FROM PROTONS TO IMAGES Flashcards
What is the simplest atom?
hydrogen atom
What is the law of thermodynamics?
Higher energy states are less stable and that systems tend to change to their lower energy “equilibrium” conditions
What is the difference between the number of spins in the high and low-energy states?
longitudinal magnetization
The rate at which a material approaches equilibrium is determined by a time constant known as?
T1
The approach to equilibrium along the z-axis is known as what?
longitudinal relaxation
The t1 of body tissues ranges from about?
0.1-4.0 secs
T1 depends strongly on the ________–
mobility of protons on their temperature
It is the tendency of an object, once moving, to continue moving in the same direction
Momentum
It is the tendency of a spinning object to continue to spin about the same axis of rotation
angular momentum
The frequency at which the nuclei precess in a given magnetic field is known as what?
Larmor frequency
In a magnetic field of 1.0 T, the protons process at ________
42.58 MHz
What are the disadvantages of permanent magnets?
very heavy
limited to field intensity
What is another name for supplemental magnets/
resistive magnets
what is the unit for external magnetic field or magnetic field?
Bo
This is the overall alignment of a hydrogen atom
net magnetization
