Arterialization of the portal vein is being propagated as a technical possibility in liver transplant recipients with pre‐existing portal vein thrombosis. In our own small sries, portal vein arterialization (PVA) was carried out in four patients undergoing orthotopic liver transplantation. In three of these cases, the portal vein was anastomosed to the aorta via an interposed iliac artery, and in one case, directly to the hepatic artery. After PVA, all transplants showed regular initial function. Two patients died postoperatively afer 19 and 50 days, of intra‐abdominal haemorrhage and liver necrosis with thrombosis of the portal vein, respectively. A further patient had previously developed fibrosis of the liver, which led to the death of the patient 11 months after PVA. In the remaining patient, chronic rejection requiring re‐transplantation developed 24 months after PVA had been performed. These unfavourable results prompt the conclusion that PVA cannot be recommended as a stndard clinical procedure.

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How is heading direction maintained in human gait? This question was investigated with respect to the role of optic flow and in the context of different movement strategies. While walking on a treadmill the deviation from the ideal straight path was measured in terms of lateral sway induced by a lateral gaze shift (by looking at a moving visual target). The role of the focus of expansion (FOE) within a radially expanding optic flow pattern was investigated by varying its relative velocity of expansion from 0- to 4-fold (the equivalent of walking speed), thus increasing the perceptibility of FOE. If FOE was a relevant cue for maintaining heading direction, a reduction of lateral sway amplitude was expected with increasing flow velocity. The presence of a radially expanding flow pattern did not reduce lateral sway. Lateral sway was least when the visual background remained stable without any flow pattern. Increasing the velocity of the flow pattern resulted in an increase in lateral sway. If the relative velocity of the flow pattern was raised beyond that corresponding to walking speed, lateral sway amplitude approached the maximal values observed in the dark. In all experiments, sway amplitude increased linearly with the increasing excursion of the visual target. Different strategies to perform the gaze shift (eye or head turns) only resulted in minor differences in lateral sway amplitude. The results show that gaze shifts during locomotion induce lateral sway, which depends upon the presence, and characteristics, of background optic flow. Under the present conditions, the FOE within the flow field seems not to be a dominant cue to control heading. However, the systematic increase in lateral sway induced by high flow velocities indicates that motion parallax has an effect on heading during locomotion.

Tomosynthesis has the potential to increase the sensitivity of digital mammography. Overlapping structures from out-of-plane tissue can be removed in the tomosynthesis reconstruction process, thereby enhancing the diagnostic accuracy.

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