ABSTRACT
This study has tested solutions to optimize the ability of factor analysis of the left ventricle in echocardiography (FALVE) to detect segmental wall motion abnormalities automatically. On four- and two-chamber views of 38 patients, two factors (one flat curve and one curve describing the contraction-relaxation sequence) were extracted and associated factor images were combined to synthesize a parametric image (constant image in green, positive/negative values of the contraction-relaxation image in red/blue). The segments were graded on the visual and the parametric views. The impact of selecting a whole cardiac cycle, masking the left ventricle and realigning the image sequence on the results, was demonstrated. Systematic realignment had a positive impact, especially for patients with left bundle branch block or pacemaker. After alignment, for the entire population, the absolute concordance was 68.6% and the relative concordance (within one grade) was 99%. Thus, FALVE is promising for detecting segmental wall motion abnormalities.
Subject(s)
Echocardiography/methods , Image Interpretation, Computer-Assisted , Image Processing, Computer-Assisted , Ventricular Dysfunction, Left/diagnostic imaging , Adult , Factor Analysis, Statistical , Female , Heart Ventricles , Humans , Male , Middle Aged , Myocardial ContractionABSTRACT
BACKGROUND: Factor analysis of the left ventricle in echography was developed to study the regional wall motion. Two factors and associated factor images were estimated using specific constraints: one "constant" factor and another "contraction-relaxation" factor. The constant factor was encoded in green, the positive component of the contraction in red and the negative in blue. METHODS: The evaluation was carried out on 12 patients with LBBB or pacemaker (group A), and on 26 others (group B). The segments were graded separately on the cine-loops by three experienced echocardiographers. Similarly, the three-color combination of the factor images was read at the endocardial border and each segment was scored. RESULTS: An absolute concordance was obtained for 64.8% of the segments and a relative concordance (within one grade) for 97.2%. They were 71% and 99.6% in group B. Most of the discordant cases were explained by the global motion during the cardiac cycle. The standard deviation of the difference between the mean wall motion scores was 0.38 for all the patients; it was reduced to 0.30 in group B. CONCLUSION: Factor analysis is a promising tool to study the regional wall motion. It might become useful for assessing segmental wall motion in 2D and 3D echo.
