Evaluation of Spatial Resolution of Virtual Monochromatic Imaging In Vitro: Effect of Energy Level and Contrast

Shigeru Suzuki; Rika Fukui; Yuzo Yamamoto; Suguru Nakayama; Mayuka Suzuki; Sadatoshi Kuwahara

doi:10.1097/RCT.0000000000001046

Evaluation of Spatial Resolution of Virtual Monochromatic Imaging In Vitro: Effect of Energy Level and Contrast

J Comput Assist Tomogr. 2021 Jan-Feb;45(1):93-97. doi: 10.1097/RCT.0000000000001046.

Authors

Shigeru Suzuki¹, Rika Fukui¹, Yuzo Yamamoto¹, Suguru Nakayama¹, Mayuka Suzuki², Sadatoshi Kuwahara¹

Affiliations

¹ From the Department of Radiology, Tokyo Women's Medical University Medical Center East.
² Medical Department, School of Medicine, Tokyo Medical University, Tokyo, Japan.

PMID: 32976256
DOI: 10.1097/RCT.0000000000001046

Abstract

Objective: Our aim was to evaluate effects of the energy level and contrast on the spatial resolution of virtual monochromatic imaging (VMI).

Methods: With 2 types of computed tomographic (CT) scanners (Discovery CT750 HD and Revolution CT), we scanned an elliptical cylinder acrylic phantom with 20- or 40-fold dilutions of contrast medium and obtained VMI data sets at 40, 50, 60, and 70 keV. We evaluated the effects of energy levels and contrast on modulation transfer function (MTF) and the effect of energy levels on noise power spectra (NPS).

Results: With both CT scanners, MTF decreased significantly as the energy level decreased. The effect of the dilution of contrast media on MTF varied with CT scanners. With both scanners, NPS curves demonstrate uniform increase in NPS across the entire spatial frequency as the energy levels decreased.

Conclusions: The energy level and contrast can affect the spatial resolution of VMIs.

MeSH terms

Algorithms
Humans
Phantoms, Imaging
Radiation Dosage
Radiographic Image Interpretation, Computer-Assisted / methods*
Radiography, Dual-Energy Scanned Projection / methods*
Tomography, X-Ray Computed