Matthias Benz MD, Presenter: Nothing to Disclose

Caroline Zahringer, Abstract Co-Author: Nothing to Disclose

Achim Kircher, Abstract Co-Author: Nothing to Disclose

Luigia D'Errico, Abstract Co-Author: Nothing to Disclose

Fides Schwartz, Abstract Co-Author: Nothing to Disclose

Maka N. Kekelidze MD, PhD, Abstract Co-Author: Nothing to Disclose

Andre Euler MD, Abstract Co-Author: Nothing to Disclose

Georg M. Bongartz MD, Abstract Co-Author: Research Grant, Bayer AG Research Grant, Siemens AG

Sebastian Tobias Schindera MD, Abstract Co-Author: Research Grant, Siemens AG Research Grant, Ulrich GmbH & Co KG

To compare the radiation dose and image quality of two dual-energy abdominal CT protocols compared with a single-energy protocol.

75 routine abdomino-pelvic CT examinations were performed on a dual-source CT scanner (Somatom Definition Flash, Siemens). 25 CT scans were performed using the dual-energy protocol recommended by the vendor (tube A, 100 kVp, 230 ref. mAs; tube B, 140 kVp, 178 ref. mAs) (protocol A), 25 CT scans were performed using a dose-optimized dual-energy protocol which was evaluated in a previous phantom study (tube A, 100 kVp, 150 ref. mAs; tube B, 140 kVp, 116 ref. mAs) (protocol B), and 25 CT scans were performed using a single-energy CT protocol (120 ref. kVp, 150 ref. mAs) (protocol C). The radiation dose was assessed with the size-specific dose estimates (SSDE) (Radimetrics, Bayer Healthcare). Objective noise measurements were calculated. Five readers scored each scan according to six subjective image quality parameters: noise, contrast, artifacts, visibility of small structures, sharpness, and overall diagnostic confidence.

The body mass index was not significantly different between group A, B, and C (25.7±4.9, 24.9±3.7, and 27.4±4.9 kg/m2, respectively; p=0.12). The SSDE of protocol A, B, and C measured 14.6, 8.1, and 8.0 mGy, respectively (p<0.001). The objective image noise averaged 4.2±0.8, 5.0±0.8, and 5.6±1.0 for protocol A, B, and C, respectively (p<0.001). The five readers ranked protocol A best in all six subjective image quality parameters (p<0.05). Except for the subjective image noise (2.6±0.4 vs. 2.9±0.5; p=0.009), no significant difference in the other five subjective image quality parameters was observed between the dose-optimized dual-energy protocol (protocol B) and the standard single energy protocol (protocol C).

The default dual-energy abdominal CT protocol can be optimized to achieve a dose-neutral scan in comparison to a single-energy CT scan. The dose neutral dual-energy CT scan results in a similar quantitative and qualitative image quality compared to a standard single-energy CT scan.

By optimizing the default abdominal dual-source protocol, dual-energy CT can be acquired at no extra radiation dose compared with single-energy CT, yielding potential clinical benefits from the dual-energy data set.

Benz, M, Zahringer, C, Kircher, A, D'Errico, L, Schwartz, F, Kekelidze, M, Euler, A, Bongartz, G, Schindera, S, Dose Optimization of a Dual-source, Dual-energy Abdominal CT Protocol in Comparison to a Single-source CT Protocol: Assessment of Radiation Dose, Quantitative and Qualitative Image Analysis  .  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14009139.html