title: Quantitation of the regional blood flow in the interventricular septum using positron emission tomography and nitrogen-13 ammonia.
abstract: The purpose of the present study was to evaluate the effect of spillover of activity from the right ventricle (RV) on quantitation of the regional myocardial blood flow in the septum. Thirty-one healthy volunteers, 31 patients with ischemic heart disease, 7 patients with severe congestive heart failure, and 6 heart transplant patients underwent positron emission tomography (PET) with nitrogen-13 ammonia. Quantitation of the regional myocardial blood flow in the septum was performed using both a conventional two-compartment model and a previously validated two-compartment model taking RV spillover into account. Unaccounted RV spillover resulted in significant underestimation of the regional myocardial blood flow in the septum. The amount of underestimation was primarily dependent on the magnitude of spillover and the dispersion between the right and the left ventricular input functions. In healthy volunteers, the flow error was small but significant: on average 6% (range 5%-29%, P<0.00001), compared with 27% (range 0%-88%, P<0.002) in the group of patients with severe congestive heart failure, who had the most considerable amount of RV spillover. In the group of patients with ischemic heart disease and the group of heart transplant patients the flow errors were 10% (range 0%-55%, P<0.00001) and 6% (range 1%-19%, P<0.01), respectively. It is concluded that flow quantitation in the septum is significantly affected by RV spillover, resulting in a considerable underestimation of the septal blood flow unless correction is performed.
authors.affiliation: Department of Cardiology, The Heart Center, Rigshospitalet, Juliane Mariesvej 24, 2100 Copenhagen, Denmark. jhove@nru.dk
authors.forename: Jens D
authors.initials: JD
authors.lastname: Hove
authors.forename: Sanjiv S
authors.initials: SS
authors.lastname: Gambhir
authors.forename: Klaus F
authors.initials: KF
authors.lastname: Kofoed
authors.forename: Jacob
authors.initials: J
authors.lastname: Freiberg
authors.forename: Henning
authors.initials: H
authors.lastname: Kelbaek
mesh_terms: D000641:Ammonia; D003326:Coronary Circulation; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000503:physiopathology; D006346:Heart Septum / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016027:Heart Transplantation / Q000000981:diagnostic imaging; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D008297:Male; D008955:Models, Cardiovascular; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging / Q000503:physiopathology; D009590:Nitrogen Radioisotopes; D019275:Radiopharmaceuticals; D014055:Tomography, Emission-Computed / Q000379:methods; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000503:physiopathology; D018497:Ventricular Dysfunction, Right / Q000000981:diagnostic imaging* / Q000503:physiopathology
chemical_list: D009590:Nitrogen Radioisotopes; D019275:Radiopharmaceuticals; D000641:Ammonia