Hongchang Lee

Dr. Hongchang Lee


Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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6 October 2021 in Applied Sciences
Verified
Journal Article
Open access
PDF file
MHMin Hong
Min Hong
Beanbonyka RimBeanbonyka Rim
Beanbonyka Rim
HLHongchang Lee
Hongchang Lee
Hyeonung JangHyeonung Jang
Hyeonung Jang
JOJoonho Oh
Joonho Oh
SCSeong Jun Choi
Seong Jun Choi
In this study, we propose a multi-class classification method by learning lung disease images with Convolutional Neural Network (CNN). As the image data for learning, the U.S. National Institutes of Health (NIH) dataset divided into Normal, Pneumonia, and Pneumothorax and the Cheonan Soonchunhyang University Hospital dataset including Tuberculosis were used. To improve performance, preprocessing was performed with Center Crop while maintaining the aspect ratio of 1:1. As a Noisy Student of EfficientNet B7, fine-tuning learning was performed using the weights learned from ImageNet, and the features of each layer were maximally utilized using the Multi GAP structure. As a result of the experiment, Benchmarks measured with the NIH dataset showed the highest performance among the tested models with an accuracy of 85.32%, and the four-class predictions measured with data from Soonchunhyang University Hospital in Cheonan had an average accuracy of 96.1%, an average sensitivity of 92.2%, an average specificity of 97.4%, and an average inference time of 0.2 s.

23 April 2023 in Diagnostics
Verified
Journal Article
Open access
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JOJoonho Oh
Joonho Oh
CPChanho Park
Chanho Park
HLHongchang Lee
Hongchang Lee
Beanbonyka RimBeanbonyka Rim
Beanbonyka Rim
YKYounggyu Kim
Younggyu Kim
SCSeong Jun Choi
Seong Jun Choi
The deep learning approach has recently attracted much attention for its outstanding performance to assist in clinical diagnostic tasks, notably in computer-aided solutions. Computer-aided solutions are being developed using chest radiography to identify lung diseases. A chest X-ray image is one of the most often utilized diagnostic imaging modalities in computer-aided solutions since it produces non-invasive standard-of-care data. However, the accurate identification of a specific illness in chest X-ray images still poses a challenge due to their high inter-class similarities and low intra-class variant abnormalities, especially given the complex nature of radiographs and the complex anatomy of the chest. In this paper, we proposed a deep-learning-based solution to classify four lung diseases (pneumonia, pneumothorax, tuberculosis, and lung cancer) and healthy lungs using chest X-ray images. In order to achieve a high performance, the EfficientNet B7 model with the pre-trained weights of ImageNet trained by Noisy Student was used as a backbone model, followed by our proposed fine-tuned layers and hyperparameters. Our study achieved an average test accuracy of 97.42%, sensitivity of 95.93%, and specificity of 99.05%. Additionally, our findings were utilized as diagnostic supporting software in OView-AI system (computer-aided application). We conducted 910 clinical trials and achieved an AUC confidence interval (95% CI) of the diagnostic results in the OView-AI system of 97.01%, sensitivity of 95.68%, and specificity of 99.34%.

9 June 2025 in Bioengineering
Verified
Journal Article
Open access
PDF file
Beanbonyka RimBeanbonyka Rim
Beanbonyka Rim
Hyeonung JangHyeonung Jang
Hyeonung Jang
HLHongchang Lee
Hongchang Lee
Wang Su JeonWang Su Jeon
Wang Su Jeon
Early detection of tuberculosis plays a critical role in effective treatment management. Like active tuberculosis, early identification of inactive forms such as latent or healed tuberculosis is essential to prevent future reactivation. In this study, we developed a deep-learning-based binary classification model to distinguish between active and inactive tuberculosis cases. Our model architecture incorporated an EfficientNet backbone with an MLP-Mixer classification head and was fine-tuned on a dataset annotated by Cheonan Soonchunhyang Hospital. To enhance predictive performance, we applied transfer learning using weights pre-trained on the JFT-300M dataset via the Noisy Student training method. Unlike conventional models, our approach achieved competitive results, with an accuracy of 96.3%, a sensitivity of 95.9%, and a specificity of 96.6% on the test set. These promising outcomes suggest that our model could serve as a valuable asset to support clinical decision-making and streamline early screening workflows for latent tuberculosis.

19 December 2025 in Applied Sciences
Verified
Journal Article
Open access
PDF file
Wang Su JeonWang Su Jeon
Wang Su Jeon
Hyeonung JangHyeonung Jang
Hyeonung Jang
HLHongchang Lee
Hongchang Lee
SCSeong Jun Choi
Seong Jun Choi
This study proposes a unified deep-learning framework for the concurrent classification of Chronic Obstructive Pulmonary Disease (COPD) severity and regression of the FEV1/FVC ratio from chest X-ray (CXR) images. We integrated a ConvNeXt-Large backbone with a Slot Attention mechanism to effectively disentangle and refine disease-relevant features for multi-task learning. Evaluation on a clinical dataset demonstrated that the proposed model with a 5-slot configuration achieved superior performance compared to standard CNN and Vision Transformer baselines. On the independent test set, the model attained an Accuracy of 0.9107, Sensitivity of 0.8603, and Specificity of 0.9324 for three-class severity stratification. Simultaneously, it achieved a Mean Absolute Error (MAE) of 8.2649 and a Mean Squared Error (MSE) of 151.4704, and an R2 of 0.7591 for FEV1/FVC ratio estimation. Qualitative analysis using saliency maps also suggested that the slot-based approach contributes to attention patterns that are more constrained to clinically relevant pulmonary structures. These results suggest that our slot-attention-based multi-task model offers a robust solution for automated COPD assessment from standard radiographs.

24 June 2024 in Applied Sciences
Verified
Journal Article
Open access
PDF file
HLHongchang Lee
Hongchang Lee
Hyeonung JangHyeonung Jang
Hyeonung Jang
Wang Su JeonWang Su Jeon
Wang Su Jeon
SCSeong Jun Choi
Seong Jun Choi
In this study, we propose a method of classification for tympanic membrane diseases and regression of pediatric hearing, using a deep learning model of artificial neural networks. Based on the B7 Backbone model of EfficientNet, a state-of-the-art convolutional neural network model, drop connect was applied in the encoder for generalization, and multi-layer perceptron, which is mainly used in the transformer, was applied to the decoder for improved accuracy. For the training data, the open-access tympanic membrane dataset, divided into four classes, was used as the benchmark dataset, and the SCH tympanic membrane dataset with five classes of tympanic membrane diseases and pediatric hearing was also used as the training dataset. In the benchmark using the open-access tympanic membrane dataset, the proposed model showed the highest performance among the five comparative models with an average accuracy of 93.59%, an average sensitivity of 87.19%, and an average specificity of 95.73%. In the experiment trained on the SCH tympanic membrane disease dataset, the average accuracy was 98.28%, the average sensitivity was 89.66%, the average specificity was 98.68%, and the average inference time was 0.2 s. In the experiment trained on the SCH pediatric hearing dataset, the mean absolute error was 6.8678, the mean squared logarithmic error was 0.2887, and the average inference time was 0.2 s.

27 March 2026 in Sensors
Verified
Journal Article
Open access
PDF file
Wang Su JeonWang Su Jeon
Wang Su Jeon
Hyeonung JangHyeonung Jang
Hyeonung Jang
HLHongchang Lee
Hongchang Lee
CPChan Ho Park
Chan Ho Park
JLJiwon Lyu
Jiwon Lyu
SCSeong Jun Choi
Seong Jun Choi
Distinguishing Active from Inactive Tuberculosis (TB) on Chest X-rays presents a clinical challenge due to overlapping radiological signs. This study introduces Vision Mamba CGSM, a deep learning framework integrating a State Space Model (SSM) backbone with a Context-Guided Slot Mixing (CGSM) module. The SSM captures global anatomical context, while the CGSM module isolates subtle pathological features by applying localized spatial attention. We validated the model using a hierarchical diagnostic scheme covering Normal, Pneumonia, Active TB, and Inactive TB. Experimental evaluations demonstrate an accuracy of 92.96% and a Youden Index of 79.55% on the independent test set. In the specific binary classification of Active vs. Inactive TB, the model recorded a specificity of 97.04%, outperforming standard baseline architectures including ResNet152 and ViT-B. Additional validations on external datasets confirm the consistent generalization of the proposed feature extraction mechanism.