An Analysis of 3 Common CardioGen-82 82Rb Infusion System Injection Methods and Their Impact on Clinical Volume and Image Counts.

UNLABELLED: In the wake of the Food and Drug Administration (FDA) recall, many clinics have had to reduce their examination volumes to meet the new generator volume usage requirements. This review tests 3 common infusion methods and how they affect patient dose, generator volume usage, image counts, and generator volume limits. METHODS: Three common configurations of the (82)Rb infusion system settings--standard 50-mL, volume-limiting, and bolus methods--were tested to determine how they affect patient dose, generator volume, and image counts. Each injection configuration was tested daily for the duration of 3 consecutive generators by injection into separate vials. Each injection configuration was also infused into a beaker and imaged to determine the impact of image counts for each method. The total estimated volumes for multiple examination and quality assurance clinical situations were simulated to observe the use of each method relative to the new FDA volume alert and expiration limits. RESULTS: Vial tests confirmed that the bolus method used the least amount of volume per infusion and stayed the most consistent throughout the life of the generator. The bolus method also produced a lower patient dose after approximately 10 d of use. The beaker tests in the scanner showed that the standard 50-mL method produced the greatest number of total counts for the flow and uptake images. On the basis of the estimated total volume simulations, the bolus method allowed for the most examinations over the life of the generator while staying within the new FDA limits. CONCLUSION: All 3 methods for augmenting the (82)Rb infusion system produced different outcomes for patient dose, image counts, and total generator volume use. The standard 50-mL method ensured the maximum amount of counts available for imaging throughout the life of the generator. The bolus method provided a consistent and predictable amount of volume use. The volume-limiting method fell somewhere in the middle of volume predictability and count preservation.

Comparison of occupational radiation exposure from myocardial perfusion imaging with Rb-82 PET and Tc-99m SPECT.

OBJECTIVE: Rubidium-82 (Rb-82) PET myocardial perfusion imaging (MPI) has superior diagnostic accuracy, at least similar prognostic value, and lower patient radiation exposure when compared with technetium-99m single-photon emission computed tomography (Tc-99m SPECT) MPI. The aim of this study was to compare occupational radiation exposure from the two modalities and show that improvements for the patient do not come at a cost to staff. MATERIALS AND METHODS: Electronic personal dosimeters were worn by staff involved in the administration and imaging of routine clinical Tc-99m SPECT and Rb-82 PET MPI, and during tracer production and QC. To estimate dose to the staff in the event of a medical emergency, a survey meter was placed in close contact with the patient during Rb-82 infusion and imaging, and immediately after administration for Tc-99m SPECT. RESULTS: Mean (SD) whole-body effective dose to staff during a single MPI procedure was 0.4 (0.4) µSv for Rb-82 PET (1110 MBq) and 3.3 (1.7) µSv for Tc-99m SPECT (350 MBq). Staff effective dose during tracer production and QC was low (<0.2 µSv/patient) and comparable between tracers. An additional effective dose was measured at close contact to the patient during, and immediately after, tracer administration, although this will not pose a significant radiation risk to staff with either technique as long as this is not routine practice. CONCLUSION: There is a significant reduction in effective dose during Rb-82 PET when compared with Tc-99m SPECT MPI because of the short half-life of Rb-82 and reduced patient contact.