NM 4103 Section II Instruments & Radiopharmaceutical Production

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