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Biomedical subjects

K T Wong

Publications and source records attributed to K T Wong.

At least 37 records · Page 2Linked to original sources
PubMed2004

Case report: lumbar artery bleeding as a complication of percutaneous nephrostomy in a patient with coagulopathy.

A case of severe lumbar artery bleeding as a complication of percutaneous nephrostomy (PCN) is presented. A 70-year-old man with coagulation disorder (factor VIII deficiency) underwent left PCN because of left hydronephrosis and abnormal renal function. The procedure was complicated by a major haemorrhage from the left first lumbar artery into the left posterior pararenal space. This case illustrates bleeding from the lumbar artery in a patient with coagulation disorder resulting in a fatal outcome. CT can provide the diagnosis, while angiography with embolisation is an effective means to control the bleeding. These examinations should be performed as soon as possible.

Aged↗
PubMed2004

Vascular lesions of parotid gland in adult patients: diagnosis with high-resolution ultrasound and MRI.

Three adult patients with rare vascular lesions in the parotid gland including pseudoaneurysm, arteriovenous fistula and haemangioma are discussed. All patients presented with non-specific unilateral parotid mass. In all cases high-resolution ultrasound and MRI allowed accurate diagnosis and delineation of the extent of lesion. Conventional angiogram was utilized for planning definitive surgical or endovascular treatment.

Adult↗
PubMed2003

Thin-section CT in patients with severe acute respiratory syndrome following hospital discharge: preliminary experience.

PURPOSE: To report the initial experience regarding thin-section computed tomographic (CT) findings in patients with severe acute respiratory syndrome (SARS) who improved clinically after treatment. MATERIALS AND METHODS: Twenty-four patients (10 men, 14 women; mean age, 39 years; age range, 23-70 years) with confirmed SARS underwent follow-up thin-section CT of the thorax. The scans were obtained on average 36.5 days after hospital admission and were analyzed for parenchymal abnormality (ground-glass opacification, consolidation, or interstitial thickening) and evidence of fibrosis (parenchymal band, traction bronchiectasis, irregular interfaces). Patients were assigned to group 1 (with CT evidence of fibrosis) and group 2 (without CT evidence of fibrosis) for analysis. Patient demographics, length of hospital stay, rate of intensive care unit admission, peak lactate dehydrogenase level, pulsed intravenous methylprednisolone therapy, and peak opacification on chest radiographs were compared between the two groups. RESULTS: Parenchymal abnormality was found in 96% (23 of 24) of patients and ranged from residual ground-glass opacification and interstitial thickening in group 2 (nine of 24, 38%) to fibrosis in group 1 (15 of 24, 62%). Patients in group 1 were older (mean age, 45 vs 30.3 years), had a higher rate of intensive care unit admission (27% [four of 15] vs 11% [one of nine]), more requirement for pulsed intravenous methylprednisolone (87%, [13 of 15] vs 67% [six of nine]), higher peak lactate dehydrogenase level (438.9 vs 355.6 U/L), and higher peak opacification on chest radiographs (estimated area, 14% vs 11%) than patients in group 2. CONCLUSION: Pulmonary fibrosis may develop early in patients with SARS who have been discharged after treatment. Patients who are older and have more severe disease during treatment are more likely to develop thin-section CT findings of fibrosis.

Adult↗
PubMed2003

Severe acute respiratory syndrome: radiographic appearances and pattern of progression in 138 patients.

PURPOSE: To retrospectively evaluate the radiographic appearances and pattern of progression of severe acute respiratory syndrome (SARS). MATERIALS AND METHODS: Chest radiographs obtained at clinical presentation and during treatment in 138 patients with confirmed SARS (66 men, 72 women; mean age, 39 years; age range, 20-83 years) were assessed. Radiographic appearances of pulmonary parenchymal abnormality, distribution, and extent of involvement on initial chest radiographs were documented. Recognizable patterns of radiographic progression were determined by comparing the overall mean percentage of lung involvement for each patient on serial radiographs. RESULTS: Initial chest radiographs were abnormal in 108 of 138 (78.3%) patients and showed air-space opacity. Lower lung zone (70 of 108, 64.8%) and right lung (82 of 108, 75.9%) were more commonly involved. In most patients, peripheral lung involvement was more common (81 of 108, 75.0%). Unifocal involvement (59 of 108, 54.6%) was more common than multifocal or bilateral involvement. No cavitation, lymphadenopathy, or pleural effusion was demonstrated. Four patterns of radiographic progression were recognized: type 1 (initial radiographic deterioration to peak level followed by radiographic improvement) in 97 of 138 patients (70.3%), type 2 (fluctuating radiographic changes) in 24 patients (17.4%), type 3 (static radiographic appearance) in 10 patients (7.3%), and type 4 (progressive radiographic deterioration) in seven patients (5.1%). Initial focal air-space opacity in 44 of 59 patients (74.6%) progressed to unilateral multifocal or bilateral involvement during treatment. CONCLUSION: Predominant peripheral location; common progression pattern from unilateral focal air-space opacity to unilateral multifocal or bilateral involvement during treatment; and lack of cavitation, lymphadenopathy, and pleural effusion are the more distinctive radiographic findings of SARS.

Adult↗
PubMed2003

Thin-section CT of severe acute respiratory syndrome: evaluation of 73 patients exposed to or with the disease.

PURPOSE: To retrospectively analyze the thin-section computed tomographic (CT) features in patients with severe acute respiratory syndrome (SARS) at the authors' institution. MATERIALS AND METHODS: From March 11, 2003, to April 2, 2003, 74 patients with symptoms and signs suggestive of SARS underwent CT of the thorax; all underwent thin-section CT except for one patient who underwent conventional CT. Group 1 (n = 23) patients had symptoms of SARS in keeping with criteria from the Centers for Disease Control and Prevention and a positive chest radiograph. Group 2 (n = 17) patients had a high clinical suspicion of SARS but a normal radiograph. Group 3 (n = 34) patients had minor symptoms and a normal chest radiograph. The thin-section CT images were analyzed for ground-glass opacification or consolidation, lesion size in each lung segment, peripheral or central location, interstitial thickening, and other abnormalities. RESULTS: Thin-section CT scans were abnormal only for patients in groups 1 and 2. The patient with only conventional CT scans was in group 3; scans for group 3 patients were normal. Affected segments were predominantly in the lower lobes (91 of 149 affected segments). Common findings included ground-glass opacification, sometimes with consolidation, and interlobular septal and intralobular interstitial thickening. The size of each lesion and the total number of segments involved were smaller in group 2 patients. A majority of patients in group 1 (14 of 23) had mixed central and peripheral lesions. In group 2, however, peripheral lesions were more common (10 of 17). In both groups, a purely central lesion was uncommon (one of 23 in group 1 and two of 17 in group 2). CONCLUSION: Common thin-section CT features of SARS are ground-glass opacification and lower lobe and peripheral distribution.

Adolescent↗
PubMed2003

Computed tomography of common congenital lesions of the temporal bone.

This pictorial review describes the application of high-resolution computed tomography to the investigation and pre-operative work-up of the common lesions of congenital hearing loss, including congenital aural dysplasia, various congenital ossicular anomalies, inner ear dysmorphology, large vestibular aqueduct syndrome, and congenital absence of cochlear nerve and labyrinthitis ossificans from previous infection. The aim is to help radiologists to provide a more accurate diagnosis of underlying aetiology and assist in surgical planning.

Cochlea↗
PubMed2003

Computed tomography imaging of the temporal bone--normal anatomy.

This review describes the fundamental anatomical structures of the temporal bone as depicted on high-resolution computed tomography, and the clinical significance of these structures. It is not an encyclopaedic atlas, but provides the junior radiology/otorhinolaryngology resident with sufficient knowledge for interpretation of most of the imaging studies encountered in daily clinical practice.

Ear Canal↗
PubMed2003

Accuracy of high-resolution sonography compared with magnetic resonance imaging in the diagnosis of head and neck venous vascular malformations.

AIMS: To evaluate whether modern ultrasound examination helps to establish the diagnosis of head and neck venous vascular malformations (VVMs) and whether it can delineate their full extent. MATERIALS AND METHODS: Sonographic appearances of 30 head and neck VVMs were assessed for: location, extent, internal architecture, presence of flow and phleboliths. These results were compared with the magnetic resonance imaging (MRI) of the same patients. RESULTS: The lesions showed well-defined margins (22 of 30, 73%), heterogeneous (30 of 30, 100%) and hypoechoic echo pattern (27 of 30, 90%), with sinusoidal spaces (28 of 30, 93%) and phleboliths (24 of 30, 80%) on grey-scale imaging, and flow signal on Doppler (28 of 30, 93%). For delineating the extent, ultrasound was comparable with MRI in 53% (16 of 30) and inferior to MRI in 47% (14 of 30). Ultrasound did not detect deeper extent, intra-osseous involvement and other clinically occult VVMs. CONCLUSION: Ultrasound with high-resolution transducers can confidently suggest the diagnosis of head and neck VVMs in up to 90% of cases, and delineate the full extent of some superficial lesions. The major disadvantage is its inability to evaluate intra-osseous involvement and the entire extent of large, deep-seated 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

Elucidation of Nipah virus morphogenesis and replication using ultrastructural and molecular approaches.

Nipah virus, which was first recognized during an outbreak of encephalitis with high mortality in Peninsular Malaysia during 1998-1999, is most closely related to Hendra virus, another emergent paramyxovirus first recognized in Australia in 1994. We have studied the morphologic features of Nipah virus in infected Vero E6 cells and human brain by using standard and immunogold electron microscopy and ultrastructural in situ hybridization. Nipah virions are enveloped particles composed of a tangle of filamentous nucleocapsids and measured as large as 1900 nm in diameter. The nucleocapsids measured up to 1.67 microm in length and had the herringbone structure characteristic for paramyxoviruses. Cellular infection was associated with multinucleation, intracytoplasmic nucleocapsid inclusions (NCIs), and long cytoplasmic tubules. Previously undescribed for other members of the family Paramyxoviridae, infected cells also contained an inclusion formed of reticular structures. Ultrastructural ISH studies suggest these inclusions play an important role in the transcription process.

Animals↗
PubMed2003

Kuttner tumour (chronic sclerosing sialadenitis) of the submandibular gland: sonographic appearances.

Patients with Kuttner tumours present with clinical features simulating a submandibular tumour. This article aims to familiarise sonologists with the sonographic appearances of these tumours, to help in their differentiation from other salivary lesions. In 13 patients with histologically or cytologically proven Kuttner tumours, the features evaluated on sonography included: shape and border of the gland, internal architecture, duct dilatation, presence/absence of calculi and presence and distribution of vascularity. There was diffuse involvement of the submandibular glands in 11 patients and focal involvement in 2. The majority (9 of 11) of the patients with diffuse involvement showed sonographic appearances simulating a "cirrhotic" liver; 2 showed diffuse heterogeneous involvement with duct dilatation and calculus. Doppler showed prominent intraglandular vessels, with no evidence of displacement. Focal lesions (2 of 11) were seen as hypoechoic, heterogeneous "masses," with a radial branching vascular pattern within, on Doppler. In conclusion, sonographic features may help in identifying Kuttner tumours of the submandibular glands.

Adult↗
PubMed2003

[Severe acute respiratory syndrome (SARS)].

The severe acute respiratory syndrome (SARS) is a highly infectious respiratory disease, to the best of our knowledge caused by a hitherto unknown corona virus. The virus has spread from South East Asia to many countries of the world. Three case reports of patients from the Prince of Wales Hospital of The Chinese University of Hong Kong demonstrate typical clinical courses. Fever, cough, in most cases non-productive, myalgia, chills, and rigor are the leading symptoms. Leucopenia and thrombocytopenia are the most prominent laboratory parameters, increased values for lactatedehydrogenase (LDH) reflect a more severe clinical course. Advanced age and coexisting conditions seem to influence the prognosis unfavourably. The chest roentgenogram may be normal initially but at a later stage progressive consolidations in the majority of peripheral parts of the lung are observed, which cannot be differentiated from pneumonias of other origin. Even young patients can enter a stage of respiratory compromise rather fast. A therapy against the cause of the disease is not known. Empirical therapy with ribavirin in combination with high dose corticosteroids have proved successful. The disease may progress into respiratory failure comparable with an acute respiratory distress syndrome (ARDS). Mortality is around five to ten per cent. Stringent hygiene and quarantine measures are mandatory to prevent the further spread of this threatening disease.

Adult↗
PubMed2003

Paraffinoma in anterior abdominal wall mimicking liposarcoma.

Paraffinoma of breast is a recognized complication of paraffin injection for breast augmentation. Liquid paraffin can extend along fascial planes to involve adjacent tissues. A rare case of paraffinoma in anterior abdominal wall, which was misdiagnosed as a soft tissue liposarcoma before surgical excision, is reported. It was heterogeneous with marked posterior acoustic shadowing and small peripheral cysts on ultrasound. On MRI, it had ill-defined margins and was heterogeneous in signal intensity. Small round components which were hypointense on all sequences were demonstrated. There is significant overlapping of imaging features between paraffinoma and soft tissue liposarcoma. Histological differentiation from well-differentiated liposarcoma may also be difficult. A detailed clinical history of previous paraffin injection for breast augmentation is very important for correct interpretation of imaging and histopathological findings.

Abdominal Wall↗
PubMed2003

Nipah encephalitis outbreak in Malaysia.

INTRODUCTION: Between September 1998 and June 1999, there was a severe outbreak of viral encephalitis among the pig farm workers in Malaysia. METHODS: This is a review of the published literature related to the outbreak with the focus on human diseases. RESULTS: The encephalitis was caused by a newly discovered paramyxovirus related to Hendra virus, later named Nipah virus. There were 265 patients with acute encephalitis. The disease is thought to spread from pig to man through close contact. The risk of human-to-human spread is thought to below. The disease affected mainly adult Chinese males, half of whom had affected family members. The disease presented mainly as acute encephalitis with a short incubation period of less than two weeks, with the main symptoms of fever, headache, and giddiness followed by coma. Distinctive clinical signs include segmental myoclonus, areflexia and hypotonia, hypertension, and tachycardia. Initial cerebrospinal fluid was abnormal in 75% of patients. Serology was helpful in confirming the diagnosis. Magnetic resonance imaging showed distinctive changes of multiple, discrete, and small high signal lesions, best seen with fluid-attenuated inversion recovery (FLAIR) sequences. Mortality was high at 40% and death was probably due to severe brainstem involvement. The main necropsy finding in acute encephalitis was that of disseminated microinfarction associated with vasculitis and direct neuronal involvement. Ribavirin was able to reduce the mortality by 36%. Relapse encephalitis was seen in 7.5% of those who recovered from acute encephalitis, and late-onset encephalitis in 3.4% of those with initial non-encephalitic or asymptomatic diseases. The mean interval between initial illness and the onset of the complication was 8.4 months. The relapse and late-onset encephalitis which manifested as focal encephalitis arose from recurrent infection. CONCLUSION: Nipah virus, a recently discovered paramyxovirus, causes a unique encephalitis with high mortality as well as relapse and late-onset encephalitis. The infection is mainly spread from pigs to man.

Agriculture↗
PubMed2002

Nipah virus infection, an emerging paramyxoviral zoonosis.

The Nipah virus outbreak represented one of several bat-derived paramyxoviruses that has emerged during the last decade to cause severe human and animal disease. The pathogenesis of Nipah infection is associated with its ability to infect blood vessels and extravascular parenchyma in many organs, particularly in the central nervous system. The clinical manifestations of acute Nipah infection range from fever and mild headache to a severe acute encephalitic syndrome in which there is a high mortality. Much remains to be understood about this new disease, including its intriguing ability to cause relapsing encephalitis in some survivors. This review provides an overview of the Nipah outbreak, focussing on what is presently known about it as an infectious disease, including the clinical aspects, pathology and pathogenesis.

Animals↗
PubMed2002

Syncope in children and adolescents of Hong Kong.

OBJECTIVES: Syncope occurs commonly in children and adolescents. The objectives of the present study were to quantify this occurrence locally and to examine the profiles of subjects experiencing syncope. METHODOLOGY: A self-administered questionnaire was filled out by students between 6 and 17 years of age from a selected school in January 1999. RESULTS: Out of 2574 completed questionnaires, a total of 121 subjects reported having had at least one previous episode of syncope, including 9.0% of the 15-17 years age group. The overall incidence of a first syncope in the preceding 12 months was 1.7% and was highest (3.3%) in the 15-17 years age group. No significant difference in incidence was noted between sexes. Among those who experienced syncope, 32.2% had sought medical advice and 9.1% had been admitted to hospital; 57.9% became worried, while 37.2% reported restriction of daily activities because of syncope. CONCLUSION: Syncope is a common event in children and adolescents in Hong Kong. It can cause a considerable degree of anxiety and activity restriction. The impact on medical services due to syncope in Hong Kong has been substantial.

Adolescent↗