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W C W Chu

Publications and source records attributed to W C W Chu.

At least 19 recordsLinked to original sources
PubMed2006

Curve correction effect of rigid spinal orthosis in different recumbent positions in adolescent idiopathic scoliosis (AIS): a pilot MRI study.

In this pilot cross-sectional study, the effectiveness of rigid spinal orthoses in the correction of spinal curvature of 14 patients with moderate adolescent idiopathic scoliosis (AIS) at different recumbent positions (supine, prone, right and left decubitus) was investigated. Using magnetic resonance (MR) imaging and multi-planar reconstruction technique, evaluation of the scoliotic spine in the coronal, sagittal and axial planes and the effect of spinal orthosis on AIS at different recumbent positions was studied. There was significant reduction of coronal Cobb's angle (p < 0.05) with bracing at all four recumbent positions and the maximal reduction was found in the prone position (18% reduction). The sagittal Cobb's angle was only significantly reduced at the supine position while the axial rotation did not change significantly in all positions.

Adolescent↗
PubMed2006

Role of radiologic features in the management of papillary lesions of the breast.

OBJECTIVE: The purpose of our study was to assess the role of imaging and core biopsy in the management of patients with papillary lesions of the breast. MATERIALS AND METHODS: Clinical records and mammographic and sonographic findings of 40 women with papillary lesions in the breast were retrieved. The imaging features and cytologic findings were correlated with histologic findings. RESULTS: Fifty-six papillary lesions in 40 patients underwent either mastectomy, segmental duct resection, or excision biopsy. There were three papillary carcinomas, 13 papillaryal lesions with carcinoma in situ, one atypical papilloma, four sclerosed papillomata, and 35 papillomata. Of these lesions, 37.5% (21/56) and 82.1% (46/56) could be detected on mammography and sonography, respectively. Galactography and dilated ducts helped to suggest the papillary nature of the lesions. However, mammography and sonography were not able to predict malignancy (sensitivity, 69% and 56%, respectively; specificity, 25% and 90%; positive predictive value [PPV], 60% and 75%; and negative predictive value [NPV], 33% and 90%). Combined interpretation of mammography and sonography gave a sensitivity of 61%, specificity of 33%, PPV of 85%, and NPV of 13%. Fine-needle aspiration gave a sensitivity of 44%, specificity of 68%, PPV of 31%, and NPV of 79%, whereas core biopsy gave a sensitivity of 82%, specificity of 100%, PPV of 100%, and NPV of 83% in the diagnosis of malignancy. CONCLUSION: Radiologic features are not sufficiently sensitive or specific to differentiate benign from malignant papillary lesions. Fine-needle aspiration and core biopsy have pitfalls, and the need for surgical excision of all papillary lesions should be revisited.

Adult↗
PubMed2006

Intravenous leiomyomatosis: computed tomography diagnosis.

Intravenous leiomyomatosis is a rare neoplastic condition characterised by nodular masses of histologically benign smooth muscle growing within veins. In most cases, the disease is confined to the pelvic veins, but involvement may extend to the inferior vena cava and right heart chamber. We report the computed tomography features of a woman who developed extensive intravenous leiomyomatosis and lung metastases, and presented with acute-onset lower limb swelling.

Diagnosis, Differential↗
PubMed2005

Mal-positioned umbilical venous catheter causing liver abscess in a preterm infant.

Neonatal liver abscess is uncommon, carries a high mortality and is difficult to diagnose. We report an unusual case of liver abscess in a preterm infant presenting with abdominal distension and suspected gastrointestinal perforation, rather than the more usual features of fever, hepatomegaly, abdominal tenderness, right-sided pleural effusion, and leukocytosis. We discuss current treatments for neonatal liver abscess and argue that in view of the high mortality and difficulty in diagnosis, prevention should be the primary objective. We believe that mal-positioning the umbilical venous catheter in the liver substantially increases the life-threatening risk of this complication, and advocate extreme care in the placement and use of these catheters.

Catheterization, Peripheral↗
PubMed2005

A case-control study of SARS versus community acquired pneumonia.

The clinical, laboratory, and radiological features at presentation of 16 children (<12 years) with severe acute respiratory syndrome (SARS) and pneumonia were compared with 32 age matched patients with community acquired pneumonia for determination of predictive factors that could allow early differentiation of the two conditions. A definitive contact history was the most important predictor for SARS. Raised serum lactate dehydrogenase concentration in the presence of low neutrophil count and serum creatine phosphokinase level at presentation also indicated an increased likelihood of SARS-coronavirus infection in young children.

Biomarkers↗
PubMed2005

Early computed tomography features in extensive middle cerebral artery territory infarct: prediction of survival.

BACKGROUND: To assess the predictive value of prognosis of different computed tomography (CT) features and National Institutes of Health Stroke Scale score (NIHSS) in acute extensive middle cerebral artery (MCA) infarct. METHODS: Fifty five patients with acute extensive MCA infarct had the CT performed within 24 hours of the onset of symptoms. A total of 11 CT features were analysed. The age distribution, presence of risk factors, presence of individual CT feature, the total CT score, and the NIHSS were correlated with the 30 day mortality. RESULTS: Single explanatory variable analysis showed NIHSS, presence of midline shift, midline shift of more than 1 cm, extent of infarct, presence of hydrocephalus, effacement of subarachnoid space/cella media, attenuation of corticomedullary differentiation, and total CT score were associated with the 30 day mortality. Both extent of infarct >67% and attenuation of corticomedullary differentiation gave a sensitivity and specificity of 93% and 95%, respectively, for the prediction of survival. Logistic regression analysis showed that the extent of infarct and NIHSS were the only independent predictors. CONCLUSIONS: CT features and admission NIHSS are important parameters for prediction of survival in extensive MCA infarct.

Aged↗
PubMed2005

Role of imaging in management of hemophilic patients.

OBJECTIVE: The purpose of this study was to evaluate the role of symptomatology and conventional radiographic scoring in predicting synovial hypertrophy, which could affect the clinical management of hemophilic patients. MATERIALS AND METHODS: Twenty males (mean age, 14.3 years old) with hemophilic arthropathy, including 34 symptomatic joints and 26 asymptomatic joints (16 knees, 20 ankles, and 24 elbows) had conventional radiographs of individual joints obtained that were rated according to the Arnold-Hilgartner stage and the Pettersson score. The patients also underwent MRI for the detection of synovial hypertrophy. The association of synovial hypertrophy and symptomatology was evaluated using the chi-square or Fisher's exact test. The best sensitivity, specificity, and positive and negative predictive values in detection of synovial hypertrophy using symptomatology and radiographic scoring were calculated. RESULTS: A significant association was seen between symptomatology and synovial hypertrophy of the knee and ankle joints (p < 0.05). The sensitivity, specificity, and positive and negative predictive values of symptomatology in detection of synovial hypertrophy of the knee were 100%, 78%, 78%, and 100%, respectively, and for the ankle were 83%, 75%, 83%, and 75%, respectively. The Arnold-Hilgartner stage and Pettersson score of the radiograph had a significant association with synovial hypertrophy of the knee and ankle joints (p < 0.05). Arnold-Hilgartner staging provided a better prediction of synovial hypertrophy, with sensitivity, specificity, positive predictive value, and negative predictive value of 100%, 100%, 100%, and 100% for knees and 82%, 100%, 100%, and 82% for ankles. CONCLUSION: In hemophilic patients, the presence of symptomatology in the knee and ankle joints is associated with synovial hypertrophy, and scoring of the conventional radiographs using Arnold-Hilgartner staging is useful for the prediction of synovial hypertrophy.

Adolescent↗
PubMed2004

Hepatic steatosis in obese Chinese children.

OBJECTIVES THE AIMS OF OUR STUDY WERE: (1) to determine the prevalence of asymptomatic hepatic steatosis and presumed nonalcoholic steatohepatitis, in our local population of obese Chinese children referred for medical assessment; and (2) to assess the correlation between severity of ultrasonographic hepatic steatosis and degree of obesity, insulin resistance and serum biochemical abnormalities. DESIGN: Cross-sectional study. METHODS: In total, 84 obese children, 25 girls and 59 boys with median age and body mass index (BMI) of 12.0 years (interquartile range (IR): 9.5-14.0) and 30.3 kg/m(2) (IR: 27.1-33.4), respectively, referred for medical assessment were studied. All subjects underwent physical examination, anthropometric and dual energy X-ray absorptiometry (DEXA) scan measurements and real-time ultrasonographic (US) examination of the liver. Fasting blood samples were collected for the measurement of liver function, hepatitis status, levels of serum glucose and insulin and lipid profile. Degree of fatty infiltration of the liver was graded according to ultrasonic appearance of liver echotexture, liver-diaphragm differentiation in echo amplitude, hepatic echo penetration and clarity of hepatic blood vessels. RESULTS: All recruited subjects had no history of alcohol abuse and tests for Hepatitis B or C virus were negative. Thorough examination showed all of them to be in general good health without signs of chronic liver disease. Hepatic steatosis identified by defined ultrasonic appearances was diagnosed in 65 subjects (77%); 17 girls and 48 boys. The severity of fatty liver was positively related to anthropometric measurements including BMI, waist and hip circumference, subscapular skinfold thickness; insulin resistance markers [QUICKI and homeostasis model assessment (HOMA)], and hypertriglyceridaemia. Multvariate ordinal regression analysis showed that BMI and raised alanine aminotransferase (ALT) were positively associated with fatty liver. Combination of hepatic steatosis with raised ALT (presumptive NASH) was found in 19 subjects (24%). This group of patients had significantly higher waist hip ratio and conicity index compared to those with isolated hepatic steatosis. Boys with presumed NASH were also found to have significantly higher insulin resistance. CONCLUSION: Nonalcoholic fatty liver disease (NAFLD) was common among our cohort of obese children referred for medical assessment. The prevalence of simple steatosis and presumed NASH was 77 and 24%, respectively. The severity of US steatosis was positively correlated with BMI, raised ALT, insulin resistance and hypertryglyceridaemia. Ultrasonography being noninvasive and readily available could be used for the monitoring of the progression of hepatic steatosis. Further longitudinal studies are required to determine the natural disease progression and the role of insulin resistance and other factors in the pathophysiology of NAFLD.

Adolescent↗
PubMed2004

Computer-assisted detection as a second reader in symptomatic Asian women with palpable breast cancer.

PURPOSE: To determine the potential role of a computer-assisted detection (CAD) algorithm as a second reader for experienced and inexperienced radiologists in mammography reading in Asian women. MATERIAL AND METHODS: Two-view mammograms performed in 124 consecutive patients who presented with palpable breast cancer masses were retrospectively evaluated by two experienced breast radiologists (7 and 10 years' experience). The original reports of the session radiologists with variable experience of reading mammograms (2 to more than 10 years) were also evaluated. The number of suspicious masses and microcalcification clusters detected in each patient by both groups of radiologists were recorded. The radiologists then re-evaluated the films with the CAD system as a second reader. Any improvement in the detectability of breast pathology by either the experienced radiologists and/or by the session radiologists was then assessed. A total of 127 breasts had biopsy-proven carcinoma; 74 breasts had mastectomy performed. All the imaging results were correlated with tru-cut biopsy or mastectomy histology. RESULTS: With CAD-aided interpretation, there were altogether 95 visible masses and 77 suspicious microcalcification clusters in 109 mammographically detectable cancers correlated with histology results. There was a 7.4% (7/95) and 10.4% (8/77) increase in the number of masses and microcalcification clusters detected, respectively, by the experienced radiologists after application of CAD, whereas the increase was 13.7% (13/95) and 27.3% (21/77) for detection of masses and microcalcifications by the session radiologists, respectively. In 9 patients, a secondary focus detected by CAD was confirmed by histology. Three patients had contralateral breast tumors, 1 had a satellite invasive tumor while 5 had ductal carcinoma in situ on the same breast. Based on the biopsies and 74 mastectomies, the true-positive and false-positive detection rate of CAD was 92.6% and 31.8% for detection of carcinomas. The true-positive and false-positive detection rates were 100% and 58.8% for microcalcification clusters. CONCLUSION: The current generation CAD algorithm helped to improve the detection rate of carcinomas, calcifications and multifocality in Asian breasts.

Adult↗
PubMed2004

Dynamic gadolinium-enhanced magnetic resonance urography for assessing drainage in dilated pelvicalyceal systems with moderate renal function: preliminary results and comparison with diuresis renography.

OBJECTIVE: To evaluate the use of dynamic gadolinium diethylenetriaminepenta-acetic acid (DTPA)-enhanced magnetic resonance urography (Gd-MRU) for assessing kidneys with markedly dilated pelvicalyceal systems and impaired function. PATIENTS AND METHODS: Eight children (mean age 30 months, sd 25) were assessed, diagnosed as having gross unilateral hydronephrosis with a mean (sd) anteroposterior renal pelvic diameter of 36 (7) mm and reduced (30-40%) renal function. Dynamic Gd-MRU was performed after the patients were pre-loaded with intravenous fluid and diuretics, and comprised a dynamic T1-weighted sequence after Gd-DTPA (0.1 mmol/kg body weight) was administered, with a time-intensity curve of each kidney produced. Drainage was diagnosed by a clearly declining time-intensity curve and direct visualization of contrast medium within the ureter in several frames. High-grade or complete obstruction was diagnosed when drainage of contrast medium could not be detected. Gd-MRU results were compared with diuresis radionuclide (mercapto-acetyltriglycine, MAG3) renography within the same week. Unobstructive units detected by Gd-MRU were treated conservatively with a close follow-up by ultrasonography and radionuclide studies. RESULTS: Diuresis MAG3 renography showed drainage in three dilated units and poor washout in five; in contrast, Gd-MRU showed drainage in seven dilated systems (three showed poor washout by MAG3), and obstruction in the remaining case. The unobstructed units detected by MRU under conservative treatment thus showed no further deterioration of renal function or progressive hydronephrosis in the subsequent follow-up (mean 18 months, range 15-23). CONCLUSION: These preliminary results suggest that dynamic Gd-MRU is a useful noninvasive imaging method in distinguishing obstructive from unobstructive dilated systems, particularly in patients with hydronephrosis and reduced renal function.

Child↗
PubMed2004

Magnetic resonance cholangiography in children.

Magnetic resonance cholangiography has been shown to be useful in the evaluation of hepatobiliary problems in paediatric patients. Its clinical application in biliary atresia, choledochal cyst, cholelithiasis, bile plug syndrome and liver transplant are illustrated by the following cases.

Adolescent↗
PubMed2004

Sonographic appearance of mucinous carcinoma of the breast.

OBJECTIVE: The aim of this study was to evaluate the sonographic and mammographic features of mucinous carcinoma and to correlate the imaging features with two histologic classifications. MATERIALS AND METHODS: Two radiologists analyzed the mammographic and sonographic features of 33 mucinous carcinomas. Mammographic features according to the Breast Imaging Reporting and Data System (BI-RADS) and sonographic features were recorded and analyzed. The imaging features of the mass were correlated with the nuclear grade and mucin content of these 33 mucinous carcinomas. The incidence of axillary lymph nodes metastasis in different histologic grades and their detection by imaging were also assessed. RESULTS: As many as 21.2% (7/33) of mucinous carcinomas could not be detected mammographically. When they were detected mammographically, more than 92% of the tumors presented as a mass, either oval or lobular. Microlobulations were present in 38.5% of these lesions. The margin of the lesion as seen on mammography can be used to predict the histologic grade. A circumscribed margin was associated with a favorable histologic grade (p = 0.01), whereas an indistinct margin was more commonly associated with the mixed type of lesion (p = 0.05). Sonographically, mixed cystic and solid components, distal enhancement, and microlobulated margins were commonly found in mucinous carcinomas, with an incidence of 37.5%, 43.8%, and 56.3%, respectively. Homogeneity on sonography was associated with the pure type of mucinous carcinoma and hence a better prognosis. Sonography showed a sensitivity of 50%, specificity of 89%, positive predictive value of 60%, negative predictive value of 84%, and accuracy of 79.2% in the detection of axillary lymph node metastasis. CONCLUSION: Both sonographic and mammographic assessments are important in the correct diagnosis of mucinous carcinoma, the prediction of histologic grade, and the prognosis of the tumors.

Adenocarcinoma, Mucinous↗
PubMed2003

Clinical presentations and outcome of severe acute respiratory syndrome in children.

Hong Kong has been severely affected by severe acute respiratory syndrome (SARS). Contact in households and health-care settings is thought to be important for transmission, putting children at particular risk. Most data so far, however, have been for adults. We prospectively followed up the first ten children with SARS managed during the early phase of the epidemic in Hong Kong. All the children had been in close contact with infected adults. Persistent fever, cough, progressive radiographic changes of chest and lymphopenia were noted in all patients. The children were treated with high-dose ribavirin, oral prednisolone, or intravenous methylprednisolone, with no short-term adverse effects. Four teenagers required oxygen therapy and two needed assisted ventilation. None of the younger children required oxygen supplementation. Compared with adults and teenagers, SARS seems to have a less aggressive clinical course in younger children.

Administration, Oral↗
PubMed2003

Imaging findings of paediatric oncology patients presenting with acute neurological symptoms.

Paediatric oncology patients are prone to central nervous system (CNS) complications due to multiple factors including disorders of the blood cell counts (which include neutropenia, thrombocytopenia or hyperleukocytosis), immunosuppression, neurotoxicity of the treatment, CNS dysfunction due to failure of other organ systems, disease progression of the primary malignancy or metastases. Imaging plays an important role in the management of paediatric oncology patients presenting with acute neurological symptoms. This pictorial review is from our institutional experience on imaging children who are under the care of the Child Cancer Centre. The review consists of a spectrum of neurological complications in paediatric oncology patients. The complications can be classified as (1) cerebrovascular complications, (2) treatment-elated complications, (3) opportunistic infections and (4) tumoural involvement of the CNS. Computed tomography (CT) is the initial choice of investigation, which is easily available and helps to exclude major intracranial abnormality such as haemorrhage. If the CT is negative, magnetic resonance imaging (MRI) should be performed, which is more sensitive for detection of CNS lesions.

Adolescent↗
PubMed2003

Imaging in severe acute respiratory syndrome (SARS).

Severe acute respiratory syndrome (SARS) is a highly infectious disease caused by a novel coronavirus, and has become pandemic within a short period of time. Imaging plays an important role in the diagnosis, management and follow-up of patients with SARS. The current status of imaging in SARS is presented in this review.

Adolescent↗
PubMed2003

Pulmonary tumour microembolism clinically mimicking alveolitis.

A 56 year old man with previously unsuspected recurrence of squamous cell carcinoma of the oesophagus presented with dyspnoea. Bronchoscopy and computed tomography suggested bronchopneumonic changes with an infectious cause. He suffered a rapidly deteriorating course and died despite active treatment, including antibiotics and mechanical ventilation. Necropsy revealed a florid pulmonary tumour microembolism mimicking alveolitis. No bronchopneumonia was seen. The emboli arose from loosely attached tumour vegetations in the tricuspid valve. In a patient with known malignancy, tumour microembolism should be considered as an uncommon cause of rapid respiratory failure, refractory to antibiotic treatment.

Carcinoma, Squamous Cell↗