If you visit a clinician be it orthopaedic surgeon or a neuro-surgeon and complain of back ache you are more than likely to be advised to have an MRI.

Low back pain is a very common condition. The Need for diagnostic imaging for patients with low back pain has often been exaggerated. ‘Evidence indicates that routine imaging is not associated with clinically meaningful benefits but can lead to harms’, reports Annals of Internal Medicine.

Usually diagnostic imaging in this condition should be indicated only if low back pain is associated with progressive neurologic deficits or signs or symptoms that suggest a serious or specific underlying condition. This evidence-based recommendations from the American College of Physicians (ACP) and the American Pain Society (APS) appear to be grossly neglected. Routine imaging does not seem to improve clinical outcomes and exposes patients to unnecessary harms.

Overuse of imaging imposes severe financial burden on patients who already suffer lower productivity due to the menacing low back pain. Reducing unnecessary tests or ineffective treatments decrease the costs associated with low back pain. In addition to the direct costs imaging also causes additional expenses by leading to additional tests, follow-up, and referrals. It may also result in an invasive procedure of limited or questionable benefit.

The appropriateness of many of the low back imaging studies obtained in clinical practice has long been questioned. The ACP/APS low back pain guideline recommends selective imaging for patients in whom it is clinically indicated.

There are numerous factors that explain why routine imaging does not seem beneficial. Most lumbar imaging abnormalities are common in persons without low back pain and are only loosely associated with back symptoms. Although advanced imaging can detect more and smaller abnormalities, these abnormalities are not necessarily clinically relevant. This means a rapid MRI need not always be of greater practical value than radiography for evaluating low back pain.

Many abnormalities detected with advanced imaging are so common in asymptomatic persons that they could be viewed as normal signs of aging. The presence of imaging abnormalities need not mean that the abnormalities are responsible for symptoms.

Acute low back pain has a favourable natural history and the expected yield of routine imaging is low. Most patients show significant improvements in pain and function in the first 4 weeks; routine imaging is unlikely to improve on this. Imaging results rarely affect treatment plans. Thus they often have a low impact on clinical outcomes.

Routine imaging is associated with potential harms:

• Lumbar radiography and CT contribute to cumulative low-level radiation exposure. They may promote the development of cancer.

• The use of iodinated contrast in lumbar CT is associated with hypersensitivity reactions and nephropathy (disease associated with the kidneys).

• The average radiation exposure from lumbar radiography is 75 times higher than for chest radiography. This is particularly harmful to young woman because of the proximity to the gonads (sex glands). The amount of female gonadal irradiation from lumbar radiography is supposed to tantamount to having chest radiography daily for several years.

Most clinicians routinely order imaging for all cases of lower back pain even in the absence of a clear clinical indication though ACP/APS guideline suggests a trial of management without imaging in adults with no risk factors other than older age. The use of advanced imaging modalities like MRI and CT scans is skyrocketing. A large number of clinicians hastily jump to these modalities irrespective of any guidelines.

Patient expectations and preferences about diagnostic testing also add to the cause. They expect a clear diagnosis for their low back pain. Some attach a clinician’s decision to not obtain imaging with low-quality care. There are patients who think that their pain is not legitimate or important if the clinician doesn’t order for imaging. Wanting diagnostic testing is a frequent reason for repeated office visits for chronic back pain. There are ones who insist that they need imaging even after the physician explains that it would be unnecessary.

The potential solutions include:

• Clinicians should adhere to the ACP/APS recommendations on use of imaging so as to reduce overuse. Most patients do not need immediate imaging, and an initial trial of therapy before imaging is warranted in many cases. 

• Advanced imaging should be reserved for serious situations, i.e. only when the results are sure to influence clinical decision making. Conditions like major trauma, severe neurologic compromise, or vertebral infection qualify for being imaged using an MRI or CT scanner. In the absence of strong risk factors for cancer and lack of neurologic signs, initial imaging with lumbar radiography and evaluation of erythrocyte sedimentation rate (ESR) is a reasonable approach.

• Patients should be educated about the pros and cons of imaging. Face-to-face information with patient hand outs, self-care education books, online materials, mass media educational campaigns help.

Source: ‘Diagnostic Imaging for Low Back Pain: Advice for High-Value Health Care from the American College of Physicians’: Annals of Internal Medicine.

Source-Medindia