With the advent of biomarkers such as 11C-PIB and the increase in use of PET, automated methods are required for processing and analyzing datasets from research studies and in clinical settings. A common preprocessing step is the calculation of standardized uptake value ratio (SUVR) for inter-subject normalization. This requires segmented grey matter (GM) for VOI refinement. However 11C-PIB upt...

Introduction: Successful water and fat separation in a Dixon technique [1] requires reliable and consistent correction of phase errors that are caused by the magnetic field inhomogeneity. Among different phase correction algorithms that have been published, region growing does not require a priori assumption on the spatial distribution of the field inhomogeneity and has been successful in many ...

GENERALIZED SCALE: THEORY, ALGORITHMS, AND APPLICATIONS IN IMAGE ANALYSIS Anant Madabhushi Supervisor: Jayaram K. Udupa Magnetic Resonance (MR) Imaging (MRI) is a non-invasive method for imaging the human body and has revolutionized medical imaging. MR image processing, particularly segmentation, and analysis are used extensively in medical and clinical research for advancing our understanding ...

Field inhomogeneity and susceptibility variations, coupled with a long readout, can result in image blurring in spiral imaging. Many correction methods based on a priori off-resonance information, such as an acquired field map, have been proposed in the literature. Automatic off-resonance correction methods are alternative approaches that estimate a field map from the image data themselves. In ...

Quantitative MR Imaging and Spectroscopy Group, Research Center for Cellular and Molecular Imaging, Tehran University of Medical Sciences, Tehran, Iran Deriving an accurate attenuation correction map (μ-map) from magnetic resonance (MR) volumes has become an important problem in hybrid PET/MR imaging. Recently, short echo-time (STE) MR imaging technique incorporating fuzzy C-means (FCM) tissue ...

This paper presents the modelling and segmentation with correction of inhomogeneity in magnetic resonance imaging of shoulder. For that purpose a new heuristic is proposed using a morphological method and a pyramidal Gaussian decomposition (Discrete Gabor Transform). After the application of these filters, an automatic segmentation of a bone is possible despite of other semiautomatic methods pr...

Introduction: At high magnetic field strength, B1 inhomogeneity causes undesired effects of non-uniformity in SNR and contrast. For slice selective excitation, 3D RF pulse design proposed in [1,2,3], can be used to mitigate this B1 inhomogeneity effect. These designs are based on playing kz sinc “spokes” of different amplitude at a number of (kx,ky) locations around the k-space origin. The sinc...

A correction method for inhomogeneity of magnetic resonance (MR) images was developed based on renormalization transformation. It is a post-processing algorithm on images. Unlike previous post-processing methods, which need to determine either a filter size or a free adjustable parameter for different applications, this presented method is fully automated. Tests on physical phantom data, patien...