[The determination of left and right ventricular ejection and filling functions of the heart by fast cine MRT in the breath-hold technic in subjects]

Reliability and reproducibility of quantitative assessment of left ventricular function and volumes with 3-slice segmentation of cine steady-state free precession short axis images

OBJECTIVES

Quantitative assessment of left ventricular (LV) functional parameters in cardiac MR requires time-consuming contour tracing across multiple short axis images. This study assesses global LV functional parameters using 3-slice segmentation on steady state free precision (SSFP) cine short axis images and compares the results with conventional multi-slice segmentation of LV.

METHODS

Data were collected from 61 patients who underwent cardiac MRI for various clinical indications. Semi-automated cardiac MR software was used to trace LV contours both at multiple slices from base to apex as well as just 3 slices (base, mid, and apical) by two readers. Left ventricular ejection fraction (LVEF), LV volumes, and LV mass were calculated using both methods.

RESULTS

Bland-Altman plot revealed narrow limits of agreement (-4.4% to 5.1%) between LVEF obtained by the two methods. Bland-Altman analysis showed slightly wider limits of agreement between end-diastolic volumes (-5.0 to 12.0%; -3.9 to 8.5 ml/m(2)), end-systolic volumes (-10.9 to 14.7%; -4.1 to 6.5 ml/m(2)), and LV mass (-5.2 to 12.7%; -4.8 to 10.2g/m(2)) obtained by the two methods. There was a small mean difference between LV volumes and LV mass obtained using multi-slice and 3-slice segmentation. No statistically significant difference existed between the LV parameters obtained by the two readers using 3-slice segmentation (p>0.05). Multi-slice assessment required approximately 15 min per study while 3-slice assessment required less than 5 min.

CONCLUSIONS

3-slice segmentation of the left ventricle at basal, mid, and apical levels on cine SSFP short axis images can provide rapid and reliable assessment of LVEF with good reproducibility. The 3-slice method also provides a reasonable estimate of the LV volumes and LV mass.

Smoking and atherosclerotic cardiovascular disease: part III: functional biomarkers influenced by smoking

Smoking cigarettes induces rapidly occurring and reversible functional changes in the cardiovascular system, which precede morphologic changes. These functional changes are also related to atherosclerotic disease development and thus may qualify as prognostic parameters in chronic smokers. As opposed to smoking-induced morphologic changes functional alterations occur and revert within minutes, thus, allowing for the detection of smoking-induced effects on the cardiovascular system within minutes following exposure to mainstream smoke. Some alterations represent 'direct' changes (e.g., endothelial function), others reflect changes in a different organ system (e.g., the autonomous nervous system influencing heart rate variability), while some represent the sum of alterations in many organs and systems (e.g., exercise performance influenced by the autonomous nervous and by endothelial and cardiac function). Since a specific functional parameter usually changes with at least one or several others, caution should be exercised when trying to establish a direct cause relationship between the alteration of a single parameter and a clinical outcome.

Changes in left and right ventricular cardiac function after valve replacement for aortic stenosis determined by cine MR imaging

The purpose of this study was to determine the changes in function of both the left and the right ventricles (LV, RV) before and after aortic valve replacement (AVR), compared with age-matched healthy volunteers using magnetic resonance (MR) imaging. Fourteen patients with aortic stenosis underwent MR imaging (1.5 T) before and 3 (n = 14) and 12 (n = 9) months after surgical valve replacement. An electrocardiographically triggered two-dimensional cine fast low-angle shot sequence was used for the evaluation of absolute values and indices related to 1 m(2) body surface area for function, mass, and LV wall thickening. Fourteen age-matched healthy volunteers served as controls. Before surgery, all patients showed significant abnormalities of LV mass and function, whereas RV mass and function were not different from those of volunteers and remained mostly unchanged. After surgery, normalization of LV ejection fraction, absolute mass, and end-systolic wall thickness was observed, whereas the LV mass index failed to normalize, and LV volumes remained elevated. Aortic stenosis combined with a significant, but not severe reduction in LV function only affects the LV, whereas the RV remains unaffected at this stage of disease. AVR leads to improved LV function and reduced hypertrophy, but without normalization of LV volumes or the LV mass index within 1 year.