Florian Schwarz MD, Presenter: Nothing to Disclose

Matthias Hintz, Abstract Co-Author: Nothing to Disclose

Christopher Uebleis MD, Abstract Co-Author: Nothing to Disclose

Alexander Sterzik, Abstract Co-Author: Nothing to Disclose

Christian Kupatt MD, PhD, Abstract Co-Author: Nothing to Disclose

Maximilian F. Reiser MD, Abstract Co-Author: Nothing to Disclose

Hans-Christoph Richard F. Becker MD, PhD, Abstract Co-Author: Speaker, Bracco Group Speaker, Bayer AG Speaker, Guerbet SA Speaker, Siemens AG Consultant, Amgen Inc

Andreas Pomschar MD, Abstract Co-Author: Nothing to Disclose

Roy Marcus MD, Abstract Co-Author: Nothing to Disclose

Dominik Zinsser BS, Abstract Co-Author: Nothing to Disclose

Vera Sophie Schneider BS, Abstract Co-Author: Nothing to Disclose

To evaluate image quality and radiation dose saving potential of a CT scan protocol that uses a detector with integrated signal-transformation, a high-pitch acquisition technique, automatic kVp selection and an iterative reconstruction algorithm.

Between January and April 2014, 55 consecutive patients underwent CT angiography (CTA) of the chest, abdomen and pelvis on a third-generation dual-source CT using an ultra high-pitch (73 cm/s) acquisition protocol, topogram-based automatic kVp selection and mAs modulation in combination with a model based iterative reconstruction algorithm (group 1). As a control group, 55 patients who had undergone CTA with comparable scan ranges on a second-generation dual-source CT in 2012 and 2013 were matched according to gender, age and BMI (group 2). In all patients, 20 vascular segments were analyzed for attenuation and image noise by two readers on 3.0mm slices. Signal-to-Noise ratio (SNR) and Contrast-to-Noise ratio (CNR) were calculated for all segments. Dose-Length-Product (DLP) was documented to calculate effective dose.

There were no significant differences in age, weight or BMI between groups. In group 1, tube potential was 90kVp, 80kVp and 70kVp in 29 (53%), 24 (43%) and 2 (4%) patients. In group 2, tube potential was 140kVp, 120kVp and 100kVp in 7 (13%), 29 (53%) and 19 (34%) patients. Across all vascular segments, SNR and CNR were considerably higher in group 1 (SNR: 29.6 ± 3.3 vs. 21.0 ± 3.0; CNR: 26.7 ± 3.9 vs. 18.3 ± 2.9, both p’s < 0.01). DLP, on the other hand, was substantially lower in group 1 (230 ± 63 vs. 391 ± 166 cm*mGy, p<0.001).

In third-generation dual-source CT scanners, the combination of an integrated detector design, a high-pitch acquisition technique, automatic kVp selection and iterative-reconstruction algorithms results in dose reductions of at least 40% in comparison with earlier scanner generations at preserved image quality.

This study highlights the importance of a rapid and successful translation of the considerable engineering progress of the last years into radiation dose reduction and thus patient benefit.

Schwarz, F, Hintz, M, Uebleis, C, Sterzik, A, Kupatt, C, Reiser, M, Becker, H, Pomschar, A, Marcus, R, Zinsser, D, Schneider, V, Substantial Radiation Dose Reductions in Wide-Range CT Angiography using an Integrated Detector Design, Ultra High-Pitch Acquisition, Auto-kVp-Selection and Model-based Iterative Reconstruction.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14014832.html