Assessment of abdominal organ motion using cine magnetic resonance imaging in different gastric motilities: a comparison between fasting and postprandial states

This study assessed abdominal organ motion induced by gastroduodenal motilities in volunteers during fasting and postprandial states, using cine magnetic resonance imaging (cine-MRI). Thirty-five volunteers underwent cine-MRI while holding their breath in the fasting and postprandial states. Gastric motility was quantified by the amplitude and velocity of antral peristaltic waves. Duodenal motility was evaluated as the change of duodenal diameter. Abdominal organ motion was measured in the liver, pancreas and kidneys. Motion was quantified by calculating maximal organ displacement in the left-right, antero-posterior and caudal-cranial directions. Median antral amplitude and velocity in the fasting and postprandial states were 7.7 and 15.1 mm (P < 0.01), and 1.3 and 2.5 mm/s (P < 0.01), respectively. Duodenal motility did not change. Median displacement for all organs ranged from 0.9 to 2.9 mm in the fasting state and from 1.0 to 2.9 mm in the postprandial state. Significant increases in abdominal organ displacement in the postprandial state were observed in the right lobe of the liver, pancreatic head and both kidneys. Differences in the median displacement of these organs between the two states were all <1 mm. Although the motion of several abdominal organs increased in the postprandial state, the difference between the two states was quite small. Thus, our study suggests that treatment planning and irradiation need not include strict management of gastric conditions, nor the addition of excess margins to compensate for differences in the intra-fractional abdominal organ motion under different gastric motilities in the fasting and postprandial states.

Who is responsible for global road safety? A cross-cultural comparison of Actor Maps

The traditional three 'E's approach to road safety (engineering, education, enforcement) has had, and will continue to have, a significant impact on road traffic casualty rates worldwide. Nevertheless, with rising motorisation in many countries, global fatality numbers have changed little over the past decade. Following calls for the application of sociotechnical systems thinking to the problem, we widen the road safety discussion with an additional four 'E's; economics, emergency response, enablement, and, the umbrella term for the approach taken, ergonomics. The research presents an application of Rasmussen's Risk Management Framework to the road safety systems of five distinct nations; Bangladesh, China, Kenya, the UK, and Vietnam. Following site visits, reviews of literature, and interviews with subject matter experts in each of the countries, a series of Actor Map models of the countries' road safety systems were developed. These are compared and discussed in terms of the wide variety of interconnecting organisations involved, their influences on road safety outcomes, the differences between nations, and the need to look beyond road users when designing road safety interventions.