Cardiac volumetry in patients with heart failure and reduced ejection fraction: a comparative study correlating multi-slice computed tomography and magnetic resonance tomography. Reasons for intermodal disagreement

Background In humans with normal hearts multi-slice computed tomography (MSCT) based volumetry was shown to correlate well with the gold standard, cardiac magnetic resonance imaging (CMR). We correlated both techniques in patients with various degrees of heart failure and reduced ejection fraction (HFREF) resulting from cardiac dilatation. Methods Twenty-four patients with a left ventricular end-diastolic volume (LV-EDV) of >= 150 ml measured by angiography underwent MSCT and CMR scanning for left and right ventricular (LV, RV) volumetry. MSCT based short cardiac axis views were obtained beginning at the cardiac base advancing to the apex. These were reconstructed in 20 different time windows of the RR-interval (0-95%) serving for identification of enddiastole (ED) and end-systole (ES) and for planimetry. ED and ES volumes and the ejection fraction (EF) were calculated for LV and RV. MSCT based volumetry was compared with CMR. Results MSCT based LV volumetry significantly correlates with CMR as follows: LV-EDV r = 0.94, LV-ESV r = 0.98 and LV-EF r = 0.93, but significantly overestimates LV-EDV and LV-ESV and underestimates EF (P < 0.0001). MSCT based RV volumetry significantly correlates with CMR as follows: RV-EDV r = 0.79, RV-ESV r = 0.78 and RV-EF r = 0.73, but again significantly overestimates RV-EDV and RV-ESV and underestimates RV-EF (P < 0.0001). Conclusion When compared with CMR a continuous overestimation of volumes and underestimation of EF needs to be considered when applying MSCT in HFREF patients.