Taking advantage of two scan modes of an electron beam CT scanner (Imatron), we have developed a method utilizing x-ray CT for relating pulmonary perfusion to global and regional anatomy. A high temporal resolution mode, used to follow bolus contrast agent, is combined with a high spatial resolution mode to obtain the structure-function fusion. A software module has been developed for our image analysis package (VIDA) to automatically calculate physiologic parameters of flow and integrate these color coded functional measurements into a corresponding high spatial resolution data set. We present the scanning methodology details and give examples from our physiologic based research to demonstrate strengths of combining dynamic and high resolution CT to uniquely characterize pulmonary normal and pathophysiology.