ICMP See Internet Control Message Protocol.
IHE See Integrating the Healthcare Enterprise.
IMACS See Image Management and Communication System.
Image A general definition is a visual representation of a real world entity. However a more appropriate definition of a digital image would be an array of numerical values which may be meaningfully rendered as a visible image by means of an algorithm that maps between the array values and the displayed pixel values. The information in each of the pixels will be contained in bytes which will determine its level of grey on the greyscale. See Pixels, Image depth and bytes.
Image depth An image consists of an array of pixels. Every pixel in the image will be made up of a number of bits. A common size for imaging systems is 16 bit pixels. This is known as the image depth, and determines the number of greyscale levels in the image.
Image Management and Communication System (IMACS) Synonymous with "PACS", "Picture Archiving and Communication System." (Though it may sometimes be used to mean a PACS that takes images from more than just the radiology department). See Picture Archiving and Communication System (PACS).
Image Management and Procurement of Systems (IMPRESS) This is a model for the procurement of image and data management systems (PACS and RIS/HIS when purchased with a PACS), in the NHS.
Image Storage Unit (ISU) The online storage can be referred to as the "image storage unit" in a PACS. Copies of all the images of the in-patients, hospitalised patients, or patients attending clinics are held in this form of storage. The images can be removed from the ISU when no longer required online. However they will always be available from the nearline or offline archive. See Working Storage Unit (WSU), Nearline archive and Offline archive.
IMPRESS See Image Management and Procurement of Systems.
Institute for Physics and Engineering in Medicine (IPEM) This is an institute involved in the practice of physics and engineering as applied to medicine and biology. Its main goal is to advance public understanding of the field and to promote research and education in its application to healthcare (http://www.ipem.org.uk/). See British Institute of Radiology (BIR).
Integrating the Healthcare Enterprise (IHE) An initiative by HIMSS and RSNA to establish the integration of all hospital information and imaging systems. Its aim is to encourage manufacturers to establish common protocols that will allow this integration to take place. See Healthcare Information and Management Systems Society (HIMSS), Radiological Society of North America (RSNA), Digital Imaging and Communications in Medicine (DICOM) and Health Level 7 (HL7).
International Society for Optical Engineering (SPIE) Formerly known as the Society of Photo-optical Instrumentation Engineers, this is a body which covers a wide variety of interests from optics to medical imaging. Its plays a significant role in education and emerging technologies and runs many conferences and courses (http://www.spie.org).
Internet Control Message Protocol (ICMP) This is an extension to the internet protocol, which supports error and control messaging. See Transmission Control Protocol/Internet Protocol (TCP/IP).
Internet Service Provider (ISP) Any company that allows subscribers gain access to the Internet, usually via a modem over a telephone line.
IPEM See Institute for Physics and Engineering in Medicine.
ISP See Internet Service Provider.
ISU See Image Storage Unit.