Mapping the timeliness of routine childhood vaccination in The Gambia: A spatial modelling study.

INTRODUCTION: Timeliness of routine vaccination shapes childhood infection risk and thus is an important public health metric. Estimates of indicators of the timeliness of vaccination are usually produced at the national or regional level, which may conceal epidemiologically relevant local heterogeneities and makeitdifficultto identify pockets of vulnerabilities that could benefit from targeted interventions. Here, we demonstrate the utility of geospatial modelling techniques in generating high-resolution maps of the prevalence of delayed childhood vaccination in The Gambia. To guide local immunisation policy and prioritize key interventions, we also identified the districts with a combination of high estimated prevalence and a significant population of affected infants. METHODS: We used the birth dose of the hepatitis-B vaccine (HepB0), third-dose of the pentavalent vaccine (PENTA3), and the first dose of measles-containing vaccine (MCV1) as examples to map delayed vaccination nationally at a resolution of 1 × 1-km2 pixel. We utilized cluster-level childhood vaccination data from The Gambia 2019-20 Demographic and Health Survey. We adopted a fully Bayesian geostatistical model incorporating publicly available geospatial covariates to aid predictive accuracy. The model was implemented using the integrated nested Laplace approximation-stochastic partial differential equation (INLA-SPDE) approach. RESULTS: We found significant subnational heterogeneity in delayed HepB0, PENTA3 and MCV1 vaccinations. Specificdistricts in the central and eastern regions of The Gambia consistentlyexhibited the highest prevalence of delayed vaccination, while the coastal districts showed alower prevalence forallthree vaccines. We also found that districts in the eastern, central, as well as in coastal parts of The Gambia had a combination of high estimated prevalence of delayed HepB0, PENTA3 and MCV1 and a significant population of affected infants. CONCLUSIONS: Our approach provides decision-makers with a valuable tool to better understand local patterns of untimely childhood vaccination and identify districts where strengthening vaccine delivery systems could have the greatest impact

Idiopathic root resorption of the entire permanent dentition: Systematic review and report of a case

PubMed ID: 18721356A rare case of idiopathic root resorption affecting the entire dentition was described. Root resorptions of all of the maxillary and mandibular teeth were coincidentally diagnosed on patient's radiographic examination. The patient's medical and dental findings were non-contributory, other than the increased mobility of upper incisors. No significant familial findings could be identified. Detailed radiographic examination revealed resorption affecting the apical part of the roots, resulting in vertical shortening of the teeth. The character of the resorption was as if a tapering occurred throughout the lateral root surfaces. Involved teeth were endodontically treated and the patient was subsequently followed-up for 18 months. Following endodontic therapy, all periapical lesions demonstrated clinical and radiographic evidence of healing. Endodontic therapy resulted in a high degree of success to stop resorption process and maintain the dentition. © 2008 The Authors

The effect of delayed scanning of storage phosphor plates on occlusal caries detection

PubMed ID: 22282506Objective: The aim of this study was to determine (1) the effect of various scan delays on pixel intensity measurements and (2) the diagnostic accuracy of occlusal caries detection. Methods: 72 non-cavitated extracted human permanent molar teeth with sound and carious occlusal surfaces were radiographed using the DIGORA ® storage phosphor plates (SPPs) (Soredex Corporation, Helsinki, Finland). Plates were scanned immediately and 10 min, 30 min, 60 min and 120 min after exposure. Three different plates were used for each scan delay. An aluminium (Al) wedge was used to evaluate the change in mean grey values (MGVs) for scan delays. Diagnostic accuracy for occlusal caries detection was performed by scoring all the digital images. The true presence of caries was determined by stereomicroscopy. Comparison of MGVs of the Al wedge for immediate and delayed scans was made using repeated measures analysis of variance (ANOVA) and Tukey-Kramer tests. The accuracy was expressed as the area under the receiver operating characteristics curves (A z). A zs were compared using two-way ANOVA and t-tests. Kappa was used to measure inter and intraobserver agreement. Results: The mean A zs of immediately scanned plates were higher than the A zs of plates scanned with four different delays (p < 0.05). The A z of immediately scanned images was significantly higher than the A zs of images with 60 min and 120 min scan delays (p < 0.05) but not for 10min and 30min delays (p > 0.05). MGVs of immediately scanned plates were significantly higher than the plates scanned with four different delays (p < 0.05). Agreement decreased with increasing scan delays. Conclusion: Scanning of DIGORA SPPs should not be delayed beyond 30min for accurate occlusal caries diagnosis. © 2012 The British Institute of Radiology

Perceptibility curve test for digital radiographs before and after application of various image processing algorithms

WOS: 000251682300008PubMed ID: 18033946Objectives: The aim of the present study was to compare digital radiographs before and after the application of various digital image enhancement methods by means of a perceptibility curve (PC) test. Methods: Radiographs of an aluminium test object containing holes with sizes ranging from 0.5 mm to 1.5 mm were exposed at nine time settings, ranging from 0.05 s to 3.2 s using Digora(R) (Soredex, Helsinki, Finland) storage phosphor system. Original digital images were then enhanced and displayed in colour-coded, contrast- and brightness-enhanced, histogram-equalized and negative modes. Thus, five series of images were created. Eight observers independently evaluated all of the images in the same random order and under the same viewing conditions. The object detail with the lowest perceptible contrast was recorded for each observer and each image type. Modified PCs were plotted according to the mean observer data. Repeated-measures ANOVA was used to compare the PCs and the perceptible number of details in original and enhanced images for each exposure (P = 0.05). The Bonferroni/Dunn test was used to identify statistical differences among the groups. Results: Histogram equalization showed the maximum number of perceptible details in both the lowest optimal exposure time and the widest exposure range (P 0.05). Conclusion: Histogram-equalization enhancement of Digora(R) images demonstrated subjectively superior image quality, followed by contrast and brightness enhancement

Imaging of root canal fillings: a comparison of subjective image quality between limited cone-beam CT, storage phosphor and film radiography

Aim To compare the subjective quality of limited cone-beam computed tomography (LCBCT), storage phosphor plate (SPP) and F-speed film images for the evaluation of length and homogeneity of root fillings. Methodology Root canals of 17 extracted permanent mandibular incisor teeth were filled. With the teeth placed in their jaws, images were obtained with Accu-I-Tomo LCBCT, Digora® Optime image plate system and F-speed film using exposure parameters yielding ‘clinically’ acceptable density and contrast. Three radiologists and three endodontists independently rated the quality of all images in respect to homogeneity and the length of root fillings using a 3-graded scale. Evaluations were undertaken in two sessions. In the first, the coronal LCBCT images were not included. In the second, both coronal and sagittal LCBCT images were rated along with F-speed film and SPP images. Results were compared using the Friedman test (P < 0.05). Pair-wise comparisons of systems were completed using the Wilxocon signed-ranks test (P < 0.05). Kappa was used to measure interobserver agreement. Results Digora images were rated superior, consecutively followed by F-speed films and LCBCT images, for the evaluation of both homogeneity and length of root fillings in both the evaluation sessions (P < 0.05). Kappa ranged from slight to moderate for the length evaluation of root fillings and from poor to fair for the evaluation of homogeneity of root fillings. Conclusion Image quality of storage phosphor images was subjectively as good as conventional film images and superior to LCBCT images for the evaluation of both homogeneity and length of root fillings in single-rooted teeth

Perception of anatomical structures in digitally filtered and conventional panoramic radiographs: a clinical evaluation

WOS: 000281761200005PubMed ID: 20841460Objectives: The aims of the study were to compare subjective image quality of clinical images obtained with a storage phosphor plate (SPP)-based digital and conventional film-based panoramic system for the visualization of various anatomical structures and to evaluate the effect of various processing algorithms on image interpretation. Methods: Panoramic radiographs were taken in 42 patients both with film and with a SPP system. SPP images were treated with shadow, sharpen, negative, greyscale sigma and greyscale exponential filters. Four observers subjectively evaluated films and unfiltered and filtered SPP images for the visibility of anatomical structures with various radiodensities as well as for overall image quality on a three-point rating scale. The statistical methods used were Kruskal-Wallis, odds ratio analysis and Cohen's kappa. Results: No statistically significant difference was found between film and unfiltered digital images except for low-contrast structures (P > 0.05). Film images were preferred for the visibility of low-contrast structures (P < 0.05). Best overall image quality was obtained with sharpened images (P < 0.05) followed by films and unfiltered digital images. Among all filtered images, sharpened ones received the highest ratings for the visibility of all anatomical structures (P < 0.05). The intra- and interobserver agreement ranged between moderate and substantial and between fair and moderate, respectively. Conclusions: Film and unfiltered SPP-based panoramic images performed equally well in terms of overall quality; however, films were best for the perception of low-contrast structures. The sharpening filter may be recommended for enhancing SPP panoramic images to improve the visual perception of most of the anatomical structures as well as overall quality. Dentomaxillofacial Radiology (2010) 39, 424-430. doi: 10.1259/dmfr/3057037