L5-contrast

L5-contrast - Contrast & Signal-to-noise ratio 2 ) ( )...

Info iconThis preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Contrast & Signal-to-noise ratio 2 ) ( ) ( = 2 1 signal signal contrast- = Contrast types Static contrast T1-weighted T2-weighted T2*-weighted fMRI (BOLD) Dynamic contrast Time of flight (TOF) MRA Velocity-encoded phase contrast (VENC-PC) MRA Perfusion-weighted contrast fMRI (cerebral blood flow) Diffusion-weighted Contrast Relaxation time and image contrast T1-weighted T2-weighted T2*-weighted What determines contrast type? Main pulse-sequence parameters Sequence family (Spin-echo, gradient echo, EPI , etc.) TR TE Flip angle (mainly for gradient-echo related sequences) Preparation-module parameters Spoiler TI (inversion time) Fat saturation Water excitation TR=1.5 s, TE=3.05 ms, Flip angle = 10, TI = 0.8 s Water excitation: ON TR=1.61 s, TE=2.54 ms, Flip angle = 15, TI = 1.1 s Parameters & contrast MPRAGE: 3D gradient echo on Siemens Trio (3T) A simple approximation...
View Full Document

This note was uploaded on 02/07/2009 for the course PSYC 425 taught by Professor Lu during the Spring '08 term at USC.

Page1 / 41

L5-contrast - Contrast & Signal-to-noise ratio 2 ) ( )...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online