Imaging in Inflammatory disorders and Infections

Question 1

what is molecular imaging

Answer 1

provides functional information

radionuclide imaging

positron emission tomography (PET)

Question 2

Radiography vs radionuclide imaging

Answer 2

Radiography - x-ray tube, patient, digital image capture, PACS

Radionuclide imaging - radiopharmaceutical, gamma rays, patient, lead collimator gamma camera, PACS

Question 3

Properties of an ideal isotope

Answer 3

Half-life similar to length of examination

gamma emitter, rather than a or B

energy of y rays should be 50-300 KeV

radionuclide should be readily available at hospital site

easily bound to pharmaceutical component

radiopharmaceutical should be simple to prepare

radiopharmaceutical should be eliminated in similar half-time to duration of examination

Question 4

What do radiopharmaceuticals do

Answer 4

used to diagnose certain medical problems or treat certain diseases.

may be given to the patient in several different ways.

eg. they may be given by mouth, given by injection, or placed into the eye or into the bladder.

Question 5

gamma camera process

Answer 5

1. nuclear energy - inside the radioactive nucleus
2. gamma electromagnetic energy - gamma ray has been emitted from the patient
3. light electromagnetic energy - the image crystal produces flashes of light
4. electrical energy - to display image

Question 6

Image quality production

Answer 6

radiation dose - limits

collimator - filter out stray gamma rays - reduce blurriness

metal objects- move

proximity of area of interest to camera

Question 7

What is single photon emission tomography (SPECT)

Answer 7

Ct version of nuclear medicine

gamma cameras rotate around area of interest

routinely used for brain and cardiac studies

can be applied to any site of interest in other studies

Question 8

What is positron emission tomography (PET)

Answer 8

molecular imaging

uses radionuclides that decay by positron emission - proton to neutron and positron

these can be used to image biologically interesting processes

can be used for absolute quantitation but requires arterial sampling

all scanners now PET CT

Question 9

Examples of inflammatory diseases

Answer 9

rheumatoid arthritis

aortitis

ulcerative colitis

Question 10

Risk and benefits to radiation

Answer 10

risks- ionising radiation, risk of inducing fatal cancer eg. CT abdomen & pelvis 1:1600

benefits - should always outweigh cost