Robust phase sensitive inversion recovery imaging /
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| Format: | Thesis eBook |
| Language: | English |
| Published: |
[College Station, Tex.] :
[Texas A&M University],
[2005]
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| Subjects: | |
| Online Access: | Link to OAK Trust copy |
| Abstract: | Inversion Recovery (IR) is a powerful tool for contrast manipulation in Magnetic Resonance Imaging (MRI). IR can provide strong contrast between tissues with different values of T1 relaxation times. The tissue magnetization stored at an IRimage pixel can take positive as well as negative values. The corresponding polarity information is contained in the phase of the complex image. Due to numerous factors associated with the Magnetic Resonance (MR) scanner and the associated acquisition system, the acquired complex image is modulated by a spatially varying background phase which makes the retrieval of polarity information non-trivial. Many commercial MR scanners perform magnitude-only reconstruction which, due to loss of polarity information, reduces the dynamic contrast range. Phase sensitive IR (PSIR) can provide enhanced image contrast by estimating and removing the background phase and retrieving the correct polarity information. In this thesis, the background phase of complex MR image is modeled using a statistical model based on Markov Random Fields (MRF). Two model optimization methods have been developed. The first method is a computationally effcient algorithm for finding semi-optimal solutions satisfying the proposed model. Using an adaptive model neighborhood, it can reconstruct low SNR images with slow phase variations. The second method presents a region growing approach which can handle images with rapid phase variations. Experimental results using computer simulations and in vivo experiments show that the proposed method is robust and can perform successful reconstruction even in adverse cases of low signal to noise ratios (SNRs) and high phase variations. |
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| Item Description: | "Major Subject: Electrical Engineering" Title from author supplied metadata (automated record created on Nov. , 09:45:50.) Vita. Abstract. Electronic resource. |
| Format: | Mode of access: World Wide Web. System requirements: World Wide Web access and Adobe Acrobat Reader. |
| Bibliography: | Includes bibliographical references. |