Effect of papillary muscle and trabeculae on left ventricular function analysis via computed tomography: A cross-sectional study

Figure 1.. Flow diagram for selection of normal control group (A) and patent group (B). In our health promotion center, 7431 people underwent cardiac CT, of which 3612 cases were normal cardiac CT, except for cases with any cardiac diseases. Finally, 288 normal controls were selected by balancing age and sex. Medical records of 6506 patients who were referred from our cardiovascular center and underwent cardiac CT were evaluated to extract patients diagnosed with HCMP, DCMP, and old MI. Among them, the rest of the patients were included in the study, except for patients whose cardiac function test using CT was omitted. BV = blood volume, CABG = coronary artery bypass grafting, CT = computed tomography, DCMP = dilated cardiomyopathy, F = female, HCMP = hypertrophic cardiomyopathy, M = male, MI = myocardial infarction, ST = standard.

Figure 2.. Representative example of 2 methods to measure LV function: (A and B) The standard (ST) Simpson method is based on automatic tracing of the endocardial (red line) and epicardial (green line) contours. The papillary muscle and trabeculae are not included in the left ventricular mass (LVM) but are included in the left ventricular volume. (C and D) The threshold-based blood volume (BV) method is based on attenuation differences between the LV blood pool and the myocardium. Because the attenuation values of the papillary muscle and trabeculae are below the threshold, they are not included in the left ventricular volume.

Figure 3.. In case with hypertrophic cardiomyopathy (HCMP), LV function were measured by standard (ST) Simpson method (A, B and E) and threshold-based blood volume (BV) method (C, D and F). LV ejection fractions (LVEF) measured by both methods are within normal range (E and F). The LV myocardial mass (LVM) measured by BV method is higher (249 g vs 194 g) compared with LVM measured by ST method. The proportions of papillary muscle and trabeculae to LV end-diastolic volume (LVEDV) and LVM are 42.1% and 22.3%, respectively.

Figure 4.. In case with dilated cardiomyopathy (DCMP), LV function were measured by standard (ST) Simpson method (A, B and E) and BV method (C, D and F). The LVEF decreased severely, and LVEDV increased markedly (E and F). The proportions of papillary muscle and trabeculae to LVEDV and LVM are 19.6% and 22.5%, respectively. BV = Threshold-based blood volume method.

Figure 5.. In case with old myocardial infarction (MI), LV function were measured by ST method (A, B and E) and BV method (C, D and F). Short axis view of LV myocardium (A and C) shows a decrease in wall thickness and fat deposition at left circumflex coronary artery territory. However, the LVLF was preserved within normal range (E and F). The proportions of papillary muscle and trabeculae to LVEDV and LVM are 22.5% and 24.0%, respectively. BV = Threshold-based blood volume method.