Digital radiographic imaging systems, such as those using photostimulable storage phosphor, amorphous selenium, amorphous silicon, CCD, and MOSFET technology, can produce adequate image quality over ...a much broader range of exposure levels than that of screen/film imaging systems. In screen/film imaging, the final image brightness and contrast are indicative of over- and underexposure. In digital imaging, brightness and contrast are often determined entirely by digital postprocessing of the acquired image data. Overexposure and underexposures are not readily recognizable. As a result, patient dose has a tendency to gradually increase over time after a department converts from screen/film-based imaging to digital radiographic imaging. The purpose of this report is to recommend a standard indicator which reflects the radiation exposure that is incident on a detector after every exposure event and that reflects the noise levels present in the image data. The intent is to facilitate the production of consistent, high quality digital radiographic images at acceptable patient doses. This should be based not on image optical density or brightness but on feedback regarding the detector exposure provided and actively monitored by the imaging system. A standard beam calibration condition is recommended that is based on RQA5 but uses filtration materials that are commonly available and simple to use. Recommendations on clinical implementation of the indices to control image quality and patient dose are derived from historical tolerance limits and presented as guidelines.
Category:
Midfoot/Forefoot; Other
Introduction/Purpose:
While lengthening of the lateral column through a calcaneal neck osteotomy is an integral component of flatfoot reconstruction in younger ...patients with flexible planovalgus deformities, the procedure has been implicated in iatrogenic calcaneocuboid (CC) subluxation and subsequent degenerative changes at the CC articulation. The purpose of this study is to characterize alterations at the CC joint following lateral column lengthening (LCL) as well as to determine if Steinman pin stabilization of the CC joint prior to distraction maintains a normal CC relationship.
Methods:
Seven matched pairs of fresh frozen cadaveric feet underwent pre-procedure plain radiography and cross-sectional computed tomography (CT) imaging. LCL via a calcaneal neck osteotomy was then performed. One foot of each matched pair had a single smooth Steinman pin placed centrally across the CC joint prior to osteotomy distraction. Distraction across each osteotomy was then performed and maintained with a 12mm porous titanium wedge. Repeat imaging was obtained and compared to pre-procedure studies to quantify sagittal and rotational differences at the CC articulation
Results:
Following LCL, plain radiography demonstrated statistically significant increases in the percentage of the calcaneal articular surface dorsal to the superior aspect of the cuboid in both the pinned (8.2% vs 17.6%, p=0.02) and unpinned (12.5% vs 16.3%, p=0.04) specimens. No difference in the percentage of subluxation was found between the two groups following LCL. CT imaging demonstrated statistically significant increases in rotation between the calcaneus and cuboid following LCL in both the pinned (7.6O +- 5.6O, p=0.01) and unpinned (17O +- 12.3O, p=0.01) specimens. Though a greater degree of rotation was present in the unpinned specimens following LCL, this difference was not statistically significant (p=0.28).
Conclusion:
Both sagittal and rotatory subluxation seem to occur at the CC joint following LCL regardless of pin stabilization. As a single pin would be expected to limit pure translation while having little effect on rotation, it is possible that the rotational changes identified on three-dimensional imaging are interpreted as dorsal translation when viewed two dimensionally using plain radiography. Consideration should therefore be given to CC stabilization with two pins during LCL to prevent this rotatory subluxation.
Background
The European Academy of Paediatric Dentistry (EAPD) proposes this best clinical practice guidance to help practitioners decide when and how to prescribe dental radiographs in children and ...adolescents.
Methods
Four expert working groups conducted each a systematic review of the literature. The main subjects were radiation protection, intraoral dental radiography (bitewing and periapical radiographs), panoramic radiography (PR) and cone-beam computed tomography (CBCT). In addition, three workshops were held during the corresponding EAPD Interim Seminar in Chania (Crete, Greece) in 2019. On the basis of the identified evidence, all invited experts presented their findings and during the workshops aspects of clinical relevance were discussed.
Results
Several clinical-based recommendations and statements were agreed upon.
Conclusion
There is no or low-grade evidence about the efficacy of dental radiographic examinations in young populations. The given recommendations and rationales should be understood as best clinical practice guidance. It is essential to respect the radiological principles of an individualized and patient-specific justification. When a dental radiograph is required, its application needs to be optimized, aiming at limiting the patient’s exposure to ionising radiation according to the ALADAIP principle (
A
s
L
ow
A
s
D
iagnostically
A
chievable being
I
ndication-oriented and
P
atient-specific).
•We organized two challenges for landmark detection, pathology classification and teeth segmentation in dental x-ray image analysis.•Datasets include 400 cephalometric images and 120 bitewing images ...with a referenced standard generated by medical experts.•The datasets and the evaluation software will be made available to the research community, further encouraging future developments in this field.
Display omitted
Dental radiography plays an important role in clinical diagnosis, treatment and surgery. In recent years, efforts have been made on developing computerized dental X-ray image analysis systems for clinical usages. A novel framework for objective evaluation of automatic dental radiography analysis algorithms has been established under the auspices of the IEEE International Symposium on Biomedical Imaging 2015 Bitewing Radiography Caries Detection Challenge and Cephalometric X-ray Image Analysis Challenge. In this article, we present the datasets, methods and results of the challenge and lay down the principles for future uses of this benchmark. The main contributions of the challenge include the creation of the dental anatomy data repository of bitewing radiographs, the creation of the anatomical abnormality classification data repository of cephalometric radiographs, and the definition of objective quantitative evaluation for comparison and ranking of the algorithms. With this benchmark, seven automatic methods for analysing cephalometric X-ray image and two automatic methods for detecting bitewing radiography caries have been compared, and detailed quantitative evaluation results are presented in this paper. Based on the quantitative evaluation results, we believe automatic dental radiography analysis is still a challenging and unsolved problem. The datasets and the evaluation software will be made available to the research community, further encouraging future developments in this field. (http://www-o.ntust.edu.tw/~cweiwang/ISBI2015/)
Background
The detection and diagnosis of caries at the earliest opportunity is fundamental to the preservation of tooth tissue and maintenance of oral health. Radiographs have traditionally been ...used to supplement the conventional visual‐tactile clinical examination. Accurate, timely detection and diagnosis of early signs of disease could afford patients the opportunity of less invasive treatment with less destruction of tooth tissue, reduce the need for treatment with aerosol‐generating procedures, and potentially result in a reduced cost of care to the patient and to healthcare services.
Objectives
To determine the diagnostic accuracy of different dental imaging methods to inform the detection and diagnosis of non‐cavitated enamel only coronal dental caries.
Search methods
Cochrane Oral Health's Information Specialist undertook a search of the following databases: MEDLINE Ovid (1946 to 31 December 2018); Embase Ovid (1980 to 31 December 2018); US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov, to 31 December 2018); and the World Health Organization International Clinical Trials Registry Platform (to 31 December 2018). We studied reference lists as well as published systematic review articles.
Selection criteria
We included diagnostic accuracy study designs that compared a dental imaging method with a reference standard (histology, excavation, enhanced visual examination), studies that evaluated the diagnostic accuracy of single index tests, and studies that directly compared two or more index tests. Studies reporting at both the patient or tooth surface level were included. In vitro and in vivo studies were eligible for inclusion. Studies that explicitly recruited participants with more advanced lesions that were obviously into dentine or frankly cavitated were excluded. We also excluded studies that artificially created carious lesions and those that used an index test during the excavation of dental caries to ascertain the optimum depth of excavation.
Data collection and analysis
Two review authors extracted data independently and in duplicate using a standardised data extraction form and quality assessment based on QUADAS‐2 specific to the clinical context. Estimates of diagnostic accuracy were determined using the bivariate hierarchical method to produce summary points of sensitivity and specificity with 95% confidence regions. Comparative accuracy of different radiograph methods was conducted based on indirect and direct comparisons between methods. Potential sources of heterogeneity were pre‐specified and explored visually and more formally through meta‐regression.
Main results
We included 104 datasets from 77 studies reporting a total of 15,518 tooth sites or surfaces. The most frequently reported imaging methods were analogue radiographs (55 datasets from 51 studies) and digital radiographs (42 datasets from 40 studies) followed by cone beam computed tomography (CBCT) (7 datasets from 7 studies). Only 17 studies were of an in vivo study design, carried out in a clinical setting. No studies were considered to be at low risk of bias across all four domains but 16 studies were judged to have low concern for applicability across all domains. The patient selection domain had the largest number of studies judged to be at high risk of bias (43 studies); the index test, reference standard, and flow and timing domains were judged to be at high risk of bias in 30, 12, and 7 studies respectively.
Studies were synthesised using a hierarchical bivariate method for meta‐analysis. There was substantial variability in the results of the individual studies, with sensitivities that ranged from 0 to 0.96 and specificities from 0 to 1.00. For all imaging methods the estimated summary sensitivity and specificity point was 0.47 (95% confidence interval (CI) 0.40 to 0.53) and 0.88 (95% CI 0.84 to 0.92), respectively. In a cohort of 1000 tooth surfaces with a prevalence of enamel caries of 63%, this would result in 337 tooth surfaces being classified as disease free when enamel caries was truly present (false negatives), and 43 tooth surfaces being classified as diseased in the absence of enamel caries (false positives). Meta‐regression indicated that measures of accuracy differed according to the imaging method (Chi2(4) = 32.44, P < 0.001), with the highest sensitivity observed for CBCT, and the highest specificity observed for analogue radiographs. None of the specified potential sources of heterogeneity were able to explain the variability in results. No studies included restored teeth in their sample or reported the inclusion of sealants.
We rated the certainty of the evidence as low for sensitivity and specificity and downgraded two levels in total for risk of bias due to limitations in the design and conduct of the included studies, indirectness arising from the in vitro studies, and the observed inconsistency of the results.
Authors' conclusions
The design and conduct of studies to determine the diagnostic accuracy of methods to detect and diagnose caries in situ are particularly challenging. Low‐certainty evidence suggests that imaging for the detection or diagnosis of early caries may have poor sensitivity but acceptable specificity, resulting in a relatively high number of false‐negative results with the potential for early disease to progress. If left untreated, the opportunity to provide professional or self‐care practices to arrest or reverse early caries lesions will be missed. The specificity of lesion detection is however relatively high, and one could argue that initiation of non‐invasive management (such as the use of topical fluoride), is probably of low risk.
CBCT showed superior sensitivity to analogue or digital radiographs but has very limited applicability to the general dental practitioner. However, given the high‐radiation dose, and potential for caries‐like artefacts from existing restorations, its use cannot be justified in routine caries detection. Nonetheless, if early incidental carious lesions are detected in CBCT scans taken for other purposes, these should be reported. CBCT has the potential to be used as a reference standard in diagnostic studies of this type.
Despite the robust methodology applied in this comprehensive review, the results should be interpreted with some caution due to shortcomings in the design and execution of many of the included studies. Future research should evaluate the comparative accuracy of different methods, be undertaken in a clinical setting, and focus on minimising bias arising from the use of imperfect reference standards in clinical studies.
PDF
