Occult lumbosacral dysraphism in children and young adults: Diagnostic performance of fast screening and conventional MR imaging

PURPOSE: To compare fast screening and conventional magnetic resonance (MR) imaging for the detection of occult dysraphic myelodysptasias in children and young adults. MATERIALS AND METHODS: A retrospective case-control study included 101 pati ents (mean age, 4.9 years; range? 1 day to 26 years) suspected of having oc cult lumbosacral dysraphism. Sixty case patients had myelodysplastic lesion s (19 filar lipoma, 14 syringomyelia, 10 intradural lipoma, eight dermal si nus, five diastematomyelia, five lipomyelomeningocele, two caudal regressio n syndrome); 41 control patients had no dysraphic lesions; 17 patients had associated renal anomalies. Two neuroradiologists reviewed MR images from c onventional and fast screening protocols. Diagnostic performance parameters included sensitivity, specificity, and area under the receiver operating c haracteristic curve (A, value). RESULTS: The sensitivity of conventional and fast screening MR studies was 97.1% and 98.5%, respectively; the specificity was 90.9% and 84.8%, respect ively. The A, value was 0.973 for the fast screening and 0.976 for the conv entional MR studies (P =.83). Interobserver agreement was very good for fas t screening images (K = 0.68) and excellent for conventional images (K = 0. 75). For renal anomalies, the AL value was 0.786 and 0.853 for fast screeni ng and conventional MR imaging, respectively (P = .28). CONCLUSION: Conventional three-plane lumbosacral MR imaging in children and young adults suspected of having occult dysraphism provides better diagnos tic information than does fast screening two-plane MR imaging because of it s higher specificity and interobserver agreement.