Principles ofUltra-Fast MR Imaging

Table of Contents

Principles ofUltra-Fast MR Imaging

How Fast is Fast?

Why Does MRI Take So Long?

The MR Signal is TRANSIENT:

The MR Signal is REFRACTORY:

Imaging Time =

FLASH Imaging

ìMR Flouroscopyî

TURBO-FLASH

To Make An Image:

To Complete Sampling in 10 msec

In Conventional MRISampling is ApportionedInto Brief EpisodesSeparated by a ìTRî Period

Properties of K-Space

Conventional K-SpaceTrajectory

Instascan k-space Trajectory

Single Shot k-space coverage

Extending the Readout ImprovesResolution in the Phase direction

Conjugate Synthesis MayMay Be Used to Reduce TE

Mosaic Imaging

Conjugate Synthesis Can GiveBetter Resolution at Long TE

Multiple Shot & Conjugate SynthesisMethods may be Combined

Echo-Planar ImagingClinical Experience

Email: mscohen@ucla.edu

Home Page: www.brainmapping.org

Other information:
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