Knowledgebase - PACS Dictionary

Computed Radiography
CR is a cassette based form of digital radiography. It uses a phosphor plate to produce images. CR can be used in standard radiographic settings without modification of equipment. CR uses standard size cassettes and a CR reader to acquire the image in a digital mode.

Digital Imaging Communications in Medicine
DICOM is a standardized computer language that was created to provide a common language for different types of equipment to be able to communicate. It defines both, the way of storing and communicating messages and images.

Digital Radiography
DR systems use some type of x-ray absorbent to form an image. This requires an x-ray room to be retrofitted to utilize this type of device. Also a new room can be built as a DR room. There are two types of systems available; Indirect capture which uses conversion to light, and direct capture which converts x-rays to electrical signals.

Hospital Information System
A hospital information system is a comprehensive, integrated information system designed to manage the administrative, financial and clinical aspects of a hospital. This encompasses paper-based information processing as well as data processing machines.
As an area of medical informatics the aim of an HIS is to achieve the best possible support of patient care and administration by electronic data processing.
It can be composed of one or a few software components with specialty-specific extensions as well as of a large variety of sub-systems in medical specialties (e.g. Laboratory Information System, Radiology Information System).

Health Level 7
HL-7 is an ANSI protocol. It is used as a tool to oversee clinical and administrative data and is used in communication between the HIS (hospital information system) and the RIS (radiology information system). These can combine to form an EMR. (Electronic medical record) the EMR interfaces with most of the ancillary systems used to retrieve data. This can then be viewed in one common format.

Maximum Intensity Projections
A maximum intensity projection is a computer visualization method for 3D data that projects in the visualization plane the voxels with maximum intensity that fall in the way of parallel rays traced from the viewpoint to the plane of projection. This implies that two MIP renderings from opposite viewpoints are symmetrical images.
MIP is used for instance for the detection of lung nodules in lung cancer screening programs which utilize computerized tomography scans. MIP enhances the 3D nature of these nodules, making them stand out from pulmonary bronchi and vasculature.

A modality is defined as any device that sends information to the PACS. Examples are CT, MRI, ultrasound, nuclear medicine, CR readers, DR equipment and film scanners. When you are evaluating what your needs are, you will need to know the present number of modalities and future equipment you might add.

Picture archiving and communication system
A PACS is an acronyme for a medical picture archiving and communication system, a network to store, process and distribute medical imaging data.

A software program which allows for x-rays to be seen in DICOM and that usually comes with tools to enable the user to perform tasks like windowing, leveling, measurement, tiling, cine and other features.

Radiology Information System
A Radiology Information System is used by radiology departments to store, manipulate and distribute patient radiological data and imagery. The system generally consists of patient tracking and scheduling, result reporting and image tracking capabilities.

Volume Rendering Technique
Volume rendering is a technique used to display a 2D projection of a 3D discretely sampled data set.
A typical 3D data set is a group of 2D slice images acquired by a CT or MRI scanner. Usually these are acquired in a regular pattern (e.g., one slice every millimeter) and usually have a regular number of image pixels in a regular pattern. This is an example of a regular volumetric grid, with each volume element, or voxel represented by a single value that is obtained by sampling the immediate area surrounding the voxel. • HIPAA – health insurance portability and accountability act. • SSD - Surface Shaded Display • MPR - Orthogonal and Oblique Multiplanar Reconstructions