The clinical use of magnetic resonance imaging in pyogenic vertebral osteomyelitis

Study Design. Retrospective chart review of 103 cases. Objectives. To describe the clinical use of magnetic resonance imaging in a pyogenic vertebral osteomyelitis. Summary of Background Data. Long delays in diag nosing pyogenic vertebral osteomyelitis of the spine have been shown in many reports. Magnetic resonance imaging has been advocated as the imaging method of choice in suspected spinal infections. The use, accuracy, and timing of magnetic resonance imaging in pyogenic vertebral osteomyelitis have not been reported in a large series. Methods. In 103 patients with pyogenic vertebral osteomyelitis who underwent magnetic resonance imaging at or before the time of diagnosis, the author reviewed the clinical findings and results of the magnetic resonance imaging, timing with respect to symptom duration and diagnosis, and accuracy of readings in detecting spinal infection. Follow-up magnetic resonance imaging reports also were reviewed. Results. Magnetic resonance imaging appeared to give the correct diagnosis or suggest pyogenic vertebral osteomyelitis as a possible diagnosis in 55% and 36% of cases, respectively, with less than 2 weeks of symptoms. After 2 weeks, the percentages of correct and possible diagnoses of pyogenic vertebral osteomyelitis increased to 76% and 20%, respectively. Magnetic resonance imaging was obtained within 1 month of the start of symptoms in 73% of cases. The diagnosis was made within 1 month in the most cases as well, compared with a 2- to 6-month delay in most series. Follow-up magnetic resonance images often gave impressions of progressive disease, whereas the clinical picture appeared to improve. Conclusions. Magnetic resonance imaging is valuable in suggesting the diagnosis even very early in the clinical course of pyogenic vertebral osteomyelitis. Its use may eliminate significant delays in diagnosis. The use of magnetic resonance imaging in following the therapeutic response remains to be defined.