What is Medical Imaging?
A patient with spinal pain, shoulder pain or knee pain (amongst others) may be referred for some form of investigation by their doctor or physiotherapist. This may often be in the form of a scan, otherwise known as medical imaging. This could include an MRI scan, x-ray or ultrasound, to name but three. There is often a belief amongst patients that some form of scan is essential for diagnosis and treatment as it will “show” what the cause of the pain to be.
However, we now know from research that patients without any symptoms can also demonstrate significant findings on various types of scan. The results of any scan should be individually discussed with a patient based on their presenting complaint and symptoms. In a large number of cases, any form of medical imaging or scan is simply not needed to aid diagnosis and management.
There have been a number of research studies in the last few years that have looked to investigate whether healthy (asymptomatic) people have the same findings on medical imaging as those people with pain. This has led to some very interesting findings, such as those below:
Cervical Spine (Neck)
Nakashima et al. (2015) Abnormal findings on magnetic resonance images of the cervical spines in 1211 asymptomatic subjects. SPINE.
In this study of 1211 people who had no pre-existing neck pain, it was shown that 87% of people in the study aged between 20 – 70 had some evidence of changes to the intervertebral discs of their spine on an MRI scan.
Girish et al (2011) Ultrasound of the shoulder: asymptomatic findings in men. American Journal of Roentology.
This study used ultrasound scan as a way of visualising structures around the shoulder joint. 51 men were included, and the results showed that 96% of participants demonstrated some form of shoulder “abnormality” on ultrasound. This included 78% of patients with evidence of bursitis (bursal thickening) and 22% who had a tear of their rotator cuff muscles despite having no symptoms.
Lumbar Spine (Lower back)
Brinjikji et al (2015) Systematic Literature Review of Imaging Features of Spinal Degeneration in Asymptomatic Populations. American Journal of Neuroradiology.
This systematic review of previous research studies included over 3000 participants without any pre-existing low back pain. The results of the review demonstrated that 37% of adults aged between 20-30 and some form of change to their intervertebral discs. This include(s) disc bulges, disc degeneration and disc herniation. This percentage rose for every decade of life to over 96% of patients aged over 80.
Frank et al (2015) Prevalence of Femoroacetabular Impingement Imaging Findings in Asymptomatic Volunteers: A Systematic Review. Arthroscopy.
This systematic review included studies that used medical imaging (MRI and x-ray) to examine for changes in the shape of the hip joint (known as CAM, PINCER or Labral pathology) The review included the results of 2,114 hip scans in people without hip joint pain. This review demonstrated that 37% of participants had CAM deformity, 67% had PINCER deformity and 68% had an injury to the Labrum (a rim of cartilage around the hip joint) However, all included participants had no hip joint pain.
Culvenor et al (2018) Prevalence of knee osteoarthritis features on magnetic resonance imaging in asymptomatic uninjured adults: a systematic review and meta-analysis. British Journal of Sports Medicine.
This systematic review of 5, 397 MRI scans of patients without any knee pain demonstrated that 4 – 14% of adults up to the age of 40 had features of osteoarthritis on an MRI scan. The review also showed that in adults over the age of 40 evidence of osteoarthritis was seen in up to 43% of included participants despite them having no knee pain.
Foot & Ankle
Symeonidis et al (2012) Prevalence of interdigital nerve enlargements in an asymptomatic population. Foot Ankle International.
In this ultrasound study of 48 pain-free volunteers, 54% had thickening of the nerves (known as neuroma) that run between the toes. Interestingly. in 35.4% of cases this was found in both feet. This was found despite all participants having no foot or ankle pain.
O’Neil et al (2017) Anterior Talofibular Ligament Abnormalities on Routine Magnetic Resonance Imaging of the Ankle Foot and Ankle Orthopaedics.
The anterior talo-fibular ligament (ATFL) is a ligament of the ankle. An ankle sprain is one of the more common reasons that people present to A&E departments. However, in this study of 320 MRI scans of the ankle, it was shown that 37% of participants had abnormalities of the ATFL without any history of ankle injury or pain.
Patients often feel that a scan will help identify the exact cause of their pain and that diagnosis can only be confirmed with the results of a scan. However, as we have seen here, we see similar findings in people without pain. The results of any scan should be taken in context of the patient’s pain and symptoms. It is important to note that many physiotherapy and medical treatments are successful for pain based on a clinical diagnosis and management plan. A scan may be needed in specific cases, but the physiotherapist or doctor should always explain why this is the case and then take time to reassure and explain the findings of the scan to you.