Towards enabling better evaluation of emphysema: investigation into a method to reduce the variability of lung CT attenuation values due to patient size and positioning

Haase V, Noo F, Stierstorfer K, McNitt-Gray M (2022)

Publication Type: Conference contribution

Publication year: 2022

Journal

Progress in Biomedical Optics and Imaging - Proceedings of SPIE

Publisher: SPIE

Book Volume: 12031

Conference Proceedings Title: Progress in Biomedical Optics and Imaging - Proceedings of SPIE

Event location: Virtual, Online

ISBN: 9781510649378

DOI: 10.1117/12.2612527

Abstract

Chronic obstructive pulmonary disease (COPD) is a leading cause of patient mortality and morbidity. Measuring the amount of emphysema via a non-contrast CT scan plays a major role in the assessment of COPD and possible treatment options. We are interested in evaluating variability in lung CT attenuation values, which directly impacts emphysema scoring. Our investigations are focused on bias in these values due to patient size and positioning effects, as well as a method to reduce this bias. An anthropomorphic lung phantom was scanned in both centered and off-centered positions. Furthermore, patient size variation was simulated using a home-made fat belt. The obtained projection data was first pre-processed and reconstructed as conventionally done on the scanner, then pre-processed with a proposed correction pipeline that is designed to reduce scatter and beam hardening errors in a patient-specific manner. The images from the scanner show that off-centering the phantom changes the difference in mean value between the left and right lung, from 1.5 to 6.5 HU. Moreover, with the fat belt, the mean value in both lungs increases by more than 13 HU and the inhomogeneity of the lung tissue, measured with the standard deviation, nearly doubles with presence of a strong cupping artifact. Using the proposed method to reduce bias, the mean values of the left and right lung are generally closer to each other, the inhomogeneity is either reduced or unchanged, and the cupping artifact is much less pronounced. This is expected to allow more robust emphysema scoring.

Involved external institutions

University of Utah US United States (USA) (US) University of California Los Angeles (UCLA) US United States (USA) (US)

How to cite

APA:

Haase, V., Noo, F., Stierstorfer, K., & McNitt-Gray, M. (2022). Towards enabling better evaluation of emphysema: investigation into a method to reduce the variability of lung CT attenuation values due to patient size and positioning. In Wei Zhao, Lifeng Yu (Eds.), Progress in Biomedical Optics and Imaging - Proceedings of SPIE. Virtual, Online: SPIE.

MLA:

Haase, Viktor, et al. "Towards enabling better evaluation of emphysema: investigation into a method to reduce the variability of lung CT attenuation values due to patient size and positioning." Proceedings of the Medical Imaging 2022: Physics of Medical Imaging, Virtual, Online Ed. Wei Zhao, Lifeng Yu, SPIE, 2022.

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