This poster was presented as a technical demonstration as Poster #250 at the Fifth International Conference on Functional Mapping of the Human Mapping (HBM'99) held in Düsseldorf, Germany, June 22-26, 1999.

The abstract for this poster was published in NeuroImage, vol. 9, part 2, pg. S250, 1999.

CIRCLEPACK: SOFTWARE FOR CREATING QUASI- CONFORMAL FLAT MAPS OF THE BRAIN 1Monica K. Hurdal, 1De Witt L. Sumners, 2Ken Stephenson, 1Philip L. Bowers, 3,4David A. Rottenberg 1Department of Mathematics, Florida State University, Tallahassee, FL, U.S.A. 2Department of Mathematics, University of Tennessee, Knoxville, TN, U.S.A. 3PET Imaging Center, VA Medical Center, Minneapolis, MN, U.S.A. 4Department of Radiology, University of Minnesota, Minneapolis, MN, U.S.A. 1,2,3,4Members of the International Neuroimaging Consortium

Abstract cortical flat maps serve as a visualization tool that enhance informational content of functional and anatomical neuroimages by revealing spatial relationships not previously apparent flat maps may facilitate comparisons between individuals and groups of subjects We demonstrate software which can be used to create cortical flat maps that exhibit conformal behavior.

Advantages of Our Approach mapping is quasi-conformal (angular distortion is controlled) maps can be displayed in the Euclidean plane, hyperbolic plane, and on a sphere origin and distortion of flat maps in the hyperbolic plane can be interactively transformed in real time easy to impose a coordinate system and compare different maps conformal mappings are canonical and hence mathematically unique

For more information... on the applications of this software, see our poster "A Quasi-Conformal Flat Map of the Cerebellar Cortex" (poster #194) on the mathematics behind this approach, see our poster "Generating Conformal Flat Maps of the Cortical Surface Via Circle Packing" (poster #195) contact: Dr. Monica K. Hurdal, Department of Mathematics, Florida State University, Tallahassee, FL., U.S.A., 32306-4510. Phone: (+1-850) 644-7378; Email: mhurdal@math.fsu.edu; WWW: http://www.math.fsu.edu/~mhurdal or visit the International Neuroimaging Consortium page ( http://pet.med.va.gov:8080/incweb/). This work has been supported in part by NIH grants MH57180 and NS33718.