Figure 1.

The schematic principle of MACI. The principle of transforming an ultrasound image sequence (a) to PCA (c) by means of the wavelet transform (b). A multivariate image space, an ultrasound loop—a series of images. (b) The congruent images are put as the rows of an ordinary two-way data table. This means that each row corresponds to a point, or frame, in time. The columns contain wavelet coefficients. (c) A two-component PCA score plot of the table of wavelet coefficients, i.e. the second score vector, t2, plotted against the first score vector, t1.