Keywords:
Diagnostic or prognostic study, Retrospective, Metastases, Cancer, Comparative studies, CT, Radioprotection / Radiation dose, Oncology, Image Quality, Performed at one institution
Authors:
M. Nicolò, M. Di Terlizzi, L. Grazioli; Brescia/IT
DOI:
10.26044/ecr2020/C-10519
Methods and materials
Study design
This is a single-center retrospective study and 30 patients (63 years old ±14) who suffer from tumours were enrolled during their follow-up.
Acquisition protocol
We set the AIDR 3D at its maximum level and we used a low dose protocol (Toshiba Aquilion Prime, Canon Medical System Corporations) with SD (noise amount) set to 15 (Group A), while our standard is 11 (Group B). The kVp were 120 for each phase in each protocol. We compared the Dose Lenght Product (DLP) obtained and the radiation effective dose (ED) with the patient's precedent examination that had a standard level of iterative reconstraction. The radiation effective dose (ED) was calculated by multiplying DLP by an abdominal-specific correction coefficient (0.015).
The patients underwent contrast-enhanced examanitaions (21 thoracoabdominal-pelvic portal phase, 6 thoracoabdominal-pelvic multiphase and 3 abdominalpelvic multiphase).
Image assessment
The image quality was evaluated with an objective and subjective assessment. The first one was performed by a different radiographer with the measurement of the mean HU and noise in the right epatic lobe, portal vein, descending thoracic aorta, abdominal aorta and in the right paravertebral muscle. The second one was a double-blind scoring of axial images carried out by two board-certified radiologists with more than 5 years in CT reporting in terms of overall quality, sharpness, noise and acceptability.
Data analysis
Data were analyzed using paired T test (SOFA, Paton-Simpton & Associates).