In this particular video Dr. Stephen Graham, the owner of Graham Chiropractic which is located in Louisville, KY., discusses  what the differences between an MRI and an x-ray and when he refers patients for an MRI.

Dr.Graham reports that for most of his patients with back pain he takes a plain film x-ray.  These are low cost, typically $80, and have a very low dose of gamma rays. He says that these x-rays provide most of the information he needs to not only help him to ascertain a diagnosis, but also gives him information on what the best type of chiropractic adjustment to use. Dr. Graham states that some of the main benefits of the x-ray is that it shows thickness of the lumbar discs, shape of the vertebrae, and the alignment of the lumbar spine.  In addition, a plain film many times will reveal if there is a potential pathology that would require a further study.

Whereas an MRI shows what the disc looks like inside. It will confirm if there is premature disc degeneration (disc desiccation), disc bulges and or disc herniations.  It also details if there is spinal stenosis and the extent of it.  Pathologies are also better detected on an MRI most of the time.

Dr. Graham goes on to say that typically he will refer for an MRI if during the examination the patients exhibits signs of a herniated disc or a severely bulged disc. He reports that if the straight leg raise exhibits a painful response or if there is a loss of reflex or muscle weakness, often times this is indicative of a herniated disc and these patients should have an MRI.  Moreover, if he believes them to be a surgical candidate he will usually have them get this test run.

Finally, Dr. Graham states that an MRI has no bad side effects as it is a magnet and does not emit gamma rays.