Search

To purchase or authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1552-6569.2007.00158.x Byline: Xiang-yan Chen (1), Wynnie Wai Man Lam (1), Ho Keung Ng (1), Yu-hua Fan (1), Ka Sing Wong (1) Keywords: Ischemic stroke; calcification; intracranial artery; atherosclerosis; risk factors; multi-detector-row computed tomography (MDCT) Abstract: ABSTRACT BACKGROUND AND PURPOSE Calcification in cerebral arteries is understudied, although frequently observed on computed tomography of the brain (CT brain). We aimed to assess the incidence of intracranial artery calcification in ischemic stroke patients and to evaluate its correlation with ischemic stroke. METHODS Our study included ischemic stroke patients and age-gender-matched nonischemic stroke patients referred for CT brain. RESULTS One hundred and seventy-five ischemic stroke patients and 182 controls were enrolled. The highest prevalence of calcification was seen in intracranial internal carotid artery (IICA) (80.4%), and less commonly in the vertebral artery (35.6%). There was a higher prevalence of intracranial artery calcification in ischemic stroke patients than controls (92.6% vs. 76.4%, P < .001). Hypertension (OR = 2.056, 95% CI: 1.129 [proportional to] 3.745), diabetes (OR = 2.483, 95% CI: 1.233 [proportional to] 5.001), smoking (OR = 2.844, 95% CI: 1.542 [proportional to] 5.243), intracranial artery calcification (OR = 3.172, 95% CI: 1.252 [proportional to] 8.036), hyperlipidemia (OR = 6.714, 95% CI: 3.302 [proportional to] 13.650), and atrial fibrillation (OR = 7.941, 95% CI: 2.790 [proportional to] 22.599) were found to be independently associated with ischemic stroke. CONCLUSIONS We demonstrated a higher incidence of intracranial artery calcification in ischemic stroke patients. Besides traditional risk factors, intracranial artery calcification was found to be an independent risk factor of ischemic stroke. Author Affiliation: (1)Department of Anatomical & Cellular Pathology (X-YC, HKN); Department of Diagnostic Radiology & Organ Imaging (WWML); and Department of Medicine & Therapeutics, The Chinese University of Hong Kong, Shatin, Hong Kong SAR (Y-HF, KSW). Article History: Acceptance: Received January 10, 2007, and accepted for publication January 22, 2007. Article note: Correspondence: Address correspondence to K.S. Wong, MD, Department of Medicine & Therapeutics, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong. E-mail: ks-wong@cuhk.edu.hk.

To purchase or authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1552-6569.2006.00048.x Byline: Xiang-Yan Chen (1), Wynnie Wai Man Lam (1), Ho Keung Ng (1), Hai-Lu Zhao (1), Ka Sing Wong (1) Keywords: Middle cerebral artery; magnetic resonance imaging; postmortem study; histology; diagnosis Abstract: ABSTRACT Background and Purpose. Magnetic resonance imaging (MRI) has been widely applied in detecting intracranial large artery stenosis, but there have been few validation studies to compare with histopathology. The aim of the postmortem study is to assess the accuracy of MRI in identifying middle cerebral artery (MCA) stenosis. Methods. We recruited, consecutively, Chinese postmortem autopsies in our hospital during 19 months. MRI was performed in the postmortem brains to scan the cross-sections of MCAs with barium expanding the artery lumen. The MCAs were then removed for histopathologic studies. With histopathology as a reference standard, the accuracy of MRI was evaluated, and the correlation between MCA stenosis identified by MRI and radiologically or histopathologically evident brain infarcts was investigated. Results. Seventy-six consecutive autopsies were recruited. The sensitivity and specificity of MRI in detecting more than 30% MCA stenosis were 38.6% and 92.2%, with a positive predictive value of 87.2% and negative predictive value of 52.2%, and the corresponding values of MRI in identifying more than 50% MCA stenosis were 57.1%, 90.8%, 50%, and 83.0%, respectively. Both more than 30% and more than 50% MCA stenosis identified by MRI were found to be associated with infarctions in the corresponding MCA territory (P= 0.001, odds ratio = 4.365, 95% CI: 1.684-11.313; and P= 0.039, odds ratio = 2.694, 95% CI: 1.139-6.377). Conclusions. Our study demonstrates the agreement between ex vivo MRI and histopathology in identifying MCA stenosis, and the correlation between the MCA stenosis identified by MRI and radiologically or histopathologically evident brain infarcts. Author Affiliation: (1)From the Department of Anatomical and Cellular Pathology (X-Y C, HKN); Department of Diagnostic Radiology and Organ Imaging (WL); and Department of Medicine and Therapeutics, Chinese University of Hong Kong, Shatin, Hong Kong SAR (H-LZ, KSW). Article History: Received January 04, 2006, and in revised form March 14, 2006. Accepted for publication March 22, 2006. Article note: Address correspondence to Ka Sing Wong, MD, Department of Medicine and Therapeutics, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong. E-mail: ks-wong@cuhk.edu.hk.

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ahj.2004.10.042 Byline: Nina Man-ching So (a), Wynnie Wai-man Lam (a), Debiao Li (c), Anna Kin-Yin Chan (b), John Elsby Sanderson (b), Constantine Metreweli (a) Abstract: The aim of the study was to compare the detection of clinically significant coronary artery stenosis using a magnetic resonance 3-dimensional (3D) breath-hold true fast imaging with steady-state precession (trueFISP) sequence with conventional coronary angiography. Author Affiliation: (a) Department of Diagnostic Radiology and Organ Imaging, The Chinese University of Hong Kong, Hong Kong, China (b) Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong, China (c) Department of Radiology, Northwestern University, Chicago, Ill Article History: Received 10 February 2004; Accepted 26 October 2004

We studied the utility of pancreatic magnetic resonance imaging (MRI) in 72 thalassemia major patients (21 diabetic, 51 normoglycemic). Diabetic patients were significantly older (p<0.0001) and had smaller pancreas volume (p<0.0001). The two groups were comparable for ferritin and MRI-T2* heart, liver and pancreas. Pancreatic T2* signals were abnormal in 80% of both groups, and correlated with heart T2*. In normoglycemic patients, cardiac T2* and log-pancreatic T2* values correlated with homeostatic model assessments HOMA-B (beta cell reserve), HOMA-IR (insulin resistance) and fasting insulin/C-peptide levels. This suggested that improved chelation may improve beta cell reserve and prevent pancreatic atrophy.

Objective: To assess the prognostic value of computed tomography (CT) in hyperacute middle cerebral artery (MCA) infarcts., Methods: The CT features, total CT score, and National Institutes of Health Stroke Scale (NIHSS) score were correlated with the 30-day mortality in 16 patients with a hyperacute MCA infarct., Results: Admission NIHSS scores were significantly lower in the survival group (P = 0.016). The extent of infarct, attenuation of corticomedullary differentiation, and total CT score were associated with 30-day mortality (P < 0.05). In prediction of mortality, extent of an infarct > 67% gave sensitivity, specificity, positive predictive value, and negative predictive value rates of 86%, 100%, 100%, and 90%, respectively. Attenuation of corticomedullary differentiation gave sensitivity, specificity, positive predictive value, and negative predictive value rates of 86%, 89%, 86%, and 89%, respectively. An NIHSS score > 28 gave sensitivity, specificity, positive predictive value, and negative predictive value rates of 86%, 67%, 67%, and 86%, respectively. A CT score > 4 gave sensitivity, specificity, positive predictive value, and negative predictive value rates of 86%, 78%, 75%, and 88%, respectively., Conclusions: Computed tomography features and the admission NIHSS score are important predictors of survival in hyperacute extensive MCA infarcts.