Quality control
From Radipedia
Radionuclide Purity
- Degree of contaminatin from other radionuclides
- Increase dose without contributing to image
- Should never contribute more than 10% of dose to patient
- Mo99 Breakthrough
- Performed with every elution
- Shield with Lead,740 and 780 keV of Mo will go through, 140 keV of Tc will not
- There are also chemical tests
- Limit of 0.15 uCi Mo99 per mCi Tc99m at time of administration
Radiochemical Purity
- How well the label worked
- Tested by thin layer chomatography
- Can identify free pertechnetate
Chemical Purity
- Al ion breakthrough
- Degrades image quality, interferes with labeling
- NRC limit 10ug per ml
- Measured on color paper strip
- Must also be Sterile and Apyrogenic
Dose Calibrator
- Ensures constancy
Uniformity Testing
- Makes sure counts are equal throughout the field of view
- Performed daily
- Flood by cobalt sheet with (extrinsic) and without (intrinsic) collimator
- Looks for cracked crystals or failed PMT
- Off Peak Image - can occur after daily uniformity test if Co used (keV 122) and not changed before a Tc study (140 keV), results in blur from scatter
Resolution Testing
- Performed daily
- Parallel lines
Center of Rotation
- Performed weekly
