|In the context of medical imaging, a modality is device or system that generates images of the internals of the human body. Examples of specific modalities include computed tomography (CT) scanners and nuclear medicine (NM) cameras. In addition to images, some modalities can also create other evidence objects such as Grayscale Softcopy Presentation States for the consistent viewing of images or Evidence Documents containing measurements.
Modalities are typically not included as part of the PACS, mainly because they are already exist, independently of a PACS. An exception to this is Computerized and Digital Radiography (CR/DR). The reason to include CR/DR modalities as part of PACS, is that their benefits are really only realized when using a PACS system to archive, view and communicate the images.