arXiv AI

Self-training for cross-centre coronary vessel segmentation in X-ray angiography using pre-contrast frame subtraction

The study investigates self‑training for coronary vessel segmentation in X‑ray angiography, using pseudo‑labels from an nnU‑Net model trained on the ARCADE dataset and a contrast map derived from pre‑contrast frame subtraction. Six models were evaluated on ARCADE and two external datasets (XCAD and XACV); first‑round self‑training improved performance over baseline and a fine‑tuned control, with the XCAD model achieving a 2.7‑point Dice score increase. A second self‑training round yielded no further gains, and the benefit of self‑training was found to depend largely on the sensitivity of the initial pseudo‑label generator.

arXiv Computer Vision
Sep 25

ConPro: Contrast Projection Pretraining for Label-Efficient Vessel Segmentation in DSA Sequences

ConPro introduces a self‑supervised pretraining method for vessel segmentation in digital subtraction angiography (DSA) by using a contrast projection target— the normalized drop of each pixel below its temporal median. On the DIAS and DSCA datasets, ConPro outperforms training from scratch across 10%, 20%, and 50% labeled data, and it is the best among compared methods on DSCA at 20% and 50% labels. When combined with semi‑supervised training, ConPro‑derived weights boost the UniMatch baseline by 0.5–2.0 Dice points and 0.9–2.3 clDice points, achieving 75.4 Dice on DIAS and 81.3 on DSCA.

By Xinge Guo, Yuanhao Wang, Liqi Shu, Yang Liu, Min Xu
arXiv Computer Vision
Oct 21

Vascular anatomy-aware self-supervised pre-training for X-ray angiogram analysis

The paper introduces VasoMIM, a vascular anatomy‑aware masked image modeling framework for X‑ray angiogram analysis, which uses an anatomy‑guided masking strategy and an anatomical consistency loss to learn robust vascular representations. It also presents XA‑170K, the largest pre‑training dataset for X‑ray angiograms. Experiments on six datasets and four downstream tasks show that VasoMIM outperforms existing methods and achieves state‑of‑the‑art performance.

By De-Xing Huang, Chaohui Yu, Xiao-Hu Zhou, Tian-Yu Xiang, Qin-Yi Zhang, Mei-Jiang Gui, Rui-Ze Ma, Chen-Yu Wang, Nu-Fang Xiao, Fan Wang, Zeng-Guang Hou
arXiv AI
Sep 25

Med-AR: Autoregressive Vision-Language Pretraining for Long-Tailed Chest X-Ray Classification and Uncertainty-Aware Evaluation

Med-AR introduces two autoregressive vision‑language models, Med‑AR‑8B and Med‑AR‑2B, pretrained on structured radiology reports, abnormality‑focused text, and region annotations to address long‑tailed chest X‑ray classification. The models outperform existing contrastive, self‑supervised, and supervised encoders—including Med‑CLIP, CheXFound, EVA‑Base, ARK, and BioViL‑T—across PadChest, MIMIC‑CXR, and CheXpert, achieving higher mean AUROC and AUPRC for head, medium, and tail findings and lower excess area under the risk‑coverage curve. Med‑AR also demonstrates improved selective‑prediction performance, with Med‑AR‑8B raising tail‑label mean AUPRC on MIMIC‑CXR from 0.1033 to 0.1441 and Med‑AR‑2B delivering the strongest discrimination on PadChest.

By Janhavi Prabhu, Sahil, Akshay V, Shivam Shukla, Manoj Tadepalli, Preetham Putha
arXiv Machine Learning
Oct 16

L2GSSL: Label-Efficient Local-to-Global Self-Supervised Learning for Volumetric Healthcare Data

L2GSSL is a self‑supervised learning framework designed for volumetric healthcare data, particularly CT scans. It decomposes pretraining into intra‑slice and inter‑slice representation spaces, using a slice encoder for local, view‑invariant features and a global encoder to aggregate tokens for volumetric context. On the LIDC‑IDRI lung nodule malignancy classification task, L2GSSL achieves high AUROC scores with only 10–25% of labels, outperforming other self‑supervised baselines and approaching the performance of fully supervised models.

By Po-Cheng Cheng, Hung-Hsuan Chen
arXiv AI
Jul 14

A Unified Framework for Comprehensive Cardiac CT Segmentation and Phenotyping: Human-in-the-Loop Data Annotation, Vision Foundation Model Development, Multicenter Evaluation and Clinical Validation

arXiv:2607. 11287v1 Announce Type: cross Abstract: Comprehensive quantification of cardiac structures from computed tomography (CT) remains limited not by data availability but by the scalability of measurements, which makes routine use impractical.

By Pooya Mohammadi Kazaj, Leo Fridolin Weber, Wen Xie, Seyed Amir Ahmad Safavi-Naini, Anselm Stark, Giovanni Baj, Ali Mokhtari, Toshiya Yoshida, Christoph Ryffel, Taishi Okuno, Yoshihiro Akashi, Ronny R. Buechel, Thomas Pilgrim, Waldo Valenzuela, George C. M. Siontis, Xiaowei Xu, Moritz Hundertmark, Stephan Windecker, Christoph Grani, Isaac Shiri
arXiv Machine Learning
Jul 27

CARDIAG: A Dense Segment Classification Benchmark of Deep Learning Architectures for Coronary Angiography

arXiv:2607. 22139v1 Announce Type: cross Abstract: Accurate pixel-level classification of coronary angiograms is critical for cardiovascular disease assessment, yet the field lacks standardized evaluation protocols.

By Dominik Bernard Lau, Hubert Malinowski, Jerzy Szyjut, Adam Brzeski, Tomasz Dziubich, Rados{\l}aw Targo\'nski, Tomasz Figatowski, Natalia Zieli\'nska
arXiv Machine Learning
Oct 22

From Theory to Decision Rule: Calibrating the Noisy-Label Crossover for Vision-Language Model Weak Supervision Across Three Medical-Imaging Benchmarks

The study investigates when adding zero‑shot pseudo‑labels from vision‑language models (VLMs) to small expert‑labelled medical imaging datasets ceases to improve, and may even degrade, classifier performance. Across three benchmarks—PatchCamelyon, ISIC 2019, and NIH ChestX‑ray14—the crossover point occurs after roughly 20–50, 100, and 250–500 expert labels, respectively, with additional pseudo‑labels reducing macro‑AUC by up to 0.14 points. The analysis shows that the VLM’s labeling quality, rather than the student model size, limits performance, and a simple bias‑variance rule can predict the benefit of pseudo‑labels in most settings.

By Bruce Changlong Xu, Jose K. James, Alexander J. Ryu
arXiv Computer Vision
Aug 26

Model Effect or Label Effect? Refined Annotations and a Human-Referenced Benchmark for Pulmonary Embolism Segmentation

The study investigates how refined annotations versus model training changes affect pulmonary embolism segmentation performance. By re‑annotating 149 CT pulmonary angiography cases and evaluating two pretrained nnU-Net models, the authors find that improving annotation quality increases the Dice similarity coefficient (DSC) by 0.143–0.188, far exceeding the 0.028 DSC change from altering training datasets. A new human‑referenced benchmark model (nnPE) was trained and publicly released, though it performed below all annotators in paired comparisons.

By Qihang Sun, Zhongxiao Liu, Bailiang Jian, Shenman Qiu, Jingyuan Wang, Lei Zhang, Lixiang Xie, Jiazhen Pan, Christian Wachinger