Radiology Commons^™

Non-Invasive Imaging For The Assessment Of Cardiac Dose And Function Following Focused External Beam Irradiation, Omar El-Sherif

Electronic Thesis and Dissertation Repository

Technological advances in imaging and radiotherapy have led to significant improvement in the survival rate of breast cancer patients. However, a larger proportion of patients are now exhibiting the less understood, latent effects of incidental cardiac irradiation that occurs during left-sided breast radiotherapy. Here, we examine the utility of four-dimensional computed tomography (4D-CT) for the accurate assessment of cardiac dose; and a hybrid positron emission tomography (PET) magnetic resonance imaging (MRI) system to longitudinally study radiation-induced cardiac effects in a canine model.

Using 4D-CT and deformable dose accumulation, we assessed the variation caused by breathing motion in the estimated dose …

Role Of Cerebrovascular Abnormality In Neurodegenerative Disease And Subcortical Ischemic Disease: Ct Perfusion And Pet Imaging, Jun Yang

Electronic Thesis and Dissertation Repository

Clinical studies indicate that about 30% ~ 50% of patients have cognitive impairment after the first or recurrent stroke. Ischemic injury, particularly subcortical lesions, caused by stroke has been demonstrated to further exacerbate cognitive impairment of Alzheimer’s disease (AD) and vascular dementia. However, the mechanisms whereby cerebrovascular abnormalities contribute to neurodegeneration at early stage of disease and eventually to cognitive decline remain unclear. CT perfusion and positron emission tomography (PET) were used to investigate early mechanisms in a rat comorbid model of cerebral ischemia (CI) and β-amyloid (Aβ, a pathological hallmark of AD) toxicity, and in patients with small subcortical …