The function call graph relationships can be filtered to show only what you consider the most interesting paths. The “Call Graph Filtering” button in the Relation Window Properties dialog box takes you to a dialog box that lets you control the filtering by specifying particular functions you want to exclude. You can also filter functions out by code metrics constraints.
Note that Source Insight considers C macros legitimate function-like symbols, and so C macros may show up in a call graph. You can filter them out in the Call Graph Filtering dialog box if you want.