Does Your Image Have Your Back?
What does your image say about you?
As primary care practitioners we are constantly trying to remain up to date with evidence based practice (clinical expertise, best research evidence, patient values and preferences). On a daily basis we will hear about an individual’s experience with previous diagnoses via imaging and work to change behaviours and prejudices about what they have commonly learnt or even read about.
Let us tell you the latest about medical imaging and Low Back Pain and briefly explore the role of medical imaging in clinical practice.
Medical imaging is the technique and process of creating a visual representation of the body for clinical analysis and medical intervention. Disclaimer, medical imaging just as x-ray, ultrasound and magnetic resonance imaging (MRI) etc, do have an integral place in clinical practice in ruling in and out red flag pathologies (cancer, fracture, infection etc.)
What is "Normal"?
Degenerative changes are commonly found in spine. Even amongst the asymptomatic population (those experiencing no low back back symptomatology) according to this systematic literature review.
These changes do become more prevalent as we do age. Not dissimilar to grey hairs and wrinkles.
For example, disc bulges were identified in 30% of those 20 years of age to 84% of those in their 80’s. While disc protrusions in 29% of 20 year olds to 43% of 80 year olds. Degenerative findings were also found in 37% of 20 year olds who were asymptomatic and in 96% of individuals in their 80’s. (1)
“Imaging findings of spine degeneration are present in high proportions of asymptomatic individuals, increasing with age. Many imaging-based degenerative features are likely part of normal aging and unassociated with pain. These imaging findings must be interpreted in the context of the patient's clinical condition.” (1)
Now that we are starting to get a new appreciation of what is ‘normal’ in the body, it might be time to start changing beliefs and behaviours regarding low back pain and imaging respectively.
Should I get a scan?
Low back pain (LBP) is common. 80% of the population will at least experience LBP in their lifetime.
From here we categorise low back pain into 3 categories:
Specific LBP (1% of cases, imaging necessary to rule out sinister red flag pathology),
5% of LBP cases resulting in neurological deficits and
Nonspecific low back pain (NSLBP) (90-95% of cases, imaging questionable).
From the percentages listed above, it may seem imaging may be over utilised in most cases of LBP we see in clinical practice.
Brinjikji W, Luetmer PH, Comstock B, et al. Systematic literature review of imaging features of spinal degeneration in asymptomatic populations. AJNR Am J Neuroradiol 2015; 36(4): 811-6.