MRI Terms Demystified

You hear lots of jargon terms in reference to MRI scans, but what does it all mean?

• FSE : Fast Spin Echo. This is when several 180 RF pulses quickly fill K-Space, which can be combined with half scan techniques for even faster MRI scans.
• DE-FSE/FIR : Driven Equilibrium FSE – 180 and 90 RF pulse added to the end of FSE echo train to restore longitudinal magnetization, use to increase T2 weighting.
• FIR : Fast Inversion Recovery – IR pulse follows a FSE sequence. Typically used to create a fat suppressed or CSF suppressed image.
• primelFSE : Hitachi proprietary FSE technique enables direct TE entry and custom bandwidth adjustments. This is a great way to get a high quality scan with prostheses.
• Real-IR : Inversion recovery or FIR sequence using “real” reconstruction, opposed to magnitude.
• 3D-GEIR : Gradient Echo Inversion Recovery – Isotropic 3D T1 imaging. Images can be refurbished in custom planes with high image results.
• GE : Gradient Echo – Refocuses echos to produce images that are weighted on TR/TE and Flip Angle.
• SG : Steady State Acquisition Rewound Gradient Echo (SARGE™) – Short TR and rewinder pulses to create a steady state signal with T2* weighting.
• RSSG : RF-Spoiled SG – Uses variable phase shifted excitation pulse to eliminate magnetization build-up, resulting in T1 weighted images.
• TRSG : Time Reversed SG – Simultaneous SE and stimulated echo sampling for T2 weighting.
• BASG : Balanced SARGE – SG sequence with slice, phase, and frequency rewinder pulses. Images are mixed contrast T2/T1. High SNR with bright fluids.
• PBSG : Phase Balanced SARGE – Balanced SARGE with alternating phase RF excitation to preserve image quality where fatty tissue is present.
• RADAR™ : RADial Acquisition Regime – Radial K-space filling technique providing patient motion compensation and excellent image quality. Applicable to FSE, FIR, DWI, SE, BASG.
• PERRM : Phase Encode Reordering to Reduce Motion – Respiratory compensation technique.
• FLUTE™ : FLUoro Triggered Examination – MRA technique, watch for bolus arrival with MR Fluoro, fast switch to 3D MRA when bolus arrives at area of interest.
• TRAQ™ : Time Resolved AcQuisition – MRA technique, uses a ultra fast 3D dynamic scan for observation of blood kinetics.
• VASC™ : Veins and Arteries Sans Contrast – Non-contrast MR angiography technique for renal and peripheral MRA.
• VASC-ASL : VASC Arterial Spin Labeled Non Contrast MRA. Uses inversion pulse to highlight flowing blood.
• PC-MRA : Phase Contrast MRA – Non contrast technique using gradient pulses to velocity encode flowing blood signal (VENC).
• PEAKS™ : Peak Arterial K Space filling method – Central K-space filling techniques used to optimize arterial visualization.
• SSP™: Sloped Slab Profile – Varying excitation tip angle technique equalizes saturation of flowing blood for 3D MRA.
• MTC : Magnetization Transfer Contrast – Additional RF Pulse saturates bound water protein more than free water. Produces increased lesion conspicuity.
• DS : Dual Slice – Simultaneous excitation of multiple slices. Can be applied to a wide range of pulse sequences for increased anatomical coverage.
• FatSep™ : Fat Separation – Fat and water are separated with phase sensitive acquisition and reconstruction. Provides fat only and water only images. Usable with SE, GE, RSSG, and FSE pulse sequences.
• RAPID™ : Rapid Acquisition through Parallel Imaging Design – Reduces k-space coverage requirements to deliver reduced scan time, increased temporal resolution for dynamic scans, and other clinical benefits.
• RAPID™ 3D : Enables slice and/or phase acceleration for 3D acquisitions, useful for dynamic imaging.
• TIGRE™ : 3D T1 Gradient Echo with RF fat saturation for Dynamic breast and abdomen.
• WE : Water Excitation – Binomial pulse alternative to RF fat saturation. Used with 3D GE RSSG for dynamics, BASG for cartilage.
• NATURAL™ : NATural Uniformity Realization Algorithm – Multi-channel RF coil sensitivity normalization.
• BSI : Blood Sensitive Imaging – T2* weighted images depict micro-bleeds, venous blood.