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Riedy G.,National Capital Neuroimaging Consortium NCNC | Riedy G.,NIC Inc | Riedy G.,Center for Neuroscience and Regenerative Medicine | Riedy G.,Uniformed Services University of the Health Sciences | And 31 more authors.
Radiology | Year: 2016

Purpose: To describe the initial neuroradiology findings in a cohort of military service members with primarily chronic mild traumatic brain injury (TBI) from blast by using an integrated magnetic resonance (MR) imaging protocol. Materials and Methods: This study was approved by the Walter Reed National Military Medical Center institutional review board and is compliant with HIPAA guidelines. All participants were military service members or dependents recruited between August 2009 and August 2014. There were 834 participants with a history of TBI and 42 participants in a control group without TBI (not explicitly age- and sexmatched). MR examinations were performed at 3 T primarily with three-dimensional volume imaging at smaller than 1 mm3 voxels for the structural portion of the examination. The structural portion of this examination, including T1-weighted, T2-weighted, before and after contrast agent administrtion T2 fluid attenuation inversion recovery, and susceptibility-weighted images, was evaluated by neuroradiologists by using a modified version of the neuroradiology TBI common data elements (CDEs). Incident odds ratios (ORs) between the TBI participants and a comparison group without TBI were calculated. Results: The 834 participants were diagnosed with predominantly chronic (mean, 1381 days; median, 888 days after injury) and mild (92% [768 of 834]) TBI. Of these participants, 84.2% (688 of 817) reported one or more blast-related incident and 63.0% (515 of 817) reported loss of consciousness at the time of injury. The presence of white matter T2-weighted hyperintense areas was the most common pathologic finding, observed in 51.8% (432 of 834; OR, 1.75) of TBI participants. Cerebral microhemorrhages were observed in a small percentage of participants (7.2% [60 of 834]; OR, 6.64) and showed increased incidence with TBI severity (P < .001, moderate and severe vs mild). T2-weighted hyperintense areas and microhemorrhages did not collocate by visual inspection. Pituitary abnormalities were identified in a large proportion (29.0% [242 of 834]; OR, 16.8) of TBI participants. Conclusion: Blast-related injury and loss of consciousness is common in military TBI. Structural MR imaging demonstrates a high incidence of white matter T2-weighted hyperintense areas and pituitary abnormalities, with a low incidence of microhemorrhage in the chronic phase. © 2015 RSNA. Source


Liu W.,National Capital Neuroimaging Consortium NCNC | Liu W.,Foundation Medicine | Wang B.,National Capital Neuroimaging Consortium NCNC | Wang B.,Foundation Medicine | And 22 more authors.
NMR in Biomedicine | Year: 2013

Perfusion deficits in patients with mild traumatic brain injury (TBI) from a military population were characterized by dynamic susceptibility contrast perfusion imaging. Relative cerebral blood flow (rCBF) was calculated by a model-independent deconvolution approach from the tracer concentration curves following a bolus injection of gadolinium diethylenetriaminepentaacetate (Gd-DTPA) using both manually and automatically selected arterial input functions (AIFs). Linear regression analysis of the mean values of rCBF from selected regions of interest showed a very good agreement between the two approaches, with a regression coefficient of R=0.88 and a slope of 0.88. The Bland-Altman plot also illustrated the good agreement between the two approaches, with a mean difference of 0.6±12.4mL/100g/min. Voxelwise analysis of rCBF maps from both approaches demonstrated multiple clusters of decreased perfusion (p<0.01) in the cerebellum, cuneus, cingulate and temporal gyrus in the group with mild TBI relative to the controls. MRI perfusion deficits in the cerebellum and anterior cingulate also correlated (p<0.01) with neurocognitive results, including the mean reaction time in the Automated Neuropsychological Assessment Metrics and commission error and detection T-scores in the Continuous Performance Test, as well as neurobehavioral scores in the Post-traumatic Stress Disorder Checklist-Civilian Version. In conclusion, rCBF calculated using AIFs selected from an automated approach demonstrated a good agreement with the corresponding results using manually selected AIFs. Group analysis of patients with mild TBI from a military population demonstrated scattered perfusion deficits, which showed significant correlations with measures of verbal memory, speed of reaction time and self-report of stress symptoms. Published 2013. This article is a U.S. Government work and is in the public domain in the USA. Perfusion deficits in patients with mild traumatic brain injury from a military population were characterized by dynamic susceptibility contrast (DSC) imaging. Relative cerebral blood flow (rCBF) calculated using arterial input functions (AIFs) selected from an automated approach demonstrated good agreement with the results obtained using manually selected AIFs. Preliminary group analysis demonstrated scattered perfusion deficits in the patient group, and the perfusion deficits in the cerebellum and anterior cingulate showed significant correlations with measures of verbal memory, speed of reaction time and self-report of stress symptoms. © Published 2013. Source

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