Although organ weight gives pathologists information about the pathogenesis of diseases at autopsy, the knowledge is rarely helpful in postmortem virtual autopsy by computed tomography (CT). To investigate the feasibility of liver weight estimation based on liver volume estimated from three-dimensional CT images and the specific gravity of liver, thirty cadavers who died in the University of Fukui Hospital and whose family members agreed to postmortem CT and autopsy were prospectively enrolled. Mean specific gravity of liver was 1.054 ± 0.009 g/mL (95% confidence interval: 1.0507-1.0573 g/mL). The specific gravity was positively correlated to Hounsfield unit (HU) values of less than 40 (cases with moderate to severe fatty deposition) and remained stable between 1.05 to 1.065 g/mL for HU values greater than 40 (cases with mild or no fatty change). The liver weight estimated by our formula corresponded well to the actual liver weight, and the correlation coefficient was 0.96 (P < 1 × 10
−13). The estimated liver weight calculated from estimated liver volume and the specific gravity of 1.055 g/mL was highly accurate, whereas the specific gravity should be reduced by 2%-3% in patients with an HU value less than 40 due to fatty deposition.Key words: autopsy, liver weight estimation, postmortem CT, specific gravity of liver Autopsy is useful for quality control, education, and epidemiological data in clinical medicine.1,2 More than a powerful tool for quality improvement in patient care, the autopsy generates accurate vital statistics, provides a better understanding of diseases, and drives progress in medicine. 3 The procedure, which has changed little since the 19th century, consists of macroscopic observation, such as evisceration and measurement of the major organs, followed by histological analysis. [4][5][6] Many physicians worldwide are concerned about decreased autopsy rates, 1,7 which are assumed to be at least partially caused by clinical disinterest. Indeed, the determination of organ measurements (e.g., organ weights) is rarely helpful in routine medical practice, although the results give pathologists information about underlying diseases and/or conditions of deceased patients. In contrast to the decrease in autopsy rates, the frequency of postmortem imaging is increasing as a supplement to the traditional autopsy. Postmortem computed tomography (CT) and magnetic resonance imaging (MRI) are useful for determining the cause of death in Japan [8][9][10][11] and in Western countries. 2,4,5 Since 1994, the frequency of living-donor liver transplantation has been increasing due to the lack of cadaveric liver donors.12,13 Reliable liver weight estimation in transplantation is crucial for the safety of donors and recipients. Therefore, several physicians sought to estimate the liver weight for living-donor liver transplantation.14,15 However, the estimation formula is based on the height and weight of the donor, 16 and the reliability of the formula is unknown. This is partly due to the difficulty in validating ...