MRI 5 Flashcards
Repetition Time (TR)
The time interval between successive excitation pulses, usually expressed in seconds.
Echo Time (TE)
The time interval between an excitation pulse and data acquisition, usually expressed in milliseconds.
Static contrast
Contrast mechanisms that are sensitive to the type, number, relaxation properties, and local environment of spins (i.e. T1, T2, proton density).
T1-Weighted Images
Images that provide information about the relative T1 values of tissue; also known as T1 images.
T2-Weighted Image
Images that provide information about the relative T2 values of tissue; also known as T2 images.
T2*-Weighted Images
Images that provide information about the relative T2* values of tissue; also known as T2* images.
Chemical Shift Imaging
A technique for measuring the concentration of particular chemicals, based on subtle differences in the resonance of the protons they contain.
Magnetization Transfer
An MR imaging technique that uses an off-resonance excitation pulse to saturate the MR signal from large molecules; the subsequent influence of that pulse upon free protons in water indicates the concentration of those large molecules.
MRA
The creation of images of the vascular system using MRI.
Diffusion
The random motion of molecules through a medium over time.
Diffusion Weighting
The application of magnetic gradients to cause changes in the MR signal that are dependent on the amplitude and/or direction of diffusion.
Perfusion
Blood flow through tissue.
