22 research outputs found
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Utilizing anatomical information for signal detection in functional magnetic resonance imaging
We are considering the statistical analysis of functional magnetic resonance imaging (fMRI) data. As demonstrated in previous work, grouping voxels into regions (of interest) and carrying out a multiple test for signal detection on the basis of these regions typically leads to a higher sensitivity when compared with voxel-wise multiple testing approaches. In the case of a multi-subject study, we propose to define the regions for each subject separately based on their individual brain anatomy, represented, e.g., by so-called Aparc labels. The aggregation of the subject-specific evidence for the presence of signals in the different regions is then performed by means of a combination function for p-values. We apply the proposed methodology to real fMRI data and demonstrate that our approach can perform comparably to a two-stage approach for which two independent experiments are needed, one for defining the regions and one for actual signal detection
Gastrointestinal bleeding 30 years after a complicated cholecystectomy
Gastrointestinal bleeding from small-bowel varices is a rare and difficult to treat complication of portal hypertension. We describe the case of a 79-year-old female patient with recurrent severe hemorrhage from small-bowel varices 30 years after a complicated cholecystectomy. When double balloon enteroscopy was unsuccessful to reach the site of bleeding, a rendezvous approach was favored with intraoperative endoscopy. Active bleeding from varices within a biliodigestive anastomosis was found and controlled by endoscopic injection of cyanoacrylate. Intraoperative endoscopy should be considered in the case of life-threatening gastrointestinal hemorrhage that is not accessible by conventional endoscopy
Supplemental material for Gastrointestinal endoscopy under sedation is associated with pneumonia in older inpatients—results of a retrospective case-control study
<p>Supplemental Material for Gastrointestinal endoscopy under sedation is associated
with pneumonia in older inpatients—results of a retrospective
case-control study by Christopher M Kollmann, Wolff Schmiegel and Thorsten
Brechmann in United European Gastroenterology Journal</p
Utilizing anatomical information for signal detection in functional magnetic resonance imaging
We are considering the statistical analysis of functional magnetic resonance imaging (fMRI) data. As demonstrated in previous work, grouping voxels into regions (of interest) and carrying out a multiple test for signal detection on the basis of these regions typically leads to a higher sensitivity when compared with voxel-wise multiple testing approaches. In the case of a multi-subject study, we propose to define the regions for each subject separately based on their individual brain anatomy, represented, e.g., by so-called Aparc labels. The aggregation of the subject-specific evidence for the presence of signals in the different regions is then performed by means of a combination function for p-values. We apply the proposed methodology to real fMRI data and demonstrate that our approach can perform comparably to a two-stage approach for which two independent experiments are needed, one for defining the regions and one for actual signal detection