[Ultrasonic myocardial characterization. Application of an original method of acoustic quantification to analysis of healthy and hypertrophic interventricular septal myocardium].
Echocardiography does not provide objective tissue characterisation of sonified tissues. A recent advance has been the introduction of the radiofrequency signal. At present, its exploitation remains a research tool. The required material for quantification is still insufficiently robust and discriminative. The indices derived from histograms of grey scales are calculated by the majority of workers for regions of interest manually positioned in the image. This statistical method allows analysis of the average grey level but not of the architecture of the tissue examined. Tissue characterisation is, therefore, only a potential feature of echocardiography. The authors' approach consists in developing software applied to digital signal provided by the echograph and not directly by the transducer, as in the research based on the use of radiofrequency signals. This software allows characterisation of the texture by two statistical methods applied to signal processing: the histograms of the grey scales, the matrix of co-occurrence (assessing the make-up of the different grey scales in the region of interest). This tool of tissue characterisation is presented here in the studies of the interventricular septum in the parasternal long axis view. Two populations, one with healthy myocardium and the other with myocardial hypertrophy, have been studied. These two populations are differentiated in a significant manner by their respective values of parameters of myocardial texture characterisation in early diastole. Despite a number of methodological problems, this study confirms the hopes that it will be possible in the near future to obtain a quantitative "histological" definition of tissues by echocardiography.
Donal
E
E
Département de cardiologie, CHU La Milétrie, Poitiers.
Coisne
D
D
Christiaens
L
L
Ragot
S
S
Herpin
D
D
Allal
J
J
D004452:Echocardiography / Q000379:methods*; D006346:Heart Septum / Q000000981:diagnostic imaging*; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging*; D017380:Hypertrophy, Right Ventricular / Q000000981:diagnostic imaging*; D008432:Mathematical Computing; D012984:Software