To gain insight into brain tumor invasion, experiments are conducted on multicellular tumor spheroids grown in collagen gel. Typically, a radius of invasion is reported, which is obtained by human measurement. We present a simple, heuristic algorithm for automated invasive radii estimation (AIRE) that uses local fluctuations of the image intensity. We then derive an analytical expression relating the image graininess to the cell density for a model imaging system. The result agrees with the experiment up to a multiplicative constant and thus describes a novel method for estimating the cell density from bright-field images.
© 2007 Optical Society of America
Original Manuscript: February 15, 2007
Revised Manuscript: May 7, 2007
Manuscript Accepted: May 19, 2007
Published: July 9, 2007
Vol. 2, Iss. 9 Virtual Journal for Biomedical Optics
Andrew M. Stein, Michal O. Nowicki, Tim Demuth, Michael E. Berens, Sean E. Lawler, E. Antonio Chiocca, and Leonard M. Sander, "Estimating the cell density and invasive radius of three-dimensional glioblastoma tumor spheroids grown in vitro," Appl. Opt. 46, 5110-5118 (2007)