imaging in inflammatory disorders

Question 1

how PET scans work

Answer 1

patient is given a radioactive tracer ( eg. FDG ) this is metabolised by the body, structures in the body that have the highest rate of metabolism will show up brightest on the scan.

Question 2

Ideal isotope for labelling

Answer 2

• half-life similar to length of examination
• gamma emitter
• easy to bind to pharmaceutical component
• easily accessable

Question 3

detection of gamma radiation i gamma camera

Answer 3

gamma radiation is emitted from the body and hits a scintillator, a computer then converts the information from the scintillator into a digital image

Question 4

detection of gamma rays in PET scan

Answer 4

detectors on opposite sides of a ring around the patient, rotates and detects gamma emmission, this info is converted to an image by a computer.

Question 5

detection of gamma rays in SPECT

Answer 5

CT version of nuclear medicine, gamma cameras rotate around patient, converted to image by computer.

Question 6

equivalent period of background radiation for head CT

Answer 6

1 year

Question 7

equivalent period of background radiation for chest CT

Answer 7

3.6 years

Question 8

equivalent period of background radiation for barium enema

Answer 8

3.2 years

Question 9

examples of where imaging used

Answer 9

imaging is used in the diagnosis and monitory of progression and treatment of conditions such as:

• rheumatoid arthritis ( inflammation of joints caused by autoimmunity)
• aortitis
• ulcerative colitis (inflammation of inner lining of colon causing ulcers)