Rescue Protocol To Improve The Image Quality Of F-18-Fdg Pet/Ct Myocardial Metabolic Imaging

PurposeF-18-FDG PET myocardial metabolic imaging is used to estimate myocardial viability. However, poor image quality can affect the accurate quantification of viable myocardium. We assessed the feasibility of a rescue protocol that reinjected low-dose F-18-FDG with simultaneous 1 to 2 U of insulin injection and oral administration of 10 g of glucose to improve the image quality of F-18-FDG PET myocardial metabolic imaging. Patients and MethodsFifty-one consecutive patients with poor quality to uninterpretable F-18-FDG PET/CT myocardial metabolic images received the rescue protocol immediately after the initial image acquisition. The postrescue image acquisition was performed 1 hour later. The rescue image quality was compared with the initial image. The qualitative visual estimation of the images was graded as follows: grade 0, homogeneous, minimal uptake; grade 1, predominantly minimal or mild uptake; grade 2, moderate uptake; and grade 3, good uptake. The myocardium-to-blood pool activity ratio (M/B) was measured to assess the image quality quantitatively. ResultsThe grades of 0 to 3 were observed in 24 (47%), 27 (53%), 0 (0%), and 0 (0%) patients, respectively, for the initial imaging, and in 0 (0%), 3 (5.9%), 4 (7.8%), and 44 (86.3%) patients for the rescue imaging (P < 0.001). The rescue M/B was significantly higher than the initial M/B (3.4 +/- 1.4 vs 1.6 +/- 0.6, respectively; P < 0.001). ConclusionsThe rescue protocol successfully and rapidly improved the quality of myocardial F-18-FDG metabolic imaging.