Document Type : Original Research

Authors

• Farid Esmaely ¹
• Pardis Moradnejad ²
• Shabnam Boudagh ³
• Seyed Mohammad Zamani-Aliabadi ¹
• Hamid Reza Pasha ^{2, 3}
• Ahmad Bitarafan- Rajabi ^{1, 2}
• Leyla Ansari ^{1, 4}

¹ Department of Medical Physics, School of Medicine, Iran University of Medical Sciences, Tehran, Iran

² Cardiovascular Research Center, Rajaie Cardiovascular Institute, Tehran, Iran

³ Echocardiography Research Center, Rajaie Cardiovascular Institute, Tehran, Iran

⁴ Department of Nulear Medicine, Imam Sajjad Hospital, Yasuj university of medical science, Yasuj, Iran

Abstract

Background: Infective Endocarditis (IE) is a life-threatening condition that requires rapid and accurate diagnosis. Transesophageal Echocardiography (TEE) is the gold standard for detecting valve vegetations; however, its interpretation is highly operator-dependent and particularly challenging in patients with prosthetic valves. Recent advances in artificial intelligence, especially deep learning, offer opportunities to improve diagnostic accuracy and reduce observer variability.
Objective: This study aimed to evaluate the performance of deep learning–based models for detecting vegetations in TEE images to support the diagnostic workflow of IE.
Material and Methods: In this retrospective experimental study, a Faster Region-based Convolutional Neural Network (Faster R-CNN) was implemented to localize valve vegetations in TEE images. Four model configurations were developed using DenseNet121 and ResNet50 backbones, each trained in frozen and fine-tuned modes. All models were pretrained on RadImageNet. The dataset consisted of 1,000 annotated TEE frames acquired from both native and prosthetic heart valves.
Results: The fine-tuned DenseNet121 model achieved the best performance, with a mean Average Precision (mAP) of 0.653 and an Area Under the Curve (AUC) of 0.858. Its frozen version demonstrated lower performance (mAP=0.416, AUC=0.640). The fine-tuned ResNet50 model reached a mAP of 0.593 and an AUC of 0.789, while the frozen ResNet50 showed the lowest performance (mAP=0.403, AUC=0.601). 
Conclusion: Both fine-tuned DenseNet121 and ResNet50 models demonstrated effective localization of valve vegetations in TEE images, with comparable IoU performance. Although DenseNet121 showed superior classification accuracy, the similar localization results highlight the potential of both models as physician-assistive tools for enhancing IE diagnostic workflows.

Highlights

Farid Esmaely (Google Scholar)

Ahmad Bitarafan- Rajabi (Google Scholar)

Keywords

• Infective Endocarditis
• Transesophageal Echocardiography
• Deep Learning
• Faster R-CNN
• Valve Vegetations
• Computer-Assisted Image Interpretation
• Heart Valves