Vascular territories and watersheds: a zonal frequency analysis of the gyral and sulcal extent of cerebral infarcts. Part I: the anatomic template.

Our purpose was to establish a template of upper cerebral anatomy suitable for analysis of infarct distribution and for comparison among infarct types. We made a standard diagram of the key gyri and sulci of the supraventricular and occipital regions, partitioned the gray matter and white matter into specific zones useful for analyzing infarcts by CT and MRI, and numbered each zone uniquely in to establish a template suitable for tabulating the precise regions affected by each infarct and for analyzing differences among infarcts. The template provides a method for extracting a standardized set of data from CT or MRI performed at any angle, reconfiguring those data into a standard image, and characterizing the specific portions of infarcted brain in terms of unique numbers suitable for tabulation, collation and comparison. Standardization of the format provides for later computer analysis of increasing numbers of diverse infarcts. This method may be extended to any other type of pathology, although successful analysis of different lesions may require partitioning the gray and white matter zones in different ways.