Fluorodeoxyglucose (FDG) positron emission tomography (PET) measures the decline in the regional cerebral metabolic rate for glucose, offering a reliable metabolic biomarker even on presymptomatic Alzheimer’s disease (AD) patients. PET scans provide functional information that is unique and unavailable using other types of imaging. However, the computational efficacy of FDG-PET data alone, for the classification of various Alzheimers Diagnostic categories, has not been well studied. This motivates us to correctly discriminate various AD Diagnostic categories using FDG-PET data. Deep learning has improved state-of-the-art classification accuracies in the areas of speech, signal, image, video, text mining and recognition. We propose novel methods that involve probabilistic principal component analysis on max-pooled data and mean-pooled data for dimensionality reduction, and multilayer feed forward neural network which performs binary classification. Our experimental dataset consists of baseline data of subjects including 186 cognitively unimpaired (CU) subjects, 336 mild cognitive impairment (MCI) subjects with 158 Late MCI and 178 Early MCI, and 146 AD patients from Alzheimer’s Disease Neuroimaging Initiative (ADNI) dataset. We measured F1-measure, precision, recall, negative and positive predictive values with a 10-fold cross validation scheme. Our results indicate that our designed classifiers achieve competitive results while max pooling achieves better classification performance compared to mean-pooled features. Our deep model based research may advance FDG-PET analysis by demonstrating their potential as an effective imaging biomarker of AD.
Children born preterm are at risk for a wide range of neurocognitive and neurobehavioral disorders. Some of these may stem from early brain abnormalities at the neonatal age. Hence, a precise characterization of neonatal neuroanatomy may help inform treatment strategies. In particular, the ventricles are often enlarged in neurocognitive disorders, due to atrophy of surrounding tissues. Here we present a new pipeline for the detection of morphological and relative pose differences in the ventricles of premature neonates compared to controls. To this end, we use a new hyperbolic Ricci flow based mapping of the ventricular surfaces of each subjects to the Poincaré disk. Resulting surfaces are then registered to a template, and a between group comparison is performed using multivariate tensor-based morphometry. We also statistically compare the relative pose of the ventricles within the brain between the two groups, by performing a Procrustes alignment between each subject's ventricles and an average shape. For both types of analyses, differences were found in the left ventricles between the two groups.
Wireless video capsule endoscope (VCE) provides a noninvasive method to examine the entire gastrointestinal
(GI) tract, especially small intestine, where other endoscopic instruments can barely reach. VCE is able to
continuously provide clear pictures in short fixed intervals, and as such researchers have attempted to use image
processing methods to track the video capsule in order to locate the abnormalities inside the GI tract. To
correctly estimate the speed of the motion of the endoscope capsule, the radius of the intestinal track must be
known a priori. Physiological factors such as intestinal contraction, however, dynamically change the radius of
the small intestine, which could bring large errors in speed estimation. In this paper, we are aiming to estimate
the radius of the contracted intestinal track. First a geometric model is presented for estimating the radius of
small intestine based on the black hole on endoscopic images. To validate our proposed model, a 3-dimentional
virtual testbed that emulates the intestinal contraction is then introduced in details. After measuring the size
of the black holes on the test images, we used our model to esimate the radius of the contracted intestinal track.
Comparision between analytical results and the emulation model parameters has verified that our proposed
method could preciously estimate the radius of the contracted small intestine based on endoscopic images.
This paper presents a robust method to search for the correct SIFT keypoint matches with adaptive distance ratio threshold. Firstly, the reference image is analyzed by extracting some characteristics of its SIFT keypoints, such as their distance to the object boundary and the number of their neighborhood keypoints. The matching credit of each keypoint is evaluated based on its characteristics. Secondly, an adaptive distance ratio threshold for the keypoint is determined based on its matching credit to identify the correctness of its best match in the source image. The adaptive threshold loosens the matching conditions for keypoints of high matching credits and tightens the conditions for those of low matching credits. Our approach improves the scheme of SIFT keypoint matching by applying adaptive distance ratio threshold rather than global threshold that ignores different matching credits of various keypoints. The experiment results show that our algorithm outperforms the standard SIFT matching method in some complicated cases of object recognition, in which it discards more false matches as well as preserves more correct matches.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.