[en] The myocardial blood flow (MBF) was measured with PET and the ¹⁵O steady-state method using a continuous infusion of H₂¹⁵O in 8 normal volunteers. The intra-vascular radioactivities were corrected by blood volume measured with a single inhalation of C¹⁵O. The MBF values were obtained both invasively and non-invasively. As the ¹⁵O steady-state method is susceptible to a partial volume effect due to a relatively thin myocardial wall thickness and wall motion, the MBF values were corrected for the partial volume effect by tissue fraction measured with transmission scan. The MBF values obtained non-invasively were 90.7±20.6, 65.1±21.6 and 104.4±44.5 ml/min/ml in the septum, anterior wall and lateral wall, respectively. They were close to the previously reported MBF values of 100 ml/min/100 ml. Therefore, we were able to obtain reasonably accurate MBF values non-invasively. (author)