Diagnostic validation of a deep learning nodule detection algorithm in low-dose chest CT: determination of optimized dose thresholds in a virtual screening scenario

• Published in: European radiology Vol. 32; no. 6; pp. 4324 - 4332
• Main Authors: Peters, Alan A., Huber, Adrian T., Obmann, Verena C., Heverhagen, Johannes T., Christe, Andreas, Ebner, Lukas
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.06.2022; Springer Nature B.V
• Subjects: Algorithms; Artificial intelligence; CAI; Chest; Composition; Computer assisted instruction; Deep Learning; Density; Diagnostic Radiology; Dosage; Electric potential; Humans; Imaging; Internal Medicine; Interventional Radiology; Lung cancer; Lung Neoplasms - diagnostic imaging; Machine learning; Medical diagnosis; Medicine; Medicine & Public Health; Neuroradiology; Nodules; Radiation Dosage; Radiographic Image Interpretation, Computer-Assisted - methods; Radiology; Screening; Sensitivity and Specificity; Software; Solitary Pulmonary Nodule - diagnostic imaging; Tomography, X-Ray Computed - methods; Ultrasound; Voltage; Deep learning; Radiographic phantoms; Computer-assisted diagnosis; Artificial intelligence; Lung neoplasms
• ISSN: 1432-1084; 0938-7994; 1432-1084
• DOI: 10.1007/s00330-021-08511-7

Objectives This study was conducted to evaluate the effect of dose reduction on the performance of a deep learning (DL)–based computer-aided diagnosis (CAD) system regarding pulmonary nodule detection in a virtual screening scenario. Methods Sixty-eight anthropomorphic chest phantoms were equipped with 329 nodules (150 ground glass, 179 solid) with four sizes (5 mm, 8 mm, 10 mm, 12 mm) and scanned with nine tube voltage/current combinations. The examinations were analyzed by a commercially available DL-based CAD system. The results were compared by a comparison of proportions. Logistic regression was performed to evaluate the impact of tube voltage, tube current, nodule size, nodule density, and nodule location. Results The combination with the lowest effective dose ( E ) and unimpaired detection rate was 80 kV/50 mAs (sensitivity: 97.9%, mean false-positive rate (FPR): 1.9, mean CTDIvol: 1.2 ± 0.4 mGy, mean E : 0.66 mSv). Logistic regression revealed that tube voltage and current had the greatest impact on the detection rate, while nodule size and density had no significant influence. Conclusions The optimal tube voltage/current combination proposed in this study (80 kV/50 mAs) is comparable to the proposed combinations in similar studies, which mostly dealt with conventional CAD software. Modification of tube voltage and tube current has a significant impact on the performance of DL-based CAD software in pulmonary nodule detection regardless of their size and composition. Key Points • Modification of tube voltage and tube current has a significant impact on the performance of deep learning–based CAD software. • Nodule size and composition have no significant impact on the software’s performance. • The optimal tube voltage/current combination for the examined software is 80 kV/50 mAs.