PubMed Health⌕ Search

Biomedical subjects

T S Chee

Publications and source records attributed to T S Chee.

16 recordsLinked to original sources
PubMed1998

Overview of imaging in rheumatologic diseases.

The role of radiology in rheumatologic diseases has for many years been confined to conventional radiography alone. The advances in medicine placed great demands on earlier and more accurate evaluation of these diseases. Conventional radiographs have been used as diagnostic aids and radiographic features and measurements are well established. However, the newer technologies, such as ultrasound, computed tomography and magnetic resonance imaging (MRI) have recently influenced accuracy of diagnosis and allowed for earlier detection and a more comprehensive evaluation of the results of therapy. One leading example is the significant role MRI plays in the early detection of avascular necrosis, especially of the hips. The clinical benefits of the newer modalities in radiology are being increasingly recognised and its full potential realised by both rheumatologists and radiologists.

Diagnostic Imaging↗
PubMed1997

MRI of the fornix and mamillary body in temporal lobe epilepsy.

We performed MRI on 27 patients with clinically proven temporal lobe epilepsy (TLE), all with prior EEG lateralisation, and 10 volunteers, studied to evaluate disparity in size arising from biological variation (group 1). Three-dimensional spoiled GRASS (3DSPGR) sequences provided 2-mm contiguous sections of the limbic system, enabling assessment of the hippocampus (HC), fornix (FN) and mamillary body (MB). Measurements of FN and MB width were made from a workstation. Any percentage difference in size was computed. In 19 cases there was unilateral abnormality in the HC (group 2); in 18 and 19 cases respectively there was a smaller FN and MB on the same side as the abnormal HC. This percentage difference in size was significantly greater than that in group 1 in the FN and MB in 17 and 17 cases respectively. Comparison of percentage difference computations for FN and MB between groups 1 and 2 showed high statistical significance (P < 0.0002). In 5 patients with clinical TLE the HC was normal on MRI (group 3). Unequal FN and MB sizes were found in 4, significant in 2. Comparison of percentage difference computations for FN and MB showed statistical significance (P < 0.0005 and P < 0.0003 respectively). There was no case of discordance between the sides of hippocampal abnormality and the smaller FN or MB or between the sides of smaller FN and MB. The strong concordance between the changes in the HC and those in the FN and MB suggests that this combination will play an important role in the assessment of TLE and limbic system abnormality.

Adolescent↗
PubMed1997

The lumbosacral lucent cleft.

BACKGROUND: The lumbosacral lucent cleft was first described in association with traumatic injuries to the neck. However, we have observed this sign to be present in patients with no precursor of trauma, and we reviewed the incidence of lucent cleft sign in our local population and any characteristic features of the lucent cleft. METHODS: Four-hundred and thirty lumbosacral spine radiographs were examined prospectively over an 8-month period, with correlation with clinical findings. Follow-up radiographs were obtained at 1, 3 and 6 months for patients with the lucent cleft sign. FINDINGS: Nineteen patients (4.4%) were found to have lucent clefts in their lumbosacral spine X-rays. No significant change in the number and features to the lucent clefts was noted even when the symptoms had resolved after 6 months. All the lucent clefts were linear, horizontally oriented and located at the anterior edge of the adjacent vertebral body. CONCLUSION: The lucent cleft sign in the spine, which has so far been described in association with has spinal trauma may be completely innocuous in patients with little or no symptoms.

Adolescent↗
PubMed1995

Hypertension in disguise--a trap for the unwary.

A 36-year-old asymptomatic Chinese male with polycystic kidney disease (PKD) developed hypertension 1 year after the diagnosis of PKD. The patient was treated initially as for hypertension associated with PKD. However, over a 6-year period his hypertension became progressively difficult to control and he developed severe symptomatic hypokalemia. Subsequent investigations confirmed the presence of primary hyperaldosteronism. The initial computed tomographic scans of the adrenals did not reveal any definite adenomas. The patient subsequently underwent bilateral adrenal venous sampling, which suggested a left-sided source of aldosterone excess. A repeat computed tomography of the adrenals with fine cuts revealed a 6-mm diameter adenoma of the left adrenal gland. He underwent an uncomplicated left adrenalectomy. All antihypertensive and potassium supplements were stopped on the 5th postoperative day. Two and half years after the adrenalectomy he remains normotensive and normokalaemic without any medication. The case illustrates the importance of measuring serum potassium before initiation of any therapy and the need to consider secondary causes even if a primary association is known. It also reinforces the fact that when hypertension becomes difficult to control, a secondary cause has to be searched actively. The association between primary aldosteronism and renal cysts has been highlighted only recently. The association of polycystic kidneys and primary aldosteronism has been reported in the literature only once previously.

Adenoma↗
PubMed1995

Neuronal migration disorder presenting with epilepsy: a report of five illustrative cases.

Neuronal migration disorders are an uncommon but well-recognised cause of medically intractable epilepsy. The increasing availability of magnetic resonance imaging of the brain has made it possible to diagnose this condition ante-mortem. There are several types of migration disorders, each with different radiological and clinical features. A case each of focal cortical dysplasia, focal subcortical heterotopia, double cortex syndrome, periventricular nodular heterotopia and closed lip schizencephaly is presented to highlight the distinctive features of each entity.

Adult↗
PubMed1995

Percutaneous balloon valvuloplasty in mitral restenosis after previous surgical commissurotomy.

OBJECTIVES: The aim of this study was to determine the safety profile, mitral valve outcome and follow-up functional status after percutaneous balloon mitral valvuloplasty (PBMV) in patients with mitral restenosis post-surgical commissurotomy. METHODS: Sixteen patients with symptomatic mitral restenosis after previous surgical commissurotomy underwent valvuloplasty using the Inoue balloon stepwise dilatation method. Echocardiography was performed before and after the procedure to evaluate the mitral valve area. RESULTS: All procedures were successfully completed without cardiac perforation, thromboembolism, resultant severe mitral regurgitation or death. The mitral valve area improved from 0.9 +/- 0.2 to 1.6 +/- 0.3 (p = 0.0001), accompanied by a significant immediate reduction in the left atrial pressure and transmitral gradient. Compared with PBMV in patients without past mitral surgery, patients with mitral restenosis undergoing PBMV experienced less valve area improvement but the difference was not significant (p = 0.137). Optimal valve enlargement resulting in mild mitral stenosis was achieved in 12 of the 16 patients. Midterm symptomatic benefit was observed in almost all patients. CONCLUSIONS: In view of the excellent success rate, low complication risk, the optimal haemodynamic results and favourable functional outcome afforded by mitral balloon valvuloplasty in patients with mitral restenosis after prior surgical commissurotomy, it is logical that balloon mitral valvuloplasty, where available, should be the initial treatment modality in this group of patients with suitable valve morphology before considering repeat mitral surgery.

Adult↗
PubMed1995

Clinical utility, safety, acceptability and complications of transoesophageal echocardiography (TEE) in 901 patients.

Transoesophageal echocardiography (TEE) has earned an important role in the evaluation of patients with cardiovascular diseases. We report our TEE experience in 901 patients who had suboptimal transthoracic echocardiographic studies performed between September 1989 and June 1993. The patient-population consisted of 459 females and 442 males, with an ethnic distribution of Chinese 76.5%, Malays 12.7%, Indians 8.5% and Others 2.3%. The mean age was 48 years. The main indications for TEE were: cardiac source of embolism (27.5%); native valve pathology (19.1%); atrial septal abnormality (9.7%); infective endocarditis (8.3%); intracardiac masses (7.0%); prosthetic valve dysfunction (6.3%); congenital heart diseases (4.6%); aortic diseases (3.4%) and miscellaneous (14.1%). The majority of the studies were done on in- and out-patients, with only 1.2% performed in the intensive care area and 1% intraoperatively. 82.6% of TEE intubation were accomplished within one minute and most of the TEE studies were completed within twenty minutes. There were ten failures (1.2%). Major complications occurred in 5 patients (0.6%) but there was no mortality. 90.5% of the studies were considered by the operators as additionally-informative or useful for clinical decision making. In a subgroup analysis, 90.6% of the patients who had undergone TEE indicated their willingness for repeat studies if required and TEE was able to increase the sensitivity of detecting a potential cardioembolic source from 10.3% to 29.5%. In conclusion, with increasing experience, TEE can be performed expeditiously and safely, with good acceptability by our local population. TEE provides useful or additional information that supplements standard transthoracic echocardiography in a wide-ranging spectrum of cardiac conditions.

Adolescent↗
PubMed1994

Massive acute pulmonary embolism in protein S deficiency--a case report.

A young man with a history of deep vein thrombosis and pulmonary embolism 11 years ago presented again with acute pulmonary embolism and was treated initially with intravenous heparin at our institution. Five days later he had another massive bout of pulmonary embolism causing hypotension. Pulmonary angiography confirmed the presence of thrombi in both pulmonary arteries, with complete obstruction of the left pulmonary artery. He was treated successfully by emergency pulmonary embolectomy. Blood investigations later confirmed the diagnosis of protein S deficiency and he was started on warfarin therapy for life. Massive pulmonary embolism should be treated aggressively. Thrombolytic therapy accelerates clot lysis, reduces pulmonary pressures, restores pulmonary capillary volume and reverses right heart failure faster than heparin alone. There is also a trend towards decreased mortality with thrombolysis. In the presence of shock, the patient should be resuscitated and if facilities for emergency embolectomy are available, surgery is a viable alternative to thrombolysis, especially if the clot burden is massive. In young patients with recurrent venous thromboembolism in the absence of obvious predisposing factors, it is important to exclude inherited plasma protein deficiencies of protein S, protein C, antithrombin III, plasminogen and fibrinogen.

Acute Disease↗
PubMed1994

Echocardiographic detection of mobile right atrial thrombus.

Mobile right atrial thrombus is a rare echocardiographic diagnosis with important implications on further management. We report a case of 50-year-old woman with deep vein thrombosis of her left lower limb, who was found to have a large mobile serpiginous right atrial thrombus on both two-dimensional echocardiography (2DE) and transoesophageal echocardiography (TEE). She developed acute pulmonary embolism within thirty-six hours of diagnosis and subsequently underwent successful pulmonary embolectomy. This case demonstrates the usefulness of echocardiography as a non-invasive tool in the investigation of suspected pulmonary thromboembolism. The detection of right atrial thrombus mandates serious consideration for prompt surgical action.

Echocardiography↗
PubMed1993

Percutaneous transseptal balloon mitral valvotomy: initial experience in Singapore.

Between June 1990 and August 1991, 28 percutaneous transseptal balloon mitral valvotomy procedures were attempted in 27 patients (23 women and 4 men; mean age 39.8 +/- 9.3 years) with severe mitral stenosis. Successful mitral valvotomy was achieved in 25 patients (primary success rate of 92%). Mitral valve area increased from 0.82 +/- 0.17 cm2 to 1.53 +/- 0.48 cm2 (p < 0.001) and the mean mitral valve gradient decreased from 13.4 +/- 7.4 to 6.0 +/- 5.4 mmHg (p < 0.05). There were no deaths, one patient had cardiac tamponade after transseptal puncture and required emergency pericardiocentesis with successful percutaneous balloon valvotomy 6 months later. One patient had an unsuccessful valvotomy because the mitral valve could not be crossed and another patient had an inadequate dilatation. Our initial experience in percutaneous transseptal mitral valvotomy confirms the safety and efficacy of this new technique for the treatment of rheumatic mitral stenosis.

Adult↗
PubMed1992

Lipid screening in a volunteer population in Singapore.

Coronary risk profile screening was performed in 1065 volunteers during the National Heart Week 1988 as part of the National Heart Association's campaign against the increasing incidence of ischaemic heart disease. Of particular importance was the use of a desktop analyser for lipid screening of total cholesterol and high density lipoprotein (HDL) cholesterol. It was found that the mean serum cholesterol was 211 +/- 39.5 mg/dl, with 62% of the participants having a total cholesterol greater than 200 mg/dl and 23.1% having a total cholesterol greater than 240 mg/dl. For HDL cholesterol, the mean was 48.4 +/- 17 mg/dl, with 18.7% of the participants having a low HDL cholesterol of less than 35 mg/dl. The male Indians had a significantly lower HDL cholesterol compared to male Malays. Three or more risk factors for coronary artery disease was present in 21.7% of Chinese, 41.2% of Malays and 50% of Indians. We conclude therefore that a proportion of this volunteer population, the majority of which have no overt heart disease, is at risk from coronary artery disease from an elevated cholesterol or low HDL cholesterol level. A follow-up of 90 participants who were initially detected to have an elevated cholesterol in 1986, however, showed that only 54.4% still had an elevated cholesterol of greater than 240 mg/dl, thus suggesting that early detection may help to reduce this risk.

Age Factors↗
PubMed1991

The anatomy of the Fossa of Rosenmuller--its possible influence on the detection of occult nasopharyngeal carcinoma.

The Fossa of Rosenmuller (FOR) is a well established site of origin of nasopharyngeal carcinoma (NPC). Detection of early NPC requires a sound knowledge of the anatomy of the FOR. The authors study the anatomy of the FOR with the aid of CT Scan and discuss the possible influence of the anatomy of the FOR on the detection of occult NPC. This paper reveals that there are cases of postnasal space which cannot be fully inspected clinically due to the peculiar anatomy of the FOR.

Adolescent↗
PubMed1990

Clinical impact of echo-Doppler in the management of heart disease.

The management of patients with cardiovascular disease requires a comprehensive evaluation of both morphological and pathophysiological abnormalities associated with the disease process. To this end, a diagnostic technique that is noninvasive, painless, biologically safe, readily repeatable, economical and highly accurate would be ideal. The echo-Doppler modality satisfies these criteria and in so doing has emerged the diagnostic procedure of choice in many instances. While echocardiography supplies detailed anatomical information on cardiovascular structures, the Doppler mode define the associated haemodynamic profiles. Used in complement, they provide a complete pathophysiological picture in the majority of congenital and acquired cardiac diseases, aiding both diagnostic and therapeutic management decisions.

Blood Flow Velocity↗
PubMed1990

Transoesophageal echocardiography--an overview.

The introduction of transoesophageal echocardiography has provided another acoustic window to the heart and mediastinum. The unique relationship of the esophagus to the heart and thoracic aorta has made transesophageal echocardiography ideal for imaging and assessment of the mitral valve particularly mitral prosthesis, atrial appendages, atrial septum, cardiac masses, aortic valve and thoracic aorta. It is a safe procedure and can be easily performed on patients as an outpatient procedure, on critically ill patients as well as for intraoperative monitoring of left ventricular function and air embolism and intraoperation assessment of cardiovascular surgical procedures.

Aortic Diseases↗
PubMed1990

Coronary risk profile screening during National Heart Week--1986.

Coronary risk profile screening was performed in 1422 volunteer subjects during National Heart Week 1986. A great proportion (55%) of this study group had blood cholesterol above 200 mg/dl; 10% of the subjects were smokers. This study documents the coronary risk profile of 1422 subjects whose biodata provide a baseline for future follow up of the possible changes in any of the various risk factors. This study identifies modifiable risk factors, high blood cholesterol and smoking which should be the target of public education in the efforts to reduce coronary diseases in Singapore.

Adult↗