Nodule Chest X-ray dataset originating from Japan, year ~2000 - official site http://db.jsrt.or.jp/eng.php.
Chest X-rays provided are scanned films with high quality digital camera. Each nodule case contains 1 nodule only, which is rated by 20 different radiologists - AUC ranging from 0.72 to 0.89. This is an ideal dataset to test nodule detection performance on different levels of nodule subtlety.
Full dataset description provided in https://www.ajronline.org/doi/pdf/10.2214/ajr.174.1.1740071.