Abstract: SA-PO051
Renal PET/CT-Rubidium-82 (Rb-82) Is a Precise and Reliable Method for Determination of Renal Blood Flow (RBF)
Session Information
- Engineering-Based Approaches to Problems in Nephrology
November 09, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Bioengineering
- 300 Bioengineering
Authors
- Langaa, Stine, Holstebro Hospital, Holstebro, Denmark
- Lauridsen, Thomas Guldager, Holstebro Hospital, Holstebro, Denmark
- Fynbo, Claire A., Herning Hospital, Herning, Denmark
- Theil, Jorn, Herning Hospital, Herning, Denmark
- Bech, Jesper N., Holstebro Hospital, Holstebro, Denmark
Background
Changes in RBF may play a pathophysiological role in hypertension and kidney disease; however, RBF determination in humans has proven difficult.
In a previous study, we demonstrated that RBF estimation based on PET/CT and Rb-82 is feasible and established that RBF can be determined based on a single PET/CT-Rb-82 scan, hereby minimizing radiation exposure associated with the method. We also found an intra-assay coefficient of variation of approximately 5.5% for both kidneys which indicates that the method is precise.
The aim of this study is to test the reliability of renal PET/CT-Rb-82 for RBF estimation.
Methods
Ten healthy subjects underwent three dynamic PET/CT-Rb-82 scans spread over two days. Rb-82 was given as bolus injections. On day 1, a single 8 min dynamic scan was performed. On day 2, an 8 min dynamic scan was performed before and after RBF was stimulated by a two-hour long infusion of an amino acid-solution. Time activity curves of arterial activity and renal uptake were recorded, and a 1-tissue compartment model was used for Rb-82 renal clearance estimation using PMOD® software. The clearance constant K1 in the model represents RBF. The day-to-day variation was calculated as the difference between the unstimulated K1-values on day 1 and day 2. K1-values determined before and after RBF stimulation on day 2 were compared.
Results
The mean unstimulated K1 value was 1.80 ± 0.17 ml/min/g for the right kidney and 1.78 ± 0.19 ml/min/g for the left kidney. The mean stimulated K1 value was 1.97 ± 0.17 ml/min/g for the right kidney and 1.95 ± 0.19 ml/min/g for the left kidney. There was no significant difference between the right and the left kidney for either the unstimulated or the stimulated K1 values. The day-to-day variation was 5.2% for the right kidney and 5.3% for the left kidney. For both kidneys, K1-values determined after RBF stimulation were significantly higher than K1-values determined before stimulation.
Conclusion
The approximate 5% day-to-day variation was acceptably low. For both kidneys, a significant increase in RBF was detected after application of a well-documented RBF stimulus. In conclusion, our preliminary results indicate that renal PET/CT-Rb-82 is a precise and reliable method for RBF determination.
Funding
- Government Support - Non-U.S.