Low-dose vs standard-dose photon-counting CT for myopathy-associated interstitial lung disease: a prospective feasibility study.
Authors
Affiliations (15)
Affiliations (15)
- Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
- State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Beijing, China.
- Department of Rheumatology and Clinical Immunology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College; National Clinical Research Center for Dermatologic and Immunologic Diseases (NCRC-DID), Ministry of Science & Technology; Key Laboratory of Rheumatology and Clinical Immunology, Ministry of Education, Beijing, China.
- Medical Research Center, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
- Department of Medical AI Solutions, Contextflow GmbH, Vienna, Austria.
- Computational Imaging Research Lab, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria.
- Department of Evidence-based Medicine, Xuanwu Hospital, Capital Medical University, Beijing, China.
- Siemens Healthineers Digital Technology (Shanghai) Co. Ltd., Shanghai, China.
- Department of Radiology, The First People's Hospital of Yinchuan, The Second Affiliated Hospital of Ningxia Medical School, Yinchuan, China.
- Department of Radiology, The first Affiliated Hospital of Henan University of Traditional Chinese Medicine, Zhengzhou, China.
- Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China. [email protected].
- State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Beijing, China. [email protected].
- State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Beijing, China. [email protected].
- Department of Rheumatology and Clinical Immunology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College; National Clinical Research Center for Dermatologic and Immunologic Diseases (NCRC-DID), Ministry of Science & Technology; Key Laboratory of Rheumatology and Clinical Immunology, Ministry of Education, Beijing, China. [email protected].
- State Key Laboratory of Common Mechanism Research for Major Diseases, Beijing, China.
Abstract
To evaluate the clinical utility of photon counting computed tomography (PCCT)-derived quantitative parameters for assessing interstitial lung disease (ILD) burden in patients with inflammatory idiopathic myopathy (IIM), comparing standard-dose (SD) and tin-filtered low-dose (LD) protocols, and to assess the added value of ultrathin reconstructions. In this single-centre prospective study (September 2023-November 2024), outpatients with IIM-ILD underwent two consecutive PCCT scans. Quantitative ILD features were extracted using a commercial deep-learning software (ContextFlow ADVANCE Chest CT). Primary analyses compared LD 1.0 mm with SD 1.0 mm reconstructions using Bland-Altman analysis, with exploratory analyses of ultrathin (0.4 mm) reconstructions. Correlation analyses between deep learning-derived quantitative parameters, visual assessment, and pulmonary function tests were performed. Forty-eight adults with IIM-ILD (40 females; mean age, 53.88 ± 11.13 years) were included. The LD protocol achieved a substantial dose reduction (CTDIvol: 0.77 vs 5.40 mGy) while maintaining good agreement with SD (mean net differences [MNDs] < 1% for all patterns). LD-1.0 mm protocol yielded higher volume of ground-glass opacity (MND, 0.98%) and lower volume of fibrosis extent (MND, -0.64%). Reticular pattern showed strong association with FVC% (rho<sub>SD1.0mm</sub> = -0.62, p < 0.001) and DLCO% (rho<sub>SD1.0mm</sub> = -0.73, p < 0.001), with similar correlations observed under LD acquisition (Δrho ≤ 0.02). Ultrathin reconstructions yielded greater measurement of bronchiectasis (MND, 0.13% on SD scans). LD PCCT serves as a radiation-sparing alternative for quantitative disease assessment. Ultrathin reconstructions provide limited additional value. Future longitudinal studies are warranted to validate the performance of LD PCCT for disease monitoring. Question Can LD photon-counting CT provide robust quantitative assessment of ILD burden in patients with inflammatory myopathy compared with SD imaging? Findings Deep learning segmentation yielded LD ILD patterns that closely matched SD results, with all MNDs below 1%. Clinical relevance LD PCCT maintains quantitative robustness and physiological validity for IIM-ILD assessment, with total disease burden showing good agreement with the SD protocol, offering a radiation-sparing alternative without compromising CT-physiology correlation.