Estimation of the volume of the ventricles by radionuclide ventriculography

Since many years radionuclide ventriculography (RNV) is used in determining EF, rates of volume change and regional wall motion for diagnosing various heart diseases.EF as computed by means of RNV and contrast angiography correlates with r = 0.85 to r = 0.95. Other important parameters are the ventricular volumes which have to be determined when more precisely analysing the heart function. Using a model of a periodically beating ventricle with surrounding myocardium and background, EF and volumes were determined by means of RNV. The volumes were evaluated twice from the projected area F of the ventricle according to V = 4/3 √ F3/π, and by comparing the counts in the ventricular ROI with counts of a syringe of a certain volume. The correlation of true and measured EF and volumes was 0.98 and 0.96, respectively. In 75 patients, the correlation of the volumes as derived by the area method to the data of contrast angiography was rsub(EDV) = 0.72 and rsub(ESV) = 0.65. From our experience with the heart model we expect that also in patients the volumes can be determined more precisely when using the count method and that especially intraindividual changes of volumes can be detected with an error of only a few percent. (Author)