Background: At our center and at others, some children with acute hematogenous osteomyelitis (AHO) are evaluated with multiple magnetic resonance imagings (MRIs) during their treatment. Do these serial MRI studies have a role in the management of AHO? We examine several clinical indications for ordering a repeat MRI and whether the imaging study resulted in a change in management.
Methods: A total of 59 children (60 cases) with AHO were imaged with more than 1 MRI. We retrospectively reviewed the MRI studies and hospital records to investigate whether the results of the MRIs prompted a change in clinical management (surgical exploration or drainage, biopsy, change in the course of antibiotics). We investigated several clinical indicators including C-reactive protein (CRP) levels, time since index study, anatomic location of infection, and blood cultures. Differences in the proportion of patients with specified clinical characteristics, whose repeat MRI resulted in a change in management, were assessed by the use of χ2 analysis.
Results: The median age of our patient population was 8.4 years; a total of 104 repeat MRI studies were undertaken on 59 children. Eleven (10.6%) of these studies prompted a change in patient treatment. Statistically significant indications for repeat MRI in changing clinical management included failure to improve clinically in 10 studies (21%, P<0.001), persistently elevated or increasing CRP levels in 11 MRI studies (52%, P<0.001), and the repeat study occurring within 14 days of the diagnostic MRI in 8 studies (29%, P=0.003).
Conclusions: The results of our study showed that additional MRI studies provide information that affected patient management in only a limited number of cases. Although repeat MRI does not have a role in routine surveillance in children with AHO undergoing treatment, it can be a useful adjunct to clinical evaluation in patients who do not respond to therapy or who have a persistently elevated CRP level.
Level of Evidence: Level IV, Therapeutic Study.