Keywords:
Cardiac, Cardiovascular system, Radiation physics, CT, CT-Angiography, Dosimetry, Radiation safety, Technical aspects
Authors:
F. Nensa, M. Reinboldt, L. Hemsing, O. H. W. Bruder, K. Nassenstein, T. Schlosser; Essen/DE
DOI:
10.1594/ecr2013/C-0876
Results
Mean ED for CTCA was 10.57±2.76 mSv on the SSCT scanner,
6.96±3.59 mSv on the DSCT standard scanner compared to 1.19±0.66 mSv on the Flash scanner (SSCT vs.
DSCT t-Test: p<0.001,
DSCT vs.
Flash t-Test p<0.001).
Compared to SSCT,
mean dose reduction with Flash was >88% (>82% compared to DSCT).
72% (66/92) of all examinations on the Flash scanner had an ED < 1 mSv.
Using mutivariate regression analysis the acquistion mode (Flash-Helix vs.
Gated-Helix; -6.48 mSv; p<0.001),
the body mass index (BMI; 0.24 mSv per kg/m2 increase; p<0.001) and the total scan length along the longitudinal axis of the patients (0.41 mSv per cm increase; p<0.001) were identified as unique predictors of estimated dose.
In a subgroup of Gated-Helix acquisitions also the Hounsfield units (HU) measured with a region of interest in the lumen of the thoracic aorta were negatively correlated with estimated dose (R=-0.38; p<0.001).
Regardless of the scanner,
image quality was rated as diagnostic in all CTCAs.
However,
the average image quality was rated best on the Flash scanner.