January 2025
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6 Reads
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January 2025
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6 Reads
December 2024
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9 Reads
November 2024
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25 Reads
Spatial transcriptomics (ST) provides essential spatial context by mapping gene expression within tissue, enabling detailed study of cellular heterogeneity and tissue organization. However, aligning ST data with histology images poses challenges due to inherent spatial distortions and modality-specific variations. Existing methods largely rely on direct alignment, which often fails to capture complex cross-modal relationships. To address these limitations, we propose a novel framework that aligns gene and image features using a ranking-based alignment loss, preserving relative similarity across modalities and enabling robust multi-scale alignment. To further enhance the alignment's stability, we employ self-supervised knowledge distillation with a teacher-student network architecture, effectively mitigating disruptions from high dimensionality, sparsity, and noise in gene expression data. Extensive experiments on gene expression prediction and survival analysis demonstrate our framework's effectiveness, showing improved alignment and predictive performance over existing methods and establishing a robust tool for gene-guided image representation learning in digital pathology.
September 2024
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23 Reads
Objective This project demonstrates the feasibility of connecting medical imaging data and features, SARS‐CoV‐2 genome variants, with clinical data in the National Clinical Cohort Collaborative (N3C) repository to accelerate integrative research on detection, diagnosis, and treatment of COVID‐19‐related morbidities. The N3C curated a rich collection of aggregated and de‐identified electronic health records (EHR) data of over 18 million patients, including 7.5 million COVID‐positive patients, seen at hospitals across the United States. Medical imaging data and variant samples are important data modalities used in the study of COVID‐19. Materials and Methods Imaging data and features are hosted on the Cancer Imaging Archive (TCIA), and sequenced variant samples are analyzed and stored at the NIH GenBank. The University of Arkansas for Medical Sciences (UAMS) published the first COVID‐19 data set of 105 patients on TCIA and 37 patients on GenBank. We developed a process to link imaging and genomic variants and N3C EHR data through Privacy Preserving Record Linkage (PPRL) using de‐identified cryptographic hashes to match records associated with the same individuals without using patient identifiers. Results The PPRL techniques were piloted using clinical and imaging data sets provided by UAMS. Developed software components and processes executed properly, and linked data were returned and processed for visualization. Conclusion Linking across clinical data sources at the patient level provides opportunities to gain insights from data that may not be known otherwise. The PPRL prototype and the pilot serve as a model to link disparate and diverse data repositories to enhance clinical research.
September 2024
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52 Reads
IEEE Open Journal of Engineering in Medicine and Biology
In the medical diagnostics domain, pathology and histology are pivotal for the precise identification of diseases. Digital histopathology, enhanced by automation, facilitates the efficient analysis of massive amount of biopsy images produced on a daily basis, streamlining the evaluation process. This study focuses in Stain Color Normalization (SCN) within a Whole-Slide Image (WSI) cohort, aiming to reduce batch biases. Building on published graphical method, this research demonstrates a mathematical population or data-driven method that optimizes the dependency on the number of reference WSIs and corresponding aggregate sums, thereby increasing SCN process efficiency. This method expedites the analysis of color convergence 50- fold by using stain vector Euclidean distance analysis, slashing the requirement for reference WSIs by more than half. The approach is validated through a tripartite methodology: 1) Stain vector euclidean distances analysis, 2) Distance computation timing, and 3) Qualitative and quantitative assessments of SCN across cancer tumors regions of interest. The results validate the performance of data-driven SCN method, thus potential to enhance the precision and reliability of computational pathology analyses. This advancement is poised to enhance diagnostic processes, therapeutic strategies, and patient prognosis.
June 2024
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5 Reads
May 2024
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49 Reads
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3 Citations
Journal of Translational Medicine
Background The immune microenvironment impacts tumor growth, invasion, metastasis, and patient survival and may provide opportunities for therapeutic intervention in pancreatic ductal adenocarcinoma (PDAC). Although never studied as a potential modulator of the immune response in most cancers, Keratin 17 (K17), a biomarker of the most aggressive (basal) molecular subtype of PDAC, is intimately involved in the histogenesis of the immune response in psoriasis, basal cell carcinoma, and cervical squamous cell carcinoma. Thus, we hypothesized that K17 expression could also impact the immune cell response in PDAC, and that uncovering this relationship could provide insight to guide the development of immunotherapeutic opportunities to extend patient survival. Methods Multiplex immunohistochemistry (mIHC) and automated image analysis based on novel computational imaging technology were used to decipher the abundance and spatial distribution of T cells, macrophages, and tumor cells, relative to K17 expression in 235 PDACs. Results K17 expression had profound effects on the exclusion of intratumoral CD8+ T cells and was also associated with decreased numbers of peritumoral CD8+ T cells, CD16+ macrophages, and CD163+ macrophages (p < 0.0001). The differences in the intratumor and peritumoral CD8+ T cell abundance were not impacted by neoadjuvant therapy, tumor stage, grade, lymph node status, histologic subtype, nor KRAS, p53, SMAD4, or CDKN2A mutations. Conclusions Thus, K17 expression correlates with major differences in the immune microenvironment that are independent of any tested clinicopathologic or tumor intrinsic variables, suggesting that targeting K17-mediated immune effects on the immune system could restore the innate immunologic response to PDAC and might provide novel opportunities to restore immunotherapeutic approaches for this most deadly form of cancer.
February 2024
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245 Reads
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239 Citations
Nature Methods
Increasing evidence shows that flaws in machine learning (ML) algorithm validation are an underestimated global problem. In biomedical image analysis, chosen performance metrics often do not reflect the domain interest, and thus fail to adequately measure scientific progress and hinder translation of ML techniques into practice. To overcome this, we created Metrics Reloaded, a comprehensive framework guiding researchers in the problem-aware selection of metrics. Developed by a large international consortium in a multistage Delphi process, it is based on the novel concept of a problem fingerprint-a structured representation of the given problem that captures all aspects that are relevant for metric selection, from the domain interest to the properties of the target structure(s), dataset and algorithm output. On the basis of the problem fingerprint, users are guided through the process of choosing and applying appropriate validation metrics while being made aware of potential pitfalls. Metrics Reloaded targets image analysis problems that can be interpreted as classification tasks at image, object or pixel level, namely image-level classification, object detection, semantic segmentation and instance segmentation tasks. To improve the user experience, we implemented the framework in the Metrics Reloaded online tool. Following the convergence of ML methodology across application domains, Metrics Reloaded fosters the convergence of validation methodology. Its applicability is demonstrated for various biomedical use cases.
February 2024
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29 Reads
Cancer Informatics
Large-scale, multi-site collaboration is becoming indispensable for a wide range of research and clinical activities in oncology. To facilitate the next generation of advances in cancer biology, precision oncology and the population sciences it will be necessary to develop and implement data management and analytic tools that empower investigators to reliably and objectively detect, characterize and chronicle the phenotypic and genomic changes that occur during the transformation from the benign to cancerous state and throughout the course of disease progression. To facilitate these efforts it is incumbent upon the informatics community to establish the workflows and architectures that automate the aggregation and organization of a growing range and number of clinical data types and modalities ranging from new molecular and laboratory tests to sophisticated diagnostic imaging studies. In an attempt to meet those challenges, leading health care centers across the country are making steep investments to establish enterprise-wide, data warehouses. A significant limitation of many data warehouses, however, is that they are designed to support only alphanumeric information. In contrast to those traditional designs, the system that we have developed supports automated collection and mining of multimodal data including genomics, digital pathology and radiology images. In this paper, our team describes the design, development and implementation of a multi-modal, Clinical & Research Data Warehouse (CRDW) that is tightly integrated with a suite of computational and machine-learning tools to provide actionable insight into the underlying characteristics of the tumor environment that would not be revealed using standard methods and tools. The System features a flexible Extract, Transform and Load (ETL) interface that enables it to adapt to aggregate data originating from different clinical and research sources depending on the specific EHR and other data sources utilized at a given deployment site.
January 2024
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35 Reads
Background The immune microenvironment impacts tumor growth, invasion, metastasis, and patient survival and may provide opportunities for therapeutic intervention in pancreatic ductal adenocarcinoma (PDAC). Although never studied as a potential modulator of the immune response in most cancers, Keratin 17 (K17), a biomarker of the most aggressive (basal) molecular subtype of PDAC, is intimately involved in the histogenesis of the immune response in psoriasis, basal cell carcinoma, and cervical squamous cell carcinoma. Thus, we hypothesized that K17 expression could also impact the immune cell response in PDAC, and that uncovering this relationship could provide insight to guide the development of immunotherapeutic opportunities to extend patient survival. Methods Multiplex immunohistochemistry (mIHC) and automated image analysis based on novel computational imaging technology were used to decipher the abundance and spatial distribution of T cells, macrophages, and tumor cells, relative to K17 expression in 235 PDACs. Results K17 expression had profound effects on the exclusion of intratumoral CD8 + T cells and was also associated with decreased numbers of peritumoral CD8 + T cells, CD16 + macrophages, and CD163 + macrophages (p < 0.0001). The differences in the intratumor and peritumoral CD8 + T cell abundance were not impacted by neoadjuvant therapy, tumor stage, grade, lymph node status, histologic subtype, nor KRAS, p53, SMAD4, or CDKN2A mutations. Conclusions Thus, K17 expression correlates with major differences in the immune microenvironment that are independent of any tested clinicopathologic or tumor intrinsic variables, suggesting that targeting K17-mediated immune effects on the immune system could restore the innate immunologic response to PDAC and might provide novel opportunities to restore immunotherapeutic approaches for this most deadly form of cancer.
... To further elucidate the molecular characteristics of High-Risk cells, we performed differential gene expression analysis between High-Risk and Background subpopulations, identifying 323 upregulated genes (Fig. 2e). Among the upregulated genes, several were strongly associated with aggressive tumor phenotypes [44][45][46][47][48], displaying significantly higher expression in High-Risk cells while being markedly downregulated in Background cells (Fig. 2f). For example, KRT17, which is overexpressed in PDAC [48], and C15orf48 have been linked to poor clinical outcomes [44,45,47], while CEACAM6 has been implicated in promoting cancer cell invasion and metastasis in PDAC [46]. ...
May 2024
Journal of Translational Medicine
... Finally, with the success of latent diffusion models (LDMs) (Rombach et al., 2022), the usage of foundation models should be investigated. As LDMs have also been developed in the medical domain (Yellapragada et al., 2024), it is of high interest to study the extent to which they can capture semantic concepts and potentially improve upon existing methods. With the outlook of a recent, powerful foundational model that is based on flow matching (Esser et al., 2024), their usage in a conditional setting for image segmentation can be explored. ...
January 2024
... The Jaccard index is calculated as JAC = T P T P +F P +F N . In the nuclei segmentation literature, the Jaccard index has sometimes been mistakenly referred to as average precision (AP), which can cause confusion with the area under the precision recall curve [13]. To ensure clarity, we consistently refer to this metric as the Jaccard index. ...
February 2024
Nature Methods
... However, the advent of digital image analysis (DIA) and machine learning (ML) technologies has broadened the scope of artificial intelligence (AI) in this field. Over the past few years, a slew of deep learning (DL) based whole slide image (WSI) analysis tools such as QuPath 1 , TIA Toolbox 2 , MONAI 3 , SlideFlow 4 , PHARAOH 5 , WSInfer 6 have been introduced. ...
January 2024
npj Precision Oncology
... To alleviate the burden of manual annotation and enhance the efficiency of analysis, there has been growing interest in utilizing generative models. Early works use Generative Adversarial Networks (GANs) [20] for automatic generation of pathology images [2,10,34]. In recent years, diffusion models [11,31,45,50,61,73,74] have emerged as much more reliable alternatives, generating accurate, high-resolution histopathology images [4,23,48,51,71]. ...
June 2023
Proceedings / CVPR, IEEE Computer Society Conference on Computer Vision and Pattern Recognition. IEEE Computer Society Conference on Computer Vision and Pattern Recognition
... By aggregating the diagnostic information from each patch, patch-based methods can effectively reduce the impact of artifacts or blurred areas within low-quality slides [53]. Combined with hybrid models that integrate classical image processing techniques and CNNs, patch-based approaches have shown promise for achieving high diagnostic accuracy in low-quality imaging environments [54]. Collectively, these methodologies offer a comprehensive toolkit for improving AI-driven diagnostics in resource-constrained settings [38,39]. ...
May 2023
Computer Methods and Programs in Biomedicine
... To provide a more comprehensive evaluation of the segmentation models, additional performance metrics beyond Mask IoU were included. While Mask IoU is commonly used to assess the overall overlap between predicted segmentation masks and the ground truth, it does not fully capture boundary accuracy, which is critical in medical imaging applications such as liver segmentation 47,48 . Trimap IoU was introduced to specifically evaluate segmentation performance near object boundaries. ...
February 2023
... Digital pathology has transformed cancer diagnosis and prognosis prediction through computational methods that can extract complex patterns directly from image data, enabling sophisticated tasks such as survival prediction, prognosis assessment, and treatment response estimation [5]. Nevertheless, the development and deployment of these computational models face significant challenges due to the labor-intensive nature of data collection and annotation [6], particularly when developing specialized models for the vast array of diagnostic categories and rare diseases encountered in clinical practice. ...
March 2023
Bioinformatics
... Integrating artificial intelligence (AI) into medical diagnostics has considerably enhanced diagnostic accuracy and consistency. This integration is particularly evident in the realm of chest X-ray interpretation, where AI technologies, notably Convolutional Neural Networks (CNNs) such as DenseNet121, have shown considerable capability in providing detailed and consistent interpretations [6][7][8][9][10][11]. The effectiveness of these AI models is primarily attributed to the extensive public databases available, including Chexpert, NIH, Padchest, and MIMIC [12][13][14]. ...
January 2023
... Different stain normalization techniques like Macenko and Vahadane methods were proposed to enhance model performance in classifying metastatic tissue slides. Additionally, it was confirmed in (37) that utilizing multiple slides to construct a representative reference for color normalization has shown promising results in improving computational pathology robustness and integrity. Color stain normalization plays a crucial role in tasks like image retrieval, where differences in colorization can impact the accuracy of analysis. ...
January 2023
IEEE Open Journal of Engineering in Medicine and Biology