Wavelet-based Rician noise removal for magnetic resonance imaging

1999 ◽  
Vol 8 (10) ◽  
pp. 1408-1419 ◽  
Author(s):  
R.D. Nowak
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Noise Removal ◽  
Rician Noise ◽  
Resonance Imaging

scholarly journals Local Complexity Estimation Based Filtering Method in Wavelet Domain for Magnetic Resonance Imaging Denoising

Entropy ◽  
2019 ◽  
Vol 21 (4) ◽  
pp. 401 ◽  
Author(s):  
Izlian Y. Orea-Flores ◽  
Francisco J. Gallegos-Funes ◽  
Alfonso Arellano-Reynoso
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Additive White Gaussian Noise ◽  
Noise Removal ◽  
Wavelet Domain ◽  
Resonance Imaging ◽  
Comparative Performance ◽  
Filtering Method ◽  
Local Complexity ◽  
Complexity Estimation

In this paper, we propose the local complexity estimation based filtering method in wavelet domain for MRI (magnetic resonance imaging) denoising. A threshold selection methodology is proposed in which the edge and detail preservation properties for each pixel are determined by the local complexity of the input image. In the proposed filtering method, the current wavelet kernel is compared with a threshold to identify the signal- or noise-dominant pixels in a scale providing a good visual quality avoiding blurred and over smoothened processed images. We present a comparative performance analysis with different wavelets to find the optimal wavelet for MRI denoising. Numerical experiments and visual results in simulated MR images degraded with Rician noise demonstrate that the proposed algorithm consistently outperforms other denoising methods by balancing the tradeoff between noise suppression and fine detail preservation. The proposed algorithm can enhance the contrast between regions allowing the delineation of the regions of interest between different textures or tissues in the processed images. The proposed approach produces a satisfactory result in the case of real MRI denoising by balancing the detail preservation and noise removal, by enhancing the contrast between the regions of the image. Additionally, the proposed algorithm is compared with other approaches in the case of Additive White Gaussian Noise (AWGN) using standard images to demonstrate that the proposed approach does not need to be adapted specifically to Rician or AWGN noise; it is an advantage of the proposed approach in comparison with other methods. Finally, the proposed scheme is simple, efficient and feasible for MRI denoising.

Spatially variable Rician noise in magnetic resonance imaging

2012 ◽  
Vol 16 (2) ◽  
pp. 536-548 ◽  
Author(s):  
Ivan I. Maximov ◽  
Ezequiel Farrher ◽  
Farida Grinberg ◽  
N. Jon Shah
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Rician Noise ◽  
Resonance Imaging

scholarly journals Global Canny algorithm based on Canny edge detector framework in magnetic resonance imaging

2017 ◽  
Vol 13 (4-2) ◽  
pp. 445-451
Author(s):  
Tengku Ahmad Iskandar Tengku Alang ◽  
Tan Tian Swee ◽  
Tan Jia Hou ◽  
Leong Kah Meng ◽  
Sameen Ahmed Malik ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Edge Detection ◽  
Medical Image Analysis ◽  
Magnetic Resonance Images ◽  
Rician Noise ◽  
Resonance Imaging ◽  
Edge Detector ◽  
Canny Edge Detector ◽  
Canny Edge

Magnetic resonance imaging is an important modality in the diagnosis and pathology detection. Edge detection is used for image segmentation and feature extraction as part of the medical image analysis. There is no ideal and universal algorithm which performs perfectly under all conditions. Conventional Canny edge detector is not suitable to be used in Magnetic resonance images that contaminated by Rician noise. In this paper, we propose the use of customized non-local means into the Canny edge detector instead of Gaussian smoothing in the conventional Canny edge detector to effectively remove Rician noise while preserving edges in Magnetic resonance image of an internal organ. The result shows that our method can yield better edge detection than conventional method, with minimal false edge detection. The proposed method undergoes several attempts of parameter adjustment to detect true edges successfully using optimal parameter setting.

Functional information from magnetic resonance imaging

1995 ◽  
Vol 53 ◽  
pp. 84-85
Author(s):  
Alan P. Koretsky ◽  
Afonso Costa e Silva ◽  
Yi-Jen Lin
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Cancer Biology ◽  
Imaging Modality ◽  
Magnetic Resonance Images ◽  
Great Success ◽  
Functional Information ◽  
Resonance Imaging ◽  
High Resolution Mri

Magnetic resonance imaging (MRI) has become established as an important imaging modality for the clinical management of disease. This is primarily due to the great tissue contrast inherent in magnetic resonance images of normal and diseased organs. Due to the wide availability of high field magnets and the ability to generate large and rapidly switched magnetic field gradients there is growing interest in applying high resolution MRI to obtain microscopic information. This symposium on MRI microscopy highlights new developments that are leading to increased resolution. The application of high resolution MRI to significant problems in developmental biology and cancer biology will illustrate the potential of these techniques.In combination with a growing interest in obtaining high resolution MRI there is also a growing interest in obtaining functional information from MRI. The great success of MRI in clinical applications is due to the inherent contrast obtained from different tissues leading to anatomical information.

Functional Magnetic Resonance Imaging Measures of Blood Flow Patterns in the Human Auditory Cortex in Response to Sound

1998 ◽  
Vol 41 (3) ◽  
pp. 538-548 ◽  
Author(s):  
Sean C. Huckins ◽  
Christopher W. Turner ◽  
Karen A. Doherty ◽  
Michael M. Fonte ◽  
Nikolaus M. Szeverenyi
Keyword(s):  
Magnetic Resonance Imaging ◽  
Blood Flow ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Speech Stimuli ◽  
Complex Stimuli ◽  
Scanning Session ◽  
Auditory Research

Functional Magnetic Resonance Imaging (fMRI) holds exciting potential as a research and clinical tool for exploring the human auditory system. This noninvasive technique allows the measurement of discrete changes in cerebral cortical blood flow in response to sensory stimuli, allowing determination of precise neuroanatomical locations of the underlying brain parenchymal activity. Application of fMRI in auditory research, however, has been limited. One problem is that fMRI utilizing echo-planar imaging technology (EPI) generates intense noise that could potentially affect the results of auditory experiments. Also, issues relating to the reliability of fMRI for listeners with normal hearing need to be resolved before this technique can be used to study listeners with hearing loss. This preliminary study examines the feasibility of using fMRI in auditory research by performing a simple set of experiments to test the reliability of scanning parameters that use a high resolution and high signal-to-noise ratio unlike that presently reported in the literature. We used consonant-vowel (CV) speech stimuli to investigate whether or not we could observe reproducible and consistent changes in cortical blood flow in listeners during a single scanning session, across more than one scanning session, and in more than one listener. In addition, we wanted to determine if there were differences between CV speech and nonspeech complex stimuli across listeners. Our study shows reproducibility within and across listeners for CV speech stimuli. Results were reproducible for CV speech stimuli within fMRI scanning sessions for 5 out of 9 listeners and were reproducible for 6 out of 8 listeners across fMRI scanning sessions. Results of nonspeech complex stimuli across listeners showed activity in 4 out of 9 individuals tested.

Sign in / Sign up

Export Citation Format

Share Document