{"doi":"10.1109/tuffc.2025.3623499","title":"Optical Tracking for Freehand Swept Synthetic Aperture Imaging","abstract":"Achieving higher resolution for deeper tissue structures remains a significant challenge in ultrasound (US) imaging due to the inherent limitations of diffraction. Swept synthetic aperture (SSA) techniques, which utilize the motion of a single transducer to effectively increase the imaging aperture, offer a promising solution. Building on SSA, we propose that freehand SSA provides a flexible approach with real-time adaptability to varying patient anatomies. This article introduces the optically tracked SSA (OT-SSA) platform, an approach that integrates external tracking to ensure accurate transducer positioning during freehand sweeps. Key sources of image degradation, such as spatial calibration error, tracking precision, and out-of-plane motion were directly analyzed and addressed within the system. In in vivo quadriceps imaging, OT-SSA reduced average lateral speckle autocorrelation size from 2.33 to 0.49 mm compared to a stationary aperture, demonstrating substantial resolution gains. The results establish OT-SSA as a robust and adaptable approach for high-resolution imaging.","journal":"IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control","year":2025,"id":578582,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":0,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9583,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2025-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1488500,"name":"Jacob Spainhour","orcid":"0000-0001-8219-4360","position":1,"is_corresponding":false},{"id":1279135,"name":"Nazli Javadi Eshkalak","orcid":"0009-0004-5892-8490","position":2,"is_corresponding":false},{"id":411265,"name":"Nick Bottenus","orcid":"0000-0002-4080-2310","position":3,"is_corresponding":false},{"id":1488876,"name":"Anet Sanchez Perez","orcid":null,"position":0,"is_corresponding":true}],"reference_count":38,"raw_metadata":null,"created_at":"2026-07-19T02:58:24.957414Z","pmid":"41115086","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}