Related Experiment Video
Updated: Dec 25, 2025
X-ray Dose Reduction through Adaptive Exposure in Fluoroscopic Imaging
Published on: September 11, 2011
Potential of Radiation Dose Reduction by Optimizing Z-Axis Coverage in Coronary Computed Tomography Angiography on a
Elia von Felten1, Michael Messerli, Andreas A Giannopoulos
1From the Department of Nuclear Medicine, Cardiac Imaging, University Hospital Zurich, University Zurich, Zurich, Switzerland.
Objective:
The purpose of this study was to quantify the reduction in radiation dose achievable by using the optimal z-axis coverage in coronary computed tomography (CT) angiography (CCTA) on a latest-generation 256-slice scanner.
Methods:
A total of 408 scans were reviewed that were performed on a wide-range detector scanner allowing up to 16-cm z-axis coverage (adjustable in 2-cm increments). For each CCTA study, we assessed the radiation dose (ie, dose-length product and volume CT dose index) and measured the minimum z-axis coverage necessary to cover the complete cardiac anatomy. We calculated the potential radiation dose savings achievable through reduction of the z-axis coverage to the minimum necessary.
Results:
The majority of the CCTA scans were performed with a z-axis coverage of 16 cm (n = 285, 69.9%), followed by 14 cm (n = 121, 29.7%) and 12 cm (n = 2, 0.5%). In the group that was scanned with a collimation of 16 cm, radiation dose could have been reduced by 12.5% in 55 patients, 25% in 195 patients, and 37.5% in 33 patients when using optimal z-axis coverage for CCTA. In the group that was scanned with a collimation of 14 cm, radiation dose could have been reduced by 14.3% in 90 patients, and 28.6% in 30 patients, whereas in the group that was scanned with a collimation of 12 cm, dose could have been reduced by 16.7% in 2 patients.
Conclusions:
Using correct z-axis coverage in CCTA on a latest-generation 256-slice scanner yields average dose reductions of 22.0% but may be as high as 37.5%.
More Related Videos
11:38Voluntary Breath-hold Technique for Reducing Heart Dose in Left Breast Radiotherapy
Published on: July 3, 2014
09:32Time-Resolved, Dynamic Computed Tomography Angiography for Characterization of Aortic Endoleaks and Treatment Guidance via 2D-3D Fusion-Imaging
Published on: December 9, 2021
Related Concept Videos
01:28Imaging Studies for Cardiovascular System V: CT
01:10Computed Tomography
The technique was invented in the 1970s and is based on the principle that as X-rays pass through the body, they are absorbed or reflected at different levels. In the technique, a patient lies on a motorized platform while a computerized axial tomography (CAT) scanner rotates...
01:25Imaging Studies for Cardiovascular System VI: Calcium -Scoring CT
01:20Imaging Studies for Cardiovascular System III: X-Ray
Definition and Purpose
An X-ray, or radiograph, is a non-invasive method that uses ionizing radiation to take images of internal structures. It is mainly used in cardiac imaging to examine the heart, lungs, and major blood vessels, aiming to identify abnormalities in the heart's size, shape, and position, such as heart failure, congenital defects, and vascular...