Increased brain apparent diffusion coefficient in children with neurofibromatosis type 1

PURPOSE: To describe the changes in brain water diffusibility in five anato mic locations in children with neurofibromatosis type 1 (NF 1) compared wit h these changes in control subjects and to describe the water diffusibility changes associated with hyperintense basal ganglia lesions in children wit h NF 1. MATERIALS AND METHODS: Twenty highly related pairs of children consisting o f one child with NF 1 and one unaffected child were examined. Prospective c omparisons of isotropic apparent diffusion coefficient (ADC) values at five anatomic locations were performed, with and without T2-hyperintense: lesio ns included. Retrospective analysis of hyperintense globus pallidus lesions in 16 children and in the paired control subjects also was performed. RESULTS: Significant increases in ADC values were seen in all five anatomic locations in the NF 1 group. The greatest increases were seen in the globu s pallidus (14%; P = .002) and brachium pontis (10.8%; P = .003). With excl usion of hyperintense lesions, significant ADC increases were measured in f our locations. Significant ADC increases were seen in hyperintense globus p allidus lesions in the NF 1 group compared with ADC values in the normal-ap pearing contralateral globus pallidus (4.9%; P = .02) and those in the glob us pallidus of the paired control subjects (16%; P = .003). CONCLUSION: Significant ADC increases were measured both in the hyperintens e lesions and in the normal-appearing areas of the brain in children with N F 1.