Pneumothorax is a medical emergency caused by the abnormal accumulation of air in the pleural space—the potential space between the lungs and chest wall. On 2D chest radiographs, pneumothorax occurs within the thoracic cavity and outside of the mediastinum, and we refer to this area as “lung + space.” While deep learning (DL) has increasingly been utilized to segment pneumothorax lesions in chest radiographs, many existing DL models employ an end‐to‐end approach. These models directly map chest radiographs to clinician‐annotated lesion areas, often neglecting the vital domain knowledge that pneumothorax is inherently location‐sensitive.
We propose a novel approach that incorporates the lung + space as a constraint during DL model training for pneumothorax segmentation on 2D chest radiographs. To circumvent the need for additional annotations and to prevent potential label leakage on the target task, our method utilizes external datasets and an auxiliary task of lung segmentation. This approach generates a specific constraint of lung + space for each chest radiograph. Furthermore, we have incorporated a discriminator to eliminate unreliable constraints caused by the domain shift between the auxiliary and target datasets.
Our results demonstrated considerable improvements, with average performance gains of 4.6%, 3.6%, and 3.3% regarding intersection over union, dice similarity coefficient, and Hausdorff distance. These results were consistent across six baseline models built on three architectures (U‐Net, LinkNet, or PSPNet) and two backbones (VGG‐11 or MobileOne‐S0). We further conducted an ablation study to evaluate the contribution of each component in the proposed method and undertook several robustness studies on hyper‐parameter selection to validate the stability of our method.
The integration of domain knowledge in DL models for medical applications has often been underemphasized. Our research underscores the significance of incorporating medical domain knowledge about the location‐specific nature of pneumothorax to enhance DL‐based lesion segmentation and further bolster clinicians' trust in DL tools. Beyond pneumothorax, our approach is promising for other thoracic conditions that possess location‐relevant characteristics.
Imran JB, Eastman AL. Pneumothorax. JAMA. 2017;318(10):974. https://doi.org/10.1001/jama.2017.10476
Sahn SA, Heffner JE. Spontaneous pneumothorax. N Engl J Med. 2000;342(12):868–74. https://doi.org/10.1056/NEJM200003233421207
Çallı E, Sogancioglu E, van Ginneken B, van Leeuwen KG, Murphy K. Deep learning for chest X‐ray analysis: a survey. Med Image Anal. 2021;72:102125. https://doi.org/10.1016/j.media.2021.102125
Noppen M, De Keukeleire T. Pneumothorax. Respiration. 2008;76(2):121–7. https://doi.org/10.1159/000135932
Ding W, Shen Y, Yang J, He X, Zhang M. Diagnosis of pneumothorax by radiography and ultrasonography. Chest. 2011;140(4):859–66. https://doi.org/10.1378/chest.10-2946
Gu D, Su K, Zhao H. A case‐based ensemble learning system for explainable breast cancer recurrence prediction. Artif Intell Med. 2020;107:101858. https://doi.org/10.1016/j.artmed.2020.101858
Hong W, Hwang EJ, Lee JH, Park J, Goo JM, Park CM. Deep learning for detecting pneumothorax on chest radiographs after needle biopsy: clinical implementation. Radiology. 2022;303(2):433–41. https://doi.org/10.1148/radiol.211706
Sharma N, Aggarwal L. Automated medical image segmentation techniques. J Med Phys. 2010;35(1):3–14. https://doi.org/10.4103/0971-6203.58777
Duncan JS, Ayache N. Medical image analysis: progress over two decades and the challenges ahead. IEEE Trans Pattern Anal Mach Intell. 2000;22(1):85–106. https://doi.org/10.1109/34.824822
McInerney T, Terzopoulos D. Deformable models in medical image analysis: a survey. Med Image Anal. 1996;1(2):91–108. https://doi.org/10.1016/s1361-8415(96)80007-7
Pham DL, Xu C, Prince JL. Current methods in medical image segmentation. Annu Rev Biomed Eng. 2000;2:315–37. https://doi.org/10.1146/annurev.bioeng.2.1.315
Grau V, Mewes AUJ, Alcaniz M, Kikinis R, Warfield SK. Improved watershed transform for medical image segmentation using prior information. IEEE Trans Med Imaging. 2004;23(4):447–58. https://doi.org/10.1109/TMI.2004.824224
Ahmed MN, Yamany SM, Mohamed N, Farag AA, Moriarty T. A modified fuzzy C‐means algorithm for bias field estimation and segmentation of MRI data. IEEE Trans Med Imaging. 2002;21(3):193–9. https://doi.org/10.1109/42.996338
Xie F, Yuan H, Ning Y, Ong MEH, Feng M, Hsu W, et al. Deep learning for temporal data representation in electronic health records: a systematic review of challenges and methodologies. J Biomed Inf. 2022;126:103980. https://doi.org/10.1016/j.jbi.2021.103980
Wang Q, Liu Q, Luo G, Liu Z, Huang J, Zhou Y, et al. Automated segmentation and diagnosis of pneumothorax on chest X‐rays with fully convolutional multi‐scale ScSE‐DenseNet: a retrospective study. BMC Med Inform Decis Mak. 2020;20(Suppl 14):317. https://doi.org/10.1186/s12911-020-01325-5
Iqbal T, Shaukat A, Akram MU, Mustansar Z, Khan A. Automatic diagnosis of pneumothorax from chest radiographs: a systematic literature review. IEEE Access. 2021;9:145817–39. https://doi.org/10.1109/ACCESS.2021.3122998
McBee MP, Awan OA, Colucci AT, Ghobadi CW, Kadom N, Kansagra AP, et al. Deep learning in radiology. Academic Radiol. 2018;25(11):1472–80. https://doi.org/10.1016/j.acra.2018.02.018
Moses DA. Deep learning applied to automatic disease detection using chest X‐rays. J Med Imaging Radiat Oncol. 2021;65(5):498–517. https://doi.org/10.1111/1754-9485.13273
Tang YX, Tang YB, Peng Y, Yan K, Bagheri M, Redd BA, et al. Automated abnormality classification of chest radiographs using deep convolutional neural networks. npj Digital Med. 2020;3:70. https://doi.org/10.1038/s41746-020-0273-z
Krizhevsky A, Sutskever I, Hinton GE. ImageNet classification with deep convolutional neural networks. Commun ACM. 2017;60(6):84–90. https://doi.org/10.1145/3065386
Thian YL, Ng D, Hallinan JTPD, Jagmohan P, Sia SY, Tan CH, et al. Deep learning systems for pneumothorax detection on chest radiographs: a multicenter external validation study. Radiol: Artif Intell. 2021;3(4):e200190. https://doi.org/10.1148/ryai.2021200190
Wang Y, Sun L, Jin Q. Enhanced diagnosis of pneumothorax with an improved real‐time augmentation for imbalanced chest X‐rays data based on DCNN. IEEE/ACM Trans Comput Biol Bioinf. 2021;18(3):951–62. https://doi.org/10.1109/TCBB.2019.2911947
Feng S, Liu Q, Patel A, Bazai SU, Jin CK, Kim JS, et al. Automated pneumothorax triaging in chest X‐rays in the New Zealand population using deep‐learning algorithms. J Med Imaging Radiat Oncol. 2022;66(8):1035–43. https://doi.org/10.1111/1754-9485.13393
Mosquera C, Diaz FN, Binder F, Rabellino JM, Benitez SE, Beresñak AD, et al. Chest X‐ray automated triage: a semiologic approach designed for clinical implementation, exploiting different types of labels through a combination of four deep learning architectures. Comput Methods Programs Biomed. 2021;206:106130. https://doi.org/10.1016/j.cmpb.2021.106130
Chen KC, Yu HR, Chen WS, Lin WC, Lee YC, Chen HH, et al. Diagnosis of common pulmonary diseases in children by X‐ray images and deep learning. Sci Rep. 2020;10(1):17374. https://doi.org/10.1038/s41598-020-73831-5
Li Y, Wong D, Sreng S, Chung J, Toh A, Yuan H, et al. Effect of childhood atropine treatment on adult choroidal thickness using sequential deep learning‐enabled segmentation. Asia‐Pacific J Ophthalmol. 2024;13(5):100107. https://doi.org/10.1016/j.apjo.2024.100107
Saporta A, Gui X, Agrawal A, Pareek A, Truong SQH, Nguyen CDT, et al. Benchmarking saliency methods for chest X‐ray interpretation. Nat Mach Intell. 2022;4:867–78. https://doi.org/10.1038/s42256-022-00536-x
Agrawal T, Choudhary P. Segmentation and classification on chest radiography: a systematic survey. Visual Comput. 2023;39(3):875–913. https://doi.org/10.1007/s00371-021-02352-7
Wang X, Yang S, Lan J, Fang Y, He J, Wang M, et al. Automatic segmentation of pneumothorax in chest radiographs based on a two‐stage deep learning method. IEEE Trans Cogn Dev Syst. 2022;14(1):205–18. https://doi.org/10.1109/TCDS.2020.3035572
Chen LC, Papandreou G, Kokkinos I, Murphy K, Yuille AL. DeepLab: semantic image segmentation with deep convolutional nets, atrous convolution, and fully connected CRFs. IEEE Trans Pattern Anal Mach Intell. 2018;40(4):834–48. https://doi.org/10.1109/TPAMI.2017.2699184
Tolkachev A, Sirazitdinov I, Kholiavchenko M, Mustafaev T, Ibragimov B. Deep learning for diagnosis and segmentation of pneumothorax: the results on the kaggle competition and validation against radiologists. IEEE J Biomed Health Inform. 2021;25(5):1660–72. https://doi.org/10.1109/JBHI.2020.3023476
Lee SY, Ha S, Jeon MG, Li H, Choi H, Kim HP, et al. Localization‐adjusted diagnostic performance and assistance effect of a computer‐aided detection system for pneumothorax and consolidation. npj Digital Med. 2022;5(1):107. https://doi.org/10.1038/s41746-022-00658-x
Yuan H, Yu K, Xie F, Liu M, Sun S. Automated machine learning with interpretation: a systematic review of methodologies and applications in healthcare. Med Adv. 2024;2(3):205–37. https://doi.org/10.1002/med4.75
Pereira S, Meier R, McKinley R, Wiest R, Alves V, Silva CA, et al. Enhancing interpretability of automatically extracted machine learning features: application to a RBM‐Random Forest system on brain lesion segmentation. Med Image Anal. 2018;44:228–44. https://doi.org/10.1016/j.media.2017.12.009
Yuan H, Kang L, Li Y, Fan Z. Human‐in‐the‐loop machine learning for healthcare: current progress and future opportunities in electronic health records. Med Adv. 2024;2(3):318–22. https://doi.org/10.1002/med4.70
Van Ginneken B, Ter Haar Romeny BM, Viergever MA. Computer‐aided diagnosis in chest radiography: a survey. IEEE Trans Med Imaging. 2001;20(12):1228–41. https://doi.org/10.1109/42.974918
Li F, Armato SG, Engelmann R, Rhines T, Crosby J, Lan L, et al. Anatomic point‐based lung region with zone identification for radiologist annotation and machine learning for chest radiographs. J Digit Imaging. 2021;34(4):922–31. https://doi.org/10.1007/s10278-021-00494-7
Jung HG, Nam WJ, Kim HW, Lee SW. Weakly supervised thoracic disease localization via disease masks. Neurocomputing. 2023;517:34–43. https://doi.org/10.1016/j.neucom.2022.10.019
Bateson M, Dolz J, Kervadec H, Lombaert H, Ayed IB. Constrained domain adaptation for image segmentation. IEEE Trans Med Imaging. 2021;40(7):1875–87. https://doi.org/10.1109/TMI.2021.3067688
Kervadec H, Dolz J, Tang M, Granger E, Boykov Y, Ben Ayed I. Constrained‐CNN losses for weakly supervised segmentation. Med Image Anal. 2019;54:88–99. https://doi.org/10.1016/j.media.2019.02.009
van Ginneken B, Katsuragawa S, ter Haar Romeny BM, Kunio Doi D, Viergever MA. Automatic detection of abnormalities in chest radiographs using local texture analysis. IEEE Trans Med Imaging. 2002;21(2):139–49. https://doi.org/10.1109/42.993132
Shiraishi J, Katsuragawa S, Ikezoe J, Matsumoto T, Kobayashi T, Komatsu K, et al. Development of a digital image database for chest radiographs with and without a lung nodule: receiver operating characteristic analysis of radiologists' detection of pulmonary nodules. AJR Am J Roentgenol. 2000;174(1):71–4. https://doi.org/10.2214/ajr.174.1.1740071
Jaeger S, Candemir S, Antani S, Wáng YX, Lu PX, Thoma G. Two public chest X‐ray datasets for computer‐aided screening of pulmonary diseases. Quant Imaging Med Surg. 2014;4(6):475–7. https://doi.org/10.3978/j.issn.2223-4292.2014.11.20
Huang X, Yang X, Dou H, Huang Y, Zhang L, Liu Z, et al. Test‐time bi‐directional adaptation between image and model for robust segmentation. Comput Methods Programs Biomed. 2023;233:107477. https://doi.org/10.1016/j.cmpb.2023.107477
Larrazabal AJ, Martinez C, Glocker B, Ferrante E. Post‐DAE: anatomically plausible segmentation via post‐processing with denoising autoencoders. IEEE Trans Med Imaging. 2020;39(12):3813–20. https://doi.org/10.1109/TMI.2020.3005297
Souza JC, Bandeira Diniz JO, Ferreira JL, França da Silva GL, Corrêa Silva A, de Paiva AC. An automatic method for lung segmentation and reconstruction in chest X‐ray using deep neural networks. Comput Methods Programs Biomed. 2019;177:285–96. https://doi.org/10.1016/j.cmpb.2019.06.005
Candemir S, Jaeger S, Palaniappan K, Musco JP, Singh RK, Zhiyun Xue X, et al. Lung segmentation in chest radiographs using anatomical atlases with nonrigid registration. IEEE Trans Med Imaging. 2014;33(2):577–90. https://doi.org/10.1109/TMI.2013.2290491
Mansoor A, Bagci U, Xu Z, Foster B, Olivier KN, Elinoff JM, et al. A generic approach to pathological lung segmentation. IEEE Trans Med Imaging. 2014;33(12):2293–310. https://doi.org/10.1109/TMI.2014.2337057
Mansoor A, Cerrolaza JJ, Perez G, Biggs E, Okada K, Nino G, et al. A generic approach to lung field segmentation from chest radiographs using deep space and shape learning. IEEE Trans Biomed Eng. 2020;67(4):1206–20. https://doi.org/10.1109/TBME.2019.2933508
Yuan H, Hong C, Jiang PT, Zhao G, Tran NTA, Xu X, et al. Clinical domain knowledge‐derived template improves post hoc AI explanations in pneumothorax classification. J Biomed Inf. 2024;156:104673. https://doi.org/10.1016/j.jbi.2024.104673
Bateson M, Kervadec H, Dolz J, Lombaert H, Ben Ayed I. Source‐free domain adaptation for image segmentation. Med Image Anal. 2022;82:102617. https://doi.org/10.1016/j.media.2022.102617
Frank O, Schipper N, Vaturi M, Soldati G, Smargiassi A, Inchingolo R, et al. Integrating domain knowledge into deep networks for lung ultrasound with applications to COVID‐19. IEEE Trans Med Imaging. 2022;41(3):571–81. https://doi.org/10.1109/TMI.2021.3117246
Ma J, Chen J, Ng M, Huang R, Li Y, Li C, et al. Loss odyssey in medical image segmentation. Med Image Anal. 2021;71:102035. https://doi.org/10.1016/j.media.2021.102035
Wang L, Wang L, Chen KC, Shi F, Liao S, Li G, et al. Automated segmentation of CBCT image using spiral CT atlases and convex optimization. Med Image Comput Comput Assist Interv. 2013;16(pt 3):251–8. https://doi.org/10.1007/978-3-642-40760-4_32
van Ginneken B, Stegmann MB, Loog M. Segmentation of anatomical structures in chest radiographs using supervised methods: a comparative study on a public database. Med Image Anal. 2006;10(1):19–40. https://doi.org/10.1016/j.media.2005.02.002
Gut D, Tabor Z, Szymkowski M, Rozynek M, Kucybala I, Wojciechowski W. Benchmarking of deep architectures for segmentation of medical images. IEEE Trans Med Imaging. 2022;41(11):3231–41. https://doi.org/10.1109/TMI.2022.3180435
Isensee F, Jaeger PF, Kohl SAA, Petersen J, Maier‐Hein KH. nnU‐Net: a self‐configuring method for deep learning‐based biomedical image segmentation. Nat Methods. 2021;18(2):203–11. https://doi.org/10.1038/s41592-020-01008-z
Cai Z, Vasconcelos N. Cascade R‐CNN: high quality object detection and instance segmentation. IEEE Trans Pattern Anal Mach Intell. 2021;43(5):1483–98. https://doi.org/10.1109/TPAMI.2019.2956516
Foo LL, Lim GYS, Lanca C, Wong CW, Hoang QV, Zhang XJ, et al. Deep learning system to predict the 5‐year risk of high myopia using fundus imaging in children. npj Digital Med. 2023;6(1):10. https://doi.org/10.1038/s41746-023-00752-8
Jaccard P. The distribution of the flora in the alpine zone.1. New Phytol. 1912;11:37–50. https://doi.org/10.1111/J.1469-8137.1912.TB05611.X
Dice LR. Measures of the amount of ecologic association between species. Ecology. 1945;26(3):297–302. https://doi.org/10.2307/1932409
Beauchemin M, Thomson KPB, Edwards G. On the Hausdorff distance used for the evaluation of segmentation results. Can J Remote Sensing. 1998;24(1):3–8. https://doi.org/10.1080/07038992.1998.10874685
Umesh Adiga PS, Chaudhuri BB. An efficient method based on watershed and rule‐based merging for segmentation of 3‐D histo‐pathological images. Pattern Recogn. 2001;34(7):1449–58. https://doi.org/10.1016/s0031-3203(00)00076-5
Wright T, Klein M, Wieczorek J. A primer on visualizations for comparing populations, including the issue of overlapping confidence intervals. Am Stat. 2019;73(2):165–78. https://doi.org/10.1080/00031305.2017.1392359
El Jurdi R, Petitjean C, Honeine P, Cheplygina V, Abdallah F. High‐level prior‐based loss functions for medical image segmentation: a survey. Comput Vis Image Underst. 2021;210:103248. https://doi.org/10.1016/j.cviu.2021.103248
Paul A, Tang YX, Shen TC, Summers RM. Discriminative ensemble learning for few‐shot chest X‐ray diagnosis. Med Image Anal. 2021;68:101911. https://doi.org/10.1016/j.media.2020.101911
Mittal A, Hooda R, Sofat S. Lung field segmentation in chest radiographs: a historical review, current status, and expectations from deep learning. IET Image Processing. 2017;11(11):937–52. https://doi.org/10.1049/iet-ipr.2016.0526
Wang B, Takeda T, Sugimoto K, Zhang J, Wada S, Konishi S, et al. Automatic creation of annotations for chest radiographs based on the positional information extracted from radiographic image reports. Comput Methods Programs Biomed. 2021;209:106331. https://doi.org/10.1016/j.cmpb.2021.106331
Noble JA, Boukerroui D. Ultrasound image segmentation: a survey. IEEE Trans Med Imaging. 2006;25(8):987–1010. https://doi.org/10.1109/tmi.2006.877092
Chen H, Qi X, Yu L, Dou Q, Qin J, Heng PA. DCAN: deep contour‐aware networks for object instance segmentation from histology images. Med Image Anal. 2017;36:135–46. https://doi.org/10.1016/j.media.2016.11.004
Heimann T, Meinzer HP. Statistical shape models for 3D medical image segmentation: a review. Med Image Anal. 2009;13(4):543–63. https://doi.org/10.1016/j.media.2009.05.004
Shamshad F, Khan S, Zamir SW, Khan MH, Hayat M, Khan FS, et al. Transformers in medical imaging: a survey. Med Image Anal. 2023;88:102802. https://doi.org/10.1016/j.media.2023.102802
Lind Plesner L, Müller FC, Brejnebøl MW, Laustrup LC, Rasmussen F, Nielsen OW, et al. Commercially available chest radiograph AI tools for detecting airspace disease, pneumothorax, and pleural effusion. Radiology. 2023;308(3):e231236. https://doi.org/10.1148/radiol.231236
Afrose S, Song W, Nemeroff CB, Lu C, Yao D. Subpopulation‐specific machine learning prognosis for underrepresented patients with double prioritized bias correction. Communications Medicine. 2022;2:111. https://doi.org/10.1038/s43856-022-00165-w
Yuan H. Toward real‐world deployment of machine learning for health care: external validation, continual monitoring, and randomized clinical trials. Health Care Science. 2024;3(5):360–4. https://doi.org/10.1002/hcs2.114
Hu Q, de F Souza LF, Holanda GB, Alves SSA, Dos S Silva FH, Han T, et al. An effective approach for CT lung segmentation using mask region‐based convolutional neural networks. Artif Intell Med. 2020;103:101792. https://doi.org/10.1016/j.artmed.2020.101792
Azizi S, Culp L, Freyberg J, Mustafa B, Baur S, Kornblith S, et al. Robust and data‐efficient generalization of self‐supervised machine learning for diagnostic imaging. Nat Biomed Eng. 2023;7(6):756–79. https://doi.org/10.1038/s41551-023-01049-7
Mao C, Yao L, Luo Y. ImageGCN: multi‐relational image graph convolutional networks for disease identification with chest X‐rays. IEEE Trans Med Imaging. 2022;41(8):1990–2003. https://doi.org/10.1109/TMI.2022.3153322