A Spatial Scan Statistic for Stochastic Scan Partitions

Abstract

This article develops a spatial scan statistic for homogeneity analysis of point processes that utilizes stochastic scan partitions. The derivation of the sampling distribution for the statistic yields an exact test. This test has the potential for improved power over conventional alternatives when the point process is embedded in an underlying continuous random field and is recommended in situations for which the location of subregions of nonhomogeneity in the point process correspond to regions in the underlying field that can be segmented as distinct from their surroundings. The application to the detection of clustered microcalcifications in digital mammography is investigated as a motivating example.

Key Words:

• Cluster detection
• Digital mammography
• Homogeneity
• Image analysis
• Poisson dispersion
• Random field.