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We report the case of an infant in whom congenital syphilis was diagnosed at the age of 5 weeks. The case is remarkable because of (a) the negative venereal disease laboratory test from the cord blood, (b) the incidental diagnosis of the... more
We report the case of an infant in whom congenital syphilis was diagnosed at the age of 5 weeks. The case is remarkable because of (a) the negative venereal disease laboratory test from the cord blood, (b) the incidental diagnosis of the disease in the fifth week of life, (c) pneumonia alba being one of the symptoms, (d) the occurrence of a mild Jarisch-Herxheimer reaction after initiation of penicillin therapy and (e) the successful treatment of infection related anaemia with recombinant human erythropoietin.
This Guideline refers to infants, children and adolescents aged 0-18 years. The areas covered include: indications for diagnostic and therapeutic esophagogastroduodenoscopy and ileo-colonoscopy; endoscopy for foreign body ingestion;... more
This Guideline refers to infants, children and adolescents aged 0-18 years. The areas covered include: indications for diagnostic and therapeutic esophagogastroduodenoscopy and ileo-colonoscopy; endoscopy for foreign body ingestion; corrosive ingestion and stricture/stenosis endoscopic management; upper and lower gastrointestinal bleeding; endoscopic retrograde cholangio-pancreatography and endoscopic ultrasonography. Percutaneous endoscopic gastrostomy and endoscopy specific to inflammatory bowel disease (IBD) has been dealt with in other Guidelines [1-3] and are therefore not mentioned in this Guideline. Training and ongoing skill maintenance are to be dealt with in an imminent sister publication to this.
doi: 10.3389/fnhum.2014.00502 On the generalizability of resting-state fMRI machine learning classifiers
ABSTRACT We evaluate different cross-validation (CV) protocols for an automated classification of colonic polyps. For this purpose we select six previously developed methods which achieved promising results already in the past. We then... more
ABSTRACT We evaluate different cross-validation (CV) protocols for an automated classification of colonic polyps. For this purpose we select six previously developed methods which achieved promising results already in the past. We then evaluate the methods using the cross-validation protocols leave-one-image-out (LOO-CV), leave-one-parent-image-out (LOPIO-CV), leave-one-lesion-out (LOLO-CV), and leave-one-patient-out (LOPO-CV). We show that, in general, the more restrictive cross-validation protocols lead to high results drops. While in case of LOO-CV the accuracies are rather high across all methods evaluated, the picture changes the more strictness a cross-validation mode imposes on the set of training images.
ABSTRACT Local Binary Patterns (LBP) is a widely used approach for medical image analysis. Limitations of the LBP operator are its sensitivity to noise and its boundedness to first derivative information. These limitations are usually... more
ABSTRACT Local Binary Patterns (LBP) is a widely used approach for medical image analysis. Limitations of the LBP operator are its sensitivity to noise and its boundedness to first derivative information. These limitations are usually balanced by extensions of the classical LBP operator (e.g. the Local Ternary Pattern operator (LTP) or the Extended LBP (ELBP) operator). In this paper we present a generic framework that is able to overcome this limitations by frequency filtering the images as pre-processing stage to the classical LBP. The advantage of this approach is its easier adaption and optimization to different application scenarios and data sets as compared to other LBP variants. Experiments are carried out employing two endoscopic data sets, the first from the duodenum used for diagnosis of celiac disease, the second from the colon used for polyp malignity assessment. It turned out that high pass filtering combined with LBP outperforms classical LBP and most of its extensions, whereas low pass filtering effects the results only to a small extent.
ABSTRACT Interlaced scanning is a technique that has been widely in use to double the perceived frame rate without increasing the used bandwidth. Interlaced scanning is still in use by endoscopic video hardware today. Towards the... more
ABSTRACT Interlaced scanning is a technique that has been widely in use to double the perceived frame rate without increasing the used bandwidth. Interlaced scanning is still in use by endoscopic video hardware today. Towards the development of an automated decision support system we focus on the evaluation of the impact of de-interlacing techniques on the accuracy of automated classification of endoscopic video data with indication for celiac disease. In a large experimental setup a variety of de-interlacing methods are evaluated using a set of feature extraction methods from the fields of pattern recognition and medical image analysis.
ABSTRACT In this paper, we present variants of the Dual-Tree Complex Wavelet Transform (DT-CWT) in order to automatically classify endoscopic images with respect to the Marsh classification. The feature vectors either consist of the means... more
ABSTRACT In this paper, we present variants of the Dual-Tree Complex Wavelet Transform (DT-CWT) in order to automatically classify endoscopic images with respect to the Marsh classification. The feature vectors either consist of the means and standard deviations of the subbands from a DT-CWT variant or of the Weibull parameter of these subbands. To reduce the effects of different distances and perspectives toward the mucosa, we enhanced the scale invariance by applying the discrete Fourier transform or the discrete cosine transform across the scale dimension of the feature vector.
In this paper, scale invariant features are extracted from different variants of the Dual-Tree Complex Wavelet Transform (DT-CWT) in order to classify high-magnification colon endoscopy imagery with respect to the pit pattern scheme. To... more
In this paper, scale invariant features are extracted from different variants of the Dual-Tree Complex Wavelet Transform (DT-CWT) in order to classify high-magnification colon endoscopy imagery with respect to the pit pattern scheme. To enhance the scale invariance, the Discrete Cosine Transform is applied to the feature vectors, that are achieved from a DT-CWT variant. The feature vectors either consist
In this paper we present a viewpoint invariant method using fractal features for the automatic classification of celiac disease. First the endoscopic images of the duodenum are pre-filtered using the MR8 filter bank. Subsequently we... more
In this paper we present a viewpoint invariant method using fractal features for the automatic classification of celiac disease. First the endoscopic images of the duodenum are pre-filtered using the MR8 filter bank. Subsequently we compute the local fractal dimension of each pixel of the filter responses. After finding representative combinations of the local fractal dimensions for images with or without celiac disease, we generate frequency histograms that count how often each representative combinations occur as nearest neighbor for each image (as nearest neighbor to the local fractal dimensions of the filter responses for each pixel position of the images). We use this histograms for the classification of the images. We will see that the result of the proposed method outperforms the approach, our method is based on, as well as other methods for the classification of medical imagery.
Research Interests:
SPECIFIC AUTHOR CONTRIBUTIONS: Andreas Vécsei, MD, and Ulrike Graf wrote the manuscript. All authors contributed to study design, data collection and analysis, and approved the final draft for submission. The corresponding author declares... more
SPECIFIC AUTHOR CONTRIBUTIONS: Andreas Vécsei, MD, and Ulrike Graf wrote the manuscript. All authors contributed to study design, data collection and analysis, and approved the final draft for submission. The corresponding author declares that the manuscript is submitted on behalf of all authors. The best mode of follow-up in celiac disease has not yet been established. The intention of this study was to clarify which noninvasive follow-up investigation - serological tests or intestinal permeability test (IPT) - correlates best with histology and whether the interval between diagnosis and follow-up affects the accuracy of these tests. Data from adult patients with celiac disease (diagnosed between December 1989 and July 2006) followed up with biopsy, IPT, and serological tests [IgG anti-gliadin antibodies (AGA-IgG), AGA-IgA, and endomysial antibodies (EMA)] were retrieved from a computerized database. Results of noninvasive tests were compared with the persistence of villous atrophy on biopsy. Patients were divided into groups A, which comprised patients followed up within 2 years after diagnosis, and B, comprising patients followed up later than 2 years. Forty-seven patients were evaluable. The lactulose/mannitol (L/M) ratio had a sensitivity of 85 % and a specificity of 46.2 % for mucosal atrophy, whereas saccharose excretion showed a sensitivity of 60 % and a specificity of 52.6 %. The sensitivities of AGA-IgA and AGA-IgG were 15 % and 20 %, respectively, while specificity was 100 % for both. Validity of AGA was limited due to low number of positive results. EMA assay was 50 % sensitive and 77.8 % specific. In group A (n = 23) L/M ratio performed best in terms of sensitivity (88.9 %), whereas EMA achieved a higher specificity (71.4 %). In group B, the sensitivity of the L/M ratio decreased to 85.7 %, while the specificity of EMA increased to 91.7 %. In this study, none of the noninvasive tests was an accurate substitute for follow-up biopsy in detecting severe mucosal damage.
Distortion correction is applied to endoscopic duodenal imagery to improve automated classification of celiac disease affected mucosa patches. In a set of six edge- and shape-related feature extraction techniques, only a single one is... more
Distortion correction is applied to endoscopic duodenal imagery to improve automated classification of celiac disease affected mucosa patches. In a set of six edge- and shape-related feature extraction techniques, only a single one is able to consistently benefit from distortion correction, while for others, even a decrease of classification accuracy is observed. Different types of distortion correction do not lead to significantly different behaviour in the observed application scenario.

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