A compact blood clot filter having an alignment section that overlaps with a filter section in an axial direction is provided. The filter section has filter struts that extend radially and longitudinally from a hub. The alignment section has alignment struts in which the downstream end of each alignment strut forms a downstream junction with the downstream end of an adjacent alignment strut while the upstream end of each alignment strut forms an upstream junction with the upstream end of an adjacent alignment strut.