Shan Tan

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OBJECTIVES The aim of this study was to investigate whether an objective measure of freezing of gait (FOG) using a validated alternating stepping in place (SIP) task, is related to executive and/or visuospatial cognitive impairment in Parkinson's disease (PD). METHODS We studied prospectively 30 PD subjects with the Unified Parkinson's Disease Rating(More)
BACKGROUND Colonic migrating motor complexes in the rat constitute two distinct propulsive motor patterns, pan-colonic rhythmic long distance contractions (LDCs), and rhythmic propulsive motor complexes (RPMCs) occurring primarily in the mid/distal colon. Interstitial cells of Cajal govern their rhythmicity, but their occurrence is dependent on neural(More)
BACKGROUND We investigated the relationship of standardized uptake values (SUVs) to radiobiological parameters, such a 25 s tumor control probability (TCP), to allow for quantitative prediction of tumor response based on SUVs from (18)F fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET) before and after treatment for esophageal cancer. (More)
Accumulated evidence suggests that enhanced neurogenesis stimulated by ischemic injury contributes to stroke outcome. However, it is unclear whether hyperglycemia, which is frequently tested positive in patients with acute ischemic stroke, influences stroke-induced neurogenesis. The aim of the present study is to examine the effect of hyperglycemia on(More)
PURPOSE To design a reliable method to determine the optimal parameter in the adaptive region-growing (ARG) algorithm for tumor segmentation in PET. METHODS The ARG uses an adaptive similarity criterion m - fσ ≤ I_PET ≤ m + fσ, so that a neighboring voxel is appended to the region based on its similarity to the current region. When increasing the relaxing(More)
PURPOSE To study the influence of different regions of interest (ROI) on tumor segmentation in PET. METHODS The experiments were conducted on a cylindrical phantom. Six spheres with different volumes (0.5ml, 1ml, 6ml, 12ml, 16ml and 20 ml) were placed inside a cylindrical container to mimic tumors of different sizes. The spheres were filled with 11C(More)
OBJECTIVE To study whether subvolumes with a high pre-chemoradiotherapy (CRT) FDG uptake could identify residual metabolically-active volumes (MAVs) post-CRT within individual esophageal tumors. Accurate identification will allow simultaneous integrated boost to these subvolumes at higher risk to improve clinical outcomes. METHODS Twenty patients with(More)
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