Ting-Yim Lee

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PURPOSE To use first-pass perfusion computed tomography (CT) to prospectively investigate tumor vascularity in rectal cancer and to determine whether any of the perfusion parameters would predict tumor response to chemotherapy and radiation therapy. MATERIALS AND METHODS The institutional review board approved this study, and informed prior consent was(More)
PURPOSE To measure mean cerebral blood flow (CBF) in ischemic and nonischemic territories and in low-attenuation regions in patients with acute stroke by using deconvolution-derived hemodynamic imaging. MATERIALS AND METHODS Twelve patients with acute middle cerebral artery stroke and 12 control patients were examined by using single-section computed(More)
0167-7799/02/$ – see front matter ©2002 Elsevier Science Ltd. All rights reserved. PII: S0167-7799(02)02027-9 Ladurner and colleagues [1] were the first to use computed tomography (CT) to study physiological function in the human brain by measuring cerebral blood volume with intravenously injected X-ray contrast agent (an iodinated compound that(More)
PURPOSE To determine the histologic basis of perfusion parameters measured at functional computed tomography (CT) and to examine the relationship between changes in perfusion and changes in histologic parameters after antiangiogenic therapy in a rat model. MATERIALS AND METHODS This study had institutional animal care and use committee approval. Among 20(More)
BACKGROUND AND PURPOSE Compared with MR imaging, dynamic CT perfusion imaging covers only a fraction of the whole brain. An important assumption is that CT perfusion abnormalities correlate with total ischemic volume. The purpose of our study was to measure the degree of correlation between abnormalities seen on CT perfusion scans and the volumes of(More)
The recent "Advanced Neuroimaging for Acute Stroke Treatment" meeting on September 7 and 8, 2007 in Washington DC, brought together stroke neurologists, neuroradiologists, emergency physicians, neuroimaging research scientists, members of the National Institute of Neurological Disorders and Stroke (NINDS), the National Institute of Biomedical Imaging and(More)
OBJECTIVE To differentiate recurrent tumors from radiation effects and necrosis in patients with irradiated brain tumors using perfusion computed tomographic (PCT) imaging. METHODS Twenty-two patients with previously treated brain tumors who showed recurrent or progressive enhancing lesions on follow-up magnetic resonance imaging scans and had a(More)
We propose a new scanning protocol for generating 4D-CT image data sets influenced by respiratory motion. A cine scanning protocol is used during data acquisition, and two registration methods are used to sort images into temporal phases. A volume is imaged in multiple acquisitions of 1 or 2 cm length along the cranial-caudal direction. In each acquisition,(More)
PURPOSE To determine whether admission computed tomography (CT) perfusion-derived permeability-surface area product (PS) maps differ between patients with hemorrhagic acute stroke and those with nonhemorrhagic acute stroke. MATERIALS AND METHODS This prospective study was institutional review board approved, and all participants gave written informed(More)
PURPOSE To systematically evaluate the diagnostic benefits and inter- and intraobserver reliability of an incremental computed tomographic (CT) protocol in the confirmation of clinically suspected stroke, with combined imaging and clinical data as the reference standard. MATERIALS AND METHODS Institutional review board approval was obtained, and(More)