Exchange of Quantitative Computed Tomography Assessed Body Composition Data Using Fast Healthcare Interoperability Resources as a Necessary Step Toward Interoperable Integration of Opportunistic Screening Into Clinical Practice: Methodological Development Study - Yutong Wen; Vin Yeang Choo; Jan Horst Eil; Sylvia Thun; Daniel Pinto dos Santos; Johannes Kast; Stefan Sigle; Hans-Ulrich Prokosch; Diana Lizzhaid Ovelgönne; Katarzyna Borys; Judith Kohnke; Kamyar Arzideh; et al. (Journal of Medical Internet Research)