Optimal CT protocol for the diagnosis of active bleeding in abdominal trauma patients.

OBJECTIVES: The aim of this study is to compare the radiologic diagnostic performance of arterial phase, portal phase and combined phase computed tomography (CT) for traumatic abdominal injury. In addition, this study is attempted to decrease lifetime attributable risks (LARs) of cancer due to radiation exposure by using optimal CT protocol. MATERIALS AND METHODS: A total of 114 consecutive patients with a traumatic abdominal injury and an abdominal hematoma on CT were enrolled at a single tertiary regional trauma center between January 2016 and March 2017. Each CT protocol set was independently reviewed by three radiologists, and the diagnostic performance of all three CT phases were compared with regard to the capability to detect active bleeding, contained vascular injuries, and organ injuries. Additionally, LARs for cancer incidence and mortality were calculated using dose-length product values, for each phase of CT. RESULTS: The pooled area under the receiver operating characteristic curves for the diagnosis of active bleeding, contained vascular injuries, and organ injuries ranged from 0.910 to 0.922, 0.643 to 0.723, and 0.948 to 0.915 for arterial, portal, and combined phase CT, respectively. There was no statistically significant difference in the diagnosis of active bleeding and organ injuries for any combination of two phase sets. The mean LARs for cancer incidence was 0.059%, 0.062% and 0.121% during arterial, portal and combined phase CT, respectively. CONCLUSION: Single phase CT could be a potential protocol for abdominal trauma patients. Use of single phase CT could significantly decrease the incidence of radiation-associated cancer in the future.

Evaluation of the 2010 American Heart Association Guidelines for infant CPR finger/thumb positions for chest compression: a study using computed tomography.

INTRODUCTION: We sought to verify, using computed tomography (CT) examinations of infants, which the left ventricle (LV) is compressed and abdominal compression avoided by using the chest compression landmarks recommended by the 2010 American Heart Association (AHA) Guidelines for infant cardiopulmonary resuscitation (CPR). METHODS: Using CT examinations of 63 infants performed between March 2002 and July 2011, we retrospectively measured the distance between the INL and the xiphoid process, and the distance of the lower third (LT) of the sternum. The distances between LV maximal diameter (LVMD) and xiphoid processes were also measured to determine whether LVs would be compressed by chest compressions. These distances were compared with the finger placements by 20 adults, when placed on infant mannequins for simulated two-finger or two-thumb infant CPR. RESULTS: The mean distances of the INL and the LT of the sternum were 32 ± 8 mm and 12 ± 2 mm from the xiphoid, respectively. The LVMD was placed 15 ± 6 mm from the xiphoid process. When we overlaid the width of adult finger placement (a mean of 28 mm for two-finger technique, and 23 mm for two-thumb technique), the LV was compressed in 57 patients (90.5%) and 59 patients (93.7%), respectively. The upper abdomen was compressed in 22 patients (34.9%) by the two-finger technique and in 16 patients (25.3%) by the two-thumb technique with the range of 0.3-10.8mm. CONCLUSION: When applying the 2010 AHA Guidelines for infant CPR, recommended finger placement allows for adequate compression of the LV in more than 90% of patients. In 23-35% of infants, the upper abdomen is compressed from 0.3mm to 10.7 mm.