Development of modified method for quantification of regional myocardial blood flow using 15O-water with PET

We have designed a new practical algorithm, which allows stable, rapid and automated quantification of regional MBF using O-15-water with PET. Methods: Thirty-six volunteers were employed in the static O-15-CO and dynamic O-15-water PET studies. To evaluate the reproducibility of the estimates, a repeat O-15-water scan was carried out. This algorithm includes a procedure for positioning a three-dimensional region of interest (ROI) of the whole myocardium and dividing it into 16 segments. Subsequently, the uniform input function was calculated using time-activity curves in the whole myocardial ROI and in the left ventricular ROI. The uniform input function allowed a simple and robust algorithm to estimate regional MBF. Estimates were compared with those by an original method. A simulation study was carried out to compare the effects of errors in PTF or Va on the MBF using the two methods. Results: The average analyzing time to define whole and 16 regional myocardial ROIs was less than 5 min. The new method yielded less deviated regional MBF than those with the traditional method. This method yielded significantly higher reproducibility of regional MBF than the original method. Our new method yielded a better correlation in the repeated measurement values of regional MBF and less variability among the regions in the myocardium than with an original theory of O-15-water technique. The simulation study demonstrated less effects of error in PTF or Va on the MBF value with the new method. Conclusions: We have developed a technique for an automated, simplified and stable algorithm to quantify regional MBF. This software is considered to be practical for clinical use in a myocardial PET study using O-15-water with high reproducibility and short processing time. (C) 2004 Published by Elsevier B.V.