Dose effects and image quality: is there any influence by bearing devices in whole-body computed tomography in trauma patients?

BACKGROUND: Stable bearing devices are often utilized by prehospital first responders in modern management of severely injured patients. It is not known whether these devices influence radiation exposure or image quality in whole-body computed tomography (WBCT). Additionally, manufacturers currently provide no specifications concerning these criteria. This investigation analyzed the influence of nine different bearing devices on these specified criteria. METHODS: The influence of nine different bearing devices on radiation exposure and image quality in WBCT was investigated. The dose-length-product (DLP100) was obtained through use of a CT-ionisation chamber placed in the centre of a 32 cm CT-phantom and compared with a reference value. Moreover, the results were calculated as effective dose data E (mSv). The image quality was assessed by three expert radiologists using the following scoring scale (0=no artefacts; 1=minor artefacts; 2=clearly artefacts; 3=massive artefacts). RESULTS: Out of nine bearing devices examined, four showed significantly higher (2.5-4.5%, p<0.05) DLP100 and five showed no significant difference between DLP100 and the reference value. The image quality was classified in the categories "0", "1", "2" and "3" in 4, 3, 1 and 1 case, respectively. CONCLUSIONS: In diagnostic producers using WBCT, bearing devices may be associated with relevant increases in radiation dose and can affect the image assessability. Some bearing devices are associated with no significant influence on radiation dose and reduction of image quality. Considering all results to get the best balance between image quality and radiation dose, aluminium and metal-free devices should be preferred.

Radiation exposure in whole-body computed tomography of multiple trauma patients: bearing devices and patient positioning.

BACKGROUND: Whole-body computed tomography (WBCT) plays an important role in the management of severely injured patients. We evaluated the radiation exposure of WBCT scans using different positioning boards and arm positions. METHODS: In this retrospective study, the radiation exposure of WBCT using a 16-slice multislice computed tomography scanner was evaluated. Individual effective doses (E, mSV) was calculated. Patients were assigned to two groups according to placement on a plastic transfer mat (PTM, group 1) or on the Trauma Transfer™-Board (TTB, group 2). Data were collected for each group with arm placement on the abdomen (a) or in raising position (b), respectively. The maximum ventro-dorsal diameter [VDD] at the trunk was measured. RESULTS: 100 patients with potentially life-threatening injuries were analysed. Patient demographics and VDD did not differ in the two groups. Radiation exposure in term of E did not reveal any significant differences between the two positioning boards using same arm position [group 1a (n=26) vs. 2a (n=24) (mSV): 16.7±4.7 vs. 17.1±4.4, group 1b (n=26) vs. 2b (n=24) (mSV): 13.1±3.9 vs. 14.3±1.5]. The arm raising positioning showed a significant reduction in E in comparison to the placement on abdomen position [group 1b vs. 1a (mSV): 13.1±3.9 vs. 16.7±4.7, p<0.05, group 2b vs. 2a (mSV): 14.3±1.5 vs. 17.1±4.4, p<0.05]. CONCLUSIONS: Patient arm positioning for WBCT has an important influence on radiation exposure. Effective dose was 16-22% lower when arms were raised. An individual placement algorithm may lead to a relevant reduction of radiation exposure of severely injured patients.