Study Design: The lumbar spine of children an adolescents with suspected spondylolysis was assessed by magneting resonance imaging. Objectives: To evaluate the value of MRI in diagnosis and after nonoperative treatment of incipient spondylolysis in children and adolescents. Summary of Background Data: The diagnosis of incipient spondylolysis in children and adolescents is difficult. Radiographs have a low sensitivity and the use of bone scans, computer tomography and MRI controversial. Methods: The study is prospective. The lumbar spine was assessed by MR imaging in children (n=14, mean age 12.4 years) with unspecific low back pain for more than 3 weeks and normal plain radiographs at presentation. Six of the seven children were involved in moderate to severe sport activities. Incipient spondylolysis was diagnosed when on T1 sequences a hypointense area was found within the pars interarticularis of any lumbar vertebra while on T2 sequences a corresponding hyperintense zone was detected. Brace and activity restriction was recommended. Follow-up MRI studies were performed after treatment at 3 months interval. Results: Seven of 14 patients presented with pars edema (T1 hypointense, T2 hyperintense), six at L5 vertebra, one at L4 and L5 vertebra, respectively. After 3 months healing was demonstrated both clinically and by imaging in six children in another child healing was observed after 6 months. Conclusions: MRI showed promising results in detecting and monitoring the early onset of spondylolysis. In our cases early treatment prevented pars defects
