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Biomedical subjects

V E Rushton

Publications and source records attributed to V E Rushton.

At least 19 recordsLinked to original sources
PubMed2005

A laboratory comparison of three imaging systems for image quality and radiation exposure characteristics.

AIM: To measure and compare the relationships between image quality and X-ray exposure for three types of intraoral imaging system (conventional film, phosphor plate system and CCD-based system). METHODOLOGY: Kodak 'Insight' F-speed film, Digora FMX (phosphor plate system) and Visualix USB (CCD system) were used to produce series of radiographic images of two tooth-bearing jaw specimens (maxillary molar and mandibular molar regions) at a range of X-ray exposures from 10 ms to 2000 ms (all at 6 mA and 60 kV). Digital images were viewed from a computer monitor and films viewed on a conventional light box. Five observers scored each image using a five-point subjective image quality scale (0-4). RESULTS: Optimum image quality (4) was seen for conventional film. Neither digital system achieved this score at any exposure, achieving in both cases a maximum mean score of 3.1 (adequate visualization). The two digital systems, however, provided adequate visualization at substantially lower exposure times. Dose reduction over conventional film for maximum quality images with Visualix USB was 20%, but for Digora FMX it was 70%. All three systems gave acceptable (quality score of two or higher) images over a broad range of exposures. CONCLUSIONS: In terms of subjective image quality, F-speed film performed better than the two digital systems, but this must be weighed against the ability of the two digital systems to give adequate image quality at lower radiation doses.

Humans↗
PubMed2005

The effectiveness of undergraduate teaching of the identification of radiographic film faults.

OBJECTIVES: To see if there were any differences in the ability of final year dental students at two UK dental schools, who were within 4 months of graduation, to identify radiographic film faults. METHODS: The two groups of undergraduates were shown 11 dental radiographs using a slide format. The 11 radiographs included 8 films with film faults, 2 films without technical or processing errors and a film with minimal faults. Each student was asked to assess each film for the presence/absence of film fault(s), to detail how to correct the fault (if appropriate) and to give a subjective quality rating of each film. RESULTS: The range of marks obtained by both groups of students was low. All students found the identification of panoramic film faults more challenging than faults associated with intraoral films. 15% of students from University B scored more than half the possible marks compared with 2% from University A. CONCLUSIONS: Both groups of students had the necessary knowledge of how to correct faults once identified. However, the marked difference in competency in identifying faults between the two groups of students has implications for the future teaching and development of the radiology curriculum.

Chi-Square Distribution↗
PubMed2005

Salivary otorrhoea: a case report and a review of the literature.

This report presents an unusual case of spontaneous salivary otorrhoea in which advanced imaging was used to identify a developmental defect in the anterior wall of the bony external auditory meatus. This defect, the so-called foramen of Huschke, was subsequently found to be the source of the fistula. A review of the literature highlights the diagnostic dilemmas that such cases pose for the clinician.

Ear Canal↗
PubMed2004

Does the procedure of arthrography affect the range of movement in patients with locking of the temporomandibular joint?

The aim of this study was to investigate whether arthrography itself altered the range of mandibular movements, in a group of patients with locking of the temporomandibular joint (TMJ). The clinical records of a series of 161 patients who were diagnosed with locking of the TMJ were retrospectively analysed. Mouth opening had improved in 57 out of 161 patients (35%). Twenty-three patients (14%) had improved by 5 mm or less. Nineteen patients (11%) had improved by more than 5 mm but less than 10 mm, whereas 15 patients (9%) had improved by more than 10 mm. Of the patients who experienced an improved mouth opening, only nine (15%) had improved from their pre-arthrography restricted maximum opening to beyond the lower limit of normal. This suggests that the injection of contrast medium had an effect on the range of vertical opening in patients with displacement of the disc without reduction.

Adolescent↗
PubMed2002

Screening panoramic radiography of new adult patients: diagnostic yield when combined with bitewing radiography and identification of selection criteria.

OBJECTIVES: To measure the radiological diagnostic yield on screening panoramic radiographs taken of new adult patients and to identify selection criteria for panoramic radiography of new adult patients. DESIGN: Survey of 1,817 consecutive panoramic radiographs taken as 'routine' on new patients with statistical analysis of clinical and radiological findings. SETTING: All radiographs were obtained from 41 general dental practitioners (GDPs). The GDPs provided the clinical information about the patient obtained by history and examination. Collection of material occurred in 1998/1999. MATERIALS AND METHODS: Two dental radiologists recorded the radiological findings on each of 1,817 panoramic radiographs by consensus. Those findings that would have been identified from bilateral posterior bitewing radiographs of each patient were then excluded to give modified figures for radiological findings. MAIN OUTCOME MEASURES: Indices of diagnostic yield were devised and calculated for each radiograph from the data on radiological findings. Total diagnostic yield (DY) and modified diagnostic yield (MDY), after exclusion of findings identifiable on bitewing radiographs, were both calculated. Clinical indicators of a high MDY were identified using stepwise multiple regression analysis. RESULTS: MDY was 0 for 17% of the radiographs (all patients) and 23% of the radiographs when the asymptomatic group were considered. The clinical variables for which the significance was high (p < 0.001) were: increasing number of teeth with clinical suspicion of periapical pathology, presence of partially erupted teeth, increasing number of clinically evident carious lesions, partially dentate status and presence of crowns. CONCLUSION: Taking posterior bitewing radiographs of new adult patients would reduce the diagnostic yield identified solely by panoramic radiography. Using clinical factors derived from the history and examination as radiographic selection criteria modestly improves the odds of achieving a high diagnostic yield from panoramic radiography.

Adult↗
PubMed2002

Routine panoramic radiography of new adult patients in general dental practice: relevance of diagnostic yield to treatment and identification of radiographic selection criteria.

OBJECTIVES: We sought to measure the diagnostic yield of relevance to treatment on routine panoramic radiographs taken of new adult (ie, 18 years and over) patients in general dental practice. STUDY DESIGN: Routine panoramic radiographs (n = 1817) obtained from general dental practice were assessed and radiologic yield recorded using consensus viewing by 2 dental radiologists. A modified diagnostic yield of relevance to treatment for each radiograph was calculated by omission of findings that would have been identified on bilateral posterior bitewing radiographs and of radiologic findings of no relevance to treatment. Stepwise logistic regression analysis was used in attempt to identify clinical indicators of a high diagnostic yield of relevance to treatment. RESULTS: The diagnostic yield of relevance to treatment was zero for the majority (56%) of patients. This figure rose to 71% when the symptom-free patients were considered. Five clinical indicators for panoramic radiography were identified, as follows: clinical suspicion of teeth with periapical pathologic conditions, presence of partially erupted teeth, clinically evident caries lesions, swelling, and clinically suspected unerupted teeth. CONCLUSION: Routine panoramic radiography of adult dental patients is not supported by the results of this study. The use of clinical indicators to select patients may help to improve diagnostic yield.

Adult↗
PubMed2001

Screening panoramic radiology of adults in general dental practice: radiological findings.

AIM: To identify the radiological findings from routine screening panoramic radiographs taken of adult (> or = 18 years) patients in general dental practice. METHOD: Forty-one general dental practitioners (GDPs) who routinely took panoramic radiographs of all new adult patients were recruited. In total, they submitted 1,818 panoramic radiographs of consecutive patients along with basic patient information, radiological reports and treatment plans. The radiographs were also reported by 'experts' (consensus of two dental radiologists). Radiological findings were recorded from the GDP assessments (dentist RY), the experts (expert RY), after exclusion of findings that would have been seen on posterior bitewing radiographs (MRY) and after exclusion of findings of no relevance to treatment (MRYT). RESULTS: There was no significant difference in age profile between the study sample and Dental Practice Board population figures (P = 0.26). No radiographs other than the panoramic radiograph had been taken for 57.1% of patients. For the GDP assessments, only 4.6% of patients had radiographs with no radiological findings, while for the experts this proportion was 3.1%. With the exception of the assessment of periodontal bone loss, the experts diagnosed significantly greater proportions of cases as having positive radiological findings. Agreement between dentist and expert assessments varied greatly. When findings from bitewing radiographs were excluded, no radiological findings were recorded on the radiographs of 17.2% of patients. When proposed treatment plans were taken into account, the majority of patients' radiographs (56.3%) had no radiological findings of relevance to treatment. CONCLUSIONS: The choice of radiographic examination for the majority of patients in the study did not follow current guidelines. Dentists diagnosed fewer abnormalities than did experts. While many radiological findings are revealed by panoramic radiography, these may either duplicate information from bitewing radiographs or are often of no significance to treatment planning. This study did not provide evidence to support the practice of routine panoramic radiography of all new adult patients.

Adult↗
PubMed2000

The influence of viewing conditions on radiological diagnosis of periapical inflammation.

OBJECTIVES: To determine the effect of viewing conditions upon diagnosis of early periapical inflammatory pathosis on intra-oral radiographs, and to examine the effect of observer experience upon diagnostic performance in this task. METHODS: 50 observers examined 18 periapical radiographs using three different viewing conditions (room lighting; viewing box; viewing box with x2 magnification and masking). Their diagnoses were compared with an 'expert' diagnosis provided by repeated viewings of the films by two dental radiologists. Sensitivities and specificities were determined. RESULTS: When 'ideal' viewing conditions were used, optimal sensitivity (78%) and specificity (78%) were obtained. Use of a viewing box was associated with significantly higher specificity than the use of room lighting (P = 0.0016). Use of masking and x2 magnification was associated with significantly higher sensitivity than a viewing box alone (P = 0.004). There were few significant differences in diagnostic performance between observers, but qualified dental staff had significantly higher specificities than 4th year (P = 0.01) and 5th year (P = 0.01) students when a viewing box was used alone. CONCLUSIONS: This study on early periapical inflammatory pathosis gives support to guidelines which recommend the use of a viewing box, x2 magnification and masking for interpreting intra-oral radiographs. It also suggests that observer experience may influence interpretation of early periapical pathosis.

Clinical Competence↗
PubMed1999

The quality of panoramic radiographs in a sample of general dental practices.

OBJECTIVE: To assess the quality of panoramic radiographs in a sample of general dental practices, to determine the relative frequency of errors and to identify those errors directly responsible for diagnostically inadequate images. MATERIALS AND METHODS: Examination of 1,813 panoramic radiographs obtained from 41 general dental practitioners and recording of faults. The study was carried out in 1998. Radiographs were judged as being 'excellent', 'diagnostically acceptable' or 'unacceptable'. RESULTS: Only 0.8% of films were 'excellent', 66.2% were 'diagnostically acceptable' and 33% were 'unacceptable'. The most common faults which directly contributed to failure of the radiographs were antero-posterior positioning errors, low density and low contrast. CONCLUSIONS: The quality of panoramic radiographs was considerably lower than standards recently set for primary dental care. The quality of panoramic radiography could be improved by careful attention to radiographic technique and processing.

Adolescent↗
PubMed1999

Canalis sinuosus mimicking a periapical inflammatory lesion.

A case is presented in which an anatomical feature, canalis sinuosus, manifested as a periapical radiolucency on an upper canine. This may have been interpreted as an inflammatory lesion and led to the patient receiving inappropriate treatment had a further radiograph not been taken. The incisive foramen and mental foramen are well known anatomical features which may mimic periapical inflammatory lesions but it is less common for a neurovascular canal to manifest as a periapical radiolucency on an upper canine.

Adult↗
PubMed1999

Aspects of panoramic radiography in general dental practice.

OBJECTIVES: To gather information on the types of panoramic x-ray equipment used in NHS dental practice and whether dentists satisfy the legal requirements for safety, to determine which practice personnel take panoramic radiographs and to assess the prevalence of the practice of 'routine' panoramic radiography among NHS dentists. DESIGN: Postal questionnaire survey of general dental practitioners carried out during 1997 in selected FHSAs in England and Wales. RESULTS: 542 dentists returned the questionnaire, a 73.3% response. Panoramic x-ray equipment ranged in age from 27 years old to new, with 42.2% exceeding 10 years in age. The overwhelming majority of GDPs satisfied the requirement for regular maintenance and surveying of equipment. Almost all dentists (95.9%) performed a history and clinical examination prior to panoramic radiography but 42% practised 'routine screening' of new adult patients. A substantial proportion (36.7%) of dentists used unqualified personnel to take panoramic radiographs. CONCLUSIONS: While some aspects of this study give reassurance about the prevalence of good practice, widespread panoramic screening and using unqualified staff to take radiographs causes concern. These findings have implications for educators and for those involved in maintaining clinical standards.

Adult↗
PubMed1999

Factors influencing the selection of panoramic radiography in general dental practice.

OBJECTIVES: To identify factors influencing dentists' decisions to take panoramic radiographs and to determine dentists' perceptions of the value of panoramic radiographs in the diagnosis of common dental pathologies. METHODS: Questionnaire of dentists with access to panoramic radiography equipment in 22 randomly selected Family Health Service Authorities in England and Wales. Dentists were asked to score 17 factors for their influence upon panoramic use, compare the relative diagnostic value of panoramic and intraoral radiographs for diagnosis of common dental pathologies and state their principal reasons for taking panoramic radiographs. RESULTS: The response rate to the questionnaire was 73.3%. The factors most likely to influence dentists to take a panoramic radiograph were 'planning oral surgery', 'facial trauma', 'periodontal disease', 'heavily restored dentition' and 'patient first attendance'. Dentists' opinions on the diagnostic usefulness of panoramic radiographs were in broad agreement with those in the scientific literature. The main reasons for taking panoramic radiographs were as a 'general screen' and as a 'view for unerupted or impacted teeth'. CONCLUSIONS: There are areas where dentists' prescription of panoramic radiographs is in disagreement with recent guidelines. Successful implementation of these guidelines would be likely to lead to a substantial reduction in the numbers of panoramic radiographs taken by GDPs.

Adult↗
PubMed1996

The potential medico-legal implications of computed radiography.

Computed radiographic (CR) systems are available which allow dentists to obtain direct digital intra-oral images. These CR images, however, can be readily altered using image processing software. This paper demonstrates the potential medico-legal problems of image manipulation and calls for manufacturers of CR equipment to be pressed to explore methods of preventing such abuse.

Computer Security↗
PubMed1996

The use of panoramic radiology in dental practice.

OBJECTIVES: Approximately 1.5 million panoramic radiographs are taken annually in the general dental service in England and Wales. The aim of this review was to assess the clinical role of panoramic radiology in the diagnosis of diseases associated with the teeth and to consider its value in routine screening of patients. METHOD: This was carried out by critical review of the literature. RESULTS: In addition to common problems with radiographic technique and processing, there are limitations in image quality inherent to panoramic radiology. These factors contribute to a reduced diagnostic accuracy for caries diagnosis, demonstration of periodontal bone support and periapical pathology when compared with intraoral radiography. Routine screening is unproductive for large proportions of dentate and edentulous populations, while in those cases where pathology is detected the diagnostic accuracy can be questioned. Furthermore, the "detection' of asymptomatic anomalies may have no effect on patient management. Attempts to develop and test panoramic radiographic selection criteria are reviewed. CONCLUSIONS: New, high-yield selection criteria for panoramic radiography are proposed as a means of reducing unnecessary examinations, limiting radiation doses and reducing financial costs to patients and health service providers. However, research is indicated to develop further and to test such selection criteria.

Alveolar Bone Loss↗
PubMed1996

A two-centre study to determine dentists' agreement with current guidelines on the frequency of bitewing radiography.

The main aim of this study was to compare the intervals between initial and recall bitewing radiography recommended by general dental practitioners (GDPs) with those advocated in published guidelines. A questionnaire containing eight clinical scenarios was distributed to GDPs in two areas of England, Birmingham (fluoridated) and Manchester (non-fluoridated). The response rate was 70.8%. There was considerable agreement (> 66.0%) with recommended guidelines for all low caries risk scenarios, but in three out of the four high caries risk scenarios a minority of dentists were in agreement (< 49.5%). In high caries risk scenarios there was a tendency to over prescription with adult patients and under-prescription for patients in the mixed dentition. For all low risk scenarios except the youngest patient, there was a significantly greater agreement with the guidelines amongst Birmingham dentists, with the Manchester group having a greater tendency to over-prescription. This difference may be related to the effects of fluoridation of the water supply in the Birmingham area. There was generally greater agreement with the guidelines amongst younger dentists, with their older colleagues tending to under-prescription. The results suggest that greater emphasis on selection criteria in continuing education of dentists is required.

Adolescent↗
PubMed1996

Factors influencing the frequency of bitewing radiography in general dental practice.

The aim of this study was to determine the influence of a range of patient and dentist factors on the prescription of bitewing radiography. A postal questionnaire of general dental practitioners working in the Birmingham and Manchester areas of England was used. Dentists were requested to score the influence of 15 factors upon their decision whether or not to take bitewing radiographs. Some of these factors were chosen to represent accepted "high caries risk" factors, some "low risk" factors, while others were chosen as they should be irrelevant to prescription of bitewing radiographs. There was a questionnaire response of 70.8%. Dentists recognized accepted high caries risk factors as being an indicator for bitewing radiography but the influence of low caries risk factors was less clear. Only "good oral hygiene" and the presence of "few restorations" were perceived as relevant to bitewing prescription, while fissure sealants were seen as an influence in favour of radiography by almost one third of dentists. Dentists tended to be influenced in their radiographic practice by the opinions of patients and fears of medico-legal consequences. Pregnancy was seen as contra-indicatory for bitewings by almost all dentists. These results suggest that greater emphasis should be placed upon radiographic selection criteria in dental education.

Adult↗