Automatic tube current modulation for whole-body polytrauma CT with immobilization devices: is there an increase in radiation dose and degradation of image quality?

Thermal insulation does not hamper assessment of injuries in trauma CT scans

PURPOSE

The use of thermal insulations reduces the risk of hypothermia, therefore decreases the risk of death in trauma victims. The aim of the study was to assess whether thermal insulations cause artifacts, which may hinder the diagnosis of injuries, and how the used thermo-systems alter the radiation dose in polytrauma computed tomography.

METHODS

Computed tomography scans were made using the road accident victim body wrapped consecutively with 7 different covers. 14 injury areas were listed and evaluated by 22 radiologists. The radiation dose was measured using a dosimeter placed on the victim in the abdominal area.

RESULTS

No significant artifacts in any of the tested covers were observed. The presence of few minor artifacts did not hinder the assessment of injuries. Certain materials increased (up to 19,1%) and some decreased (up to -30,3%) the absorbed radiation dose.

CONCLUSIONS

Thermal insulation systems tested in this study do not cause significant artifacts hindering assessment of injuries in CT scans. Concern for artifacts and increased radiation dose should not be a reason to remove patients' thermal insulation during performing trauma CT-scanning.

Effect of Thermal Insulation on Image Quality and Radiation Dose in Polytrauma Computed Tomography

PURPOSE

Unintentional drop in body temperature in trauma victims is an independent risk factor for mortality. We aimed to assess the impact of thermal insulation on image quality and radiation dose in polytrauma computed tomography (CT).

METHODS

Thirteen different insulating covers were used to wrap CT phantoms. Images were assessed subjectively at a radiological workstation and analyzed digitally with dedicated software evaluating the noise intensity, spatial resolution, and image homogeneity. The radiation dose was measured using a dosimeter.

RESULTS

Most materials did not cause significant artifacts apart from 2 heating pads. Although the radiation dose was increased by the majority of insulating covers (up to 64.66%), certain covers decreased the absorbed radiation (up to -7.35%).

CONCLUSIONS

The majority of insulating systems do not cause artifacts in CT scans. When using covers with self-heating warmers, removing the heating pad is suggested due to the risk of considerable artifacts appearing. Certain insulating covers may increase or decrease the radiation dose.

Spinal Immobilization in the Trauma Room - a Survey-Based Analysis at German Level I Trauma Centers

BACKGROUND

Spinal immobilization is a standard procedure in daily out-of-hospital emergency care. Homogenous recommendations concerning the immobilization of trauma patients during the first therapy in the emergency department do not exist. The aim of the current study was the analysis of the existing strategies concerning spinal immobilization in German level I trauma centers by an internet-based survey.

MATERIALS AND METHODS

The current study is a survey-based analysis of the current strategies concerning spinal immobilization in all 107 level I trauma centers in Germany. The internet-based survey consists of 6 items asking about immobilization in the emergency department.

RESULTS

The return rate was 47.7%. In 14 (28.6%) level I trauma centers the patients remained immobilized on the immobilization tool used by the professional emergency care providers. In 19 (38.8%) level I trauma centers the patients were transferred to a stretcher with a soft positioning mattress on it. Patient transfer to a spineboard or to a TraumaMattress was performed in 11 (22.4%) and 7 (14.3%) level I trauma centers, respectively. Trauma patients were never transferred to a vacuum mattress. Cervical spine protection was most of the time performed by a cervical collar (n = 48; 98.0%). In general, the survey's participants were mainly satisfied (mean = 84/100) with the current strategy of spinal immobilization. The satisfaction was best if the spineboard is used.

DISCUSSION

Patient positioning during initial emergency therapy in the emergency department of German level I trauma centers is highly heterogenous. Besides complete full body immobilization, also the lack of any immobilization was reported by the survey's participants.

Maintaining immobilisation devices on trauma patients during CT: a feasibility study

BACKGROUND

To reduce the possibility of secondary deterioration of spinal injuries, it is desirable to maintain the spinal immobilisation that is applied in the prehospital setting throughout computed tomography (CT) scanning. A previous study found that metallic components within the inflation valve of the vacuum mattresses caused CT artefacts. The aim of our study was to investigate the effect of vacuum mattresses with plastic valves on CT artefacts, the radiation dose, and noise compared to a trauma transfer board and the spine boards currently used in our trauma system.

METHODS

We scanned an anthropomorphic whole body phantom with different immobilisation devices on a 128-slice CT scanner using the standard polytrauma CT-protocol at our institution. The phantom was scanned without any immobilisation device and with three different vacuum mattresses, two spine boards, and one trauma transfer board. Two radiologists independently assessed the artefacts. Agreement between the two radiologists was measured using the kappa coefficient. The radiation dose and noise were assessed.

RESULTS

One spine board produced major artefacts due to its metal components. One of the vacuum mattresses resulted in artefacts that impaired clinical judgement. Otherwise, the artefacts predominantly did not impede clinical judgement and were mainly subtle. One of the vacuum mattresses resulted in no artefacts that affected clinical judgement. The overall inter-rater agreement was substantial (0.86, kappa 0.77). We did not observe any artefacts due to plastic valves. The mean CT radiation dose was slightly higher for two of the devices in the head series than that for the trauma transfer board, used as the standard in our system. Only marginal differences were noted for the other devices and series. Small differences in image noise were found between the devices.

CONCLUSIONS

Our results indicate that it is feasible to maintain some vacuum mattresses with plastic valves on trauma patients during CT scanning. The tested mattresses did not result in a considerably increased radiation dose or artefacts that hampered clinical judgement. One of the tested vacuum mattresses produced no artefacts that hampered clinical judgement whatsoever.