Whole-body MRI in Pediatric Patients with Chronic Recurrent Multifocal Osteomyelitis

Objective: To evaluate the clinical and radiological findings of the patients with chronic recurrent multifocal osteomyelitis (CRMO) and to present the benefits of using whole-body magnetic resonance imaging (WBMRI) in these patients and the changes we have made in the technique. Methods: A total of 45 patients who underwent WBMRI between 2017 and 2021 were included in the study. All WBMRI scans included coronal short tau inversion recovery (STIR), coronal T1W, and sagittal spinal STIR sequences. The examination time was 40 min on average. All WBMRIs were evaluated at two different time. At first assessment, only coronal STIR images were evaluated in all patients. In the second assessment, the same patients evaluated with all the sequences. The contribution of coronal T1W and sagittal STIR sequences to the diagnosis was investigated by comparing the first evaluation with the second evaluation. Thirty five patients were diagnosed with CRMO. The remaining 10 patients had other inflammatory, infective, and neoplastic diseases. The diagnosis of 15 patients with CRMO was based on bone marrow biopsy results. Also, biopsy was performed in 10 patients diagnosed as non-CRMO. Results: Most of the patients had multifocal bone lesions, particularly in the metaphyses adjacent to the epiphyseal region. The bones of the lower extremities were the most commonly affected. The mean delay in diagnosis was 17 months (0-96), and the follow-up period was 20 months (1-47) in a total of 35 patients, with a recurrence rate of 28%. In most patients (88%), lesions could be identified from coronal STIR images alone at the initial evaluation. However, in 5 patients whose diagnosis was missed when evaluated only from coronal STIR images, lesion identification and possible preliminary diagnosis were detected only with coronal T1W and sagittal STIR images in the second look. Conclusion: WBMRI is an important examination of systemic diseases such as CRMO that involve multiple sites. In addition to coronal STIR sequences, coronal T1-weighted and sagittal STIR sequences are important in identifying other infective-inflammatory diseases and particularly hematological malignant processes in the differential diagnosis of CRMO.