Toward an automated system for the analysis of cytogenetic abnormalities using fluorescence in situ hybridization technique

In order to build an automatic system that searches, acquires and analyses chromosomal aberrations, we have coupled a commercial system, Metafer4 (MetaSystems, Germany), with an original software (VRAIC) that is able to separate normal from aberrant metaphase images. Images of metaphases are first stained with a FISH technique and then acquired in three different channels: a BLUE channel, where all chromosomes are stained, a RED channel and a GREEN channel, where only specific pairs of chromosomes are stained. The analysis takes place in three stages. Images are first segmented in the BLUE channel by an edge detection technique. Edge sets not belonging to chromosomal contours are then eliminated by thresholding techniques. Finally, segmentation obtained in the first stage is used to facilitate detection of chromosomal aberrations in the the RED and GREEN channels.