Coronary calcification in the diagnosis of coronary artery disease.

Clinical, postmortem and angiographic studies of coronary calcification are reviewed to define the value of fluoroscopy in the diagnosis and management of coronary artery disease. Autopsy studies consistently show a unique association between calcification of the coronary arteries and atherosclerosis. The relation of coronary calcification to the presence of major stenosis is more variable but is strong enough to be of clinical value, particularly in the younger subject. The diagnostic value of fluoroscopy can be improved by attention to the detailed features of calcification observed with the technique. Combined use of fluoroscopy and exercise testing appears to be a valid and as yet unexploited approach to the noninvasive diagnosis of coronary stenosis. Fluoroscopy has been a neglected method of noninvasive diagnosis and is sufficiently promising to warrant greater clinical use.     

A method to reduce interproximal overlapping and improve reproducibility of bitewing radiographs for use in clinical trials

To improve the quality of bitewing radiographs a Bite Registration Technique (BRT) was developed by modifying a commercially available Rinn XCP Instrument. The modification involved using a rubber impression material to register the subject's bite so that the subsequent replacement of the instrument in the mouth was guided by the registration indentations. A total of 240 radiographs were analysed to determine the frequency and severity of the overlapping and the degree of deviation in the horizontal angulation between the subsequent films. Approximately half the films were taken with BRT and the other half were taken with the unaltered Rinn SCP Instrument (without BRT). Two radiographs were taken of each side of the mouth. Only 11.6% of the proximal surfaces had more than half the enamel overlapped 'with BRT' compared with 33% 'without BRT'. In addition, when using the BRT, the initial and the subsequent radiographs of each child were more alike than 'without BRT'. Ninety percent were virtually identical; the mean difference in width of the largest overlap between the two films was 0.11 mm. To check the validity of these findings, 100 radiographs from a previously published clinical trial which used similar aged children and also used a Rinn SCP Instrument (modified), were analysed used the same criteria. The results obtained were similar to the 'without BRT' results; 30% of the proximal surfaces had more than half the enamel overlapped. Improved accuracy allowed a narrower X-ray beam to be used, thus reducing patient irradiation. The use of the Bite Registration Technique is recommended when a high degree of diagnostic accuracy is desired in clinical trials involving primary dentitions.     

Errors on dental bitewing radiographs

The prevalence of common errors on posterior bitewing radiographs was assessed on 2409 pairs of films collected from different public dental clinics in the county of Buskerud, Norway. Only 4.6% fulfilled the criteria for correct bitewing radiographs. Incorrect position of the film was found in 42.7%. Exposures with wrong horizontal angulation of the central beam constituted 10.6%, and under/overaxial exposures 2.2%, of the sample. Cone cutting occurred in 4.3%. Disturbing spots were found on most of the films (88.1%); 7.7% of the films had been insufficiently washed. Other errors due to wrong darkroom procedures or equipment failures were more rarely observed. The present study has shown that unnecessary errors, reducing the readability of bitewing radiographs, are frequently found. Steps should be taken to improve the standard of the radiographs used for diagnosis.     

Arteriovenous malformation with middle cranial fossa expansion a previously unrecorded association

Summary A large temporal arteriovenous malformation with expansion of the middle fossa is described. This previously unreported association is discussed in relation to the possible aetiology.     

Applying a statistical PTB detection procedure to complement the gold standard

This paper investigates a novel statistical discrimination procedure to detect PTB when the gold standard requirement is taken into consideration. Archived data were used to establish two groups of patients which are the control and test group. The control group was used to develop the statistical discrimination procedure using four vectors of wavelet coefficients as feature vectors for the detection of pulmonary tuberculosis (PTB), lung cancer (LC), and normal lung (NL). This discrimination procedure was investigated using the test group where the number of sputum positive and sputum negative cases that were correctly classified as PTB cases were noted. The proposed statistical discrimination method is able to detect PTB patients and LC with high true positive fraction. The method is also able to detect PTB patients that are sputum negative and therefore may be used as a complement to the gold standard.     

The use of cone-beam computed tomography and digital periapical radiographs to diagnose root perforations

Introduction

The aim of this study was to compare the sensitivity and specificity of cone-beam computed tomography (CBCT) scans and digital periapical radiographs (PR) in detecting strip and root perforations after root canal treatment in mandibular molars.

Methods

Forty-five curved mesial roots were endodontically prepared. Fifteen roots were perforated in the mesiolingual canal by inserting a rotary file through the canal curvature penetrating the root surface (“root perforation”), and 15 roots were perforated with a drill in the axial aspect of the canal (“strip perforation”). Fifteen roots were not perforated. All mesial roots were filled with gutta-percha and AH26. Teeth were then placed in human mandibles. PRs from two angulations and CBCT scans were evaluated by two observers. The sensitivity and specificity of both methods to diagnose perforations were calculated.

Results

The sensitivity and specificity of CBCT scans in the detection of strip perforations were 0.50 and 0.97, respectively, and with two-angled PRs they were 0.13 and 0.97. For the detection of root perforations, the sensitivity and specificity of CBCT scans were 0.86 and 0.70, respectively, and for PRs they were 0.66 and 0.90. The difference between PRs and CBCT scans in detecting strip perforations was significant (chi-square test, P < .05).

Conclusions

The risk to misdiagnose strip perforations was high with both methods, but CBCT scans showed a significant higher sensitivity than PR. There was no significant difference between the methods for the detection of root perforations.     

How do clinical features help identify paediatric patients with fractures following blunt wrist trauma?

Objective

Wrist injuries are a common presentation to the emergency department (ED). There are no validated decision rules to help clinicians evaluate paediatric wrist trauma. This study aimed to identify which clinical features are diagnostically useful in deciding the need for a wrist radiograph, and then to develop a clinical decision rule.

Methods

This prospective cohort study was carried out in the ED of Sheffield Children''s Hospital. Eligible patients were recruited if presenting within 72 hours following blunt wrist trauma. A standardised data collection form was completed for all patients. The outcome measure was the presence or absence of a fracture. Univariate analysis was performed with the χ² test. Associated variables (p<0.2) were entered into a multivariate model. Classification and regression tree (CART) analysis was used to derive the clinical decision rule.

Results

In total, 227 patients were recruited and 106 children were diagnosed with fractures (47%). Of 10 clinical features analysed, six were found by univariate analysis to be associated with a fracture. CART analysis identified the presence of radial tenderness, focal swelling, or an abnormal supination/pronation as the best discriminatory features. Cross fold validation of this decision rule had a sensitivity of 99.1% (95% confidence interval 94.8% to 100%) and a specificity of 24.0% (17.2% to 32.3%). The radiography rate would be 87%.

Conclusions

Radial tenderness, focal swelling, and abnormal supination/pronation are associated with wrist fractures in children. The clinical decision rule derived from these features had a high sensitivity, but low specificity, and would not substantially alter our current radiography rate. The potential for a clinical decision rule for paediatric wrist trauma appears limited.     

久居高原健康居民重返平原后心电图变化的观察

目的:研究久居高原居民重返平原后心电图(ECG)的变化,了解其脱离高原环境后右心室占优势的情况是否得到扭转.方法:对240名久居高原(海拔2261m～4200m)健康居民(年龄50岁～84岁)重返平原后进行了ECG检查,主要测定了右心室电压,并对右心室肥厚(RVH)作出诊断.同时与197名平原同龄人进行了对比.结果:返...