electromagnetic radiation 电磁辐射 2. ionizing radiation 电离辐射 3. computed tomography 计算机 X 线断层摄影 ( CT ) 4. magnetic resonance imaging 磁共振成像 ( MRI ) 5. radiology inf orm ation system 放射信息系统 ( R I S ) 6. hospital information system 医院信息系统 ( HIS ) 7. picture archiving and communication system 影像归档和通信系统 (PACS) 8. spot shot 点片摄影 9. digital subtraction angiography 数字减影血管造影 ( DSA )