Glossary

ACGD	Advanced Concept Gradient Driver
AGP	Applications Gateway Processor [Board]
AP	Array Processor Board
APM	Analog Power Monitor [Board]
APS	Auto prescan: Auto-adjustment of data acquisition (scan) parameters
APS	Acquisition Processing System [Board]
AVS	Auto voxel shim
AWS	Automatic Water Suppression
BRM	Body Resonance Module
CAN	Control Area Network [Board]
CCC	CAN Core Communication [Board]
CRM	Cardiac Resonance Module
CRT	Cathode Ray Tube
CRYOGEN	A substance for producing low temperatures. Liquid helium is the cryogen used to cool the magnet to approximately 4 Kelvin (269 C or 452 F).
CRYOSTAT	An apparatus maintaining a very low constant temperature. The cryostat consists of one concentric, cylindrical container housed in an outer vacuum tight vessel. The magnet and shim coils are mounted in the inner container. The container is filled with liquid helium. The shields surrounding the inner container are kept cold by a refrigeration device.
CV	Control variable
DCB	Driver Control Board
DEWAR	A container with an evacuated space between two highly reflective walls used to keep low temperature substances at nearconstant temperatures. Liquid helium is usually stored and shipped in dewars
DM	Driver Module
DRF1	Digital Receive Filter 1 [Board]
DSP	Digital Signal Processing
EXCLUSION ZONE	Area where the magnetic flux density is greater than five gauss. Personnel with cardiac pacemakers, neurostimulators and other biostimulation devices must NOT enter this zone. Signs are posted outside the five gauss line alerting personnel of this requirement. Since the magnetic field is threedimensional, signs are also posted on floors above and below the Magnet Room in which the five gauss line exists.
FERROUS MATERIAL	Any substance containing iron which is strongly attracted by a magnetic field.
FO	Fiber Optic
FOV	Field of View
FPIO	Front Panel Input/Output [Board]
FWHM	Full Width Half Max
GAUSS (G)	A unit of magnetic flux density. The earths magnetic field strength is approximately one half gauss to one gauss depending on location. The internationally accepted unit is the tesla (1 Tesla = 10,000G and 1 milli Tesla =10G).
GP	Gradient Processor [Board]
GRADIENT	The amount and direction of the rate of change in space of the magnetic field strength. In the magnetic resonance system, gradient amplifiers and coils are used to vary the magnetic field strength in the x, y, and z planes.
GRx	Graphic Prescription
HFA	High Fidelity Gradient Amplifier
HFD	High Fidelity Gradient Driver
HOMOGENEITY	Uniformity. The homogeneity of the static magnetic field is an important quality of the magnet.
ICN	Image Compute Node. A component with an internal operating system (similar to a PC) used for Image reconstruction in the VRE. Contains hard drives and an operating system
ICW	Installation Calibration Wizard. This wizard is available in two different modes: Install and Upgrades. It can be found in the proprietary Common Service Desktop under the "Calibration" tab. Maintenance mode is available after all calibrations and tasks in the install mode are complete.
IFCC	Image file create and cleanup
INFINIBAND	High-speed communication, analogous to Ethernet but much higher speed and capacity. Used for transporting large amounts of data for within the volume reconstruction subsystem
IRF	Interface and Remote Functions [Board]
IRF I/O	Interface and Remote Functions Input/Output [Board]
ISOCENTER	Center of the imaging volume ideally located at the magnet center.
ISOGAUSS LINE	An imaginary line or a line on a field plot connecting identical magnetic field strength points.
IT Host	Image Transfer Host [Board]
IT-MGD	Image Transfer-MGD [Board]
LCD	Liquid Crystal Display
LED	Light Emitting Diode
LO	Local Oscillator
LPCA	Low Profile Carriage Assembly
MAGNETIC FIELD (H)	The space around a magnet (or current carrying conductor) which can produce a magnetizing force on a body within it
MAGNETIC RESONANCE (MR)	The absorption or emission of electromagnetic energy by nuclei in a static magnetic field, after excitation by a suitable radio frequency field.
MAGNETIC SHIELDING	Using material (e.g. steel) to redistribute a magnetic field , usually to reduce fringe fields.
MC	MultiCoil
MCD	MultiCoil Driver [Board]
MCQA	Multi Coil Quality Assurance. This is a tool that will check the coil SNR and be able to trend it for each coil over time.
MGD	Multi-Generational Data acquisition [Chassis]
MPS	Manual prescan: Manual adjustment of data acquisition (scan) parameters
MRS	Magnetic Resonance Spectroscopy
MUX	Multiplexor [Board]
NEX	Number of excitations
OM	Oxygen Monitor
OW	Operator Workspace
PAC	Physiological Acquisition Controller
PCI	Peripheral Component Interconnect
PDU	Power Distribution Unit
PMC	PCI Mezzanine Connecter
PP	Penetration Panel
PRESS	Point-resolved spectroscopy, basis for probe-p PSD
PROBE/Q	Automated analysis and display of PROBE/SV data
PROBE/SV	PROton Brain Exam Single Voxel spectroscopy using automated STEAM or PRESS pulse sequence
PS	Power Supply
PSD	Pulse sequence data base
PT	Patient Transport or Patient Table
QUENCH	Condition when a superconducting magnet becomes resistive thus rapidly boiling off liquid helium. The magnetic field reduces rapidly after a quench.
RADIO FREQUENCY (RF)	Frequency intermediate between audio frequency and infrared frequencies. Used in magnetic resonance systems to excite nuclei to resonance. Typical frequency range for magnetic resonance systems is 580 Mhz.
RADIO FREQUENCY SHIELDING	Using material (e.g. copper, aluminium, or steel) to reduce interference from external radio frequencies. A radio frequency shielded room usually encloses the entire magnet room.
RECON	Process that creates an image or spectrum from data acquired with a Signa MRI scanner.
RESONANCE	A large amplitude vibration caused by a relative small periodic stimulus of the same or nearly the same period as the natural vibration period of the system. In magnetic resonance imaging, the radio frequency pulses are the periodic stimuli which are at the same vibration period as the hydrogen nuclei being imaged.
RF	Radio Frequency
RF-DIF	RF-Digital Interface [Board]
RFI	RF Interface [Module]
ROI	Region of Interest
RPC	Remote Control Panel (TwinSpeed only)
RRF	Remote RF [Chassis]
RSP	Real-time sequence control parameters
S/C	Super Conducting
SAT	Saturation, a signal suppression technique
SCP	Scan Control Processor [Board]
SCSI	Small Computer System Interface
SGA	Switchable Gradient Amplifier [Module]
SHIELD COOLER COLD HEAD	An external refrigeration device which maintains the shields inside the cryostat at a constant temperature.
SHIM COILS	Shim coils are used to provide auxiliary magnetic fields in order to compensate for inhomogeneities in the main magnetic field due to imperfections in the manufacturing of the magnet or affects of steel in the surrounding environment.
SHIMMING	Correction of inhomogeneity of the main magnetic field due to imperfections in the magnet or to the presence of external ferromagnetic objects.
SMC	System Monitor and Control
SPU	Signal Processing Unit
SRF	Scalable RF [Cabinet] (this is same as SRFD)
SRF/TRF	Sequencer Related Function / Trigger and Rotation Function [Board]
SRFD	Scalable RF Driver [Cabinet]
SRFD2	Scalable RF Driver 2 [Cabinet]
SRI	Scan Room Interface [Module]
SSM	System Support Module
STEAM	Stimulated echo acquisition mode, basis for PROBE-s PSD
STIF	SRF/TRF Interface [Board]
SUPER CONDUCTING MAGNET	A magnet whose magnetic field originates from current flowing through a superconductor. Such a magnet is enclosed in a cryostat.
SUPERCONDUCTOR	A substance whose electrical resistance essentially disappears at temperatures near zero Kelvin. A commonly used superconductor in magnetic resonance imaging system magnets is niobiumtitanium embedded in a copper matrix
T1	The characteristic time constant for the magnetizations return to the longitudinal axis after being excited by an RF pulse. Also called Spin Lattice or Longitudinal Relaxation Time.
T1-Weighted	Scan protocols that allow the T1 effects to predominate over the other relaxation effects.
T2*	The characteristic time constant for loss of transverse magnetization and MR signal due to T2 and local field inhomogeneties. Since such inhomogeneities are not compensated for by gradient reversal, contrast in gradient-echo images depends on T2*.
T2*-Weighted	Scan protocols that allow the T2* effects to predominate over the other contrast effects. There are three primary gradient echo pulse sequences that can be used to produce varying T2*-weighted images: Gradient Echo, SPGR, and SSFP.
T2	The characteristic time constant for loss of phase coherence among spins, caused by their interaction, and the resulting loss in the transverse-magnetization MR signal. Also referred to as Spin-Spin or Transverse Relaxation Time.
T2-Weighted	Scan protocols that allow the T2 effects to predominate over the other contrast effects.
TE Min	The shortest possible TE time for a given prescription, used to minimize flow dephasing and T2 effects.
TE	See Time to Echo.
TE1	The time from the middle of the first excitation pulse to the middle of the first readout in an Asysmmetrical Spin Echo pulse sequence.
TAC	Twin Accessory Cabinet (TwinSpeed only)
TE	Echo time
TE2	The time between the middle of the first excitation pulse and the middle of the second readout in an Asysmmetrical Spin Echo pulse sequence.
TESLA (T)	The internationally accepted unit of magnetic flux density. One tesla is equal to 10,000 gauss. One milli Tesla is equal to 10 gauss.
TGWC	TwinSpeed Gradient Water Cooler
Time to Echo (TE)	The time between the center of the excitation pulse and the peak of the echo, which usually occurs at the center of the readout.
Time-of-Flight (TOF) Angiography	A 2D or 3D imaging technique that relies primarily on flow-related enhancement to distinguish moving from stationary spins in creating MR angiograms. Blood that has flowed into the slice will not have experienced RF pulses and will therefore appears brighter than stationary tissue.
TOF Angiography	See Time-of-Flight Angiography.
TIR	Tardis Image Receive
TNS	Transient Noise Suppressor [Module]
TP	Test Point
TPS	Transceiver and Processing subsystem
TPS	Transceiver Processing and Storage
TR	Repetition time
TRM	Twin Resonance Module
TRM	Twin Resonance Module (TwinSpeed only)
TSCC	TwinSpeed Cooling Cabinet
UART	Universal Asynchronous Receive Transmit [Device]
UTNS	Universal Transient Noise Suppressor [Board]
VOI	Voxel of interest
VRE	Volume Recon Engine
WARP	Waveform and Rotation Processor
WC	Water Chiller
WIM	Workspace Interface Module
WS	Water Suppression