Simultaneous evaluation of myocardial blood flow, cardiac function and lung water content using [15O]H2O and positron emission tomography.
OBJECTIVE
This study sought to evaluate an imaging approach using [15O]H2O and positron emission tomography (PET) for simultaneous assessment of myocardial perfusion, cardiac function and lung water content as a potential indicator of pulmonary oedema.


METHODS
Twenty-six subjects divided into two groups (group I, 13 patients with idiopathic dilated cardiomyopathy; group II, 13 healthy volunteers) underwent dynamic PET scanning after intravenous infusion of approximately 995 MBq [15O]H2O. In both groups, echocardiograms were performed after the PET studies. From the dynamic [15O]H2O data, lung water content (LWC) at equilibrium, myocardial blood flow (MBF), cardiac output (CO), stroke volume (SV) and stroke volume indexes (SVI) using the indicator dilution principle were determined.


RESULTS
LWC was 18% (p = 0.038) higher in patients than in controls. Global MBF did not differ significantly between the groups, but regional MBF values were significantly lower (p < 0.05) in the anterior and septal walls in the patient group. The results of the Passing-Bablok regression indicated the absence of a systematic difference between the two techniques. Bland-Altman analysis performed for each group (patients vs healthy controls) showed a non-significant bias (p > 0.1) of -0.02 +/- 0.82 vs -0.05 +/- 0.54 l/min (CO), -1.44 +/- 14.31 vs 1.70 +/- 10.56 ml/beat (SV) and 0.47 +/- 6.21 vs 0.30 +/- 5.02 ml/beat/m2 (SVI). The 95% limits of agreement were -1.62 to 1.59 vs -1.11 to 1.01 l/min (CO), -26.61 to 29.49 vs -22.39 to 18.99 ml/beat (SV) and -11.69 to 12.88 vs -9.53 to 10.14 ml/beat/m2 (SVI). Right ventricular CO was increased by 33% (p = 0.014) in the patient group as compared with normal controls.


CONCLUSIONS
Our results demonstrate that additional analysis of cardiac function and lung water content are feasible from the dynamic cardiac [15O]H2O PET studies acquired for myocardial perfusion. The parameters appear to work as expected. Further studies are warranted to elucidate the clinical value of these new parameters.
Naum
Alexandru
A
Turku PET Centre, Turku University Central Hospital, P.O. Box 52, 20521, Turku, Finland.
Tuunanen
Helena
H
Engblom
Erik
E
Oikonen
Vesa
V
Sipilä
Hannu
H
Iozzo
Patricia
P
Nuutila
Pirjo
P
Knuuti
Juhani
J
D001834:Body Water / Q000378:metabolism*; D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging* / Q000378:metabolism*; D003326:Coronary Circulation; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008168:Lung / Q000000981:diagnostic imaging / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010104:Oxygen Radioisotopes; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D014867:Water
D010104:Oxygen Radioisotopes; D019275:Radiopharmaceuticals; D014867:Water