Optimization of window settings for virtual monoenergetic imaging in dual-energy CT of the liver: A multi-reader evaluation of standard monoenergetic and advanced imaged-based monoenergetic datasets. Issue 4 (April 2016)

• Record Type: Journal Article
• Authors: De Cecco, Carlo N.; Caruso, Damiano; Schoepf, U. Joseph; Wichmann, Julian L.; Ter Louw, Janet R.; Perry, Jonathan D.; Picard, Melissa M.; Schaefer, Amanda R.; Parker, Leland W.; Hardie, Andrew D.
• Is Part Of: European journal of radiology. Volume 85:Issue 4(2016)
• Page Start: 695
• Page End: 699
• Publication Date: 2016-04
• Subjects: VMI virtual monoenergetic imaging -- VMI+ advanced image-based monoenergetic algorithm -- LB120 Standard linearly-blended -- M70 70-keV standard monoenergetic -- M50+ 50-keV advanced image-based virtual monoenergetic; Dual Energy CT -- Monoenergetic -- Liver -- Hepatocellular carcinoma -- Window; Medical radiology -- Periodicals; Radiology -- Periodicals; Radiologie médicale -- Périodiques; Medical radiology; Periodicals; 616.075705
• DOI: 10.1016/j.ejrad.2016.01.007
• Languages: English
• ISSNs: 0720-048X

Abstract

Highlights: M70 and M50+ keV monoenergetic images show higher contrast attenuation than LB120, which may affect window settings. Arterial and portal M50+ optimal liver W/L is significantly higher than LB120. Dedicated M50+ W/L improves liver lesion detection rates compared to LB120 W/L. Abstract: Objectives: To evaluate optimal window settings for display of virtual monoenergetic reconstructions in third-generation dual-source, dual-energy computed tomography (DECT) of the liver. Methods: Twenty-nine subjects were prospectively evaluated with DECT in arterial (AP) and portal venous (PVP) phases. Three reconstructed datasets were calculated: standard linearly-blended (LB120), 70-keV standard virtual monoenergetic (M70), and 50-keV advanced image-based virtual monoenergetic (M50+). Two readers assessed optimal window settings (width and level, W/L), establishing a mean for each reconstruction which was used for a blinded assessment of liver lesions. Results: The optimal W/L for M50+ were significantly higher for both AP (W = 429.3 ± 44.6HU, L = 129.4 ± 9.7HU) and PVP ( W = 376.1 ± 14.2HU, L = 146.6 ± 7.0HU) than for LB120 (AP, W = 215.9 ± 16.9HU, L = 82.3 ± 9.4HU) (PVP, W = 173.4 ± 8.9HU, L = 69.3 ± 6.0HU) and M70 (AP, W = 247.1 ± 22.2HU, L = 72.9 ± 6.8HU) (PVP, W = 232.0 ± 27.9HU, L = 91.6 ± 14.4HU). Use of the optimal window setting for M50+ vs. LB120 resulted in higher sensitivity (AP, 100% vs. 86%; PVP, 96% vs. 63%). Conclusions: Application of dedicated window settings results in improved liver lesion detection rates in advanced image-based virtual monoenergetic DECT when customized for arterial and portal venous phases.