nm 4103 section ii instruments & radiopharmaceutical production
TRANSCRIPT
NM 4103Section II NM 4103
Section II
Instruments & Radiopharmaceutica
l Production
Instruments & Radiopharmaceutica
l Production
Gas Filled DetectorsGas Filled Detectors
Ionization chambers Operate on 50-300 V Dose Calibrator
Geiger-Muller counters Operate around 1000V
Ionization chambers Operate on 50-300 V Dose Calibrator
Geiger-Muller counters Operate around 1000V
Dose CalibratorDose Calibrator
Sealed chamber
Filled with argon & halogen Operating voltage around 150 V
Used for measuring activity of radiopharmaceuticals
Sealed chamber
Filled with argon & halogen Operating voltage around 150 V
Used for measuring activity of radiopharmaceuticals
Geiger-Muller CounterGeiger-Muller Counter
Used to detect beta and gamma radiations
Usually operates as a ratemeter Readings can be given in:
uR/hour mR / hour R / hour Cpm
Used for area survey (contamination)Calibrated annually with 226Ra or 137Cs
Used to detect beta and gamma radiations
Usually operates as a ratemeter Readings can be given in:
uR/hour mR / hour R / hour Cpm
Used for area survey (contamination)Calibrated annually with 226Ra or 137Cs
Scintillation Detectors
Scintillation Detectors
Well counter Thyroid probe Gamma camera
Gamma rays interact in the sodium iodide detector and light photons are emitted.
Well counter Thyroid probe Gamma camera
Gamma rays interact in the sodium iodide detector and light photons are emitted.
DetectorsDetectors
Sodium iodide crystals (most common)
Light generated in the crystal is then directed at the PM tube
Sodium iodide crystals (most common)
Light generated in the crystal is then directed at the PM tube
CollimatorsCollimators
Covers the sodium iodide detector Purpose is to limit the field of view
Made of lead Holes of different shapes and sizes
Increased number of holes = increased sensitivity (but loss of resolution)
Covers the sodium iodide detector Purpose is to limit the field of view
Made of lead Holes of different shapes and sizes
Increased number of holes = increased sensitivity (but loss of resolution)
Thyroid Probe Collimator
Thyroid Probe Collimator
Single bore Cylinder shaped One PM tube
Single bore Cylinder shaped One PM tube
Scintillation Camera Collimators
Scintillation Camera Collimators
Parallel : most common Diverging : organ larger than the size of the detector
Pinhole : small organs/areas (thyroid)
Converging : organ smaller than the size of the detector
Parallel : most common Diverging : organ larger than the size of the detector
Pinhole : small organs/areas (thyroid)
Converging : organ smaller than the size of the detector
Parallel-hole Collimator
Parallel-hole Collimator
Can be high-resolution, all purpose or high-sensitivity
Size and number of holes the same, change thickness
Can be high-resolution, all purpose or high-sensitivity
Size and number of holes the same, change thickness
Photomultiplier TubePhotomultiplier Tube
Fixed to the sodium iodide crystal
Photocathode / series of dynodes / anode (all in a vacuum glass tube)
Fixed to the sodium iodide crystal
Photocathode / series of dynodes / anode (all in a vacuum glass tube)
CyclotronCyclotron
Charged particles are accelerated in circular paths under vacuum by an electromagnetic field
Radionuclides are usually neutron deficient and decay by + emission or electron capture
Examples: Gallium-67 Iodine-67 Indium-111 Thallium-201 PET radiopharmaceuticals (Carbon-11,Nitrogen-13,Oxygen-15,Fluorine-18)
Charged particles are accelerated in circular paths under vacuum by an electromagnetic field
Radionuclides are usually neutron deficient and decay by + emission or electron capture
Examples: Gallium-67 Iodine-67 Indium-111 Thallium-201 PET radiopharmaceuticals (Carbon-11,Nitrogen-13,Oxygen-15,Fluorine-18)
ReactorReactor
Constructed with fuel rods that undergo spontaneous fission
Radionuclides are usually neutron rich and decay by - emission
Examples: Iodine-131 Molybemum-99 Xenon-133 Cesium-137
Constructed with fuel rods that undergo spontaneous fission
Radionuclides are usually neutron rich and decay by - emission
Examples: Iodine-131 Molybemum-99 Xenon-133 Cesium-137
Specific ActivitySpecific Activity
Radioactivity per unit mass Expressed in mCi / mg Accurate only at the date and time of calibration
Radioactivity per unit mass Expressed in mCi / mg Accurate only at the date and time of calibration
ConcentrationConcentration
Radioactivity per unit volume Expressed in mCi / ml Accurate only at the date and time of calibration
Radioactivity per unit volume Expressed in mCi / ml Accurate only at the date and time of calibration
GeneratorGenerator
Long lived parent radionuclide continually decays to a shorter lived daughter radionuclide
Chemical properties must be different, so they can be easily separated from one another
Generator must be sterile and pyrogen-free
Long lived parent radionuclide continually decays to a shorter lived daughter radionuclide
Chemical properties must be different, so they can be easily separated from one another
Generator must be sterile and pyrogen-free
Parent/Daughter relationship
Parent/Daughter relationship
Daughter grows as a result of the decay of the parent until equilibrium is reached
Daughter activity is eluted, leaving the parent on the column
After elution, the daughter activity starts to grow again
Daughter grows as a result of the decay of the parent until equilibrium is reached
Daughter activity is eluted, leaving the parent on the column
After elution, the daughter activity starts to grow again
99Mo - 99mTc Generator99Mo - 99mTc Generator
99Mo has a half-life of 66 hours & decays by - emission
99mTc has a half-life of 6 hours & decays by isomeric transition
Liquid or solid column
99Mo has a half-life of 66 hours & decays by - emission
99mTc has a half-life of 6 hours & decays by isomeric transition
Liquid or solid column
Solid column generatorSolid column generator
Alumina oxide on a column (encased in lead)
99mTc builds up until the maximum activity is reached (usually 4 half-lives)
Wet or dry column generators Dry : after elution, the leftover saline in the column is drawn out with vial
Alumina oxide on a column (encased in lead)
99mTc builds up until the maximum activity is reached (usually 4 half-lives)
Wet or dry column generators Dry : after elution, the leftover saline in the column is drawn out with vial
~QC testing ~ 99Mo Breakthrough~QC testing ~
99Mo Breakthrough Radionuclide purity Molybdemum contamination in the elution
Limit: 0.15 uCi of 99Mo / 1 mCi of 99mTc
Radionuclide purity Molybdemum contamination in the elution
Limit: 0.15 uCi of 99Mo / 1 mCi of 99mTc
~QC testing~Aluminum Breakthrough
~QC testing~Aluminum Breakthrough
Aluminum contamination Limit
10 ug Aluminum ion / ml 99mTc eluate
Aluminum interferes with tagging sulfur colloid and RBC’s
Aluminum contamination Limit
10 ug Aluminum ion / ml 99mTc eluate
Aluminum interferes with tagging sulfur colloid and RBC’s
~QC testing~pH
~QC testing~pH
Should be between 4.5 and 7.5 Should be between 4.5 and 7.5