Back to Authors

Bağcı, Ulaş

https://orcid.org/0000-0001-7379-6829

Mayo Clinic

Northwestern University

Citations 9

Uncertainty-Aware Explainable AI for Pancreatic Cysts: Identifying Deep Learning Vulnerabilities and Ensuring Safe Clinical Triage in IPMN Management
Aktas, Halil Ertugrul , Bejar, Andrea Mia, Hong, Ziliang , Hendrix, Rutger , Pan, Hongyi, Keles, Elif, Bol, Fergan , Taktak, Yavuz , Topel, Cagdas, Tur, Yalcin, Zhang, Zheyuan, Chatterjee, Neil , Velichko, Yuri, Schoots, Ivo G, Bruno, Marco J, Huang, Chenchan , Gonda, Tamas, Medetalibeyoglu, Alpay, Kartal, Gulbiz Dagoglu, Erturk, Sukru Mehmet, Zhao, Lili, Bolan, Candice W. , Miller, Frank H, Wallace, Michael B, Keswani, Rajesh N, Bagci, Ulas, Bolan, Candice, Durak, Görkem , Bejar, Andrea Mia, Keleş, Elif , Velichko, Yury , Spampinato, Concetto , Schoots, Ivo G. , Bruno, Marco J. , Gonda, Tamas A. , Erturk, Sukru Mehmet, Miller, Frank H., Wallace, Michael B. , Keswani, Rajesh N. , Bağcı, Ulaş

No container title available | March 22, 2026 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.21203/rs.3.rs-9096790/v1 Get It

Abstract Despite growing interest in AI for pancreatic cyst management, no prior study has systematically investigated how lesion characteristics influence model behavior or provided a comprehensive explainability analysis in IPMN malignancy risk stratification. We present the first multi-center study integrating explainable AI with uncertainty quantification to evaluate how cyst type, size, and location affect deep learning performance in IPMN malignancy prediction. Our retrospective study analyzed 170 IPMNs from seven centers using a radiomics-deep learning fusion model. Cases were stratified by dysplasia grade, IPMN type, size, and location; with model interpretability assessed using SHAP, LIME, Grad-CAM, and uncertainty quantification. Overall accuracy was 67.1%, with model uncertainty lower for correct versus incorrect predictions (0.72 vs 0.78, p < 0.001). On subgroup analysis: Low-Risk lesion accuracy exceeded High-Risk (81.3% vs. 42.9%, p < 0.001), BD accuracy was inversely correlated with cyst size while MD remained stable, and body and whole-pancreas cysts stratified more accurately than tail cysts (77.8%, 76.6% vs. 47.8%). AI models face significant, previously uncharacterized performance drops when evaluating complex high-risk IPMNs. Our study shows that integrating uncertainty quantification can successfully flag unreliable predictions, enabling a selective-prediction framework where clinicians can confidently rely on AI for low-risk, low-uncertainty lesions while deferring high-uncertainty cases to expert review.
Cyst-X: AI-Powered Pancreatic Cancer Risk Prediction from Multicenter MRI in Centralized and Federated Learning
Bağcı, Ulaş , Pan, Hongyi , Keleş, Elif , Seyithanoğlu, Deniz, Zhang, Zheyuan , Aktaş, Halil , Bejar, Andrea , Hong, Ziliang , Taktak, Yavuz , Kartal, Gulbiz, Cebeci, Timurhan , Gonzalez, Maria , Zhao, Lili , Agarunov, Emil, Salanitri, Federica Proietto , Tiwari, Pallavi , Bruno, Marco J. , Huang, Chenchang, Bolan, Candice W. , Gonda, Tamas A. , Miller, Frank, Keswani, Rajesh N. , Zhao, Lili , Bagci, Ulas , Durak, Görkem , Medetalibeyoğlu, Alpay , Ertürk, Şükrü Mehmet , Gonzalez, Maria, Velichko, Yury , Spampinato, Concetto , Tiwari, Pallavi , Xu, Ziyue , Jambawalikar, Sachin , Schoots, Ivo G. , Huang, Chenchang, Wallace, Michael B.

No container title available | December 8, 2025 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.21203/rs.3.rs-7236860/v1 Get It

Abstract Pancreatic cancer, projected to become the second-deadliest malignancy in Western societies by 2030, requires urgent innovations in early detection and risk stratification. Intraductal papillary mucinous neoplasms (IPMNs) represent critical precursor lesions, but current clinical guidelines demonstrate suboptimal accuracy in malignancy prediction, leading to either unnecessary surgeries or missed opportunities for early intervention. In this paper, we present Cyst-X, an artificial intelligence (AI) framework that accurately predicts IPMN malignant transformation using multicenter magnetic resonance imaging (MRI) data. Unlike most previous approaches that rely on computed tomography (CT), our method capitalizes on the superior soft tissue contrast of MRI, allowing for more precise identification of subtle imaging biomarkers. We developed and validated deep learning models on 723 T1-weighted and 738 T2-weighted MRI scans from 764 patients among seven international institutions, demonstrating significantly superior performance (AUC=0.82) compared to current clinical (Kyoto) guidelines (AUC=0.75) and expert radiologists. AI-based imaging features correlate strongly with clinically recognized malignancy markers, providing potential biologically relevant insights. This approach holds promise to significantly refine clinical decision-making, reduce unnecessary surgeries, and better identify high-risk IPMN patients for timely intervention. Our approach integrates a novel pancreas segmentation network with robust classification models that identify subtle imaging biomarkers associated with malignancy risk. Importantly, we demonstrate that these models retain high performance in a privacy-preserving federated learning setting, where institutions collaboratively train AI models without exchanging patient data to address key regulatory and ethical barriers. We publicly release the Cyst-X dataset--the first large-scale, multi-center pancreatic cyst MRI collection--to accelerate research in this field. This study addresses a critical clinical need while establishing technical foundations for privacy-preserving AI in radiology that could transform pancreatic cancer management through earlier intervention and reduced unnecessary procedures. The dataset can be accessed at https://osf.io/74vfs/, and the source code for our deep learning segmentation and classification models is available at https://github.com/NUBagciLab/Cyst-X.
Generative AI and Foundation Models in Radiology: Applications, Opportunities, and Potential Challenges
Tavakoli, Neda , Abad, Zahra Shakeri Hossein , Gowda, Vrushab, Samsel, Konrad , Bedayat, Arash , Ghasemiesfe, Ahmadreza , Bagci, Ulas, Hsiao, Albert , Leiner, Tim , Carr, James , Kim, Daniel , Shakeri, Zahra , Rahsepar, Amir Ali , Kim, Daniel , Leiner, Tim , Gowda, Vrushab , Bağcı, Ulaş

Radiology | November 18, 2025 | Volume: 317 | Issue: 2 | Pages: No page available

10.1148/radiol.242961 Get It

Foundation models can streamline imaging workflows, improve diagnostic accuracy, enable personalized treatment, and, via integrated generative artificial intelligence, create synthetic images to augment scarce real-world data; however, successful adoption requires explainability, trust, and workflow integration.
Multi-center evaluation of radiomics and deep learning to stratify malignancy risk of IPMNs
Bejar, Andrea Mia, Gonzalez, Maria , Hong, Ziliang , Aktas, Halil Ertugrul , Zhang, Zheyuan , Pan, Hongyi, Jozwiak, Zeynep Sue, Bol, Fergan , Zhao, Lili , Kartal, Gulbiz Dagoglu, Agarunov, Emil, Bruno, Marco J. , Huang, Chenchang, Gonda, Tamas A. , Bolan, Candice W. , Keswani, Rajesh N. , Tiwari, Pallavi , Bolan, Candice, Gonzalez, María Jaramillo, Durak, Görkem , Keleş, Elif , Pan, Hongyi , Jozwiak, Zeynep Sue, Chen, Chao , Spampinato, Concetto , Medetalibeyoğlu, Alpay , Ertürk, Şükrü Mehmet , Velichko, Yury , Xu, Ziyue , Jambawalikar, Sachin , Schoots, Ivo G. , Huang, Chenchang, Miller, Frank H. , Wallace, Michael B. , Tiwari, Pallavi , Bağcı, Ulaş

No container title available | May 30, 2025 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.21203/rs.3.rs-6622868/v1 Get It

Abstract Distinguishing high-risk intraductal papillary mucinous neoplasms (IPMNs), pancreatic cysts requiring surgery, from low-risk lesions remains a clinical challenge, often resulting in unnecessary procedures due to limited specificity of current methods. While radiomics and deep learning (DL) have been explored for pancreatic cancer, cyst-level malignancy risk stratification of IPMNs remains untapped. We conducted a multi-institutional study (seven centers, 359 T2W MRI images) to assess the feasibility of AI for predicting IPMN dysplasia grade using cyst-level image features. We developed and compared 2D and 3D radiomics-only, deep learning (DL)-only, and radiomics-DL fusion models, using expert radiologist scoring as a baseline reference. Model performance was evaluated using held-out test data. The radiomics-DL fusion model showed the highest discriminatory ability on the test set (AUC 0.692), outperforming the radiomics-only model (AUC 0.665). Expert accuracy varied widely (37.4%-66.7%). The fusion model integrating deep learning and radiomics features from routine T2W MRI (AUC: 0.692) demonstrates potential for objective, cyst-level risk stratification of IPMNs in a multi-center cohort, outperforming both radiomics-only models and expert radiologists. While performance requires improvement for standalone clinical use, this approach offers a scalable, non-invasive method to potentially improve diagnostic accuracy and reduce unnecessary surgical interventions.
Adaptive Aggregation Weights for Federated Segmentation of Pancreas MRI
Pan, Hongyi , Zhang, Zheyuan , Taktak, Yavuz , Keleş, Elif , Aktas, Halil Ertugrul , Velichko, Yury , Schoots, Ivo G. , Bruno, Marco J. , Keswani, Rajesh N. , Bolan, Candice W. , Gonda, Tamas A. , GORRins, Michael G., Velichko, Yuri S , Durak, Görkem , Medetalibeyoğlu, Alpay , Spampinato, Concetto , Tiwari, Pallavi , Wallace, Michael B. , Xu, Ziyue , Bağcı, Ulaş

2025 IEEE 22nd International Symposium on Biomedical Imaging (ISBI) | May 12, 2025 | Volume: No volume available | Issue: No issue available | Pages: 1-5

10.1109/isbi60581.2025.10981148 Get It

IPMN Risk Assessment Under Federated Learning Paradigm
Pan, Hongyi , Hong, Ziliang , Keleş, Elif , Aktas, Halil Ertugrul , Taktak, Yavuz , Medetalibeyoğlu, Alpay , Zhang, Zheyuan , Velichko, Yury , Schoots, Ivo G. , Bruno, Marco J. , Tiwari, Pallavi , Bolan, Candice W. , Gonda, Tamas A. , Miller, Frank, Keswani, Rajesh N. , Miller, Frank H. , Miller, Frank H , Velichko, Yuri S , Durak, Görkem , Spampinato, Concetto , Tiwari, Pallavi , Wallace, Michael B. , Xu, Ziyue , Bağcı, Ulaş

2025 IEEE 22nd International Symposium on Biomedical Imaging (ISBI) | May 12, 2025 | Volume: No volume available | Issue: No issue available | Pages: 1-5

10.1109/isbi60581.2025.10980733 Get It

Advances for Managing Pancreatic Cystic Lesions: Integrating Imaging and AI Innovations
Seyithanoglu, Deniz , Durak, Görkem , Keleş, Elif , Medetalibeyoğlu, Alpay , Hong, Ziliang , Zhang, Zheyuan , Taktak, Yavuz , Cebeci, Timurhan , Tiwari, Pallavi , Velichko, Yury , Yazıcı, Cemal , Tirkes, Temel , Miller, Frank H. , Keswani, Rajesh N. , Wallace, Michael B. , Bağcı, Ulaş , Velichko, Yuri S , Wallace, Michael B , Bagci, Ulas , Miller, Frank H , Tiwari, Pallavi , Spampinato, Concetto

Cancers | December 23, 2024 | Volume: 16 | Issue: 24 | Pages: 4268

10.3390/cancers16244268 Get It

Pancreatic cystic lesions (PCLs) represent a spectrum of non-neoplasms and neoplasms with varying malignant potential, posing significant challenges in diagnosis and management. While some PCLs are precursors to pancreatic cancer, others remain benign, necessitating accurate differentiation for optimal patient care. Conventional approaches to PCL management rely heavily on radiographic imaging, and endoscopic ultrasound (EUS) guided fine-needle aspiration (FNA), coupled with clinical and biochemical data. However, the observer-dependent nature of image interpretation and the complex morphology of PCLs can lead to diagnostic uncertainty and variability in patient management strategies. This review critically evaluates current PCL diagnosis and surveillance practices, showing features of the different lesions and highlighting the potential limitations of conventional methods. We then explore the potential of artificial intelligence (AI) to transform PCL management. AI-driven strategies, including deep learning algorithms for automated pancreas and lesion segmentation, and radiomics for analyzing heterogeneity, can improve diagnostic accuracy and risk stratification. These advanced techniques can provide more objective and reproducible assessments, aiding clinicians in decision-making regarding follow-up intervals and surgical interventions. Early results suggest that AI-driven methods can significantly improve patient outcomes by enabling earlier detection of high-risk lesions and reducing unnecessary procedures for benign cysts. Finally, this review emphasizes that AI-driven approaches could potentially reshape the landscape of PCL management, ultimately leading to improved pancreatic cancer prevention.
Neural Transformers for Intraductal Papillary Mucosal Neoplasms (IPMN) Classification in MRI images
Salanitri, Federica Proietto , Bellitto, Giovanni , Irmakci, Ismail , Wallace, Michael B. , Bolan, Candice W. , Engels, Megan , Hoogenboom, Sanne, Wallace, Michael B , Palazzo, Simone , Aldinucci, Marco , Bağcı, Ulaş , Giordano, D., Spampinato, Concetto

2022 44th Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC) | September 8, 2022 | Volume: No volume available | Issue: No issue available | Pages: 475-479

10.1109/embc48229.2022.9871547 Get It

Deep Learning to Classify Intraductal Papillary Mucinous Neoplasms Using Magnetic Resonance Imaging
Hussein, Sarfaraz , Kandel, Pujan , Bolan, Candice W. , Bağcı, Ulaş , Wallace, Michael B. , Wallace, Michael B , Bagci, Ulas , Corral, Juan E.

Pancreas | June 7, 2019 | Volume: 48 | Issue: 6 | Pages: 805-810

10.1097/mpa.0000000000001327 Get It

Objective This study aimed to evaluate a deep learning protocol to identify neoplasia in intraductal papillary mucinous neoplasia (IPMN) in comparison to current radiographic criteria. Methods A computer-aided framework was designed using convolutional neural networks to classify IPMN. The protocol was applied to magnetic resonance images of the pancreas. Features of IPMN were classified according to American Gastroenterology Association guidelines, Fukuoka guidelines, and the new deep learning protocol. Sensitivity and specificity were calculated using surgically resected cystic lesions or healthy controls. Results Of 139 cases, 58 (42%) were male; mean (standard deviation) age was 65.3 (11.9) years. Twenty-two percent had normal pancreas; 34%, low-grade dysplasia; 14%, high-grade dysplasia; and 29%, adenocarcinoma. The deep learning protocol sensitivity and specificity to detect dysplasia were 92% and 52%, respectively. Sensitivity and specificity to identify high-grade dysplasia or cancer were 75% and 78%, respectively. Diagnostic performance was similar to radiologic criteria. Areas under the receiver operating curves (95% confidence interval) were 0.76 (0.70–0.84) for American Gastroenterology Association, 0.77 (0.70–0.85) for Fukuoka, and 0.78 (0.71–0.85) for the deep learning protocol ( P = 0.90). Conclusions The deep learning protocol showed accuracy comparable to current radiographic criteria. Computer-aided frameworks could be implemented as aids for radiologists to identify high-risk IPMN.