Injuries in Fatalities of Dismounted Blast: Identification of Four Mechanisms of Head and Spine Injury.

Blast is the most common injury mechanism in conflicts of this century due to the widespread use of explosives, confirmed by recent conflicts such as in Ukraine. Data from conflicts in the last century such as Northern Ireland, the Falklands, and Vietnam up to the present day show that between 16% and 21% of personnel suffered a traumatic brain injury. Typical features of fatal brain injury to those outside of a vehicle (hereafter referred to as dismounted) due to blast include the presence of hemorrhagic brain injury alongside skull fractures rather than isolated penetrating injuries more typical of traditional ballistic head injuries. The heterogeneity of dismounted blast has meant that analysis from databases is limited and therefore a detailed look at the radiological aspects of injury is needed to understand the mechanism and pathology of dismounted blast brain injury. The aim of this study was to identify the head and spinal injuries in fatalities due to dismounted blast. All UK military fatalities from dismounted blast who suffered a head injury from 2007-2013 in the Iraq and Afghanistan conflicts were identified retrospectively. Postmortem computerized tomography images (CTPMs) were interrogated for injuries to the head, neck, and spine. All injuries were documented and classified using a radiology brain injury classification (BIC) tool. Chi-squared (χ2) and Fisher's exact tests were used to investigate correlations between injuries, along with odds ratios for determining the direction of correlation. The correlations were clustered. There were 71 fatalities from dismounted blast with an associated head injury with a CTPM or initial CT available for analysis. The results showed the heterogeneity of injury from dismounted blast but also some potential identifiable injury constellations. These were: intracranial haemorrhage, intracranial deep haemorrhage, spinal injury, and facial injury. These identified injury patterns can now be investigated to consider injury mechanisms and so develop mitigation strategies or clinical treatments. Level of Evidence: Observational. Study type: cohort observational.

Injuries in Underbody Blast Fatalities: Identification of Five Distinct Mechanisms of Head Injury.

Previous research has shown that injuries to the head and neck were prevalent in 73% of all mounted fatalities of underbody blast. The mechanisms that cause such injuries to the central nervous system (CNS) are not yet known. The aim of this study was to identify the head and spinal injuries in fatalities due to underbody blast (UBB) and then develop hypotheses on the causative mechanisms. All U.K. military fatalities from UBB with an associated head injury that occurred during 2007-2013 in the Iraq and Afghanistan conflicts were identified retrospectively. Computed tomography post-mortems (CTPMs) were interrogated for injuries to the head, neck, and spine. All injuries were documented and classified using a radiology classification. Pearson's chi-square and Fisher's exact tests were used to show a relationship between variables and form a hypothesis for injury mechanisms. There were 50 fatalities from UBB with an associated head injury. Of these, 46 had complete CTPMs available for analysis. Chi-square and Fisher's exact tests showed a relationship between lateral ventricle blood and injuries to the abdomen and thorax. Five partially overlapping injury constellations were identified: 1.multiple-level spinal injury with skull fracture and brainstem injury, 2.peri-mesencephalic hemorrhage, 3.spinal and brainstem injury, 4.parenchymal contusions with injury to C0-C1, and 5.an "eggshell" pattern of fractures from direct impact. These injury constellations can now be used to propose injury mechanisms to develop mitigation strategies or clinical treatments.

A proposed novel traumatic brain injury classification system - an overview and inter-rater reliability validation on behalf of the Society of British Neurological Surgeons.

INTRODUCTION: The measurement of traumatic brain injury (TBI) 'severity' has traditionally been based on the earliest Glasgow Coma Score (GCS) recorded, however, the underlying parenchymal pathology is highly heterogonous. This heterogeneity renders prediction of outcome on an individual patient level inaccurate and makes comparison between patients both in clinical practice and research difficult. The complexity of this heterogeneity has resulted in generic all encompassing 'traumatic brain injury protocols'. Early management and studies of neuro-protectants are often done irrespective of TBI type, yet it may well be that a specific treatment may be beneficial in a subset of TBI pathologies. METHODS: A simple CT-based classification system rating the recognised types of blunt TBI (extradural, subdural, subarachnoid haemorrhage, contusions/intracerebral haematoma and diffuse axonal injury) as mild (1), moderate (2) or severe (3) is proposed. Hypoxic brain injury, a common secondary injury following TBI, is also included. Scores can be combined to reflect concomitant types of TBI and predominant location of injury is also recorded. To assess interrater reliability, 50 patient CT images were assessed by 5 independent clinicians of varying experience. Interrater reliability was calculated using overall agreement through Cronbach's alpha including confidence intervals for intra-class coefficients. RESULTS: Interrater reliability scores showed strong agreement for same score and same injury for TBIs with blood on CT and Cronbach's alpha co-efficient (range 0.87-0.93) demonstrated excellent correlation between raters. Cronbach's alpha was not affected when individual raters were removed. CONCLUSIONS: The proposed simple CT classification system has good inter-rater reliability and hence potentially could enable better individual prognostication and targeted treatments to be compared while also accounting for multiple intracranial injury types. Further studies are proposed and underway.

Diagnostic reference levels in paediatric fluoroscopy: how does a secondary referral centre compare with 2018 European guidelines?

OBJECTIVES: To compare diagnostic reference levels (DRLs) in paediatric fluoroscopy at a secondary referral centre with 2018 European guidelines. Secondly, to compare secondary referral centre DRLs for paediatric fluoroscopy examinations not included in European guidelines with 2010 national UK DRLs. METHODS: Paediatric fluoroscopy studies were grouped by age (groups: 0, 1, 5, 10, 15 years) for examination type and analysed retrospectively, over a period of 14 years. DRLs were compared with European DRLs (micturating cystourethrograms (MCUs)) and 2010 UK national DRLs (contrast swallows and meals). RESULTS: 1,586 studies were performed (49% MCUs; 31% meals; 9% swallows). For all age groups, DRLs for MCUs were lower than European DRLs by up to a factor 58 x (1 year age group: secondary referral centre DRL 12 mGycm2 vs European DRL 700 mGycm2). For contrast swallows and meals, 75th percentile doses were lower than 2010 UK national 25th percentile doses in all age groups. CONCLUSION: Maintaining low doses of ionising radiation is particularly important in paediatrics, and our study has found that it is possible to achieve low paediatric fluoroscopy doses in a secondary referral centre setting. ADVANCES IN KNOWLEDGE: Our data may prove useful to other centres and could contribute towards future European DRLs.