title: A simplified method for computerized densitometry of complex shapes in 2-deoxyglucose autoradiographs.
abstract: A simple, computerized densitometer is described which can be used to measure densities of photographic prints by means of a fiber-optic reflectance densitometric probe coupled to the movable cursor of a digitizing tablet. The cursor, with its attached probe, is moved by hand along a scan trajectory determined by the operator. In its configuration for use with 2-deoxyglucose autoradiographs, the histological section from which the autoradiograph was derived provides architectonic landmarks for guiding the path of the scan. The X, Y and density values taken along a scan line are sequentially stored in the computer memory. Algorithms are presented for plotting densities along unfolded scan lines within layers of structures with complicated shapes, for normalizing non-linearities introduced during photographic processing, for standardizing the data sets with reference to the density of average gray matter in different animals, for calculating total integrated density within defined boundaries along the scan line, for generating averages of multiple scans, and for stacking sequential scans to form pseudo-3-dimensional plots. This system allows densitometric measures to be made from autoradiographs in anatomically defined regions, thereby permitting precise correlation between isotope concentration and histological structure.
mesh_terms: D000818:Animals; D001345:Autoradiography / Q000295:instrumentation / Q000379:methods*; D001921:Brain / Q000378:metabolism*; D003201:Computers; D006224:Cricetinae; D003720:Densitometry / Q000295:instrumentation / Q000379:methods*; D003837:Deoxy Sugars / Q000378:metabolism*; D003847:Deoxyglucose / Q000378:metabolism*; D006168:Guinea Pigs; D051379:Mice; D009482:Neurophysiology / Q000295:instrumentation / Q000379:methods*
chemical_list: D003837:Deoxy Sugars; D003847:Deoxyglucose