Type:
Poster Presentation
Keywords:
Radioprotection / Radiation dose, Cardiac, CT-Angiography, Diagnostic procedure, Radiation effects, Transplantation
Authors:
D. Beitzke1, V. Berger-Kulemann2, V. Schoepf1, S. Unterhumer2, R. Schernthaner1, R. Nolz1, C. Loewe1, F. Wolf1; 1Vienna/AT, 2Wien/AT
Methods and Materials
150 patients in the follow up of cardiac transplant were included in this prospective study.
CCTA was performed using a 128-row dual-source CT scanner (Somatom Definition Flash; Siemens; Germany).
Patients were randomly assigned to one of the three study groups and were scanned using either the conventional retrospective-triggered spiral technique (120 kV/320 mA,
tube current modulation) in group 1,
the prospective ECG-gated sequence technique (120 kV/320 mA,
main padding window 40-70%) in group 2,
or the prospective ECG-gated sequence technique in the systolic phase with automated tube voltage selection (Automated kV,
main padding window 35-45%) in group 3 (Table 1).
The contrast media did not differ between the study group (70-120 ml Iomeron 400,
Bracco,
Austria).
Subjective image quality was rated using a 16 segment coronary artery model and a four-point scale for each segment :
1 = excellent
2 = good
3 = fair
4 = non-diagnostic
Effective dose (ED) was used to compare the differences in radiation dose and was calculated according to the following formula based on the dose-length-product (DLP) provided by the scanner: ED = DLP(mGy*cm)*0.017(mGy*cm-1).