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PubMed2003

Teaching students how to read and write science: a mandatory course on scientific research and communication in medicine.

The authors describe the development and introduction of a course on scientific methodology and communication into the medical curriculum in a country outside of the mainstream scientific world. As editors of a general medical journal in Croatia, they learned that their colleagues had important and interesting data but no skills for presenting them in a scientific article. To alleviate the lack of education in research methodology and writing, the authors developed and introduced a mandatory course in scientific methodology and communication into the medical curriculum of the largest Croatian medical school. The course is structured into lectures, medium-sized-group discussions, and problem-solving small-group work, and is focused on (1) principles of scientific research; (2) access to medical literature and bibliographic databases; (3) study design and analysis and presentation of data; (4) assessing and writing a scientific article; and (5) responsible conduct of research. The course has been running since 1995-96 and is already showing results, visible in the more positive attitude of students toward scientific research and evidence-based medicine, and a significant number of students working on research projects and publishing scientific papers. The authors and colleagues also run continuing education courses for young academic physicians and an annual advanced workshop on scientific writing, involving academic physicians from all of southeastern Europe. The long-term goal is to create a critical mass of academic physicians with critical appraisal skills needed for evidence-based medicine and with skills for effectively communicating their research to the international scientific community.

Biomedical Research↗

PubMed1997

Evaluation of technical quality of endodontic treatment--reliability of intraoral radiographs.

The purpose of this study was to evaluate: 1) the use of the conventional buccolingual radiographic projection for estimating the technical quality of endodontic treatment and 2) the effect of the surrounding tissues on these evaluations. The material consisted of three radiographs of each of 108 extracted roots: a clinical radiograph, an in vitro radiograph taken in the buccolingual projection, and an in vitro radiograph taken in the mesiodistal projection. The radiographs were analysed by two observers and consensus was reached and used in the analyses. The agreement between the two observers was good, but statistically significant differences were found between recordings of the seal in the clinical radiographs and the in vitro radiographs taken in the buccolingual projection. The length of the root filling in each of the three projections was interpreted to be the same, while both inadequate seal and visible lumen apical to the root filling were recorded less frequently in the clinical radiographs than in either of the two in vitro projections. This difference was most pronounced in molar teeth. It was concluded that the lengths of root fillings could be measured correctly in clinical radiographs. Due to the anatomy of root canals in incisors and canines, there was a risk of misinterpreting an inadequate seal as adequate in these teeth. The large amount of tissue surrounding molar teeth tended to cause an underregistration of both inadequate seal and lumen apical to the root fillings in these regions.

Evaluation Studies as Topic↗

PubMed1982

Radiology of the superior segment of the lower lobe: a regional perspective introducing the B6 bronchus sign.

The radiological findings of atelectasis, consolidation, or mass lesions in the superior segment of the lower lobe of the lung (B6 in Boyden's classification) are analyzed. Cases were collected over several years and supplementary series were assembled to study the configurations of the segmental bronchi, the right oblique fissure, and the left pulmonary artery in lateral projection. The upper part of the right oblique fissure could be distinguished from the horizontal fissure on the frontal radiographs by position and angulation; its visualization indicated atelectasis or displacement of the superior segment. Visualization was much less common on the left. Consolidation produced a visible superior segment air bronchogram (the B6 sign) much more often on the left, where the bronchus is usually larger. Orientation and position of the bronchus permit its identification. Other key anatomic landmarks were the descending aorta on frontal radiographs and the posterior margins of the left pulmonary artery and bronchus intermedius on lateral views.

Adult↗

PubMed1977

Characteristics of the Inside-of-the Body Test drawings performed by normal school children.

The Inside-of-the-Body test was administered to an unselected group of 150 elementary school children in Grades 1 to 6. The most frequently identified body part was the heart. Musculoskeletal and visible body parts were identified in younger children. Children in the higher grade levels drew more cavity organs and their drawings more frequently showed the organs in the correct anatomic arrangement. The Inside-of-the-Body test may be a useful adjunctive tool in the psychological assessment of children by identifying the development of internal body perception in normal children as well as those with physical and psychological disorders.

Age Factors↗

PubMedDate not supplied

[Recovery of cervical portio epithelial integrity using radiofrequency: preliminary results].

PURPOSE: The aim of this study was to evaluate the efficacy of the radiosurgical procedure (high frequency, filtered wave-form energy) in the management of benign lesions of uterine cervix. MATERIALS AND METHODS: In a prospective study a radiothermal cautery treatment by micro-needle was performed to 168 women, attending a gynecology office, with an abnormal cervical cytology, istology and with a colposcopic diagnosis of benign cervical lesions with a total visibility of squamous columnar junction and no extended lesion of cervical canal. Cytology and colposcopy were used to follow up after treatment 3-4 months and 10-12 months after the procedure. RESULTS: 130 women (77.6%) obtained a complete recovery at the first follow-up. Partial treatment failure, defined as the persistence or recurrence of a small cervical lesion after three months, was observed in 19 women (18.2%) but after a second treatment in the 100% we obtained a complete recovery with a well visible squamous columnar junction. Radiothermal cautery procedure was advantageous with a shorter duration of surgery, lower cost, reduced operation bleeding, no need for pain-relieving medication and shorter duration of postoperative disability. CONCLUSIONS: This surgical procedure resulted an excellent technique to obtain a complete epithelial recovery of uterine cervix, easy and cheap to be executed in a outpatient office.

Adolescent↗

PubMed2003

Investigation of an image artefact induced by projection noise inhomogeneity in multi-slice helical computed tomography.

The introduction of multi-slice helical computed tomography has fundamentally changed the way radiologists view CT images. Increasing numbers of clinical cases are examined with advanced visualization tools, such as maximum intensity projection, multi-planar reformation and volume rendering. It has been discovered that new image artefacts, which do not appear in the traditional two-dimensional reconstructed images, become visible in images generated by these new tools. In this paper, we investigate the causes of one such artefact, the Venetian blind artefact, which appears as bright-and-dark bands superimposed on three-dimensional images. We demonstrate that such an artefact is caused by the periodical noise variation in the reconstructed images. The image noise variation is, in turn, caused by the interaction of the noise inhomogeneity in the projections with the helical weights. An analytical formula is developed that accurately predicts the presence of such artefacts. Based on our analysis, several approaches are proposed for the artefact reduction or elimination.

Artifacts↗

PubMed2001

Participating dentists' assessment of the pilot regional online videoconferencing in dentistry (PROVIDENT) project.

OBJECTIVE: To assess the educational effectiveness of delivering continuing professional education (CPE) from dental schools to small groups of dentists at distant sites via videoconferenced links using relatively inexpensive equipment and ISDN2 links. DESIGN: 41 videoconferences between the four campuses of London Dental Schools and postgraduate centres in South East England were assessed using a pre-piloted questionnaire which contained open and specific questions. The questionnaire was given to all participants at the end of each videoconference. Answers to the specific questions were graded using the Likert scale. RESULTS: 40 of the 41 videoconferences were completed satisfactorily and were attended by 257 participants, all of whom completed questionnaires. However, no individual question was answered by all the participants. Of the responses 90% were positive on the topics of appropriateness of the teaching material for delivery by videoconference and of its educational level. 90% of responses also indicated a wish to attend further videoconferences and satisfaction at avoiding the need to travel to London for similar educational activity. 87% rated the lecturers as good or excellent in their use of the medium. 85% of responses indicated that the question and answer sessions within the videoconferences were useful and 82% that the visual aids enhanced the sessions. The technical aspects of the videoconferences were rated positively but to a lesser extent than the educational aspects with 69% of positive responses for visibility of visual aids, 54% for sound quality and 76% for the lecturers use of the technology. The technical aspects of the videoconferences improved during the pilot study. In response to the open questions, participants stated that they found the most useful aspects of the videoconferences were not having to travel, access to first rate lecturers, the discussions and the opportunity to interact with experts. CONCLUSIONS: The participants in this pilot study were positive about the use of videoconferencing to deliver educational material from dental schools to small groups. Once the technology has improved, this medium has the potential to provide CPE for dentists at work or at home in response to their specific needs.

Education, Dental, Continuing↗

PubMed1994

The perception of spatial structure with oblique viewing: an explanation for Byzantine perspective?

Earlier work has confirmed that (i) observers can judge divergent receding lines, placed directly in front of them, to be parallel, and (ii) converging lines which are displaced laterally, so that they are viewed obliquely, can also be judged to be parallel. The former observation is in accord with traditional views of perspective while the latter, which is in accord with the depictions of objects found in Byzantine painting, is not in accord with perspective but is predicted by the relative magnitude of the visual angles subtended by the near and far ends of the pair of lines. To investigate whether these effects occurred when the stimulus was clearly three-dimensional, experiments were conducted with a novel apparatus, consisting of a framework of computer-controlled motor-driven luminous rods. This could be remotely adjusted so that all visible sides appeared to be parallel, ie to resemble a cube. Results showed that observers set the sides of this trapezohedron framework as diverging when it was viewed immediately in front of them, a result which is concordant with linear perspective, ie they see the normal projection of a cube as having converging edges. When the framework was displaced from the median plane so that it was viewed obliquely, the sides were set as converging and the magnitude of this effect was significantly related to angle of view, ie observers see the normal projection of a cube as having diverging sides.(ABSTRACT TRUNCATED AT 250 WORDS)

Art↗

PubMed2002

Cone-beam CT with megavoltage beams and an amorphous silicon electronic portal imaging device: potential for verification of radiotherapy of lung cancer.

We investigate the potential of megavoltage (MV) cone-beam CT with an amorphous silicon electronic portal imaging device (EPID) as a tool for patient position verification and tumor/organ motion studies in radiation treatment of lung tumors. We acquire 25 to 200 projection images using a 22 x 29 cm EPID. The acquisition is automatic and requires 7 minutes for 100 projections; it can be synchronized with respiratory gating. From these images, volumetric reconstruction is accomplished with a filtered backprojection in the cone-beam geometry. Several important prereconstruction image corrections, such as detector sag, must be applied. Tests with a contrast phantom indicate that differences in electron density of 2% can be detected with 100 projections, 200 cGy total dose. The contrast-to-noise ratio improves as the number of projections is increased. With 50 projections (100 cGy), high contrast objects are visible, and as few as 25 projections yield images with discernible features. We identify a technique of acquiring projection images with conformal beam apertures, shaped by a multileaf collimator, to reduce the dose to surrounding normal tissue. Tests of this technique on an anthropomorphic phantom demonstrate that a gross tumor volume in the lung can be accurately localized in three dimensions with scans using 88 monitor units. As such, conformal megavoltage cone-beam CT can provide three-dimensional imaging of lung tumors and may be used, for example, in verifying respiratory gated treatments.

Algorithms↗

PubMed1988

[Visibility of the inferior horns in computed tomography of normal subjects and epileptics].

In recent years brain CT scan has been so popular that many investigators have been trying to clarify the normal CT images. But little attention has been paid to the inferior horns of lateral ventricles in spite of their importance for judging mesial temporal lobe structures. The present study was designed to elucidate how the inferior horns were visualized on brain CT in normal subjects from childhood to aged group, and to evaluate whether the inferior horns were dilated in the epileptics or not. The subjects of the present study were 502 normal controls (2-79 y, mean 36.1 y) and 163 epileptic patients with normal CT image (4-68 y, mean 26.6 y) including 55 cases of temporal lobe epileptics. CT scans were performed with EMI 1010 scanner, and slices were obtained every 10 mm from the projection of 5-10 degrees angle for orbito-meatal line. Inferior horns were examined at the level of basal cisterns. Because inferior horns were not necessarily visible in our cases, we examined the frequency of clearly visualized inferior horns at each decade, and regarded their frequency as the size of inferior horns at each decade. In normal controls, frequency of visible inferior horns was relatively high in early childhood, and decreased as they grew. In the 3 rd to 4 th decades the visibility frequency became the lowest (30-35%), and then gradually increased as the subjects became older.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed2002

A contour propagation approach to surface filling-in and volume formation.

A new approach to surface and volume formation is introduced in response to the question, "Why do some silhouettes look 3 dimensional (3D) and others look 2D?" The central idea is that form information can propagate away from a "propagable segment" (PS) of occluding contour that could have projected onto the image from the visible portion of a cross-section of a surface. A key property of a PS is that it exhibits abrupt curvature changes where it meets the rest of the occluding contour. An algorithm is described for filling in curved surfaces from a PS: When copies of a PS are propagated into the interior, they act as cross-sectional surface contours that also exhibit abrupt curvature changes with the rest of the occluding contour. The result is a nonmetric coding of 3D-shape in terms of local ordinal surface curvature and orientation relationships that is scale, translation, and rotation invariant.

Algorithms↗

PubMedDate not supplied

Head holder for PET, CT, and MR studies.

A new head holder for the fixation and repositioning of the patient head in PET, CT, and MR scanners has been designed and tested. With this device, a bidimensional correlation between functional and anatomical brain images can also be obtained. Head fixation and repositioning are achieved using the patient's dental morphology as an anatomical reference. With a dentistic material, a mold of the patient's teeth is obtained in a few minutes. The molding substance rests on a plastic support, fixed to the head holder. Each time the patient undergoes a new study, his/her personal mold is used, ensuring accurate head repositioning. External markers fixed on the head holder (made visible in lateral PET and CT projection images, midsaggital MR images, and also on the axial images) make it possible to record and recognize the angular orientation and the position of the brain in the three-dimensional space, to correlate images of the same patient obtained with different neuroimaging modalities, and to accurately reposition patients for follow-up studies. The head holder was tested on several subjects. Fixation and repositioning accuracy of within 2.5 mm were achieved in the three-dimensional space. Orientation accuracy was 1 degree.

Equipment Design↗

PubMedDate not supplied

The percutaneous columellar strut.

BACKGROUND: Understanding tip support mechanisms is essential for nasal surgery, especially for preservation or augmentation of tip projection. METHODS: Support of the nasal tip often is improved by the use of struts placed between the medial crura. The percutaneous columellar strut is a technique that provides additional tip support during septoplasty and closed rhinoplasty. The strut is placed via a small vertical columellar incision. RESULTS: The advantage of easy and simple insertion outweighs the minor potential disadvantage of a small, visible vertical columellar scar. It is useful in addressing tip ptosis when trauma, surgery, or aging has reduced the contribution of the septum to tip support. CONCLUSION: A detailed description of the percutaneous columellar strut technique and results of its application are presented.

Humans↗

PubMed1998

Nurses as patient-teachers: exploring current expressions of the role.

An exploration of nursing literature reveals a broad acceptance of the role of patient-teacher. While patient-teaching has become widely accepted as part of nursing practice, there is little published evidence to support an assertion of its centrality in current nursing practice. Patient-teaching has been variously described, yet there is evidence of polarity in its construction. This polarity is between a health promotion empowerment framework and a mechanistic-interventionist framework. Further, there is little visible consensus about the scope and boundaries of patient-teaching by nurses. Preliminary findings from a pilot study of nurses' perceptions of patient-teaching reveal tensions created within these contradictory frameworks. Nurses find themselves positioned as paternalistic in their approach to patients and simultaneously subservient to other disciplines in determining the focus of patient-teaching.

Attitude of Health Personnel↗

PubMed1995

Automatic exposure control in retinal laser therapy.

Retinal laser spots are often over- or underexposed due to inhomogeneities of fundus pigmentation or variations in the radiation power impinging on the retina. We developed a method to control the exposure time of each individual spot of retinal laser photocoagulation in real time. The laser light reflected from the spot area is recorded by a detector. The intensity of this light increases during the exposure due to bleaching of the retinal pigment. If the reflected light reaches a predefined level, the laser apparatus is immediately stopped by a computer, which controls the whole process. The procedure was tested in enucleated porcine eyes. After verification of the proper function, a pilot study in a small collective of 19 patients (20 eyes, 25 sessions) with clear optical media was performed. In all cases, the apparatus worked safely. Visible indications for overexposed spots, particularly bleeding in extreme cases, did not occur. However, about 2%-5% of the spots were underexposed, mainly due to eye movements of the patient during the coagulation. Large variations in the automatically controlled exposure time confirm the difficulty in properly adjusting this parameter without such an automatic device. However, to be applicable to patients with opaque optical media, the method must be improved.

Adult↗

PubMed1990

Identification of community leadership in the development of public health education programs.

This paper deals with the identification of community leadership within the context of a community cancer prevention education program. An unusually high age-adjusted black/white mortality ratio exists for cervical cancer in Forsyth County, North Carolina. In response to this problem, a comprehensive public education program dealing with cervical cancer prevention was developed and currently is being implemented. Black community leaders have played an important role in planning for the program and in providing assistance for program implementation. Leaders were identified by means of a modified snowball technique in which ten recognized leaders in the black community initially were contacted and asked to name at least five other leaders in areas of leadership that included social/civic, political, religious, business, and less visible leaders. This process continued until no new names were generated. Interviews were conducted with 103 persons, and 589 leaders were identified. A cohort of 54 top-ranked leaders were identified, and the characteristics of these leaders are presented. The value of the leadership identification process is discussed in terms of (a) the identification process itself, (b) the generation of a list of key individuals who can serve as sources of advice for development and implementation of the program and as the beginning point for dissemination of new information on the project, and (c) a mechanism for development of a sense of community ownership of the project.

Black or African American↗

PubMed2006

Correlation between carotid area calcifications and periodontitis: a retrospective study of digital panoramic radiographic findings in pretreatment cancer patients.

OBJECTIVES: The objective of this study was to examine the prevalence of carotid area calcifications retrospectively detected on digital panoramic radiographs of pretreatment cancer subjects, and to correlate the finding of such calcifications with radiographic evidence of periodontal bone loss in the same subjects. STUDY DESIGN: Digital panoramic radiographs of 201 subjects were evaluated for calcifications projected in the carotid artery bifurcation area as well as for alveolar bone loss as a result of periodontal disease. Inclusion criteria were unobscured carotid artery bifurcation regions bilaterally and sufficient index teeth present with a definable cemento-enamel junction and alveolar crest. Radiographs were independently observed for carotid area calcifications and for periodontal status. Image enhancements permitted for detection of calcifications projected in the carotid area included window/level, inverse, and emboss. Periodontal measurements were made on index teeth using proprietary imaging software and a mouse-driven measurement algorithm. A 3-factor analysis of variance was performed with 3 between-subjects comparisons. Percentage of bone loss was the dependent variable. Independent variables were age, subject sex, and the presence or absence of carotid area calcifications. RESULTS: Differences measured in percentage of bone loss between sexes were not statistically significant. While bone loss did increase with age, comparison of the mean bone loss of each age category revealed no statistical significance. There was a highly significant correlation between carotid artery area calcifications visible on panoramic radiographs and percent alveolar bone loss. Radiographs showing unilateral and bilateral calcifications had a mean percent bone loss of 24.2% +/- 12.6% and 25.7% +/- 13.0% respectively, compared to those with no calcification at 10.4% +/- 9.9%. CONCLUSIONS: Nearly 1 in 4 subjects in this study evidenced calcifications projected in the carotid bifurcation region. The finding of such calcifications was significantly related to the calculated percentage of alveolar bone loss.

Age Factors↗

PubMed2001

The visibility of cancer on previous mammograms in retrospective review.

AIM: To study how many tumours were visible in restrospect on mammograms originally reported as normal or benign in patients coming to surgery with proven breast cancer. The effect of making the pre--operative mammogram available was also assessed. MATERIALS AND METHODS: Three hundred and twenty initial mammograms of consecutive new breast cancer cases were analysed by a group of radiologists in the knowledge that all patients were later diagnosed with breast cancer. The films were read twice, first without and then with the later (pre-operative) mammograms available. The parenchymal density in the location of the tumour was classified as fatty, mixed or dense, and the tumours were classified as visible or not visible. The reasons for the invisibility of the tumour in the earlier examination were analysed. RESULTS: Fourteen per cent (45) of cancers were retrospectively visible in earlier mammograms without the pre-operative mammograms having been shown, and 29% (95) when pre-operative mammograms were shown. Breast parenchymal density decreased with age and the visibility of tumours increased with age. When considered simultaneously, the effect of age (over 55 vs under 55) was greater (OR = 2.9) than the effect of density (fatty vs others) (OR = 1.5). The most common reasons for non-detection were that the lesion was overlooked (55%), diagnosed as benign (33%) or was visible only in one projection (26%). Growing density was the most common (37%) feature of those lesions originally overlooked or regarded as benign. CONCLUSIONS: Tumours are commonly visible in retrospect, but few of them exhibit specific signs of cancer, and are recognized only if they grow or otherwise change. It is not possible to differentiate most of them from normal parenchymal densities. Saarenmaa, I. (2001). Clinical Radiology56, 40-43.

Adult↗