Award Date

12-2011

Degree Type

Thesis

Degree Name

Master of Science in Health Physics

Department

Health Physics and Diagnostic Sciences

First Committee Member

Phillip Patton, Chair

Second Committee Member

Phillip Patton

Third Committee Member

Ralf Sudowe

Graduate Faculty Representative

Barbara Luke

Number of Pages

82

Abstract

Diffusion weighted imaging (DWI) is a magnetic resonance imaging (MRI) method that produces in vivo images of biological tissues weighted with the local micro-structural characteristics of water diffusion. Diffusion tensor imaging (DTI), a form of DWI, is useful when a tissue, such as the neural axons of white matter in the brain, has an internal fibrous structure that allows water to diffuse more rapidly in alignment with the fibers. Changes in the water diffusion pattern indicate changes in the fiber structure which can result from damage to the fibers. Measurements of the water diffusion patterns include overall diffusivity, Apparent Diffusion Coefficient (ADC), and the linear component of the ADC known as the Fractional Anisotropy (FA). The purpose of this study is three fold: (1) to evaluate the reproducibility of ADC and FA values obtained from the same dataset between two Diffusion Tensor Imaging analysis software packages (Analyze 10.0 and Philips PRIDE), (2) to use the results of the Analyze 10.0 software analysis to characterize the corpus callosum (CC) and anatomical regions of the CC from a dataset of control subjects with no known anatomical abnormalities obtained via 3.0 Tesla (3T) MRI, and (3) to identify and characterize patterns present in ADC and FA values of subjects with known anatomical abnormalities by comparing the results to the control datasets. In this DTI software analysis study, Analyze 10.0 produced significantly different results for mean ADC and mean FA when compared to the PRIDE software package. Pearson correlation values show that Analyze 10.0 provides reliably similar mean ADC and mean FA values. Regardless of the software package, gender and age of the subjects did not provide significantly different values for mean ADC and mean FA. Using results from Analyze 10.0 on the control group, provides a baseline of comparison for subjects with CO, MS, or TBI diagnosis. Comparisons of seven anatomical and physiological regions of the CC between control and non-control subjects show that medial regions of the CC (AMB, PMB, Isthmus 1 and Isthmus 2) are most likely to show significant differences in mean ADC and FA; while the genu and splenium regions are less likely to show significant differences.

Keywords

Biological sciences; Brain — Wounds and injuries; Carbon monoxide — Physiological effect; Carbon monoxide poisoning; Corpus callosum; Diffusion magnetic resonance imaging; Diffusion tensor imaging; Health and environmental sciences; Multiple sclerosis; Traumatic brain injury

Disciplines

Analytical, Diagnostic and Therapeutic Techniques and Equipment | Investigative Techniques | Medical Biophysics | Neurosciences

Language

English


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