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 radiological image


Regional Attention-Enhanced Swin Transformer for Clinically Relevant Medical Image Captioning

arXiv.org Artificial Intelligence

Automated medical image captioning translates complex radiological images into diagnostic narratives that can support reporting workflows. We present a Swin-BART encoder-decoder system with a lightweight regional attention module that amplifies diagnostically salient regions before cross-attention. Trained and evaluated on ROCO, our model achieves state-of-the-art semantic fidelity while remaining compact and interpretable. We report results as mean$\pm$std over three seeds and include $95\%$ confidence intervals. Compared with baselines, our approach improves ROUGE (proposed 0.603, ResNet-CNN 0.356, BLIP2-OPT 0.255) and BERTScore (proposed 0.807, BLIP2-OPT 0.645, ResNet-CNN 0.623), with competitive BLEU, CIDEr, and METEOR. We further provide ablations (regional attention on/off and token-count sweep), per-modality analysis (CT/MRI/X-ray), paired significance tests, and qualitative heatmaps that visualize the regions driving each description. Decoding uses beam search (beam size $=4$), length penalty $=1.1$, $no\_repeat\_ngram\_size$ $=3$, and max length $=128$. The proposed design yields accurate, clinically phrased captions and transparent regional attributions, supporting safe research use with a human in the loop.


RadSAM: Segmenting 3D radiological images with a 2D promptable model

arXiv.org Artificial Intelligence

Medical image segmentation is a crucial and time-consuming task in clinical care, where mask precision is extremely important. The Segment Anything Model (SAM) offers a promising approach, as it provides an interactive interface based on visual prompting and edition to refine an initial segmentation. This model has strong generalization capabilities, does not rely on predefined classes, and adapts to diverse objects; however, it is pre-trained on natural images and lacks the ability to process medical data effectively. In addition, this model is built for 2D images, whereas a whole medical domain is based on 3D images, such as CT and MRI. Recent adaptations of SAM for medical imaging are based on 2D models, thus requiring one prompt per slice to segment 3D objects, making the segmentation process tedious. They also lack important features such as editing. To bridge this gap, we propose RadSAM, a novel method for segmenting 3D objects with a 2D model from a single prompt. In practice, we train a 2D model using noisy masks as initial prompts, in addition to bounding boxes and points. We then use this novel prompt type with an iterative inference pipeline to reconstruct the 3D mask slice-by-slice. We introduce a benchmark to evaluate the model's ability to segment 3D objects in CT images from a single prompt and evaluate the models' out-of-domain transfer and edition capabilities. We demonstrate the effectiveness of our approach against state-of-the-art models on this benchmark using the AMOS abdominal organ segmentation dataset.


RadCLIP: Enhancing Radiologic Image Analysis through Contrastive Language-Image Pre-training

arXiv.org Artificial Intelligence

The integration of artificial intelligence (AI) with radiology has marked a transformative era in medical diagnostics. Vision foundation models have been adopted to enhance radiologic imaging analysis. However, the distinct complexities of radiological imaging, including the interpretation of 2D and 3D radiological data, pose unique challenges that existing models, trained on general non-medical images, fail to address adequately. To bridge this gap and capitalize on the diagnostic precision required in medical imaging, we introduce RadCLIP: a pioneering cross-modal foundational model that harnesses Contrastive Language-Image Pre-training (CLIP) to refine radiologic image analysis. RadCLIP incorporates a novel 3D slice pooling mechanism tailored for volumetric image analysis and is trained using a comprehensive and diverse dataset of radiologic image-text pairs. Our evaluations demonstrate that RadCLIP effectively aligns radiological images with their corresponding textual annotations, and in the meantime, offers a robust vision backbone for radiologic imagery with significant promise.


A Survey of the Impact of Self-Supervised Pretraining for Diagnostic Tasks with Radiological Images

arXiv.org Artificial Intelligence

Self-supervised pretraining has been observed to be effective at improving feature representations for transfer learning, leveraging large amounts of unlabelled data. This review summarizes recent research into its usage in X-ray, computed tomography, magnetic resonance, and ultrasound imaging, concentrating on studies that compare self-supervised pretraining to fully supervised learning for diagnostic tasks such as classification and segmentation. The most pertinent finding is that self-supervised pretraining generally improves downstream task performance compared to full supervision, most prominently when unlabelled examples greatly outnumber labelled examples. Based on the aggregate evidence, recommendations are provided for practitioners considering using self-supervised learning. Motivated by limitations identified in current research, directions and practices for future study are suggested, such as integrating clinical knowledge with theoretically justified self-supervised learning methods, evaluating on public datasets, growing the modest body of evidence for ultrasound, and characterizing the impact of self-supervised pretraining on generalization.


What Does DALL-E 2 Know About Radiology?

arXiv.org Artificial Intelligence

Generative models such as DALL-E 2 could represent a promising future tool for image generation, augmentation, and manipulation for artificial intelligence research in radiology provided that these models have sufficient medical domain knowledge. Here we show that DALL-E 2 has learned relevant representations of X-ray images with promising capabilities in terms of zero-shot text-toimage generation of new images, continuation of an image beyond its original boundaries, or removal of elements, while pathology generation or CT, MRI, and ultrasound images are still limited. The use of generative models for augmenting and generating radiological data thus seems feasible, even if further fine-tuning and adaptation of these models to the respective domain is required beforehand. DALL-E 2 is a novel deep learning model for text-to-image generation, first introduced by OpenAI in April 2022 [Ramesh et al., 2022]. The model has recently gained widespread public interest due to its ability to create photorealistic images solely from short written inputs [Kather et al., 2022][Conwell and Ullman, 2022][Marcus et al., 2022].


Applications of Manifolds in Machine Learning and Deep Learning(Artificial Intelligence +โ€ฆ

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Abstract: Admittedly, Graph Convolution Network (GCN) has achieved excellent results on graph datasets such as social networks, citation networks, etc. However, softmax used as the decision layer in these frameworks is generally optimized with thousands of iterations via gradient descent. Furthermore, due to ignoring the inner distribution of the graph nodes, the decision layer might lead to an unsatisfactory performance in semi-supervised learning with less label support. To address the referred issues, we propose a novel graph deep model with a non-gradient decision layer for graph mining. Firstly, manifold learning is unified with label local-structure preservation to capture the topological information of the nodes.


The Intrinsic Manifolds of Radiological Images and their Role in Deep Learning

arXiv.org Artificial Intelligence

The manifold hypothesis is a core mechanism behind the success of deep learning, so understanding the intrinsic manifold structure of image data is central to studying how neural networks learn from the data. Intrinsic dataset manifolds and their relationship to learning difficulty have recently begun to be studied for the common domain of natural images, but little such research has been attempted for radiological images. We address this here. First, we compare the intrinsic manifold dimensionality of radiological and natural images. We also investigate the relationship between intrinsic dimensionality and generalization ability over a wide range of datasets. Our analysis shows that natural image datasets generally have a higher number of intrinsic dimensions than radiological images. However, the relationship between generalization ability and intrinsic dimensionality is much stronger for medical images, which could be explained as radiological images having intrinsic features that are more difficult to learn. These results give a more principled underpinning for the intuition that radiological images can be more challenging to apply deep learning to than natural image datasets common to machine learning research. We believe rather than directly applying models developed for natural images to the radiological imaging domain, more care should be taken to developing architectures and algorithms that are more tailored to the specific characteristics of this domain. The research shown in our paper, demonstrating these characteristics and the differences from natural images, is an important first step in this direction.


Multimodal AI in Healthcare: Closing the Gaps

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Healthcare professionals, in their daily routine, make use of multiple sources of data. To arrive to a diagnosis and decide on patient management, they rely on a combination of several types and sources of data: imaging (e.g., Radiology, Pathology, Ophthalmology), time series (e.g., electrocardiograms -- ECG), structured clinical data (e.g., vital signs, lab results) and non-structured data (e.g., clinical notes). Considering the level of expertise required to understand in depth one single data type, it is close to impossible for a single healthcare professional to master all areas. A radiologist has specialized training to read radiological images, but doesn't know as much about internal medicine or surgery. A cardiologist has a deep understanding of ECGs, but normally does not know how to evaluate a pathology slide.


Current use cases for machine learning in healthcare

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Machine learning (ML) is causing quite the buzz at the moment, and it's having a huge impact on healthcare. Payers, providers, and pharmaceutical companies are all seeing applicability in their spaces and are taking advantage of ML today. This is a quick overview of key topics in ML, and how it is being used in healthcare. A machine learning model is created by feeding data into a learning algorithm. The algorithm is where the magic happens.