Deep Learning for Detection and Localization of B-Lines in Lung Ultrasound.

Lung ultrasound (LUS) is an important imaging modality used by emergency physicians to assess pulmonary congestion at the patient bedside. B-line artifacts in LUS videos are key findings associated with pulmonary congestion. Not only can the interpretation of LUS be challenging for novice operators, but visual quantification of B-lines remains subject to observer variability. In this work, we investigate the strengths and weaknesses of multiple deep learning approaches for automated B-line detection and localization in LUS videos. We curate and publish, BEDLUS, a new ultrasound dataset comprising 1,419 videos from 113 patients with a total of 15,755 expert-annotated B-lines. Based on this dataset, we present a benchmark of established deep learning methods applied to the task of B-line detection. To pave the way for interpretable quantification of B-lines, we propose a novel "single-point" approach to B-line localization using only the point of origin. Our results show that (a) the area under the receiver operating characteristic curve ranges from 0.864 to 0.955 for the benchmarked detection methods, (b) within this range, the best performance is achieved by models that leverage multiple successive frames as input, and (c) the proposed single-point approach for B-line localization reaches an F 1-score of 0.65, performing on par with the inter-observer agreement. The dataset and developed methods can facilitate further biomedical research on automated interpretation of lung ultrasound with the potential to expand the clinical utility.

Active Tuberculosis Case Finding in Haiti.

In 2010, Haiti suffered from a devastating earthquake; data on the impact on the tuberculosis (TB) epidemic are limited. From January to June 2013, we conducted active case finding at the household level in a slum in Port-au-Prince. Community health workers identified individuals with cough ≥ 2 weeks, and referred them for evaluation. Contact tracing was conducted for patients with active TB. Of an estimated 7,500 residents screened, 394 (5%) had cough and were tested for TB. One hundred (25%) were diagnosed with active TB; 53 (53%) were smear positive. Ninety of these TB index cases provided 317 contacts, and 44 (14%) were diagnosed with active TB; 17 (39%) were smear positive. Overall, 144 TB cases were detected in 6 months (1,920/100,000; national estimate 200/100,000). We found a high burden of undiagnosed TB in Port-au-Prince 3 years after the earthquake. Further assessment of the burden of TB is indicated.