Athena: A Macintosh-Based Interactive Karyotyping System

In this article we describe a system we have constructed that provides for automated karyotyping of metaphase spreads. The software system Athena – based upon the Macintosh II computer and a Data Translation's frame grabber – is written entirely in C and consists of approximately 200 Kbytes of executable code. While Athena does not provide (at this time) facilities for automated metaphase finding, it does provide facilities for automated image segmentation into individual chromosomes, automated measurements on each banded chromosome, and automated classification into the standard Paris-convention karyotype. Further, the system provides the ability to construct one or more chromosome data bases to represent the types of metaphase spreads and staining techniques that may be used in a given laboratory. Because we believe that it is impossible to construct a system that can achieve perfect segmentation, perfect separation of touching and overlapping chromosomes, perfect localization of the centromeres, and perfect classification, the system offers the possibility for interaction at each of the above stages using the well-accepted Macintosh user interface. The processing time for the complete analysis of a 5122 image that contains a metaphase spread, interphase nuclei, debris and so forth depends heavily on the 'quality' of the metaphase image. Depending upon the number of interactions required to complete the segmentation, the total processing time varies from less than 3 minutes for nice metaphase spreads to about 6 minutes when many chromosomes need to be separated manually using the mouse. Of that time 90 seconds represents the automated processing and the rest the time for human interaction. This is on a personal computer that uses a MC-68020 processor with a clock frequency of 16 MHz and a MC-68881 floating point co-processor. L.J. van Vliet, I.T. Young, T.K. ten Kate, B.H. Mayall, F.C.A. Groen, R. Roos in: Automation of Cytogenetics, C. Lundsteen & J. Piper (eds), Springer-Verlag, 1989, 47-66. 2