Imaging with Positron Emission Tomography/ Computed Tomography ( PET/CT)

1. Imaging with Positron Emission Tomography/ Computed Tomography (PET/CT) Lisa Rhoden (RT)(R) B.S. CNMT

2. PET • PET permits investigation and comparison of events occurring at the molecular and cellular level. • This data is not attainable by other modalities. • PET is especially useful in the detection of cancer, coronary heart disease, and brain disease. • The basis of PET is the positron • The positron is a positively charged beta particle emitted from neutron-poor radionuclides. • The result of this emission are annihilation photons that create 2 gamma rays of exactly 511 keV each, at 180 degrees to each other.

3. Positron Decay • Annihilation - two photons 511 keV - Positronium 180o + 511 keV For more on Positron Decay click

4. PET/CT vs. PET • The ability to have the CT localization makes interpretations more accurate • PET/CT has advantages to the patient in making the acquisition time shorter • There is more accurate attenuation correction with PET/CT PET/CT Machine

5. Protocol:Dose Receiving • Upon receiving a dose shipment from the pharmacy, the technologist must check it in • This includes measuring the radioactivity in mR at the surface of the box and at one meter away. • All measurements are recorded and kept

6. Protocol: Patient Prep (at UAMS) • Patient is to be held NPO (with the exception of water) a minimum of six hours prior to injection time • No insulin or Dextrose-5 should be given to the patient for a minimum of six hours prior to injection • The patient may receive 5-10 mg of Valium before the injection is given • The patient should be made comfortable and relaxed Did the patient follow the prep correctly? YES NO

7. Protocol: Blood Glucose Level • A blood glucose level will be obtained prior to injection and recorded • Optimum blood glucose level is below 150 mg/dL Select the patient’s blood glucose level Below 150 mg/dL Above 150 mg/dL

8. Next: Assay the Dose • The tech will then do background counts and a wipe test • Next the dose will be assayed, or measured for radioactivity in the dose calibrator

9. Protocol: Isotope Injection An IV will be started and used to administer the radioactive tracer Patient will wait 2-3 hours to allow the isotope to be taken into the cells

10. Protocol Cont. • Patient will drink approximately 300 cc of contrast containing Omnipaque (iohexol) 300 mgI/ml • Remove metallic objects • Empty bladder

11. Protocol Cont. • Position for scanning • Patient position will be determined based on area being scanned

12. Data Acquisition and Processing

13. Colorectal Carcinoma CT PET FUSED

14. Breast Cancer CT PET Fused

15. Review Basic PET Process Tracer injection & data acquisition Isotope production (cyclotron) Data synthesis Tracer labeling (radiochemistry) Image reconstruction Interpretation

16. Thank you for your time Questions? Want more? For questions or concerns regarding PET/CT scanning and procedures please send me an email by clicking the button below If you would like more information on this topic and other related topics, please go to the website by clicking the button below