2: Modalities

Question 1

What is CR

Answer 1

Computed radiography: uses traditional X-ray cassettes that need to be manually put into a machine to be processed.

Question 2

What is DDR

Answer 2

Direct Digital Radiography: uses a detector linked to the X-ray system

Question 3

PACS

Answer 3

Picture archiving and communication systems (database of all X-rays)

Question 4

NIMIS

Answer 4

National PACS

Question 5

DEXA

Answer 5

Dual energy xray absorption

Question 6

Contrast media used for X-rays

Answer 6

Barium or iodine

Question 7

Contrast media used in MRI

Answer 7

Gadolinium

Question 8

CT

Answer 8

Computed tomography

Question 9

MRI

Answer 9

Magnetic resonance imaging

Question 10

How does MRI work

Answer 10

Uses radiofrequency energy
Protons in h20 molecules align in a magnetic field
RF energy flips the spin
When you turn off the gradient they flip back
Give off a signal called an echo
Echo converted into an image

Question 11

3 gradient fields

Answer 11

Static magnetic
Acoustic
Radiofrequency gradient fields

Question 12

US

Answer 12

Ultrasound

Question 13

How does ultrasound work

Answer 13

Sound waves are reflected back to the transducer by boundaries between tissues in the path of the beam.
Electrical signal generated when these echoes hit the transducer -image generated.

Question 14

NM

Answer 14

Nuclear medicine

Question 15

PET

Answer 15

Position emission tomography

Question 16

How does PET work

Answer 16

FDG is injected to discriminate benign from malignant tissues accurately (malignant tissues exhibit increased rates of glucose metabolism)