Keywords:
Radioprotection / Radiation dose, Radiographers, Professional issues, CT, Radiation safety, Quality assurance
Authors:
R. M. S. C. Pereira, A. B. Ribeiro, A. I. S. Ferreira, H. Pinto, S. Carvalho, M. Santos; Aveiro/PT
DOI:
10.1594/ecr2018/C-1736
Methods and materials
An exploratory and retrospective study was conducted based on data related to routine head CT studies performed with axial mode and stored in the PACS archives of a medium-sized public health institution in Portugal Central Region.
The sample comprised all adult (aged 18 years or older) patients submitted to routine unenhanced-head CT during a one-week period regardless of clinical indication or associated pathology.
All examinations were performed in a 16-slices CT system.
Demographic anonymized patient data,
scan protocol information and dose report data were collected from PACS accessing DICOM Metadata (more information see Table 1) and also axial scan orientation angles (scan angles) were measured using supraorbitomeatal line (SOML) as reference orientation (0º) as illustrated in Fig. 2 .
A control study was performed with an anthropomorphic phantom,
exposing the phantom to a head CT examination using axial routine protocol,
with different axial scan orientation angles.
Angles between 10 degrees and -30 degrees with a 1-degree interval were performed using supraorbitomeatal line (SOML) as reference line(0º).
Statistical analysis was performed using SPSS® Statistics version 24.0 (IBM®,
San Jose,
California) and assessing mean differences between groups (protocol,
age and genre),
correlations and linear regressions between variables.
Statistical significance was achieved when ρ<0,01.
For linear regression,
statistical significance was achieved when ρ<0,001.