Magnetic Resonance Imaging (MRI)

What is Lorentz force?

It is a force perpendicular to the velocity and magentic field, depending on the direction of the particle travel- does not affect the particle kinetic energy only its trayectory

*** what needs to be known in refrence to MRI: The limit of Teslas for a safe MRI machine is 3, although 3 tends to be more for research—50T is enough otbreak material. Using his equation below, the lorentz force (F), the particle charge (q) and the velocity of the particles (v) can be used to find the magnetic field power in teslas (B).

How does an MRI work?

What are some MRI safety concerns?

• max magnetic field someone can be subject to is 40mT typically

• Giant magent, so metallic components cannot be brought near or into it

• We absrob EM waves, hence temperature can increase -careful with heat increase— levels controlled by SAR limits

• Caustrphobic people- migth be better to cover faces/heads

What are gradients and how can they be sued to better the image recieved?

They egenrate slight alterations in the waves/energy coming back from each point so that the images are clearer and more 3D

What are more coils or antennas for?

For better imaging in specific areas, the coils/antennas help in recieving the reflected signal as close as possible in rder to achieve a better imahge

What are MRI sequences

Different programs that aid in viewing specific areas