Cost-effectiveness of Magnetic Resonance Imaging in Cervical Spine Clearance of Neurologically Intact Patients With Blunt Trauma.

STUDY OBJECTIVE: Use of magnetic resonance imaging (MRI) for cervical clearance after a negative cervical computed tomography (CT) scan result in alert patients with blunt trauma who are neurologically intact is not infrequent, despite poor evidence in regard to its utility. The objective of this study is to evaluate the utility and cost-effectiveness of using MRI versus no follow-up in this patient population. METHODS: A modeling-based decision analysis was performed during the lifetime of a 40-year-old individual from a societal perspective. The 2 strategies compared were no follow-up and MRI. A Markov model with a 3% discount rate was used with parameters from the literature. Base cases and probabilistic and sensitivity analyses were performed to assess the cost-effectiveness of the strategies. RESULTS: The cost of MRI follow-up was $11,477, with a health benefit of 24.03 quality-adjusted life-years; the cost of no follow-up was $6,432, with a health benefit of 24.08 quality-adjusted life-years. No follow-up was the dominant strategy, with a lower cost and a higher utility. Probabilistic sensitivity analysis showed no follow-up to be the better strategy in all 10,000 iterations. No follow-up was the better strategy irrespective of the negative predictive value of initial CT result, and it remained the better strategy when the incidence of missed unstable injury resulting in permanent neurologic deficits was less than 64.2% and the incidence of patients immobilized with a hard collar who still received cord injury was greater than 19.7%. Multiple 3-way sensitivity analyses were performed. CONCLUSION: MRI is not cost-effective for further evaluation of unstable injury in neurologically intact patients with blunt trauma after a negative cervical spine CT result.

Utility of MRI for cervical spine clearance after blunt traumatic injury: a meta-analysis.

OBJECTIVES: To quantify the rate of unstable injuries detected by MRI missed on CT in blunt cervical spine (CS) trauma patients and assess the utility of MRI in CS clearance. METHODS: We undertook a systematic review of worldwide evidence across five major medical databases and performed a meta-analysis. Studies were included if they reported the number of unstable injuries or gave enough details for inference. Variables assessed included severity, CT/MRI specifications, imaging timing, and outcome/follow-up. Pooled incidences of unstable injury on follow-up weighted by inverse-of-variance among all included and obtunded or alert patients were reported. RESULTS: Of 428 unique citations, 23 proved eligible, with 5,286 patients found, and 16 unstable injuries reported in five studies. The overall pooled incidence is 0.0029 %. Among studies reporting only obtunded patients, the pooled incidence is 0.017 %. In alert patients, the incidence is 0.011 %. All reported positive findings were critically reviewed, and only 11 could be considered truly unstable. CONCLUSIONS: There is significant heterogeneity in the literature regarding the use of imaging after a negative CT. The finding rate on MRI for unstable injury is extremely low in obtunded and alert patients. Although MRI is frequently performed, its utility and cost-effectiveness needs further study. KEY POINTS: • There were 16 unstable injuries on follow-up MRI among 5286 patients. • The positive finding rate among obtunded patients was 0.12 %. • The positive finding rate among alert, awake patients was 0.72 %. • MRI has a high false-positive rate; its utility mandates further studies. • The use and role of "confirmatory" tests shows wide variations.