College aantekeningen

Preclinical imaging notes - 1st year Master - biomedical sciences

1 keer verkocht

Instelling
Universiteit Antwerpen (UA)

Notes on the course of preclinical imaging with a focus on neurology. The notes cover all the physical aspects of MRI, contrast agents, relaxation times etc. From lectures of Prof. Marleen Verhoye

[Meer zien]

Voorbeeld 4 van de 121 pagina's

Bekijk voorbeeld

Geupload op 9 maart 2021
Aantal pagina's 121
Geschreven in 2020/2021
Type College aantekeningen
Docent(en) Prof. marleen verhoye
Bevat Lectures from prof. marleen verhoye

mri
perfusion bolus tracking
contrast agent
phase encoding
frequency encoding
fmri
bold
arterial spin labelling
magnetization transfer
spin echo
gradient echo
magn
t1
t2
t2
magnetic resonance imaging

€11,49

In winkelwagen

Opslaan

100% tevredenheidsgarantie
Direct beschikbaar na je betaling
Lees online óf als PDF
Geen vaste maandelijkse kosten

PRE-CLINICAL IMAGING
WITH FOCUS ON
NEUROLOGY

, LECTURE 1 – MRI CONTRAST PRINCIPLES

Common imaging modalities:

 Projection X-ray = (electromagnetic)

 Computed Tomography (CT) = (electromagnetic)

 Ultrasound = (sound waves)

 Positron Emission Tomography (PET) = (nuclear)

 Single Photon Emission Tomography (SPET) = (nuclear)

 Magnetic Resonance Imaging (MRI) = (magnetic)

MRI uses radio-waves with a longer wavelength and thus a lower amount of

energy → not enough energy to cause change in atoms - Ultrasound is the only

method of imaging that uses sound waves (in the range of MHz) when all other

methods use electromagnetic waves → this method is fast and simple, it is the

first method to be used in the emergency unit when a person has complains to

have a quick look at the situation ➔ MRI and ultrasound have no health

consequences and can be performed as many times as necessary. This is in

,contrast to CT, PET and SPECT where there is the risk of ionization = major

advantage of MRI

MRI scans work as an imaging method due to unique composition of the human

body. We are comprised entirely of cells which all contain water – principally

made of H-ions.

The magnet embedded within the MRI scanner act on these positively charged

hydrogen ions and cause them to spin in an identical manner.

By varying strength and direction of this magnetic field, we can change the

direction of spin of the protons, enabling us to build layers of details.

When the magnet is switched off, the protons will gradually return to their

original state in a process known as precession. Fundamentally, the different

tissue types within the body will return at different rates and this is what

allows us to visualise and differentiate between the different tissues.

, As hydrogen atoms are electrically charged, they can be considered as little

magnets with north and south poles. This is what makes the hydrogen protons

susceptible to external magnetic field.

Each proton rotates 360 degrees around its own axis and has a positive and

negative pole.

!!! Each proton spins with a certain speed – LARMOR FREQUENCY. Because of

its spin, the proton continually changes phase (each phase is a snapshot).

When hydrogen protons enter strong
Nucleus of Gyromagnetic
external magnetic field, most protons will

align themselves parallel to the strong
particle ratio in

MHz/Tesla
1H 42.58
Electron -27,204
13C 10.71

Dit zijn jouw voordelen als je samenvattingen koopt bij Stuvia:

Bewezen kwaliteit door reviews

Studenten hebben al meer dan 850.000 samenvattingen beoordeeld. Zo weet jij zeker dat je de beste keuze maakt!

In een paar klikken geregeld

Geen gedoe — betaal gewoon eenmalig met iDeal, Bancontact of creditcard en je bent klaar. Geen abonnement nodig.

Focus op de essentie

Studenten maken samenvattingen voor studenten. Dat betekent: actuele inhoud waar jij écht wat aan hebt. Geen overbodige details!

Veelgestelde vragen

Wat krijg ik als ik dit document koop?

Je krijgt een PDF, die direct beschikbaar is na je aankoop. Het gekochte document is altijd, overal en oneindig toegankelijk via je profiel.

Tevredenheidsgarantie: hoe werkt dat?

Onze tevredenheidsgarantie zorgt ervoor dat je altijd een studiedocument vindt dat goed bij je past. Je vult een formulier in en onze klantenservice regelt de rest.