Abdominal Computed Tomography Angiography at 80kV: feasibility study
Abstract
Purpose: preliminary evaluation of different dose reduction algorithms in abdominal Computed Tomography Angiography (CTA) with standard scan protocols at 120kV vs. 80kV.
Materials and Methods: prospective, randomized, crossover study. 60 consecutive patients who underwent CTA of the abdomen (Sensation 64, Siemens; Iomeprol 400 mgl/ml Bracco) for suspected or diagnosed Abdominal Aortic Aneurysm (AAA) were enrolled in the study. A standard 120kV/200mAs scan protocol was acquired in all patients (reference tube current modulated with Automatic Exposure Control). In each patient a second scan with 80kV/300mAs (Group 1; n. 20), 80kV/400mAs (Group 2; n. 20), 80kV/500mAs (Group 3; n. 20) was acquired. We used the same scan/reconstruction parameters with the same amount and kind of contrast medium. The radiation dose, the aortic attenuation values, the noise and the signal/noise ratio (S/N) were evaluated.
Results: the mean dose was 9.7±2.7mSv for 120kV (all patients), 3.6±0.8mSv in Group1 (80kV), 5.0±0.6mSv in Group 2 (80kV) and 5.9±1.2mSv in Group 3 (80kV), respectively. The aortic attenuation was 350±59HU (120kV) vs. 534±100HU (80kV), 12±3.5 (120kV) vs. 8.8±3.6 (80kV) for the whole population. Aortic attenuation and S/N were: 328±40HU (120kV) vs. 494±61HU (80kV), 11±2 (120kV) vs. 7±2 (80kV) in Group1; 353±77HU (120kV) vs. 551±117HU (80kV), 11±2.8HU (120kV) vs. 8.4±2.6 (80kV) in Group 2; 389±55HU (120kV) vs. 598±117HU (80kV), 15±5 (120kV) vs. 12±5 (80kV) in Group 3, respectively (p<0.05).
Conclusion: in abdominal CTA, the 80kV/400mAs scan protocol allows a radiation dose reduction of 50% without a significant reduction of S/N ratio
Downloads
Published
Issue
Section
License
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Transfer of Copyright and Permission to Reproduce Parts of Published Papers.
Authors retain the copyright for their published work. No formal permission will be required to reproduce parts (tables or illustrations) of published papers, provided the source is quoted appropriately and reproduction has no commercial intent. Reproductions with commercial intent will require written permission and payment of royalties.
