Imaging & Back Pain - Should I get a Scan?
In Australia, approximately 70-90% of people will suffer from low back pain at some point in their lives. In 2018, it was estimated that at any one time, 4 million Australians (16% of the population) were experiencing back pain. Being so common, it is no wonder that back pain is one of the most common complaints presenting to physiotherapists on a daily basis. For some patients, their symptoms can be extremely debilitating, or may take months to settle. Whether someone should get a scan for their back pain is often a topic of conversation, and invariably comes up in the majority of cases. In recent times due to the increased access to medical imaging, it is also quite common for patients to present for physiotherapy already having had scans ordered by their GP.
I have back pain – do I need a scan?
Low back scans are not a necessary part of your diagnosis and treatment, particularly early on. With the enormous variability in individuals and their back pain, it can be hard to know whether you should have a scan for your back pain, what type of scan, and when.
When should I get a scan?
Imaging in cases of low back pain is not recommended when your symptoms have been present for less than 12 weeks. This is because:
1. Most cases of low back pain will resolve in this time frame regardless of what your scan results show
2. Getting a scan in this timeframe will usually not make a difference to the treatment you will receive
3. In some cases, scan results may result in referral for unnecessary interventions, when your back pain would have likely recovered within 12 weeks with conservative management
4. Imaging such as X-rays and CT scans expose you to radiation, so unnecessary scans expose you to unnecessary radiation
a. A lumbar spine X-ray is the equivalent of up to 65 chest X-rays! (Tannor, 2017)
b. A lumbar spine CT is the equivalent of up to 365 chest X-rays – that is like adding 2.5-5 years of background radiation! (NSW Agency for Clinical Innovation)
5. MRI’s do not expose you to radiation, but do come at an associated cost, which may be unnecessary if performed too early in your rehabilitation
It is also important to understand that all imaging, in all areas of the body, can pick up a lot of false positives. That is, the scan will pick up any anomalies or variations from “the normal healthy model” which will be reported on by the radiologist (because it is their job to report on everything they see). However, these findings may or may not be related to your symptoms. It is important to understand that pathology does not equal pain! In the case of low back pain, findings of disc bulges or pinched nerves are quite common, but are also commonly not implicated in your symptoms. There is also no way to know when these abnormal findings occurred – those disc bulges could have been there for 20 years prior to you first ever feeling pain in your back!
Imaging may in fact be necessary for a small proportion of people with low back pain prior to 12 weeks, for example, in cases where the condition is deteriorating rather than improving, in the presence of concerning neurological symptoms, or when there is a suspicion of a red flag condition. In these cases, the scan should be used to confirm a specific diagnosis, and not as a fishing expedition.
How do I know whether I am someone who needs a scan now?
A thorough physical examination by your physiotherapist will assist in determining whether you need a scan, what type of scan, and when it should be performed. A scan may then be requested to confirm a diagnosis and to inform further treatment. Once you’ve had your scan, your physiotherapist will also be able to tell you whether your results are relevant to your current symptoms, and if the course of treatment should change based on your results.
If you’d like to talk to a physiotherapist about your back pain, contact us here.