Dynamic SPET parameters of I-123-MIBG cardiac imaging

Early dynamic and late I-123-MIBG SPET studies were performed to investigat e several parameters used to distinguish the characteristics of various car diac disorders. Forty-six individuals (34 non-diabetic, 12 diabetic) with o r without heart disease were included in the study. Early dynamic and late static SPET images were acquired using a triple-headed gamma camera. After selecting mid-sections from vertical (VLA) and horizontal (HLA) long-axis i mages, regions of interest were created over the apex, whole heart and ante rior, inferior, septal and lateral walls of the heart. Various uptake ratio s at 3, 11 and 19 min and 4 h after injection (HU3, HU11, HU19, DUP) and cl earances (K-se: between HU3 and HU11; K-e: between HU11 and HU19; K-d: betw een HU19 and DUP) were calculated. There were significant differences among various cardiac pathologies on the delayed images. Cardiomyopathy patients showed the lowest uptake on the delayed images. When all segments in norma l patients and all involved segments in myocardial infarcted patients were compared, there was significantly lower uptake of MIBG in infarcted segment s at all time points. K-d showed the lowest value compared with K-se and K- e. In cardiomyopathy patients, K-se, K-e and K-d were significantly differe nt from each other. both K-se and K-e were significantly higher in cardiomy opathy patients than in normal patients. In conclusion, the results of this study are in line with published data and precise measurement of uptake an d clearance was possible when excluding background and blood pool activity. ((C) 1999 Lippincott Williams & Wilkins).