A Novel Artificial Intelligence Based Denoising Method for Ultra-Low Dose CT Used for Lung Cancer Screening

Larisa Gorenstein; Amir Onn; Michael Green; Arnaldo Mayer; Shlomo Segev; Edith Michelle Marom

doi:10.1016/j.acra.2023.02.019

A Novel Artificial Intelligence Based Denoising Method for Ultra-Low Dose CT Used for Lung Cancer Screening

Acad Radiol. 2023 Nov;30(11):2588-2597. doi: 10.1016/j.acra.2023.02.019. Epub 2023 Apr 3.

Authors

Larisa Gorenstein¹, Amir Onn², Michael Green³, Arnaldo Mayer⁴, Shlomo Segev⁵, Edith Michelle Marom⁴

Affiliations

¹ Department of Diagnostic Radiology, Sheba Medical Center, Tel Hashomer, Israel; Diagnostic Radiology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. Electronic address: larisagorenshtein@gmail.com.
² Institute of Pulmonology, Division of Internal Medicine, Sheba Medical Center, Tel Hashomer, Israel.
³ Department of Computer Science, Ben-Gurion University of the Negev.
⁴ Department of Diagnostic Radiology, Sheba Medical Center, Tel Hashomer, Israel; Diagnostic Radiology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
⁵ Institute for Medical Screening, Division of Internal Medicine, Sheba Medical Center, Tel Hashomer, Israel.

PMID: 37019699
DOI: 10.1016/j.acra.2023.02.019

Abstract

Rationale and objectives: To assess ultra-low-dose (ULD) computed tomography as well as a novel artificial intelligence-based reconstruction denoising method for ULD (dULD) in screening for lung cancer.

Materials and methods: This prospective study included 123 patients, 84 (70.6%) men, mean age 62.6 ± 5.35 (55-75), who had a low dose and an ULD scan. A fully convolutional-network, trained using a unique perceptual loss was used for denoising. The network used for the extraction of the perceptual features was trained in an unsupervised manner on the data itself by denoising stacked auto-encoders. The perceptual features were a combination of feature maps taken from different layers of the network, instead of using a single layer for training. Two readers independently reviewed all sets of images.

Results: ULD decreased average radiation-dose by 76% (48%-85%). When comparing negative and actionable Lung-RADS categories, there was no difference between dULD and LD (p = 0.22 RE, p > 0.999 RR) nor between ULD and LD scans (p = 0.75 RE, p > 0.999 RR). ULD negative likelihood ratio (LR) for the readers was 0.033-0.097. dULD performed better with a negative LR of 0.021-0.051. Coronary artery calcifications (CAC) were documented on the dULD scan in 88(74%) and 81(68%) patients, and on the ULD in 74(62.2%) and 77(64.7%) patients. The dULD demonstrated high sensitivity, 93.9%-97.6%, with an accuracy of 91.7%. An almost perfect agreement between readers was noted for CAC scores: for LD (ICC = 0.924), dULD (ICC = 0.903), and for ULD (ICC = 0.817) scans.

Conclusion: A novel AI-based denoising method allows a substantial decrease in radiation dose, without misinterpretation of actionable pulmonary nodules or life-threatening findings such as aortic aneurysms.

Keywords: Artificial Intelligence; Lung cancer screening; Ultra-low dose CT.