Test 3 Intro to Nuclear Imaging

Question 1

What are the main types of anatomical imaging?

Answer 1

• MRI

- CT

Question 2

What does anatomical imaging do?

Answer 2

• provides information about morphology of tissues

- looking at bone structure, primary tumors

Question 3

computed tomography

Answer 3

• multiple xray exposure that are combined into a 3D image
• measure transmission of xray via radiodensity
• resolution: < 1mm
• fast acquisition
• cam be used with metallic implants
• radiation dose: about 3 yrs of background radiation
• relatively low costs
• good for hard tissue

Question 4

What is the difference of CT scan with and without contrast?

Answer 4

• without contrast: looking at hard tissue, gives high resolution, high radiodensity
• with contrast: can see embolism in arteries, etc

Question 5

magnetic resonance imaging

Answer 5

• uses powerful magnetic fields to measure elemental radiofrequency energy in a tissue
• measures nuclear spin energy in a tissue
• resolution: <1 mm
• takes about 40-60 min to obtain
• cost is twice as much at CT
• good for soft tissue

Question 6

nuclear imaging

Answer 6

• use of radioactive substances to diagnose a disease

- radiation source is internal

Question 7

SPECT

Answer 7

• Single Photon Emission Computed Tomography
• patient inject with radio-labeled probe -> cameras measure gamma rays emitted
• radiotracers are chelated to the targeted moiety
• resolution: 1cm
• radiation dose: 1-3 years of background radiation
• takes about 40 min
• cost is relatively low

Question 8

PET

Answer 8

• Positron Emission Tomography
  -uses positron
  patient injected by radiolabled probe
• resolution: 2mm
• radiation: 8 years of background radiation
• 30 min acquisition time
• cost is twice as much as CT

Question 9

What is attenuation?

Answer 9

the lower energy your photons is, the less it can transmit through your tissue

Question 10

half value layer

Answer 10

thickness of the material at which the intensity of radiation entering it is reduced by one half

Question 11

describe the relationship between photon keV and HVL

Answer 11

↑ photon keV = ↑ HVL

Question 12

(99m)Technetium Radionuclide

Answer 12

• keV: 140
• half life: 6 Hours
• modality: SPECT

Question 13

(18)Fluorine

Answer 13

• keV: 511
• half life: 109 Min
• modality: PET

Question 14

What is the energy for positrometers?

Answer 14

511 keV

Question 15

What are the three forms of imaging?

Answer 15

• anatomical imaging
• physiological imaging
• molecular imaging

Question 16

What can you see with anatomical imaging?

Answer 16

• bones
• tumors
• vasculature
• CT, MRI

Question 17

What can you see with physiological imaging?

Answer 17

• blood flow
• metabolism
• pH
• renal clearance
• cancer imaging
• perfusion
• SPECT, PET, CT, MRI

Question 18

What can you see with molecular imaging?

Answer 18

• receptor imaging (ex. checking for disease)
• drug kinetics (ex. measuring drug response, biodistribution)
• referred to as “biomarker imaging”
• MRI, SPECT, PET