To MRI or not to MRI?

In my June BCMJ article, I introduced my patient Bob. He had been rear-ended in a motor vehicle collision, and I reviewed existing medical literature for evidence to develop an initial treatment plan. At the outset, Bob and his lawyer had requested magnetic resonance imaging (MRI) scans of his head and neck. This article deals with MRI requests. I will revisit the Official Disability Guidelines (ODG) for evidence to direct the appropriate use of MRI. 

In Bob’s first visit, we had established injuries that included:

1. Grade 1 concussion

2. Grade 2 flexion extension neck injury

Bob was tested with a Standardized Concussion Assesment Tool (SCAT) for baseline cognitive function. 

In the second visit, Bob no longer had a headache. His neck remained stiff and sore, and he complained of low-grade neck pain with episodic moderate pain radiating from his neck to his mid-back. His pain and stiffness had worsened over time, but he was not experiencing weakness and numbness. He took acetaminophen for the first few days in order to sleep comfortably. 

I re-evaluated Bob with the SCAT. It remained unchanged. Examination of his neck and shoulders showed numerous trigger points. His neck range of motion was full, but he complained of discomfort at the end point of forward and right flexion. Axial loading of his neck in right flexion reproduced his pain. My diagnosis remained “mild concussion resolved and a grade-two cervical flexion extension injury.” I recommended plain films of his neck with flexion extension views.

Bob’s lawyer had sent him to our first visit with requisitions for head and neck MRIs to be performed at a private clinic. Bob again asked for the MRIs to be ordered. I reassured him that normally in cases such as his, MRIs would not be ordered. Bob was adamant that the MRIs be ordered and reaffirmed that they would be paid for by his lawyer, who felt it was important for Bob’s claim that they be done. I offered to discuss the appropriateness of the MRI requests with Bob’s lawyer. I referred to the Official Disability Guidelines (ODG) and obtained the latest guideline related to the appropriate use of MRIs. ICBC is now providing free access to the ODG for all physicians in British Columbia.

The ODG recommends plain films of the cervical spine for patients suffering whiplash injury with any evidence of neurological deficit or persistent pain. Lateral flexion and extension views may demonstrate instability of the spine. Any patient with a minimal fracture of the cervical spine should have a computed tomography (CT) scan to evaluate the status of the neural arch.

The ODG recommends the following indications for MRI:

• Chronic neck pain (i.e., after 3 months of conservative treatment)—radiographs normal, neurologic signs or symptoms present.

• Neck pain with radiculopathy, if severe or progressive neurologic deficit.

• Chronic neck pain—radiographs show spondylosis, neurologic signs or symptoms present.

• Chronic neck pain—radiographs show old trauma, neurologic signs or symptoms present.

• Chronic neck pain—radiographs show bone or disc margin destruction.

• Suspected cervical spine trauma—neck pain, clinical findings suggest ligamentous injury, radiographs, and/or CT “normal.”

• Known cervical spine trauma—equivocal or positive plain films with neurological deficit.

The ODG recommends the following indications for MRI in head injury:

• To determine neurological deficits not explained by CT.

• To evaluate prolonged interval of disturbed consciousness.

• To define evidence of acute changes superimposed on previous trauma.

Bob clearly did not meet the ODG recommendations for MRIs of his neck or head. An MRI has a limited role in the clinical management of whiplash and minor concussion. Indiscriminate use of MRIs may in fact confuse matters by the identification of abnormalities which have little clinical significance. 

The ODG is based on American data and reflects the standard of care in the United States. For the standards of care in Canada, physicians generally refer to the Canadian CT head rule for patients with minor head injury[1] and the Canadian C-spine rule for radiography in alert and stable trauma patients.[2] The Canadian guidelines focus mostly on CT scanning, which is the more appropriate test following plain film imaging. The Canadian guidelines also do not recommend the use of MRIs for this type of case. 

A comparison of the Canadian guidelines and the ODG recommendations may warrant future discussion in another article. Canadian guidelines are considered to be cost-effective but may lack comprehensiveness, whereas some other countries, particularly the US, may have more comprehensive and more expensive recommendations. 

This will be my last article as ICBC medical community liaison. My goal was to increase communication between ICBC and the physicians of British Columbia. This was achieved thanks to the response of many physicians who have corresponded with me over the past year. I enjoyed and appreciated the opportunity to deal with many interesting and challenging issues regarding the treatment and management of ICBC claimants. I wish ICBC’s new medical community liaison all the best and the continued support of the profession. In the interim, if you have any questions for ICBC relating to the care of injured claimants, please contact medinquiries@icbc.com.

—Martin Ray, MD