Biomedical subjects

K T Wong

Publications and source records attributed to K T Wong.

At least 19 recordsLinked to original sources

PubMed2007

Features discriminating SARS from other severe viral respiratory tract infections.

This study investigated the discriminatory features of severe acute respiratory syndrome (SARS) and severe non-SARS community-acquired viral respiratory infection (requiring hospitalization) in an emergency department in Hong Kong. In a case-control study, clinical, laboratory and radiological data from 322 patients with laboratory-confirmed SARS from the 2003 SARS outbreak were compared with the data of 253 non-SARS adult patients with confirmed viral respiratory tract infection from 2004 in order to identify discriminatory features. Among the non-SARS patients, 235 (93%) were diagnosed as having influenza infections (primarily H3N2 subtype) and 77 (30%) had radiological evidence of pneumonia. In the early phase of the illness and after adjusting for baseline characteristics, SARS patients were less likely to have lower respiratory symptoms (e.g. sputum production, shortness of breath, chest pain) and more likely to have myalgia (p < 0.001). SARS patients had lower mean leukocyte and neutrophil counts (p < 0.0001) and more commonly had "ground-glass" radiological changes with no pleural effusion. Despite having a younger average age, SARS patients had a more aggressive respiratory course requiring admission to the ICU and a higher mortality rate. The area under the receiver operator characteristic curve for predicting SARS when all variables were considered was 0.983. Using a cutoff score of >99, the sensitivity was 89.1% (95%CI 82.0-94.0) and the specificity was 98.0% (95%CI 95.4-99.3). The area under the receiver operator characteristic curve for predicting SARS when all variables except radiological change were considered was 0.933. Using a cutoff score of >8, the sensitivity was 80.7% (95%CI 72.4-87.3) and the specificity was 94.5% (95%CI 90.9-96.9). Certain clinical manifestations and laboratory changes may help to distinguish SARS from other influenza-like illnesses. Scoring systems may help identify patients who should receive more specific tests for influenza or SARS.

Adolescent↗

PubMed2006

Frequency and clinical determinants of poststroke cognitive impairment in nondemented stroke patients.

The objective of this study was to examine the prevalence and clinical correlates of poststroke cognitive impairment in Chinese stroke patients in Hong Kong. One hundred seventy-nine stroke patients were interviewed by a psychiatrist 3 months after their stroke. Cognitive impairment was determined according to the Mini-Mental State Examination score. Thirty-nine participants (21.8%) had cognitive impairment. Univariate analysis found that cognitive impairment was associated with age, female sex, level of education, previous stroke, prestroke Rankin score, National Institutes of Health Stroke Scale dysarthria and total scores, urinary incontinence, and cerebral atrophy index. Multivariate logistic regression suggested that female sex, education, National Institutes of Health Stroke Scale dysarthria score, urinary incontinence, and atrial fibrillation were independent risk factors of poststroke cognitive impairment. After removal of 54 patients with previous stroke from the sample, the frequency of cognitive impairment decreased to 18.4%. It was concluded that cognitive impairment is common among nondemented Chinese stroke patients in Hong Kong.

Age Factors↗

PubMed2006

Biopsy of deep-seated head and neck lesions under intraoral ultrasound guidance.

Although transcutaneous ultrasound combined with fine-needle aspiration is often used as initial modality for evaluating superficial neck masses, its role in management of deep-seated neck masses is limited. Intraoral ultrasound and guided biopsy helps in obtaining tissue from deep-seated neck masses for an accurate histologic diagnosis, providing useful information in treatment planning. This article discusses the role of intraoral ultrasound and presents 3 cases in which biopsy of deep-seated neck masses under intraoral ultrasound guidance helped in diagnosis and management.

Adenoma, Pleomorphic↗

PubMed2005

Ultrasound of thyroid cancer.

The management of thyroid nodules is multi-disciplinary and involves head and neck surgeons, pathologists and radiologists. Ultrasound is easy to perform, widely available, does not involve ionizing radiation and is readily combined with fine needle aspiration cytology (FNAC). It is therefore an ideal investigation of choice for evaluating thyroid nodules. It evaluates specific features that help in identifying the nature of the nodule and FNAC helps in diagnostic accuracy. In addition, following treatment for thyroid cancer ultrasound provides a safe tool for disease surveillance. This paper discusses the role of ultrasound in the management of patients with thyroid cancer.

Biopsy, Fine-Needle↗

PubMed2005

Determinants of prestroke cognitive impairment in stroke associated with small vessel disease.

Understanding the determinants of prestroke cognitive impairment (PCI) in stroke associated with small vessel disease (SVD) may shed light on how to prevent further cognitive deterioration after stroke. We administered the Informant Questionnaire on Cognitive Decline (IQCODE) to close informants of 78 consecutive stroke patients who had SVD. PCI, as defined by an average score of IQCODE > or =3.4 was found in 19 (24%) patients. Regression analyses were performed on the following risk factors for PCI: age, years of education, gender, previous stroke, volume of white matter changes, measures of silent lacunes, cerebral atrophy index, medial temporal lobe atrophy and frontal lobe atrophy. Multivariate regression analyses revealed that only cerebral atrophy index (OR 1.5, CI 1.2-1.9, p < 0.001) predicted PCI among patients with SVD.

Aged↗

PubMed2005

Imaging for thyroglossal duct cyst: the bare essentials.

Thyroglossal duct cyst is the most common congenital cyst in the head and neck, and imaging features have been well documented in the literature. However, there are several practical important points to bear in mind during preoperative imaging, which are often overlooked. This review aims to summarize the imaging findings and emphasize important points for trainees and radiologists, particularly those who may encounter this lesion infrequently.

Adult↗

PubMed2005

Impact of severe acute respiratory syndrome (SARS) on pulmonary function, functional capacity and quality of life in a cohort of survivors.

OBJECTIVE: To examine the impact of severe acute respiratory syndrome (SARS) on pulmonary function, exercise capacity, and health-related quality of life (HRQoL) among survivors. METHODS: 110 survivors with confirmed SARS were evaluated at the Prince of Wales Hospital, HK at the end of 3 and 6 months after symptom onset. The assessment included lung volumes (TLC, VC, RV, FRC), spirometry (FVC, FEV1), carbon monoxide transfer factor (TLCO adjusted for haemoglobin), inspiratory and expiratory respiratory muscle strength (Pimax and Pemax), 6 minute walk distance (6MWD), chest radiographs, and HRQoL by SF-36 questionnaire. RESULTS: There were 44 men and 66 women with a mean (SD) age of 35.6 (9.8) years and body mass index of 23.1 (4.8) kg/m2. Seventy (64%) were healthcare workers. At 6 months 33 subjects (30%) had abnormal chest radiographs; four (3.6%), eight (7.4%), and 17 (15.5%) patients had FVC, TLC, and TLCO below 80% of predicted values; and 15 (13.9%) and 24 (22.2%) had Pimax and Pemax values below 80 cm H2O, respectively. The 6MWD increased from a mean (SD) of 464 (83) m at 3 months to 502 (95) m (95% CI 22 to 54 m, p<0.001), but the results were lower than normal controls in the same age groups. There was impairment of HRQoL at 6 months. Patients who required ICU admission (n = 31) had significantly lower FVC, TLC, and TLCO than those who did not. CONCLUSION: The exercise capacity and health status of SARS survivors was considerably lower than that of a normal population at 6 months. Significant impairment in surface area for gas exchange was noted in 15.5% of survivors. The functional disability appears out of proportion to the degree of lung function impairment and may be related to additional factors such as muscle deconditioning and steroid myopathy.

Adult↗

PubMed2005

Salivary gland tumors at in vivo proton MR spectroscopy.

PURPOSE: To prospectively evaluate whether proton magnetic resonance (MR) spectroscopy can be used to characterize salivary gland tumors (SGTs). MATERIALS AND METHODS: Ethics committee approval and informed consent were obtained. Hydrogen 1 ((1)H) MR spectroscopy was performed with echo times of 136 and 272 msec at 1.5 T in both SGTs and normal parotid glands. Spectra were analyzed in the time domain by using prior knowledge in the fitting procedure to obtain peak amplitudes of choline (Cho), creatine (Cr), and unsuppressed water. Mean Cho/Cr and Cho/water ratios for each subgroup of SGTs were obtained, and results were compared by using a nonparametric t test. RESULTS: Successful spectra were acquired in 56 patients (35 men, 21 women; mean age, 56 years) with a total of nine malignant tumors and 47 benign SGTs (24 Warthin tumors, 22 pleomorphic adenomas, one oncocytoma). At an echo time of 136 msec, Cho/Cr ratios were obtained in 26 (47%) of 55 spectra, with a mean value (+/- standard deviation) of 1.73 +/- 0.47, 5.49 +/- 1.86, 3.46 +/- 0.84, and 2.45 for malignant tumors, Warthin tumors, pleomorphic adenomas, and oncocytoma, respectively. Differences were significant between Warthin tumors and pleomorphic adenomas (P = .028) and between benign SGTs and malignant tumors (P < .001). At an echo time of 272 msec, Cho/Cr ratios were obtained in 16 (30%) of 53 spectra, with a mean value of 2.27 +/- 0.69, 6.92 +/- 1.47, and 3.67 +/- 1.23 for malignant tumors, Warthin tumors, and pleomorphic adenomas, respectively. Differences were also significant between Warthin tumors and pleomorphic adenomas (P = .041) and benign SGTs and malignant tumors (P = .004). There was a significant difference in mean Cho/water ratio for Warthin tumors versus pleomorphic adenomas at echo times of 136 msec (P = .003) and 272 msec (P = .002) but not for benign SGTs versus malignant tumors. CONCLUSION: (1)H MR spectroscopy may be used to characterize SGTs, but a larger study is required to validate these initial results.

Adult↗

PubMed2005

Poststroke depression in Chinese patients: frequency, psychosocial, clinical, and radiological determinants.

This study attempted to evaluate the psychosocial, clinical, and radiological predictors of poststroke depression (PSD) in Chinese patients. One hundred eighty-nine patients participated in the study. Three months after the index stroke, a psychiatrist administered the Structured Clinical Interview for DSM-IV to all of the patients and made a DSM-IV diagnosis of depression. In addition, a host of demographic, clinical, and radiological variables were examined. Thirty-one (16.4%) of the patients had a diagnosis of PSD that included major depression (n=11, 5.8%,), minor depression (n=16, 8.5%), or dysthymia (n=4, 2.1%). Univariate analysis revealed that PSD was associated with female gender, a lower level of education, a lower Lubben Social Network Scale (LSNS) score, subcortical infarcts, and lesions in the anterior cerebral artery (ACA) territory, and the Modified Life Event Scale (MLES) score was borderline for statistical significance. Multivariate logistic regression analysis suggested that female gender, a high MLES score, and subcortical and ACA lesions were independent risk factors for PSD and that a high LSNS score was a protective factor.

Aged↗

PubMed2005

Neuroimaging determinants of cognitive performances in stroke associated with small vessel disease.

BACKGROUND AND PURPOSE: Controversies still exist as to the neuroimaging determinants of cognitive impairment in cerebral small vessel disease (SVD). The authors studied the neuroimaging correlates of cognitive performances among patients with stroke associated with SVD. METHODS: The authors per formed cerebral computed tomography, magnetic resonance imaging, and diffusion-weighted imaging among 74 consecutive patients admitted to the acute stroke unit because of stroke associated with SVD. They examined the association between cognitive performances and the following neuroimaging features: volume of white matter changes (WMC), multiplicity of lacunae, location of lacunae, total cerebral atrophy, and frontal and medial temporal lobe atrophy. RESULTS: Apart from age and education, univariate linear regression analyses revealed that WMC volume, presence of thalamic lacunae, cerebral atrophy, and left frontal lobe atrophy predicted performance on the Mini-Mental State Examination while WMC volume, presence of thalamic infarcts, cerebral atrophy, and frontal lobe atrophy of both sides predicted performance on the Mattis Dementia Rating Scale-Initiation/Preservation subscale. In the multivariate analyses, education (R2=0.22, P<.001), left frontal lobe atrophy (R2=0.10, P=.004), and presence of thalamic lacunae (R2=0.04, P=.049) were found to predict performance on the Mini-Mental State Examination while age (R2=0.23, P<.001) and presence of thalamic lacunae (R2=0.08, P=.011) were found to predict performance on the Mattis Dementia Rating Scale-Initiation/Preservation. CONCLUSIONS: Among patients with stroke associated with SVD, thalamic lacunae and frontal lobe atrophy are key determinants of cognitive performances.

Age Factors↗

PubMed2005

Diseases of the submandibular gland as demonstrated using high resolution ultrasound.

In this review the high resolution ultrasound appearances of the normal anatomy and pathology involving the submandibular gland are demonstrated. The submandibular gland is affected by a number of disease processes that may be difficult to distinguish clinically. Its superficial location makes it ideal for ultrasound evaluation and a useful adjunct to clinical examination. In the assessment of submandibular pathology ultrasound allows intraglandular and extraglandular lesions to be localized and differentiated. These lesions can be further characterized as being benign or malignant and the extent of any extraglandular extension determined. Ultrasound is the first-line investigation in the assessment of sialolithiasis due to its high specificity and sensitivity. In severe infective sialadenitis ultrasound can confirm the presence and guide drainage of abscesses. Ultrasound also has an important role in the assessment of chronic inflammatory disorders such as sarcoidosis and Sjogren's syndrome.

Acute Disease↗

PubMed2004

Severe acute respiratory syndrome: correlation between clinical outcome and radiologic features.

PURPOSE: To evaluate whether there is a correlation between the clinical outcomes and radiologic features of severe acute respiratory syndrome (SARS). MATERIALS AND METHODS: The clinical, laboratory, and radiologic features of 138 patients with SARS were analyzed. Three radiologists in consensus retrospectively assessed the frontal chest radiographs obtained at presentation and during treatment (n = 2045) for the distribution (each lung was divided into upper, middle, and lower zones) and extent of lung parenchymal abnormality. Clinical end points included intensive care unit (ICU) admission and death. RESULTS: Thirty-six (26.1%) patients required ICU care, and eight (5.8%) died. The patients who required ICU care and/or died had more extensive consolidation on chest radiographs obtained initially (median percentage of consolidation, 3.30%, with interquartile range [IR] of 1.70%-8.78% vs 1.70% [IR, 0%-3.30%]; P < .001) and on day 7 after fever onset (median percentage of consolidation, 15.00% [IR, 6.48%-28.73%] vs 5.00% [IR, 2.50%-7.50%]; P < .001) than did surviving patients who did not require ICU care. Patients with involvement of more than one lung zone on initial and day 7 chest radiographs were more likely to require ICU care and/or die than were those with involvement of one or fewer zones (P < .001). Patients with bilateral pneumonic changes at presentation were more likely to have an adverse outcome than were those with unilateral pneumonia (P < .001). Involvement of more than one lung zone at baseline chest radiography was an independent predictor of ICU admission and/or death (odds ratio, 3.16; 95% confidence interval: 1.07, 9.32; P = .037) after adjustments for other significant factors (ie, patient age, and baseline neutrophil count and lactate dehydrogenase level). CONCLUSION: More extensive airspace disease at presentation is an independent predictor of adverse outcome in patients with SARS.

Adult↗

PubMed2004

Impact of applying NINDS-AIREN criteria of probable vascular dementia to clinical and radiological characteristics of a stroke cohort with dementia.

BACKGROUND: There are no data concerning the relative representation of clinical vascular risk factors and radiological lesions in cases that have been ruled in and ruled out for probable vascular dementia (VaD) according to NINDS-AIREN criteria. METHODS: Three months after their index stroke, a psychiatrist interviewed patients and made a diagnosis of VaD according to both DSM-IV and NINDS-AIREN criteria for probable VaD. Patients who fulfilled the DSM-IV criteria for VaD were divided into two groups: those who were ruled in and ruled out according to NINDS-AIREN criteria as probable VaD. Demographic characteristics, vascular risk factors, clinical features of the index stroke and radiological findings were then compared between the two groups. RESULTS: Of the 297 patients screened, 56 (18.8%) had a DSM-IV diagnosis of dementia. Among these demented patients, 55 (98.2%) and 22 (39.3%) fulfilled DSM-IV and NINDS-AIREN diagnosis of VaD, respectively. The concordance and level of agreement (kappa statistic) between DSM-IV and NINDS-AIREN diagnoses were 40% and 0.02, respectively. Reasons of failure to meet NINDS-AIREN criteria included the lack of temporal relationship between dementia and stroke (n = 20), the absence of focal neurological signs and/or radiological evidence of stroke (n = 6) and both of the above (n = 7). There was no significant difference between the above two groups in terms of demographic data, features of index stroke, vascular risk factors and CT scan findings, except that leukoaraiosis (p = 0.021) and bilateral lesions (p = 0.015) were more frequent in subjects diagnosed according to NINDS-AIREN criteria of probable VaD. The difference between these two groups with respect to the number of lesions was borderline for significance (p = 0.052). CONCLUSIONS: The use of NINDS-AIREN criteria for VaD for case selection in poststroke dementia research may exclude a number of subjects with VaD.

Acute Disease↗

PubMed2004

Frequency and determinants of poststroke dementia in Chinese.

BACKGROUND AND PURPOSE: Both dementia and stroke are major health problems in Chinese societies. Stroke is a frequent cause of dementia. Only a few studies have been published on poststroke dementia (PSDE), none of which has investigated a consecutive stroke cohort in Asian patient populations. The objective of this study was to examine the prevalence and clinical correlates of PSDE in Chinese stroke patients in Hong Kong. METHODS: Two hundred eighty stroke patients consecutively admitted to the medical wards of a university-affiliated regional hospital were interviewed by a psychiatrist 3 months after stroke. The presence of dementia and vascular dementia was diagnosed according to the Diagnostic and Statistical Manual, 4th edition. In addition, a wide range of demographic and clinical variables were examined. RESULTS: Fifty-five participants (20%) had PSDE. Univariate analysis found that PSDE was associated with age; level of education; prestroke Rankin Scale score; prestroke Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) score; National Institutes of Health Stroke Scale (NIHSS) best language score, dysarthria score, and total score; urinary incontinence; cortical infarct; leukoaraiosis; bilateral lesions; number of lesions; involvement of middle cerebral artery circulation; and cerebral atrophy index. Multivariate logistic regression suggested that prestroke IQCODE score, NIHSS total score, leukoaraiosis, involvement of middle cerebral artery territory, and cerebral atrophy index were independent risk factors of PSDE. After removal of 22 patients with prestroke dementia, which was defined as a prestroke IQCODE score > or =4.0, the frequency of PSDE dropped to 15.5%. Furthermore, involvement of the middle cerebral artery territory and cerebral atrophy index were replaced by level of education and bilateral lesions as independent predictors in the final logistic model. CONCLUSIONS: PSDE is common among Chinese stroke patients in Hong Kong. Its frequency is comparable to that in white populations. The clinical determinants of PSDE, after the exclusion of patients with prestroke dementia, include premorbid level of cognitive function, severity of stroke, leukoaraiosis, level of education, and bilateral lesions.

Aged↗

PubMed2004

Frequency and determinants of prestroke dementia in a Chinese cohort.

Pre-existing dementia among patients with acute stroke is common, and adversely affects outcomes. Only a few studies have been published on prestroke dementia (PSD), none of which have investigated a consecutive stroke cohort in an Asian patient population. The objective of this study was to examine the prevalence and clinical correlates of PSD in Chinese stroke patients in Hong Kong. Close and reliable informants of 289 stroke patients who were consecutively admitted to the medical wards of a university-affiliated regional hospital completed the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) within 1 week after their relative's admission. The presence of PSD was defined as an average IQCODE score of >or= 4.00. In addition, a wide range of demographic and clinical variables were examined and recorded.Twenty-two participants (7.6%) had PSD. The frequency of PSD in the group of subjects (n = 73) who were assessed within 48 hours after their admission was 12.3%. Univariate analysis found that PSD was associated with age, marital status, atrial fibrillation (AF), previous transient ischaemic attack (TIA), leukoaraiosis, and cerebral atrophy index (CAI). Multivariate logistic regression suggested that CAI, age, AF, and past TIA were independent risk factors for PSD. The low prevalence of PSD in Chinese patients in comparison with their Caucasian counterparts may be due to the difference in the time frame of the assessment. Comparative studies involving both Caucasian and Chinese stroke patients are required to further explore the role of AF and TIA in the development of PSD in both Chinese and Caucasian patients.

Adolescent↗

PubMed2004

Imaging for primary hyperparathyroidism--what beginners should know.

For patients with primary hyperparathyroidism surgical removal of the hyperfunctioning parathyroid gland is curative. With advances in minimally invasive surgery, accurate pre-operative localization of the hyperfunctioning parathyroid tissue is essential to aid successful surgical treatment. The onus of identifying this hyperfunctioning parathyroid tissue therefore falls on imaging techniques such as high-resolution ultrasound, radionuclide imaging, computed tomography and magnetic resonance imaging. This article is not an exhaustive review, and its main aim is to familiarize the general radiologist, trainee radiologists and clinicians with the basics of various imaging techniques and their roles in practical management of patients with primary hyperparathyroidism.

Diagnostic Imaging↗

PubMed2004

Sonographic assessment of the submandibular space.

There is a wide variety of pathological processes which may present with swelling in the submandibular space. Although the submandibular gland is the most important structure in this region, there are a number of extraglandular causes of swelling which frequently mimic submandibular gland enlargement. In this review the use of high-resolution ultrasound in the assessment of the submandibular gland and adjacent structures is discussed and illustrated.

Humans↗

PubMed2004

Effects of early corticosteroid treatment on plasma SARS-associated Coronavirus RNA concentrations in adult patients.

BACKGROUND: The effect of corticosteroid treatment on the viral load of Severe Acute Respiratory Syndrome (SARS) patients is unknown. OBJECTIVE: To compare the plasma SARS-CoV RNA concentrations in ribavirin-treated patients who received early hydrocortisone therapy with those who received placebo. STUDY DESIGN: Serial plasma SARS-CoV RNA concentrations measured in the setting of a prospective, randomized double-blinded, placebo-controlled trial designed to assess the efficacy of "early" (<7 days of illness) hydrocortisone use in previously healthy SARS patients were analyzed. SARS-CoV RNA was quantified using a one-step real-time RT-PCR assay targeting the nucleocapsid gene. RESULTS: Among 16 non-ICU cases, SARS-CoV RNA was detected in plasma since day 3-4 after fever onset; viral concentration peaked in the first week, which then rapidly declined in the second week of illness. On days 8, 12, 16, and 20, the cumulative proportion of patients with undetectable virus in plasma was 31%, 69%, 92%, and 100%, respectively. Plasma SARS-CoV RNA concentrations in the second and third week of illness were significantly higher in patients who received initial hydrocortisone treatment (n = 9), as compared to those who received placebo (n = 7)(AUC; Mann-Whitney, P = 0.023). The median time for SARS-CoV to become undetectable in plasma was 12 days (11-20 days) versus 8 days (8-15 days), respectively. CONCLUSION: Our findings suggested "early" corticosteroid treatment was associated with a higher subsequent plasma viral load.

Adrenal Cortex Hormones↗