Abstract 2940: Assessment of Left Ventricular Function and Mass in Computed Tomography Coronary Angiography Using Dual Source Computed Tomography: Comparison to Magnetic Resonance Imaging
Background: Left ventricular function and mass are predictive markers in a variety of cardiovascular diseases.
Purpose: The aim of the study was to quantify left ventricular function and mass derived from retrospectively ECG-gated dual source computed tomography (DSCT) coronary angiography data sets in comparison to cardiac magnetic resonance imaging (CMR) as the reference standard.
Methods: 26 consecutive patients (mean age 55 ± 8 years) with suspected coronary artery disease underwent DSCT coronary angiography (Siemens Definition). Patients (n=11) whose heart rates exceeded 70 bpm received up to four vials (20 mg) of metoprolol i.v. before DSCT examination. Multiplanar reformations in short-axis orientation in end-systole and end-diastole were calculated from retrospectively ECG-gated axial contrast-enhanced CT images. Left ventricular ejection fraction (EF), end-systolic volume (ESV), end-diastolic volume (EDV), stroke volume (SV), cardiac output (CO), and left ventricular myocardial mass (LVMM) were calculated and compared to volumetric measurements based on contiguous short-axis steady-state free precession cine MR sequences. Mean values were compared using a Wilcoxon sign rank test. P values <0.05 were considered statistically significant.
Results: Mean heart rate during DSCT examinations (60 ± 11 bpm) was significantly lower (p<0.05) compared to the CMR examination (66 ± 11 bpm). Mean EF (DSCT, 64 ± 9 %; CMR, 64 ± 8 %), mean ESV (DSCT, 49 ± 22ml; CMR, 53 ± 23 ml), mean EDV (DSCT, 134 ± 37 ml; CMR, 141 ± 37 ml), SV (DSCT, 85 ± 21 ml; CMR, 89 ± 19 ml), CO (DSCT, 5.2 ± 1.2 l/min; CMR, 5.8 ± 1.3 l/min) were not significantly different between both imaging modalities. LVMM calculated from DSCT data sets (178 ± 30 g) was significantly higher as compared to CMR(135 ± 36 g; p<0.05). DSCT data sets in patients with betablockers showed a trend towards a lower ejection fraction (DSCT, 62 ± 11%; CMR, 66 ± 8%; n.s.).
Conclusion: Left ventricular volumes can reliably be assessed by dual source computed tomography compared to CMR. However, left ventricular mass measured by DSCT is significantly overestimated compared to CMR. Further studies are required to evaluate the impact of betablocker premedication on left ventricular function in DSCT examinations.