[en] Dynamic CT scans were conducted on 94 persons who had been randomly selected among the patients and the volunteers. The test results were used to obtain the time-density curve. A part of the subjects (20 cases) underwent the renogram examination for the comparative studies. The cortico-aortic (CA) ratio derived from the time-density curve demonstrated good correlation between the dynamic CT and the renal function (r=0.68). When the dynamic CT studies and the renogram were compared, the vascular phase of the renogram showed strong correlation with CA ratio. Consequently the dynamic CT study with CA ratio was believed to demonstrate the renal function. (author)