Background Isotope proctograms (IP) or colonic transit studies (CTS) are usually performed separa... more Background Isotope proctograms (IP) or colonic transit studies (CTS) are usually performed separately for evacuatory and motility disorders of the lower GI tract. Aim To evaluate any associated colonic motility disorders in patients with evacuatory difficulties. Methods In a retrospective review, 86 patients with evacuatory difficulties were referred for IP over a 3 year period. Sixteen of these patients, who also had CTS, were reviewed for this study. Results All 16 patients had abnormalities in both studies. In 16 IP studies, rectoceles were identified in 11 patients, 3 patients were unable to defaecate but clinically had rectoceles and 2 patients had prior repair of rectoceles. All 16 CTS were abnormal; 8 patients had rightsided delay and 6 had generalized delay, indicating slow colonic transit. Two further patients had left-sided delay, indicating nearly normal colonic transit but impaired rectal function. Mean rectocele sizes were 2.9 and 3.6 cm respectively for right sided and generalized delay groups. Conclusions There is a close association between lower GI tract evacuatory and motility disorders and we recommend performing both IP and CTS in patients referred for investigation of evacuatory difficulties. 3.11 (1.49) 2.7-4.0 < 0.001
Experimental and Clinical Endocrinology & Diabetes, 2008
Radioiodine (I-131) is a useful therapeutic modality of hyperthyroidism when medical therapy fail... more Radioiodine (I-131) is a useful therapeutic modality of hyperthyroidism when medical therapy fails. Traditionally, the nuclear physicians undertake the prescription of I-131 therapy. However, endocrinologists are increasingly being recognized for their competence in prescribing individualized doses of I-131 for the treatment of various thyroid disorders. In this pilot prospective study, we collaborated with our nuclear medicine colleagues to determine the outcomes of 80 patients with hyperthyroidism who underwent I-131 ablation as prescribed by the endocrinologist. Doses administered were based primarily on thyroid volume with adjustments contingent on adverse factors, and fixed assumptions on target absorbed dose (R) and uptake (U) were used. Seventy-three had Graves&#39; disease (GD) and seven had toxic nodular goitre (TNG) or toxic adenomas (AFTN). Therapeutic success was defined as achievement of hypothyroidism or euthyroidism. 95.9 percent (70 of 73) of GD patients and 85.7 percent (6 of 7) of those with TNG/AFTN achieved successful outcomes after a single dose of endocrinologist-directed I-131 therapy. More than 50 percent of patients became hypothyroid by three months and about two-thirds became hypothyroid by six months post I-131 therapy. Our results indicate that the success rate of endocrinologist-directed I-131 therapy exceeds 95 percent with a single dose and compares favourably with nuclear physician-directed therapy outcomes.
A small 6-cm colonic J-pouch improves stool frequency and continence, without stool evacuation pr... more A small 6-cm colonic J-pouch improves stool frequency and continence, without stool evacuation problems. However, the reservoir function is not improved on physiologic studies. Hence, a scintigraphy technique was devised to study the transit of solid and liquid colonic contents in these patients. Patients were randomly assigned to straight or colonic J-pouch anal anastomoses after ultralow anterior resection. At 1 year after surgery, they were studied by bowel questionnaire, anorectal manometry, and technetium TC 99m tin-colloid liquid test meal/I-131 microcapsule scintigraphy. In the latter, technetium TC 99m tin-colloid was ingested orally to image the colonic liquids. I-131 microcapsules taken simultaneously imaged the solid stools. After ingestion of the radioisotopes, imaging was performed at intervals of 7 to 8, 24, and 56 hours later. Two independent observers noted the presence of technetium TC 99m tin-colloid liquid and I-131 microcapsules in various areas of interest drawn over the colon. There were six patients (5 males, mean age, 61.5 (SE mean, 1.9) years) in the straight, and six patients (5 males, mean age, 63.2 (4.5) years) in the colonic J-pouch group. Stool frequency was more in the straight group (4.8 (0.4) vs. 3 (0.2) stools/day; P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;.001). Continence, evacuation problems, and anorectal physiologic findings were not different. Technetium TC 99m tin-colloid (imaging liquids) transited significantly faster than I-131 microcapsules (imaging solids), at various areas of interest in the colon. In the colonic J-pouch patients, technetium TC 99m tin-colloid liquid was retained significantly longer in the descending colon at 24 hours (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;.05). Stool frequency was higher when technetium TC 99m tin-colloid was not retained in the descending colon at 56 hours (3.3 (0.5) vs. 4.3 (0.4) stools/day) but this did not reach statistical significance. There were no significant differences in the distribution of the ingested I-131 microcapsules between colonic J-pouch and straight groups. Reduced stool frequency after colonic J-pouch may be related to factors causing better retention of liquid stools in the distal colon. No difference in solid stool transit could possibly account for minimal evacuation problems in small pouches.
Http Dx Doi Org 10 1089 Thy 2006 16 461, Jun 1, 2006
Thyroid cancer is among the 10 most common malignancies in populations in the Asia Pacific region... more Thyroid cancer is among the 10 most common malignancies in populations in the Asia Pacific region, where access to various relevant health care resources varies widely. An expert consensus conference was held to define regional patterns of practice and guidelines for optimal management of well-differentiated epithelial thyroid carcinomas. Practice patterns vary from country to country, as would be anticipated form their variety of ethnic and racial populations, health care systems, economies, and cultures. Thyroid cancer care is provided by a number of medical and surgical specialists, usually including endocrinologists. The thyroid surgical skills, experience, and outcomes vary widely in the region. Radioiodine is available, to a greater or lesser extent, is almost all countries. Laboratory services for thyroid function monitoring are universally accessible; thyroglobulin assays are available in most countries. Recombinant thyrotropin is approved for use in only two countries, but can be accessed in some others on a &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;named patient&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; compassionate need basis. Access to advanced imaging, for exampke, positron emission tomography (PET) scanning, is limited to a few countries. In light of these realities, appropriate strategies for initial treatment and postoperative monitoring of patients with thyroid cancer have been defined, and these are presented and discussed.
atients with well-differentiated thyroid cancer are fol lowed up after thyroidectomy by serial se... more atients with well-differentiated thyroid cancer are fol lowed up after thyroidectomy by serial serum thyroglobulin (Tg) estimation and ‘@‘I whole-body scanning. The use of 1311 requires the suspension of thyroxine (L-3,5,3',5'
Annals of the Academy of Medicine, Singapore, 2001
Medullary thyroid carcinoma (MTC) is a rare thyroid malignancy but accounts for a significant mor... more Medullary thyroid carcinoma (MTC) is a rare thyroid malignancy but accounts for a significant mortality. We present 2 cases of MTC and review the literature regarding its management and genetic screening. Patient 1 presented after a routine health screening and subsequently was found to have a germline mutation for MEN 2A. Patient 2 presented with sweating irritability and a thyroid mass which illustrates the progressive relentless nature of the disease and highlights current imaging practice. Both patients underwent extensive surgery and received postoperatively ablative dose of radioactive iodine. Patient 2 also had a large dose I-131 MIBG therapy and further surgery. In Patient 1, postoperative calcitonins remained elevated indicating residual disease. Patient 2 underwent further radioguided surgery; however, his postoperative calcitonins remained elevated. MTC can be relentless. Routine genetic screening of all patients with MTC, Tc-99m pentavalent (V) DMSA imaging, near total t...
atients with well-differentiated thyroid cancer are fol lowed up after thyroidectomy by serial se... more atients with well-differentiated thyroid cancer are fol lowed up after thyroidectomy by serial serum thyroglobulin (Tg) estimation and ‘@‘I whole-body scanning. The use of 1311 requires the suspension of thyroxine (L-3,5,3',5'
Patients with acute coronary syndrome (ACS) often present atypically. In a randomized controlled ... more Patients with acute coronary syndrome (ACS) often present atypically. In a randomized controlled trial, we studied whether adding stress myocardial perfusion imaging (SMPI) to an evaluation strategy for emergency department (ED) patients presenting with chest pain more effectively identifies patients with ACS. Participants were randomized to standard ED chest pain protocol (clinical assessment) or standard protocol supplemented with SMPI results. During 6 hours of electrocardiogram (ECG) monitoring and serial cardiac markers (creatine kinase-MB isoenzyme, troponin), participants developing ST segment changes or elevated cardiac markers were admitted. Those with a negative observation period underwent SMPI (N = 1,004) or clinical assessment (N = 504) based on randomization, and admitted if their SMPI scan was abnormal or senior clinicians found a high or intermediate risk for ACS. SMPI participants had a significantly lower admission rate than clinical assessment participants (10.16% vs 18.45%), with no significant between-group differences in risk of cardiac events (CEs) after 30 days (0.40% vs 0.79%) or 1 year (0.70% vs 0.99%). When added to a standard triage strategy incorporating clinical evaluation, serial ECGs, and cardiac markers, SMPI improved clinical decision making for chest pain patients, significantly reducing the need for hospitalization without an increase in adverse CE rates at 30 days or 1 year.
The incidence of thyroid cancer is low, but when it occurs, it is mainly of the papillary histopa... more The incidence of thyroid cancer is low, but when it occurs, it is mainly of the papillary histopathological type. Although PET/CT has a limited role in the diagnosis, it plays a significant role in the overall post-surgery management of a patient with thyroid cancer. This follow-up role is important, especially in patients with elevated serum thyroglobulin, but negative radioiodine whole body scans. There is increasing evidence that PET/CT should be a part of routine care in the Tg positive Radioiodine scan negative patient.
Soluble radioaerosols such as technetium-99m diethylene triamine pentacetate (DTPA) permit simple... more Soluble radioaerosols such as technetium-99m diethylene triamine pentacetate (DTPA) permit simple quantitative studies of alveolar-capillary permeability to be performed, since the submicronic aerosols are deposited mainly at the lung periphery and are cleared across the alveolar-capillary membrane. Regional alterations in permeability can also be noted using this radionuclide technique. We have measured the pulmonary epithelial permeability in normal subjects and the alteration in smokers, in glue-sniffers, in patients with inhalation burns, in chronic obstructive pulmonary disease (COPD) and in patients with lung metastases from thyroid cancer treated with radioiodine "'I. In the normal volunteers, the time taken for 50% of inhaled ssm'Tc DTPA to be cleared from the lungs (T'/z) was 66 minutes ± 1 sd of 12 mins. The smokers had a mean T'/2 of 20 mins ± I sd 4 min. In the hard-core glue-sniffing group, the majority were smokers who had stopped smoking and gluesniffing for periods varying from 1 day to 42 days, and it was possible to note the changes in clearance times against period of abstinence. In the patients with inhalation burns, there was change in lung clearance arising from pulmonary epithelial damage; these patients showed increased rate of clearance (short T'/) with mean T'/zof 36 min ± I sd of 11 mins, while the retention images revealed regional lung damage in moderately severe inhalation burns. Twenty-four patients with COPD had inhalation scans done with Tc-99m tin colloid radioaerosol, and these images were compared with the perfusion lung scans done with O9mTc macroaggregated albumin (MAA); in general the perfusion images matched the defects noted in the inhalation scans. The 99 mTc DTPA clearance rate in these patients was normal i.e. T'/z = 78 ± 14 mins. In the thyroid cancer patients with lung metastases, who had high doses of radioiodine treatment, the T'/ values were normal or prolonged slightly, mean T'/2= 76 min ± 23.
Soluble radioaerosols such as technetium-99m diethylene triamine pentacetate (DTPA) permit simple... more Soluble radioaerosols such as technetium-99m diethylene triamine pentacetate (DTPA) permit simple quantitative studies of alveolar-capillary permeability to be performed, since the submicronic aerosols are deposited mainly at the lung periphery and are cleared across the alveolar-capillary membrane. Regional alterations in permeability can also be noted using this radionuclide technique. We have measured the pulmonary epithelial permeability in normal subjects and the alteration in smokers, in glue-sniffers, in patients with inhalation burns, in chronic obstructive pulmonary disease (COPD) and in patients with lung metastases from thyroid cancer treated with radioiodine "'I. In the normal volunteers, the time taken for 50% of inhaled ssm'Tc DTPA to be cleared from the lungs (T'/z) was 66 minutes ± 1 sd of 12 mins. The smokers had a mean T'/2 of 20 mins ± I sd 4 min. In the hard-core glue-sniffing group, the majority were smokers who had stopped smoking and gluesniffing for periods varying from 1 day to 42 days, and it was possible to note the changes in clearance times against period of abstinence. In the patients with inhalation burns, there was change in lung clearance arising from pulmonary epithelial damage; these patients showed increased rate of clearance (short T'/) with mean T'/zof 36 min ± I sd of 11 mins, while the retention images revealed regional lung damage in moderately severe inhalation burns. Twenty-four patients with COPD had inhalation scans done with Tc-99m tin colloid radioaerosol, and these images were compared with the perfusion lung scans done with O9mTc macroaggregated albumin (MAA); in general the perfusion images matched the defects noted in the inhalation scans. The 99 mTc DTPA clearance rate in these patients was normal i.e. T'/z = 78 ± 14 mins. In the thyroid cancer patients with lung metastases, who had high doses of radioiodine treatment, the T'/ values were normal or prolonged slightly, mean T'/2= 76 min ± 23.
Soluble radioaerosols such as technetium-99m diethylene triamine pentacetate (DTPA) permit simple... more Soluble radioaerosols such as technetium-99m diethylene triamine pentacetate (DTPA) permit simple quantitative studies of alveolar-capillary permeability to be performed, since the submicronic aerosols are deposited mainly at the lung periphery and are cleared across the alveolar-capillary membrane. Regional alterations in permeability can also be noted using this radionuclide technique. We have measured the alteration in pulmonary epithelial permeability in normal subjects and in patients with inhalation burns using a computer-linked gamma-camera. In the normal volunteers, the time taken for 50% of inhaled Tc-99m DTPA to be cleared from the lungs (T1/2) was 66 minutes +/- 1sd of 12 minutes. In the 42 patients with inhalation burns, besides the T1/2, retention images of uncleared Tc-99m DTPA in the lungs were obtained to note regional differences, if any, in lung clearance arising from pulmonary epithelial damage; these patients showed increased rate of clearance (short T1/2) with mean T1/2 of 36 minutes +/- 1sd of 11 minutes, while the retention images revealed regional lung damage in moderately severe inhalation burns. In 18 patients with abnormal T1/2, 16 (89%) had abnormal bronchoscopy findings. Fifteen patients also had lung perfusion scans with Tc-99m MAA (macroaggregated albumin). The regional defects in perfusion when present were generally matched with the defects seen on ventilation scans. The Tc-99m DTPA lung clearance measurement and imaging has clinical usefulness in suspected inhalation burns.
This study aims to examine the usefulness of fluorine-18-fluorodeoxyglucose (FDG) positron emissi... more This study aims to examine the usefulness of fluorine-18-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in thyroid carcinoma patients with elevated serum thyroglobulin (Tg) but negative iodine-131 (I-131) whole body scans. 17 patients with differentiated thyroid carcinoma who underwent FDG PET/CT scans were reviewed retrospectively over a period of one year from July 2003 to June 2004. All these patients had completion thyroidectomy and subsequently presented with elevated serum Tg but negative post-therapy I-131 whole body scans. Nine of these patients underwent FDG PET/CT in a hypothyroid state, while the remainder underwent FDG PET/CT while on thyroxine replacement. 15 out of 17 PET/CT scans revealed lesions consistent with metastases, giving a sensitivity of 88.2 percent. Four of these patients were amendable to surgical treatment. Two scans were negative. FDG PET/CT is a sensitive diagnostic tool to detect radioiodine-negative recurrences/met...
In recent years, 99mTechnetium IDA hepatobiliary scintigraphy has been widely accepted as a highl... more In recent years, 99mTechnetium IDA hepatobiliary scintigraphy has been widely accepted as a highly sensitive and fairly accurate test in the diagnosis of biliary atresia and evaluation of neonatal jaundice. Over a period of 4 years from 1982 to 1986, a total of 110 paediatric patients had undergone 99mTechnetium IDA hepatobiliary scans in our department for prolonged neonatal jaundice. Their scans were reviewed to evaluate the role of this nuclear imaging technique in the diagnosis of biliary atresia. There were 43 true positive and 49 true negative scans. No false negative scan was encountered in our study. Hence the sensitivity was 100%. However, out of the 110 scans, there was misdiagnosis of biliary atresia in 18 cases. This gave a specificity of 73% with an accuracy of 84%. From this study we concluded that 99mTechnetium IDA imaging is a highly sensitive test in the screening of biliary atresia. However, its specificity is possibly limited by the short half life of the radioisotope 99mtechnetium in delayed 24 hr imaging and we feel that this could be improved by using slightly higher doses than what we are presently using.
It has long been recognised that significant bone tracer localisation in the myocardium is a good... more It has long been recognised that significant bone tracer localisation in the myocardium is a good indicator for amyloid involvement of the heart in the clinical context of systemic amyloidosis. In this case report, although myocardial tissue diagnosis of amyloidosis was not made, the massive myocardial uptake of bone tracer strongly suggested the presence of amyloid infiltration in the heart, and this finding eventually led to the histological diagnosis of familial amyloid polyneuropathy by skin and sural nerve biopsy. Interesting findings were noted in the single photon emission computerised tomography (SPECT) studies of the myocardium with Technetium-99m diphosphono-propanedicarboxylic acid bone agent and Technetium-99m sestamibi myocardial perfusion agent. Such findings suggest that there is a lack of correlation between the intensity of myocardial uptake of bone tracer and viability of the myocardium, and that amyloid will not deposit in infarcted myocardial tissue.
An ideal diagnostic imaging method in cancer management should be one which surveys the entire bo... more An ideal diagnostic imaging method in cancer management should be one which surveys the entire body for occult or small tumour foci in a single procedure. Imaging with radiolabelled antibodies appears to have such potential if the limiting factors which we have encountered in the last 40 years can be completely eliminated. These factors include antibody-dependent factors, radionuclide-dependent factors, host-dependent factors and imaging modality-dependent factors. Advances in immunology and bio-genetic engineering have enabled production of various antibody fragments and genetically engineered antibody molecules (i.e. chimeric/humanized antibodies and the single-chain antigen binding protein), giving a promise of overcoming the problem of cross-reactivity and host immuno-response. The rapid development in radiopharmacy and labelling chemistry has led to the establishment of various pre-targetted methods which are aimed to improve the tumour to non-tumour ratio. The recent success of producing Tc99m labelled monoclonal antibodies preparation in a kit form has certainly encouraged its clinical applications and made antibody imaging a less tedious task. The progression in computer technology has made &quot;image fusion&quot; possible and hence improve the accuracy of anatomical localization of tumour foci in antibody imaging. It would appear possible to overcome most, if not all, of the limiting factors mentioned above in the near future. The prospect of radiolabelled antibodies in tumour imaging is promising and the dream of a &quot;magic bullet&quot; will soon be fulfilled.
Oral thyrotrophin-releasing hormone (TRH) and lithium were given to patients on follow-up for wel... more Oral thyrotrophin-releasing hormone (TRH) and lithium were given to patients on follow-up for well-differentiated thyroid carcinoma to see their effect on serum thyrotrophin level (TSH) and radioiodine (I-131) uptake (RAIU). The study was randomised and doubled-blinded and consisted of a total of 19 patients in 3 groups. Group 1 received placebo and TRH, group 2 received lithium and placebo, and group 3 received lithium and TRH. Serum TSH and RAIU at 24 hours were measured before, and after treatment, with TRH, lithium, and/or placebo. In group 1, mean (+/-SEM) TSH increased from 48.9 (+/-15.2) mU/l to 148.2 (+/-48.0) mU/l (p &lt; 0.05); in group 2, the change of 24.9 (+/- 15.9) mU/l to 31.7 (+/-14.1) mU/l in TSH was not statistically significant; and in group 3, TSH increased from 108.1 (+/-13.8) mU/l to 187.0 (+/-39.1) mU/l (p &lt; 0.05). However, despite the significant change in TSH, there was no significant increase in I-131 uptake in any group: 7.70% to 10.43%, 7.15% to 7.43% and 2.49% to 2.61%, in groups 1, 2 and 3 respectively (p &gt; 0.05). We conclude that while oral TRH will increase endogenous serum TSH significantly, there is no significant increase in I-131 uptake. Lithium was not an useful adjunct in increasing serum TSH or I-131 uptake in these patients.
While continuous ambulatory peritoneal dialysis (CAPD) offers several advantages over haemodialys... more While continuous ambulatory peritoneal dialysis (CAPD) offers several advantages over haemodialysis in patients with end-stage renal disease, several complications have been recognised. The intraperitoneal instillation of dialysate increases intra-abdominal pressure and consequently predisposes to leaks and herniations through defects in the abdominal wall. This can lead to disruption of CAPD therapy. Peritoneal scintigraphy with Tc99m colloid has been used to identify such leaks of dialysate. This report analyses the clinical role of peritoneal scintigraphy in patients on the CAPD programme in the Singapore General Hospital. The results of 25 scans performed over a two-and-a-half year period were correlated with clinical and surgical findings. The clinical presentations of suspected dialysate leakage were varied, but can be broadly classified into three subsets for this analysis: (A) swellings confined to the inguinal and genital region, (B) peri-catheter, umbilical and incisional swellings, and (C) diffuse pattern of swellings in the abdominal wall, pelvic and genital region. In group A, the scan proved to be clearly helpful, correctly identifying 10/10 inguinal hernias, all of which resolved after herniorrhaphy. In group B, the scan correctly identified 7/9 leaks and hernias in the ventral abdominal wall. There was one false negative scan in a patient with a peri-catheter leak, and an equivocal result in another with fluid leakage in the lower anterior abdominal wall. In group C, which presented the greatest difficulty in clinical diagnosis, 2/3 cases were correctly diagnosed by scintigraphy. An equivocal result was seen in a patient who had had multiple operations for recurrent incisional hernias.(ABSTRACT TRUNCATED AT 250 WORDS)
Reverse redistribution (RR) is the apparent worsening of a stress-induced defect or the appearanc... more Reverse redistribution (RR) is the apparent worsening of a stress-induced defect or the appearance of a new defect in the myocardium in the delayed thallium images. This has been linked to the presence of coronary artery disease. In this article, we examine the incidence of this phenomenon in our local population, and its pathophysiological significance.
Background Isotope proctograms (IP) or colonic transit studies (CTS) are usually performed separa... more Background Isotope proctograms (IP) or colonic transit studies (CTS) are usually performed separately for evacuatory and motility disorders of the lower GI tract. Aim To evaluate any associated colonic motility disorders in patients with evacuatory difficulties. Methods In a retrospective review, 86 patients with evacuatory difficulties were referred for IP over a 3 year period. Sixteen of these patients, who also had CTS, were reviewed for this study. Results All 16 patients had abnormalities in both studies. In 16 IP studies, rectoceles were identified in 11 patients, 3 patients were unable to defaecate but clinically had rectoceles and 2 patients had prior repair of rectoceles. All 16 CTS were abnormal; 8 patients had rightsided delay and 6 had generalized delay, indicating slow colonic transit. Two further patients had left-sided delay, indicating nearly normal colonic transit but impaired rectal function. Mean rectocele sizes were 2.9 and 3.6 cm respectively for right sided and generalized delay groups. Conclusions There is a close association between lower GI tract evacuatory and motility disorders and we recommend performing both IP and CTS in patients referred for investigation of evacuatory difficulties. 3.11 (1.49) 2.7-4.0 < 0.001
Experimental and Clinical Endocrinology & Diabetes, 2008
Radioiodine (I-131) is a useful therapeutic modality of hyperthyroidism when medical therapy fail... more Radioiodine (I-131) is a useful therapeutic modality of hyperthyroidism when medical therapy fails. Traditionally, the nuclear physicians undertake the prescription of I-131 therapy. However, endocrinologists are increasingly being recognized for their competence in prescribing individualized doses of I-131 for the treatment of various thyroid disorders. In this pilot prospective study, we collaborated with our nuclear medicine colleagues to determine the outcomes of 80 patients with hyperthyroidism who underwent I-131 ablation as prescribed by the endocrinologist. Doses administered were based primarily on thyroid volume with adjustments contingent on adverse factors, and fixed assumptions on target absorbed dose (R) and uptake (U) were used. Seventy-three had Graves&#39; disease (GD) and seven had toxic nodular goitre (TNG) or toxic adenomas (AFTN). Therapeutic success was defined as achievement of hypothyroidism or euthyroidism. 95.9 percent (70 of 73) of GD patients and 85.7 percent (6 of 7) of those with TNG/AFTN achieved successful outcomes after a single dose of endocrinologist-directed I-131 therapy. More than 50 percent of patients became hypothyroid by three months and about two-thirds became hypothyroid by six months post I-131 therapy. Our results indicate that the success rate of endocrinologist-directed I-131 therapy exceeds 95 percent with a single dose and compares favourably with nuclear physician-directed therapy outcomes.
A small 6-cm colonic J-pouch improves stool frequency and continence, without stool evacuation pr... more A small 6-cm colonic J-pouch improves stool frequency and continence, without stool evacuation problems. However, the reservoir function is not improved on physiologic studies. Hence, a scintigraphy technique was devised to study the transit of solid and liquid colonic contents in these patients. Patients were randomly assigned to straight or colonic J-pouch anal anastomoses after ultralow anterior resection. At 1 year after surgery, they were studied by bowel questionnaire, anorectal manometry, and technetium TC 99m tin-colloid liquid test meal/I-131 microcapsule scintigraphy. In the latter, technetium TC 99m tin-colloid was ingested orally to image the colonic liquids. I-131 microcapsules taken simultaneously imaged the solid stools. After ingestion of the radioisotopes, imaging was performed at intervals of 7 to 8, 24, and 56 hours later. Two independent observers noted the presence of technetium TC 99m tin-colloid liquid and I-131 microcapsules in various areas of interest drawn over the colon. There were six patients (5 males, mean age, 61.5 (SE mean, 1.9) years) in the straight, and six patients (5 males, mean age, 63.2 (4.5) years) in the colonic J-pouch group. Stool frequency was more in the straight group (4.8 (0.4) vs. 3 (0.2) stools/day; P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;.001). Continence, evacuation problems, and anorectal physiologic findings were not different. Technetium TC 99m tin-colloid (imaging liquids) transited significantly faster than I-131 microcapsules (imaging solids), at various areas of interest in the colon. In the colonic J-pouch patients, technetium TC 99m tin-colloid liquid was retained significantly longer in the descending colon at 24 hours (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;.05). Stool frequency was higher when technetium TC 99m tin-colloid was not retained in the descending colon at 56 hours (3.3 (0.5) vs. 4.3 (0.4) stools/day) but this did not reach statistical significance. There were no significant differences in the distribution of the ingested I-131 microcapsules between colonic J-pouch and straight groups. Reduced stool frequency after colonic J-pouch may be related to factors causing better retention of liquid stools in the distal colon. No difference in solid stool transit could possibly account for minimal evacuation problems in small pouches.
Http Dx Doi Org 10 1089 Thy 2006 16 461, Jun 1, 2006
Thyroid cancer is among the 10 most common malignancies in populations in the Asia Pacific region... more Thyroid cancer is among the 10 most common malignancies in populations in the Asia Pacific region, where access to various relevant health care resources varies widely. An expert consensus conference was held to define regional patterns of practice and guidelines for optimal management of well-differentiated epithelial thyroid carcinomas. Practice patterns vary from country to country, as would be anticipated form their variety of ethnic and racial populations, health care systems, economies, and cultures. Thyroid cancer care is provided by a number of medical and surgical specialists, usually including endocrinologists. The thyroid surgical skills, experience, and outcomes vary widely in the region. Radioiodine is available, to a greater or lesser extent, is almost all countries. Laboratory services for thyroid function monitoring are universally accessible; thyroglobulin assays are available in most countries. Recombinant thyrotropin is approved for use in only two countries, but can be accessed in some others on a &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;named patient&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; compassionate need basis. Access to advanced imaging, for exampke, positron emission tomography (PET) scanning, is limited to a few countries. In light of these realities, appropriate strategies for initial treatment and postoperative monitoring of patients with thyroid cancer have been defined, and these are presented and discussed.
atients with well-differentiated thyroid cancer are fol lowed up after thyroidectomy by serial se... more atients with well-differentiated thyroid cancer are fol lowed up after thyroidectomy by serial serum thyroglobulin (Tg) estimation and ‘@‘I whole-body scanning. The use of 1311 requires the suspension of thyroxine (L-3,5,3',5'
Annals of the Academy of Medicine, Singapore, 2001
Medullary thyroid carcinoma (MTC) is a rare thyroid malignancy but accounts for a significant mor... more Medullary thyroid carcinoma (MTC) is a rare thyroid malignancy but accounts for a significant mortality. We present 2 cases of MTC and review the literature regarding its management and genetic screening. Patient 1 presented after a routine health screening and subsequently was found to have a germline mutation for MEN 2A. Patient 2 presented with sweating irritability and a thyroid mass which illustrates the progressive relentless nature of the disease and highlights current imaging practice. Both patients underwent extensive surgery and received postoperatively ablative dose of radioactive iodine. Patient 2 also had a large dose I-131 MIBG therapy and further surgery. In Patient 1, postoperative calcitonins remained elevated indicating residual disease. Patient 2 underwent further radioguided surgery; however, his postoperative calcitonins remained elevated. MTC can be relentless. Routine genetic screening of all patients with MTC, Tc-99m pentavalent (V) DMSA imaging, near total t...
atients with well-differentiated thyroid cancer are fol lowed up after thyroidectomy by serial se... more atients with well-differentiated thyroid cancer are fol lowed up after thyroidectomy by serial serum thyroglobulin (Tg) estimation and ‘@‘I whole-body scanning. The use of 1311 requires the suspension of thyroxine (L-3,5,3',5'
Patients with acute coronary syndrome (ACS) often present atypically. In a randomized controlled ... more Patients with acute coronary syndrome (ACS) often present atypically. In a randomized controlled trial, we studied whether adding stress myocardial perfusion imaging (SMPI) to an evaluation strategy for emergency department (ED) patients presenting with chest pain more effectively identifies patients with ACS. Participants were randomized to standard ED chest pain protocol (clinical assessment) or standard protocol supplemented with SMPI results. During 6 hours of electrocardiogram (ECG) monitoring and serial cardiac markers (creatine kinase-MB isoenzyme, troponin), participants developing ST segment changes or elevated cardiac markers were admitted. Those with a negative observation period underwent SMPI (N = 1,004) or clinical assessment (N = 504) based on randomization, and admitted if their SMPI scan was abnormal or senior clinicians found a high or intermediate risk for ACS. SMPI participants had a significantly lower admission rate than clinical assessment participants (10.16% vs 18.45%), with no significant between-group differences in risk of cardiac events (CEs) after 30 days (0.40% vs 0.79%) or 1 year (0.70% vs 0.99%). When added to a standard triage strategy incorporating clinical evaluation, serial ECGs, and cardiac markers, SMPI improved clinical decision making for chest pain patients, significantly reducing the need for hospitalization without an increase in adverse CE rates at 30 days or 1 year.
The incidence of thyroid cancer is low, but when it occurs, it is mainly of the papillary histopa... more The incidence of thyroid cancer is low, but when it occurs, it is mainly of the papillary histopathological type. Although PET/CT has a limited role in the diagnosis, it plays a significant role in the overall post-surgery management of a patient with thyroid cancer. This follow-up role is important, especially in patients with elevated serum thyroglobulin, but negative radioiodine whole body scans. There is increasing evidence that PET/CT should be a part of routine care in the Tg positive Radioiodine scan negative patient.
Soluble radioaerosols such as technetium-99m diethylene triamine pentacetate (DTPA) permit simple... more Soluble radioaerosols such as technetium-99m diethylene triamine pentacetate (DTPA) permit simple quantitative studies of alveolar-capillary permeability to be performed, since the submicronic aerosols are deposited mainly at the lung periphery and are cleared across the alveolar-capillary membrane. Regional alterations in permeability can also be noted using this radionuclide technique. We have measured the pulmonary epithelial permeability in normal subjects and the alteration in smokers, in glue-sniffers, in patients with inhalation burns, in chronic obstructive pulmonary disease (COPD) and in patients with lung metastases from thyroid cancer treated with radioiodine "'I. In the normal volunteers, the time taken for 50% of inhaled ssm'Tc DTPA to be cleared from the lungs (T'/z) was 66 minutes ± 1 sd of 12 mins. The smokers had a mean T'/2 of 20 mins ± I sd 4 min. In the hard-core glue-sniffing group, the majority were smokers who had stopped smoking and gluesniffing for periods varying from 1 day to 42 days, and it was possible to note the changes in clearance times against period of abstinence. In the patients with inhalation burns, there was change in lung clearance arising from pulmonary epithelial damage; these patients showed increased rate of clearance (short T'/) with mean T'/zof 36 min ± I sd of 11 mins, while the retention images revealed regional lung damage in moderately severe inhalation burns. Twenty-four patients with COPD had inhalation scans done with Tc-99m tin colloid radioaerosol, and these images were compared with the perfusion lung scans done with O9mTc macroaggregated albumin (MAA); in general the perfusion images matched the defects noted in the inhalation scans. The 99 mTc DTPA clearance rate in these patients was normal i.e. T'/z = 78 ± 14 mins. In the thyroid cancer patients with lung metastases, who had high doses of radioiodine treatment, the T'/ values were normal or prolonged slightly, mean T'/2= 76 min ± 23.
Soluble radioaerosols such as technetium-99m diethylene triamine pentacetate (DTPA) permit simple... more Soluble radioaerosols such as technetium-99m diethylene triamine pentacetate (DTPA) permit simple quantitative studies of alveolar-capillary permeability to be performed, since the submicronic aerosols are deposited mainly at the lung periphery and are cleared across the alveolar-capillary membrane. Regional alterations in permeability can also be noted using this radionuclide technique. We have measured the pulmonary epithelial permeability in normal subjects and the alteration in smokers, in glue-sniffers, in patients with inhalation burns, in chronic obstructive pulmonary disease (COPD) and in patients with lung metastases from thyroid cancer treated with radioiodine "'I. In the normal volunteers, the time taken for 50% of inhaled ssm'Tc DTPA to be cleared from the lungs (T'/z) was 66 minutes ± 1 sd of 12 mins. The smokers had a mean T'/2 of 20 mins ± I sd 4 min. In the hard-core glue-sniffing group, the majority were smokers who had stopped smoking and gluesniffing for periods varying from 1 day to 42 days, and it was possible to note the changes in clearance times against period of abstinence. In the patients with inhalation burns, there was change in lung clearance arising from pulmonary epithelial damage; these patients showed increased rate of clearance (short T'/) with mean T'/zof 36 min ± I sd of 11 mins, while the retention images revealed regional lung damage in moderately severe inhalation burns. Twenty-four patients with COPD had inhalation scans done with Tc-99m tin colloid radioaerosol, and these images were compared with the perfusion lung scans done with O9mTc macroaggregated albumin (MAA); in general the perfusion images matched the defects noted in the inhalation scans. The 99 mTc DTPA clearance rate in these patients was normal i.e. T'/z = 78 ± 14 mins. In the thyroid cancer patients with lung metastases, who had high doses of radioiodine treatment, the T'/ values were normal or prolonged slightly, mean T'/2= 76 min ± 23.
Soluble radioaerosols such as technetium-99m diethylene triamine pentacetate (DTPA) permit simple... more Soluble radioaerosols such as technetium-99m diethylene triamine pentacetate (DTPA) permit simple quantitative studies of alveolar-capillary permeability to be performed, since the submicronic aerosols are deposited mainly at the lung periphery and are cleared across the alveolar-capillary membrane. Regional alterations in permeability can also be noted using this radionuclide technique. We have measured the alteration in pulmonary epithelial permeability in normal subjects and in patients with inhalation burns using a computer-linked gamma-camera. In the normal volunteers, the time taken for 50% of inhaled Tc-99m DTPA to be cleared from the lungs (T1/2) was 66 minutes +/- 1sd of 12 minutes. In the 42 patients with inhalation burns, besides the T1/2, retention images of uncleared Tc-99m DTPA in the lungs were obtained to note regional differences, if any, in lung clearance arising from pulmonary epithelial damage; these patients showed increased rate of clearance (short T1/2) with mean T1/2 of 36 minutes +/- 1sd of 11 minutes, while the retention images revealed regional lung damage in moderately severe inhalation burns. In 18 patients with abnormal T1/2, 16 (89%) had abnormal bronchoscopy findings. Fifteen patients also had lung perfusion scans with Tc-99m MAA (macroaggregated albumin). The regional defects in perfusion when present were generally matched with the defects seen on ventilation scans. The Tc-99m DTPA lung clearance measurement and imaging has clinical usefulness in suspected inhalation burns.
This study aims to examine the usefulness of fluorine-18-fluorodeoxyglucose (FDG) positron emissi... more This study aims to examine the usefulness of fluorine-18-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in thyroid carcinoma patients with elevated serum thyroglobulin (Tg) but negative iodine-131 (I-131) whole body scans. 17 patients with differentiated thyroid carcinoma who underwent FDG PET/CT scans were reviewed retrospectively over a period of one year from July 2003 to June 2004. All these patients had completion thyroidectomy and subsequently presented with elevated serum Tg but negative post-therapy I-131 whole body scans. Nine of these patients underwent FDG PET/CT in a hypothyroid state, while the remainder underwent FDG PET/CT while on thyroxine replacement. 15 out of 17 PET/CT scans revealed lesions consistent with metastases, giving a sensitivity of 88.2 percent. Four of these patients were amendable to surgical treatment. Two scans were negative. FDG PET/CT is a sensitive diagnostic tool to detect radioiodine-negative recurrences/met...
In recent years, 99mTechnetium IDA hepatobiliary scintigraphy has been widely accepted as a highl... more In recent years, 99mTechnetium IDA hepatobiliary scintigraphy has been widely accepted as a highly sensitive and fairly accurate test in the diagnosis of biliary atresia and evaluation of neonatal jaundice. Over a period of 4 years from 1982 to 1986, a total of 110 paediatric patients had undergone 99mTechnetium IDA hepatobiliary scans in our department for prolonged neonatal jaundice. Their scans were reviewed to evaluate the role of this nuclear imaging technique in the diagnosis of biliary atresia. There were 43 true positive and 49 true negative scans. No false negative scan was encountered in our study. Hence the sensitivity was 100%. However, out of the 110 scans, there was misdiagnosis of biliary atresia in 18 cases. This gave a specificity of 73% with an accuracy of 84%. From this study we concluded that 99mTechnetium IDA imaging is a highly sensitive test in the screening of biliary atresia. However, its specificity is possibly limited by the short half life of the radioisotope 99mtechnetium in delayed 24 hr imaging and we feel that this could be improved by using slightly higher doses than what we are presently using.
It has long been recognised that significant bone tracer localisation in the myocardium is a good... more It has long been recognised that significant bone tracer localisation in the myocardium is a good indicator for amyloid involvement of the heart in the clinical context of systemic amyloidosis. In this case report, although myocardial tissue diagnosis of amyloidosis was not made, the massive myocardial uptake of bone tracer strongly suggested the presence of amyloid infiltration in the heart, and this finding eventually led to the histological diagnosis of familial amyloid polyneuropathy by skin and sural nerve biopsy. Interesting findings were noted in the single photon emission computerised tomography (SPECT) studies of the myocardium with Technetium-99m diphosphono-propanedicarboxylic acid bone agent and Technetium-99m sestamibi myocardial perfusion agent. Such findings suggest that there is a lack of correlation between the intensity of myocardial uptake of bone tracer and viability of the myocardium, and that amyloid will not deposit in infarcted myocardial tissue.
An ideal diagnostic imaging method in cancer management should be one which surveys the entire bo... more An ideal diagnostic imaging method in cancer management should be one which surveys the entire body for occult or small tumour foci in a single procedure. Imaging with radiolabelled antibodies appears to have such potential if the limiting factors which we have encountered in the last 40 years can be completely eliminated. These factors include antibody-dependent factors, radionuclide-dependent factors, host-dependent factors and imaging modality-dependent factors. Advances in immunology and bio-genetic engineering have enabled production of various antibody fragments and genetically engineered antibody molecules (i.e. chimeric/humanized antibodies and the single-chain antigen binding protein), giving a promise of overcoming the problem of cross-reactivity and host immuno-response. The rapid development in radiopharmacy and labelling chemistry has led to the establishment of various pre-targetted methods which are aimed to improve the tumour to non-tumour ratio. The recent success of producing Tc99m labelled monoclonal antibodies preparation in a kit form has certainly encouraged its clinical applications and made antibody imaging a less tedious task. The progression in computer technology has made &quot;image fusion&quot; possible and hence improve the accuracy of anatomical localization of tumour foci in antibody imaging. It would appear possible to overcome most, if not all, of the limiting factors mentioned above in the near future. The prospect of radiolabelled antibodies in tumour imaging is promising and the dream of a &quot;magic bullet&quot; will soon be fulfilled.
Oral thyrotrophin-releasing hormone (TRH) and lithium were given to patients on follow-up for wel... more Oral thyrotrophin-releasing hormone (TRH) and lithium were given to patients on follow-up for well-differentiated thyroid carcinoma to see their effect on serum thyrotrophin level (TSH) and radioiodine (I-131) uptake (RAIU). The study was randomised and doubled-blinded and consisted of a total of 19 patients in 3 groups. Group 1 received placebo and TRH, group 2 received lithium and placebo, and group 3 received lithium and TRH. Serum TSH and RAIU at 24 hours were measured before, and after treatment, with TRH, lithium, and/or placebo. In group 1, mean (+/-SEM) TSH increased from 48.9 (+/-15.2) mU/l to 148.2 (+/-48.0) mU/l (p &lt; 0.05); in group 2, the change of 24.9 (+/- 15.9) mU/l to 31.7 (+/-14.1) mU/l in TSH was not statistically significant; and in group 3, TSH increased from 108.1 (+/-13.8) mU/l to 187.0 (+/-39.1) mU/l (p &lt; 0.05). However, despite the significant change in TSH, there was no significant increase in I-131 uptake in any group: 7.70% to 10.43%, 7.15% to 7.43% and 2.49% to 2.61%, in groups 1, 2 and 3 respectively (p &gt; 0.05). We conclude that while oral TRH will increase endogenous serum TSH significantly, there is no significant increase in I-131 uptake. Lithium was not an useful adjunct in increasing serum TSH or I-131 uptake in these patients.
While continuous ambulatory peritoneal dialysis (CAPD) offers several advantages over haemodialys... more While continuous ambulatory peritoneal dialysis (CAPD) offers several advantages over haemodialysis in patients with end-stage renal disease, several complications have been recognised. The intraperitoneal instillation of dialysate increases intra-abdominal pressure and consequently predisposes to leaks and herniations through defects in the abdominal wall. This can lead to disruption of CAPD therapy. Peritoneal scintigraphy with Tc99m colloid has been used to identify such leaks of dialysate. This report analyses the clinical role of peritoneal scintigraphy in patients on the CAPD programme in the Singapore General Hospital. The results of 25 scans performed over a two-and-a-half year period were correlated with clinical and surgical findings. The clinical presentations of suspected dialysate leakage were varied, but can be broadly classified into three subsets for this analysis: (A) swellings confined to the inguinal and genital region, (B) peri-catheter, umbilical and incisional swellings, and (C) diffuse pattern of swellings in the abdominal wall, pelvic and genital region. In group A, the scan proved to be clearly helpful, correctly identifying 10/10 inguinal hernias, all of which resolved after herniorrhaphy. In group B, the scan correctly identified 7/9 leaks and hernias in the ventral abdominal wall. There was one false negative scan in a patient with a peri-catheter leak, and an equivocal result in another with fluid leakage in the lower anterior abdominal wall. In group C, which presented the greatest difficulty in clinical diagnosis, 2/3 cases were correctly diagnosed by scintigraphy. An equivocal result was seen in a patient who had had multiple operations for recurrent incisional hernias.(ABSTRACT TRUNCATED AT 250 WORDS)
Reverse redistribution (RR) is the apparent worsening of a stress-induced defect or the appearanc... more Reverse redistribution (RR) is the apparent worsening of a stress-induced defect or the appearance of a new defect in the myocardium in the delayed thallium images. This has been linked to the presence of coronary artery disease. In this article, we examine the incidence of this phenomenon in our local population, and its pathophysiological significance.
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