PubMed This is the largest biomedical database, made freely available by the National Library of Medicine (NLM), that is cross-searching approximately 5000 journals, including: Journal of X-ray Science and Technology; Skeletal Radiology; Journal of Computer Assisted Tomography; Journal of Digital Imaging; Journal of Radiological Protection; Journal of the American College of Radiology: JACR; Magnetic Resonance Imaging; Pediatric Radiology; Radiologic Technology, and more.