UltrasODM: A Dual Stream Optical Flow Mamba Network for 3D Freehand Ultrasound Reconstruction
Mayank Anand, Ujair Alam, Surya Prakash, Priya Shukla, Gora Chand Nandi, Domenec Puig
TL;DR
UltrasODM addresses drift and reliability issues in 3D freehand ultrasound reconstruction by coupling a dual-stream motion model with a contrastive frame embedding and a Dual Mamba temporal encoder. A HITL safety loop leverages Monte Carlo uncertainty, saliency explanations, and clinician-guided prompts to guide reacquisition, aiming for safer and more trustworthy clinical workflows. The approach yields reductions in drift, distance error, and Hausdorff distance on a clinical freehand dataset, while providing per-frame uncertainty and explainability. The work emphasizes system-level integration, real-time considerations, and ethical compliance, and releases public code to facilitate adoption and benchmarking in healthcare AI.
Abstract
Clinical ultrasound acquisition is highly operator-dependent, where rapid probe motion and brightness fluctuations often lead to reconstruction errors that reduce trust and clinical utility. We present UltrasODM, a dual-stream framework that assists sonographers during acquisition through calibrated per-frame uncertainty, saliency-based diagnostics, and actionable prompts. UltrasODM integrates (i) a contrastive ranking module that groups frames by motion similarity, (ii) an optical-flow stream fused with Dual-Mamba temporal modules for robust 6-DoF pose estimation, and (iii) a Human-in-the-Loop (HITL) layer combining Bayesian uncertainty, clinician-calibrated thresholds, and saliency maps highlighting regions of low confidence. When uncertainty exceeds the threshold, the system issues unobtrusive alerts suggesting corrective actions such as re-scanning highlighted regions or slowing the sweep. Evaluated on a clinical freehand ultrasound dataset, UltrasODM reduces drift by 15.2%, distance error by 12.1%, and Hausdorff distance by 10.1% relative to UltrasOM, while producing per-frame uncertainty and saliency outputs. By emphasizing transparency and clinician feedback, UltrasODM improves reconstruction reliability and supports safer, more trustworthy clinical workflows. Our code is publicly available at https://github.com/AnandMayank/UltrasODM.
