Radiopharmaceuticals Flashcards
1
Q
What does SPECT stand for?
A
Single photon emission computed tomography; it is 3D gamma ray immaging
2
Q
PET - how does it work?
A
- Positron forms and annhylates with an electron - the mass gets converted to energy and 2 photons result at 180 degree angles
- PET is a 3D imaging of photons given off when a positron annihilates with an electron
3
Q
Why is PET better than SPECT and planar scintagraphy?
A
- immage gamma radiation of much higher energies
- Improved quantification of data and of counting statistics - making lesions more detectable and more reliable
- Radiopharmaceuticals used with PET have shorter half lives - meaning patients get to go home sooner
4
Q
Radiopharmaceuticals have no pharmacologic effect. Why?
A
They are used in tracer quantities
5
Q
Name 3 radionuclide production devices
A
- Nuclear reactors
- Charged particle accelererators
- Radionuclide generators
6
Q
How is 99mTcO4- radiopharamceutical made?
A
- Made using generator column chromatography
- Parent isotope, Mycobonium-99, decays to Technetium-99
- Tc-99 gets eluded with saline to become 99mTcO4- which is in solution
- To make other RaPh that use Tc99m in label - use drug as a powder and add to the 99mTcO4- solution and it will combine to make RaPh
7
Q
Which has the shorter half life:
- Mycobonium - 99 (parent)
- Technetium -99m (daughter)
A
- Tc-99m
8
Q
Two other names for the Gamma Camera
A
- Scintillation camera
- Anger camera
9
Q
99mTcO4- ⇒Thyroid Scintigraphy
A
- RaPh that acts like Iodine goes to the zygomatic salivary gland and the thyroid
- Hyperthyroid, euthyroid, and hypothyroid is based on the thyroid/salivary ratio
- Can also detect:
- Hyperplasia - usually more one side than the other
- Multinodular Adenoma - looks like string of pearls
- Carcinoma - bilateral, metastasis can be seen
10
Q
99mTc Sulfur Colloid - Liver Scintigraphy
A
- Normal = well demarcated liver shape, sometimes more color on one side than the other
- Liver metastasis - 4 hallmakrs of cancer:
- Irregular borders
- Abnormal morphology
- Heterogenous uptake of pharmaceutical
- Photopenic void = no radioactivity = lesions
- Pseudotumor pattern of cirrhosis
- Looks just like cancer - need to take a biopsy to confirm dx
11
Q
Advantages of dynamic renal scintigraphy
A
- can quantify individual kidney function
- Can detect renal dysfunction before an increase in BUN can be detected
12
Q
99mTc - DTPA Renal Scintigraphy
A
- Provides a series of images of kidneys over a period of time to detect GFR - GFR scan
- Normal GFR is >3.0 mL/min/kig
- In renal failure, there is poor renal uptake of the RaPh and prolonged blood pool activity
13
Q
99mTc - DMSA Renal Morphology Imaging
A
- Used to evaluate size, shape, and location of kidneys
- Used to evaluate for acute pyelonephritis
- Used to determine the distribution of functional renal mass
- Uptake of the RaPh by the renal cortex
14
Q
99mTc - MDP (methylene diphosphate) Canine Bone Scan
A
- bone is dynamic, constantly remodelling
- Normally in equilirbium between osteoclastic and osteoblastic activity - cacner can disrupt this equilibrium
- Normal to see action at the ends ofl ong bones
15
Q
QuadraMetTM =
A
153Sm - EDTMP