1. A system for determining background pixel representative image data of medical images of patient anatomy, comprising: an acquisition processor for receiving pixel luminance data comprising a plurality of sequential medical images of a patient anatomical portion and luminance data of an individual image comprises a plurality of pixel luminance representative values of a plurality of individual pixels of said individual image; a filter including a first filter function having a first response time for filtering received luminance representative values of a particular individual pixel varying in response to a first motion disturbance in said plurality of sequential medical images for use in identifying a substantially minimum luminance value of said particular individual pixel in said plurality of sequential medical images; wherein said filter includes a second filter function having a second response time for filtering received luminance representative values of said particular individual pixel varying in response to a second motion disturbance and an image data processor for applying said first and second filter in filtering luminance representative values of individual pixels of said plurality of sequential medical images to identify substantially minimum luminance values of individual pixels in said plurality of sequential medical images as background image data of said plurality of sequential medical images.