Direct comparison between 2-dimensional and 3-dimensional PET acquisition modes for myocardial blood flow absolute quantification with O-15 water and N-13 ammonia.
BACKGROUND
Positron emission tomography scanners with retractable septa allow both 3-dimensional (3D) and 2-dimensional (2D) acquisition modes. The study aim was to directly compare 2D and 3D acquisition modes for the evaluation of absolute myocardial blood flow (MBF) over a wide range of flow values.


RESULTS
Instrumentation was used in 4 dogs to reduce the left circumflex artery lumen by greater than 75%. During infusion of adenosine, MBF was measured with both 2D and 3D dynamic acquisition and both oxygen 15 water and nitrogen 13 ammonia. Injected activities were 333 MBq and 111 MBq for 2D acquisition and 3D acquisition, respectively. Data were reconstructed by analytic methods, and MBF was assessed by use of an 18-segment model. MBF values ranged from 0.4 to 5.8 mL x g(-1) x min(-1) with O-15 water and from 0.3 to 3.9 mL x g(-1) x min(-1) with N-13 ammonia. No significant differences were observed in absolute MBF values obtained with the 2 acquisition modes, regardless of the flow tracer used. Two-dimensionally and three-dimensionally derived MBF values were significantly strongly correlated by use of both O-15 water (y = 0.98x + 0.18, r = 0.87, P < .001) and N-13 ammonia (y = 0.99x + 0.09, r = 0.95, P < .001).


CONCLUSIONS
Quantification of MBF in dogs with 3D positron emission tomography provides results similar to those obtained with the 2D technique, despite a lower activity being injected.
Department of Nuclear Medicine, Université Catholique de Louvain, Cliniques Universitaires St-Luc, Brussels, Belgium. veronique.roelants@imre.ucl.ac.be
Véronique
V
Roelants
Anne
A
Bol
Xavier
X
Bernard
Ann
A
Coppens
Jacques
J
Melin
Bernhard
B
Gerber
Jean-Louis
JL
Vanoverschelde
D000641:Ammonia; D000818:Animals; D001783:Blood Flow Velocity / Q000502:physiology*; D003326:Coronary Circulation / Q000502:physiology*; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000502:physiology*; D004285:Dogs; D009590:Nitrogen Radioisotopes; D010104:Oxygen Radioisotopes; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014867:Water
D009590:Nitrogen Radioisotopes; D010104:Oxygen Radioisotopes; D019275:Radiopharmaceuticals; D014867:Water; D000641:Ammonia