Author,Title,Journal,ISSN,Publisher,Date,Volume,Number,Page,URL,URL(DOI) Taniuchi Ryousui and Ishida Mai and Ueta Ayami and Miyamoto Syohei and Hirai Yuka and Aoji Chiaki and Kiyoto Yumi,A Case of Pneumopericardium with Changing Echo Characterization of Pericardial Effusion,Japanese Journal of Medical Ultrasound Technology,18814506,Japanese Society of Sonographers,2021-02-01,46,1,22-28,https://cir.nii.ac.jp/crid/1390568456356178816,https://doi.org/10.11272/jss.323