Lower back pain is one of the most common reasons why people visit their doctor or go to urgent care. Severe low back pain may lead you to think something is seriously wrong with your lumbar spine. It is common for most doctors to advise imaging tests like MRI or X-ray to determine the cause of back pain or the patients wanting it to relieve their concerns. These are useful if your problem is due to a structural issue in the spine. But most back pain cases are mechanical in nature or the cause is not serious like a strained muscle, sprained ligament or poor posture and Degenerative Disc Disease; that can be extremely be painful and possibly limit your activity level. In such cases, imaging tests like MRI & X-rays fails to show you the complete picture and are probably not necessary.
Imaging tests should be recommended or mandatory when there are serious symptoms or red flags. Neurological symptoms like radiating pain into the buttocks and legs; abnormal reflexes; sensations of tingling, numbness or weakness; foot drop; loss of bowel or bladder. Co-existing medical conditions like cancer, fever, osteoporosis, diabetes, recent infection, use of immunosuppressant or steroids, previous spinal fracture or spine surgery and unexplained weight loss.
Many lower back pain cases improve in days or a few weeks with medication (Pain-Killers) and conservative treatment including physical therapy. Rarely is sub-acute (pain lasting between 4 and 12 weeks) or chronic back pain (pain lasting 3 months or longer) an indication of an urgent lumbar spine condition.
X-rays are helpful for evaluation of fracture, bony deformity including degenerative changes, sacroiliitis, disc and vertebral body height, and assessment of bony density and architecture. To analyse soft-tissue or disc damage, computed tomography (CT) or magnetic resonance imaging (MRI) scans may be needed. An electromyogram (EMG) helps find nerve and muscle damage.
X-rays and imaging studies are generally used to confirm your symptoms and exam results to identify the source of pain. X-rays and CT scans expose you to radiation, which can increase cancer risk. That’s especially worrisome to men and women of childbearing age, because it can expose testicles and ovaries to radiation. Furthermore, the tests often reveal spinal abnormalities that could be completely unrelated to the pain. Those findings can cause needless worry and lead to unnecessary follow-up tests and procedures such as injections or sometimes even surgery.
MRI & X-ray images cannot distinguish between subtypes of back pain and chronic issues. MRI findings do not match with intensity of pain and disability in case of discogenic back pain. Interpretive errors by radiologists make these reports extremely subjective which, can directly impact the diagnosis, treatment and clinical outcomes. These are only a few of the many shortcomings of referring to imaging tests as the primary mode of diagnosis.
This is the reason why doctors combine all their findings like symptoms, physical examination and imaging tests to confirm a diagnosis and then recommend an appropriate treatment plan. These imaging tests are enough to diagnose the cause of back pain but due to its pros and cons as mentioned earlier it should be recommended only when necessary.Thus, implementing a selective approach to low back imaging would provide better care to patients, improve outcomes, and reduce costs.
These imaging tests do not adequately diagnose condition of degenerated tissues as they are done in static position. But, patients often experience pain when they perform a certain task like – bending, walking or sitting. This is why some doctors recommend a Spine Function Test to show a more complete picture with detailed functional analysis (strength, mobility & balance). A spine function test can help identify the weak areas of the musculature and help doctors develop a more targeted treatment plan.
Dr.Shriya Patel (PT)