Keywords:
Physics, CT, Radiographers, Trauma
Authors:
T. Esaki, T. Kawashima; Shimotsuke City/JP
DOI:
10.26044/ecr2019/C-0129
Methods and materials
CT scanning
A whole-body phantom and two arm phantoms were scanned on a SOMATOM Definition AS+ (eFOV) and Biograph mCT(HD FOV Pro)(Siemens Medical Solutions.
Germany).
The scan parameters were set at 120 kV,
50 mAs,
1.0 s/rotation,
128 × 0.6 mm detector configuration(eFOV),
40 × 0.6 mm detector configuration (HD FOV Pro) and a pitch of 1.0.
Images were reconstructed at B40s kernel,
3mm slice thickness,
and 650mm display FOV.
Using the point where the limbic region around the upper arm of the phantom meets the SFOV boundary as the reference point,
offsets were set at 1 cm intervals to 5 cm outside SFOV (Fig. 3).
Similarly,
the upper arm phantom was wrapped with 30 x 30 x 0.5-cm and 30 x 30 x 1-cm boluses.
analysis
In each algorithm,
CT value and phantom diameter were compared.
For measurement of CT value,
an ROI with a diameter of 1 cm was used at a position 7 cm from the inside of the phantom (Fig. 4).
The phantom diameter was measured in the CT value range from -1000 HU to -1000 HU (Fig. 5).