MRI

Question 1

Define angular momentum, precession, and larmour frequency

Answer 1

Question 2

What is gyromagnetic ratio? For hydrogen?

Answer 2

Question 3

Correctly label the regions of the EM spectrum

Answer 3

Question 4

Define NMV. How does field strength affect it?

Answer 4

Question 5

Define flip angle

Answer 5

Question 6

Define phase

Answer 6

Question 7

Define the basics of MR signal generation and FID

Answer 7

Question 8

Define relaxation, recovery and decay

Answer 8

Question 9

Define T1 recovery

Answer 9

Question 10

Define T2 decay

Answer 10

Question 11

What causes signal / voltage induction?

Answer 11

Presence of COHERENT MAGNETIZATION IN TRANSVERSE PLANE

Question 12

Define TR and TE

Answer 12

Question 13

Detail susceptibility. What are the different groups of materials based on susceptibility?

Answer 13

Question 14

What does chemical shift refer to?

Answer 14

Question 15

Detail safety concerns: RF

Answer 15

Question 16

Detail safety concerns: Gradient magnetic field

Answer 16

Question 17

Detail safety concerns: Main magnetic field

Answer 17

Question 18

Detail the safety concerns related to : quench, fringe fields, and implants

Answer 18

Question 19

Detail permanent magnets

Answer 19

Question 20

Detail solenoid magnets

Answer 20

Question 21

Describe differences between open and closed bore systems

Answer 21

Question 22

Detail differences between volume and surface (inc subtypes) coils

Answer 22

Question 23

Detail features of MRI shielding

Answer 23

Question 24

Detail features of shimming

Answer 24

Question 25

Detail components of gradient system

Answer 25

Question 26

Detail the approximate location of key components of an MRI unit

Answer 26

Question 27

Which three characteristics of tissues are most importantn to determine T1 and T2 relaxation times?

Answer 27

Question 28

How do T1 recovery compare between fat and water?

Answer 28

Question 29

How do T2 decay times compare between fat and water?

Answer 29

Question 30

Describe how T1 contrast is produced and how fat and water behave

Answer 30

Question 31

Describe how T2 contrast is produced, and behaviour of fat and water. REMEMBER -> FAT DOESNT ENTIRELY MAKE SENSE!

Answer 31

Question 32

Destribe how proton density contrast is produced

Answer 32

Question 33

Difference in T1 and T2 times in brain tissues

Answer 33

Question 34

List factors resultingin intrinsic and extrinsic contrast in MRI studies

Answer 34

Question 35

Describe T1 weighting

Answer 35

Question 36

Describe PD weighting

Answer 36

Question 37

Detail mechanism of T2* decay

Answer 37

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Question 38

Define saturation

Answer 38

Question 39

Describe how spin echo works

Answer 39

Question 40

Describe sequences created with SINGLE REPHASING PULSE spin echo

Answer 40

Question 41

Describe sequences produced BY TWO REPHASING PULSE spin echo

Answer 41

Question 42

Describe basics of GRADIENT ECHO including advantages and disadvantages

Answer 42

Question 43

Detail how weighting is achieved in GRE sequences

Answer 43

Question 44

Complete the table: Spin vs gradient echo

Answer 44

Question 45

Detail role of gradients, and specifically SLICE SELECTION

Answer 45

Question 46

Detail frequency encoding gradient

Answer 46

Question 47

Complete the table! Slice select, freq and phase encoding gradients….

Answer 47

Question 48

Using the diagram, detail the TIMING of the different spatial encoding gradients

Answer 48

Question 49

Detail NSA / NEX

Answer 49

Question 50

Detail SNR. List 7 factors that affect it!

Answer 50

Question 51

Briefly describe FOV

Answer 51

Question 52

Detail role of SLICE GAP

Answer 52

Question 53

Detail 3 factors affecting SPATIAL RESOLUTION

Answer 53

Question 54

Detail 3 factors affecting scan time

Answer 54

Question 55

Detail features of Turbo spin echo

Answer 55

Question 56

What effect does increased turbo factor have on image production?

Answer 56

Question 57

Detail how weighting is achieved in TSE. What is TSE predominantly used for? Pros and cons

Answer 57

Question 58

Detail FLAIR sequence

Answer 58

Question 59

Detail STIR sequence

Answer 59

Question 60

Detail inversion recovery (general)

Answer 60

Question 61

Describe fat saturation

Answer 61

Question 62

Detail TOF phenomenon in SE -> What three factors does it depend on?

Answer 62

Question 63

Describe TOF in GRE images

Answer 63

Question 64

Detail TOF MRA

Answer 64

Question 65

Detail Phase contrast MRA

Answer 65

Question 66

What are MR myelographic sequences? THE MAIN ONE??

Answer 66

Question 67

Detail DWI / ADC

Answer 67

Question 68

Describe how MR agents (particularly GAD) work

Answer 68

Question 69

Dose of GAD

Answer 69

Question 70

Risks associated with GAD

Answer 70

Question 71

GAD AGENTS TABLE

Remember 2 safe ones and the one we use?

Answer 71

Safe ones: Gadoxetate, Gadobenate

We use: Gadobutrol