Ting Yim Lee

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RATIONALE AND OBJECTIVES Deconvolution-based software can be used to calculate quantitative maps of cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) from first-pass computed tomography perfusion (CTP) datasets. The application of this software requires the user to select multiple input variables. The purpose of this study(More)
We have developed an in vivo method of measuring the blood-brain transfer constant (K) of iopamidol and the cerebral plasma volume (Vp) in brain tumors using a clinical X-ray CT scanner. In patient studies, Isovue 300 (iopamidol) was injected at a dosage of 1 ml/kg patient body weight. Serial CT scans of the tumor site and arterial blood samples from a(More)
Tumor blood-brain transfer constant of iopamidol (K) and plasma volume (Vp) were measured in 10 patients with primary brain tumors before and after 7 days of dexamethasone treatment (4 x 4 mg per oral per day) using X-ray computed tomography. Both K and Vp decreased significantly after dexamethasone treatment with p < 0.01 and 0.09 respectively according to(More)
In a porcine ischemic stroke model, we sought to compare the acute predicted infarct core volume (PIV) defined by CT perfusion (CTP)-hemodynamic parameters and MR-diffusion-weighted imaging (MR-DWI)/apparent diffusion coefficient (ADC), with the true infarct core volume (TIV) as defined by histology. Ten Duroc-cross pigs had a CTP scan prior to injection of(More)
Based on the temporal distributions of clustered segments in the time series of the ten Dow Jones US (DJUS) economic sector indices, we calculated their cross and also over 11 corresponding segments within the present financial crisis. From these cross-correlation matrices, we constructed minimal spanning trees (MSTs) of the US economy at the sector level.(More)
The inclusion of dynamic contrast-enhanced computed tomography (CT) or CT perfusion (CTP) scan into the imaging workup for acute stroke patients is widespread. Along with vessel occlusion status from CT angiography, CTP provides pathophysiological information a non-contrast CT cannot provide during the hyperacute stages of cerebral ischemia. Measurement of(More)
We investigated the practical clinical utility of the CT perfusion (CTP) cerebral blood volume (CBV) parameter for differentiating salvageable from non-salvageable tissue in acute ischemic stroke (AIS). Fifty-five patients with AIS were imaged within 6 h from onset using CTP. Admission CBV defect (CBVD) volume was outlined using previously established gray(More)
BACKGROUND Cerebral microvascular abnormality is frequently associated with lacunar and subcortical ischemic lesions. We performed acute and follow-up CT perfusion scans over the first 3 months after ischemic stroke to investigate disturbances of the blood-brain barrier (BBB) and cerebral perfusion in patients with lacunar/subcortical lesions compared to(More)
INTRODUCTION Early brain injury (EBI) can occur within 72 h of aneurysmal subarachnoid hemorrhage (aSAH). The objective of this study was to determine if there are differences in early CTP parameters (<72 h) with respect to delayed cerebral ischemia (DCI), cerebral infarction, and functional outcome. METHODS We performed a prospective cohort study of aSAH(More)
BACKGROUND/OBJECTIVE Clinical evidence indicates that cerebral ischemia (CI) and a pathological factor of Alzheimer's disease, the β-amyloid (Aβ) protein, can increase the rate of cognitive impairment in the ageing population. Using the CT Perfusion (CTP) functional imaging, we sought to investigate the interaction between CI and the Aβ protein on cerebral(More)