MRI: Introduction to MRI Flashcards
Biomedical imaging modality that involves:
Placing the body in a strong magnetic field to cause spin systems to precess by transmitting radio frequency energy to the body and receiving radio energy induced in the body
This is arguably the fastest growing imaging modality recently
MRI
Biomedical imaging modality that involves:
Transmission of ultrasonic waves toward the body and detection of reflected ultrasonic waves from the body
Ultrasound
Biomedical imaging modality that involves:
Injection of radiotracers in the bloodstream of the body and detection of gamma rays emitted from radiotracers within the body
Nuclear medicine (planar scintigraphy, SPECT, PET)
Biomedical imaging modality that involves:
Transmission of X-rays through the body and detection of X-rays on the opposite side of the body.
Radiographic imaging (e.g. X-ray, CT)
What does MRI stand for
Magnetic Resonance Imaging
What is the phenomena called when radio frequency energy is transmitted to the body
Magnetic resonance
Biomedical imaging modality/s that fall under the middle of the electromagnetic spectrum at around visible light
Optical imaging
Biomedical imaging modality/s that fall under radio waves (also close to microwaves)
Ultrasound and MRI
The electromagnetic spectrum in order from highest wavelength (low frequency) to lowest wavelength (high frequency)
Radio
Microwave
Infrared
Visible
Ultraviolet
X-ray
Gamma ray
The first beauty of biomedical imaging
Noninvasive (Ultrasound and MRI are completely noninvasive)
Biomedical imaging modality/s that fall under gamma rays
PET scan
Biomedical imaging modality/s that fall under X-rays
CT scan
Features that MRI has in comparison with other imaging modalities
High spatial resolution
High soft tissue contrast
Tomographic imaging
Scan along any direction
Noninvasive
Integration of different imaging modalities
SPECT, PET, Diffusion/Perfusion MRI, and fMRI are involved.
The last beauty of biomedical imaging
Physiology, Metabolism, and Function
These biomedical imaging modalities fall under projection imaging
X-ray and planar scintigraphy
The second beauty of biomedical imaging
Tomographic Imaging (CT, SPECT, PET, Ultrasound, and MRI involve tomographic imaging)
These biomedical imaging modalities expose you to radiation but are still noninvasive
X-ray, CT, SPECT, and PET
Two (2) reasons why protons are the main signal source of MRI
Protons are like tiny magnets and 70% of the body consists of H2O
Which particular protons are the main signal source of MRI
Hydrogens (H)
What is the main signal source of MRI?
Protons
MRI involves time sequencing of currents in radio frequency coil(s) and gradient coils.
The manipulation of these sequences provides various information of our body beyond anatomy
Pulse sequences
MRI involves ____ and ____ imaging
Physiological and functional imaging
Last Step of MR Image Aquisition
MR Image itself
Step 3 of MR Image Aquisition
K-space
Step 2 of MR Image Aquisition
Pulse sequence (then signal acquisition afterwards)
Step 1 of MR Image Aquisition
MRI
What spinning phenomena causes a proton to have a magnetic moment and act as a tiny magnet?
Spin angular momentum
Alternative nuclei that can be used for MRI
C, F, Na, O, P
Major hardware component of MRI that aids in imaging
A set of 3 gradient coils (X, Y, Z)
Major hardware component of MRI that aids in resonance
A radiofrequency transmitter and receiver
Major hardware component of MRI that is typically superconducting
Magnet (magnetic)
Spatially modulating the magnetic field strength to distinguish signals from different locations using gradient coils
Imaging
Transmitting RF energy through the subject via RF coil, turning of transmitter, and receiving RF signals emitted by the subject using the same or another RF coil
Resonance
Putting a subject in a strong magnetic field generated by the main magnet
Magnetic
