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ABSTRACT: Apparent diffusion coefficient maps from diffusion-weighted imaging predict gross neurologic outcome in adults with traumatic brain injury. Few studies in children have been reported, and none have used apparent diffusion coefficient maps to predict long-term (>1 year) neurocognitive outcomes. In this study, pooled regional and total brain diffusion coefficients were used to predict long-term outcomes in 17 pediatric brain injury patients. Apparent diffusion coefficient values were grouped into peripheral and deep gray and white matter, posterior fossa, and total brain. Regions of interest excluded areas that appeared abnormal on T(2)-weighted images. Apparent diffusion coefficient values from peripheral regions were inversely correlated with cognitive functioning. No significant correlations were apparent between the cognitive scores and apparent diffusion coefficient values for deep tissue or the posterior fossa. Regression analyses suggested that combined peripheral gray and white matter apparent diffusion coefficients explained 42% of the variance in the combined neurocognitive index. Peripheral gray diffusion coefficients alone explained an additional 20% of variance after accounting for clinical variables. These results suggest that obtaining apparent diffusion coefficient values, specifically from peripheral brain regions, may predict long-term outcome after pediatric brain injury. Discrepancies in the literature on this topic, as well as possible explanations, including sampling and clinical considerations, are discussed.
Pediatric Neurology 12/2009; 41(6):406-12. · 1.52 Impact Factor
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ABSTRACT: Diffusion-weighted imaging (DWI) and consequent apparent diffusion coefficient (ADC) maps have been used for lesion detection and as a predictor of outcome in adults with traumatic brain injury (TBI), but few studies have been reported in children. We evaluated the role of DWI and ADC for outcome prediction after pediatric TBI (n=37 TBI; n=10 controls). Fifteen regions of interest (ROIs) were manually drawn on ADC maps that were grouped for analysis into peripheral gray matter, peripheral white matter, deep gray and white matter, and posterior fossa. All ROIs excluded areas that appeared abnormal on T2-weighted images (T2WI). Acute injury severity was measured using the Glasgow Coma Scale (GCS) score, and 6-12-month outcomes were assessed using the Pediatric Cerebral Performance Category Scale (PCPCS) score. Patients were categorized into five groups: (1) controls; (2) all TBI patients; (3) mild/moderate TBI with good outcomes; (4) severe TBI with good outcomes; and (5) severe TBI with poor outcomes. ADC values in the peripheral white matter were significantly reduced in children with severe TBI with poor outcomes (72.8+/-14.4x10(-3) mm2/sec) compared to those with severe TBI and good outcomes (82.5+/-3.8x10(-3) mm2/sec; p<0.05). We also found that the average total brain ADC value alone had the greatest ability to predict outcome and could correctly predict outcome in 84% of cases. Assessment of DWI and ADC values in pediatric TBI is useful in evaluating injury, particularly in brain regions that appear normal on conventional imaging. Early identification of children at high risk for poor outcome may assist in aggressive clinical management of pediatric TBI patients.
Journal of Neurotrauma 10/2008; 25(10):1153-62. · 3.65 Impact Factor
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ABSTRACT: Magnetic resonance imaging (MRI) is increasingly used in the assessment of the severity and progression of neurotrauma. We evaluated temporal and regional changes after mild fluid percussion (FPI) and controlled cortical impact (CCI) injury using T2-weighted-imaging (T2WI) and diffusion-weighted imaging (DWI) MRI over 7 days. Region of interest analysis of brain areas distant to the injury site (such as the hippocampus, retrosplenial and piriform cortices, and the thalamus) was undertaken. In the hippocampus of CCI animals, we found a slow increase (51%) in apparent diffusion coefficients (ADC) over 72 h, which returned to control values. The hippocampal T2 values in the CCI animals were elevated by 18% over the 7-day time course compared to control, indicative of edema formation. Histological analysis supported the lack of overt cellular loss in most brain regions after mild CCI injury. FPI animals showed a generalized decrease in hippocampal ADC values over the first 72 h, which then returned to sham levels, with decreased T2 values over the same period, which remained depressed at 7 days. Histological assessment of FPI animals revealed numerous shrunken cells in the hippocampus and thalamus, but other regions showed little damage. Increased immunohistochemical staining for microglia and astroglia at 7 days post-injury was greater in FPI animals within the affected brain regions. In summary, traumatic brain injury is less severe in mild CCI than FPI, based on the temporal events assessed with MRI.
Journal of Neurotrauma 08/2007; 24(7):1147-60. · 3.65 Impact Factor
