Under-reporting bicycle accidents to police in the COST TU1101 international survey: Cross-country comparisons and associated factors.

Police crash reports are often the main source for official data in many countries. However, with the exception of fatal crashes, crashes are often underreported in a biased manner. Consequently, the countermeasures adopted according to them may be inefficient. In the case of bicycle crashes, this bias is most acute and it probably varies across countries, with some of them being more prone to reporting accidents to police than others. Assessing if this bias occurs and the size of it can be of great importance for evaluating the risks associated with bicycling. This study utilized data collected in the COST TU1101 action "Towards safer bicycling through optimization of bicycle helmets and usage". The data came from an online survey that included questions related to bicyclists' attitudes, behaviour, cycling habits, accidents, and patterns of use of helmets. The survey was filled by 8655 bicyclists from 30 different countries. After applying various exclusion factors, 7015 questionnaires filled by adult cyclists from 17 countries, each with at least 100 valid responses, remained in our sample. The results showed that across all countries, an average of only 10% of all crashes were reported to the police, with a wide range among countries: from a minimum of 0.0% (Israel) and 2.6% (Croatia) to a maximum of a 35.0% (Germany). Some factors associated with the reporting levels were type of crash, type of vehicle involved, and injury severity. No relation was found between the likelihood of reporting and the cyclist's gender, age, educational level, marital status, being a parent, use of helmet, and type of bicycle. The significant under-reporting - including injury crashes that do not lead to hospitalization - justifies the use of self-report survey data for assessment of bicycling crash patterns as they relate to (1) crash risk issues such as location, infrastructure, cyclists' characteristics, and use of helmet and (2) strategic approaches to bicycle crash prevention and injury reduction.

[The radiologic report and its readability]. / Il referto radiologico e la sua leggibilità.

AIM: The aim of this study was to evaluate the readability of radiologic reports and to determine whether they can be improved by modifying then according to precisely defined rules. MATERIAL AND METHODS: Forty reports, 10 for each diagnostic procedure (conventional radiography, US, CT, MRI); were randomly selected from a corpus of 400. The reports were analysed quantitatively using a dedicated software and qualitatively taking into account the formal, syntactic and lexical aspects of linguistically correct language and specially defined rules. On the basis of the collected results the reports were modified and analysed. RESULTS: Once again the modifications resulted in increased legibility (as testified by readability indices) that was more evident in US and X-ray reports and less evident in CT and MR reports because of the quantity of technical terms. It hoped that a radiological lexicon and guidelines for report writing will be widely adapted, so that radiologic reports will be more readable and easy understand.

Distance perception of vehicle rear lights in fog.

Perceptual difficulty is one of the main explanations given for the behavioral modifications and high accident rate associated with driving in fog. The present study investigates how fog and the characteristics of vehicle rear lights affect distance perception. Two experiments in a fog chamber (meteorological visibility range of 5-15 m) were run under conditions simulating nighttime fog. The participants gave verbal estimates of the distance (8-28 m) of vehicles simulated by rear-light arrangements. The results revealed an average increase of 60% in the perceived distance of vehicles in fog as compared with normal visibility conditions. Distance overestimation was particularly pronounced when the vehicle had only 1 fog light instead of 2 and when the lights were close together. No effect of light height was observed. These results suggest that the perception of vehicle distance in nighttime fog could be significantly improved by the presence of 2 lights with maximal spacing. Actual or potential applications of this research include vehicle rear light design.

[Three-dimensional ultrasonography. Experience with a non-dedicated system]. / L'ecografia tridimensionale. Esperienza con un sistema non dedicato.

The application of three-dimensional (3D) reconstructions to US has been recently proposed, but remains strongly limited by the difficulty to produce parallel and equidistant slices and by the obvious lack of method standardization. This work describes our experience with a workstation on the market in producing 3D images from US exams. Reconstruction involved the following steps: acquisition (US examinations of different organs--i.e. carotid artery, parotid gland, kidney, gallbladder, urinary bladder--were recorded on VHS tape; a small, self-built, motor-driven mechanical arm was used to move the probe along the selected axis of the organ: a 486-class computer with a framegrabbing card was used during the digitizing process to produce a set of slices, white were saved in 320 x 256 x 8 bit format), pre-processing and segmentation (we used interactive contrast enhancement as a pre-processing technique, to emphasize contrast between echoic and anechoic structures or between solid structures with a small difference in echogenicity; as a segmentation technique, we used autotracing with a selected seed point; in a small number of images, where the software could not provide an adequate delimitation, we had to operate manually) and rendering. A commercially available software for radiological use (Analyze-Mayo Foundation, USA) was used for processing, segmentation and rendering. The rendered images can be visualized with multiple zoom factors, rotated and cut on any plane, reconstructed from every user-definable point of view. The good results indicate that 3D acquisition and reconstruction will probably change the way to obtain, display and study US findings.

HRCT evaluation of secondary lobules and acini of the lung.

We evaluated normal lung parenchyma with high-resolution computed tomography (HRCT) to assess the visibility of lobular and sublobular structures. Series of HRCT slices were obtained using the usual parameters for HRCT examinations. We used a limited reconstruction field (4-10 cm) with a narrow window to increase visibility of small structures. The boundaries of normal secondary lobules are difficult to identify because the septa are very thin; interstitial disease may increase septal thickness so that more lobules become visible. Position and approximate morphology of lobules can be identified, however, by observing the centrolobular bundles. Normally, many acini are usually visible; their mean diameter (6 mm) and thickness of periacinar capillary net (approximately 0.3 mm) make them identifiable with modern CT scanners. In conclusion, a good knowledge of HRCT lung anatomy is essential to correctly evaluate early interstitial disease.

HRCT studies of lung anatomy.

An accurate definition of lung anatomy is the first, necessary step to obtain an accurate and early diagnosis of diffuse and focal lung disease with HRCT. Secondary lobules are visible with conventional CT and HRCT as polygonal portions of lung parenchyma, surrounded by thin and incomplete septa and centred by a dense dot; acini are sometimes visible as rounded structures with a central dot. Morphological definition of these structures in normal subjects will greatly help in characterizing early signs of parenchymal disease.

[An expert system for the staging and therapy of carcinoma of the bladder]. / Sistema esperto per la stadiazione e la terapia del carcinoma della vescica.

Expert systems are application tools based on logic and containing a wide knowledge in a specific field; their aim is the simulation of an expert's behavior in reasoning and making decisions inherent a small cultural domain. Applications in medicine and radiology are numerous and constantly increasing. The possibility of their use in the application of diagnostic and staging protocols seems particularly interesting. The development and commercial availability of expert systems programming tools (called shells) make it certainly easier to develop consultations systems, even to non-experienced users. The purpose of this research is the definition and description of the stages encountered during the development of an expert system for diagnosis, staging and treatment of bladder cancer using self-developed shell, designed for radiological use, called Experto. The steps of knowledge collection, definition of diagnostic and therapeutic protocols and system development are described. The consultation system assessed the correct TNM stage of the 27 examined cases.

[Radiological reasoning and its computer-based simulation. Reasons to use computer-based diagnostic systems developed on shells]. / Il ragionamento radiologico e la sua simulazione informatica. Motivazioni per l'impiego di sistemi di aiuto alla diagnosi sviluppati su shell.

Research on the medical applications of artificial intelligence has increased the knowledge of logical and methodological principles of clinical reasoning. Thus, computer-based diagnostic systems are developed on the basis of progress in this field, because thorough knowledge is necessary to obtain efficient simulation. This work was aimed at analyzing the structure of medical and radiological reasoning and at discussing the modalities to simulate it with computer-based diagnostic systems. The diagnostic process includes two steps: data collection and data interpretation; radiological reasoning involves the following 5 steps: procedural, executive, observative, interpretative and communicative. Each of them needs a different approach to simulation, considering, in its development, the different characteristics of each kind of reasoning. The expert system shells on the market are necessary tools to develop expert systems, but they cannot cover the whole of processes taking place during radiological work. Therefore, a particular, radiology-aimed shell should be developed to help the radiologist.

[A proposal of an original system of "voice-mediated input" in radiological reporting]. / Proposta di un sistema originale di "input vocale mediato" nella refertazione radiologica.

The recent introduction of vocal input systems in diagnostic radiology will produce many changes in reporting. Statistical analyses of the texts put in (the so-called "mediated vocal input") are an interesting possibility which allows the radiologist to evaluate both readability and efficacy of his reports. The structure of a vocal input system is also suitable to define standardized vocabularies of commonly used radiological terms. This paper describes the structure of an original system, built by assembling low-cost components, with a self-made software. The aim is the reduction of noise in the communication between the radiologist and the physician, by means of new solutions which will make the radiological report one of the key points of the diagnostic procedure.

[Proposal of a conversion and processing system of digital images]. / Proposta di un sistema di conversione ed elaborazione di immagini digitali.

The digital format of diagnostic images is gradually replacing the analogic one, as expected, thanks to its diagnostic, gestional, and economic advantages. Digital radiology is expanding, crossing the borders of conventional radiology: the spread of photostimulable plates will cancel all differences, offering a "digital dimension" to conventional examinations, that will produce numeric images using the conventional method. Off-line systems are a most useful approach to numeric format, because they offer diagnostic and gestional advantages at a low price. Moreover, they allow analogic images to be put into the "digital flow" of radiological departments, thus making a format standardization possible between different types of images. The system proposed has advanced characteristics, such as acquisition, reconstruction and visualization of digital images with a 2560 x 2048 x 8 bit matrix. The use of two scanning systems (CCD and laser scanner) has proved to be the most effective way to acquire images with different resolution, while the use of a 2k x 2k monitor makes both observation and reporting at the workstation more reliable.

How is gait visually regulated when the head is travelling faster than the legs?

Gait regulation patterns were examined under various visual conditions in order to determine whether speed information provided by peripheral vision is taken into account in gait adjustments. Nine subjects walking toward a visual target on the ground were required to place one foot exactly on it. peripheral vision was either restricted to a 12 degrees angle or decorrelated, corresponding to a moving speed greater than the actual walking speed. Decorrelation was obtained by placing the subject on a treadmill moving in the walking direction. The results show, by comparison with the control condition, that the restriction of peripheral visual information did not affect the accuracy of the foot positioning, whereas decorrelated conditions affected it significantly: we noted that the gait regulation was triggered early on and showed a very stable pattern so that the distance to the target was consistently underestimated. This suggest that, although visual speed information is not indispensable in this kind of task, it is nevertheless taken into account in stride adjustments when the whole visual field is available. The results are discussed, in the context of a time-based approach to locomotor activity, in relation to the possible visual methods that might be used in obtaining information about time to contact the target.

Visual information and skill level in time-to-collision estimation.

Previous studies on the visual origin of time-to-collision (Tc) information have demonstrated that Tc estimates can be based solely on the processing of target expansion rate (optic variable tau). But in the simulated situations used (film clips), there was little reliable information on speed (owing to reduced peripheral vision) and distance (owing to the absence of binocular distance cues) available. In order to determine whether these kinds of information are also taken into account, it is necessary to take an approach where the subject receives a more complete visual input. Thus, an experiment conducted on a circuit under actual driving conditions is reported. Experienced drivers and beginners, who were passengers in a car, had to indicate the moment they expected a collision with a stationary obstacle to take place. Subjects were blindfolded after a viewing time of 3 s. The conditions for speed evaluation (normal versus restricted visual field) and distance evaluation (binocular versus monocular vision) by subjects were varied. The approach speed (30 and 90 km h-1) and actual Tc (3 and 6 s) were also varied. The results show that accuracy of Tc estimation increased with (i) normal visual field, (ii) binocular vision, (iii) higher speeds, and (iv) driving experience. These findings have been interpreted as indicating that both speed and distance information are taken into account in Tc estimation. They suggest furthermore that these two kinds of information may be used differently depending on the skill level of the subject. The results are discussed in terms of the complementarity of the various potentially usable visual means of obtaining Tc information.