Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
13 Cards in this Set
- Front
- Back
|
MRI stands for?
|
Magnetic
Resonance Imaging |
|
|
What is being imaged in MRI?
|
-Proton density
-T1 and T2 relaxation times |
|
|
What is being imaged in SPECT, PET?
|
Distribution of introduced radioisotopes.
|
|
|
What is being imaged in classical radiography?
|
Distribution of linear attenuation coefficient.
|
|
|
What is being imaged in ultrasonography?
|
-Distribution of acoustic impedance.
-Velocity of flow |
|
|
Name 6 advantages of MRI over other, "classical" imaging techniques.
|
-Neglibile side-effects
-True multiplanar imaging -High, unique contrasting of soft tissues -Ability of flow imaging w/o contrast agents -Simultaneous information about both anatomical and physiological information. -Less severe artefacts. |
|
|
What tissue properties determine the MRI image?
|
-Proton density
-T1 and T2 relaxation times -Macroscopic motion (flow of liquids) -Microscopic liquids (diffusion) |
|
|
What do T1 and T2 relaxation times depend on?
|
-Water content
-Mobility of molecules -Presence of large molecules -Presence of paramagnetic molecules -Temperature and magnetic field intensity |
|
|
What does echo 1 depend on?
What does echo 2 depend on? |
-Only on T2 and TR
-T1, T2, TR and TE |
|
|
The intensity of a tissue signal (brightness of an image) is?
|
-Proportional to proton density
-Proportional to T2 -Inversely proportional to T1 |
|
|
T1 relaxation does what?
T2 relaxation does what? |
-Restores NMR signal intensity
-Reduces NMR signal intensity |
|
|
FONAR?
|
Field fOcused Nuclear mAgnetic Resonance
|
|
|
Contrasting agents
Are what type of molecules? What effects to they have? How do areas of accumulated contrasting agents appear on T1 and T2 images? |
-Highly paramagnetic molecules
-Shorten relaxation times and enhance contrast -Brighter on T1 imgages -Darker on T2 images |
