The 2021 SIIM-FISABIO-RSNA Machine Learning COVID-19 Challenge: Annotation and Standard Exam Classification of COVID-19 Chest Radiographs.

We describe the curation, annotation methodology, and characteristics of the dataset used in an artificial intelligence challenge for detection and localization of COVID-19 on chest radiographs. The chest radiographs were annotated by an international group of radiologists into four mutually exclusive categories, including "typical," "indeterminate," and "atypical appearance" for COVID-19, or "negative for pneumonia," adapted from previously published guidelines, and bounding boxes were placed on airspace opacities. This dataset and respective annotations are available to researchers for academic and noncommercial use.

Swallowed sharp foreign bodies (sewing needles): a conservative approach.

A swallowed foreign body, large or small, sharp or pointed should be treated with respect. Its passage in the gastrointestinal tract should be carefully watched and monitored. The patient should be kept under regular and constant observation until such time as the foreign body has either expelled itself or is removed. We report here two cases of sharp foreign bodies ingested by children and successfully managed on conservative lines.