Effect of x-ray energy on the radiological image quality in propagation-based phase-contrast computed tomography of the breast

Wan, Sarina; Arhatari, Benedicta D.; Nesterets, Yakov I.; Mayo, Sheridan C.; Thompson, Darren; Fox, Jane; Kumar, Beena; Prodanovic, Zdenka; Hausermann, Daniel; Maksimenko, Anton; Hall, Christopher; Dimmock, Matthew; Pavlov, Konstantin M.; Lockie, Darren; Rickard, Mary; Gadomkar, Ziba; Aminzadeh, Alaleh; Vafa, Elham; Peele, Andrew; Quiney, Harry M.; Lewis, Sarah; Gureyev, Timur E.; Brennan, Patrick C.; Taba, Seyedamir Tavakoli

Abstract

Purpose: Breast cancer is the most common cancer in women in developing and developed countries and is responsible for 15% of women’s cancer deaths worldwide. Conventional absorption-based breast imaging techniques lack sufficient contrast for comprehensive diagnosis. Propagation-based phase-contrast computed tomography (PB-CT) is a developing technique that exploits a more contrast-sensitive property of x-rays: x-ray refraction. X-ray absorption, refraction, and contrast-to-noise in the corresponding images depend on the x-ray energy used, for the same/fixed radiation dose. The aim of this paper is to explore the relationship between x-ray energy and radiological image quality in PB-CT imaging.

Approach: Thirty-nine mastectomy samples were scanned at the imaging and medical beamline at the Australian Synchrotron. Samples were scanned at various x-ray energies of 26, 28, 30, 32, 34, and 60 keV using a Hamamatsu Flat Panel detector at the same object-to-detector distance of 6 m and mean glandular dose of 4 mGy. A total of 132 image sets were produced for analysis. Seven observers rated PB-CT images against absorption-based CT (AB-CT) images of the same samples on a five-point scale. A visual grading characteristics (VGC) study was used to determine the difference in image quality.

Results: PB-CT images produced at 28, 30, 32, and 34 keV x-ray energies demonstrated statistically significant higher image quality than reference AB-CT images. The optimum x-ray energy, 30 keV, displayed the largest area under the curve   (  AUCVGC  )   of 0.754 (p  =  0.009). This was followed by 32 keV (AUCVGC  =  0.731, p  ≤  0.001), 34 keV (AUCVGC  =  0.723, p  ≤  0.001), and 28 keV (AUCVGC  =  0.654, p  =  0.015).

Conclusions: An optimum energy range (around 30 keV) in the PB-CT technique allows for higher image quality at a dose comparable to conventional mammographic techniques. This results in improved radiological image quality compared with conventional techniques, which may ultimately lead to higher diagnostic efficacy and a reduction in breast cancer mortalities.

Citation

Wan, S., Arhatari, B. D., Nesterets, Y. I., Mayo, S. C., Thompson, D., Fox, J., …Taba, S. T. (2021). Effect of x-ray energy on the radiological image quality in propagation-based phase-contrast computed tomography of the breast. Journal of Medical Imaging, 8(05), https://doi.org/10.1117/1.jmi.8.5.052108

• Journal Article Type: Article
• Acceptance Date: Jun 28, 2021
• Publication Date: Jul 12, 2021
• Deposit Date: Jun 2, 2023
• Journal: Journal of Medical Imaging
• Publisher: Society of Photo-optical Instrumentation Engineers
• Peer Reviewed: Peer Reviewed
• Volume: 8
• Issue: 05
• DOI: https://doi.org/10.1117/1.jmi.8.5.052108
• Keywords: Radiology, Nuclear Medicine and imaging