title: Multi-echo susceptibility-weighted imaging and histology of open-field blast-induced traumatic brain injury in a rat model.
abstract: Blast-induced traumatic brain injury is on the rise, predominantly as a result of the use of improvised explosive devices, resulting in undesirable neuropsychological dysfunctions, as demonstrated in both animals and humans. This study investigated the effect of open-field blast injury on the rat brain using multi-echo, susceptibility-weighted imaging (SWI). Multi-echo SWI provided phase maps with better signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR), making it a sensitive technique for brain injury. Male Sprague-Dawley rats were subjected to a survivable blast of 180 kPa. The visibility of blood vessels of varying sizes improved with multi-echo SWI. Reduced signal intensity from major vessels post-blast indicates increased deoxyhaemoglobin. Relative cerebral blood flow was computed from filtered phase SWI images using inferred changes in oxygen saturation from major blood vessels. Cerebral blood flow decreased significantly at day 3 and day 5 post-blast compared with that pre-blast. This was substantiated by the upregulation of β-amyloid precursor protein (β-APP), a marker of ischaemia, in the neuronal perikaya of the cerebral cortex, as observed by immunofluorescence, and in the cortical tissue by western blot analysis. Our findings indicate the presence of brain ischaemia in post-blast acute phase of injury with possible recovery subsequently. Our results from cerebrovascular imaging, histology and staining provide an insight into the ischaemic state of the brain post-blast and may be useful for prognosis and outcome.
authors.affiliation: Laboratory of Molecular Imaging, Singapore Bioimaging Consortium, Singapore.
authors.forename: Sanjay Kumar
authors.initials: SK
authors.lastname: Verma
authors.affiliation: Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore.|Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: Enci Mary
authors.initials: EM
authors.lastname: Kan
authors.affiliation: Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore.|Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: Jia
authors.initials: J
authors.lastname: Lu
authors.affiliation: Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore.
authors.forename: Kian Chye
authors.initials: KC
authors.lastname: Ng
authors.affiliation: Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: Eng Ang
authors.initials: EA
authors.lastname: Ling
authors.affiliation: Laboratory of Molecular Imaging, Singapore Bioimaging Consortium, Singapore.
authors.forename: Sankar
authors.initials: S
authors.lastname: Seramani
authors.affiliation: Laboratory of Molecular Imaging, Singapore Bioimaging Consortium, Singapore.
authors.forename: Bhanu Prakash
authors.initials: BP
authors.lastname: Kn
authors.affiliation: Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore.
authors.forename: Yong Chiat
authors.initials: YC
authors.lastname: Wong
authors.affiliation: Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore.
authors.forename: Mui Hong
authors.initials: MH
authors.lastname: Tan
authors.affiliation: Laboratory of Molecular Imaging, Singapore Bioimaging Consortium, Singapore.|Clinical Imaging Research Centre, Agency for Science, Technology and Research, Singapore.
authors.forename: S Sendhil
authors.initials: SS
authors.lastname: Velan
mesh_terms: D016564:Amyloid beta-Protein Precursor / Q000032:analysis; D000818:Animals; D001753:Blast Injuries / Q000473:pathology*; D001930:Brain Injuries / Q000473:pathology*; D002560:Cerebrovascular Circulation; D004195:Disease Models, Animal; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D059629:Signal-To-Noise Ratio
chemical_list: D016564:Amyloid beta-Protein Precursor
keywords: blast injury; cerebral blood flow; immunohistochemistry; susceptibility-weighted imaging; traumatic brain injury