[IEEE 2013 IEEE MTT-S International Microwave Workshop Series on RF and Wireless Technologies for Biomedical and Healthcare Applications (IMWS-BIO) - Singapore, Singapore (2013.12.9-2013.12.11)] 2013 IEEE MTT-S International Microwave Workshop Series on RF and Wireless Technologies for Biomedical and Healthcare Applications (IMWS-BIO) - Multi-channel transmit/receive RF coil arrays for cardiac MRI at ultrahigh fields: Design, validation and clinical application