL, MCL, LCL)|
|Muscle or tendon injury|
Q: Is an x-ray enough?
A: Health care professionals will often order x-rays as an initial study to exclude fractures. X-ray will not reliably demonstrate soft tissue damage. If there is a concern for soft tissue injury MRI should be performed.
In the example below, the x-ray is normal, there is no fracture (A). The MRI, however, demonstrates a complete ACL tear (B).
In another example, the spine x-ray is normal (C), but MRI demonstrates a large herniated disc resulting in pain and nerve impingement (D).