A method to create reference maps for evaluation of ultrasound images of carotid atherosclerotic plaque.

Ten formalin-fixed atherosclerotic carotid plaques removed by endarterectomy were molded into rectangular agar blocks containing fiducial markers on the top surface. Plaque and fiducial markers were imaged with 3-D multiangle ultrasound (US) spatial compounding as well as planar X ray. Subsequently, the blocks were decalcified, sliced, photographed and analyzed histologically. This gave a total of 123 slices. The plaque regions of the photographs were outlined and the outline adjusted to partly compensate for occasional displacement during slicing. Inside this outline, the material constitutions were found by incorporating the histologic information. From this set, slices with 1. too much tissue displacement due to cutting or 2. lack of identification of calcification as found by x ray, were removed. This resulted in 53 reference maps. The material types identified covered soft tissues, fibrous tissue, calcified tissue and unidentified tissues. The 53 reference maps can be used for direct automated quantitative comparison with US images.

[Accidents affecting potato harvesters]. / Ulykker med kartoffeloptagemaskiner.

During industrialization in agriculture, many farming machines have been introduced. It is well-known that farming is a dangerous workplace and that farm machinery cause many serious accidents every year. Four cases of accidents with potato harvesters are discussed. In three of four cases the farmers were injured while cleaning the machine without stopping it, which probably was the main cause of the accidents. Farmers are in general not careful enough when using farm machinery. Every year, farmers in Denmark are severely invalided in accidents with potato harvesters. A strategy to lower the accidents is proposed: 1. Information of farmers, farmer schools, machine constructors and importers about mechanisms of injury. 2. A better education of farmers in using potato harvesters (and other farming machines). 3. Better fencing of the potato harvesters. 4. If possibly constructional changes in the potato harvesters so things will not get stuck, or so that the machine will stop if things stuck. 5. Installation of switches on potato harvesters, which can be reached from all positions, stopping the machines immediately, or a remote switch control carried by the farmer.

[Violent and aggressive behavior among patients in emergency wards]. / Voldelig og aggressiv adfaerd blandt patienter i skadestuen.

The purpose of this investigation was to identify risk factors for violent and aggressive behaviour in patients in the Emergency Room (ER) with a view to suggesting prophylactic measures. From 1st December 1991 to 30th November 1992 all staff at the biggest ER in Denmark (Odense University Hospital) who had felt themselves exposed to aggressive or violent behaviour from patients answered a questionnaire about the incident. There were 47,013 contacts to the ER and 36 incidents involving violence or aggression towards hospital staff during the study period, corresponding to an incidence of 1/1306 patient contacts (0.08%), or one episode every ten days. In no cases did the violence result in staff injury requiring medical treatment, and there was only one case of dangerous violence (an aggressive patient threatened staff with a knife). The police were called in to assist in 50% of cases. Most (83%) of the incidents were caused by men. Seventy-five percent of the aggressive patients (including all six aggressive women) were easy to identify because they were visibly under the influence of either alcohol, narcotics of medications. Incidents occurred most commonly in the evenings, particularly weekends and holidays, which could possibly be associated with the general increase in alcohol consumption at these times. Long waiting-times were involved in 22% of the cases, and it is therefore proposed that waiting-times should be shortened by organizational changes. Review of the literature reveals that aggressive and assaultive behaviour is multifactorial, caused by a combination of personal and situational factors. Provoking factors in the ER environment are rarely recognized.(ABSTRACT TRUNCATED AT 250 WORDS)

Spiral computed tomographic imaging related to computerized ultrasonographic images of carotid plaque morphology and histology.

OBJECTIVE: Echolucency of carotid atherosclerotic plaques, as evaluated by computerized B-mode ultrasonographic images, has been associated with an increased incidence of brain infarcts on cerebral computed tomographic scans. We tested the hypotheses that characterization of carotid plaques on spiral computed tomographic images correlates with that on computerized B-mode ultrasonographic images and that spiral computed tomographic imaging predicts the histomorphometric plaque content. METHODS: The study included 38 patients with neurologic symptoms and at least 50% stenosis of the ipsilateral carotid artery. High-resolution B-mode ultrasonographic images and spiral computed tomographic images of carotid plaques were computer processed to yield a quantitative measure, the gray scale level of the plaque. RESULTS: The mean Hounsfield value for spiral computed tomographic images correlated with the gray scale median for B-mode ultrasonographic images (univariate linear regression analysis: r = 0.45; P = .01) and the histologic content of calcification in the plaque (r = 0.34; P = .04) but not with lipid, hemorrhage, or fibrous tissue in the plaque. CONCLUSIONS: Spiral computed tomographic imaging seems to correlate with B-mode ultrasonographic imaging for showing plaque characteristics. Spiral computed tomographic attenuation was also correlated with the amount of calcification noted on histologic examination but not with lipid and hemorrhage, the components thought to characterize vulnerable, rupture-prone plaques.