OBJECT The object of this study was to use diffusion tensor imaging (DTI) to evaluate and characterize white matter changes in hydrocephalus. METHODS The authors performed a retrospective analysis of DTI in a cohort of patients with hydrocephalus (n = 35), 19 of whom had both pre- and postsurgical imaging studies. These patient's DTI values were compared with values extracted from age-dependent trend lines computed from a healthy subject group (n = 70, age span 14 months-14 years). Several DTI parameters in different regions of interest (ROIs) were evaluated to find the most sensitive parameters for clinical decision making in hydrocephalus. RESULTS Compared with healthy controls, patients with active hydrocephalus had a statistically significant change in all DTI parameters. The most sensitive and specific DTI parameter for predicting hydrocephalus was axial diffusivity (λ1) measured at the level of the corona radiata. Diffusion tensor imaging parameters correlated with several conventional radiological parameters in the assessment of hydrocephalus but were not superior to them. There was no convincing correlation between clinical disease severity and DTI parameters. When examining the pre- and postsurgical effect, it was found that DTI may be a sensitive tool for estimating tissue improvement. CONCLUSIONS This large-cohort study with a multidisciplinary approach combining clinical, neurological, radiological, and multiple DTI parameters revealed the most sensitive DTI parameters for identifying hydrocephalus and suggested that they may serve as an important tool for the disorder's quantitative radiological assessment.
Keywords: CR = corona radiata; CSF = cerebrospinal fluid; DTI = diffusion tensor imaging; ETV = endoscopic third ventriculostomy; FA = fractional anisotropy; GENU = genu of the corpus callosum; HCP group = hydrocephalus group; ICP = intracranial pressure; MD = mean diffusivity; OR = optic radiation; ROI = region of interest; VPS = ventriculoperitoneal shunt; diffusion magnetic resonance imaging; diffusion tensor imaging; endoscopic third ventriculostomy; hydrocephalus; magnetic resonance imaging; λ1 = diffusivity parallel to the fibers; λ3 = diffusivity perpendicular to the fibers.