The galactose elimination capacity, a measure of the functional liver cell mass, and liver volume were measured in 50 normal subjects of five different age groups (less than 50, 51 to 60, 61 to 70, 71 to 80 and greater than 81 years). The volume of the liver was evaluated by ultrasonography. All subjects had normal routine liver function tests and no history of liver disease. Galactose elimination progressively decreased from 3.05 +/- 0.58 (S.D.) mmoles per min in younger subjects to 1.83 +/- 0.24 mmoles per min in subjects over 81 (p less than 0.00003), without any change in the apparent volume of distribution of the sugar. Similarly, the estimated volume of the liver decreased from 110 +/- 14 units to 75 +/- 13 units with increasing age (p less than 0.0002). Both galactose elimination capacity and the estimated liver volume inversely correlated with age (r = -0.728 and r = -0.579, respectively) whereas a positive correlation was observed between galactose elimination and the estimated liver volume (r = 0.520). Part correlation analysis confirmed that age, when entered in a multiple regression already containing body weight and estimated liver volume as independent variables, had a significant effect on liver function, whereas no significant independent effect of liver volume was present. Both age and body weight had a significant independent effect on the estimated liver volume. The maximum functional capacity of the liver, measured by galactose elimination, is reduced in the elderly. Although several factors may play a role, our data suggest that aging is associated with a slight decline in the intrinsic metabolic activity of the hepatic parenchyma.

Blood flow in the splanchnic veins was studied in cirrhotics and matched controls by means of a system that combines a mechanical sector scanner with a pulsed Doppler. The measurements were validated in an in vitro model. Echo-doppler studies could be carried out reproducibly in only approximately two-thirds of cases because of poor echo transmission or incomplete cooperation. Portal blood velocity was significantly reduced in cirrhotics (10.5 +/- 0.6 cm/s versus 16.0 +/- 0.5 in controls; p less than 0.001), but portal blood flow was normal because of enlarged portal caliber. A complete hemodynamic evaluation of the splenic and superior mesenteric veins was possible in only a few subjects. In selected patients the technique may prove relevant in the study of hemodynamic effects of drugs and surgery on portal blood flow.

A method is described to calculate liver volume at US using real‐time equipment. The method is based on the measurement of the 3 maximum diameters of the liver. Equations were derived by correlation vs CT volume measurement using the 3 diameters (multiple regression) or their product (simple regression) as independent variables in 20 subjects with and without liver disease. It is suggested that liver volume may be estimated as: where y is the volume (in ml), and C – C, A – P, and L – L are the 3 diameters (in cm). The two equations were validated in a second set of 22 subjects. US volume estimated according to Eq. 2 explained approximately 82% of the variance of the actual liver volume. The method is reproducible (interobserver variations <8%), rapid and easy‐to‐repeat. These features make it potentially useful in prospective longitudinal studies.

Zygomatic implant rehabilitation is a challenging procedure that requires an accurate prosthetic and implant plan. The aim of this study was to evaluate the malar bone available for three-dimensional zygomatic implant placement on the possible trajectories exhibiting optimal occlusal emergence. After a preliminary analysis on 30 computed tomography (CT) scans of dentate patients to identify the ideal implant emergencies, we used 80 CT scans of edentulous patients to create two sagittal planes representing the possible trajectories of the anterior and posterior zygomatic implants. These planes were rotated clockwise on the ideal emergence points and three different hypothetical implant trajectories per zygoma were drawn for each slice. Then, the engageable malar bone and intra- and extra-sinus paths were measured. It was possible to identify the ideal implant emergences via anatomical landmarks with a high predictability. Significant differences were evident between males and females, between implants featuring anterior and those featuring posterior emergences, and between the different trajectories. The use of internal trajectories provided better bone engagement but required a higher intra-sinus path. A significant association was found between higher intra-sinus paths and lower crestal bone heights.