Whole-Body CT after Motor Vehicle Crash: No Benefit after High-Energy Impact and with Normal Physical Examination

Background Debate continues about the risks and benefits of systematic whole-body CT when no injury is clinically suspected. Risks of whole-body CT include high radiation exposure and iodine contrast agent, but its effectiveness in reducing mortality in low-risk motor vehicle crashes is unclear. Purpose To assess unsuspected injuries revealed at whole-body CT in patients following motor vehicle crash (MVC) meeting only kinetic elements of the Vittel criteria for the severity of trauma, with no evidence of trunk injury and a Glasgow Coma Scale score of 15. Materials and Methods This retrospective study included all consecutive adult patients who consulted an emergency department of a level 1 trauma center between August 2016 and July 2017 if they underwent whole-body CT for one or more kinetic elements of the Vittel criteria, had a normal examination of the trunk, and had a Glasgow Coma Scale score of 15. Data of the MVC mechanism and physical and biologic examinations were collected, as well as patient treatment data after whole-body CT. Whole-body CT examinations were read by two double-blinded readers to help detect unsuspected injuries. Results Ninety-three patients were included; 72 were men with a mean age of 30.8 years ± 12.0 (standard deviation). Sixty-nine patients were occupants of a car. Seventeen patients were hit by a car while on motorbikes, three while on bicycles, and four as pedestrians. Unsuspected injuries were depicted at 11 whole-body CT examinations: eight lung contusions, one acetabular fracture, one sternal fracture, and one adrenal hematoma. None of these injuries required a specific treatment. One patient with lung contusion of more than 30% of lung volume was followed without requiring further treatment. Conclusion In this population, whole-body CT did not lead to any change in patient treatment. These results suggest whole-body CT should not be systematically performed when no evidence of trunk injury is observed in patients following motor vehicle crash meeting only kinetic elements of Vittel criteria. © RSNA, 2019 See also the editorial by Munera and Durso in this issue

Magnetothermodynamics of BPS baby skyrmions

The magnetothermodynamics of skyrmion type matter described by the gauged BPS baby Skyrme model at zero temperature is investigated. We prove that the BPS property of the model is preserved also for boundary conditions corresponding to an asymptotically constant magnetic field. The BPS bound and the corresponding BPS equations saturating the bound are found. Further, we show that one may introduce pressure in the gauged model by a redefinition of the superpotential. Interestingly, this is related to non-extremal type solutions in the so-called fake supersymmetry method. Finally, we compute the equation of state of magnetized BSP baby skyrmions inserted into an external constant magnetic field $H$ and under external pressure $P$, i.e., $V=V(P,H)$, where $V$ is the "volume" (area) occupied by the skyrmions. We show that the BPS baby skyrmions form a ferromagnetic medium.Comment: Latex, 39 pages, 14 figures. v2: New results and references added, physical interpretation partly change