Quantitative assessment of regional myocardial blood flow using oxygen-15-labelled water and positron emission tomography: a multicentre evaluation in Japan

Recently, a method has been proposed for the quantitative measurement of re gional myocardial blood Flow (MBF) using oxygen-15-labelled water and posit ron emission tomography (PET), A multicentre project was organized with the intention of evaluating the accuracy of this method, particularly as a mul ticentre clinical investigative tool. Each of seven institutions performed PET studies on more than five normal volunteers following a specified proto col. The PET study included a tr ans mission scan, a O-15-carbon monoxide s tatic scan and a O-15-water dynamic scant thereby yielding MBF values which should have been independent of the spatial resolution of the PET scanner employed. Fifty-three subjects (aged 20-63 years, mean+/-SD 36+/-12 years) were studied at rest, and 31 of these subjects were also studied after dipy ridamole in five institutions, inter-institution consistency and intra-subj ect variation in MBF values were then evaluated. MBF averaged for all subje cts was 0.93+/-0.34 ml min(-1) g(-1) at rest and 3.40+/-1.73 ml min(-1) g(- 1) after the administration of dipyridamole, and the flow reserve (defined as the ratio of the two MBF values) was 3.82+/-2.12 these values are consis tent with previous reports, Resting MBF values were significantly correlate d with the heart rate-blood pressure product (RPP) (y=0.31+6.56E(-5)x, P<0. 010), and RPP was in resting MBF observed in all institutions was well expl ained by the age-dependent RPP, No significant difference was observed in r esting MBF among the institutions. Except in one institution, no significan t difference was seen in dipyridamole MBF or mpocnrdial flow reserve, No si gnificnnt difference was found among the myocardial segments. Regional vari ation was reasonably small in five institutions, but was not acceptable in two institutions. which was attributed to the scanner performance, These ob servations suggest that the O-15-water PET technique is useful for a multic entre clinical study if the PET scanner can provide time-activity data with good count statistics.