| Myocardial blood flow (MBF) and flow reserve (MFR) are important prognostic markers for patients with heart disease. By comparing patient scans with a database defining the lower limit of normal MBF or MFR, diagnosis may be improved. The clinical standard for flow measurement is nitrogen-13-ammonia ( 13NH3) positron emission tomography imaging, necessitating an expensive cyclotron. A cost-effective alternative is the generator-produced tracer rubidium-82 (82Rb). 82Rb is commonly used for relative MBF imaging; its accuracy for absolute MBF imaging has not been widely assessed. Tracer kinetic methods for quantifying MBF with 82Rb, including compartment and net retention models, were developed and validated versus 13NH 3 measurements. Normal population databases were created and used for patient evaluation. The results support MBF quantification with 82 Rb, and suggest that compartment modeling with 13NH 3 remains most precise for quantifying absolute flow, whereas the retention model is most accurate for detection and localization of abnormal MBF. |
