- Sequence used to identify regions of fatty infiltration and help identify adenomas.
- aka chemical shift imaging
- Relies of differences in the precessional frequency of Hydrogen in fat and water molecules.
- Gradient echo image with TE set to a time where fat and water spins are 180 degrees out of phase causing fat and water signal components within a voxel to destructively interfere and reduce the brightness of the pixel.
- Degree of signal change depends on the ration of fat/water. All fat or all water, no signal drop (compared to in-phase image) 50/50 causes total signal loss
- OOP images identified by dark bands at fat water interfaces
- Select the shortest OOP TE to get best T1 contrast and largest number of slices
- Exact TE depends on filed strength
Popular Posts
-
Normal MRI Anatomy The pectoralis tendon is best seen on axial T1 and T2-weighted images as a curvilinear low-signal band inserting o...
-
Axial Plane: Prescribe plane perpendicular to midshaft of the proximal phalanx of the thumb. Scan from 1st carp-metacarpal joint th...
-
--> Routine shoulder protocols are the most variable, but most include SHOULDER MRI SEQUENCES ... -
--> Fast FLAIR sequence structure. Typical FSE sequence structure of multiple 180° pulses is modified by addition of a 180° inver...
-
Electromanetism tells us that a current carrying conductor e.g. a piece of wire, produces a magnetic field encircling it. When the wire is... -
To obtain standardized cardiac imaging planes in the shortest number of steps possible. The standard planes include Vertical Long Axis (V...
-
Patients should be fasted for at least four hours. Oral water and an anti-peristaltic agent are given. Optimal technique requires a quad...
No comments:
Post a Comment