Hough transform for arcs/parabolas

Hi,

I have used the hough transform for line detection.  I understand that it can also be used for other geometries that are specified such as circles and arcs (parabolas).  I am working on an image analysis where this would be very useful (micrographs of additive manufacturing processes).  The transform included is for lines.  Has anyone done work on parabolas that could share so starting points?

Andy