Erschienen in:
10.05.2016 | Computed Tomography
Single- and dual-energy CT of the abdomen: comparison of radiation dose and image quality of 2nd and 3rd generation dual-source CT
verfasst von:
Julian L. Wichmann, Andrew D. Hardie, U. Joseph Schoepf, Lloyd M. Felmly, Jonathan D. Perry, Akos Varga-Szemes, Stefanie Mangold, Damiano Caruso, Christian Canstein, Thomas J. Vogl, Carlo N. De Cecco
Erschienen in:
European Radiology
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Ausgabe 2/2017
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Abstract
Objectives
To compare single-energy (SECT) and dual-energy (DECT) abdominal CT examinations in matched patient cohorts regarding differences in radiation dose and image quality performed with second- and third-generation dual-source CT (DSCT).
Methods
We retrospectively analysed 200 patients (100 male, 100 female; mean age 61.2 ± 13.5 years, mean body mass index 27.5 ± 3.8 kg/m2) equally divided into four groups matched by gender and body mass index, who had undergone portal venous phase abdominal CT with second-generation (group A, 120-kV-SECT; group B, 80/140-kV-DECT) and third-generation DSCT (group C, 100-kV-SECT; group D, 90/150-kV-DECT). The radiation dose was normalised for 40-cm scan length. Dose-independent figure-of-merit (FOM) contrast-to-noise ratios (CNRs) were calculated for various organs and vessels. Subjective overall image quality and reader confidence were assessed.
Results
The effective normalised radiation dose was significantly lower (P < 0.001) in groups C (6.2 ± 2.0 mSv) and D (5.3 ± 1.9 mSv, P = 0.103) compared to groups A (8.8 ± 2.3 mSv) and B (9.7 ± 2.4 mSv, P = 0.102). Dose-independent FOM-CNR peaked for liver, kidney, and portal vein measurements (all P ≤ 0.0285) in group D. Subjective image quality and reader confidence were consistently rated as excellent in all groups (all ≥1.53 out of 5).
Conclusions
With both DSCT generations, abdominal DECT can be routinely performed without radiation dose penalty compared to SECT, while third-generation DSCT shows improved dose efficiency.
Key Points
• Dual-source CT (DSCT) allows for single- and dual-energy image acquisition.
• Dual-energy acquisition does not increase the radiation dose in abdominal DSCT.
• Third-generation DSCT shows improved dose efficiency compared to second-generation DSCT.
• Dose-independent figure-of-merit image contrast was highest with third-generation dual-energy DSCT.
• Third-generation DSCT shows improved dose efficiency for SECT and DECT.