Do I need a scan? "a picture tells a thousand words" - not really!
by Martin Krause
A scan, in it's self, will not improve anyone's condition. The purpose of a scan is to gain more information about the pathology. Sometimes this information may be irrelevant to the management of a patient's condition. For example, if you knocked your elbow on a door frame and suffered a bruise, which was already beginning to resolve, an ultrasound scan may show some minor soft tissue damage, but that was already obvious by the fact of the bruise, and the information gained from the scan has not helped nor changed the management of the bruise. Therefore, the main reason for getting a scan would be because there is concern that the presence of certain pathologies may lead to a change in the medical management. For example, sometimes a rolled ankle can be more than sprained ligaments, and may require surgey or immobilisation in a boot. If the therapists suspects this might be the case, then they will recommend or refer for a scan (probably an X-Ray) to check the integrity of the bones (especially the fibular and talar dome), because if there is no bony damage then the patient can be managed conservatively with taping, exercises, ultrasound, massage, joint mobilisations etc. However, if there is boney damage, for example, then it might be necessary for the ankle to be immobilised in a boot for three - six weeks, for example. This dramatically different medical management depends on the results of a scan, and it is therefore worth doing.
However, scans have no predictive value to the presence or severity of pain. Thirty-three articles reporting imaging findings, in the low back, for 3110 asymptomatic individuals were investigated for pathology. The prevalence of disk degeneration in asymptomatic individuals increased from 37% of 20-year-old individuals to 96% of 80-year-old individuals. Disk bulge prevalence increased from 30% of those 20 years of age to 84% of those 80 years of age. Disk protrusion prevalence increased from 29% of those 20 years of age to 43% of those 80 years of age. The prevalence of annular fissure increased from 19% of those 20 years of age to 29% of those 80 years of age. (Brinjikji, W et al Spine Published November 27, 2014 as 10.3174/ajnr.A4173). Hence, the results of imaging need to be assessed within the context of the entire clinical picture. Frequently too much emphasis is placed on the imaging not only by the clinician but also by the patient. Some people react to pathology seen on scanning as an affirmation of their problem and can either use it to gain clarity and become better or conversely become worse. Moreover, some people find imaging with inconclusive results as a 'panic moment' - "no one knows what is wrong".
Similarly, ultrasound imaging of the tendond has good predictive diagnostic and aids in clinical reasoning when it comes to full tears. However, with partial tears it is a totally different 'ball game'. Ultrasound is highly user dependent, with specifically trained musculoskeletal radiologists able to produce high-quality images that may provide more clinically relevant information than those produced by clinicians with less experience in imaging. Sean Docking, a leading tendon researcher at Monash University, cited 7 authors who found pathological tendon chnages in 59% of asymptomatic individuals, whereas he found that 52% of asymptomatic elite AFL sportsmen had tendon pathology on imaging! Furthermore, symptomatic individuals who improved clinically to the point of resuming play, weren't shown to have improvements on imaging. Again, the clinical context and the clinical reasoning can in many instances prove to be the 'gold standard' not the imaging itself, when considering management options.
Shoulder supraspintatus tendon pathology, in the abscence of trauma, is known, in many instances, to be a disorder of immune-metabolic compromise of the tendon and bursa. Imaging may show some changes in signal intensity but, unless it's a complete tear, it can reveal neither the intensity nor the severity of pain when taken outside of the clinical context. A thorough physical and subjective examination integrating all the clinical dimensions of the problem will have far greater value than any one single imaging modality.
Yet, imaging still should be used in instances of progressive rapid deterioration and suspected serious pathology which may require surgery and/or immediate medical intervention.
In summary, sometimes it is worthwhile getting a scan, because the information gained from that scan will determined the type of medical management that is employed. However, at other times, the scan may be unneccessary, because the information may be irrelevant or lead to an incorrect change in medical management, due to over-reporting of 'false positives'. You will be able to make this decision on the advice of your health care professional. On occasions it can actually be detrimental to have a scan, because some patients can become overly obsessed with the medical terms used to describe their scan results, which then can become the major focus for the clinician and the patient, rather than the more prefereable focus on their symptoms and functional abilities. For example, many people have lumbar buldging discs yet have no symptoms, yet sometimes when these patients have an MRI or CT scan, they can develop symptoms because they think they should have pain if the scan says so! Conversely, for some people the results of imaging can have a positive and reassuring affect. Therefore, it is very important to assess a clients attitude to scans before prescibing them so that the patient's expectations are managed appropriately, and not burdened by the additional, sometimes confusing, information supplied by a scan.
Uploaded : 10 October 2017
