DYNAMIC GADOLINIUM-ENHANCED SUBTRACTION MR-IMAGING - A SIMPLE TECHNIQUE FOR THE EARLY DIAGNOSIS OF LEGG-CALVE-PERTHES DISEASE - PRELIMINARY-RESULTS

Purpose. To determine whether the simple technique of dynamic gadolini um-enhanced subtraction MR imaging, which is available on standard MR units, can detect ischemia of the femoral head in children with early Legg-Calve-Perthes disease (LCP). Materials and methods. Bone perfusio n of eight hips in four patients (mean age 7.5 years) was studied usin g dynamic gadolinium-enhanced subtraction MR imaging at the onset of p roven LCP (with initial negative plain films). Enhancement of subtract ed images was compared with that on standard MR images and with bone s cintigraphy findings. Results. Subtraction MR imaging depicted ischemi a as a widespread absence of enhancement and was in good agreement wit h bone scintigraphy. The subtraction technique improved the sensitivit y and the specificity of MR imaging in two children. Furthermore, subt raction MR imaging allowed recognition of the pattern of early reperfu sion. Conclusion. Our preliminary results indicate that dynamic gadoli nium-enhanced subtraction MRI is a simple and promising means of early recognition of ischemia in LCP.