arXiv Computer Vision

When can multi-fragment 2D/3D registration be trusted? Calibrated certification and uncertainty-driven view planning for pelvic fracture fluoroscopy

The paper presents a closed‑loop system for registering segmented CT fracture fragments to fluoroscopy, providing calibrated uncertainty bounds and flagging implausible or ambiguous fragments. After each shot, the system updates all fragment registrations, stops or plans the next view based on whether new views keep fragment positions within their bounds, and uses uncertainty‑driven planning to reduce the number of shots needed. Experiments on simulated fluoroscopy of 60 held‑out pelvic fractures show that 95% of the bounds cover 83% of unflagged fragments, with 91% of those within 5 mm, and that a simple rule requiring no fragment to move beyond its bound reduces false stops from 23% to 6% at a 2 mm threshold. "whyItMatters":"The study demonstrates that calibrated uncertainty and view‑planning can make multi‑fragment 2D/3D registration reliable enough to guide pelvic fracture surgery, potentially improving surgical accuracy and efficiency."

arXiv Computer Vision
Sep 4

Hold-Out Self-Validation Cannot Certify Photogrammetric Accuracy: Saturation and Blindness to Coherent Distortion

The paper argues that internal self-consistency checks cannot guarantee the accuracy of photogrammetric reconstructions, a limitation that is structural rather than a tuning issue. It introduces a track‑leakage‑free hold‑out protocol that withholds a deterministic subset of images and tests each against only 3D points supported by at least two retained images, ensuring no view is evaluated against the structure it helped create. Experiments on diverse datasets show that while the protocol is well‑posed, it saturates at a confidence score of 1.00 and fails to detect coherent distortion, missing large errors that can reach over 100 m. whyItMatters":"The study highlights that hold‑out self‑validation scores, increasingly used as quality evidence for metric deliverables, may be misleading and cannot replace external survey validation."

By Behnam Asadi
arXiv Computer Vision
Oct 16

A Decision-Aware Evaluation Protocol for Uncertainty in Medical Image Segmentation

The paper introduces a decision‑aware evaluation protocol for medical image segmentation uncertainty that separates uncertainty estimation from deferral policy and assesses their joint performance under fixed review budgets. It reports metrics such as fixed‑budget error reduction, risk‑coverage behavior, region‑level review proxies, structural failure modes, and sensitivity to review assumptions. Experiments on retinal vessel, skin lesion, and polyp segmentation with various backbones and uncertainty estimators show that estimator rankings vary with review unit, uncertainty target, and cost model, and that boundary and thin‑structure failures are partly due to annotation ambiguity.

By Saket Maganti, Shreyank N Gowda
Hugging Face Trending Papers
Jul 9

Metrics or Mirage? An Audit of Evaluation Inconsistencies in Colonoscopy Polyp Segmentation Benchmarks

Progress in colonoscopy polyp segmentation is routinely reported through leaderboard comparisons on a small set of public benchmarks. We argue that this apparent progress is difficult to verify: a systematic audit of \textbf{27 papers} published between 2015 and 2026 reveals three structural problems in how the community evaluates models.

arXiv AI
2d ago

Risk Control Certifies Rates, Not Magnitudes: An Audit of Selective Fetal Biometry

The paper audits a prenatal ultrasound biometry pipeline that predicts head circumference (HC) while certifying a maximum error rate rather than magnitude. Using two pre‑registered splits of 999 HC18 images, the authors retrain the segmenter three times per split and calibrate a contour‑completeness threshold via exact Clopper–Pearson risk control. Although the certified risk bound (α = 0.10) remains intact, the pipeline still produces a large 271.3 mm error on a single image, and tightening the admissibility region to an anatomically defined range reduces worst‑case errors to about 11 mm while only modestly affecting coverage.

By Zhengshuai Yang, Linna Jiang, Changyun Li, Guihu Zhao
arXiv AI
Oct 27

Conviction Without Evidence: Verdict Stability Is Independent of Visual Grounding in Medical Vision--Language Models

Vision–language models can correctly diagnose medical questions using only the clinical vignette, without the diagnostic image. In experiments on 60 Italian State Examination items, models defended diagnoses derived from a blank placeholder as firmly as those derived from real images, showing no increased fragility. While different adversarial pressures produced distinct dynamics—one leading to a single decisive flip and the other to continual changes—the instability under contentless doubt reflected item ambiguity rather than lack of evidence.

By Federico Felizzi, Francesco Andrea Causio, Bianca Destro Castaniti, Olivia Riccomi, Michele Ferramola, Vittorio De Vita, Alessandro Tosi, Antonio Cristiano, Alessia Longo, Lorenzo De Mori, Chiara Battipaglia, Melissa Sawaya, Luigi De Angelis, Marcello Di Pumpo, Alessandra Piscitelli, Pietro Eric Risuleo, Giulia Vojvodic, Mariapia Vassalli, Nicolo Scarsi, Manuel Del Medico
arXiv AI
Sep 11

Safe to Stop? Risk-Constrained Stopping for Sequential Clinical Diagnosis Agents

The paper introduces Cros, a risk‑constrained stopping layer for sequential clinical diagnosis agents that determines when to stop testing and make a diagnosis. Cros combines state‑wise error ranking, policy design on disjoint development splits, and exact tests of selective diagnostic error to provide finite‑sample guarantees. On a MIMIC‑derived abdominal‑pain benchmark, Cros achieves higher state‑error AUROC and lower selective error rates compared to baseline stopping methods, though its performance varies across development resplits.

By Yuexin Wu, Vasile Rus
arXiv Machine Learning
Oct 8

SpatialUQ: Post-Hoc Uncertainty Quantification from Spatial Consistency in Black-Box Vision Models

SpatialUQ is a post‑hoc uncertainty quantification method that uses only the output probabilities of frozen black‑box vision models. It computes the Jensen‑Shannon divergence between the global prediction and the mean of five fixed spatial crops across six deterministic forward passes, assuming that trustworthy predictions are spatially consistent. On the NIH ChestX‑ray14 dataset, SpatialUQ’s Multicrop Uncertainty Score (MUS) achieves a 0.784 failure‑detection AUC—significantly higher than MC‑Dropout—while also providing superior native calibration and improving further when fused with other uncertainty signals.

By Md Kawsher Mahbub, Milon Biswas, Mirza Niaz Morshed, Wei Yu
arXiv Computer Vision
Oct 22

Certified Abstention for Provably-Unidentifiable Index-Phase Recovery in Image Registration

The paper introduces a certified abstention approach for image registration, distinguishing between recoverable and provably-unidentifiable regions in reference-perturbed sampled imaging. It establishes a resolution threshold that separates these regimes and provides a framework that exactly recovers identifiable areas while abstaining from unreliable ones, avoiding hallucinated structures. Experiments on scanning, rolling‑shutter, and cryo‑electron‑microscopy systems confirm that the method abstains where classical or learned estimators fabricate artifacts.

By Dinh Tuan Nguyen, Trong Nhan Nguyen, Vu Nguyen Minh Hung, Tien Minh Khoi Nguyen, Jaeyeop Choi, Sudip Mondal, Jae Sung Ahn, Junghwan Oh