Whole-body CT in polytrauma patients: effect of arm positioning on thoracic and abdominal image quality

Abstract

The purpose of this study is to assess the influence of different arm positioning techniques on thoracic and abdominal image quality and radiation dose of wholebody trauma CT (wbCT). One hundred and fifty polytrauma patients (104 male, mean age 47±19) underwent wbCT with arms elevated above the head (group A, n=50), alongside the abdomen (group B, n=50), and on a pillow ventrally to the chest with both arms flexed (group C, n=50). Two blinded, independent observers measured image noise and rated image quality (scores 1-3) of the liver, aorta, spleen, spine, and lower lungs. Radiation dose parameters were noted, and the abdomens' anterior-posterior diameter and scan lengths were measured. Interreader agreements for image noise (r= 0.86; p<0.001) and subjective image quality (k=0.71-0.84) were good. Noise was lower (p<0.05), image quality of the liver, aorta, spleen, and spine was higher, and radiation dose lower in group A than in groups B and C (p<0.001, each). Image quality of the spleen, liver, and aorta were higher in group C than in group B (p<0.05, each). No significant differences in scan length (p=0.61) were found among groups. Abdominal anterior-posterior diameter correlated significantly with noise (r=0.82; p<0.01) and dose (r=0.47; p<0.001). Estimated effective radiation doses were significantly (p<0.001) higher in groups B (21.2 mSv) and C (21.9 mSv) as compared to A (16.1 mSv). In wbCT for polytrauma patients, positioning of the arms above the head results in better image quality and lower radiation dose. Placing the flexed arms on a large pillow ventrally to the chest significantly improves image quality as compared to positioning alongside the abdomen.

Dose reduction in 64-row whole-body CT in multiple trauma: an optimized CT protocol with iterative image reconstruction on a gemstone-based scintillator

“…26 The scan protocols published have been heterogeneous in terms of scan parameters, which have been adjusted to the institutional needs of image quality and patients' characteristics. However, comparable scan protocols resulted in a drop of the mean effective dose of 21.2-24.69 mSv, 27,28 which is similar to our result of 24.4 mSv with FBP.…”

“…Besides artefacts that can be caused by technical applications, such as electrocardiography cables, the arm positioning influences the image quality. 28 With respect to the factor time, patient's safety and standardization of procedures, the arms were positioned in front of the trunk according to our institutional WBCT protocol for trauma patients.…”

Hyperlordosis is Associated With Facet Joint Pathology at the Lower Lumbar Spine

“…We retrospectively analyzed CT scans of 620 individuals, with a mean age of 42.5 (range, 14-94) years, who presented to our traumatology department and underwent a whole body CT scan, including the pelvis and lumbar spine, between 2008 and 2010. A dualsource computed tomography scanner (Somatom Definition, Siemens Healthcare, Forchheim, Germany) was used [33]. Our study utilized CT scans instead of plain radiographs or MRIs, because they are more accurate in displaying FJs on axial planes [34,35].…”

Quality and Dose Optimized CT Trauma Protocol – Recommendation from a University Level-I Trauma Center

“…Factors that influence these parameters are mostly of a technical nature, such as tube voltage [7], automated exposure control (AEC), the use of iterative reconstruction (IR) [8,9], and different ways to inject contrast agent (CA) [10 -13]. However, nontechnical aspects, such as patient positioning (e. g., placement of arms), play a crucial role in examination optimization [14,15].…”