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CT Physics Terms IV
Post-Processing & Data Management
Question | Answer |
---|---|
Incrementation is changed to produce overlapping images that are then used in multiplanar or 3D reformations | overlapping reconstruction |
Image data are used to stacked cross-sectional slices and generate an image in a plane or orientation different from the prospective image. Also called image rendering | image reformation |
This method requires that the operator input the criteria, such as the thickness of the MPR, the plane desired, and the number or incrementation of the resulting planar images | manual MPR |
Refers to the feature that allows the operator to manually change the image plane while the software continually updates the image. This feature permits the operator to use trial and error to obtain the ideal image plane. Also called interactive MPR. | real-time MPR |
Scanner protocols are programmed so that MPRs are automatically generated by the scanner software | scanner-created MPR |
MPR generated directly on the workstation. This allows radiologists the flexibility and interactivity to create images that are suited to the specific clinical situation | workstation-created MPR |
3D reformation method in which the voxels located on the edge of a structure are used to show the outline or outside shell of the structure; it includes only information from the surface of an object. Also known as shaded-surface display (SSD) | surface rendering |
A predetermined CT value limit set by the operator in some types of 3D reformation techniques. The software will include or exclude the voxel depending on whether its CT number is above or below the threshold | threshold CT values |
3D technique. Two common projection displays are the maximum-intensity projection (MIP) and minimum-intensity projection (MinIP). The former selects voxels with the highest value to display; the latter selects voxels with the lowest value | projection displays |
3D technique that selects voxels with the highest value to display | maximum-intensity projection |
3D technique that selects voxels with the lowest value to display | minimum-intensity projection |
A 3D imaging technique that creates a semitransparent representation of the imaged structure. A advantage of this is that all voxels contribute to the image, allowing the image to display multiple tissues and show their relationship to one another | volume rendering |
Each voxel is assigned an ____ based on its Hounsfield units. This determines the degree to which it will contribute, along with other voxels along the same line, to the final image | opacity value |
A form of volume rendering designed to reveal the inside of the lumen of a structure. The technique is also called virtual endoscopy, virtual bronchoscopy, and virtual colonoscopy | endoluminal imaging |
A form of volume rendering designed to reveal the side of airways. This technique is also called endoluminal imaging | virtual bronchoscopy |
A form of volume rendering designed to reveal the inside of the colon. The technique is also called endoluminal imaging | virtual colonoscopy |
Incrementation is changed to produce overlapping images that are then used in multi planar or 3D reformations | region-of-interest editing |
The process of selectively removing or isolating information from the data set by the manual process in which the user identifies and selects data to be saved or removed | manual segmentation |
The process of selectively removing or isolating information from the data set by a method that is fully automated by the software. These methods are usually impractical because of image complexity and the variety of image types and clinical indications. | fully automated segmentation |
Combines many of the benefits of manual and automatic segmentation techniques to selectively remove or isolate information from the data set | semiautomatic segmentation |
Errors in the reformatted image that are introduced when important vessels or other structures are inadvertently edited out of the data set | segmentation errors |
When smooth objects, such as the aorta, appear on the reformatted image to have edges that resemble a flight of stairs. The result when wide slices are used as source images. | stair-step artifacts |
The collection, classification, storage, retrieval, and dissemination of recorded information | informatics |
How information about medical images is exchanged within the radiology departments and through the medical enterprise | imaging informatics |
Information systems that focus on administrative issues, such as patient demographic data, financial data, and patient locations within the hospital | hospital information systems (HIS) |
Information systems that keep track of clinical data | clinical information systems (CIS) |
System that electronically transmits clinician orders to radiology and other departments | computerized physician order entry (CPOE) |
Generic term for a digital patient record | electronic health record (EHR) |
Electronic health records are often composed of this from a variety of sources, including radiology. | electronic medical record (EMR) |
One of the two key elements that form the radiology department's information infrastructure. This is most often designed for scheduling patients, storing reports, patient tracking, protocoling examinations, and billing | radiology information system (RIS) |
One of the two key elements that form the radiology department's information infrastructure. This encompasses a broad range of technologies necessary for storage, retrieval, distribution, and display of images | picture archive and communication system (PACS) |
The study, design, development, implementation, support, or management of computer-based information systems; particularly software applications and computer hardware | information technology (IT) |
Linked computers that are geographically close together | local area network (LAN) |
Computers that are farther apart and must be connected by telephone lines, cables, or radio waves | wide area network (WAN) |
Refers to networks that are linked by a physical connection | wired |
refers to networks that use radio waves to transmit data between computers | wireless |
The geometric arrangement of a computer system. Common ones are bus, star, ring, and tree | topology |
Connections used to attach computers to the network, consisting of cables that are made up of twisted pairs of copper wire | Ethernet |
Comps in this model are either classified as servers or clients. A server is a comp. that facilitates comm btw & delivers info to other comp. The server acts on requests from other networked comp. (the clients), rather than from a person inputting it | client-server network |
Server computers that are integral to the functioning of the PACS | core servers |
Amount of data that can be transmitted between two points in the network in a set period of time | bandwidth |
Binary digits | bits |
Unit of information storage composed of 8 bits of data | bytes |
Method that introduces compression artifacts because not all data are restored; used to transmit images that do not need to be of diagnostic quality. This is sometimes referred to as "conversational" quality | lossy compression |
Method of image compression in which the image that is then decompressed in an exact replica of the original | lossless compression |
Common set of rules and signals that computers on the network use to communicate | protocol |
Describes an arrangement in which two or more components perform the same task, if one element fails the duplication keeps the system functioning while the failed component is repaired; duplication of data to provide an alternative in case of failure | redundancy |
Universally adopted standard for medical image interchange known as the Digital Imaging and Communication in Medicine | DICOM |
An organization that works to develop universal standards for clinical and administrative data throughout the healthcare arena | Health Level Seven |
Image acquisition from the CT scanner to the PACS in which CT data are transferred directly, which allows full spatial resolution and image manipulation capabilities (such as adjusting window width and level) | direct digital capture |
Analog method of image acquisition in which an image on the monitor is converted to a digital format, somewhat similar to a screen capture. Converting CT data in this way loses the original pixel's metrics | frame grabbing |
Monitors used in radiology departments were all adaptations of this | CRT |
Used for monitors in radiology departments | LCD |
Brightness | luminance |
Storage system using devices such as hard drives that are instantly accessible to the user | online archiving |
Storage systems in which data are readily, although not immediately, available. Examples include an optical jukebox or tape library | near-line archiving |
Storage system in which data are kept in a less accessible location, requiring manual intervention to use | off-line archiving |
Storage solution that capitalizes on speed and reliability that divides, or replicates, data among multiple hard drives. These drives are designed to work together and appear to the computer as a single storage device | redundant array of inexpensive disks (RAID) |
Optical storage devices; can be used for long-term data storage. This has a storage capacity of up to 15.9 gigabytes | digital versatile discs |
Roboti storage systems that automatically load and unload optical discs. The devices are also called optical disk libaries, optical jukeboxes, or autochangers | robotic drives |
One of the oldest data storage options used to record computer data; consists of a long narrow strip of plastic with a magnetizable coating, most often packaged in cartridges and cassettes | magnetic tape |
Distribution channels that encompass off-site outpatient clinics or allow on-call radiologists to review studies from home | enterprise-wide distribution |
Distribution channel used to make the Internet a safe medium for the secure transmission of clinical data. Be definition, these overlay another network to provide a particular functionality | virtual private networks (VPN) |
Networks in which each user has the same capabilities and any party can initiate communication. These networks exploit the diverse connectivity and the cumulative data capacity of network participants, rather than using a centralized resource | peer-to-peer (P2P) network |