Abstract and Introduction
Abstract
Objective: The purpose of our study was to quantify left ventricular function and mass derived from retrospectively ECG-gated 16-MDCT coronary angiography data sets using a new analysis software based on automatic contour detection in comparison to corresponding standard of reference measurements acquired with MRI.
Subjects and Methods: Multiplanar reformations in the short-axis orientation were calculated from axial contrast-enhanced CT images in 18 patients (men, 15; women, three; age range, 38–70 years; mean, 57.4 ± 10.2 [SD] years) who were referred for CT coronary angiography. End-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF), and left ventricular mass (LVM) were analyzed with a recently developed imaging software using an automated contour detection algorithm of left ventricular endo- and epicardial contours and by manual tracing. The data were compared with similar measurements on MRI as the standard of reference.
Results: EDV, ESV, EF, and LVM derived from an automated contour detection algorithm were not statistically significantly different from manual tracing (CTauto vs CTmanual: EDV = 137.1 ± 45.7 mL vs 134.2 ± 39.9 mL, ESV = 58.8 ± 34.2 mL vs 58.1 ± 30.1 mL, EF = 59.2% ± 13.7% vs 58.1% ± 12.0%, LVM = 130.9 ± 29.1 g vs 133.7 ± 33.2 g; p > 0.05). However, EDV (118.7 ± 43.6 mL), ESV (50.1 ± 33.5 mL), and LVM (142.8 ± 38.4 g) as calculated on MR data sets were statistically significantly different from those calculated on CT ( p < 0.05), whereas MRI-based EF (59.9% ± 14.4%) did not differ statistically significantly from those based on both CT algorithms ( p > 0.05).
Conclusion: Automatic and manual analysis of data acquired during CT coronary angiography using a 16-MDCT scanner allows a reliable assessment of left ventricular ejection fraction and a rough estimation of left ventricular volumes and mass.
Introduction
Left ventricular volumes and function are predictive markers of a variety of cardiovascular diseases. Patients with both coronary artery disease and depressed left ventricular function are at high risk for sudden death, and left ventricular hypertrophy is associated with a significant excess of cardiovascular mortality and morbidity independent of the presence of coronary artery disease or arterial hypertension.[1,2] Therefore, a precise quantitative and qualitative assessment of left ventricular function and mass is indispensable.
In clinical practice, echocardiography has been established as the method of choice for determination of ventricular volumes and mass because of its wide availability and relatively short examination times. Considerable drawbacks inherent to echocardiography are operator dependence and rather poor contrast between blood and myocardium. Because of its multiplanar cross-sectional nature coupled with high spatial and temporal resolution and the different signal intensities between blood and myocardium, MRI has evolved as the standard of reference for quantification of left ventricular function and mass.[3,9]
During the past decade, CT scanners with four parallel slices and a gantry rotation time of 500 msec have been introduced clinically. This technique allows for the first time a reliable noninvasive visualization of the coronary artery lumen.[10,11] Recently published studies have shown that a new generation of MDCT scanners, equipped with more and thinner detector rows, allows reliable noninvasive detection of obstructive coronary artery disease[12] and dysfunctional bypass grafts.[13] Analysis of multiplanar reformations of such retrospectively ECG-gated CT coronary angiography data sets also permits the assessment of left ventricular parameters.[14,15]
In this study, using new CT analysis software, we intraindividually compared fully automatically and manually determined left ventricular function and mass measurements derived from retrospectively ECG-gated 16-MDCT coronary angiography examinations with those obtained by MRI.
