Delivering computationally-intensive digital patient applications to the clinic: An exemplar solution to predict femoral bone strength from CT data

BACKGROUND AND OBJECTIVE

Whilst fragility hip fractures commonly affect elderly people, often causing permanent disability or death, they are rarely addressed in advance through preventive techniques. Quantification of bone strength can help to identify subjects at risk, thus reducing the incidence of fractures in the population. In recent years, researchers have shown that finite element models (FEMs) of the hip joint, derived from computed tomography (CT) images, can predict bone strength more accurately than other techniques currently used in the clinic. The specialised hardware and trained personnel required to perform such analyses, however, limits the widespread adoption of FEMs in clinical contexts. In this manuscript we present CT2S (Computed Tomography To Strength), a system developed in collaboration between The University of Sheffield and Sheffield Teaching Hospitals, designed to streamline access to this complex workflow for clinical end-users.

METHODS

The system relies on XNAT and makes use of custom apps based on open source software. Available through a website, it allows doctors in the healthcare environment to benefit from FE based bone strength estimation without being exposed to the technical aspects, which are concealed behind a user-friendly interface. Clinicians request the analysis of CT scans of a patient through the website. Using XNAT functionality, the anonymised images are automatically transferred to the University research facility, where an operator processes them and estimates the bone strength through FEM using a combination of open source and commercial software. Following the analysis, the doctor is provided with the results in a structured report.

RESULTS

The platform, currently available for research purposes, has been deployed and fully tested in Sheffield, UK. The entire analysis requires processing times ranging from 3.5 to 8 h, depending on the available computational power.

CONCLUSIONS

The short processing time makes the system compatible with current clinical workflows. The use of open source software and the accurate description of the workflow given here facilitates the deployment in other centres.

Validation of Quantitative Light-Induced Fluorescence for Quantifying Calculus on Dogs' Teeth

Periodontal disease is a common disease of dogs and is initiated by the buildup of plaque on the tooth surface. As plaque matures, it becomes mineralized to form calculus, which although not directly involved in the etiology of periodontal disease, provides an irregular surface to which plaque can adhere. Evaluation of the quantity of plaque and calculus on dogs' teeth is therefore essential to enable the efficacy of products, designed to prevent or retard plaque and calculus accumulation, to be evaluated. The objective of this study was to determine whether quantitative light-induced fluorescence (QLF^TM) is a suitable tool to quantify the amount of calculus on the buccal surface of dogs' teeth following the removal of disclosed plaque by tooth brushing. The amount of calculus on the teeth of 26 miniature schnauzers was measured, using QLF and a calculus index method (Warrick-Gorrel), during a 28-day phase crossover study comparing feeding a daily dental chew versus providing no daily chew. Quantification of calculus using the Warrick-Gorrel method showed a 43.8% reduction in calculus buildup, with 95% confidence interval of 27.3 to 60.3 ( P < .001). With QLF, the percentage reduction in calculus accumulation was 65.8% (58.1-73.4, P < .001). A retrospective sample size analysis showed that fewer dogs were required for QLF analysis compared to the Warrick-Gorrel method. This study demonstrated that QLF is a sensitive and precise method for quantification of calculus on dogs' teeth. It removes the subjective element of human examiners and has greater accuracy and reduced variability through the continuous nature of the data.

Quantification of Canine Dental Plaque Using Quantitative Light-Induced Fluorescence

The aim of this work was to evaluate Quantitative Light-induced Fluorescence (QLFTM) as an alternative to the established Logan and Boyce method for determining plaque coverage of dogs’ teeth. In a series of studies in conscious and anesthetized dogs, QLF showed good intra-photographer repeatability (coefficient of variation [CV] of 7.5% for undisclosed teeth) and inter-photographer reproducibility (CV of 3.2% for undisclosed teeth and 8.5% for disclosed teeth). The QLF software accurately identifies areas of plaque as demonstrated by comparison to the variability of 5 human scorers, manually marking plaque on QLF-acquired images ( P = 0.1). There was good agreement with the modified Logan and Boyce method in the percentage reduction in plaque accumulation measured when dogs were fed an oral care chew versus no chew. To see a 15% difference in plaque accumulation, which is considered sufficient by the Veterinary Oral Health Council to differentiate between 2 treatments, a retrospective power analysis (90%) of the data established that only 7 dogs would be required, compared to 19 dogs for the modified Logan and Boyce method. QLF is a reliable method for measuring dental plaque in dogs with the added advantage that it is not subjective and requires fewer animals.

A Pyrosequencing Investigation of Differences in the Feline Subgingival Microbiota in Health, Gingivitis and Mild Periodontitis

Periodontitis is the most frequently diagnosed health problem in cats yet little is known about the bacterial species important for the disease. The objective of this study was to identify bacterial species associated with health, gingivitis or mild periodontitis (<25% attachment loss) in feline plaque. Knowledge of these species is a first step in understanding the potential for improving oral health of cats via dietary interventions that alter the proportions of influential species. Subgingival plaque samples were collected from 92 cats with healthy gingiva, gingivitis or mild periodontitis. Pyrosequencing of the V1-V3 region of the 16S rDNA from these plaque samples generated more than one million reads and identified a total of 267 operational taxonomic units after bioinformatic and statistical analysis. Porphyromonas was the most abundant genus in all gingival health categories, particularly in health along with Moraxella and Fusobacteria. The Peptostreptococcaceae were the most abundant family in gingivitis and mild periodontitis. Logistic regression analysis identified species from various genera that were significantly associated with health, gingivitis or mild periodontitis. The species identified were very similar to those observed in canine plaque in the corresponding health and disease states. Such similarities were not observed between cat and human at the bacterial species level but with disease progression similarities did emerge at the phylum level. This suggests that interventions targeted at human pathogenic species will not be effective for use in cats but there is more potential for commonalities in interventions for cats and dogs.

A survey in the West Midlands on the use of the courtesy title 'Dr' by UK dental practitioners

OBJECTIVE

To assess the 1995 General Dental Council's decision to remove restrictions on GDPs using the courtesy title 'Dr'.

METHODS

In 1996 this survey undertook a qualitative analysis of the views of four groups involved in primary dental care: 72 GDPs, 25 medical practitioners, 46 vocational dental practitioners, 89 patients.

RESULTS

These indicated that some respondents thought that there would possibly be better quality of patient care due to improved medical history taking, that the public's image of the dental profession might be enhanced and that 87% of newly qualified dentists were in favour of the use of the title 'Dr'.

CONCLUSIONS

Use of the title appears to be on the increase and if use of the title does become widespread, then all practitioners will need to re-evaluate their choice of personal titles. GDPs need to consider if using the title 'Dr' will encourage patients to give more detailed medical histories.

Survey of the use of personal protective equipment and prevalence of work related symptoms among dental staff

OBJECTIVES

Dental instruments such as the right angle or straight handpiece, air turbine, and ultrasonic scaler have the ability to produce dental aerosols containing water, saliva, microorganisms, blood, tooth particles, lubricating oil, and restorative materials. The purpose of this study was to find out whether personal protective equipment (mask, glasses) was used by dental personnel, and to investigate possible work related disease in the dental profession.

METHODS

Cross sectional data were collected with a self administered questionnaire sent to 69 randomly chosen general dental practices in the West Midlands Region. All members of the dental team completed questionnaires (dentists (n = 122); nurses (n = 115); hygienists (n = 86); and receptionists (n = 74) and answered questions on use of personal protective equipment and the prevalence of upper and lower respiratory tract, eye, and skin symptoms (reported and work related). Reception staff were included as a low exposure, control group. Also, a longitudinal study of dental hygienists was carried out on 31 people who had taken part in a similar study five years earlier.

RESULTS

Use of a face mask and glasses differed between clinical groups with hygienists and nurses being the most and least prevalent users respectively. Although several reported symptoms were significantly more prevalent among clinical staff, only one work related symptom (skin rashes or itchy or dry skin) was reported by the clinical staff more than by the non-clinical receptionists. Among female clinical staff, age < 35 years and atopy were the factors that predisposed to work related symptoms. Also, reported symptoms were related to duration of use of instruments that generated aerosols.

CONCLUSIONS

This study shows a low level of work related symptoms in dentistry, but highlights a group vulnerable to prolonged exposures to dental aerosols. It also supports the need for enforcement of the use of personal protective equipment among dental nurses.

The vocational training scheme: decision-making in relation to general dental practitioners participating as scheme trainers

In recent years, well-documented changes have occurred in the patterns of oral disease and, as a result, the scope and complexity of dental treatments has widened considerably. In response to this the Department of Health has introduced a compulsory one-year postgraduate vocational training scheme [VTS]. In this scheme, new graduates spend time in approved general dental practices, trained by selected general dental practitioners [GDPs] who are seen as having 'best practice' standards. For the VTS to succeed it will require the continued support of these 'best quality' GDPs who at the moment are competing for places as trainers. Such competition has not always existed and this paper describes a decision-making model for trainers which was developed because future external influences could reverse this competitive scenario, with a major effect on the postgraduate training programme.

Safety in the presence of lightning

Not enough emphasis is usually placed on the proactive ability to recognize the lightning hazard. Instead, most literature and training materials treat the reactive mode. The latter approach emphasizes the posture to take when a person is caught by surprise in the open by a thunderstorm when the lightning threat is at its greatest; in other words, it is too late for precautions. The same reactive approach concentrates on what a person is wearing or holding when lightning is overhead instead of how the person came to be in this situation in the first place. Rather than focusing on these last-minute factors, the primary issue must be on the ability of a person, whether in a baseball game, riding a bike, or on a golf course, to recognize in advance the existence of a major lightning threat. This proactive approach emphasizes advance planning and recognition of a potential threat from lightning. A complete plan involves a sequence of decisions on a time scale from days to seconds. Although most of the available information in pamphlets and safety guidelines is correct concerning the reactive phase of lightning safety, the hazard remains important because of the lack of emphasis on planning and awareness.