In this paper we propose a method which uses multiple video images to establish the pose of a CT volume with respect to video camera coordinates for use in image guided surgery. The majority of neurosurgical procedures require the neurosurgeon to relate the pre-operative MR/CT data to the intra-operative scene. Registration of 2D video images to the pre-operative 3D image enables a perspective projection of the pre-operative data to be overlaid onto the video image. Our registration method is based on image intensity and uses a simple iterative optimization scheme to maximize the mutual information between a video image and a rendering from the pre-operative data. Video images are obtained from a stereo operating microscope, with a field of view of approximately 110 X 80 mm. We have extended an existing information theoretical framework for 2D-3D registration, so that multiple video images can be registered simultaneously to the pre-operative data. Experiments were performed on video and CT images of a skull phantom. We took three video images, and our algorithm registered these individually to the 3D image. The mean projection error varied between 4.33 and 9.81 millimeters (mm), and the mean 3D error varied between 4.47 and 11.92 mm. Using our novel techniques we then registered five video views simultaneously to the 3D model. This produced an accurate and robust registration with a mean projection error of 0.68 mm and a mean 3D error of 1.05 mm.
BackgroundEpidemiological evidence has shown that pediatric food allergy is more prevalent in regions further from the equator, suggesting that vitamin D insufficiency may play a role in this disease.ObjectiveTo investigate the role of vitamin D status in infantile food allergy.MethodsA population sample of 5276 one-year-old infants underwent skin prick testing to peanut, egg, sesame, and cow's milk or shrimp. All those with a detectable wheal and a random sample of participants with negative skin prick test results attended a hospital-based food challenge clinic. Blood samples were available for 577 infants (344 with challenge-proven food allergy, 74 sensitized but tolerant to food challenge, 159 negative on skin prick test and food challenge). Serum 25-hydroxyvitamin D levels were measured by using liquid chromatography tandem mass spectrometry. Associations between serum 25-hydroxyvitamin D and food allergy were examined by using multiple logistic regression, adjusting for potential risk and confounding factors.ResultsInfants of Australian-born parents, but not of parents born overseas, with vitamin D insufficiency (≤50 nmol/L) were more likely to be peanut (adjusted odds ratio [aOR], 11.51; 95% CI, 2.01-65.79; P = .006) and/or egg (aOR, 3.79; 95% CI, 1.19-12.08; P = .025) allergic than were those with adequate vitamin D levels independent of eczema status. Among those with Australian-born parents, infants with vitamin D insufficiency were more likely to have multiple food allergies (≥2) rather than a single food allergy (aOR, 10.48; 95% CI, 1.60-68.61 vs aOR, 1.82; 95% CI, 0.38-8.77, respectively).ConclusionsThese results provide the first direct evidence that vitamin D sufficiency may be an important protective factor for food allergy in the first year of life. Epidemiological evidence has shown that pediatric food allergy is more prevalent in regions further from the equator, suggesting that vitamin D insufficiency may play a role in this disease. To investigate the role of vitamin D status in infantile food allergy. A population sample of 5276 one-year-old infants underwent skin prick testing to peanut, egg, sesame, and cow's milk or shrimp. All those with a detectable wheal and a random sample of participants with negative skin prick test results attended a hospital-based food challenge clinic. Blood samples were available for 577 infants (344 with challenge-proven food allergy, 74 sensitized but tolerant to food challenge, 159 negative on skin prick test and food challenge). Serum 25-hydroxyvitamin D levels were measured by using liquid chromatography tandem mass spectrometry. Associations between serum 25-hydroxyvitamin D and food allergy were examined by using multiple logistic regression, adjusting for potential risk and confounding factors. Infants of Australian-born parents, but not of parents born overseas, with vitamin D insufficiency (≤50 nmol/L) were more likely to be peanut (adjusted odds ratio [aOR], 11.51; 95% CI, 2.01-65.79; P = .006) and/or egg (aOR, 3.79; 95% CI, 1.19-12.08; P = .025) allergic than were those with adequate vitamin D levels independent of eczema status. Among those with Australian-born parents, infants with vitamin D insufficiency were more likely to have multiple food allergies (≥2) rather than a single food allergy (aOR, 10.48; 95% CI, 1.60-68.61 vs aOR, 1.82; 95% CI, 0.38-8.77, respectively). These results provide the first direct evidence that vitamin D sufficiency may be an important protective factor for food allergy in the first year of life.
Background: There are frequent concerns about early immunizations among the parents of children at heightened risk for atopy. The study assessed the effect of vaccine immunization before the first birthday on eczema severity and allergic sensitization in the second year of life. Methods: A total of 2184 infants, aged 1–2 years, with established atopic dermatitis and a family history of allergy, from 97 study centres in 10 European countries, South Africa and Australia were included. Exposure to vaccines (diphtheria, tetanus, pertussis, polio, Haemophilus influenzae Type B, hepatitis B, mumps, measles, rubella, varicella, BCG, meningococci and pneumococci) and immunization dates were recorded from immunization cards. Immunoglobulin E (IgE) was determined by RAST and eczema severity was assessed by scoring atopic dermatitis (SCORAD). Results: Immunization against any target was not associated with an increased risk of allergic sensitization to food or inhalant allergens. Varicella immunization (only 0.7% immunized) was inversely associated with total IgE > 30 kU/l (OR 0.27; 95% CI 0.08–0.87) and eczema severity (OR 0.34; 95% CI 0.12–0.93). Pertussis immunization (only 1.7% nonimmunized) was inversely associated with eczema severity (OR 0.30; 95% CI 0.10–0.89). Cumulative received vaccine doses were inversely associated with eczema severity ( P = 0.0107). The immunization coverage of infants before and after the onset of atopic dermatitis was similar. Conclusion: In children at heightened risk for atopy, common childhood immunization in the first year is not associated with an increased risk of more severe eczema or allergic sensitization. Parents of atopic children should be encouraged to fully immunize their children.
Identification of white matter hyperintensities (WMHs) and volume quantification is relevant to dementia diagnosis and for exclusion and efficacy in clinical trials. In AD trials, exclusion of subjects with severe vascular pathology is typically achieved by screening out subjects with a Fazekas score of 3 as obtained from visual read. Robust automated tools are needed to replace visual reads with quantitative methods. We propose a flexible, multi-modal, computationally efficient extension of the Lesion Segmentation Tool (LST) [Schmidt;NeuroImage;2012] (integrated into the Assessa® medical device [Gray;AAIC;2015]). The LST performs a multi-modal WMH segmentation (MRI T1/FLAIR) as the outliers from a preceding segmentation of three tissue classes (CSF, GM, WM). We propose to extend this concept by integrating two additional models describing WMH and non-WMH tissue. The final segmentation is obtained by iteratively updating all five models (CSF, GM, WM, WMH, non-WMH) simultaneously. All models are initialised with spatial priors estimated from a training dataset. Spatial priors are iteratively updated accounting for registration errors. An estimate of the bias field is iteratively updated, mitigating the risk of erroneous sequential bias correction. We present a comparison to manual segmentation and a visual read based on Fazekas scoring. For a dataset of 38 subjects with a diagnosis of AD, a mean DICE overlap of 0.55 is observed between automated and manual segmentations. Correlation between manual and automatic WMH volume estimate is R2=0.94 (Fig1a). Fig1b shows for the 38 subjects the volumes from (a) manual segmentation, (b) the LST and (c) the proposed method over their Fazekas score. Identifying a cut point in a leave-one-out fashion and applying it to the remaining subject, gives concordance with an exclusion criteria of Fazekas=3 of 82% with the LST and 92% with both the proposed method and manual volumetry. Average cut points on WMH/ICV are 1.51%, 2.16%, 2.23% for LST, the proposed method and manual volumetry respectively. The presented method provides an accurate tool to automatically quantify WMH's. It provides an improved robustness to discriminate subjects with significant WMH (Fazekas=3) hinting at its potential to serve as an automated eligibility measure for clinical trials. a (left): correlation, b (right) volume over Fazekas scores
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