Since the introduction of ultrasonography, liver steatosis has become an increasingly frequent diagnosis. Both ultrasonography (US) and computerized tomography (CT) provide qualitative rather than quantitative assessment of fatty infiltration. The objective of this study was to develop a noninvasive method for the quantification of the hepatic fat content in vivo. A test object containing solutions with CT scan density (CTD) similar to normal liver ("liver-equivalent") or "fat-equivalent material" in variable proportions was prepared to measure patients with variable degrees of steatosis in vivo.