MEASUREMENT OF RIGHT-VENTRICULAR VOLUME IN HUMAN EXPLANTED HEARTS USING ULTRAFAST CINE COMPUTED-TOMOGRAPHY

The quantitative measurement of right ventricular (RV) volume has been attempted by a number of methods, including nuclear magnetic resonanc e imaging, contrast angiography, echocardiography, and radionuclide an giography. All of these methods have limitations. Ultrafast cine compu ted tomographic (CT) scan is a new technology that may have an importa nt role in on-line ventricular volume measurements. Twelve human expla nted hearts, fixed in formalin, were subjected to ultrafast cine CT sc ans to estimate RV volume. The volumes derived from the CT scans were compared with actual fluid volumes needed to fill the RV volume measur ements. All measurements were conducted independently by two observers . Actual RV volumes in the 12 hearts ranged from 29.8 ml to 174.6 ml. A strongly significant correlation between actual volume and CT volume was seen (r = 0.99). Agreement between observers was also seen to be highly significant (r = 0.992). Limitations to accurate in vivo assess ment due to bolus injection of contrast medium might include alteratio ns in ventricular pressure change. Similarly, differentiation of the e ndocardial border with contrast may not be as sharp as that with an ai r-tissue interface. This study demonstrates that RV volumes can be rel iably determined by ultrafast cine CT scans in explanted hearts. On-li ne systolic and diastolic volumes and thus stroke volume, ejection fra ction, etc, can be accurately defined independent of cardiac orientati on. This technique offers opportunities to study ventricular function under various conditions.