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Dielectric characterization has significant potential in several medical applications, providing valuable insights into the electromagnetic properties of biological tissues for disease diagnosis, treatment planning, and monitoring of therapeutic interventions. This work presents the use of a custom-designed electromagnetic characterization system, based on an open-ended coaxial probe, for discriminating between benign and malignant breast tissues in a clinical setting. The probe's development involved a well-balanced compromise between physical feasibility and its combined use with a reconstruction algorithm known as the virtual transmission line model (VTLM). Immediately following the biopsy procedure, the dielectric properties of the breast tissues were reconstructed, enabling tissue discrimination based on a rule-of-thumb using the obtained dielectric parameters. A comparative analysis was then performed by analyzing the outcomes of the dielectric investigation with respect to conventional histological results. The experimental procedure took place at Complejo Hospitalario Universitario de Toledo-Hospital Virgen de la Salud, Spain, where excised breast tissues were collected and subsequently analyzed using the dielectric characterization system. A comprehensive statistical evaluation of the probe's performance was carried out, obtaining a sensitivity, specificity, and accuracy of 81.6%, 61.5%, and 73.4%, respectively, compared to conventional histological assessment, considered as the gold standard in this investigation.
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Rationale and objectives: Clinical research is crucial for evaluating new medical procedures and devices. It is important for healthcare units and hospitals to minimize the disruptions caused by conducting clinical studies; however, complex clinical pathways require dedicated recruitment and study designs.This work presents the effective introduction of novel microwave breast imaging (MBI), via MammoWave apparatus, into the clinical routine of an operative screening and diagnostic breast imaging department for conducting a multicentric clinical study. Materials and methods: Microwave breast imaging, using MammoWave apparatus, was performed on volunteers coming from different clinical pathways. Clinical data, comprising demographics and conventional radiologic reports (used as reference standard), was collected; a satisfaction questionnaire was filled by every volunteer. Microwave images were analyzed by an automatic clinical decision support system, which quantified their corresponding features to discriminate between breasts with no relevant radiological findings (NF) and breasts with described findings (WF). Results: Conventional breast imaging (DBT, US, MRI) and MBI were performed and adapted to assure best clinical practices and optimum pathways. 180 volunteers, both symptomatic and asymptomatic, were enrolled in the study. After microwave images' quality assessment, 48 NF (15 dense) and 169 WF (88 dense) breasts were used for the prospective study; 48 (18 dense) breasts suffered from a histology-confirmed carcinoma. An overall sensitivity of 85.8 % in breasts lesions' detection was achieved by the microwave imaging apparatus. Conclusion: An optimum recruitment strategy was implemented to assess MBI. Future trials may show the clinical usefulness of microwave imaging, which may play an important role in breast screening.
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OBJECTIVE:: To assess the clinical performance of the halo sign in tomosynthesis and synthesized 2D mammography, and to identify age groups where its diagnostic value may be greater. METHODS:: 183 patients with nodules were recalled from the breast screening programme (with tomosynthesis and 2D synthesized mammograms). The patients were separated into two groups, 45-49 years and 50-69 years, and depending on the presence or not of halo sign. We calculated the predictive values for the different age groups. RESULTS:: In 45-49 years group, 86 nodular lesions were recalled, 66 (76.7%) with positive halo sign and 20 (23.3%) with negative halo sign. In positive halo sign group, biopsy was considered in 23 (34.8%), with histological features of benignity. In 50-69 years group, 98 nodular lesions from 97 patients were recalled, 51 (52%) with positive halo sign and 47 (48%) with negative halo sign. In positive halo sign group, biopsy was considered in 13 (25.5%); four (30.8%) were malignant and nine (69.2%) were benign. CONCLUSION:: Halo sign could be considered as a marker of benign lesion in females < 50 years. In females ≥ 50 years, other breast imaging techniques should be considered, with or without histological studies, to rule out malignancy. ADVANCES IN KNOWLEDGE:: The trend of a positive halo sign to act as a marker of benign lesion could be improve the recall rate and positive predictive values in the breast screening programme with tomosynthesis and synthesized 2D mammography, especially in young females.