MRI imaging is useful in diagnosing patients with suspected tumours, infection, occult fractures and for pre-operative assessment of patients who are indicated for surgery.
The role of MRI is very controversial in management of mechanical/non-specific low back pain. Scientific guidelines and algorithms agree that imaging for non-specific low back pain should be employed sparingly and judiciously and only in response to evidence-based indications.
A sequence of studies over 15 years has shown:
i. Routine imaging in the absence of clear indications does not provide useful diagnostic or prognostic information. The imaging does not help explain the cause of back pain. On the contrary, it can give false possibilities across the diagnostic work-up, gives unnecessary fear and anxiety to patients and can affect the behaviour of both patient and doctor, thus leading to misguided treatments, providing justification for all kinds of intervention including surgery, even though many of the abnormalities revealed through imaging have no causal role in symptoms
ii. That when employed without clear indications, imaging does not improve the clinical outcome and can lead to a worse outcome instead. The association between back symptoms and common imaging findings such as degenerative disc disease, facet joint arthropathy, even herniations or bulging is weak. It is difficult to distinguish between asymptomatic and symptomatic imaging. There is consistent medical data in that indicates that doctors cannot tell who is having back pain, or how severe the back pain is by the use of image studies. Other than fracture, infection, cancer and major disc herniations with obvious nerve root compression and appropriate clinical correlating findings, image findings do not indicate who is in pain, or how severe the pain is (ii, iii, iv, v, vi, vii, viii, ix, x, xi).
Dr. CHUN, Siu-yeung