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PubMed1988

Improvement of myocardial perfusion after thrombolysis assessed by thallium-201 exercise scintigraphy. Report of the Working Group on Thrombolytic Therapy in Acute Myocardial Infarction of the Netherlands Interuniversity Institute of Cardiology.

The effects of recanalization by early intracoronary streptokinase in acute myocardial infarction on myocardial perfusion were studied in a subset of 236 out of 533 patients enrolled in a prospective multicentre trial, randomly allocated to either conventional treatment or to thrombolysis. Maximal symptom-limited thallium-201 stress testing was performed nine to 14 (median 12) weeks after the acute event in 236 patients with a first myocardial infarction, of whom 108 patients were allocated to conventional treatment and 128 patients to thrombolysis. Three-view thallium exercise and redistribution scintigrams were divided into eight segments. The number of normal thallium segments at redistribution was 5.3 +/- 1.6 (mean +/- SD) in the control group and 5.8 +/- 1.6 in the thrombolysis group (P less than 0.01), indicating increased myocardial perfusion after early thrombolytic treatment. This beneficial effect was particularly evident in patients with a first anterior infarction with 4.8 +/- 1.6 normal thallium segments in the control group and 5.9 +/- 1.6 normal segments in the thrombolysis group (P less than 0.001). There was no difference in residual ischaemia during exercise between the control and the thrombolysis group either in the patients with anterior or in those with inferior infarction. It is concluded that early thrombolysis within 4 h after onset of symptoms, in some of the patients followed by angioplasty or coronary artery bypass surgery, leads to sustained improvement of myocardial perfusion at rest without excessive ischaemia during exercise, particularly in patients with acute anterior infarction.

Aged↗
PubMed1979

Reliability of stress thallium-201 scanning in the clinical evaluation of coronary artery disease.

Stress thallium-201 scanning proved to be a highly sensitive and specific screening procedure for myocardial ischemia in 52 consecutive cases with coronary arteriograms. Stress thallium-201 scanning was considerably more accurate and more specific than the exercise electrocardiogram (ECG) as evidenced by a sensitivity of 83% compared to 55%, and a specificity of 94% compared to 82%. When submaximal stress tests were excluded, improved sensitivity of thallium scan to exercise ECG was 95% to 64% with no change in specificity. Factors producing negative thallium scans in the presence of coronary artery disease were: delay in obtaining the first post-exercise scan, positioning and observing variability, severe three-vessel disease uniformly affecting all myocardial segments, and failure to achieve maximal stress testing due to attenuation of the heart-rate response by propranolol or somatic complaints.

Adult↗
PubMed1989

New etiology for intestinal uptake of thallium-201.

A patient with both rest and exercise thallium images for unstable angina demonstrated marked large intestinal uptake of thallium. However, the thallium uptake in the large intestine was noted only after exercise. The only change in the patient status between the two studies was the administration of verapamil. Thus, verapamil administration has been demonstrated to be a new cause for gut uptake of thallium.

Angina, Unstable↗
PubMed1991

Comparison of dipyridamole-echocardiography with dipyridamole-thallium scintigraphy for the diagnosis of myocardial ischemia.

After an intravenous infusion of dipyridamole (0.56 mg/kg), we performed both echocardiography and thallium scintigraphy in 63 patients who were referred for known or suspected coronary artery disease. Of those patients, 25 returned for coronary arteriography within 1 month after the tests, thus forming the study group for this report. Sensitivity for detection of coronary artery disease, when analyzed region-by-region, was 80% for thallium scintigraphy and 57% for echocardiography, whereas specificity was 85% and 98%, respectively. When evaluating individual patients for the presence or absence of ischemia, we found a sensitivity of 95% for scintigraphy and 58% for echocardiography; corresponding specificities were 50% and 100%. By using arteriography as the gold standard for comparison, it appears that thallium scintigraphy has a significantly higher sensitivity but lower specificity for the detection of coronary artery disease than does echocardiography. Echocardiography may, however, be a useful adjunct to thallium scintigraphy in the evaluation of patients with coronary artery disease.

Coronary Disease↗
PubMed1994

Diffuse thallium lung uptake in Pneumocystis carinii pneumonia.

Five patients with AIDS with Pneumocystis carinii pneumonia (PCP) showed diffuse bilateral lung uptake on sequential thallium and gallium scans. This creates a problem in the sequential use of these tests for the differentiation of Kaposi's sarcoma from acute inflammatory or other malignant diseases. In Kaposi's sarcoma, thallium uptake is usually focal and not diffuse unless associated with other pathology. However, in PCP the diffuse thallium lung uptake may be due to congestion, increased vascular permeability, and extravasation of thallium into the lung parenchyma.

AIDS-Related Opportunistic Infections↗
PubMed1993

A comparison of the redistribution and reinjection techniques in dipyridamole thallium tomography.

The effect of the injection of additional thallium after a redistribution study and prior to a further resting study was evaluated in 21 patients with angiographically proven coronary artery disease. Using dipyridamole as the stress mechanism, the studies were carried out tomographically and the results analysed quantitatively with the Bull's-eye technique. Two patients had normal scans. Of the remaining 19, 11 patients had a perfusion defect which appeared irreversible on redistribution imaging. However, six of these patients demonstrated improved or normal uptake after the second injection of thallium. Of the eight patients with a reversible defect, two revealed considerably greater reversibility after reinjection. These results indicate that the reinjection of thallium prior to the resting study significantly (P < 0.02) improves the detection rate of ischaemia during dipyridamole thallium tomography.

Coronary Disease↗
PubMed1985

Right ventricular visualization by thallium 201 myocardial scintigraphy in chronic obstructive pulmonary disease.

The right ventricle is not normally displayed by studies with thallium 201 in patients at rest, but it can be shown by thallium 201 myocardial scintigraphy with pressure or volume overload of the right ventricle and with right ventricular hypertrophy. We sought to determine the frequency of right ventricular demonstration by thallium 201 in 20 patients at rest, who had chronic obstructive pulmonary disease of varying severity studied at baseline. The ventricle was viewed in 11 of 20 patients (55%); these patients had significantly lower values for forced expiratory volume in one second (FEV1) and PO2. Eight patients had catheterization of the right side of the heart; mean pulmonary artery pressure and pulmonary vascular resistance were significantly higher in patients with right ventricular visualization. We conclude that thallium 201 scintigraphy frequently shows the right ventricle in patients with chronic obstructive pulmonary disease and that such visualization correlates with the severity of the ventilatory defect and with pulmonary hypertension.

Aged↗
PubMed1993

The long-term predictive value of an exercise thallium-201 scintigraphy for patients with acute chest pain but without myocardial infarction.

BACKGROUND: Patients who are hospitalized because of chest pain and suspected acute myocardial infarction, but in whom the diagnosis is ruled out, are at high risk for subsequent cardiac events (cardiac death or nonfatal acute myocardial infarction). Risk stratification was done for 158 such patients who underwent exercise thallium-201 scintigraphy at the time of discharge. METHODS: Thirty-eight patients (24%) were women, and all patients were followed for 7 years. The diagnostic sensitivity, specificity, and predictive value of thallium scintigraphy for the identification of patients having subsequent cardiac events during follow-up was calculated. RESULTS: A cardiac event occurred in 41 patients during the follow-up period. Presence of both transient and permanent defects and abnormal ST-segment responses during thallium scintigraphy were significantly associated with an impaired prognosis (P < 0.0001). The highest sensitivity (85%) was achieved by the combination of transient defect with or without persistent defect and with or without abnormal ST-segment response. The highest specificity was provided by a transient defect (90%), and the predictive value of a positive test result was 60%. Seventeen of 29 patients with a transient defect had a cardiac event during follow-up. Patients with normal test results had excellent prognoses; 93% of 82 patients were free of cardiac events during follow-up. CONCLUSIONS: Exercise thallium-201 scintigraphy is suitable for long-term risk stratification in patients with chest pain and suspected but unconfirmed myocardial infarction, because high- and very low-risk subsets can be identified at the time of discharge.

Adult↗
PubMed1993

Age- and sex-related differences in the use of coronary angiography in patients undergoing adenosine SPECT thallium imaging.

BACKGROUND: Recent reports suggest sex-related differences in the management of patients with coronary artery disease. METHODS: This study examined the pattern of use of coronary angiography in 535 patients initially referred for adenosine single photon emission computed tomography (SPECT) thallium imaging. RESULTS: Coronary angiography was carried out more often in patients under 70 years of age than those over 70 years of age [107 out of 322 (33%) versus 50 out of 213 (23%), P < 0.01]. Even in patients with abnormal adenosine SPECT thallium results, coronary angiography was less frequently performed in the elderly [40 out of 130 (31%) versus 82 out of 178 (46%), P < 0.01]. Women underwent coronary angiography less often than men [56 out of 261 (21%) versus 101 out of 274 (37%), P < 0.0002]. This difference was due to differences in patients under 70 years of age [31 out of 138 women (22%) versus 76 of 184 men (41%), P < 0.003)], but not in patients over 70 years of age. In patients with abnormal adenosine thallium image results, the difference between men and women was still present: 37 out of 112 women (33%) versus 85 of 196 men (43%) underwent coronary angiography (P = 0.05). Stepwise discriminant analysis of clinical and scintigraphic variables identified four independent predictors of the need for coronary angiography; the abnormal thallium image results (chi 2 = 33, P < 0.0001); the size of the perfusion abnormality (chi 2 = 7, P < 0.01); sex (chi 2 = 7, P < 0.01) and age (chi 2 = 4, P < 0.05). CONCLUSION: Coronary angiography is less often performed in women and elderly patients even when initial screening results are abnormal. The relation of this observation to subsequent clinical course and events requires further studies.

Adenosine↗
PubMed1996

Comparative diagnostic value of dobutamine stress echocardiography and stress thallium-201 single-photon-emission computed tomography for detecting coronary artery disease in women.

BACKGROUND: The non-invasive diagnosis of coronary artery disease in women remains a difficult clinical problem. The aim of this study was to investigate the comparative diagnostic accuracy of dobutamine stress echocardiography and stress thallium-201 single-photon-emission computed tomography (SPECT) in women who were suspected to have coronary artery disease. METHODS: We studied 70 consecutive women who had not had a previous myocardial infarction (mean age 65 years) who underwent dobutamine stress echocardiography and quantitative coronary angiography. Sixty-one of the 70 women were also subjected to thallium-201 SPECT, with exercise or dipyridamole administration as the stressor, during the same period. A positive diagnosis was based on the detection of inducible wall motion abnormality and the presence of stress-induced abnormalities of perfusion. RESULTS: No significant complication occurred in any patient during dobutamine stress echocardiography (peak dose 31 +/- 9 micrograms/kg per min, atropine administered to 13 patients, peak heart rate 120 +/- 19 beats/min). Coronary artery disease (> or = 50% diameter stenosis) was present in 20 (29%) patients, nine with one-vessel and 11 with multivessel disease. The sensitivity, specificity and diagnostic accuracy of dobutamine stress echocardiography for detecting coronary artery disease were 75, 92 and 87% respectively. In 61 patients who underwent both stress tests, the sensitivity, specificity and accuracy of dobutamine stress echocardiography and stress thallium-201 SPECT were 72 versus 78%, 91 versus 70% (P < 0.05) and 85 versus 72%, respectively. CONCLUSIONS: Dobutamine stress echocardiography appears to be of comparable sensitivity and higher specificity with stress thallium-201 SPECT for noninvasive detection of coronary artery disease in women.

Adult↗
PubMed1980

Serial thallium-201 myocardial perfusion scanning in acute myocardial infarction.

Serial myocardial perfusion scanning was performed in 30 patients with acute myocardial infarction. Scanning was commenced less than six hours after onset of symptoms in 12 patients, 6-24 hr in eight and 24-120 hr in ten. All 30 patients showed thallium defects corresponding to the ECG site of infarction. When initial and four-hour scans were compared, constant defects were present in ten patients and changing defects in 20. Of the 169 segments with defects on the initial scan, 117 (69%) remained constant, 41 (24%) improved, and 11 (7%) deteriorated. More defects changed in the patients scanned earlier (less than 6 hr) than in the patients scanned later (more than 6 hr) (42% vs 23% P less than 0.025), and more defects changed in patients with subendocardial compared to transmural infarction (49% vs 26% P less than 0.025). During a mean follow-up period of 18 months, seven patients died, two developed left ventricular failure, seven had angina and 14 remained asymptomatic. The non-survivors had significantly larger thallium defects than the survivors (55 +/- 15% vs 37 +/- 14%, P less than 0.005). Serial change on thallium scanning was not related to the clinical course. Perfusion defects on serial thallium scanning are useful in detecting and localising early myocardial infarction and the size of defects is related to the subsequent clinical course. Changing perfusion defects on serial scanning suggesting peri-infarctional ischaemia are common, and make assessment of therapeutic interventions to limit infarct size difficult, but are not related to the clinical course.

Adult↗
PubMed1995

SPECT imaging of gliomas with Thallium-201 and Technetium-99m-HMPAO.

Sequential Thallium-201 and Technetium-99m-HMPAO SPECT images were obtained from 7 patients with high-grade gliomas and 5 patients with low-grade gliomas. The histo-pathological tumor-type was verified from either biopsy specimens or resected tissue from surgery. There was an intense uptake of Thallium-201 in all high-grade gliomas. Compared to the contralateral hemisphere the mean uptake was 4.6 times higher. Low-grade gliomas showed only a marginally increased Thallium-201 uptake (1.4 times). No overlap existed between the two groups. There was no correlation between Technetium-99m-HMPAO uptake and tumor type. Thallium-201 appears to be a promising radiopharmaceutical for differentiating high- and low-grade gliomas, whereas Technetium-99m-HMPAO is not.

Adult↗
PubMed1982

Thallium-201: autoradiography in pigmented mice and melanin-binding in vitro.

Autoradiography with 201Tl+ in C57Bl mice showed a strong labelling of the eye melanin and of pigmented hair follicles. An analysis of the affinity of thallium for pigment from cow eyes indicated a binding to three groups of sites and showed a marked sensitivity to the addition of H+-ions. The results are consistent with the conception that a binding of thallium occurs to the free carboxyl groups of the melanin and that the structure of the polymer has a marked influence on the affinity. Similar results have previously been obtained with other cations. There was no indication that the strong in vivo affinity of thallium to melanin is due to a more firm binding than for other cations which do not localize on melanin in vivo. Instead, the ability of cations to pass the melanocyte membranes and reach the melanin granules is probably decisive to whether a melanin binding will take place in vivo. Toxic effects on the eye and epilation are symptoms of thallium intoxication which may be related to its melanin binding. The fate of 201Tl+ in some other tissues is also described and discussed.

Animals↗
PubMed1979

Thallium-201 myocardial imaging in assessment of results of aortocoronary bypass surgery.

Thirty-six patients were assessed by thallium-201 myocardial imaging before and after aortocoronary bypass operations and the results were compared with evaluation based on symptomatic assessment, exercise testing, and electrocardiography. After operation, the majority of patients were free from symptoms or symptomatically improved with increased exercise duration. Perioperative myocardial damage was shown in eight patients and myocardial ischaemia in 15 patients when assessed by thallium imaging during exercise. Thallium imaging proved more sensitive than electrocardiography in the demonstration of perioperative infarction and in the detection of postoperative ischaemia. Exercise electrocardiography may be misleading after aortocoronary bypass operations. Thallium imaging offers a simple, objective evaluation of the results of revascularisation procedures, throws light on the mechanisms of relief of angina by operation, and helps in the assessment of the patient whose progress is unsatisfactory after operation.

Adult↗
PubMed1982

Postoperative thallium-201 myocardial images. Evidence of regression of right ventricular hypertrophy in man.

Thallium-201 myocardial scintigraphic studies were performed on 24 patients with chronic right ventricular overload before and after surgical correction of haemodynamic overload. The ages of the patients ranged from 20 to 65 years (mean 39 years) at operation. The degree of right ventricular visualisation remained essentially unchanged in an early postoperative study (four to 60 days), though a decrease in right ventricular cavity size was noted in patients with right ventricular volume overload. On later follow-up (18 to 36 months), thallium uptake in the right ventricle was definitely less than before operation in all 13 patients studied at this time. Because thallium-201 radioactivity reflects myocardial blood flow and mass, our study indicates that right ventricular hypertrophy is largely reversible. Thus, thallium-201 myocardial scintigraphy can be used to assess non-invasively regression of right ventricular hypertrophy in patients with right ventricular overload.

Adult↗
PubMed1999

Exercise four hour redistribution thallium-201 single photon emission computed tomography and exercise induced ST segment elevation in detecting the viable myocardium in patients with acute myocardial infarction.

OBJECTIVE: To investigate the specificity and sensitivity of the combination of redistribution in exercise thallium-201 single photon emission computed tomography (SPECT) and exercise induced ST elevation for detecting the viable myocardium in patients with acute myocardial infarction. DESIGN: 37 patients were studied within seven weeks of onset of Q wave myocardial infarction (anterior in 22, inferior in 15). All patients underwent exercise four hour redistribution thallium-201 SPECT and positron emission tomography using fluorine-18-fluorodeoxyglucose (FDG) and nitrogen-13 ammonia under fasting conditions. RESULTS: Sixteen patients showed exercise induced ST elevation >/= 1.5 mm, and 15 of these had increased FDG uptake in the infarct region. Eleven of 16 patients (10 of 11 patients with anterior infarctions) with irreversible thallium-201 defects and increased FDG uptake showed exercise induced ST elevation. The sensitivity, specificity, and predictive accuracy of redistribution, exercise induced ST segment elevation, or both for detecting increased FDG uptake were 82%, 75%, and 67% (94%, 75%, and 91% for anterior infarctions), respectively. CONCLUSIONS: In patients with acute Q wave myocardial infarction, the combination of redistribution in exercise thallium-201 SPECT and exercise induced ST elevation can detect the viable myocardium in the infarct region with high sensitivity and specificity, especially in patients with anterior infarctions.

Adult↗
PubMed1997

Neuropsychology of thallium poisoning.

Cases of thallium poisoning are rare and neuropsychological assessment has only been reported in detail in one other case. In the case reported here, neuropsychological assessments were carried out three, 12, and 54 months after diagnosis of thallium poisoning in a man who had acutely shown a number of neurological signs including confusion and disorientation and generalised slowing of EEG which was more prominent on the left. Evidence suggested that he had been exposed to thallium over a period of weeks. Neuropsychological assessment indicated an unexpected weakness in verbal abilities which persisted. This finding is consistent with the only other published case report which details neuropsychological effects after a single large dose of thallium and which also found a lateralised impairment.

Adult↗
PubMed2004

Erosion of nails following thallium poisoning: a case report.

This case report describes a patient with thallium poisoning caused by repeated exposure to low doses of thallium. Alopecia and nail changes were the most prominent features of this case. There was dystrophy of nails in the form of whitish lunular stripes. This is the first report of complete erosion of proximal parts of nails following thallium poisoning. This case is the first report of thallium poisoning from India occurring from repeated low dose exposure.

Adult↗