AN AUDIT OF MAGNETIC-RESONANCE-IMAGING IN THE PEDIATRIC ORTHOPEDIC SETTING

Aims. To determine when magnetic resonance imaging (MRI) is helpful in the management of a selected group of paediatric orthopaedic patients . Methods. A retrospective analysis of 131 MRI scans was undertaken wi th allocation into seven categories based on clinical presentation. Re sults. MRIs performed for spinal, congenital and intraarticular pathol ogy, as well as for growth plate assessment correlated well with subse quent clinical and/or surgical findings. Three of ten MRIs (30%) incor rectly assessed whether a foreign body was present with a sensitivity of 0.60 and specificity of 0.80. Three of 20 MRIs (15%) could not accu rately distinguish between oedema/effusion and frank infection. Here s ensitivity was 1.00 and specificity was 0.73. MRIs performed for asses sment of tumours were accurate with respect to margins and extent. Ass essment of pathology with MRI was never the indication for MRI, thus i t was not surprising that in four of 27 soft tissue tumours (sensitivi ty of 0.88 and specificity of 0.63) MRI did not correlate with subsequ ent histological findings. Conclusions. MRI plays an important role in the assessment of a wide range of musculo-skeletal pathology. MRI doe s not, and could not be expected to, replace the need for incisional b iopsy for tumour diagnosis. It must be used with caution where tissues have been previously explored for foreign bodies. Interpretation of M RI in musculoskeletal infection must consider its tinting in the evolu tion of the patient's infection.