Diagnostic value of transient dilatation of the left ventricle in negative dipyridamole-thallium imaging

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Seo, Hiromi; Doi, Y.L.; Yonezawa, Yoshihiro; Chikamori, Taishiro; Yamada, Mitsutoshi; Ozawa, Toshio

1994-01-01

To evaluate the diagnostic value of a transient dilatation of the left ventricle during dipyridamole-thallium imaging (DTI) for detecting significant coronary artery disease (CAD) in patients with negative DTI results, 81 consecutive patients were studied. Twenty one patients (26%) had CAD and 60 patients had normal coronary anatomy (NCA). The initial/delayed ratio of the left ventricular dimension, which was measured as the distance between the 2 peaks of a count profile curve on a 45deg left anterior oblique planar image, was defined as the dilatation ratio (DR) of the left ventricle. Patients with CAD had a higher incidence of chest pain after dipyridamole infusion (35 vs 13%; p 1.03) when it was greater than the mean +2 standard deviations of the DR in NCA patients. Seventy-six percent of CAD patients had an abnormal DR. A stepwise discriminant analysis revealed that an abnormal DR alone had the same ability to predict CAD (sensitivity 76%, specificity 98%, chi-square 80.9, p 1.03) is a highly specific marker for detecting CAD, even in patients with negative dipyridamole-thallium imaging. (author)

Serial thallium-201 myocardial imaging after dipyridamole infusion: diagnostic utility in detecting coronary stenoses and relationship to regional wall motion

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Leppo, J.; Boucher, C.A.; Okada, R.D.; Newell, J.B.; Strauss, H.W.; Pohost, G.M.

1982-01-01

After a 4-minute i.v. dipyridamole infusion, 0.14 mg/kg/min, serial thallium-201 scans were obtained in 60 patients undergoing cardia catheterization. Forty patients had significant (greater than or equal to50% stenosis) coronary artery disease (CAD), and 20 patients had normal coronary arteries or trivial lesions. The images were graded qualitatively for thallium activity by three observers. Sensitivity was 93% (37 of 40) and specificity was 80% (16 of 20). The sensitivity and specificity of the thallium-201 study were not affected by the extent of CAD, the presence of Q waves, or propranolol therapy. Twenty-seven of 37 patients who had initial defects (73%) had complete thallium redistribution of one or more defects. Patient-by-patient anlaysis using a regression model of all patients showed that the fate of a segmental thallium defect predicted abnormal wall motion by angiography better than ECG Q waves. The presence of propranolol therapy or collaterals did not significantly affect the thallium redistribution results. It is concluded that qualitative interpretation by multiple observers of thallium images after dipyridamole infusion is a highly sensitive and specific test for CAD. After dipyridamole, as with exercise stress, the extent of thallium redistribution is related to the degree of myocardial wall motion abnormality

Myocardial uptake and clearance of thallium-201 in normal subjects: comparison of dipyridamole-induced hyperemia with exercise stress

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Ruddy, T.D.; Gill, J.B.; Finkelstein, D.M.; Strauss, H.W.; McKusick, K.A.; Okada, R.D.; Boucher, C.A.

1987-01-01

Thallium-201 uptake and clearance after dipyridamole infusion may differ from that after exercise stress because the hemodynamic effects of these two interventions are different. In this study of normal volunteers, thallium kinetics after dipyridamole (n = 13) were determined from three serial image sets (early, intermediate and delayed) and from serial blood samples and compared with thallium kinetics after exercise (n = 15). Absolute myocardial thallium uptake was greater after dipyridamole compared with exercise (p less than 0.0001), although the relative myocardial distribution was similar. The myocardial clearance (%/h) of thallium was slower after dipyridamole than it was after exercise. Comparing dipyridamole and exercise, the differences in clearance were large from the early to the intermediate image (anterior, -11 +/- 17 versus 24 +/- 5, p = 0.0005; 50 degrees left anterior oblique, -7 +/- 11 versus 15 +/- 8, p = 0.004; 70 degrees left anterior oblique, 3 +/- 9 versus 21 +/- 6, p = 0.001). In contrast, the differences in clearance were small from the intermediate to the delayed image (anterior, 15 +/- 4 versus 20 +/- 2, p = 0.025; 50 degrees left anterior oblique, 15 +/- 4 versus 19 +/- 3, p = 0.13; 70 degrees left anterior oblique, 15 +/- 3 versus 18 +/- 2, p = 0.047). Thallium uptake and clearance in the liver, splanchnic region and spleen were greater after dipyridamole (p less than 0.001). Blood thallium levels were greater after dipyridamole (p less than 0.05) and cleared more slowly (p = 0.07). Thus, myocardial thallium-201 uptake and clearance after dipyridamole infusion differ from thallium kinetics after exercise. This difference is, in part, related to associated differences in extracardiac and blood kinetics. Diagnostic criteria for the detection of abnormal thallium-201 clearance must be specific for the type of intervention

Dipyridamole thallium imaging for detecting cardiac involvement in patients with systemic sclerosis (scleroderma)

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Ishida, Yoshio; Matsubara, Noboru; Tani, Akihiro; Morozumi, Takakazu; Hori, Masatsugu; Kitabatake, Akira; Kamada, Takenobu; Kimura, Kazufumi; Kozuka, Takahiro (Osaka Univ. (Japan). Faculty of Medicine)

1990-02-01

Dipyridamole thallium-201 imaging was carried out in 21 patients with progressive systemic sclerosis (PSS) to assess its value in detecting impaired myocardium and coronary microcirculation associated with PSS. Depending upon the degree of cardiac function, the patients were classified as having either ejection fraction of 50% or more (Group I, n=17) or less than 50% (Group II, n=4). In Group I, four patients had transient defect in which perfusion defects were seen on early images but not seen on delayed images; three had reverse redistribution in which defects were not seen on early images but seen on delayed images; and three had persistent defects which were seen on both early and delayed images. A decreased washout of thallium-201 was seen in 9 patients. In an analysis of both perfusion defects and washout rate, 13 patients (76%) in Group I were found to have abnormal findings. This suggests that disturbed coronary microcirculation or impaired myocardium may frequently develop even when EF is normal. All of the patients categorized as having a decreased cardiac function (Group II) had perfusion defect, suggesting the presence of myocardial fibrosis. In PSS, deterioration of cardiac function seemed to be associated with progression of myocardial fibrosis. Dipyridamole thallium imaging may be a sensitive method for detecting cardiac lesions in PSS. It also has the potential for detecting decreased coronary flow reserve or slightly impaired myocardium even without decreased EF. (N.K.).

Prognostic value of dipyridamole thallium scintigraphy for evaluation of ischemic heart disease

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Hendel, R.C.; Layden, J.J.; Leppo, J.A.

1990-01-01

Exercise testing alone or in combination with thallium scintigraphy has significant prognostic value. In contrast, dipyridamole thallium imaging is not dependent on patients achieving adequate levels of exercise, but no long-term prognostic studies have been reported. Accordingly, imaging results of 516 consecutive patients referred for dipyridamole thallium studies were correlated with subsequent cardiac events, death (n = 23) and myocardial infarction (n = 43) over a mean follow-up period of 21 months. Patients with a history of congestive heart failure, prior myocardial infarction, diabetes mellitus or abnormal scans were significantly more likely to have a cardiac event (p less than 0.03). With use of logistic regression analysis, an abnormal scan was an independent and significant predictor of subsequent myocardial infarction or cardiac death and increased the relative risk of any event more than threefold. The presence of redistribution on thallium scanning further increased the risk of a cardiac event. Survival analysis demonstrated a significant difference between patients with an abnormal or normal thallium scan over a 30 month period. In conclusion, dipyridamole thallium scintigraphy demonstrates prognostic value in a large unselected population and may be an adequate clinical alternative to physiologic exercise testing in the evaluation of coronary heart disease

Risk-benefit of dipyridamole loading thallium-201 myocardial scintigraphy

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Ueshima, Kenji; Ogiu, Naonori; Musha, Takehiko; Moriai, Naoki; Miyakawa, Tomohisa; Nakai, Kenji; Hiramori, Katsuhiko

1995-01-01

This study assessed the accuracy of dipyridamole-stressed thallium-201 scintigraphy in the detection of myocardial ischemia, as well as the associated complications and their background factors. Fifty consecutive patients (33 men and 17 women; a mean age of 67 years) unable to undergo exercise thallium imaging were examined. R waves on resting ECG, the occurrence of ischemic changes on exercise ECG, asynergy on left ventriculography and dobutamine-stressed two-dimensional echocardiography, uptake of FEG on PET, and coronary angiographic findings were comprehensively assessed to determine the accuracy of the present scintigraphy. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were 60.4%, 94.2%, 89.7%, 83.0%, and 82.9%, respectively. These findings yielded satisfactory detectability of dipyridamole-stressed thallium-201 scintigraphy for myocardial ischemia. The present scintigraphy had a high sensitivity and specificity for the left anterior descending artery; however, it had a high specificity but low sensitivity for the other arteries. A majority of complications during the scintigraphy was transient, mild decrease in blood pressure, which was found especially when ischemia was present in the left circumflex artery and chest pain occurred during dipyridamole stress. Dipyridamole stress is considered to be contraindicated for patients with unstable angina. (N.K.)

Myocardial rest iodine-123-β-methyl-iodophenyl-pentadecanoic acid scintigraphy compared with dipyridamole stress thallium-201 scintigraphy in unstable angina

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Misumi, Ikuo; Kimura, Yoshihiro; Hokamura, Youichi; Yamabe, Hiroshige; Ueno, Kazuhiro

1998-01-01

Twelve patients with stable angina and 12 patients with unstable angina underwent rest iodine-123-β-methyl-iodophenyl-pentadecanoic acid (BMIPP), dipyridamole stress thallium scintigraphy and delayed thallium scintigraphy. In stable angina, sensitivity for detecting ischemic segments was higher in dipyridamole thallium (74%) than rest BMIPP (48%) images (p<0.05), but there was no significant difference between the 2 images in unstable angina. In unstable angina, the incidence of segments with higher defect scores on BMIPP images than on delayed thallium images and the opposite pattern was 27 and 5 (p<0.01). In stable angina, there was no difference. The mean defect score on BMIPP (6.3±5.6) was higher than that on delayed thallium scintigraphy (2.9±2.7) and it was almost the same as on the initial dipyridamole stress test (6.5±5.2). In conclusion, BMIPP scintigraphy is safer and may be as useful in detecting myocardial ischemia in patients with unstable angina as thallium scintigraphy. (author)

Prognostic importance of silent myocardial ischemia detected by intravenous dipyridamole thallium myocardial imaging in asymptomatic patients with coronary artery disease

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Younis, L.T.; Byers, S.; Shaw, L.; Barth, G.; Goodgold, H.; Chaitman, B.R.

1989-01-01

One hundred seven asymptomatic patients who underwent intravenous dipyridamole thallium imaging were evaluated to determine prognostic indicators of subsequent cardiac events over an average follow-up period of 14 +/- 10 months. Univariate analysis of 18 clinical, scintigraphic and angiographic variables revealed that a reversible thallium defect, a combined fixed and reversible thallium defect, number of segmental thallium defects and extent of coronary artery disease were significant predictors of subsequent cardiac events. Of the 13 patients who died or had a nonfatal infarction, 12 had a reversible thallium defect. Stepwise logistic regression analysis selected a reversible thallium defect as the only significant predictor of cardiac events. When death or myocardial infarction was the outcome variable, a combined fixed and reversible thallium defect was the only predictor of outcome. In patients without previous myocardial infarction, the cardiac event rate was significantly greater in those with an abnormal versus normal thallium scan (55% versus 12%, p less than 0.001). Thus, intravenous dipyridamole thallium scintigraphy is a useful noninvasive test to risk stratify asymptomatic patients with coronary artery disease. A reversible thallium defect most likely indicates silent myocardial ischemia in a sizable fraction of patients in this clinical subset and is associated with an unfavorable prognosis

A comparison of maximal exercise and dipyridamole thallium-201 planar gated scintigraphy

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Martin, W.; Tweddel, A.C.; Main, G.; Hutton, I.

1992-01-01

Both symptom-limited maximal exercise and intravenously given dipyridamole stress (0.56 mg/kg over 4 min with a 2 min walk) gated thallium scans were performed in 22 patients undergoing coronary arteriography for the assessment of chest pain. All scans were acquired gated to the electrocardiogram in 3 projections and were reported for the presence and extent of defects in 5 myocardial segments in each view. In addition, left and right ventricular myocardial uptake and estimates of right and left lung and liver to left ventricular uptake were assessed relative to the injected dose of thallium-201. Overall, 190/310 segments were abnormal with exercise compared with 169/310 with dipyridamole. Segments were scored greater in extent in 90/310 cases with exercise, compared with 46/310 in which the defect was more extensive with dipyridamole. Non-attenuation corrected percentage myocardial thallium uptakes were similar for both stresses. Left and right lung and liver to left ventricle ratios were all significantly higher with dipyridamole than with exercise. High right and left lung uptakes with dipyridamole were strongly correlated with high exercise values. The liver uptake was weakly correlated between the 2 different stress tests. These results demonstrate that dipyridamole induces fewer and less extensive thallium perfusion defects than maximal exercise, and that liver and lung to myocardial ratios are higher with dipyridamole than with exercise. (orig./MG)

Patients with stable chronic obstructive pulmonary disease can safely undergo intravenous dipyridamole thallium-201 imaging.

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Shaffer, J; Simbartl, L; Render, M L; Snow, E; Chaney, C; Nishiyama, H; Rauf, G C; Wexler, L F

1998-08-01

Patients with chronic obstructive pulmonary disease are usually excluded from intravenous dipyridamole thallium-201 testing. We developed a nurse-administered protocol to screen and pretreat patients so they could be safely tested. We prospectively screened patients referred for intravenous dipyridamole thallium testing and retrospectively reviewed a comparison group of patients who had undergone intravenous dipyridamole testing before our bronchospasm protocol. We studied 492 consecutive patients referred for intravenous dipyridamole thallium testing, separating those with complete data (n = 451) into two groups: group A (n = 72), patients assessed to be at risk for intravenous dipyridamole-induced bronchospasm who received our bronchospasm treatment protocol; and group B (n = 379), patients assessed to be free of risk, who did not receive our bronchospasm protocol. Group C (n = 89) was a retrospective comparison group of patients who had undergone intravenous dipyridamole testing before initiation of the protocol. Patients were considered at risk for an adverse event if any of the following were present: peak flow 400 ml after bronchodilator treatment, wheezing audible with stethoscope, history of chronic obstructive pulmonary disease or asthma or dyspnea on exertion at less than four blocks, or resting respiratory rate >18 breaths/min. The test was considered contraindicated if resting oxygen saturation was respiratory rate stethoscope but without marked respiratory distress), (2) marked events (severe bronchospasm or severe ischemia defined as wheezing audible with or without stethoscope, respiratory rate >20 breaths/min or increased by 10 from pretest evaluation, oxygen desaturation to respiratory rate with decreased mental status], respiratory arrest, chest pain, horizontal ST-segment depression > or =1 mm on the electrocardiogram in any lead, symptomatic hypotension), or (3) other intravenous dipyridamole-induced side effects (persistent headache, dizziness

Myocardial viability in cases with persistent perfusion defects on the dipyridamole thallium-201 scintigram. A comparative study with autopsy findings

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Nakayama, Masafumi; Mashima, Saburo; Ohkawa, Shin-ichiro; Tanno, Munehiko; Yamada, Hideo.

1996-01-01

The aim of this study was to assess the incidence of myocardial infarction among persistent perfusion defects in dipyridamole-stress thallium scintigraphy by inspecting autopsied hearts and to evaluate whether the regional thallium activity of a scintigraphic defect can predict the presence of infarction. Autopsied hearts were compared with dipyridamole myocardial scintigrams undertaken during life in 27 patients (mean age 85±8 years). The time interval from stress testing until death was 428±351 days. Regional thallium uptake of delayed perfusion defect was calculated on the short axis images. The grade of regional myocardial fibrosis in autopsy specimens was also quantified to correlate with the corresponding regional thallium uptake. In 6 of 15 (40%) regions with persistent defects on the scintigram, myocardial infarction was not found at autopsy. Regional thallium-201 uptake of delayed defects < 50% diagnosed infarction with a sensitivity of 82% and a specificity of 80%. A linear correlation (r=-0.67) was observed between percent thallium-201 uptake and the degree of myocardial fibrosis. In conclusion, perfusion defects at 4-hour imaging in dipyridamole-stress testing may overestimate the presence of myocardial infarction and regional thallium-201 activity is helpful in distinguishing between defects with and without infarction. (author)

Preoperative evaluation of myocardial viability by thallium-201 imaging in patients with old myocardial infarction who underwent coronary revascularization

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Naruse, Hitoshi; Ohyanagi, Mitsumasa; Iwasaki, Tadaaki; Miyamoto, Takashi; Fukuchi, Minoru

1992-01-01

The myocardial uptake and redistribution in thallium scintigraphy and the regional wall motion by echocardiography were evaluated by a semi-quantitative method in 42 patients who previously had myocardial infarction (50 target vessels) and underwent coronary revascularization. The aim of this study was to elucidate the significance of the initial image, delayed image and redistribution on thallium-201 scintigraphy for clinical diagnosis of the myocardial viability. As a semi-quantitative analysis, we used a bull's-eye display for thallium image and centerline method for echocardiographic wall motion, and compared the results before and after revascularization. As a result, the thallium grade improved postoperatively in all 17 areas which preoperatively had showed redistribution, and also in 11 of the 32 areas without preoperative redistribution. The sensitivity, specificity and accuracy of preoperative thallium redistribution for predicting myocardial viability were 61%, 100% and 78%, respectively, when the postoperative improvement in the thallium grade was used as the standard. The postoperative probability of improvement in the thallium grade increased in proportion to the preoperative grade (delayed image)(p<0.01). There was no correlation between the preoperative thallium delayed image and postoperative improvement in wall motion. Postoperative improvement in thallium image and wall motion could not be predicted from the preoperative wall motion. Thus, postoperative improvement in thallium images can be anticipated if redistribution is present on the preoperative thallium image, and the preoperative thallium delayed image is useful for predicting myocardial viability. Improvement in wall motion could not be predicted preoperatively by these methods. (author)

Dipyridamole-induced ST segment depression during thallium-201 imaging in patients with coronary artery disease: angiographic and hemodynamic determinants

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Chambers, C.E.; Brown, K.A.

1988-01-01

To examine the angiographic and hemodynamic determinants of dipyridamole-induced ST segment depression in patients with coronary artery disease, 41 patients with angiographically documented coronary disease who underwent dipyridamole-thallium-201 myocardial scintigraphy were studied. Dipyridamole-induced ST depression occurred in 14 (34%) of the 41 patients. Stepwise multivariate logistic regression was performed to compare the predictive value of angiographic findings (good coronary collateral vessels, jeopardized collateral vessels, multivessel disease), hemodynamic changes (changes in heart rate, systolic pressure, diastolic pressure and rate-pressure product), thallium-201 results (perfusion defect, thallium-201 redistribution) and demographic data (age, gender, medications). Only the presence of good coronary collateral vessels (p less than 0.02) and increases in rate-pressure product after dipyridamole infusion (p less than 0.02) were significant multivariate predictors of dipyridamole-induced ST depression. Good collateral vessels were more common in the group with ST depression (11 [79%] of 14) than they were in the group without ST depression (6 [22%] of 27; p less than 0.001). Rate-pressure product increased 2,835 +/- 1,648 beats/min.mm Hg in the group with ST depression compared with 1,179 +/- 1,417 beats/min.mm Hg in patients without ST depression (p less than 0.005). In conclusion, dipyridamole-induced ST segment depression in patients with coronary artery disease appears to be related to 1) the presence of good coronary collateral vessels, which may act by facilitating coronary steal, and 2) increases in rate-pressure product, reflecting increased myocardial oxygen demand. These observations may explain the lack of prognostic value of dipyridamole-induced ST segment depression described in previous reports

Effects of dipyridamole and aminophylline on hemodynamics, regional myocardial blood flow and thallium-201 washout in the setting of a critical coronary stenosis

International Nuclear Information System (INIS)

Granato, J.E.; Watson, D.D.; Belardinelli, L.; Cannon, J.M.; Beller, G.A.

1990-01-01

Experiments were performed to characterize the interaction of intravenous dipyridamole and aminophylline on thallium-201 transport kinetics, regional myocardial blood flow and systemic hemodynamics in the presence of a critical coronary artery stenosis. In 12 dogs with a critical left anterior descending coronary artery stenosis, arterial pressure decreased from a mean value (+/- SEM) of 107 +/- 6 to 94 +/- 3 mm Hg and distal left anterior descending artery pressure decreased from 70 +/- 7 to 55 +/- 4 mm Hg after intravenous administration of dipyridamole. In the left anterior descending perfusion zone, the endocardial/epicardial flow ratio decreased from 0.70 to 0.36 and the intrinsic thallium washout rate was significantly prolonged. Intravenous aminophylline reversed the dipyridamole-induced systemic hypotension and transmural coronary steal and restored the thallium washout rate to baseline values. In six other dogs, aminophylline alone resulted in no alterations in systemic and coronary hemodynamics or regional myocardial blood flow. As expected, dipyridamole-induced vasodilation and coronary steal were prevented by aminophylline pretreatment. These data show that in a canine model of partial coronary stenosis, systemic hypotension, adverse regional flow effects and prolonged thallium-201 washout consequent to intravenously administered dipyridamole are promptly reversed by intravenous aminophylline administration. Aminophylline alone had no significant hemodynamic and coronary flow effects. This study provides further insight into the altered thallium kinetics occurring as a consequence of dipyridamole-induced vasodilation and suggests that the prompt reversal of symptoms and signs of ischemia with aminophylline in patients receiving intravenous dipyridamole for clinical imaging studies probably reflects the reversal of transmural coronary steal

False-negative dipyridamole-thallium-201 myocardial imaging after caffeine infusion

International Nuclear Information System (INIS)

Smits, P.; Corstens, F.H.; Aengevaeren, W.R.; Wackers, F.J.; Thien, T.

1991-01-01

The vasodilator effect of intravenously administered dipyridamole may be caused by an increase in endogenous plasma adenosine levels. The authors evaluated the effect of caffeine, an adenosine receptor antagonist, on the diagnostic results of dipyridamole-201Tl myocardial imaging in eight patients with coronary artery disease. Caffeine infusion significantly attenuated the dipyridamole-induced fall in blood pressure and the accompanied increase in heart rate. The infusion of dipyridamole alone resulted in chest pain and ST-segment depressions on the electrocardiogram in four patients, whereas none of these problems occurred when the tests were repeated after caffeine. In six of eight patients, caffeine was responsible for false-negative dipyridamole-201Tl tests. Semiquantitive scores of the dipyridamole-induced 201Tl perfusion defects were decreased by caffeine from 9.0 ± 0.9 to 2.0 ± 1.1 points (p less than 0.05). Computerized analysis revealed a caffeine-mediated reduction in the percent reversibility of the images from 46% ± 16% to 6% ± 10% (p less than 0.05). They conclude that the use of caffeinated products prior to dipyridamole-201Tl testing may be responsible for false-negative findings

False-negative dipyridamole-thallium-201 myocardial imaging after caffeine infusion

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Smits, P.; Corstens, F.H.; Aengevaeren, W.R.; Wackers, F.J.; Thien, T. (University Hospital Nijmegen (Netherlands))

1991-08-01

The vasodilator effect of intravenously administered dipyridamole may be caused by an increase in endogenous plasma adenosine levels. The authors evaluated the effect of caffeine, an adenosine receptor antagonist, on the diagnostic results of dipyridamole-201Tl myocardial imaging in eight patients with coronary artery disease. Caffeine infusion significantly attenuated the dipyridamole-induced fall in blood pressure and the accompanied increase in heart rate. The infusion of dipyridamole alone resulted in chest pain and ST-segment depressions on the electrocardiogram in four patients, whereas none of these problems occurred when the tests were repeated after caffeine. In six of eight patients, caffeine was responsible for false-negative dipyridamole-201Tl tests. Semiquantitive scores of the dipyridamole-induced 201Tl perfusion defects were decreased by caffeine from 9.0 {plus minus} 0.9 to 2.0 {plus minus} 1.1 points (p less than 0.05). Computerized analysis revealed a caffeine-mediated reduction in the percent reversibility of the images from 46% {plus minus} 16% to 6% {plus minus} 10% (p less than 0.05). They conclude that the use of caffeinated products prior to dipyridamole-201Tl testing may be responsible for false-negative findings.

Predictive value of quantitative dipyridamole-thallium scintigraphy in assessing cardiovascular risk after vascular surgery in diabetes mellitus

International Nuclear Information System (INIS)

Lane, S.E.; Lewis, S.M.; Pippin, J.J.; Kosinski, E.J.; Campbell, D.; Nesto, R.W.; Hill, T.

1989-01-01

Cardiac complications represent a major risk to patients undergoing vascular surgery. Diabetic patients may be particularly prone to such complications due to the high incidence of concomitant coronary artery disease, the severity of which may be clinically unrecognized. Attempts to stratify groups by clinical criteria have been useful but lack the predictive value of currently used noninvasive techniques such as dipyridamole-thallium scintigraphy. One hundred one diabetic patients were evaluated with dipyridamole-thallium scintigraphy before undergoing vascular surgery. The incidence of thallium abnormalities was high (80%) and did not correlate with clinical markers of coronary disease. Even in a subgroup of patients with no overt clinical evidence of underlying heart disease, thallium abnormalities were present in 59%. Cardiovascular complications, however, occurred in only 11% of all patients. Statistically significant prediction of risk was not achieved with simple assessment of thallium results as normal or abnormal. Quantification of total number of reversible defects, as well as assessment of ischemia in the distribution of the left anterior descending coronary artery was required for optimum predictive accuracy. The prevalence of dipyridamole-thallium abnormalities in a diabetic population is much higher than that reported in nondiabetic patients and cannot be predicted by usual clinical indicators of heart disease. In addition, cardiovascular risk of vascular surgery can be optimally assessed by quantitative analysis of dipyridamole-thallium scintigraphy and identification of high- and low-risk subgroups

Intravenous dipyridamole thallium-201 SPECT imaging methodology, applications, and interpretations

International Nuclear Information System (INIS)

Rockett, J.F.; Magill, H.L.; Loveless, V.S.; Murray, G.L.

1990-01-01

Dipyridamole TI-201 imaging is an ideal alternative to exercise TI-201 scintigraphy in patients who are unwilling or unable to perform maximum exercise stress. The use of intravenous dipyridamole, alone or in combination with exercise, has not been approved for clinical practice by the Food and Drug Administration. Once approval is granted, the test will become a widely used and important component of the cardiac work-up. The indications, methodology, side effects, and utility of dipyridamole cardiac imaging in the clinical setting are discussed and a variety of examples presented.59 references

Significance of increased lung thallium-201 activity on serial cardiac images after dipyridamole treatment in coronary heart disease

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Okada, R.D.; Dai, Y.H.; Boucher, C.A.; Pohost, G.M.

1984-01-01

Increased lung thallium-201 (Tl-201) activity occurs in patients with severe coronary artery disease (CAD) on initial postexercise images. To determine the significance of assessing lung Tl-201 on serial imaging after dipyridamole therapy, initial and delayed (2 to 3 hours) Tl-201 imaging was performed in 40 patients with CAD and 26 normal control subjects. Lung Tl-201 activity was quantitated as a percentage of maximal myocardial activity for each imaging time (lung Tl-201 index). The mean initial lung Tl-201 activity was 42 +/- 2% (+/- standard error of the mean) in 26 control subjects, 56 +/- 2% in 25 patients with 2- or 3-vessel CAD (p less than 0.001) and 53 +/- 2% in 15 patients with 1-vessel CAD (p less than 0.005 compared with control subjects) (difference not significant between 1-vessel and multivessel CAD). Dipyridamole lung Tl-201 activity decreased relative to the myocardium from initial to delayed images (p less than 0.001) in patients with CAD but not in control subjects. When a dipyridamole lung Tl-201 index of 58% (mean +/- 2 standard deviations for control subjects) was chosen as the upper limit of normal, 14 of 40 of the CAD patients (35%) had abnormal values and all control patients had values within normal limits. These 14 patients with CAD and abnormal initial lung Tl-201 indexes had rest ejection fractions that were not significantly different from those in patients with CAD, and normal initial dipyridamole lung Tl-201 index (58 +/- 4% and 63 +/- 2%, respectively)

Exercise supplementation of dipyridamole for myocardial perfusion imaging

International Nuclear Information System (INIS)

DePuey, E.G.

1991-01-01

The substitution of intravenous dipyridamole for symptom-limited treadmill exercise has provided a non-invasive means to diagnose coronary artery disease with 201Tl scintigraphy in patients unable to adequately exercise. Limitations of dipyridamole/thallium imaging are primarily due to suboptimal image quality secondary to hepatic tracer concentration and decreased test sensitivity in patients who are dipyridamole non-responders. Low-level treadmill exercise supplementation improves image quality, whereas handgrip has little, if any, benefit. The effect of low-level exercise in augmenting coronary blood flow is unknown and reports regarding the effect of handgrip are conflicting. The diagnostic benefit of these maneuvers in improving test sensitivity and decreasing the number of non-responders has not been documented. The combination of maximal, symptom-limited treadmill exercise and intravenous dipyridamole is a theoretically attractive option to improve overall test sensitivity, but the physiologic consequences and potential side effects should be more thoroughly investigated

Dipyridamole-thallium-201 scintigraphy in the prediction of future cardiac events after acute myocardial infarction

International Nuclear Information System (INIS)

Leppo, J.A.; O'Brien, J.; Rothendler, J.A.; Getchell, J.D.; Lee, V.W.

1984-01-01

To evaluate the safety and usefulness of serial thallium scanning immediately after intravenous dipyridamole, we studied 51 patients recovering from acute myocardial infarction. Eight patients experienced angina during the procedure, but there were no serious complications. Patients were followed for a mean period of 19 months after hospital discharge. Eleven of 12 patients who died during follow-up or had another infarction had shown transient defects (redistribution) on their predischarge scan, as had 22 of the 24 patients who needed readmission for management of angina. Among all the other clinical or scintigraphic criteria tested, the presence of redistribution on the dipyridamole-thallium scan was the only significant predictor of these serious cardiac events. Twenty-six patients were also given a submaximal exercise test before discharge, of whom 13 subsequently had serious cardiac events. The exercise test had been positive in only 6 of these 13 patients, whereas the dipyridamole-thallium scan had shown a redistribution pattern in 12 (P less than 0.001). We conclude from this preliminary study that dipyridamole-thallium scintigraphy after myocardial infraction is relatively safe. It appears to be a more sensitive predictor of subsequent cardiac events than a submaximal exercise test and may therefore prove useful in evaluating patients after recovery from a myocardial infarction

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

International Nuclear Information System (INIS)

Perin, E.C.; Moore, W.; Blume, M.; Hernandez, G.; Dhekne, R.; DeCastro, C.M.

1991-01-01

After an intravenous infusion of dipyridamole (0.56 mg/kg), the authors 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, they 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

Usefulness of dipyridamole stress myocardial imaging in patients who have exercise limitations due to various orthopedic disorders

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Tagawa, Hirofumi; Ashihara, Toshiaki; Fukuyama, Takaya; Matsui, Kanji; Yamamoto, Sumiki; Yamamoto, Susumu

1994-01-01

To evaluate the presence of coronary artery disease in patients unable to exercise adequately because of chronic rheumatoid arthritis, osteoarthritis, hip bone fractures or disk herniation, we performed dipyridamole-stress thallium-201 myocardial imaging in thirty-three patients. Twelve of the 33 patients showed perfusion defect and redistribution by thallium imaging. Coronary angiography was performed in 9 patients out of these 12 dipyridamole-positive patients and significant coronary artery stenosis was detected in 7 of them (78%). Due to these results of dipyridamole-imaging and coronary angiograms, surgical intervention for the underlying bone or joint disorder was performed under cardioprotective strategy in 15 patients, in which no cardiovascular events occurred. Thus, dipyridamole-stress myocardial imaging is a satisfactory alternative to the exercise test for detecting coronary artery disease in patients with bone or joint disorders. (author)

Preoperative evaluation of cardiac risk using dobutamine-thallium imaging in vascular surgery

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Zellner, J.L.; Elliott, B.M.; Robison, J.G.; Hendrix, G.H.; Spicer, K.M.

1990-01-01

Coronary artery disease is frequently present in patients undergoing evaluation for reconstructive peripheral vascular surgery. Dobutamine-thallium imaging has been shown to be a reliable and sensitive noninvasive method for the detection of significant coronary artery disease. Eighty-seven candidates for vascular reconstruction underwent dobutamine-thallium imaging. Forty-eight patients had an abnormal dobutamine-thallium scan. Twenty-two patients had infarct only, while 26 had reversible ischemia demonstrated on dobutamine-thallium imaging. Fourteen of 26 patients with reversible ischemia underwent cardiac catheterization and 11 showed significant coronary artery disease. Seven patients underwent preoperative coronary bypass grafting or angioplasty. There were no postoperative myocardial events in this group. Three patients were denied surgery on the basis of unreconstructible coronary artery disease, and one patient refused further intervention. Ten patients with reversible myocardial ischemia on dobutamine-thallium imaging underwent vascular surgical reconstruction without coronary revascularization and suffered a 40% incidence of postoperative myocardial ischemic events. Five patients were denied surgery because of presumed significant coronary artery disease on the basis of the dobutamine-thallium imaging and clinical evaluation alone. Thirty-nine patients with normal dobutamine-thallium scans underwent vascular reconstructive surgery with a 5% incidence of postoperative myocardial ischemia. Dobutamine-thallium imaging is a sensitive and reliable screening method which identifies those patients with coronary artery disease who are at high risk for perioperative myocardial ischemia following peripheral vascular surgery

The incidence of serious hemodynamic changes in physically-limited patients following oral dipyridamole challenge before thallium-201 scintigraphy

International Nuclear Information System (INIS)

Kahn, D.; Argenyi, E.A.; Berbaum, K.; Rezai, K.

1990-01-01

Dipyridamole has liberalized referrals for stress TI-201 chloride (thallium) studies at the Iowa City Veterans Administration Medical Center. Seventy-five percent of referrals now receive dipyridamole and, unlike patients who tolerate conventional exercise testing, these patients are often quite debilitated. Therefore, the hemodynamic consequences of dipyridamole were reviewed in 120 consecutive, physically-limited patients referred for thallium scintigraphy following an average oral dose of 5.4 mg/kg. Each patient's blood pressure was measured every 5 minutes for 1 hour after dipyridamole and compared with several clinical factors to determine if blood pressure change was predictable. In all patients, blood pressure changed from 136 +/- 21/83 +/- 15 (mean +/- 1 SD) to 117 +/- 25/72 +/- 15 following dipyridamole administration. One hundred nine of the 120 patients had a blood pressure decline from 137 +/- 21/82 +/- 12 to 113 +/- 21/70 +/- 13. Of the 109, 43% (N = 47) had a systolic blood pressure decline greater than 20 mmHg, 16% (n = 18) greater than 40 mmHg, and 13% (n = 14) greater than 50 mmHg. Thirteen percent (n = 14) required emergent reversal of the dipyridamole with aminophylline. Significant hypotension is relatively common but generally unpredictable after oral dipyridamole. Therefore, patient eligibility criteria should be carefully considered; strict hemodynamic monitoring must be routine in the usual patient undergoing thallium scintigraphy after oral dipyridamole challenge

Dipyridamole thallium-201 single-photon emission tomography in aortic stenosis: gender differences

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Rask, L.P.; Karp, K.H.; Eriksson, N.P.; Mooe, T.

1995-01-01

This study was undertaken to establish the gender-specific normal limits of thallium-201 distribution in patients with aortic stenosis and to apply these normal limits in a larger group of patients with aortic stenosis to obtain the sensitivity and specificity for coexisting CAD. A low-dose dipyridamole protocol was used (0.56 mg/kg during 4 min). Thallium was injected 2 min later and tomographic imaging was performed. Following image reconstruction a basal, a mid-ventricular and an apical short-axis slice were selected. The highest activity in each 6 segment was normalised to the maximal activity of each slice. The normal uptake for patients with aortic stenosis was obtained from ten men and ten women with aortic stenosis and a normal coronary angiography. Eighty-nine patients were prospectively evaluated. An area reduction of at least 75% in a coronary artery was considered to be a significant coronary lesion and was found in 57 (64%) patients. With gender-specific curves (-2.5 SD) sensitivity for detecting CAD was 100% and specificity was 75% in men, while sensitivity was 61% and specificity 64% in women. It is concluded that the gender-specific normal distribution of 201 Tl uptake in patients with aortic stenosis, using dipyridamole SPET, yields a high sensitivity and specificity for coronary artery lesions in men but a lower sensitivity and specificity in women with aortic stenosis. (orig./MG)

Prognostic value of intravenous dipyridamole thallium scintigraphy after an acute myocardial ischemic event

International Nuclear Information System (INIS)

Younis, L.T.; Byers, S.; Shaw, L.; Barth, G.; Goodgold, H.; Chaitman, B.R.

1989-01-01

Seventy-seven patients recovering from an acute coronary event were studied by intravenous dipyridamole thallium scintigraphy to evaluate the prognostic value and safety of the test in this patient subset. Forty-four patients (58%) had unstable angina and 33 (42%) had an acute myocardial infarction. One death occurred within 24 hours of testing. Sixty-eight patients were followed for an average of 12 months; 25, 31 and 23% had a fixed, reversible or combined thallium defect on their predischarge thallium scan. During follow-up, 10 patients died or had a nonfatal myocardial infarction; in each case, a reversible or combined myocardial thallium defect was present. Univariate analysis of 17 clinical, scintigraphic and angiographic variables showed that a reversible thallium defect and the angiographically determined extent of coronary artery disease were predictors of future cardiac events. The extent of coronary disease and global left ventricular ejection fraction were predictors of subsequent reinfarction or death. Logistic regression analyses revealed that a reversible thallium defect (p less than 0.001) and the extent of coronary disease (p less than 0.009) were the only significant predictors of a cardiac event. When death or reinfarction were the outcome variables, the extent of coronary disease (p less than 0.02) and left ventricular ejection fraction (p less than 0.06) were the only variables selected. Thus, intravenous dipyridamole thallium scintigraphy after an acute coronary ischemic syndrome is a useful and relatively safe noninvasive test to predict subsequent cardiac events

Significance of dipyridamole-induced transient dilation of the left ventricle during thallium-201 scintigraphy in suspected coronary artery disease

International Nuclear Information System (INIS)

Chouraqui, P.; Rodrigues, E.A.; Berman, D.S.; Maddahi, J.

1990-01-01

The occurrence and significance of transient dilation of the left ventricle during dipyridamole stress-redistribution thallium-201 scintigraphy was studied in 73 patients who underwent both dipyridamole thallium-201 study and coronary angiography. Transient dilation ratio was calculated from planar anterior images by dividing the computer-derived left ventricular area on the initial image by that of the 4-hour image. In 11 patients with normal coronary arteriograms or less than 50% coronary stenosis, the transient dilation ratio was 0.98 +/- 0.046. An abnormal transient dilation ratio was defined as greater than or equal to 1.12, representing greater than or equal to 3 standard deviations above the mean normal value. When the 15 patients with an abnormal ratio were compared with the 58 with a normal ratio, the former group had a significantly higher frequency of 3 critical (greater than or equal to 90%) coronary stenoses (33 vs 5%), higher prevalence of collaterals (67 vs 24%), more extensive myocardial reversible defects by planar (71 vs 10%) or by single-photon emission computed tomography (87.5 vs 35%) imaging and a higher incidence of dipyridamole-induced anginal chest pain (53 vs 22%). No significant difference between the 2 groups was noted with respect to age, gender, prior myocardial infarction, single or double critical coronary stenosis, dipyridamole-induced ischemic electrocardiographic response and increased lung uptake. An abnormal transient dilation ratio of greater than or equal to 1.12 was a specific marker of multivessel (87%) or 3-vessel (85%) critical coronary artery disease

Dipyridamole thallium-201 single-photon emission tomography in aortic stenosis: gender differences

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Rask, L P [Dept. of Clinical Physiology, Univ. Hospital of Northern Sweden, Umeaa (Sweden); [Dept. of Cardiology, Univ. Hospital of Northern Sweden, Umeaa (Sweden); Karp, K H [Dept. of Clinical Physiology, Univ. Hospital of Northern Sweden, Umeaa (Sweden); Eriksson, N P [Dept. of Radiology, Univ. Hospital of Northern Sweden, Umeaa (Spain); [Dept. of Cardiology, Univ. Hospital of Northern Sweden, Umeaa (Sweden); Mooe, T [Dept. of Cardiology, Univ. Hospital of Northern Sweden, Umeaa (Sweden)

1995-10-01

This study was undertaken to establish the gender-specific normal limits of thallium-201 distribution in patients with aortic stenosis and to apply these normal limits in a larger group of patients with aortic stenosis to obtain the sensitivity and specificity for coexisting CAD. A low-dose dipyridamole protocol was used (0.56 mg/kg during 4 min). Thallium was injected 2 min later and tomographic imaging was performed. Following image reconstruction a basal, a mid-ventricular and an apical short-axis slice were selected. The highest activity in each 6 segment was normalised to the maximal activity of each slice. The normal uptake for patients with aortic stenosis was obtained from ten men and ten women with aortic stenosis and a normal coronary angiography. Eighty-nine patients were prospectively evaluated. An area reduction of at least 75% in a coronary artery was considered to be a significant coronary lesion and was found in 57 (64%) patients. With gender-specific curves (-2.5 SD) sensitivity for detecting CAD was 100% and specificity was 75% in men, while sensitivity was 61% and specificity 64% in women. It is concluded that the gender-specific normal distribution of {sup 201}Tl uptake in patients with aortic stenosis, using dipyridamole SPET, yields a high sensitivity and specificity for coronary artery lesions in men but a lower sensitivity and specificity in women with aortic stenosis. (orig./MG)

Comparison of early exercise treadmill test and oral dipyridamole thallium-201 tomography for the identification of jeopardized myocardium in patients receiving thrombolytic therapy for acute Q-wave myocardial infarction

International Nuclear Information System (INIS)

Jain, A.; Hicks, R.R.; Frantz, D.M.; Myers, G.H.; Rowe, M.W.

1990-01-01

Thrombolytic therapy has become the treatment of choice for patients with acute myocardial infarction. Researchers are not yet able to identify patients with salvage of myocardium who are at risk for recurrent coronary events. Thus, a prospective trial was performed in 46 patients with myocardial infarction (28 anterior and 18 inferior) who received thrombolytic therapy to determine if early thallium tomography (4.7 days) using oral dipyridamole would identify more patients with residual ischemia than early symptom-limited exercise treadmill tests (5.5 days). There were no complications during the exercise treadmill tests or oral dipyridamole thallium tomography. Mean duration of exercise was 11 +/- 3 minutes and the peak heart rate was 126 beats/min. Thirteen patients had positive test results. After oral dipyridamole all patients had abnormal thallium uptake on the early images. Positive scans with partial filling in of the initial perfusion defects were evident in 34 patients. Angina developed in 13 patients and was easily reversed with intravenous aminophylline. Both symptom-limited exercise treadmill tests and thallium tomography using oral dipyridamole were safely performed early after myocardial infarction in patients receiving thrombolytic therapy. Thallium tomography identified more patients with residual ischemia than exercise treadmill tests (74 vs 28%). Further studies are required to determine whether the results of thallium tomography after oral dipyridamole can be used to optimize patient management and eliminate the need for coronary angiography in some patients

Relationship between regional myocardial blood flow and thallium-201 distribution in the presence of coronary artery stenosis and dipyridamole-induced vasodilation

International Nuclear Information System (INIS)

Mays, A.E. Jr.; Cobb, F.R.

1984-01-01

This study assesses the relationship between the distribution of thallium-201 and myocardial blood flow during coronary vasodilation induced by intravenous dipyridamole in canine models of partial and complete coronary artery stenosis. 10 dogs were chronically instrumented with catheters in the left atrium and aorta and with a balloon occluder and electromagnetic flow probe on the proximal left circumflex coronary artery. Regional myocardial blood flow was measured during control conditions with radioisotope-labeled microspheres, and the phasic reactive hyperemic response to a 20-s transient occlusion was then recorded. Dipyridamole was then infused intravenously until phasic coronary blood flow increased to match peak hyperemic values. The left circumflex coronary artery was either partially occluded to reduce phasic blood flow to control values (group 1) or it was completely occluded (group 2), and thallium-201 and a second microsphere label were injected. 5 min later, the animals were sacrificed, the left ventricle was sectioned into 1-2-g samples, and thallium-201 activity and regional myocardial blood flow were measured. Curvilinear regression analyses between thallium-201 localization and myocardial blood flow during dipyridamole infusion demonstrated a slightly better fit to a second- as compared with a first-order model, indicating a slight roll-off of thallium activity as myocardial blood flow increases. During the dipyridamole infusion, the increases in phasic blood flow, the distributions of regional myocardial blood flow, and the relationships between thallium-201 localization and regional blood flow were comparable to values previously observed in exercising dogs with similar occlusions. These data provide basic validation that supports the use of intravenous dipyridamole and thallium-201 as an alternative to exercise stress and thallium-201 for evaluating the effects of coronary occlusive lesions on the distribution of regional myocardial blood flow

Prognostic utility of intravenous dipyridamole thallium-201 imaging and exercise testing after an acute infarction

International Nuclear Information System (INIS)

Leppo, J.A.

1984-01-01

To define the prognosis in asymptomatic survivors of acute infarcts (MI), coronary vasodilation was induced with I.V. dipyridamole, followed by Thallium-201 (T1) imaging in 26 patients just prior to discharge. All patients (pts) also had a modified exercise treadmill (MET) test. During the imaging protocol, 10 (39%) pts experienced transient adverse effects and 12 (46%) pts had either angina or ST depression with MET. During a mean follow-up of 17 months, 13 (50%) pts had a cardiac event defined as readmission for control of angina, MI or death. In the 13 pts having cardiac events, 4 (31%) had ST depression and 2 (15%) had angina during MET, but 12 (92%) demonstrated T1 redistribution (RD) as determined by at least 1 segment/scan having a transient defect. A logistic regression analysis using several exercise, scintigraphic and general clinical parameters, showed that the presence of T1 RD was the only significant (p <0.001) predictor for future cardiac events. The predicted probability for events in pts with T1 RD was 80 +- 10% (SD) and was 9 +- 9% in those without T1 RD. The mean number of defects per scan was similar in pts with and without cardiac events, but compared to persistent defects, transient ones are associated with potentially ischemic myocardium. Although the pt population is relatively small, dipyridamole T1 imaging after MI appears to be safe and has demonstrated prognostic value. It also offers an alternative and/or addition to exercise testing in the predischarge evaluation after acute MI

Intrinsic washout rates of thallium-201 in normal and ischemic myocardium after dipyridamole-induced vasodilation

International Nuclear Information System (INIS)

Beller, G.A.; Holzgrefe, H.H.; Watson, D.D.

1985-01-01

Infusion of dipyridamole has been suggested as an alternative to exercise stress for myocardial perfusion imaging for detection of ischemia, but the mechanism and significance of thallium-201 ( 201 Tl) redistribution after administration of dipyridamole are uncertain. If disparate intrinsic cellular efflux rates of 201 Tl from normal and relatively underperfused myocardium in response to dipyridamole-induced vasodilation were observed, this could explain delayed 201 Tl redistribution. We investigated the effect of an intravenous infusion of 0.15 mg/kg dipyridamole on the intrinsic myocardial washout rate of 201 Tl as measured with a gamma-detector probe after intracoronary injection (50 muCi) of the radionuclide in open-chested anesthetized dogs. In six normal dogs the t 1/2 for intrinsic 201 Tl washout from the myocardium was 89 +/- 11 min (SE) at control conditions and became more rapid at 59 +/- 10 min (p . .0001) after dipyridamole. This corresponded to a significant increase in microsphere-determined epicardial (0.95 +/- 0.11 to 2.23 +/- 0.46 ml/min/g; p . .01) and endocardial (0.86 +/- 0.10 to 1.53 +/- 0.27; p . .029) flows. In 12 dogs with a critical coronary stenosis, the 201 Tl intrinsic washout rate slowed from 70 +/- 5 to 104 +/- 6 min (p . .0001) after production of the stenosis and slowed even further to 169 +/- 21 min (p . .003) after dipyridamole

Intravenous dipyridamole thallium-201 SPECT imaging in patients with left bundle branch block

International Nuclear Information System (INIS)

Rockett, J.F.; Wood, W.C.; Moinuddin, M.; Loveless, V.; Parrish, B.

1990-01-01

Tl-201 exercise imaging in patients with left bundle branch block (LBBB) has proven to be indeterminate for significant left anterior descending (LAD) coronary artery stenosis because of the presence of immediate septal perfusion defects with redistribution on delayed images in almost all cases. Tl-201 redistribution occurs regardless of the presence or absence of LAD stenosis. Nineteen patients having LBBB were evaluated with dipyridamole Tl-201 SPECT. Fourteen of these subjects had normal dipyridamole Tl-201 SPECT imaging. Three patients had normal coronary angiograms. None of the remaining 11 patients with normal dipyridamole Tl-201 SPECT images was found to have clinical coronary artery disease in a 5-11 month follow-up period. Five patients had abnormal septal perfusion. Four underwent coronary angiography. One had a significant LAD stenosis. The single patient with septal redistribution who refused to undergo coronary angiography died shortly thereafter of clinical coronary artery disease. This preliminary work suggests that dipyridamole Tl-201 SPECT may be more useful for excluding LAD stenosis in patients with LBBB than Tl-201 exercise imaging

Myocardial thallium scintigraphy after dipyridamole injection. Application to the diagnosis and evaluation of coronary disease

International Nuclear Information System (INIS)

Foult, J.M.; Weinmann, P.; Moretti, J.L.; Le Guludec, D.; Faraggi, M.

1992-01-01

Myocardial thallium scintigraphy performed after intravenous injection of dipyridamole is a non-invasive method to diagnose and evaluate coronary disease.It be used as an alternative to post-exercise scintigraphy, both methods having similar sensitivity and specificity. The dipyridamole test is contraindicated in patients with a history of bronchospasm and uncontrolled angina pectoris. Close clinical and electrocardiographic monitoring is required. The wide use of tomographic techniques has notably improved this examination

Biphasic 201thallium scintgraphy after dipyridamole in mitral valve diseases

International Nuclear Information System (INIS)

Schmoliner, R.; Dudczak, R.; Kronik, G.; Moesslacher, H.; Kletter, K.; Frischauf, H.

1980-01-01

The results of biphasic 201 thallium scintigraphy after dipyridamole i.v. could neither prove nor exclude the presence of small focal lesions in the myocardium of 17 patients with mitral valve diseases. The frequent finding of a decrease in activity in the anterolateral myocardium is probably due to a relative increase in activity in the region of the inferior wall with superimposed areas of the papillary muscle and right ventricular myocardium. If the right ventricle is visualized in stress- or redistribution images, an increase in mean pulmonary artery pressure can be accepted. According to Cohen's criteria, a grade 2 or 3 virtually proves the existence of pulmonary hypertension, a grade 1 makes this finding rather probable. The possibility of pulmonary hypertension can not be excluded if the right ventricular myocardium is not visualized. (orig.) [de

The clinical value of chest pain during thallium-201 scintigraphy with dipyridamole

International Nuclear Information System (INIS)

Takeishi, Yasuchika; Tono-oka, Ichiro; Meguro, Mitsuhiko; Hoshi, Hikaru; Yamaguchi, Yoshiko; Masakane, Ikuto; Tsuiki, Kai; Yasui, Shoji

1990-01-01

Sixty patients with suspected coronary artery disease underwent both dipyridamole-loaded thallium-201 scintigraphy and cardiac catheterization. Thirty four patients (57%) developed chest pain during dipyridamole stress testing (the pain group), and the other 26 did not (the no-pain group). Regarding sex, age, history of myocardial infarction, and the presence of coronary artery disease, there was no difference between the pain and no-pain groups. The pain group had significantly increased pulse rate and rate-pressure-product, as compared with the no-pain group. ST depression was more frequently observed in the pain group than the no-pain group. There was no significant difference in the angiographic involvement and the severity of coronary artery disease between the two groups. Nor was there significant difference in dipyridamole-loaded scintigraphic findings, such as defect size, and the extent and degree of decreased washout. However, for patients without a history of myocardial infarction, the pain group had a farther decreased washout than the no-pain group. Chest pain associated with iv injection of dipyridamole may have implications for the occurrence of serious ischemia. (N.K.)

Noninvasive identification of left main and triple vessel coronary artery disease using dipyridamole thallium scintigraphy

International Nuclear Information System (INIS)

Chikamori, Taishiro; Doi, Yoshinori; Yonezawa, Yoshihiro; Yamada, Mitsutoshi; Seo, Hiromi; Kawai, Kazuya; Yabe, Toshikazu; Ozawa, Toshio

1993-01-01

The diagnostic value of dipyridamole thallium scintigraphy for the noninvasive identification of left main (LM) and triple vessel (TV) coronary artery disease (CAD) was evaluated in 615 consecutive patients with known or suspected CAD. One hundred thirty-nine patients had LM or TVCAD; the remaining 476 patients had limited CAD (double vessel CAD in 112, single vessel CAD in 235, insignificant lesions in 129). Patients with LM or TVCAD, compared to those with limited CAD, had a higher incidence of diffuse slow washout (58 vs 20%, p<0.0001), extensive fixed defects (21 vs 6%, p<0.0001) and extensive reversible defects (32 vs 8%, p<0.0001). During dipyridamole loading, the incidence of chest pain was higher (65 vs 41%, p<0.0001), and the magnitude of ST depression was greater (0.16±0.14 vs 0.04±0.07 mV, p<0.001) in patients with LM or TVCAD than in those with limited CAD. Stepwise discriminant analysis using scintigraphic imaging achieved a sensitivity of 69%, a specificity of 79%, and an accuracy of 77% for diagnosing patients with LM or TVCAD. After including clinical markers of ischemia during dipyridamole loading, multivariate analysis revealed an improved diagnosis with a sensitivity of 71%, a specificity of 85%, and an accuracy of 82%. These results clearly show the usefulness of scintigraphic imaging as well as the significance of careful assessment of clinical markers of ischemia during dipyridamole loading for the noninvasive identification of LM and TVCAD. (author)

Effects of dipyridamole-induced vasodilation on myocardial uptake and clearance kinetics of thallium-201

International Nuclear Information System (INIS)

Beller, G.A.; Holzgrefe, H.H.; Watson, D.D.

1983-01-01

Myocardial thallium-201 (201Tl) uptake and clearance after intravenous administration of dipyridamole (150 micrograms/kg) were determined in 12 open-chest anesthetized dogs with a partial coronary artery stenosis. 201Tl (1.5 mCi) was injected intravenously and myocardial biopsy specimens were obtained 10 min, 60 min, and 2 hr after injection. Serial changes in 201Tl activity in the normal zone and in the zone of partial stenosis were correlated with microsphere-determined regional blood flow and distal coronary pressure. Another nine dogs with equivalent stenosis not given dipyridamole before 201Tl served as controls. Data indicate that dipyridamole-induced vasodilation in the presence of a partial stenosis results in diminished uptake and delayed clearance compared with increased uptake and more rapid clearance in normally perfused myocardium producing an initial 201Tl defect with delayed redistribution

Dipyridamole thallium-201 single-photon emission computed tomography for prediction of perioperative cardiac events in patients with arteriosclerosis obliterans undergoing vascular surgery

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Ziyang, Huang; Komori, Sadayoshi; Sawanobori, Takao

1998-01-01

The aim of the study was to determine whether or not dipyridamole thallium-201 single-photon emission computed tomography ( 201 Tl-SPECT) has significant additive value for predicting perioperative cardiac events in patients with arteriosclerosis obliterans (ASO) undergoing vascular surgery. Routine preoperative 201 Tl-SPECT was performed in 106 consecutive patients with ASO (age 68±8.9 years; 91 men and 15 women). The frequency of reversible defects in a clinical high-risk group (n=44) was significantly higher than in a low-risk group (n=62; 55% vs 24%, p 201 Tl-SPECT data to clinical risk-stratified patients with ASO allows better prediction of perioperative cardiac events. (author)

Preoperative imaging in primary hyperparathyroidism. Role of thallium-technetium subtraction scintigraphy

International Nuclear Information System (INIS)

Foster, G.S.; Bekerman, C.; Blend, M.J.; Byrom, E.; Pinsky, S.M.

1989-01-01

Primary hyperparathyroidism, although often silent clinically, may lead to significant morbidity if it remains untreated. In more than 95% of all cases the cause is a parathyroid adenoma or glandular hyperplasia. Regression of disease follows successful surgical excision of the abnormal parathyroid gland. Recurrent or persistent hyperparathyroidism is most commonly caused by solitary adenomas, which may have an ectopic location. Preoperative localization of lesions may improve postoperative cure rates and decrease morbidity. Thallium T1 201 chloride-technetium Tc 99m pertechnetate subtraction scintigraphy was performed on 15 patients with primary hyperparathyroidism. The sensitivity and specificity for detection of abnormal glands were 90% and 95%, respectively. False-positive or false-negative results were minimize by strict adherence to a protocol and by the use of well-defined diagnostic criteria. Because of the superior sensitivity and specificity, this modality should be the primary imaging method of choice for preoperative evaluation of primary hyperparathyroidism. The relative role of other imaging modalities is also discussed. 31 references

Safety of intravenous dipyridamole thallium myocardial perfusion imaging: experience in 435 patients

International Nuclear Information System (INIS)

Dubrey, S.W.; Noble, M.I.M.; Jewkes, R.F.; Bomanji, J.B.

1993-01-01

Dipyridamole stress 201 T1 scintigraphy is widely used in the investigation of myocardial ischaemia. We report our experience of adverse effects observed during this diagnostic procedure. A prospective study was undertaken of 435 consecutive patients referred to two nuclear medicine departments for assessment of myocardial perfusion. Patients were monitored prior to and following the infusion of dipyridamole. All symptomatic, haemodynamic and electrocardiographic changes were documented. No deaths occurred in this series. Adverse events were observed in 174 (40%) patients. Of these, three patients experienced 'major' adverse events (0.6%) requiring hospitalization (myocardial infarction = 1; chest pain = 1; simple partial seizure = 1). 'Moderate' adverse events occurred in 39 (8.9%) patients and required intravenous aminophylline to reverse effects (ST segment abnormalities = 26; nausea = 7; headache = 3; chest pain = 2; bronchospasm = 1; protracted vomiting = 1; diarrhoea = 1). 'Minor' adverse events were experienced by 132 (30.3%) patients and did not require aminophylline. Sixty per cent of our patients experienced no ill effects from dipyridamole given as an exercise substitute in conjunction with 201 T1 imaging. The rest had symptoms which were mostly mild, although a few patients found the experience unpleasant. Only one patient experienced a life-threatening episode. (Author)

Comparison of coronary angiography and early oral dipyridamole thallium-201 scintigraphy in patients receiving thrombolytic therapy for acute myocardial infarction

International Nuclear Information System (INIS)

Jain, A.; Hicks, R.R.; Myers, G.H.; McCarthy, J.J.; Perry, J.R.; Adams, K.F.

1990-01-01

We evaluated 50 consecutive patients who received thrombolytic therapy for acute myocardial infarction using thallium-201 single photon emission computed tomography in combination with oral dipyridamole to assess the frequency of residual myocardial ischemia. Thallium studies were performed early after myocardial infarction at a mean of 4.6 days. The time from the onset of chest pain to the administration of thrombolytic therapy was 2.6 hours (range 0.5 to 5.5). Q wave myocardial infarction was evident in 46 patients; four patients had a non-Q wave infarction (anterior infarction in 31 patients and inferior infarction in 19 patients). The serum mean peak creatinine kinase was 1503 IU/L (range 127 to 6500). Coronary angiography was performed in all patients at a mean of 3.1 days (range 2 to 10) and revealed the infarct-related vessel to be patent in 36 patients (72%). The ejection fraction was 48% (range 26% to 67%). After dipyridamole administration, 13 patients (26%) developed angina that was easily reversed with the administration of intravenous aminophylline. Systolic blood pressure decreased from 122 to 115 mm Hg (p less than 0.05) and the heart rate increased from 76 to 85 beats/min (p less than 0.05). None of the patients had significant hypotension, arrhythmias, or evidence of infarct extension. Perfusion abnormalities were present on the initial thallium images in 48 patients. Redistribution suggestive of ischemia was present in 36 patients (72%). Ischemia confined to the vascular distribution of the infarct vessel was evident in 22 patients. Seven patients had ischemia in the infarct zone as well as in a remote myocardial segment. Thus 29 patients (58%) had ischemia in the distribution of the infarct vessel. Ischemia in the infarct zone was evident in 19 of 36 patients with open infarct vessels and in 10 of 14 patients with occluded infarct vessels

Serum caffeine levels after 24 hours of caffeine abstention: observations on clinical patients undergoing myocardial perfusion imaging with dipyridamole or adenosine

International Nuclear Information System (INIS)

Jacobson, A.F.; Cerqueira, M.D.; Raisys, V.; Shattuc, S.

1994-01-01

Although caffeine attenuates the vasodilatation produced by dipyridamole and adenosine, and is therefore contraindicated when these agents are used for myocardial perfusion scintigraphy, caffeine levels in clinical patients undergoing standard imaging protocols have not been studied. Eighty-six patients undergoing clinically indicated intravenous dipyridamole (n=75) or adenosine (n=11) thallium-201 myocardial perfusion scintigraphy, all of whom reported abstention from products containing caffeine for 24 h, were studied prospectively. Blood samples were drawn prior to initiation of the pharmacologic infusion, and serum caffeine levels were determined using an enzyme immunoassay technique. Results of these determinations were correlated with maximum pulse and blood pressure changes measured during and immediately after the stressor infusion, and thallium imaging findings. Detectable caffeine levels were found in 34 patients (40%), ranging from 0.1 to 5.0 mg/l. There was no significant difference in mean systolic blood pressure decrease or mean pulse increase between patients with caffeine levels > 1.0 mg/l (20.4 ± 18.2 mmHg, 11.0 ± 8.9 BPM; n=5) and those with lower (0.1 to 0.9 mg/l) (15.4 ± 9.5 mmHg, 14.4 ± 8.2 BPM; n=29) or no detectable caffeine levels (18.0 ± 11.5 mmHg, 16.6 ± 10.1 BPM; n=52). Redistribution on thallium imaging was also identified with a similar frequency in these three groups (2/5, 40%; 8/29, 28%; 22/52, 42% respectively). (orig.)

Serum caffeine levels after 24 hours of caffeine abstention: observations on clinical patients undergoing myocardial perfusion imaging with dipyridamole or adenosine

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Jacobson, A.F. (Nuclear Medicine Section, Dept. of Veterans Affairs Medical Center, Seattle, WA (United States) Univ. of Washington, Seattle, WA (United States)); Cerqueira, M.D. (Nuclear Medicine Section, Dept. of Veterans Affairs Medical Center, Seattle, WA (United States) Univ. of Washington, Seattle, WA (United States)); Raisys, V. (Dept. of Lab. Medicine, Harborview Medical Center, Seattle, WA (United States) Univ. of Washington, Seattle, WA (United States)); Shattuc, S. (Univ. of Washington, Seattle, WA (United States))

1994-01-01

Although caffeine attenuates the vasodilatation produced by dipyridamole and adenosine, and is therefore contraindicated when these agents are used for myocardial perfusion scintigraphy, caffeine levels in clinical patients undergoing standard imaging protocols have not been studied. Eighty-six patients undergoing clinically indicated intravenous dipyridamole (n=75) or adenosine (n=11) thallium-201 myocardial perfusion scintigraphy, all of whom reported abstention from products containing caffeine for 24 h, were studied prospectively. Blood samples were drawn prior to initiation of the pharmacologic infusion, and serum caffeine levels were determined using an enzyme immunoassay technique. Results of these determinations were correlated with maximum pulse and blood pressure changes measured during and immediately after the stressor infusion, and thallium imaging findings. Detectable caffeine levels were found in 34 patients (40%), ranging from 0.1 to 5.0 mg/l. There was no significant difference in mean systolic blood pressure decrease or mean pulse increase between patients with caffeine levels > 1.0 mg/l (20.4 [+-] 18.2 mmHg, 11.0 [+-] 8.9 BPM; n=5) and those with lower (0.1 to 0.9 mg/l) (15.4 [+-] 9.5 mmHg, 14.4 [+-] 8.2 BPM; n=29) or no detectable caffeine levels (18.0 [+-] 11.5 mmHg, 16.6 [+-] 10.1 BPM; n=52). Redistribution on thallium imaging was also identified with a similar frequency in these three groups (2/5, 40%; 8/29, 28%; 22/52, 42% respectively). (orig.)

Noninvasive identification of significant narrowing of the left main coronary artery by dipyridamole thallium scintigraphy

International Nuclear Information System (INIS)

Chikamori, T.; Doi, Y.L.; Yonezawa, Y.; Yamada, M.; Seo, H.; Ozawa, T.

1991-01-01

To evaluate the usefulness of dipyridamole thallium scintigraphy with low-level exercise for the identification of left main (LM) coronary artery disease (CAD), 466 consecutive patients with CAD were studied. Thirty-eight patients (8%) had LM stenosis (diameter narrowing greater than or equal to 50%). The LM scintigraphic pattern was present in 9 of 38 patients with LMCAD and 38 of 428 CAD patients without LMCAD (24 vs 9%; p less than 0.005). This pattern was present in 6 of 9 patients with LMCAD without right CAD and in only 3 of 29 patients with LM and right CAD (67 vs 10%; p = 0.0005). Patients with LMCAD had a higher incidence of premature cessation of low-level exercise (53 vs 21%; p less than 0.0001), chest pain (68 vs 48%; p less than 0.02), blood pressure decrease of greater than or equal to 20 mm Hg (44 vs 16%; p less than 0.002) and greater ST depression (0.17 ± 0.13 vs 0.06 ± 0.10 mV; p less than 0.001) during dipyridamole loading than patients without LMCAD. Stepwise discriminant analysis revealed that the LM scintigraphic pattern and markers of ischemia during dipyridamole loading best identified (p less than 0.0001) patients with LMCAD without right CAD (sensitivity 67%, specificity 91%), but this predictability is no better than the LM scintigraphic pattern alone. The combination of clinical markers of ischemia during dipyridamole loading and scintigraphic findings of diffuse slow washout, extensive fixed defects and the LM pattern best identified (p less than 0.0001) patients with LM and right CAD (sensitivity 72%, specificity 80%)

Biphasic thallium 201 SPECT-imaging for the noninvasive diagnosis of myocardial perfusion abnormalities in a child with Kawasaki disease--a case report

International Nuclear Information System (INIS)

Hausdorf, G.; Nienaber, C.A.; Spielman, R.P.

1988-01-01

The mucocutaneous lymph node syndrome (Kawasaki disease) is of increasing importance for the pediatric cardiologist, for coronary aneurysms with the potential of thrombosis and subsequent stenosis can develop in the course of the disease. The authors report a 2 1/2-year-old female child in whom, fourteen months after the acute phase of Kawasaki disease, myocardial infarction occurred. Biphasic thallium 201 SPECT-imaging using dipyridamole depicted anterior wall ischemia and inferolateral infarction. This case demonstrates that noninvasive vasodilation-redistribution thallium 201 SPECT-imaging has the potential to predict reversible myocardial perfusion defects and myocardial necrosis, even in small infants with Kawasaki disease

Reverse redistribution in dipyridamole-loading thallium-201 images using single photon emission computed tomography

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Mori, Kiyoo; Masuda, Masanosuke; Bunko, Hisashi.

1986-01-01

Dipyridamole was infused intravenously at a rate of 0.142 mg/kg per min for four min, and a stress image was obtained 10 min after the injection of two mCi 201 Tl. The myocardial image of Tl was analyzed by single photon emission computed tomography and its washout rate was calculated by the segmental ROI method. Myocardial function and the motion of the left ventricular wall were analyzed by 99m Tc-RBC-gated cardiac pool imaging. Reverse redistribution was noted in 27 (21.6 %) of 125 consecutive Tl dipyridamole and redistribution myocardial imaging studies. The stress image demonstrated normal perfusion (group 1) and reduced perfusion (group 2) of Tl. Group 1 consisted of 17 patients with diabetes mellitus, supraventricular arrhythmias, hypertension, and others. Group 2 consisted of 10 patients with subendocardial infarction, diabetes mellitus, and hypertension, and others. The percentage prevalence of reverse redistribution among patients with supraventricular arrhythmia was 62.5 % (five of eight patients), with subendocardial infarction 60.0 % (three of five), with hypertension 42.8 % (six of 14), and with diabetes mellitus 40.0 % (eight of 20), while in those with transmyocardial infarction and angina pectoris no reverse redistribution percentage was found. The washout rate of Tl in normal perfusion areas was 44.0 ± 12.8 %, the reverse redistribution of group 1 was 47.4 ± 12.8 %, and of group 2 was 51.2 ± 8.2 %. The washout rate of the reverse redistribution of group 2 was significantly greater than that of the normal areas. In gated cardiac pool imaging, patients in group 2 had significantly larger areas showing abnormal contraction of the left ventricular wall and significantly lower ejection fraction than did group 1. In the electrocardiogram ST segment depression was noted more frequently in group 2 than group 1. No Q wave was present in the corresponding reverse redistribution area. (J.P.N.)

The usefulness of dipyridamole thallium-201 single photon emission computed tomography for predicting perioperative cardiac events in patients undergoing non-cardiac vascular surgery

International Nuclear Information System (INIS)

Chen, Tao; Kuwabara, Yasuo; Tsutsui, Hiroyuki; Sasaki, Masayuki; Nakagawa, Makoto; Koga, Hirofumi; Kaneko, Kouichirou; Komori, Kimihiro; Masuda, Kouji

2002-01-01

The aim of this study was to evaluate the usefulness of dipyridamole Tl-201 myocardium single photon emission computed tomography ( 201 Tl-SPECT) for predicting perioperative cardiac events in patients with arteriosclerosis obliterans (ASO) and abdominal aortic aneurysm (AAA) undergoing non-cardiac vascular surgery. Preoperative dipyridamole 201 Tl-SPECT imaging in association with clinical risk assessment was performed in 224 consecutive patients (97 ASO and 127 AAA). The patients were classified into three groups, including low-risk (n=173, 77%), intermediate-risk (n=39, 18%), and high-risk (n=12, 5%) groups according to the clinical risk stratification. The prevalence of reversible Tl-201 defect was significantly higher in the high-risk group than that in the low-risk group (83% vs. 14%, p 201 Tl-SPECT was the only variable to predict perioperative cardiac events by a stepwise logistic regression analysis (odds ratio 7.0, 95% confidence interval 1.7-28.0, p=0.007). It was also a significant predictor of perioperative cardiac events in a subgroup of low risk patients (odds ratio 11.6, 95% confidence interval 2.3-57.4, p=0.004). The sensitivity and specificity of the reversible defect for predicting perioperative cardiac events were 55.6% and 84.8% in all operated patients, and 57.1% and 89.7% in low risk patients, respectively. The preoperative dipyridamole 201 Tl-SPECT was useful for predicting perioperative cardiac events in patients with vascular diseases, even in patients identified as having a low risk based on the clinical risk assessment. (author)

Tomographic thallium-201 myocardial perfusion scintigrams after maximal coronary artery vasodilation with intravenous dipyridamole: comparison of qualitative and quantitative approaches

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Francisco, D.A.; Collins, S.M.; Go, R.T.; Ehrhardt, J.C.; Van Kirk, O.C.; Marcus, M.L.

1982-01-01

Eighty-six patients had thallium-201 ( 201 Tl) myocardial perfusion scintigrams after intense coronary artery dilation with i.v. dipyridamole. Tomographic and planar 201 Tl scintigrams were obtained in each patient. Tomographic scintigrams were interpreted using quantitative or visual criteria; planar scintigrams were assessed using visual criteria only. When visual criteria were used, interobserver variability was 40% for tomographic scintigrams and 44% for planar scintigrams. In the 24 patients with normal or nonsignificant CAD, quantitative analysis of the tomograms (range approach) indicated that one of 24 (4%) had a positive image (specificity 96%%); in contrast, when visual criteria were used to interpret the tomographic or planar 201 Tl scintigrams, eight of 24 (33%) had positive scintigrams (specificity 67%). In the 51 abnormal patients, the sensitivity of detecting CAD was 46 of 51 (90%) for tomographic scintigrams interpreted quantitatively, 39 of 51 (76%) for tomographic scintigrams interpreted visually and 41 of 51 (80%) for planar scintigrams assessed visually. The tomographic imaging procedure (quantitative interpretation) also demonstrated a high sensitivity (89%) and specificity (100%) in 28 patients (10 normal and 18 CAD), with a clinical diagnosis of unstable angina pectoris. Overall, the predictive accuracy of an abnormal scintigram with quantitative tomographic imaging (98%) was significantly better (p<0.05) than either qualitative planar or pinhole imaging

Dipyridamole-thallium tests are predictive of severe cardiac arrhythmias in patients with left ventricular hypertrophy

International Nuclear Information System (INIS)

Saragoca, M.A.; Canziani, M.E.; Gil, M.A.; Castiglioni, M.L.; Cassiolato, J.L.; Barbieri, A.; Lima, V.C.; Draibe, S.A.; Martinez, E.E.

1991-01-01

In a population of patients with chronic renal failure (CRF) and a high prevalence of left ventricular hypertrophy (LVH) undergoing chronic hemodialysis, the authors investigated the association between the results of dipyridamole-thallium tests (DTTs) and the occurrence of ventricular arrhythmias. They observed a positive significant association between positive DTTs and the occurrence of severe forms of ventricular arrhythmias. A significant association was also observed between the presence of severe LVH and the occurrence of severe ventricular arrhythmias. However, no association was found between the presence of LVH and the positivity of the DTT. As most of their patients with positive DTTs had unimpaired coronary circulations, they conclude that positive DTTs, although falsely indicative of impaired myocardial blood supply, does have an important clinical relevance, indicating increased risk of morbidity (and, possibly, mortality) due to ventricular arrhythmias in a population of CRF patients submitted to chronic renal function replacement program

Diagnosis and prognosis of elderly patients with coronary artery disease. Assessment with dipyridamole thallium imaging

International Nuclear Information System (INIS)

Yamasaki, Fumiyasu; Takata, Jun; Seo, Hiromi; Chikamori, Taishiro; Yamada, Mitsutoshi; Yabe, Toshikazu; Doi, Yoshinori

1995-01-01

The diagnostic and prognostic value of dipyridamole perfusion scintigraphy was assessed in 147 patients with coronary artery disease aged 65 years and older. All patients underwent coronary angiography. Dipyridamole perfusion scintigraphy was performed safely in all patients. Multiple regression analysis showed that fixed defect and reversible defect were powerful detectors of coronary lesions, all patients with fixed disease and 94% of patients with only reversible defects had significant coronary lesion. Diffuse slow washout and ST depression were statistically significant for detection multivessel coronary lesions in patients with fixed disease, the sensitivity and specificity of diffuse slow washout and/or ST depression for detecting multivessel coronary lesions were 85% and 74%, respectively. Cox survival analysis identified diffuse slow washout as the best predictor of future cardiac events among the scintigraphic variables. Univariate analysis showed the best predictors were age (≥70), diffuse slow washout, and severe coronary lesions. Multivariate analysis showed diffuse slow washout and severe coronary lesions were the best predictors. Dividing the patients by age (≥70) showed that age and diffuse slow washout were good predictors. Scintigraphic and angiographic parameters found diffuse slow washout was the only good predictor. Dipyridamole perfusion scintigraphy is useful for the noninvasive detection of significant coronary artery disease in the elderly, and for predicting future cardiac events with similar predictability to angiographic findings. (S.Y.)

The usefulness of dipyridamole thallium-201 single photon emission computed tomography for predicting perioperative cardiac events in patients undergoing non-cardiac vascular surgery

International Nuclear Information System (INIS)

Chen Tao; Huang Gang

2004-01-01

The aim of this study was to evaluate the usefulness of dipyridamole Tl-201 myocardium single photon emission computed tomography (201Tl-SPECT) for predicting perioperative cardiac events in patients with arteriosclerosis obliterans (ASO) and abdominal aortic aneurysm (AAA) undergoing non-cardiac vascular surgery. Methods: Preoperative dipyridamole 201Tl-SPECT imaging in association with clinical risk assessment was performed in 224 consecutive patients (97 ASO and 127 AAA). Results: The patients were classified into three groups, including low-risk (n=173, 77%), intermediate-risk (n=39, 18%), and high-risk (n=12, 5%) groups according to the clinical risk stratification. The prevalence of reversible Tl-201 defect was significantly higher in the high-risk group than that in the low-risk group (83% vs. 14%, p<0.001). In 180 patients who underwent vascular surgery, 9 patients (5.0%) had perioperative cardiac events, including heart failure (n=l), unstable angina (n=2), and other cardiac events such as arrhythmias (n=6). The clinical variables including the clinical risk stratification did not significantly correlate with the perioperative cardiac events. In contrast, the reversible defect on 201Tl-SPECT was the only variable to predict perioperative cardiac events by a stepwise logistic regression analysis (odds ratio 7.0, 95% confidence interval l.7-28.0, p=0.007). It was also a significant predictor of perioperative cardiac events in a subgroup of low risk patients (odds ratio 11.6, 95% confidence interval 2.3-57.4, p=0.004). The sensitivity and specificity of the reversible defect for predicting perioperative cardiac events were 55.6% and 84.8% in all operated patients, and 57.1% and 89.7% in low risk patients, respectively. Conclusions: The preoperative dipyridamole 201Tl-SPECT was useful for predicting perioperative cardiac events in patients with vascular diseases, even in patients identified as having a low risk based on the clinical risk assessment. (authors)

Noninvasive detection and assessment of coronary artery disease by dipyridamloe thallium-201 imaging

International Nuclear Information System (INIS)

Jiang Maosong

1988-01-01

Dipyridamole (DP) thallium-201 perfusion scintigraphy was performed in 73 patients. IV DP (0.56 mg/kg) infused over 4 min. resulted in an increases in mean HR from 74 +- 12 bpm to a peak of 86 +- 12 bpm (p 201 Tl scintigraphy appears highly sensitive for the diagnosis of coronary artery highly sensitive for the diagnosis of coronary artery disease and provides a useful alternative test for patients who are unable to perform maximal exercise

Thallium-201 infusion imaging

International Nuclear Information System (INIS)

Alazraki, N.; Kralios, A.; Wooten, W.W.

1988-01-01

To test the accuracy of Thallium-201 coronary artery infusion imaging of the earth during rapid changes in blood flow through a major coronary artery, the author performed a study in dogs correlating electromagnetic flow probe recordings with 201 Tl scintillation camera acquisitions. Hyperemic vascular response was produced experimentally in a major coronary artery by occlusion and release interventions which altered flow from baseline to zero during occlusion (20 seconds), followed by rapid flow increases approaching three times baseline immediately upon release of the occlusion. Flow returned to the baseline level within 60 seconds following release. Flow was also altered in a controlled fashion by other interventions. Recordings of Thallium uptake in the myocardium were displayed as a time histogram (counts per second squared vs time) which correlated very closely with electromagnetic flow probe recordings of flow (R=o.82-0.97). These experiments demonstrate a high degree of accuracy in Thallium infusion imaging to detect rapid changes in flow through a major coronary artery

Effect of eating on thallium myocardial imaging

International Nuclear Information System (INIS)

Wilson, R.A.; Sullivan, P.J.; Okada, R.D.; Boucher, C.A.; Morris, C.; Pohost, G.M.; Strauss, H.W.

1986-01-01

To determine if eating between initial and delayed thallium images alters the appearance of the delayed thallium scan, a prospective study was performed; 184 subjects sent for routine thallium imaging were randomized into two groups, those who ate a meal high in carbohydrates between initial and delayed thallium myocardial images (n = 106), and those who fasted (n = 78). The 201 Tl images were interpreted in blinded fashion for global myocardial and pulmonary clearance of 201 Tl myocardial defects. The eating group had a significantly lower incidence of transient myocardial defects compared to the noneating group (7 percent vs 18 percent, respectively; p less than 0.05). The time between initial and delayed images and the incidence of exercise-induced ischemic ST-segment depression or pathologic Q waves on the electrocardiogram were not significantly different between the two groups. These data suggest that eating a high-carbohydrate meal between initial and delayed 201 Tl images causes increased 201 Tl myocardial clearance rates and may alter 201 Tl myocardial redistribution over time

Thallium-201 stress imaging in hypertensive patients

International Nuclear Information System (INIS)

Schulman, D.S.; Francis, C.K.; Black, H.R.; Wackers, F.J.

1987-01-01

To assess the potential effect of hypertension on the results of thallium-201 stress imaging in patients with chest pain, 272 thallium-201 stress tests performed in 133 hypertensive patients and 139 normotensive patients over a 1-year period were reviewed. Normotensive and hypertensive patients were similar in age, gender distribution, prevalence of cardiac risk factors (tobacco smoking, hyperlipidemia, and diabetes mellitus), medications, and clinical symptoms of coronary disease. Electrocardiographic criteria for left ventricular hypertrophy were present in 16 hypertensive patients. Stepwise probability analysis was used to determine the likelihood of coronary artery disease for each patient. In patients with mid to high likelihood of coronary disease (greater than 25% probability), abnormal thallium-201 stress images were present in 54 of 60 (90%) hypertensive patients compared with 51 of 64 (80%) normotensive patients. However, in 73 patients with a low likelihood of coronary disease (less than or equal to 25% probability), abnormal thallium-201 stress images were present in 21 patients (29%) of the hypertensive group compared with only 5 of 75 (7%) of the normotensive patients (p less than 0.001). These findings suggest that in patients with a mid to high likelihood of coronary artery disease, coexistent hypertension does not affect the results of thallium-201 exercise stress testing. However, in patients with a low likelihood of coronary artery disease, abnormal thallium-201 stress images are obtained more frequently in hypertensive patients than in normotensive patients

Ecg changes after dipyridamole infusion in patients undergoing myocardial perfusion imaging

International Nuclear Information System (INIS)

Taherpour, M.; Zakavi, R.; Ariana, K.

2002-01-01

Dipyridamole is used as the main pharmacological stress agent in patient referred for myocardial perfusion imaging. This vasodilator agent makes difference between normal and abnormal coronary perfusion. Some authors believe that post-Dipyridamole Ecg changes have low sensitivity and relatively high specificity for ischemic detection. This study tries to evaluate this issue. All patients who referred to nuclear medicine department for Myocardial Perfusion Imaging and were not suitable for treadmill E T T, and had no L BBB pattern in basal Ecg were included in the study. Basal and post Dipyridamole Ecg were interpreted with a cardiologist after infusion of 142 u g/kg/min of Dipyridamole and all changes as well as basal Ecg abnormalities were recorded. Also Q Tc were calculated in all Ecg records: M P Is were interpreted by a nuclear medicine specialist and summed stress and rest scores were determined. Two hundred patients including 89 female (44.5%) and 111 male (55.5%) with a mean age of 55.2 years and age range of 30-85 years were studied. Mean basal and post Dipyridamole heart rates were 72.2/min and 84.8/min and mean basal and post Dipyridamole Qt Cs were 419.6 msec and 435.7 msec respectively. New Ecg changes were noted in 22.5% of cases and consisted of 1% T-wave flattening, 1% T-wave inversion, 16.5% St depression and 4% Pseudo normalization. Horizontal pattern was the main type of St segment depression (83.%) among new S T changes. Mean St depression severity was 0.8 mm with a range of 0.5-2 mm. New St depression was noted in lateral leads (Excluding high lateral) in 62.5% of new S T changes. M P I was interpreted normal in 4% of cases and showed some degrees of ischemia in 42% of the cases. The mean post Dipyridamole heart rate increment, was 11.2/ min patients with abnormal scintigraphy (infarct and/or ischemia) compared to 14.5/ min in normal cases. (P=0.009). Also Qt c increment in patients with ischemia was significantly more than patients with simple

Thallium-201 myocardial imaging in young adults with anomalous left coronary artery arising from the pulmonary artery

International Nuclear Information System (INIS)

Moodie, D.S.; Cook, S.A.; Gill, C.C.; Napoli, C.A.

1980-01-01

Anomalous origin of the left coronary artery from the pulmonary artery (Bland-Garland-White syndrome) may produce myocardial ischemia, infarction, and frequently death in infancy. Some patients, however, develop satisfactory coronary artery collaterals and are relatively asymptomatic into adulthood. Very little is known about their myocardial perfusion patterns. We studied three young adults with this condition using stress thallium-201 myocardial imaging. Electrocardiograms in two patients demonstrated old arterolateral myocardial infarctions. Preoperative stress exercise tests were positive in all three patients. Marked perfusion abnormalities were found in the proximal anterolateral wall in all patients, and one patient also had a posterolateral defect. Postoperatively, all stress tests returned to normal. Thallium imaging demonstrated improvement in ischemic areas, but old scars persisted

Clinical utility and problem of thallium myocardial imaging after coronary angioplasty

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Konishi, Tokuji; Tamai, Takuya; Nakamura, Mashio; Miyahara, Masatoshi; Isaka, Naoki; Nakano, Takeshi.

1995-01-01

The purpose of this study was twofold: (1) to assess the value and limits of stress thallium myocardial imaging in the diagnosis of reclosure after percutaneous transluminal coronary angioplasty (PTCA) and (2) to determine how myocardial viability, as determined on thallium imaging, influenced the therapeutic option. In study 1, 117 segments, which were treated with PTCA, were examined. Of 52 segments that showed thallium defects, 27 were treated with repeated PTCA. Of the other 25 segments, 12 were found to be reclosed. On the other hand, 65 other segments showed redistribution on thallium imaging, and 60 of these had no reclosure. The remaining 5 segments that were reclosed reflected no evidence of myocardial viability. These findings suggest that coronary arteriography may omitted when redistribution is seen on stress thallium imaging after PTCA. The population in Study 2 included 39 patients who were diagnosed as having myocardial necrosis on thallium imaging. In 22 of these patients, thallium findings ruled out coronary revascularization. One other patient did not undergo coronary revascularization because of technical problems. Thus, the remaining 16 patients were treated with coronary revascularization combined with bypass surgery for necrotic zones (n=10) or with PTCA for preserved collateral circulation (n=6). For necrotic zones evidenced on thallium imaging, factors other than necrosis were considered in determining coronary revascularization. (N.K.)

Thallium reinjection after stress-redistribution imaging. Does 24-hour delayed imaging after reinjection enhance detection of viable myocardium

International Nuclear Information System (INIS)

Dilsizian, V.; Smeltzer, W.R.; Freedman, N.M.; Dextras, R.; Bonow, R.O.

1991-01-01

Thallium reinjection immediately after conventional stress-redistribution imaging improves the detection of viable myocardium, as many myocardial regions with apparently 'irreversible' thallium defects on standard 3-4-hour redistribution images manifest enhanced thallium uptake after reinjection. Because the 10-minute period between reinjection and imaging may be too short, the present study was designed to determine whether 24-hour imaging after thallium reinjection provides additional information regarding myocardial viability beyond that obtained by imaging shortly after reinjection. We studied 50 patients with chronic stable coronary artery disease undergoing exercise thallium tomography, radionuclide angiography, and coronary arteriography. Immediately after the 3-4-hour redistribution images were obtained, 1 mCi thallium was injected at rest, and images were reacquired at 10 minutes and 24 hours after reinjection. The stress, redistribution, reinjection, and 24-hour images were then analyzed qualitatively and quantitatively. Of the 127 abnormal myocardial regions on the stress images, 55 had persistent defects on redistribution images by qualitative analysis, of which 25 (45%) demonstrated improved thallium uptake after reinjection. At the 24-hour study, 23 of the 25 regions (92%) with previously improved thallium uptake by reinjection showed no further improvement. Similarly, of the 30 regions determined to have irreversible defects after reinjection, 29 (97%) remained irreversible on 24-hour images. These findings were confirmed by the quantitative analysis. The mean normalized thallium activity in regions with enhanced thallium activity after reinjection increased from 57 +/- 13% on redistribution studies to 70 +/- 14% after reinjection but did not change at 24 hours (71 +/- 14%)

The relationship between chest pain during thallium-201 scintigraphy with dipyridamole and myocardial ischemia

International Nuclear Information System (INIS)

Takeishi, Yasuchika; Tono-oka, Ichiro; Meguro, Mitsuhiko; Hoshi, Hikaru; Masakane, Ikuto; Ikeda, Kozue; Tsuiki, Kai; Yasui, Shoji

1991-01-01

Dipyridamole thallium-201 scintigraphy (DP-Tl) and coronary angiography were studied on 74 patients with suspected coronary artery disease. We compared the clinical features, hemodynamic responses, angiographic results and scintigraphic findings of patients who had chest pain during DP-Tl testing ('chest pain' group) with those of patients who did not have chest pain ('no pain' group). Thirty eight (51%) of the 74 patients developed chest pain. Heart rate and rate pressure product during DP infusion of 'chest pain' group were greater than those of the 'no pain' group (p<0.05). Ischemic ST depression was more frequently observed among 'chest pain' patients (p<0.01). There were no differences in angiographic severity of coronary artery disease between 'chest pain' and 'no pain' group. Also, we could find no differences in extent and severity scores of perfusion defects and washout abnormalities between the two groups. However, when patients with myocardial infarction were excluded, the 'chest pain' group had significantly greater extent and severity scores of washout abnormalities than the 'no pain' group (extent score: 38±8 vs 18±5, p<0.05, severity score: 55±15 vs 18±7, p<0.01). Our study indicated that in patients without myocardial infarction, patients with 'chest pain' had more severe ischemia than 'no pain' patients. But in patients with myocardial infarction, myocardial ischemia not accompanied by chest pain might be as severe as that with chest pain. The presence or absence of myocardial infarction might have great influence on results regarding the relation of chest pain to myocardial ischemia. (author)

Prognostic implications of normal exercise thallium 201 images

International Nuclear Information System (INIS)

Wahl, J.M.; Hakki, A.H.; Iskandrian, A.S.

1985-01-01

A study was made of 455 patients (mean age, 51 years) in whom exercise thallium 201 scintigrams performed for suspected coronary artery disease were normal. Of those, 322 (71%) had typical or atypical angina pectoris and 68% achieved 85% or more maximal predicted heart rate. The exercise ECGs were abnormal in 68 patients (15%), normal in 229 (50%), and inconclusive in 158 (35%). Ventricular arrhythmias occurred during exercise in 194 patients (43%). After a mean follow-up period of 14 months, four patients had had cardiac events, sudden cardiac death in one and nonfatal myocardial infarctions in three. None of the four patients had abnormal exercise ECGs. Two had typical and two had atypical angina pectoris. Normal exercise thallium 201 images identify patients at a low risk for future cardiac events (0.8% per year), patients with abnormal exercise ECGs but normal thallium images have good prognoses, and exercise thallium 201 imaging is a better prognostic predictor than treadmill exercise testing alone, because of the high incidence of inconclusive exercise ECGs and the good prognosis in patients with abnormal exercise ECGs

Dipyridamole-thallium-201 tomography documenting improved myocardial perfusion with therapy in Kawasaki disease

International Nuclear Information System (INIS)

Nienaber, C.A.; Spielmann, R.P.; Hausdorf, G.

1988-01-01

Thallium-201 tomographic perfusion studies after pharmacologic vasodilation were performed in seven children (aged 2 years 8 months to 8 years 7 months), 3 to 20 months after the acute stage of the disease. In all patients coronary aneurysms were seen on cross-sectional echocardiograms. The scintigrams of six children showed no significant regional reduction of myocardial thallium-201 uptake. These children had remained asymptomatic in the follow-up period after the acute inflammatory stage of Kawasaki disease. Persistent and transient thallium defects were present in one child with acute posterolateral myocardial infarction; obstruction of two coronary vessels supplying the defect zones was confirmed by contrast angiography. After 8 months of treatment a follow-up nuclear scan showed marked reduction in the size of the defect and almost complete abolishment of the ischemic reaction. Thus tomographic thallium-201 perfusion scintigraphy in conjunction with vasodilation stress is useful to assess myocardial perfusion in children with Kawasaki disease and demonstrates marked improvement in regional perfusion after adequate medical therapy

Thallium-201 myocardial imaging in the detection of coronary artery disease

International Nuclear Information System (INIS)

McKillop, J.H.; Murray, R.G.; Turner, J.G.; Gray, H.W.; Bessent, R.G.; Lorimer, A.R.; Greig, W.R.

1978-01-01

Thallium-201 myocardial imaging can detect abnormalities of myocardial perfusion. Visual interpretation of the images is complicated by some inhomogeneity of tracer uptake normally present. Using a quantitative approach we have established the regional variation of Thallium-201 uptake present in 23 normal controls and applied the same technique to 49 patients who had undergone selective coronary arteriography with left ventriculography because of chest pain. Half of the patients with significant coronary artery disease had abnormal rest Thallium-201 images, usually corresponding to areas of abnormal wall motion at ventriculography. Stress Thallium-201 images were abnormal in over 90% of patients with coronary artery disease. The stress image abnormalities and the arteriographic lesions correlated well in most patients with single and double vessel disease but in triple vessel disease the correspondence between the two studies was poor. Two of a group of patients with normal coronary arteriograms had abnormal Thallium-201 images due to other myocardial pathology. Our technique was highly sensitive in the non-invasive detection of significant coronary artery disease in a group of patients with chest pain. A small number of positive studies were also encountered due to other myocardial disorders. (author)

Serial Myocardial Imaging after a Single Dose of Thallium-201

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Takahiko Kamata

2014-10-01

Full Text Available Although thallium-201 exercise scintigraphy has been established for the detection of myocardial ischemia and viability, little is known regarding the myocardial thallium-201 kinetics during angioplasty. Herein, we report a 77-year old man with angina pectoris, in whom serial myocardial imaging after a single dose of thallium-201 was helpful in identifying not only the culprit lesion and myocardial viability, but also the dynamic changes in myocardial perfusion during angioplasty. Thallium-201 images after exercise showed a perfusion defect in the inferior wall, with a trivial redistribution 3 hours after the exercise and a marked improvement 24 hours later. Coronary angiography, performed 27 hours after exercise scintigraphy, showed severe stenosis in the right coronary artery. Guidewire crossing of the lesion interrupted the antegrade flow, which was restored after balloon dilation and stent implantation. Thallium-201 images, 2 hours after angioplasty (i.e., 30 hours after exercise, showed a decreased tracer uptake in the inferior wall, which improved the next day (i.e., 48 hours after exercise. Cardiac biomarkers were negative in the clinical course.

Quantitative thallium-201 scintigraphy after dipyridamole infusion combined with low level exercise in healthy volunteers

International Nuclear Information System (INIS)

Laarman, G.J.; Niemeyer, M.G.; Ascoop, C.A.P.L.; Bruschke, A.V.G.; Wall, E.E. van der; Verzijlbergen, F.J.; Liam Go, T.

1989-01-01

To establish test specific normal limits for quantitative analysis of uptake and washout of 201 Tl after dipyridamole infusion combined with low level exercise, 20 healthy volunteers were studied with low likelihood of coronary artery disease (CAD) assessed by a stepwise probability analysis based on age, sex, symptoms, resting electrocardiogram, and exercise electrocardiography. Likelihood of CAD in these volunteers was calculated as ≤ 1%. After dipyridamole infusion combined with low level exercise, one volunteer complained of headache; no other side effects were observed. There were no chest pain complaints. Maximal hemodynamic changes were achieved during the 6th and 7th min of the test. No ST segment depression was recorded. Visual analysis of the 201 Tl scintigrams was normal in all volunteers. Mean regional washout at 4 h was 44.37%±2.11%. The regional washout in the 70 0 LAO view (46.65%±1.10%) was significantly higher than in the anterior and 30 0 LAO views (43.44%±1.50% and 43.02%±1.45%, respectively). Profiles of uptake and washout of 201 Tl were different after dipyridamole infusion combined with low level exercise as compared to maximal exercise. Thus, in quantitative analysis of 201 Tl scintigraphy after dipyridamole infusion in conjunction with low level exercise as applied in the present study, it is mandatory to use normal limits of uptake and washout of 201 Tl derived from healthy volunteers who underwent the same combined protocol. (orig.)

Dipyridamole 201Tl scintigraphy in the evaluation of prognosis after myocardial infarction

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Okada, R.D.; Glover, D.K.; Leppo, J.A.

1991-01-01

Dipyridamole 201Tl imaging has been proposed as an alternative to exercise ECG testing for the prehospital discharge evaluation of patients recovering from myocardial infarction. The rationale is that many postinfarction patients with exercise-induced ischemia experience later cardiac events, and the sensitivity of predischarge exercise ECG testing in patients with multivessel disease ranges from only 45% to 62%. In addition, several groups of investigators have shown the sensitivity of submaximum exercise 201Tl imaging to be less than ideal. This report summarizes the current status of dipyridamole 201Tl imaging in the period of 1-13 days after myocardial infarction. Although the number of studies performed to date is limited, the following conclusions can be drawn: dipyridamole 201Tl imaging after myocardial infarction was associated with no serious side effects, and those present could be quickly reversed with aminophylline; redistribution with dipyridamole 201Tl images definitely correlates with prognosis after uncomplicated myocardial infarction; dipyridamole 201Tl imaging is definitely useful in patients unable to exercise for a variety of reasons; and future studies are definitely indicated to further define the role of dipyridamole 201Tl imaging for assessing prognosis, especially in those patients undergoing interventional therapy after acute myocardial infarction

Caffeine reduces dipyridamole-induced myocardial ischemia

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Smits, P.; Aengevaeren, W.R.; Corstens, F.H.; Thien, T.

1989-01-01

The mechanism of action of coronary vasodilation after dipyridamole may be based on inhibition of cellular uptake of circulating endogenous adenosine. Since caffeine has been reported to be a competitive antagonist of adenosine we studied the effect of caffeine on the outcome of dipiridamole- 201 Tl cardiac imaging in one patient. During caffeine abstinence dipyridamole induced myocardial ischemia with down-slope ST depressions on the ECG, and reversible perfusion defects on the scintigrams. When the test was repeated 1 wk later on similar conditions, but now shortly after infusion of caffeine (4 mg/kg), the ECG showed nodepressions, and the scintigrams only slight signs of ischemia. We conclude that when caffeine abstinence is not sufficient, the widespread use of coffee and related products may be responsible for false-negative findings in dipyridamole-201Tl cardiac imaging

Caffeine reduces dipyridamole-induced myocardial ischemia

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Smits, P.; Aengevaeren, W.R.; Corstens, F.H.; Thien, T. (Univ. of Nijmegen (Netherlands))

1989-10-01

The mechanism of action of coronary vasodilation after dipyridamole may be based on inhibition of cellular uptake of circulating endogenous adenosine. Since caffeine has been reported to be a competitive antagonist of adenosine we studied the effect of caffeine on the outcome of dipiridamole-{sup 201}Tl cardiac imaging in one patient. During caffeine abstinence dipyridamole induced myocardial ischemia with down-slope ST depressions on the ECG, and reversible perfusion defects on the scintigrams. When the test was repeated 1 wk later on similar conditions, but now shortly after infusion of caffeine (4 mg/kg), the ECG showed nodepressions, and the scintigrams only slight signs of ischemia. We conclude that when caffeine abstinence is not sufficient, the widespread use of coffee and related products may be responsible for false-negative findings in dipyridamole-201Tl cardiac imaging.

Acute myocardial infarction associated with intravenous dipyridamole for rubidium-82 PET imaging

International Nuclear Information System (INIS)

Marwick, T.H.; Hollman, J.

1990-01-01

This report describes the occurrence of chest pain and electrocardiographic features of acute myocardial infarction following intravenous dipyridamole-handgrip stress. Myocardial perfusion imaging (Rb-82 PET) demonstrated a stress-induced perfusion defect. Following failure to respond to medical therapy, urgent cardiac catheterization demonstrated total occlusion of the left anterior descending coronary artery. The vessel was revascularized, with limitation of myocardial damage evidenced by failure to develop anterior Q waves and only modest elevation of cardiac enzyme levels. Complications of intravenous dipyridamole stress are rare, this case constituting the first major problem in over 500 such procedures at this institution. However, this experience demonstrates the importance of vigilant observation during the performance of this technique

Comparison of exercise electrocardiography and quantitative thallium imaging for one-vessel coronary artery disease

International Nuclear Information System (INIS)

Kaul, S.; Kiess, M.; Liu, P.; Guiney, T.E.; Pohost, G.M.; Okada, R.D.; Boucher, C.A.

1985-01-01

The relative value of exercise electrocardiography and computer analyzed thallium-201 imaging was compared in 124 patients with 1-vessel coronary artery disease (CAD). Of these, 78 had left anterior descending (LAD), 32 right and 14 left circumflex (LC) CAD. In patients with no previous myocardial infarction (MI), thallium imaging was more sensitive than the electrocardiogram (78% vs 64%, p less than 0.01), but in patients with previous MI, sensitivity was similar. Further, thallium imaging was more sensitive only in LAD and LC disease. Redistribution was compared with ST-segment depression as a marker of ischemia. Only in patients with prior MI (76% vs 44%, p less than 0.01) and only in LC and right CAD did redistribution occur more often than ST depression. Thallium imaging was more accurate in localizing stenoses than the electrocardiogram (p less than 0.001), but did not always correctly predict coronary anatomy. Septal thallium defects were associated with LAD disease in 84%, inferior defects with right CAD in 40% and posterolateral lesion defects with LC CAD in 22%. The results indicate the overall superiority of thallium imaging in 1-vessel CAD compared with exercise electrocardiography; however, there is a wide spectrum of extent and location of perfusion defects associated with each coronary artery. Thallium imaging complements coronary angiography by demonstrating the functional impact of CAD on myocardial perfusion

Thallium-201 is comparable to technetium-99m-sestamibi for estimating cardiac function in patients with abnormal myocardial perfusion imaging

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Ming-Che Wu

2015-11-01

Full Text Available We analyzed the left-ventricular functional data obtained by cardiac-gated single-photon emission computed tomography myocardial perfusion imaging (MPI with thallium-201 (Tl-201 and technetium-99m-sestamibi (MIBI protocols in different groups of patients, and compared the data between Tl-201 and MIBI. Two hundred and seventy-two patients undergoing dipyridamole stress/redistribution Tl-201 MPI and 563 patients undergoing 1-day rest/dipyridamole stress MIBI MPI were included. Higher mean stress ejection fraction (EF, rest EF, and change in EF (ΔEF were noticed in the normal MPI groups by both Tl-201 and MIBI protocols. Higher mean EF was observed in the females with normal MPI results despite their higher mean age. Comparisons between the Tl-201 and MIBI groups suggested a significant difference in all functional parameters, except for the rest end diastolic volume/end systolic volume and ΔEF between groups with negative MPI results. For the positive MPI groups, there was no significant difference in all parameters, except for the change in end diastolic volume and change in end systolic volume after stress between both protocols. The Tl-201 provides comparable left-ventricular functional data to MIBI cardiac-gated single-photon emission computed tomography in patients with positive MPI results, and may therefore be undertaken routinely for incremental functional information that is especially valuable to this patient group.

Thallium-201 imaging in children with osteogenic sarcoma

International Nuclear Information System (INIS)

Parker, M.K.; Koutsiofi, M.; Rossleigh, M.A.

2003-01-01

Full text: Thallium(Tl)-201 scintigraphy has been utilised in the imaging of a variety of tumours. This study evaluates its usefulness in children with osteogenic sarcoma. Five patients (3 male, 2 female) whose ages ranged from 11 to 15 years were investigated. Each child underwent a baseline 201 Tl study at diagnosis to determine the initial avidity of the tumour and a follow up study following chemotherapy, just prior to surgical excision, to assess tumour response to chemotherapy. This tumour response was confirmed by histopathological examination of the operative specimen. 201 Tl scintigraphy was undertaken 20 minutes following the intravenous administration of a weight adjusted dose of 201 Tl (minimum dose 20 MBq, adult dose 120 MBq). Whole body studies as well as planar images of the primary tumour were performed. All primary tumours were thallium avid on the baseline study. On the follow-up examination after therapy, a variety of patterns of uptake were seen and these correlated with the pathological findings. In one patient, complete loss of thallium accumulation following treatment corresponded to 100% tumour necrosis histologically. In another patient, persistent thallium uptake in the tumour following chemotherapy correlated with viable tumour cells on pathology and this patient died of his disease. In the other 3 patients, intermediate grade thallium appearances were demonstrated. In conclusion, 201 Tl scintigraphy is an excellent marker of osteogenic sarcoma and follow-up studies after chemotherapy accurately reflect residual tumour activity when correlated with histology. Copyright (2003) The Australian and New Zealand Society of Nuclear Medicine Inc

Exercise thallium imaging in patients with diabetes mellitus. Prognostic implications

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Felsher, J.; Meissner, M.D.; Hakki, A.H.; Heo, J.; Kane-Marsch, S.; Iskandrian, A.S.

1987-01-01

We used exercise thallium 201 imaging in 123 patients with diabetes mellitus (77 men and 46 women, aged 56 +/- 8 years), 75% of whom had angina pectoris (typical or atypical). During exercise testing, 18 patients (15%) had angina pectoris, 28 (23%) had ischemic ST changes, and 69 (56%) had abnormal thallium images. During follow-up (up to 36 months), there were 12 cardiac events; four patients died of cardiac causes and eight had nonfatal acute myocardial infarction. Univariate and multivariate survival analysis identified two independent predictors of cardiac events: the event rate was significantly less in patients with normal images and exercise heart rate over 120 beats per minute than in patients with abnormal images and exercise heart rate of 120 beats per minute or less (0% vs 22%). The patients with abnormal images or exercise heart rate of 120 beats per minute or less had an intermediate event rate (11.5%). Furthermore, two of the 54 patients with normal images and ten of 69 patients with abnormal images had subsequent cardiac events. Thus, exercise thallium imaging is useful in risk stratification in patients with diabetes mellitus

Time sequential single photon emission computed tomography studies in brain tumour using thallium-201

International Nuclear Information System (INIS)

Ueda, Takashi; Kaji, Yasuhiro; Wakisaka, Shinichiro; Watanabe, Katsushi; Hoshi, Hiroaki; Jinnouchi, Seishi; Futami, Shigemi

1993-01-01

Time sequential single photon emission computed tomography (SPECT) studies using thallium-201 were performed in 25 patients with brain tumours to evaluate the kinetics of thallium in the tumour and the biological malignancy grade preoperatively. After acquisition and reconstruction of SPECT data from 1 min post injection to 48 h (1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and 15-20 min, followed by 4-6, 24 and 48 h), the thallium uptake ratio in the tumour versus the homologous contralateral area of the brain was calculated and compared with findings of X-ray CT, magnetic resonance imaging, cerebral angiography and histological investigations. Early uptake of thallium in tumours was related to tumour vascularity and the disruption of the blood-brain barrier. High and rapid uptake and slow reduction of thallium indicated a hypervascular malignant tumour; however, high and rapid uptake but rapid reduction of thallium indicated a hypervascular benign tumour, such as meningioma. Hypovascular and benign tumours tended to show low uptake and slow reduction of thallium. Long-lasting retention or uptake of thallium indicates tumour malignancy. (orig.)

Enhanced detection of ischemic but viable myocardium by the reinjection of thallium after stress-redistribution imaging

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Dilsizian, V.; Rocco, T.P.; Freedman, N.M.; Leon, M.B.; Bonow, R.O.

1990-01-01

The identification of ischemic but viable myocardium by thallium exercise scintigraphy is often imprecise, since many of the perfusion defects that develop in ischemic myocardium during exercise do not fill in on subsequent redistribution images. We hypothesized that a second injection of thallium given after the redistribution images were taken might improve the detection of ischemic but viable myocardium. We studied 100 patients with coronary artery disease, using thallium exercise tomographic imaging and radionuclide angiography. Patients received 2 mCi of thallium intravenously during exercise, redistribution imaging was performed three to four hours later, and a second dose of 1 mCi of thallium was injected at rest immediately thereafter. The three sets of images (stress, redistribution, and reinjection) were then analyzed. Ninety-two of the 100 patients had exercise-induced perfusion defects. Of the 260 abnormal myocardial regions identified by stress imaging, 85 (33 percent) appeared to be irreversible on redistribution imaging three to four hours later. However, 42 of these apparently irreversible defects (49 percent) demonstrated improved or normal thallium uptake after the second injection of thallium, with an increase in mean regional uptake from 56 +/- 12 percent on redistribution studies to 64 +/- 10 percent on reinjection imaging (P less than 0.001). Twenty patients were restudied three to six months after coronary angioplasty. Of the 15 myocardial regions with defects on redistribution studies that were identified as viable by reinjection studies before angioplasty, 13 (87 percent) had normal thallium uptake and improved regional wall motion after angioplasty. In contrast, all eight regions with persistent defects on reinjection imaging before angioplasty had abnormal thallium uptake and abnormal regional wall motion after angioplasty

Thallium imaging in management of post-revascularization patients

International Nuclear Information System (INIS)

Alazraki, N.; Krawczynska, E.

1996-01-01

The role of myocardial perfusion imaging in the evaluation of post revascularization patients has not been well defined. Published data with special emphasis on the results from the Emory Angioplasty versus Surgery Trial (EAST) indicate that the frequency of adverse cardiac events (death, MI, repeat revascularization) following PTCA or CABG is equal in symptomatic and asymptomatic patients with ischemic thallium defects. Current American Heart Association Guidelines recommend radionuclide studies only in symptomatic patients. Recently reported data support the need for non invasive testing in asymptomatic as well as symptomatic patients at 1 year postrevascularization. Prognostic variables including transient and permanent left ventricular dilatation and thallium lung uptake in addition to stress perfusion defect reversibility on myocardial thallium SPECT scans are important prognostic indicators in post revascularization patients

Detection of human collateral circulation by vasodilation-thallium-201 tomography

International Nuclear Information System (INIS)

Nienaber, C.A.; Salge, D.; Spielmann, R.P.; Montz, R.; Bleifeld, W.

1990-01-01

Coronary arteriolar vasodilation may provoke redistribution of flow to collateral-dependent jeopardized myocardium. To assess the physiologic significance of collaterals, 80 consecutive post-infarction patients (age 58 +/- 8 years) underwent vasodilation-redistribution thallium-201 tomographic imaging after administration of 0.56 mg of intravenous dipyridamole/kg body weight. Circumferential profile analysis of thallium-201 uptake and redistribution in representative left ventricular tomograms provided quantitative assessment of transient and fixed defects and separation between periinfarctional and distant inducible hypoperfusion. Tomographic perfusion data were correlated to wall motion and collateral circulation between distinct anatomic perfusion territories. Patients were grouped according to presence (59%) or absence (41%) of angiographically visible collateral channels to jeopardized myocardium. In the presence of collaterals, distant reversible defects were larger than in absence of collaterals (p less than 0.05); the extent of combined periinfarctional and distant redistribution was also larger in collateralized patients (p less than 0.025), whereas the size of the persistent perfusion defect was similar in both groups. By prospective analysis the tomographic perfusion pattern of combined periinfarctional and distant redistribution revealed a sensitivity of 85% and a specificity of 78% for the detection of significant collateral circulation in this group of patients. Thus, using the exhausted flow reserve as a diagnostic tool, vasodilation-thallium-201 tomography has the potential to identify and quantitate collateralized myocardium in post-infarction patients and may guide diagnostic and therapeutic decision-making

Preoperative localization of parathyroid adenomas by technetium and thallium double-labeling scintigraphy. Difficulties linked to associated thyroid lesions

International Nuclear Information System (INIS)

Valensi, P.; Attali, J.R.; Sebaoun, J.; Bedig, G.; Paycha, F.; Tellier, P.; Vulpillat, M.; Sarfati, E.; Dubost, C.

1989-01-01

Technetium and thallium double-labeling scintigraphy with image subtraction was carried out on 63 patients suspected of having primary hyperparathyroidism, with or without thyroid involvement. Forty-four patients had a normal thyroid image with technetium. The positive foci located by double-labeling in patients who were to undergo surgery always coincided with parathyroid adenoma. In the 16 cases where the initial diagnosis of hyperparathyroidism was not substantiated, the double-labeling test was normal. Thus for these 44 patients, scintigraphy sensitivity was 75% and specificity was 100%. Nineteen patients had an abnormal thyroid image with technetium. In 7 cases, image subtraction following double-labeling yielded uninterpretable data. In 12 other patients, the positive foci located outside the thyroid by double-labeling coincided with a parathyroid adenoma, whereas this was true for only one patient whose positive foci were located inside the thyroid; a parathyroid adenoma was not detected preoperatively in 4 patients. This double-labeling test is thus useful in locating parathyroid adenomas when technetium scintigraphy of the thyroid is normal; when it is abnormal, double-labeling is advantageous only in cases of extrathyroid foci [fr

Myocardial imaging in coronary heart disease with radionuclides, with emphasis on thallium-201

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Wackers, F J.Th.; Sokole, E B; Samson, G; van der Schoot, J B; Wellens, H J.J. [Amsterdam Univ. (Netherlands). Academisch Ziekenhuis

1976-09-01

During the past few years there has been an increasing interest in cardiology for myocardial imaging with radionuclides. At present the experience with both negative (thallium-201) and positive (sup(99m)Tc-pyrophosphate) imaging of myocardial infarction is increasing rapidly. Since 1974, over 1100 patient studies with thallium-201 were performed. In this article a survey is presented of experience with thallium-201 in patients with acute and chronic coronary artery disease. In patients with acute myocardial infarction data from studies with sup(99m)Tc-pyrophosphate will be discussed as well.

Evaluation in dogs of a new double-dose technique for imaging changes in myocardial perfusion

International Nuclear Information System (INIS)

Rothendler, J.A.; Okada, R.D.; Strauss, H.W.; Chesler, D.A.; Pohost, G.M.

1984-01-01

Assessment of myocardial perfusion with thallium immediately before and after an intervention that alters blood flow has been difficult due to presence of residual activity from the first tracer dose at the time of the second imaging. In a canine model the authors investigated a technique using two separate thallium injections during an intervention and after its reversal. Images were obtained after each injection, and a difference image was obtained by subtracting the first from the second image to correct for tracer persisting from the first injection. Interventions on coronary blood flow included: transient occlusion, subcritical stenosis with dipyridamole infusion, and permanent occlusion. The first images showed defects corresponding to the occlusion or stenosis, while the ''difference'' images correlated with myocardial perfusion at the time of the second injection

Sex differences in the tracer distribution on stress thallium-201 imaging, (1)

International Nuclear Information System (INIS)

Tamaki, Nagara; Koda, Hideki; Adachi, Yukihide; Sugihara, Takao; Kato, Mihoko; Tanaka, Nobuyuki; Tamari, Kimimasa.

1988-01-01

To determine the sex differences in the tracer distribution on stress thallium-201 imaging, the studies of 18 normal males and 18 normal females were subjected to quantitative circumferential profile analysis in each projection image. Although the exercise duration was shorter in females (11±3 min) than in males (14±3 min) (p<0.01), the peak heart rate, peak systolic pressure and the lung-to-myocardial count ratio were similar between them. The averaged profile curves in female showed a significant reduction in tracer uptake in anterior and upper septal regions, particularly in the study of lateral view, which may be attributed to breast attenuation. In addition, the percent washout of thallium in 3 hours was higher in females (48±8%) than in males (43±7%) (p<0.01), particularly in the study of anterior view. We conclude that important differences in the pattern of thallium uptake and washout between males and females should be considered for interpretation of stress thallium imaging. (author)

Lung uptake of thallium-201 on resting myocardial imaging in assessment of pulmonary edema

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Tamaki, N.; Yonekura, Y.; Yamamoto, K. (Kyoto Univ. (Japan). Hospital)

1981-03-01

We have noted increased lung uptake of thallium-201 on resting myocardial images in patients with congestive heart failure. To evaluate this phenomenon, lung uptake of thallium on resting myocardial imaging was examined in 328 patients with various cardiovascular diseases. Increased lung uptake was observed in 117 cases (78%) with myocardial infarction, 32 (37%) with angina pectoris, 6 (27%) with hypertensive heart disease, 7 (30%) with hypertrophic cardiomyopathy, 6 (100%) with congestive cardiomyopathy, 11 (100%) with valvular heart disease, and 7 (71%) with congenital heart disease, however, only one (5%) of normal subjects revealed increased uptake. Left ventricular ejection fraction was evaluated in 32 cases with ischemic heart disease on the same day and it was significantly decreased as the lung uptake of thallium increased. Increased thallium activity in the lung seemed to be another noninvasive marker of lift heart failure in ischemic heart disease. Lung uptake of thallium was compared with pulmonary congestive signs on chest X-ray in 29 cases. The uptake was well correlated with the degree of pulmonary edema, and thallium myocardial image revealed remarkably increased lung uptake in all the patients accompanied with pulmonary interstitial edema on chest X-ray. Therefore, this phenomenon will demonstrate pulmonary edema, since thallium may be extracted to the increased interstitial distribution space of the lung as well as the myocardium in a patient with pulmonary edema. We conclude that thallium myocardial scintigraphy is useful not only in identification and localization of myocardial ischemia or infarction, but also in evaluation of pulmonary edema at the same time.

Lung uptake of thallium-201 on resting myocardial imaging in assessment of pulmonary edema

International Nuclear Information System (INIS)

Tamaki, Nagara; Yonekura, Yoshiharu; Yamamoto, Kazutaka

1981-01-01

We have noted increased lung uptake of thallium-201 on resting myocardial images in patients with congestive heart failure. To evaluate this phenomenon, lung uptake of thallium on resting myocardial imaging was examined in 328 patients with various cardiovascular diseases. Increased lung uptake was observed in 117 cases (78%) with myocardial infarction, 32 (37%) with angina pectoris, 6 (27%) with hypertensive heart disease, 7 (30%) with hypertrophic cardiomyopathy, 6 (100%) with congestive cardiomyopathy, 11 (100%) with valvular heart disease, and 7 (71%) with congenital heart disease, however, only one (5%) of normal subjects revealed increased uptake. Left ventricular ejection fraction was evaluated in 32 cases with ischemic heart disease on the same day and it was significantly decreased as the lung uptake of thallium increased. Increased thallium activity in the lung seemed to be another noninvasive marker of lift heart failure in ischemic heart disease. Lung uptake of thallium was compared with pulmonary congestive signs on chest X-ray in 29 cases. The uptake was well correlated with the degree of pulmonary edema, and thallium myocardial image revealed remarkably increased lung uptake in all the patients accompanied with pulmonary interstitial edema on chest X-ray. Therefore, this phenomenon will demonstrate pulmonary edema, since thallium may be extracted to the increased interstitial distribution space of the lung as well as the myocardium in a patient with pulmonary edema. We conclude that thallium myocardial scintigraphy is useful not only in identification and localization of myocardial ischemia or infarction, but also in evaluation of pulmonary edema at the same time. (author)

Decrease in the ability to detect elevated lung thallium due to delay in commencing imaging after exercise

International Nuclear Information System (INIS)

Rothendler, J.A.; Boucher, C.A.; Strauss, H.W.; Pohost, G.M.; Okada, R.D.

1985-01-01

Post-exercise elevation of the lung/myocardial thallium ratio and a high lung clearance rate between initial and delayed images have been reported to be markers for exercise-induced left ventricular (LV) dysfunction associated with coronary artery disease (CAD). The authors performed thallium exercise tests on 60 patients, 42 with CAD, in order to determine the effect of delaying initial imaging on detection of elevated lung thallium. In addition to images obtained at 2 minutes and at 2 hours after exercise, 18-minute images were also obtained to simulate such a delay. Because of rapid isotope clearance in those with initially elevated lung activity, there was decreased sensitivity of both the initial lung/myocardial ratio and lung thallium clearance for detecting CAD, using the 18-minute image as the initial post exercise study. They conclude that initial imaging should be done in the anterior view early after exercise to optimize detection of elevated lung thallium

Role of exercise thallium 201 imaging in decision making

International Nuclear Information System (INIS)

Iskandrian, A.S.; Hakki, A.H.; Segal, B.L.; Frankl, W.S.; Kane-Marsch, S.; Unger, J.

1986-01-01

This prospective study examined the impact of results of exercise thallium 201 imaging on the estimation of probability of coronary artery disease (CAD) and patient management among cardiologists and internists in our institution. Before exercise testing, the probability of CAD in the 100 patients enrolled in this study was considered low in 31, intermediate in 28, and high in 41 patients. The probability of CAD after exercise thallium imaging was different in four patients (10%) in the high group, 22 patients (79%) in the intermediate group, and three patients (10%) in the low group. Further, the results of exercise testing resulted in changes in patient management in 29 patients (71%) in the high group, 26 patients (93%) in the intermediate group, and 16 patients (52%) in the low group. Overall, the management changed in 71% of the patients. This change included changes in medications, physical activity, frequency of office visits, need for cardiac catheterization, and need for coronary arterial bypass grafting. Thus, exercise thallium imaging is useful in clinical decision making: the diagnostic certainty is improved in patients with intermediate pretest probability of CAD; and some degree of change in patient management is observed, even in patients in whom the probability of CAD is not altered

Value of dipyridamole stress 201Tl myocardial SPECT in detecting dysfunction of coronary microcirculation

International Nuclear Information System (INIS)

Lou Ying; Jiang Jinqi; Xie Wenhui; Yuan Fang; Wang Tong; Yang Yiqing

2012-01-01

Objective: To evaluate the value of dipyridamole stress 201 Tl myocardial SPECT in detecting dysfunction of coronary microcirculation. Methods: Forty-eight patients diagnosed with cardiac syndrome X underwent dipyridamole stress 201 Tl myocardial SPECT. Dipyridamole (0.56 mg/kg) was intravenously injected over 4 min followed by 201 Tl (111 MBq) injection at 2 min after dipyridamole administration. Image was acquired at 10 min and 240 min post-injection and co-analyzed by over two experienced doctors in nuclear medicine after three-dimensional reconstruction. The patients with 'reverse redistribution' underwent repeated dipyridamole stress 201 Tl SPECT after medical therapy for 2 weeks. The clinical symptoms and results of the treadmill exercise test pre-and post-therapy were compared. Results: Forty two patients (42/48, 87.50%) showed segmental defects: 'reverse redistribution' on delayed (240 min) 201 Tl images. After medical treatment, 36 cases of the 42 'reverse redistribution' patients had improvement in both clinical symptoms and treadmill exercise test. Post-treatment 201 Tl imaging showed improvement in 45/49 (91.84%) defect segments. Six of the 42 patients had no improvement in clinical symptoms and/or treadmill exercise test. Post-treatment 201 Tl imaging showed no improvement in all the 7 defect segments on the first scan. Conclusion: Dipyridamole stress 201 Tl myocardial SPECT may be valuable in evaluation of impaired coronary microcirculation associated with cardiac syndrome X. (authors)

Quantitative myocardial thallium single-photon emission computed tomography in normal women: demonstration of age-related differences

International Nuclear Information System (INIS)

Cohen, M.; Touzery, C.; Cottin, Y.; Benoit, T.; Athis, P. d'; Roy, S.; Louis, P.; Wolf, J.E.; Rigo, P.; Brunotte, F.

1996-01-01

The aim of this study is the development of a database of normal women for quantitative analysis of exercise and reinjection myocardial single-photon emission computed tomography (SPET). We studied 101 subjects (40 males and 61 females) with less than 5% likelihood of coronary artery disease. All patients underwent stress and rest thallium-201 myocardial SPET. Myocardial stress was induced by bicycle exercise test (n=51), dipyridamole infusion (n=27) or a combined test (n=23). Multivariate ANOVA showed that the type of stress did not influence the percentage of thallium uptake for each region. Significant differences between men and women were found for the percentage of uptake in the inferior and the anterior wall. The most original finding of this study is the correlation between age and thallium uptake in the three regions of the anterior wall, showing an increase in measured thallium uptake with age for women. Consequently, two groups of women, those under and those over 55 years old, were separated, with a significantly lower tracer uptake in the anterior wall in the younger age group. (orig./MG)

A serial changes of thallium-201 myocardial images in a patient with nontransmural myocardial infarction

International Nuclear Information System (INIS)

Tanaka, Takeshi; Itoh, Yukiyoshi; Takayama, Yasuo

1986-01-01

A 66 year old man had suffered from inferior myocardial infarction one year ago and then suffered from effort angina. Recently rest angina attack frequently occurred and he was admitted because of angina attack refractory to TNG. The patient was diagnosed as broad nontransmural infarction. A serial thallium-201 myocardial imagings at rest and thallium-201 lung uptake imagings were performed and some interesting findings were obtained as followings. Myocardial imagings on 3rd day after admission showed no significant deffect, however EF was 34 %. Immediately after severe ischemic attack marked defect was noted at posterolateral region and ECG showed prominent precordial ST depression without accompanying significant ST change in II, III, aVF. On 3rd day after severe attack under hemodynamically and electrocardiographically stable state posterolateral defect improved, though still persisted. EF was 28 %. On 3rd day postop no marked defects were noted in myocardial imagings, so posterolateral defect at rest after severe ischemic attack was proved to be transient defect. In this case thallium-201 lung uptake was not noted before attack. Immediately after severe attack thallium lung uptake increased and maximal uptake was noted at basal zone of lung, however in chest X-P typical butterfly shadow was noted at upper zone of lung. On 3rd day after severe attack hemodynamics improved and butterfly shadow ceased, though thallium lung uptake increased and noted at upper zone of lung. After operation thallium lung uptake improved. (J.P.N.)

Resting technetium-99m methoxyisobutylisonitrile cardiac imaging in chronic coronary artery disease: comparison with rest-redistribution thallium-201 scintigraphy

International Nuclear Information System (INIS)

Cuocolo, A.; Maurea, S.; Pace, L.; Nicolai, E.; Nappi, A.; Imbriaco, M.; Trimarco, B.; Salvatore, M.

1993-01-01

We studied 19 patients with angiographically proven coronary artery disease and left ventricular dysfunction (ejection fraction 33%±8%) by resting technetium-99m methoxyisobutylisonitrile ( 99m Tc-MIBI) and rest-redistribution thallium-201 cardiac imaging. Thallium and 99m Tc-MIBI studies were visually analysed. Of 285 segments, 203 (71%) had normal thallium uptake, 48 (17%) showed reversible thallium defects and 34 (12%) showed irreversible thallium defects. Of these 34 irreversible thallium defects, 19 (56%) were moderate and 15 (44%) were severe. Of the corresponding 285 segments, 200 (70%) had normal 99m Tc-MIBI uptake, while 37 (13%) showed moderate and 48 (17%) showed severe reduction of MIBI uptake. Myocardial segmental agreement for regional uptake score between initial thallium and resting 99m Tc-MIBI images was 90% (κ=0.78). Segmental agreement between delayed thallium and resting 99m Tc-MIBI images was 77% (κ=0.44). In particular, in 26 (9%) segments 99m Tc-MIBI uptake was severely reduced while delayed thallium uptake was normal or only moderately reduced. These data suggest that although rest-redistribution thallium and resting 99m Tc-MIBI cardiac imaging provide concordant results in the majority of myocardial segments, some segments with severely reduced resting 99m Tc-MIBI uptake may contain viable but hypoperfused myocardium. Thus, conclusions on myocardial viability based on 99m Tc-MIBI uptake should be made with caution in chronic coronary artery disease. (orig.)

The safety of dipyridamole myocardial perfusion scintigraphy (MPS) in patients with end-stage chronic airways limitations (CAL)

International Nuclear Information System (INIS)

Roman, M.R.; Freeman, A.P.; Angelides, S.

2000-01-01

Full text: Dipyridamole MPS is a well-established investigative technique in the diagnosis and pre-operative risk stratification of patients with possible coronary artery disease. However, there remains a concern of its use in patients with end-stage chronic airways limitations (CAL). Lung volume reduction surgery (LVRS) is a recent therapeutic option for such patients. The options for non-invasive pre-operative cardiac assessment in such patients are limited. This study reviewed the safety of dipyridamole use in such a clinical setting. 20 patients (10M, 10F, mean age 64.8 yrs) were evaluated. None had any history of ischaemic heart disease. Dipyridamole was administered intravenously at a dose of 0.05 mg/kg. Six patients remained asymptomatic throughout the procedure, while none experienced any chest pain. Two patients experienced moderate dyspnoea, which was rapidly relieved with aminophylline (100mg IV) during the recovery phase of the study. Two others developed mild dyspnoea; one settled spontaneously, while the other responded promptly to aminophylline. Aminophylline was administered to nine other patients to reverse minor symptoms (headache, flushing sensation). One other patient developed marked hypotension (SBP fell >20mmHg) and bradycardia, but no ECG changes for myocardial ischaemia. He responded well to aminophylline. His myocardial perfusion scan demonstrated extensive reversible myocardial ischaemia. Although the population size was small, dipyridamole appears safe to use in patients with end-stage CAL. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

Myocordial perfusion SPECT with dipyridamole stress test in cardiac syndrome X

International Nuclear Information System (INIS)

Czepczynski, R.; Smolarek, I.; Sowinski, J.; Rogacka, D.; Kazmierczak, M.; Wysocki, H.

2006-01-01

Cardiac syndrome X defines patients with typical anginal chest pain, a positive exercise ECG stress test and angiographically normal coronary arteries. Aim of this study was to evaluate the role of myocardial perfusion SPECT with dipyridamole stress in the diagnosis of cardiac syndrome X. Patients, methods: 68 patients with syndrome X aged 32 to 60 years were subjected to myocardial imaging using 99m Tc-MIBI according to the two-days protocol: at rest and after dipyridamole infusion. Semiquantitative evaluation of the images was based on the assessment of 99m Tc-MIBI uptake in 17 myocardial segments using a 5-points scale (0 point - normal uptake, 4 points - no uptake). Scores obtained in each segment were summed up, constituting the summed rest score (SRS) and summed stress score (SSS). Results: mean SRS was 7.9 ± 4.8 and mean SSS was 7.2 ± 4.4 (non-significant difference). Individual comparison of SRS and SSS values revealed three patterns of scintigraphic images: (1) in 25 patients (36.8%), a paradoxical improvement of perfusion at stress images was found, (2) in 23 patients (33.8%), the myocardial perfusion deteriorated after dipyridamole, (3) in 20 patients (29.4%), no significant change of the myocordial perfusion between rest and stress images occurred. Conclusions: in cardiac syndrome X, myocardial SPECT with dipyridamole stress shows different patterns of myocardial perfusion that reflects heterogeneity of this pathology. (orig.)

Dipyridamole cerebral flow stress test evaluating ischemic cerebrovascular diseases

International Nuclear Information System (INIS)

Xiu, Y.; Chen, S.; Sun, X.; Liu, S.; Li, W.; Fan, W.; Wang, X.

2000-01-01

To detect the clinical value of dipyridamole cerebral blood flow stress test in cerebrovascular diseases (CVD). Nineteen patients (9 male, 10 female, mean age=65) who were diagnosed as CVD were included. One suffered from infarct, two suffered from thrombosis, one feel dizziness. All 4 performed rest and stress test. The other 15 were VBI, 9 of them performed stress test. Rest and stress test were done two-day method using Elscint Apex SP-6 SPECT equipped with low energy all purpose collimator. Rest perfusion imaging was started 30 min after injecting 1.11 GBq 99m Tc-ECD. Dipyridamole stress test was done within one week. 0.56 mg/Kg dipyridamole was injected intravenously during 4 min the same dose of ECD was injected 2 min later. The acquisition started 30 min later with the same parameter. Heart rate, ECG and the patient's complaint were monitored 2 min before and after dipyridamole. After correction for attenuation, transverse, coronal and sagittal slices were reconstructed. Eighteen ROIs were drawn symmetrically on cingulate, frontal, temporal-parietal, temporal, occipital, vision cortex, basal ganglia, superior frontal and parietal on the 3 rd , 6 th , 9 th transverse slices, selecting the contralateral as the reference region. The counts per pixel in each ROI were divided by the counts of the mirror region to obtain the relative uptake ratio. We think it abnormality when the ratio is above 1,1 or below 0.9. The sensitivity for rest and stress rCBF test was compared. rCBF was decreased at 10 of 19 patients (sensitivity 52.6%). 14 had low rCBF after dipyridamole (sensitivity 72.3%), Among the patients who studied stress test, 6 had normal rCBF at rest and low rCBF after stress. The abnormal area was enlarged after dipyridamole for 1 patients, 2 improved and 2 unchanged. 8 of 15 VBI had normal rCBF at rest (sensitivity 53.3%). 9 of 15 VBI performed stress test. rCBF was normal at rest for 5 patients, rCBF was decreased after stress, it was improved for one

Tc99m-Tetrofosmin and Thallium-201 SPECT imaging of pituitary tumors: Preliminary results

International Nuclear Information System (INIS)

Yarman, S.; Mudun, A.

2002-01-01

Aim: It has been reported that pituitary adenomas accumulate Thallium -201(Tl-201), Tc99m-sestamibi and In111-Octreotide. These agents maybe useful in the diagnosis and follow-up of pituitary adenomas. Tc99m-tetrofosmin also has been shown as an tumor seeking agent in various tumors. The aim of this study is to evaluate the accumulation of Tc99m-tetrofosmin in pituitary adenomas and compare the results to Tl-201 SPECT. Methods: We performed Tc99m-Tetrofosmin and Tl-201 SPECT imaging on 5 patients (pts) with pituitary tumors, 3 patients with acromegaly, 1 patient with macro prolactinoma, and 1 patient with nonfunctional tumor (1 female, 4 male, age range: 26-50). SPECT imaging of cranium were obtained 20 min after intravenous injection of 111 MBq Tl-201 and 555 MBq Tc99m-Tetrofosmin on different days with a dual head gamma camera. All but one patient had surgical therapy. One patient had medical treatment. One patient had post surgical imaging with both Tetrofosmin and Tl-201 and 2 pts had only with Thallium. Semiquantitative analysis were performed by calculating tumor to background ratio from the mean counts of the created ROI's. Results: All adenomas showed prominent uptake with both Thallium and Tetrofosmin. The mean tumor to background ratios were 2.3 (range: 1.2-4.29) with Thallium and 3.57 (range: 1.6-6.86) with Tetrofosmin. Post therapy images showed no significant uptake in pituitary region with both agents in 2 patients. Post therapy mean Thallium uptake ratio in 3 pts was 1.64. One patient with acromegaly showed no decrease in thallium uptake, but showed some decrease in tetrofosmin uptake. Conclusion: Although our patient number is limited, these preliminary results indicate that Tc99m-tetrofosmin has also strong affinity for pituitary adenomas as does Thallium, either the adenoma is functioning or non-functioning. It may have a potential value to evaluate the response to therapy

Thallium-201 myocardial imaging in evaluation of asymptomatic individuals with ischaemic ST segment depression on exercise electrocardiogram

International Nuclear Information System (INIS)

Caralis, D.G.; Bailey, I.; Kennedy, H.L.; Pitt, B.

1979-01-01

This study showed that asymptomatic adults with normal physical examination, normal resting electrocardiogram, and normal routine laboratory evaluation who had a positive exercise electrocardiogram and abnormal exercise thallium-201 myocardial image had a very high probability of angiographically significant coronary artery disease. If, on the other hand, the exercise electrocardiogram was positive for 'ischaemic' ST segment changes, but the exercise thallium image was normal, the probability for coronary disease was low. The exercise electrocardiogram combined with thallium-201 myocardial image are safe non-invasive methods which can be performed on an out-patient basis. (author)

Evaluation of initial uptake and redistribution on stress thallium-201 myocardial perfusion images in patients with myocardial infarction

International Nuclear Information System (INIS)

Watanabe, Yoshihiko; Tonooka, Ichiroh; Kanaya, Tohru; Tsuiki, Kai; Yasui, Shouji.

1984-01-01

Stress thallium-201 myocardial perfusion imaging was performed on 29 patients with previous myocardial infarction and 29 patients with angina pectoris at exercise to evaluate thallium-201 kinetics in ischemic heart disease. Four views of thallium-201 images (right anterior oblique, antero-posterior, left anterior oblique and left lateral views) were obtained at 5 min after treadmill exercise with administration of 2 mCi of thallium-201 chloride (initial image) and at 3 hours later (delayed image). Myocardial images were divided into 6 segments (anterior, lateral, inferior, posterior, apical and septal segments) and initial uptake (IU) and redistribution index (RDI, the ratio of the maximal washout rate to a washout rate in each segment) were calculated in order to assess the relations of thallium-201 kinetics to wall motion abnormality and coronary artery stenosis. In myocardial infarction, IU and RDI were decreased in proportion to the severity of wall motion abnormality and coronary artery stenosis. Contrarily, in angina pectoris, IU was decreased but RDI was increased proportionally to the severity of coronary arterial stenosis. In conclusion, IU and redistribution of thallium-201 were affected essentially by both the grade of coronary arterial stenosis and the amount of residual viable heart muscle in patients with ischemic myocardial disease. (author)

Rest/exercise thallium myocardial perfusion imaging: a new and rapid technique to evaluate coronary artery disease

International Nuclear Information System (INIS)

Segall, G.M.; Zipkin, R.E.; Stanford Univ., CA

1993-01-01

Twenty-six patients underwent conventional exercise/4-h redistribution thallium myocardial perfusion imaging as well as rest/exercise imaging on different days. For the rest/exercise study, patients were inmaged 10 min after receiving 1 mCi thallium at rest. The resting study was immediately followed by symptom-limited treadmill exercise. Patients were injected with 2 mCi thallium at peak exercise and imaged 10 min later. The entire rest/exercise study was completed in 2 h. There was a high degree of correlation between the two studies. Of the 130 segments analysed, 84 were normal and 46 were abnormal by exercise/redistribution imaging whereas 88 were normal and 42 were abnormal by rest/exercise imaging. Among the 14 patients who had coronary arteriography, both exercise/redistribution and rest/exercise imaging correctly identified 23/35 segments as abnormal (sensitivity [pi003] 66% and 34/35 segments as normal (specificity=97%). Furthermore, abnormal segments were more likely to be reversible on the rest/exercise study. The results suggest that the accuracy of rest/exercise thallium imaging is equal to conventional exercise/redistribution imaging in the evaluation of coronary artery disease. The significant time economy and possible improvement in assessing myocardial viability are important potential advantages of this new technique. (Author)

Cerebral blood flow imaging with thallium-201 diethyldithiocarbamate SPECT

NARCIS (Netherlands)

van Royen, E. A.; de Bruïne, J. F.; Hill, T. C.; Vyth, A.; Limburg, M.; Byse, B. L.; O'Leary, D. H.; de Jong, J. M.; Hijdra, A.; van der Schoot, J. B.

1987-01-01

Thallium-201 diethyldithiocarbamate ([201TI]DDC) was studied in humans as an agent for cerebral blood flow imaging. Brain uptake proved to be complete 90 sec after injection with no appreciable washout or redistribution for hours. Intracarotid injection suggested an almost 100% extraction during the

Evaluation of thallium-201 imaging in nontransmural ischemia and infarction

International Nuclear Information System (INIS)

Haidar, B.; Oldewurtel, H.A.; Moschos, C.B.; Lee, W.K.; Regan, T.J.

1981-01-01

To assess the validity of thallium-201 myocardial imaging in the diagnosis of nontransmural ischemia and infarction, the proximal left anterior descending coronary artery was partially occluded for 60 minutes with a balloon-tip catheter in intact anesthetized dogs in a basal state or during atrial pacing. In vivo scintigrams of myocardium were compared with those obtained in the isolated heart and in the incised ventricle spread flat. None of the animals with partial occlusion with or without pacing demonstrated abnormal scintiscans in vivo. Removal of background by isolating the heart increased positive images to 30%; positive images were associated with an isotope count ratio between ischemic and normal muscle of less than 0.67. Removal of superimposed nonischemic muscle in the heart enface increased image detection after pacing to 11 of 15. Since animals with subendocardial scar failed to demonstrate a cold area in vivo, unfavorable geometry as well as extent and degree of ischemia appear to be important. Thus, thallium radioactivity in superimposed and adjacent myocardium, as well as background, may limit the detection of nontransmural ischemia and scar

Blood conservation with membrane oxygenators and dipyridamole.

Science.gov (United States)

Teoh, K H; Christakis, G T; Weisel, R D; Madonik, M M; Ivanov, J; Wong, P Y; Mee, A V; Levitt, D; Benak, A; Reilly, P

1987-07-01

Cardiopulmonary bypass induces platelet activation and dysfunction, which result in platelet deposition and depletion. Reduced platelet numbers and abnormal platelet function may contribute to postoperative bleeding. A membrane oxygenator may preserve platelets and reduce bleeding more than a bubble oxygenator, and the antiplatelet agent dipyridamole may protect platelets intraoperatively and reduce bleeding postoperatively. A prospective randomized trial was performed in 44 patients undergoing elective coronary artery bypass grafting to assess the effects of the membrane oxygenator and dipyridamole on platelet counts, platelet activation products, and postoperative bleeding. Patients who were randomized to receive a bubble oxygenator and no dipyridamole had the lowest postoperative platelet counts, the greatest blood loss, and the most blood products transfused. Platelet counts were highest and blood loss was least in patients randomized to receive a membrane oxygenator and dipyridamole (p less than .05). A bubble oxygenator with dipyridamole and a membrane oxygenator without dipyridamole resulted in intermediate postoperative platelet counts and blood loss. Arterial thromboxane B2 and platelet factor 4 concentrations were elevated on cardiopulmonary bypass in all groups. Both the membrane oxygenator and dipyridamole were independently effective (by multivariate analysis) in preserving platelets. Optimal blood conservation was achieved with a membrane oxygenator and dipyridamole.

Prognostic value of thallium-201 myocardial perfusion imaging in patients with unstable angina who respond to medical treatment

International Nuclear Information System (INIS)

Brown, K.A.

1991-01-01

Although the prognostic value of thallium-201 imaging is well established, its ability to risk stratify patients who present with unstable angina is unclear. Fifty-two consecutive patients admitted with unstable angina who responded to medical treatment and underwent stress thallium-201 imaging within 1 week of discharge were studied. Patients were followed up for 39 +/- 11 months. Cardiac events included cardiac death (n = 3), nonfatal myocardial infarction (n = 4) and admission for unstable angina or revascularization (n = 17). The ability of thallium-201 data (redistribution, fixed defects, normal) to predict cardiac events was compared with clinical data (age, gender, prior myocardial infarction, anginal syndrome, rest and stress electrocardiogram) and cardiac catheterization data using logistic regression. Thallium-201 redistribution was the only significant predictor of cardiac death or nonfatal myocardial infarction (p less than 0.05). The number of myocardial segments with thallium-201 redistribution (p less than 0.0005) and a history of prior myocardial infarction (p less than 0.05) were the only significant predictors of all cardiac events. Cardiac death or nonfatal myocardial infarction occurred more frequently in patients with thallium-201 redistribution (6 [26%] of 23) than in those without redistribution (1 [3%] of 29, p less than 0.05). Similarly, total cardiac events developed more frequently in patients with thallium-201 redistribution (p less than 0.001). Stress thallium-201 imaging has important prognostic value in patients admitted with unstable angina who respond to medical therapy and can identify subgroups at high versus low risk for future cardiac events

Thallium-201 myocardial perfusion imaging during transient coronary occlusion at the time of PTCA

International Nuclear Information System (INIS)

Nakagawa, Tatsuya; Sugihara, Hiroki; Inagaki, Suetsugu

1989-01-01

To evaluate myocardial perfusion during transient coronary arterial occlusion, thallium-201 was administered intravenously during percutaneous transluminall coronary angioplasty (PTCA) in 12 patients with effort angina, and the resulting perfusion images were compared with those of exercise stress obtained before PTCA. Thallium-201 was injected at the last inflation of an angioplastic baloon and occlusion was maintained for 60 to 90 sec. Three projections of planar images were obtained immediately after PTCA, using a portable gamma camera in an angiography room. These perfusion images obtained during PTCA and exercise were visually interpreted and compared. Myocardial perfusion defects due to the responsible vessel occlusion were observed at early imaging after PTCA, and were fully redistributed three hrs post injection. In 10 patients without angiographically imaged collateral vessels, there were no significatn differences in perfusion between images during PTCA and during exercise. Two patients whose collaterals were observed during coronary angiography before PTCA had higher perfusion scores during PTCA than during exercise. We concluded that intravenous injection of thallium-201 during PTCA is a useful means for assessing alteration of myocardial perfusion due to transient coronary occlusion without increasing the risk of angioplastic procedures, and that it provides more precise information about the jeopardized myocardium, perfused by antegrade blood flow. (author)

The pacing stress test: thallium-201 myocardial imaging after atrial pacing. Diagnostic value in detecting coronary artery disease compared with exercise testing

International Nuclear Information System (INIS)

Heller, G.V.; Aroesty, J.M.; Parker, J.A.; McKay, R.G.; Silverman, K.J.; Als, A.V.; Come, P.C.; Kolodny, G.M.; Grossman, W.

1984-01-01

Many patients suspected of having coronary artery disease are unable to undergo adequate exercise testing. An alternate stress, pacing tachycardia, has been shown to produce electrocardiographic changes that are as sensitive and specific as those observed during exercise testing. To compare thallium-201 imaging after atrial pacing stress with thallium imaging after exercise stress, 22 patients undergoing cardiac catheterization were studied with both standard exercise thallium imaging and pacing thallium imaging. Positive ischemic electrocardiographic changes (greater than 1 mm ST segment depression) were noted in 11 of 16 patients with coronary artery disease during exercise, and in 15 of the 16 patients during atrial pacing. One of six patients with normal or trivial coronary artery disease had a positive electrocardiogram with each test. Exercise thallium imaging was positive in 13 of 16 patients with coronary artery disease compared with 15 of 16 patients during atrial pacing. Three of six patients without coronary artery disease had a positive scan with exercise testing, and two of these same patients developed a positive scan with atrial pacing. Of those patients with coronary artery disease and an abnormal scan, 85% showed redistribution with exercise testing compared with 87% during atrial pacing. Segment by segment comparison of thallium imaging after either atrial pacing or exercise showed that there was a good correlation of the location and severity of the thallium defects (r . 0.83, p . 0.0001, Spearman rank correlation). It is concluded that the location and presence of both fixed and transient thallium defects after atrial pacing are closely correlated with the findings after exercise testing

Dipyridamole induced directory disfunction of infarcted vessel, and estimation of patients with acute myocardial infarction and successful PTCA

International Nuclear Information System (INIS)

Hashimoto, Yasunori; Yamabe, Hiroshi; Kim, Sushik; Yano, Takashi; Fujita, Hideki; Kakimoto, Tetsuya; Namura, Hiroyuki; Maeda, Kazumi; Yokoyama, Mitsuhiro

1993-01-01

The purpose of this study was to determine whether transient disturbance of vascular dilation in the peripheral coronary vessels in patients with myocardial infarction in whom coronary recanalization was successfully attained in the acute stage. The subjects were 6 patients with acute myocardial infarction in whom recanalization was successfully attained without a significant coronary stenosis by emergency percutaneous transluminal coronary angioplasty (PTCA). Dipyridamole-loaded thallium-201 myocardial scintigraphy was undertaken during the acute stage (an average of 5 days after PTCA) and during convalescent stage (an average 24 days after PTCA). Defect was seen in the infarcted areas on early images during the acute stage in all 6 patients, and Tl uptake in the infarcted areas was improved during the convalescent stage in 2 of the 6 patients. In these two patients, fill-in phenomenon was seen in the infarcted area during acute stage when images were acquired after re-injection of Tl-201. These findings suggested that transient disturbance of vascular dilation may occur in the peripheral coronary artery vessels in the infarcted area where recanalization was successfully attained in patients with acute myocardial infarction. (N.K.)

Intracoronary thallium-201 scintigraphy after thrombolytic therapy for acute myocardial infarction compared with 10 and 100 day intravenous thallium-201 scintigraphy

International Nuclear Information System (INIS)

Heller, G.V.; Parker, J.A.; Silverman, K.J.; Royal, H.D.; Kolodny, G.M.; Paulin, S.; Braunwald, E.; Markis, J.E.

1987-01-01

Thallium-201 imaging has been utilized to estimate myocardial salvage after thrombolytic therapy for acute myocardial infarction. However, results from recent animal studies have suggested that as a result of reactive hyperemia and delayed necrosis, thallium-201 imaging may overestimate myocardial salvage. To determine whether early overestimation of salvage occurs in humans, intracoronary thallium-201 scans 1 hour after thrombolytic therapy were compared with intravenous thallium-201 scans obtained approximately 10 and 100 days after myocardial infarction in 29 patients. In 10 patients with angiographic evidence of coronary reperfusion, immediate improvement in thallium defects and no interim clinical events, there was no change in imaging in the follow-up studies. Of nine patients with coronary reperfusion but no initial improvement of perfusion defects, none showed worsening of defects in the follow-up images. Six of these patients demonstrated subsequent improvement at either 10 or 100 days after infarction. Seven of 10 patients with neither early evidence of reperfusion nor improvement in perfusion defects had improvement of infarct-related perfusion defects, and none showed worsening. In conclusion, serial scanning at 10 and 100 days after infarction in patients with no subsequent clinical events showed no worsening of the perfusion image compared with images obtained in acute studies. Therefore, there is no evidence that thallium-201 imaging performed early in patients with acute myocardial infarction overestimates improvement

Extraction and myocardial distribution of IPBDA potentials of lipophylic cations for use as thallium substitutes

International Nuclear Information System (INIS)

Rigo, P.; Woo, D.V.; Tanaka, T.; Wong, D.F.; Dannals, R.; Wagner, H.N. Jr.; Becker, L.C.

1984-01-01

Potassium analogs have been used for several years as clinical indicators of myocardial blood flow, but the value of thallium is limited by its long half life and low energy photons. We have tested 4-iodiphenylbenzyldimethylammonium (IPBDA) a radio-iodinated cation as a potential thallium substitute in a series of 7 mongrel dogs. First pass myocardial and systemic extraction were determined using the double tracer technique, with technetium albumin as reference. Tissue iodine 125 IPBDA distributions were compared to microspheres under a variety of pathophysiological conditions (control, myocardial infarction, coronary artery stenosis, Dipyridamole infusion). First pass extraction averaged 73% in normal controls (3 determinations), 66.1% in dogs with LAD occlusion (4 determination) and 40.1% in dogs receiving persantine (with or without coronary stenosis or occlusion) (5 determinations). Tissue microspheres and IPBDA distribution correlated in each dog (r=.75, to .85) but the relationship was not linear, IPBDA underestimating myocardial blood flow at high flow. Iodinated IPBDA is a potential thallium substitute due to the better physical characteristics of iodine 123. It shares however the biological limitations of potassium and analogs: a variable extraction and a non linear relation to flow. (Author)

Arm exercise-thallium imaging testing for the detection of coronary artery disease

International Nuclear Information System (INIS)

Balady, G.J.; Weiner, D.A.; Rothendler, J.A.; Ryan, T.J.

1987-01-01

Patients with lower limb impairment are often unable to undergo a standard bicycle or treadmill test for the evaluation of coronary artery disease. To establish an alternative method of testing, 50 subjects (aged 56 +/- 10 years) performed arm ergometry testing in conjunction with myocardial thallium scintigraphy. All underwent coronary angiography; significant coronary artery disease (greater than or equal to 70% stenosis) in at least one vessel was present in 41 (82%) of the 50 patients. Thallium scintigraphy was found to have an 83% sensitivity and 78% specificity for detecting coronary disease, compared with a sensitivity and specificity of 54% (p less than 0.01) and 67% (p = NS), respectively, for exercise electrocardiography. In the subgroup of 23 patients who had no prior myocardial infarction or left bundle branch block and were not taking digitalis, thallium scintigraphy had a sensitivity of 80% versus 50% for exercise electrocardiography. Scintigraphy yielded a sensitivity of 84, 74 and 90% for one, two and three vessel disease, respectively. Noninvasive arm ergometry exercise-thallium imaging testing appears to be reliable and useful and should be considered in the evaluation of coronary artery disease in patients with lower limb impairment

Comparison of 18F-FDG PET and 201 thallium chloride SPECT in the evaluation of cerebral glioma prior to surgery

International Nuclear Information System (INIS)

Poon, A.M.T.; Cher, L.; Berlangieri, S.U.; Fabinyi, G.; Tochon-Danguy, H.; Chan, J.G.; Scott, A.M.

2000-01-01

Full text: The purpose of the study was to compare the accuracy of 18 F-FDG PET and 201 Tl SPECT in detecting and grading primary cerebral glioma through comparison to surgical pathology. A total of 33 patients with primary cerebral glioma had 35 18 F-FDG PET/ 201 Tl SPECT scans prior to surgery. Pre-operative 18 F -FDG PET and 201 Tl SPECT studies were reviewed and compared with histologic tumour grade. Radiological comparisons were also performed when pre-operative studies were available. 17/18 patients with glioblastoma multiforme demonstrated hypermetabolic lesions on 18 F-FDG PET scan and increased thallium uptake on SPECT scan. Increased 18 F -FDG and thallium uptake were also demonstrated in patients with anaplastic astrocytoma, gemistocytic astrocytoma, and one biopsy which was difficult to grade because of small biopsy sample and co-existing radiation necrosis. In general, low grade gliomas had reduced 18 F -FDG uptake and normal thallium uptake (6/7, where two patients had tumour with hypermetabolic and hypometabolic regions). MRI correctly identified 4/7 patients with low to intermediate grade glioma. Pilocytic astrocytoma, protoplastic astrocytoma and oligoastrocytoma all demonstrated hypometabolic PET activity and normal thallium uptake. In conclusion, 18 F-FDG PET and 201 Tl SPECT are very sensitive in pre-operative prediction of high grade glioma. In low grade tumour, 201 Tl SPECT appeared to be less useful in the absence of breakdown of the blood brain barrier. MR imaging accurately identified the presence of tumour but was less accurate in determining the grade of tumour. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

Diagnostic value for coronary artery disease of ST depression and chest pain during dipyridamole loading

International Nuclear Information System (INIS)

Yonezawa, Yoshihiro; Doi, Yoshinori; Aono, Tadashi; Odawara, Hiroaki; Chikamori, Taishiro; Yamada, Mitsutoshi; Takata, Jun; Ozawa, Toshio; Hamashige, Naohisa.

1991-01-01

The diagnostic significance of both ST depression and chest pain during dipyridamole loading was assessed in 437 patients with coronary artery disease (CRD) who have received dipyridamole-loading thallium-201 myocardial scintigraphy and coronary arteriography. ST depression and chest pain were induced in 35% and 42%, respectively. ST depression occurred in 23% for one vessel disease, 55% for two-vessel disease, 67% for three-vessel disease, and 11% for non-significant disease. In the absence of myocardial infarction, it occurred in as many as 78% for two-vessel disease and 94% for three-vessel disease. ST depression had a sensitivity of 51% and a specificity of 89%. Chest pain had a lower specificity (77%), whereas the sensitivity remained the same (51%). In 42 (31%) of 134 patients with ST depression, coronary revascularization was necessary in the early stage. With a median follow up of 29 months, 3 patients (2%) died of cardiac events, and 12 (9%) had nonfatal cardiac complications. There was a significant correlation between reversible defects (RD) on myocardial scintigrams and ST depression; RD were seen in 81% of ST depression cases, and ST depression occurred in 51% of 210 RD cases. The more diseased vessels, the more frequently ST depression occurred in accordance with RD on myocardial scintigrams. Both ST depression and chest pain during dipyridamole loading tended to be associated with myocardial ischemia, suggesting the diagnostic value in CRD patients with limited exercise loading. RD on myocardial scintigrams was considered attributable to coronary steal phenomenon for multi-vessel disease and to the difference in the relative increase of the coronary flow for single vessel disease. (N.K.)

Evaluation of myocardial involvement in Duchenne progressive muscular dystrophy with thallium-201 myocardial perfusion imaging

International Nuclear Information System (INIS)

Kawai, Naoki; Yamamoto, Shuhei; Okada, Mitsuhiro

1983-01-01

Myocardial involvement in progressive muscular dystrophy of the Duchenne type was evaluated in 19 patients using thallium-201 myocardial perfusion imaging. The qualitative analysis was performed in anterior, 3 left anterior oblique and left lateral projection images by three experienced physicians. Distinct perfusion defects were shown in 13 patients, especially in LV posterolateral or posterior walls (11 patients). There was no significant relationship between the presence of perfusion defects and the skeletal muscle changes or thoracic deformities assessed by transmission computed tomography. Slightly increased thallium-201 activity in RV free wall and lungs was shown in nine and one patient, respectively. The extensive perfusion defects were shown in 2 patients who died of congestive heart failure 1 to 2 years after the scintigraphic study. The myocardial scintigraphic changes were considered to be minimal in 7 of 9 patients who underwent two serial scintigraphic studies in 2 to 3 years. It was concluded that the thallium myocardial perfusion imaging was a useful clinical technique to evaluate the cardiomyopathy in Duchenne progressive muscular dystrophy. (author)

Evaluation of myocardial involvement in Duchenne progressive muscular dystrophy with thallium-201 myocardial perfusion imaging

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Kawai, Naoki; Yamamoto, Shuhei; Okada, Mitsuhiro (Nagoya Univ. (Japan). Faculty of Medicine)

1983-12-01

Myocardial involvement in progressive muscular dystrophy of the Duchenne type was evaluated in 19 patients using thallium-201 myocardial perfusion imaging. The qualitative analysis was performed in anterior, 3 left anterior oblique and left lateral projection images by three experienced physicians. Distinct perfusion defects were shown in 13 patients, especially in LV posterolateral or posterior walls (11 patients). There was no significant relationship between the presence of perfusion defects and the skeletal muscle changes or thoracic deformities assessed by transmission computed tomography. Slightly increased thallium-201 activity in RV free wall and lungs was shown in nine and one patient, respectively. The extensive perfusion defects were shown in 2 patients who died of congestive heart failure 1 to 2 years after the scintigraphic study. The myocardial scintigraphic changes were considered to be minimal in 7 of 9 patients who underwent two serial scintigraphic studies in 2 to 3 years. It was concluded that the thallium myocardial perfusion imaging was a useful clinical technique to evaluate the cardiomyopathy in Duchenne progressive muscular dystrophy.

Exercise thallium-201 imaging in complete left bundle branch block and the prevalence of septal perfusion defects

International Nuclear Information System (INIS)

Jazmati, B.; Sadaniantz, A.; Emaus, S.P.; Heller, G.V.

1991-01-01

To determine the prevalence of septal defects in a generalized referral population, the records of 93 consecutive patients with complete left bundle branch block (BBB) who underwent symptom-limited treadmill exercise testing with thallium-201 myocardial imaging over a 3-year period were reviewed. Segmental analysis of the planar thallium-201 images was performed in a blinded fashion with agreement by consensus. Computerized quantitative analysis of the images also was independently performed, and was correlated with the visual interpretations. Forty-seven patients (51%) had normal images, and 46 (49%) had defects of greater than or equal to 2 segments. In the abnormal studies, only 13 patients (14% of the total population) had septal defects, while a much higher number of patients, 33 (39%), had inferior or apical defects, or both. Coronary angiography was performed in 6 patients with septal defects: Significant narrowing of the left anterior descending coronary artery was found in 4 patients, a narrowed right coronary artery was found in 1, and normal coronary arteries were seen in the other patient. In conclusion, whereas previous studies have suggested a high percentage of false-positive septal defects in patients with left BBB, this study demonstrates a low prevalence (14%) of septal defects in a large population of unselected patients presenting for exercise thallium-201 imaging. Therefore, exercise thallium-201 imaging remains a useful procedure for evaluating patients with complete left BBB

Thallium 201 scintigraphy of the myocardium. A bibliographical survey for image optimisation

International Nuclear Information System (INIS)

Chatelier, Luc.

1979-01-01

At the request of a Nuclear Medicine Service we compiled a review of the literature on thallium 201 myocardium scintigraphy in order to define the optimum parameters for image acquisition; included also are the bibliograhical references of studies on the sensitivities, specificities and accuracies of this technique as compared with electrocardiography in the diagnosis and evaluation of ischemic heart diseases. This examination seems to have a part to play at all stages in the evaluation of ischemic heart diseases, whether for the detection (ischemia) emergency handling (thrombosis) or post-surgical checking (permeability of an aorto-coronary transplant) of these diseases, the great frequency and gravity of which have no longer to be proved. This study covers the whole period since thallium scintigraphy began (1970) until June 1978. Thallium seems to have a great future in cardiology and may be even in other fields since its use is quoted (in only a few publications as yet) for brain, kidney and pancreas scintigraphy [fr

Simultaneous maximal exercise radionuclide angiography and thallium stress perfusion imaging

International Nuclear Information System (INIS)

Narahara, K.A.; Mena, I.; Maublant, J.C.; Brizendine, M.; Criley, J.M.

1984-01-01

Gold-195m is a new ultra-short-lived radionuclide that can be used for cardiac studies. Accurate, reproducible ejection fraction and ventricular wall motion studies can be obtained from first-transit angiography using commercially available imaging and image-processing equipment. The short half-life of gold-195m (30.5 seconds) makes simultaneous dual isotope imaging possible and substantially reduces the radiation exposure from the isotope angiography. The feasibility and possible benefits of performing dual radionuclide studies were evaluated during a single exercise stress test in 24 subjects with known coronary artery disease (CAD) and in 20 normal volunteers. High-quality first-transit angiograms were obtained in all subjects. An 83% sensitivity and 95% specificity for detecting CAD with thallium-201 imaging was noted in this investigation, suggesting that its diagnostic accuracy was not altered by simultaneous dual isotone imaging. When segmental left ventricular (LV) wall motion was compared with thallium-201 perfusion imaging, divergent results were noted in 15 of 44 subjects. An analysis of the ejection fraction (EF) results at rest and stress provided additional information that could be useful in assessing the clinical significance of such differences in segmental wall motion and perfusion. Simultaneous dual isotope imaging appears to be appropriate for situations in which both LV perfusion and function require evaluation. The use of gold-195m allows such information to be obtained from a single exercise test and can thereby reduce the cost and time required for noninvasive evaluations of patients for CAD

Assessment of myocardial viability by dynamic tomographic iodine 123 iodophenylpentadecanoic acid imaging: comparison with rest-redistribution thallium 201 imaging.

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Iskandrian, A S; Powers, J; Cave, V; Wasserleben, V; Cassell, D; Heo, J

1995-01-01

This study examined the ability of dynamic 123I-labeled iodophenylpentadecanoic acid (IPPA) imaging to detect myocardial viability in patients with left ventricular (LV) dysfunction caused by coronary artery disease. Serial 180-degree single-photon emission computed tomographic (SPECT) images (five sets, 8 minutes each) were obtained starting 4 minutes after injection of 2 to 6 mCi 123I at rest in 21 patients with LV dysfunction (ejection fraction [EF] 34% +/- 11%). The segmental uptake was compared with that of rest-redistribution 201Tl images (20 segments/study). The number of perfusion defects (reversible and fixed) was similar by IPPA and thallium (11 +/- 5 vs 10 +/- 5 segments/patient; difference not significant). There was agreement between IPPA and thallium for presence or absence (kappa = 0.78 +/- 0.03) and nature (reversible, mild fixed, or severe fixed) of perfusion defects (kappa = 0.54 +/- 0.04). However, there were more reversible IPPA defects than reversible thallium defects (7 +/- 4 vs 3 +/- 4 segments/patient; p = 0.001). In 14 patients the EF (by gated pool imaging) improved after coronary revascularization from 33% +/- 11% to 39% +/- 12% (p = 0.002). The number of reversible IPPA defects was greater in the seven patients who had improvement in EF than in the patients without such improvement (10 +/- 4 vs 5 +/- 4 segments/patient; p = 0.075). 123I-labeled IPPA SPECT imaging is a promising new technique for assessment of viability. Reversible defects predict recovery of LV dysfunction after coronary revascularization.

Additional diagnostic value of systolic dysfunction induced by dipyridamole stress cardiac magnetic resonance used in detecting coronary artery disease.

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Husser, Oliver; Bodí, Vicente; Sanchís, Juan; Mainar, Luis; Núñez, Julio; López-Lereu, María P; Monmeneu, José V; Ruiz, Vicente; Rumiz, Eva; Moratal, David; Chorro, Francisco J; Llácer, Angel

2009-04-01

Dipyridamole stress perfusion cardiovascular magnetic resonance (CMR) is used to detect coronary artery disease (CAD). However, few data are available on the diagnostic value of the systolic dysfunction induced by dipyridamole. This study investigated whether the induction of systolic dysfunction supplements the diagnostic information provided by perfusion imaging in the detection of CAD. Overall, 166 patients underwent dipyridamole CMR and quantitative coronary angiography, with CAD being defined as a stenosis > or =70%. Systolic dysfunction at rest, systolic dysfunction with dipyridamole, induced systolic dysfunction, and stress first-pass perfussion deficit (PD) and delayed enhancement were quantified. In the multivariate analysis, PD (hazard ratio [HR]=1.6; 95% confidence interval [CI], 1.33-1.91;Pstatistic for predicting CAD (0.81 vs. 0.87; P=.02). Combining induced systolic dysfunction with perfusion imaging increases the diagnostic accuracy of detecting CAD and enables patients with severe ischemia and a high probability of CAD to be identified.

The usefulness of preoperative exercise stress myocardial single photon emission CT with thallium-201 to predict the responses to coronary revascularization

International Nuclear Information System (INIS)

Narita, Michihiro; Kurihara, Tadashi; Murano, Kenichi; Usami, Masahisa; Minamino, Takazoh; Katoh, Osamu; Higashino, Yorihiko.

1989-01-01

To evaluate the usefulness of preoperative exercise stress (Ex) myocardial single photon emission CT (SPECT) with thallium-201 to predict the responses to coronary revascularization (CRV), Ex-SPECT's were obtained in 42 patients with coronary artery disease (CAD). In 34 patients angioplasty was performed and in 18 patients coronary bypass surgery was undergone. Before and after CVR, Ex-SPECT's were obtained both at immediately after Ex (Initial) and 3 hours later (RD) by the rotating gamma camera. Initial images before CRV showed definite perfusion defects (+3) in 76 myocardial segments. Perfusion abnormalities at RD images were graded into (+3 to 0) by visual interpretation. '+3' indicated fixed defect and '0' indicated no perfusion abnormality. At RD images 17 segments showed fixed defect and 59 segments showed improved perfusion more than one grade. After CRV, all 59 segments with improved perfusion at RD images showed improvement of perfusion in comparison with initial images before CRV. Out of 17 segments with fixed defect before CRV, 14 segments showed perfusion defect with +3, while 3 segments showed improved perfusion after CRV. These 3 segments had ECG evidence of myocardial infarction. In these 3 segments, Ex-SPECT's before CRV showed abnormally low myocardial Tl washout rate (WOR) despite they indicated fixed defect visually. On the contrary, other 14 segments with fixed defect showed normal WOR before CRV. In conclusion, visually interpreted Ex-SPECT's before CRV predict the myocardial perfusion after CRV in most of cases. In a small number (especially infarction segments) Ex-SPECT's before CRV cannot predict the improvement of myocardial perfusion after CRV by visual inspection, but WOR abnormality before CRV is useful to prospect their results. (author)

Peritoneal fluid causing inferior attenuation on SPECT thallium-201 myocardial imaging in women

International Nuclear Information System (INIS)

Rab, S.T.; Alazraki, N.P.; Guertler-Krawczynska, E.

1988-01-01

On SPECT thallium images, myocardial left ventricular (LV) anterior wall attenuation due to breast tissue is common in women. In contrast, in men, inferior wall counts are normally decreased compared to anterior counts. The purpose of this report is to describe cases of inferior wall attenuation of counts in women caused by peritoneal fluid, not myocardial disease. Twelve consecutive SPECT thallium myocardial studies performed in women on peritoneal dialysis, being evaluated for kidney transplant, were included in this study. For all studies, 3.5 mCi 201Tl were injected intravenously. Thirty-two images were acquired over 180 degrees (45 degrees RAO progressing to 45 degrees LPO) at 40 sec per stop. SPECT images were reviewed in short axis, horizontal long and vertical long axes. Data were also displayed in bullseye format with quantitative comparison to gender-matched normal files. Ten of 12 female patients studied had inferior wall defects on images, confirmed by bullseye display. All patients had approximately 2 liters of peritoneal fluid. Review of planar rotational views showed diaphragm elevation and fluid margin attenuations affecting left ventricular inferior wall. Thus, peritoneal fluid is a cause of inferior attenuation on 201Tl cardiac imaging

Comparison of dobutamine-stress magnetic resonance imaging and dipyridamole-Tl-201-SPECT as alternative strategies for the detection of coronary artery disease in patients not suitable for stress-echocardiography

International Nuclear Information System (INIS)

Schmidt, M.; Theissen, P.; Voth, E.; Schicha, H.; Jochims, M.; Baer, F.M.; Crnac, J.; Schneider, C.A.; Erdmann, E.

2001-01-01

Aim: During the past decade stress-echocardiography has gained increasing popularity for detection of myocardial ischemia in patients with coronary artery disease. However, about 10% to 15% of the patients submitted for stress-echocardiography do not have an adequate acoustic window. The purpose of this study was to compare high-dose dobutamine-stress magnetic resonance imaging (dobutamine-MRI) with dipyridamole-Tl-201-SPECT (dipyridamole-SPECT) as alternative strategies for detection of myocardial ischemia in patients with inadequate image quality by stress-echocardiography. Patients and Methods: Of 296 patients which were consecutively submitted to stress-echo-cardiography 45 patients (15%) had two or more segments that could not be evaluated according to the 16-segment-model of the American Society of Echocardiography. They underwent dobutamine-MRI and dipyridamole-SPECT studies, which were evaluated using a 28-segment modell. Myocardial segments were attributed to perfusion territories of the coronary arteries. The results of ischemia detection were compared to the results of coronary angiography (stenosis ≥50%). Results: In comparison to coronary angiography dobutamine-MRI yielded a sensitivity of 87%, a specificity of 86%, a positive predictive value of 93%, a negative predictive value of 75% and a diagnostic accuracy of 86%. For dipyridamole-SPECT results were 90%, 86%, 93%, 80% and 89%, respectively. These values were not significantly different. Conclusions: In patients not suitable for stress-echocardiography, both dobutamine-MRI and dipyridamole-SPECT are reliable strategies for detection of myocardial ischemia. Selection is dependent on the patient criteria, technical considerations, local logistics and experience of the observer. (orig.) [de

Assessment of the significance of coronary collateral vessel by using thallium-201 myocardial imaging

International Nuclear Information System (INIS)

Kanoh, Yasushi; Shiotani, Hideyuki; Fukuzaki, Hisashi; Maeda, Kazumi.

1988-01-01

For functional assessment of coronary collateral vessels, twenty-three patients with effort angina pectoris who had total coronary obstruction were studied. The patients were divided depending on the degree of development of collateral vessels into two groups, i.e. good collateral group I (n = 13) and poor collateral group II (n = 10). Thallium-201 scan was performed immediately (Ex-1 image), 20 minutes (Ex-2 image) after exercise and after nitroglycerin administration (NTG image) respectively. In all images, the relative percent activity of thallium-201 in the collateral-dependent ischemic area to the normal myocardium were calculated and were compaired between two groups. Relative percent activities in group I and II were as follows : Ex-1 image ; 75.8 ± 3.5 % vs. 77.2 ± 2.9 % (NS), Ex-2 images ; 85.3 ± 4.5 % vs. 79.3 ± 3.9 % (p < 0.005), NTG image ; 97.3 ± 3.1 % vs. 96.4 ± 5.2 % (NS). From these results, it was elucidated that good collateral induced early partial redistribution in its perfusion area, suggesting that good collateral circulation may provide rapid recovery from myocardial ischemia. (author)

Comparison of oral and intravenous routes of administration of dipyridamole for thallium imaging of type I diabetics with end-stage renal disease

International Nuclear Information System (INIS)

Boudreau, R.J.; Stony, J.T.; du Cret, R.P.; Kuni, C.C.; Wang, Y.; Wilson, R.F.; Schwartz, J.F.; Castaneda-Zuniga, W.R.

1989-01-01

The authors have frequently seen myocardial infarction after renal transplantation in patient with type I diabetes, and treadmill T1-201 testing in these patients have been inadequate. The authors evaluated dipyridamole (DP) as a substitute for treadmill stress. Because intravenous DP was not approved in the United States at the time of the study, the oral formulation wax used for some patients. The authors have prospectively evaluated 80 uremic diabetics (40 received oral T1-201; 40 received intravenous T1-201). Angiogram and scan observers were blinded. There was not difference in the accuracy of the two routes of administration. Pooling the data gave a sensitivity of 86% and a specificity of 79%. However, their disease prevalence was high (52%), which precluded the use of any screening test. The authors now have recommended angiography for these patients

Platelet adhesion studies on dipyridamole coated polyurethane surfaces

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Aldenhoff Y. B.J.

2003-06-01

Full Text Available Surface modification of polyurethanes (PUs by covalent attachment of dipyridamole (Persantinregistered is known to reduce adherence of blood platelets upon exposure to human platelet rich plasma (PRP. This effect was investigated in further detail. First platelet adhesion under static conditions was studied with four different biomaterial surfaces: untreated PU, PU immobilised with conjugate molecule 1, PU immobilised with conjugate molecule 2, and PU immobilised with conjugate molecule 3. In PU immobilised with 1 dipyridamole is directly linked to the surface, in PU immobilised with 2 there is a short hydrophilic spacer chain in between the surface and the dipyridamole, while conjugate molecule 3 is merely the spacer chain. Scanning electron microscopy (SEM was used to characterise platelet adhesion from human PRP under static conditions, and fluorescence imaging microscopy was used to study platelet adhesion from whole blood under flow. SEM experiments encompassed both density measurements and analysis of the morphology of adherent platelets. In the static experiments the surface immobilised with 2 showed the lowest platelet adherence. No difference between the three modified surfaces emerged from the flow experiments. The surfaces were also incubated with washed blood platelets and labeled with Oregon-Green Annexin V. No capture of Oregon-Green Annexin V was seen, implying that the adhered platelets did not expose any phosphatidyl serine at their exteriour surface.

Transient coronary vasodilatory impairment after direct PTCA in acute myocardial infarction

International Nuclear Information System (INIS)

Yamabe, Hiroshi; Kim, Susik; Hashimoto, Yasunori; Fujita, Hideki; Yano, Takashi; Iwahashi, Masanori; Maeda, Kazumi; Yokoyama, Mitsuhiro

1995-01-01

To determine whether transient impairment in coronary artery reserve may occur after acute percutaneous transluminal coronary angioplasty (PTCA) and may be related with myocardial stunning in acute myocardial infarction (MI), 14 paients were examined by dipyridamole (dip) thallium-201 scintigraphy. Of these patients, 13 patients had recanalization after PTCA and one had spontaneous recanalization. Eight and 6 patients were classified as the 'fill-in phenomenon' and as no 'fill-in phenomenon', respectively, on reinjection thallium-201 images after delayed imaging. In the group of 'fill-in phenomenon', thallium uptake was significantly increased both on early images in chronic MI and on reinjection images, as compared with that on early images in acute MI. In the group of 'no fill-in phenomenon', on the contrary, thallium uptake was significantly decreased. An increase of thallium-201 uptake from early images in acute MI to reinjection images was positively correlated with changes in thallium-201 uptake on early images from acute to chronic MI. There was a positive correlation between the arteriographic improvement of wall motion abnormality in the infart zones and % thallium-201 uptake. These data indicate that transient functional impairment may occur not only in the myocardium but also in coronary fine vessels in MI patients successfully treated with direct PTCA. (N.K.)

Quantitative thallium-201 myocardial imaging in assessing right ventricular pressure in patients with congenital heart defects

International Nuclear Information System (INIS)

Rabinovitch, M.; Fischer, K.C.; Treves, S.

1981-01-01

Thallium-201 myocardial scintigraphy was performed in patients with congenital heart defects to determine whether, by quantification of right ventricular isotope uptake, one could assess the degree of right ventricular hypertrophy and so predict the level of right ventricular pressure. It is shown that quantitative analysis of myocardial imaging with thallium-201 is of use clinically in patients with congenital heart defects, in assessing the severity of pulmonary stenosis or the presence of pulmonary artery hypertension. (author)

Thallium kinetics in rat cardiac transplant rejection

International Nuclear Information System (INIS)

Barak, J.H.; LaRaia, P.J.; Boucher, C.A.; Fallon, J.T.; Buckley, M.J.

1988-01-01

Cardiac transplant rejection is a very complex process involving both cellular and vascular injury. Recently, thallium imaging has been used to assess acute transplant rejection. It has been suggested that changes in thallium kinetics might be a sensitive indicator of transplant rejection. Accordingly, thallium kinetics were assessed in vivo in acute untreated rat heterotopic (cervical) transplant rejection. Male Lewis rats weighing 225-250 g received heterotopic heart transplants from syngeneic Lewis rats (group A; n = 13), or allogeneic Brown Norway rats (group B; n = 11). Rats were imaged serially on the 2nd and the 7th postoperative days. Serial cardiac thallium content was determined utilizing data collected every 150 sec for 2 hr. The data were fit to a monoexponential curve and the decay rate constant (/sec) derived. By day 7 all group B hearts had histological evidence of severe acute rejection, and demonstrated decreased global contraction. Group A hearts showed normal histology and contractility. However, thallium uptakes and washout of the two groups were the same. Peak thallium uptake of group B was +/- 3758 1166 counts compared with 3553 +/- 950 counts in the control group A (P = 0.6395); The 2-hr percentage of washout was 12.1 +/- 1.04 compared with 12.1 +/- 9.3 (P = 1.0000); and the decay constant was -0.00002065 +/- 0.00001799 compared with -0.00002202 +/- 0.00001508 (P = 0.8409). These data indicate that in vivo global thallium kinetics are preserved during mild-to-severe acute transplant rejection. These findings suggest that the complex cellular and extracellular processes of acute rejection limit the usefulness of thallium kinetics in the detection of acute transplant rejection

Comparison of diagnostic value of coronary artery disease between ATP-stress and exercise-stress thallium myocardial SPECT images

International Nuclear Information System (INIS)

Suzuki, Shigeo

1994-01-01

A study was made between adenosine triphosphate disodium (ATP)-stress thallium myocardial scintigrams and exercise-stress scintigrams to compare their respective extents and degree of defects. The subjects of the study were 33 ischemic heart disease patients, who received ATP stress and treadmill exercise stress with a mean interval of 25 days. ATP was infused for 5 minutes with an infusion rate of 0.16 or 0.18 mg per kg of body weight per minute. Thallium was injected three minutes after infusion. The percent-defect index (percentage of the extent and degree of the defects for all 33 patients), was calculated with visual scoring using a five-zone myocardial division method and semi-quantitative four-grade representation method for both the ATP and exercise SPECT images. The extent of the defects in ATP- and exercise-stress images was 51.5% and 44.2%, and that in redistribution images was 36.4% and 33.9%, respectively. The degree of defects in ATP- and exercise-stress images was 35.8% and 32.3%, while that in redistribution images was 20.8% and 17.2%, respectively (p=NS in all cases). In conclusion, the image quality of thallium SPECT with ATP stress was equivalent that of exercise stress, indicating identical diagnostic values for coronary lesions. (author)

Usefulness of Thallium Scan for Differential Diagnosis of Breast Mass

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Bae, Sang Kyun; Yum, Ha Yong; Lee, Chung Han; Choi, Kyung Hyun [Kosin University College of Medicine, Pusan (Korea, Republic of)

1994-07-15

The purpose of this study is to evaluate thallium scanning as a potential test in differentiating malignant from benign lesions of breast. Thirty-one female patients underwent thallium scan of the breast. After intravenous injection of 74-111 MBq(2-3 mCi)of thallium-201, anterior and lateral images were obtained. We compared thallium scans with pathological results. Of 11 patients with breast cancers, 10 cases (90.9%) were detected using thallium scan. Thallium scan obtained in one patient who had breast cancer but received several cycles of chemotherapy did not show thallium uptake. The smallest detectable cancer was 1.5 cm in diameter. In contrast, there is no thallium accumulation in breasts of 17 of 20 patients with benign disease (85%), Three cases of 13 fibrocystic disease show thallium uptake in their breast. In conclusion, thallium scan is an effective test in differentiating benign from malignant lesion.

Usefulness of Thallium Scan for Differential Diagnosis of Breast Mass

International Nuclear Information System (INIS)

Bae, Sang Kyun; Yum, Ha Yong; Lee, Chung Han; Choi, Kyung Hyun

1994-01-01

The purpose of this study is to evaluate thallium scanning as a potential test in differentiating malignant from benign lesions of breast. Thirty-one female patients underwent thallium scan of the breast. After intravenous injection of 74-111 MBq(2-3 mCi)of thallium-201, anterior and lateral images were obtained. We compared thallium scans with pathological results. Of 11 patients with breast cancers, 10 cases (90.9%) were detected using thallium scan. Thallium scan obtained in one patient who had breast cancer but received several cycles of chemotherapy did not show thallium uptake. The smallest detectable cancer was 1.5 cm in diameter. In contrast, there is no thallium accumulation in breasts of 17 of 20 patients with benign disease (85%), Three cases of 13 fibrocystic disease show thallium uptake in their breast. In conclusion, thallium scan is an effective test in differentiating benign from malignant lesion.

Chest Pain with Normal Thallium-201 Myocardial Perfusion Image – Is It Really Normal?

Science.gov (United States)

Liu, Pang-Yen; Lin, Wen-Yu; Lin, Li-Fan; Lin, Chin-Sheng; Lin, Wei-Shiang; Cheng, Shu-Meng; Yang, Shih-Ping; Liou, Jun-Ting

2016-01-01

Background Thallium-201 myocardial perfusion image (MPI) is commonly used to detect coronary artery disease in patients with chest pain. Although a normal thallium-201 MPI result is generally considered to be a good prognosis and further coronary angiogram is not recommended, there are still a few patients who suffer from unexpected acute coronary events. The aim of this study was to investigate the clinical prognosis in patients with normal thallium-201 MPI. Methods From January 2006 to August 2012, a total 22,003 patients undergoing thallium-201 MPI in one tertiary center were screened. Of these, 8092 patients had normal results and were investigated retrospectively. During follow-up, 54 patients underwent coronary angiogram because of refractory typical angina pectoris or unexpected acute coronary events. These 54 patients were divided into 2 groups: group I consisted of 26 (48.1%) patients with angiography-proven significant coronary artery stenosis, and group II consisted of 28 (51.9%) patients without significant stenosis. Results Patients in group I had a higher prevalence of prior coronary stenting and electrocardiographic features of ST depression compared with patients in group II. The multivariate analysis demonstrated that both prior coronary stenting and ST depression were risk predictors of unexpected acute coronary events in the patients with normal thallium-201 MPI [odds ratio (OR), 5.93; 95% confidence interval (CI): 1.03-34.06, p = 0.05 and OR, 7.10; 95% CI: 1.28-39.51, p = 0.03,respectively]. Conclusions Although there is a low incidence of unexpected acute coronary events in patients with chest pain and normal thallium-201 MPI, physicians should be aware of the potentials risk in certain patients in this specific population. PMID:27274174

Evaluation of myocardial involvement in Duchenne's progressive muscular dystrophy with thallium-201 myocardial perfusion imaging

International Nuclear Information System (INIS)

Kawai, Naoki; Sotobata, Iwao; Okada, Mitsuhiro

1985-01-01

Myocardial involvement in progressive muscular dystrophy of the Duchenne type was evaluated in 19 patients using thallium-201 myocardial perfusion imaging. A qualitative analysis was performed from five projection images by three experienced physicians. Distinct perfusion defects were shown in 13 patients, especially in the LV posterolateral or posterior wall (11 patients). There was no significant relationship between the presence of perfusion defects and the skeletal muscle involvements or thoracic deformities assessed by transmission computed tomography. Extensive perfusion defects were shown in 2 patients who died of congestive heart failure 1 to 2 years after the scintigraphic study. Progression of the myocardial scintigraphic abnormalities were considered to be minimal in 7 of 9 patients who underwent two serial scintigraphic studies over 2 to 3 years. It was concluded that thallium myocardial perfusion imaging is a useful clinical technique to assess myocardial involvement in Duchenne's progressive muscular dystrophy. (author)

Pseudonormalization of transmitral flow pattern during exercise thallium-201 imaging in patients with coronary artery disease

International Nuclear Information System (INIS)

Shiota, Takahiro; Sakamoto, Tsuguya; Takenaka, Katsu; Amano, Keiko; Amano, Wataru; Igarashi, Tsutomu; Otake, Takeshi; Sugimoto, Tsuneaki

1993-01-01

This study was undertaken to assess the usefulness of Doppler parameters and transmitral blood velocity for detecting abnormalities of left ventricular diastolic function during low-level exercise thallium-201 imaging. The study population consisted of 16 thallium perfusion defect patients with coronary artery disease (mean 61±8 years) and 21 age-matched control subjects (mean 55±5 years) without any thallium perfusion defect. Of the 16 thallium perfusion defect patients, 12 were examined by coronary arteriography, of whom single vessel coronary artery disease was seen in 2 and multivessel coronary artery disease in 10. Patients with mitral regurgitant murmurs were excluded from the study. Peak mitral blood flow velocity was measured in early diastole (E) and during atrial systole (A) and the A/E ratio was calculated. The changes in blood pressure and heart rate after low-level exercise were not significantly different between control and thallium perfusion defect groups. The A/E ratio increased slightly in control subjects from 93±14% at baseline to 100±15% during low-level exercise (p<0.05), whereas in patients with thallium perfusion defect, it decreased significantly from 119±33% at baseline to 92±23% during low-level exercise (p<0.01). Thus pseudonormalization of the A/E ratio during low-level exercise may be valuable in the evaluation of patients with severe or multivessel coronary artery disease. (author)

Starting up stress thallium cardiac imaging services.

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Owens, R G; Neubecker, J S

1992-01-01

This paper presents an evaluation of alternative methods for a hospital to establish stress thallium cardiac imaging services at a group of physicians' office. Volume-cost-profit analysis, break-even analysis and capital budgeting techniques were used to determine the most feasible method from a financial perspective without sacrificing quality of services. The main focus of this evaluation centers upon three alternative methods of procuring an imaging camera: (1) purchasing a new camera, (2) purchasing used equipment, or (3) leasing a new camera. Budgeted income statements were constructed using relevant revenue and cost information for each alternative. The payback period, net present value and the internal rate of return for each method of procuring a camera was computed. In addition, the break-even point was also determined for each alternative. After the analysis was completed, it was concluded that the method of choice, without sacrificing quality of service delivery, was that of purchasing a used camera.

Visualization of atrial myocardium with thallium-201: case report

International Nuclear Information System (INIS)

Cowley, M.J.; Coghlan, H.C.; Logic, J.R.

1977-01-01

An adult patient evaluated for cyanotic congenital heart disease was found to have pulmonary atresia with intact ventricular septum, hypoplastic right ventricle, and right atrial enlargement. Thallium-201 myocardial imaging before surgical correction showed thallium activity in the right atrium. Following the establishment of a conduit from the right atrium to pulmonary artery, the right-atrial thallium uptake was even more prominent

The Effect and Side Effect of Dipyridamole in Myocardial SPECT

International Nuclear Information System (INIS)

Yang, Hyung In; Lee, Dong Soo; Yeo, Jeong Suk; Bae, Sang Kyun; Choi, Chang Woon; Chung, June Key; Lee, Myung Chul; Koh, Chang Soon

1993-01-01

Dipyridamole is an agent that may be used to noninvasively evaluate coronary artery disease. The effect of dipyridamole infusion its generally related to its induced peripheral vasodilatory effect. In normal person, heart rate is generally increased slightly while blood pressure decrease, but the achieved double product and related myocardial oxygen consumption have no significant change. The purpose of this study is to examine the effect and side effect of dipyridamole, and to compare different response to dipyridamole among the patients. We evaluated 847 patients who underwent dipyridamole stress myocardial SPECT. 93.6% of them had induced hypotension 0.9% showed no change of blood pressure, 5.5% had increased blood pressure 8.3% had no change of pulse rate more than 10% of basal pulse rate. Among diabetes, 16.9% was not change of pulse rate, 6.7% in non-diabetes. There was no significant correlation between age and rate pressure product rest(RPPr), in patients without perfusion defects on SPECT(y=7.1x+48.4r=0.13 p>0.01). As increasing age, RPPs/RPPr was declined(y=-11.6x+68.9 r=0.17 p<0.01), similar results were obtained in patients with perfusion defect. The size of perfusion defect on myocardial SPECT have no correlation between RPPr and RPPs/RPPr. The side effects of dipyridamole included chest pain and chest tightness, headache, abdominal pain, dizziness, nausea, and dyspnea. As increasing age, dipyridamole-induced cardiac work at rest was increased, cardiac response to dipyridamole was decreased.

Identification of viable myocardium in patients with chronic coronary artery disease and left ventricular dysfunction. Comparison of thallium scintigraphy with reinjection and PET imaging with 18F-fluorodeoxyglucose

International Nuclear Information System (INIS)

Bonow, R.O.; Dilsizian, V.; Cuocolo, A.; Bacharach, S.L.

1991-01-01

In patients with chronic coronary artery disease and left ventricular dysfunction, the distinction between ventricular dysfunction arising from myocardial fibrosis and ischemic, but viable, myocardium has important clinical implications. By positron emission tomography (PET), enhanced fluorine-18-labeled fluorodeoxyglucose (FDG) uptake in myocardial segments with impaired function and reduced blood flow is evidence of myocardial viability. Reinjection of thallium-201 at rest immediately after stress-redistribution imaging may also provide evidence of myocardial viability by demonstrating thallium uptake in regions with apparently irreversible defects. To compare these two methods, we studied 16 patients with chronic coronary artery disease and left ventricular dysfunction, all of whom had irreversible defects on standard exercise-redistribution thallium single-photon emission computed tomography (SPECT) imaging. Thallium was reinjected immediately after the redistribution study, and SPECT images were reacquired. The patients also underwent PET imaging with FDG and oxygen-15-labeled water. A total of 432 myocardial segments were analyzed from comparable transaxial tomograms, of which 166 (38%) had irreversible thallium defects on redistribution images before reinjection. FDG uptake was demonstrated in 121 (73%) of these irreversible defects. Irreversible defects were then subgrouped according to the degree of thallium activity, relative to peak activity in normal regions. Irreversible defects with only mild (60-85% of peak activity) or moderate (50-59% of peak) reduction in thallium activity were considered viable on the basis of FDG uptake in 91% and 84% of these segments, respectively. In contrast, in irreversible defects with severe reduction in thallium activity (less than 50% of peak), FDG uptake was present in 51% of segments

Quantitation of postexercise lung thallium-201 uptake during single photon emission computed tomography

International Nuclear Information System (INIS)

Kahn, J.K.; Carry, M.M.; McGhie, I.; Pippin, J.J.; Akers, M.S.; Corbett, J.R.

1989-01-01

To test the hypothesis that analysis of lung thallium uptake measured during single photon emission computed tomography (SPECT) yields supplementary clinical information as reported for planar imaging, quantitative analysis of lung thallium uptake following maximal exercise was performed in 40 clinically normal subjects (Group 1) and 15 angiographically normal subjects (Group 2). Lung thallium uptake was measured from anterior projection images using a ratio of heart-to-lung activities. Seventy subjects with coronary artery disease (CAD) (Group 3) determined by angiography (greater than or equal to 70% luminal stenosis) underwent thallium perfusion SPECT. Thirty-nine percent of these subjects had multivessel and 61% had single vessel CAD. Lung thallium uptake was elevated in 47 of 70 (67%) Group 3 subjects. Group 3 subjects with elevated lung thallium uptake did not differ from Group 3 subjects with normal lung thallium uptake with respect to extent or distribution of coronary artery disease, left ventricular function, or severity of myocardial ischemia as determined by exercise and redistribution thallium SPECT. Thus, the measurement of thallium lung uptake from anterior projection images obtained during SPECT frequently identifies patients with CAD, but it may not provide supplementary information regarding the extent of myocardial ischemia or ventricular dysfunction

Thallium-201 myocardial imaging in acute-myocardial infarction

International Nuclear Information System (INIS)

Wackers, F.J.Th.; Lie, K.I.; Sokole, E.B.; Wellens, H.J.J.; Samson, G.; Schoot, J.B. van der

1980-01-01

Thallium-201 scintigraphy has proven to be an early and highly sensitive technique to detect myocardial perfusion abnormalities in patients with acute myocardial infarction. During the early phase of acute myocardial infarction, patients may be hemodynamically and electrically unstable. Therefore, scintigraphy is performed preferably at the bed side in the Coronary Care Unit using a mobile gamma camera. Additionally, in order to shorten imaging time in these often critically ill patients, the authors recommend injecting no less than 2 mCi of 201 Tl. Using this dosage, the imaging time per view will be approximately five minutes. Routinely, three views are taken: the first view is a supine 45 0 left-anterior-oblique view, followed by a supine anterior view and finally a left-lateral view, the latter with the patient turned on the right side. (Auth.)

Coronary spasm induced by dipyridamole

International Nuclear Information System (INIS)

Wartski, M.; Caussin, C.; Lancelin, B.

2001-01-01

A 59 years old man was admitted at hospital for recurrent instable angina 1 month after coronary artery bypass surgery. Coronary artery disease started with a transmural antero-septo-apical myocardial infarction without thrombolysis and a percutaneous angioplasty with endo-prothesis on proximal left anterior descendant artery (LAD) is performed Because of recurrent rest angina and subacute stent thrombosis, a coronary artery bypass surgery (CABG) is performed with anastomosis of the left internal thoracic artery on LAD. The patient is admitted for recurrent rest angina one month after CABG. On ECG performed during chest pain, a ST-T segment elevation occurred on inferior leads. Coronary angiography showed no significant stenosis on endo-prothesis and no bypass graft dysfunction. Dipyridamole scintigraphy was realized. 2 minutes after the beginning of Dipyridamole infusion, a ST-T elevation occurred on inferior leads and two marked antero-septal and inferior defects were noticed on myocardial scintigraphy. Images at rest showed a clear improvement in the anterior wall and the inferior wall became normally perfused Patient was treated with anti-spastic drugs and a new coronarography with methyl-ergotamine test was performed inducing chest pain, ST-T elevation on inferior leads and tri-truncular coronary spasm. Patient's treatment was then modified with introduction of Nifedipine. The patient did not experienced new recurrent chest pain and remained totally asymptomatic few months later. (authors)

Quantification of reversible perfusion abnormality using exercise-stress thallium SPECT before and after coronary revascularization

International Nuclear Information System (INIS)

Nagao, Kazuhiko; Nakata, Tomoaki; Tsuchihashi, Kazufumi

1994-01-01

Reversible myocardial perfusion abnormality was quantified by bull's eye and unfolded surface mapping methods in exercise thallium SPECT before and after coronary revascularization in 47 patients with angina pectoris, including 34 patients with previous myocardial infarction (PMI) and 13 with effort angina (AP). There was no difference in the incidence or extent of myocardial ischemia between the 2 groups before revascularization. However, the ischemic scores were significantly smaller in PMI group preoperatively than the reductions of the ischemic scores after revascularization. The ischemic scores, preoperatively estimated reversible perfusion abnormality was 32%, 69% and 48% of the improvement of the ischemic score (extent score, severity score, and ischemic area, respectively). Using the 3 ischemic scores, the improvement of perfusion abnormality was well predicted in 70-89% of AP patients but 35-57% of PMI patients. Thus, quantitative analysis in stress thallium SPECT is useful for detecting myocardial ischemia and evaluating the effect of coronary revascularization. However, about a half of myocardial viability was underestimated in one third of PMI patients by the conventional exercise-stress thallium SPECT study. (author)

Serial assessment of myocardial thallium perfusion and fatty acid utilization in spontaneously hypertensive rats

International Nuclear Information System (INIS)

Sago, Masayoshi; Nishimura, Tsunehiko

1989-01-01

To evaluate the advantage of free fatty acid imaging on the detection of hypertrophied myocardium, we compared sequentially myocardial thallium and BMIPP (15-(p-iodophenyl)-3-(R,S)-methyl pentadecanoic acid) distribution in spontaneously hypertensive rat (SHR) using dual tracer autoradiography and in vivo pin-hole imaging. Autoradiography and pin-hole imaging showed uniform myocardial distribution of BMIPP and thallium within less than 27 weeks age SHR. In 40 weeks age SHR, thallium myocardial distribution showed uniform, however, BMIPP had focal decrease. Quantitative analysis of pin-hole images showed that myocardial BMIPP and thallium uptake ratio decreased according to the ages of SHR. Our data suggest that hypertension is associated with uniform myocardial perfusion and focal alternation in the substrate used for the performance of myocardial work. Based on the above autoradiographic and in vivo pin-hole imagings, I-123 BMIPP imaging may have a potential for early detection on hypertrophic myocardium compared to thallium perfusion in clinically hypertensive patients. (author)

Usefulness of 201Tl myocardial scintigraphy after dipyridamole infusion in patients with atherosclerotic vascular disease

International Nuclear Information System (INIS)

Toyama, Takuji; Nishimura, Tsunehiko; Uehara, Toshiisa

1992-01-01

To determine the utility for detecting ischemic heart disease (IHD), dipyridamole thallium myocardial images (DIP-Tl) have been performed in 103 patients with atherosclerotic vascular disease who can't exercise fully. Of the 103 patients, there were 36 patients with arteriosclerosis obliterans (ASO), 31 patients with aneurysm of the abdominal aorta (AAA), 24 patients with aneurysm of the thoracic aorta (TAA) and 12 patients with dissecting aortic aneurysm (DAA). Clinical evidence of IHD was found in 20 patients with ASO, 10 with AAA, 7 with TAA and 4 with DAA. Positive evidence of DIP-Tl was identified in 66% of 41 patients who had clinical evidence of IHD, and particularly in the patients with AAA (80%) and ASO (65%). On the other hand, in the patients without clinical evidence of IHD, positive evidence of DIP-Tl was identified in 19% of 62 patients and particularly in the patients with AAA (39%). In all patients, the percentage of the positive DIP-Tl ratio was 38%. And, when the 38% patients of the positive DIP-Tl were added to the patients of the negative DIP-Tl who had clinical evidence of IHD, almost half patients (51%) were considered to be complicated with IHD. This study suggests that the atherosclerotic vascular disease is highly complicated with IHD and DIP-Tl is useful to detect IHD. (author)

IRIS Toxicological Review of Thallium and Compounds ...

Science.gov (United States)

Thallium compounds are used in the semiconductor industry, the manufacture of optic lenses and low-melting glass, low-temperature thermometers, alloys, electronic devices, mercury lamps, fireworks, and imitation germs, and clinically as an imaging agent in the diagnosis of certain tumors. EPA's assessment of noncancer health effects and carcinogenic potential of thallium compounds was last prepared and added to the IRIS database between 1988 and 1990. The IRIS program is preparing an assessment that will incorporate current health effects information available for thallium and compounds, and current risk assessment methods. The IRIS assessment for thallium compounds will consist of a Toxicological Review and IRIS Summary. The Toxicological Review is a critical review of the physiochemical and toxicokinetic properties of a chemical, and its toxicity in humans and experimental systems. The assessment will present reference values for the noncancer effects of thallium compounds (RfD and Rfc), and a cancer assessment. The Toxicological Review and IRIS Summary have been subject to Agency review, Interagency review, and external scientific peer review. The final product will reflect the Agency opinion on the overall toxicity of thallium and compounds. EPA is undertaking an Integrated Risk Information System (IRIS) health assessment for thallium and compounds. IRIS is an EPA database containing Agency scientific positions on potential adverse human health effec

Technetium-99m sestamibi myocardial tomography based on dipyridamole echocardiography testing in hypertensive patients with chest pain

Energy Technology Data Exchange (ETDEWEB)

Schillaci, O. [Section of Nuclear Medicine, Department of Experimental Medicine and Pathology, University ``La Sapienza``, Rome (Italy); Moroni, C. [Department of Internal Medicine, University ``La Sapienza``, Rome (Italy); Scopinaro, F. [Section of Nuclear Medicine, Department of Experimental Medicine and Pathology, University ``La Sapienza``, Rome (Italy); Tavolaro, R. [Section of Nuclear Medicine, Department of Experimental Medicine and Pathology, University ``La Sapienza``, Rome (Italy); Danieli, R. [Section of Nuclear Medicine, Department of Experimental Medicine and Pathology, University ``La Sapienza``, Rome (Italy); Bossini, A. [Department of Internal Medicine, University ``La Sapienza``, Rome (Italy); Cassone, R. [Department of Internal Medicine, University ``La Sapienza``, Rome (Italy); Colella, A.C. [Section of Nuclear Medicine, Department of Experimental Medicine and Pathology, University ``La Sapienza``, Rome (Italy)

1997-07-01

The aim of this study was to evaluate the diagnostic capability of technetium-99m sestamibi tomography based on dipyridamole echocardiography testing in hypertensives with chest pain, and to compare the scintigraphic results with those of coronary angiography, exercise electrocardiography and dipyridamole echocardiography. Forty subjects with mild to moderate hypertension, chest pain and no previous myocardial infarction were submitted to {sup 99m}Tc-sestamibi tomography (at rest and after high-dose dipyridamole echocardiography) and to exercise electrocardiography testing. At coronary angiography 22 patients (group A) had significant epicardial coronary artery disease ({>=}70% stenosis of at least one major vessel) and 18 normal main coronary vessels (group B). Dipyridamole {sup 99m}Tc-sestamibi imaging was positive in 21/22 patients of group A and in 5/18 of group B. Dipyridamole echocardiography was positive in 18/22 patients of group A and in 5/18 of group B. Exercise electrocardiography was positive in 15/22 patients of group A and in 11/18 of group B. Four out of five subjects in group B with positive results in all the tests showed a slow run-off of angiographic contrast medium, probably due to small-vessel disease. Significant epicardial coronary artery disease in hypertensives with chest pain is unlikely when dipyridamole {sup 99m}Tc-sestamibi tomography is negative. When scintigraphy is positive, either epicardial coronary artery disease or a small-vessel disease condition is possible. The association of scintigraphy with dipyridamole echocardiography testing allows the assessment of contractile function and myocardial perfusion by a single pharmacological stress. (orig./AJ). With 3 figs., 2 tabs.

Left ventricular dilatation and pulmonary thallium uptake after single-photon emission computer tomography using thallium-201 during adenosine-induced coronary hyperemia

International Nuclear Information System (INIS)

Iskandrian, A.S.; Heo, J.; Nguyen, T.; Lyons, E.; Paugh, E.

1990-01-01

This study examined the implications of left ventricular (LV) dilatation and increased pulmonary thallium uptake during adenosine-induced coronary hyperemia. The lung-to-heart thallium ratio in the initial images was significantly higher in patients with coronary artery disease (CAD) than normal subjects; 0.48 +/- 0.16 in 3-vessel disease (n = 16), 0.43 +/- 0.10 in 2-vessel disease (n = 20), 0.43 +/- 0.08 in 1-vessel disease (n = 16) and 0.36 +/- 0.05 in normal subjects (n = 7) (p less than 0.001, 0.09 and 0.06, respectively). There was a significant correlation between the severity and the extent of the perfusion abnormality (determined from the polar maps) and the lung-to-heart thallium ratio (r = 0.51 and 0.52, respectively, p less than 0.0002). There was also a significant correlation between lung thallium washout and lung-to-heart thallium ratio (r = 0.42, p = 0.0009) and peak heart rate (r = -0.49, p less than 0.0001). The LV dilatation was mostly due to an increase in cavity dimension (30% increase) and to a lesser extent (6% increase) due to increase in LV size. (The cavity dimensions were measured from the short-axis slices at the midventricular level in the initial and delayed images). The dilation was seen in patients with CAD but not in the normal subjects. These changes correlated with the extent and severity of the thallium perfusion abnormality. Thus, adenosine-induced coronary hyperemia may cause LV dilation and increased lung thallium uptake on the basis of subendocardial ischemia

Noninvasive detection of coronary artery disease by dipyridamole-loading 201thallium myocardial scintigraphy

International Nuclear Information System (INIS)

Hamashige, Naohisa; Doi, Yoshinori; Yonezawa, Yoshihiro; Odawara, Hiroaki; Ozawa, Toshio; Akagi, Naoki; Yoshida, Shoji; Maeda, Tomoho

1986-01-01

Fifty patients with suspected coronary artery disease (CAD) were given i.v. infusion of 0.568 mg/kg of dipyridamole (DP) for 4 min in the supine position, and were loaded by stepping. Myocardial DP scanning (DP scintigraphy) was then performed with i.v. injection of 3 mCi of Tl-201 chloride. Findings were compared with those of coronary angiography and treadmill ECG. DP scintigraphy had higher sensitivity (90 %) and specificity (95 %) than treadmill ECG (76 % and 67 %) in diagnosing a ≥ 75 % coronary stenosis. Twenty nine patients had significant CAD: Reversible defects were associated with chest pain in 79 %, and with ST depression in 76 %. Not only relative differences in blood flow between the normal and diseased sites but also ischemia was suggested to be responsible for these defects. Increased rate pressure product by DP scintigraphy was slight (34 %) compared with that by treadmill ECG (105 %), suggesting a strong involvement of redistribution of coronary blood flow in the occurrence of ischemia. Increased myocardial oxygen consumption due to stepping was considered as the cause of ischemia as well, because the incidence of chest pain and ST depression was higher than previously reported. Chest pain and ST depression improved by i.v. injection of aminophylline. (Namekawa, K.)

The cardiomyopathy in Friedreich's ataxia: isotopic ventriculography and myocardial imaging with thallium-201

International Nuclear Information System (INIS)

Therriault, L.; Lamoureux, G.; Cote, M.; Plourde, G.; Lemieux, B.

1984-01-01

Myocardial scanning after the intravenous administration of Thallium 201 was used to evaluate regional myocardial perfusion in 14 patients with Friedreich's ataxia. Isotopic ventriculography was also used to assess left ventricular contractility. Myocardial images in patients with Friedreich's ataxia were found to be precociously abnormal irrespective of the degree of neurological impairment or of the severity of myocardial hypertrophy

Reduction of indium-111 platelet deposition on Dacron vascular grafts in humans by aspirin plus dipyridamole

International Nuclear Information System (INIS)

Stratton, J.R.; Ritchie, J.L.

1986-01-01

Aspirin plus dipyridamole reduces platelet accumulation on short-term Dacron vascular grafts in man. To determine whether drug inhibition of platelet deposition is sustained on older grafts, we studied 18 men aged 41 to 87 years who had Dacron aortic bifurcation grafts in place a mean of 43.4 months (range 9.8 to 121.0) before and during short-term therapy with aspirin (325 mg tid) plus dipyridamole (75 mg tid). During both the baseline and drug studies, indium-111 ( 111 In) platelet deposition was quantitated by two techniques, standard planar imaging performed at 24, 48, and 72 hr after injection of platelets and single photon emission computed tomographic imaging performed at 24 and 72 hr after injection. All analyses were performed in a blinded fashion. On both the planar and tomographic images, platelet accumulation on the graft was quantitated by a graft/blood ratio that compared activity in the graft to simultaneously collected whole blood 111 In platelet activity. Aspirin plus dipyridamole reduced the tomographic graft/blood ratio at 24 hr (20.6 +/- 3.5 vs 17.3 +/- 2.5) (+/-SEM) and at 72 hr (29.0 +/- 4.8 vs 25.0 +/- 4.1) after injection of platelets (p = .02). Dacron vascular grafts. Similarly, the planar graft/blood ratio was reduced at 24 hr (2.7 +/- 0.5 vs 2.4 +/- 0.5), 48 hr (3.7 +/- 0.9 vs 3.1 +/- 0.7), and 72 hr (4.0 +/- 0.9 vs 3.6 +/- 0.8) (p = .04). We conclude that aspirin (325 mg tid) plus dipyridamole (75 mg tid) reduces platelet accumulation on long-term Dacron vascular grafts

Exercise thallium-201 scintigraphy in evaluating aortocoronary bypass surgery

International Nuclear Information System (INIS)

Iskandrian, A.S.; Haaz, W.; Segal, B.L.; Kane, S.A.

1981-01-01

Thirty patients with recurrent symptoms after aortocoronary bypass graft surgery underwent angiography as well as exercise thallium 201 imaging. Exercise imaging has been shown to be highly specific (100 percent in our study) in evaluating patients after bypass surgery. Patients with complete revascularization have normal thallium 201 images. Similarly, exercise-induced defects are seen only in the presence of incomplete revascularization. There are patients, however, with incomplete revascularization with normal exercise images, but these generally limited to the right coronary artery or the diagonal vessels or their grafts

Noninvasive external cardiac pacing for thallium-201 scintigraphy

International Nuclear Information System (INIS)

Feldman, M.D.; Warren, S.E.; Gervino, E.V.

1988-01-01

Improvements in noninvasive external cardiac pacing have led to a technique with reliable electrical capture and tolerable patient discomfort. To assess the use of this modality of pacing in combination with thallium scintigraphy as a noninvasive pacing stress test, we applied simultaneous noninvasive cardiac pacing, hemodynamic monitoring, and thallium-201 scintigraphy in 14 patients undergoing cardiac catheterization for chest pain syndromes. Two patients had normal coronary arteries, while the remaining 12 had significant coronary artery disease. Thallium scintigraphic responses to pacing were compared to routine exercise thallium stress testing in nine of these 14 patients. All patients were noninvasively paced to more than 85% of the age-predicted maximum heart rate. Twelve patients demonstrated reversible thallium defects, which corresponded in 11 cases to significant lesions seen on coronary angiography. Of nine patients who underwent both pacing and exercise thallium stress tests, comparable maximal rate-pressure products were achieved. Moreover, thallium imaging at peak pacing and during delayed views did not differ significantly from exercise thallium scintigraphy. A limiting factor associated with the technique was local patient discomfort, which occurred to some degree in all patients. We conclude that noninvasive external cardiac pacing together with thallium scintigraphy is capable of detecting significant coronary artery disease and may be comparable to routine exercise thallium stress testing. This new modality of stress testing could be useful in patients unable to undergo the exercise required for standard exercise tolerance testing, particularly if improvements in the technology can be found to reduce further the local discomfort

Dipyridamole dilates large cerebral arteries concomitant to headache induction in healthy subjects

DEFF Research Database (Denmark)

Kruuse, Christina; Jacobsen, T B; Lassen, L H

2000-01-01

Dipyridamole is used for secondary prophylaxis in ischemic stroke and as a vasodilator agent in myocardial scintigraphy. An important side effect to administering dipyridamole is headache. The aim of the current study was to investigate the effects of dipyridamole on cerebral blood flow, large ar...... causes a modest pCO2 independent dilatation of the MCA, which is time-linked to the onset, but not to the cessation, of headache....... a mean 5.6% +/- 6.7 (P = 0.005) relative increase of the arterial diameter. After dipyridamole the median peak headache score was 2 (range 0 to 7) compared with 0 (range 0 to 3) after placebo (P = 0.02). Dilatation of the middle cerebral artery outlasted the headache response. In conclusion, dipyridamole...

Evaluation of Coronary Artery Disease with Gated Blood Pool Scan Using Dipyridamole

International Nuclear Information System (INIS)

Kim, Gwang Weon; Choi, Chung Il; Chung, Byung Cheon; Lee, Jae Tae; Lee, Kyu Bo; Chae, Shung Chull; Jun, Jae Eun; Park, Wee Hyun; Park, Hee Myung

1991-01-01

Thirty-one patients with coronary artery disease and twenty-six normal subjects underwent 99m Tc-GBPS before and after coronary vasodilatation was induced by dipyridamole 0.54 mg/kg given IV over 4 min. LVKF, EF and regional wall motion by phase analysis were measured during rest and dipyridamole infusion. The results were as follows: 1) Mean LVEF of normal subjects was significantly higher than that of MI group (p=0.001), but similar to that of angina group during rest. Among Ml group, mean LVEF of anterior MI group was significantly lower than that of inferior MI group during rest (p=0,024). 2) The normal subjects had a significant increase in mean LVEF during dipyridamole infusion (+ 12 ± 3.8), while the CAD group had no increase (+ 2=5.0) (p<0.001). If an increase of LVEF during stress is less than 5%, it suggests an abnormality. The sensitivity and specificity of LUEF changes after dipyridamole infusion were 81%, 96%, respectively. 3) With phase analysis, LV mean phase angle of normal subjects and CAD patients was 143 + 20, 5, 132 ± 20.6 respectively, during rest (p=0.049). But an increase of LV mean phase angle during dipyridamole infusion in these two groups was not significantly different. Dipyridamole infusion did not affect standard deviation and FWHM of phase angle. 4) Regional wall motion was abnormal in 5 patients (16%) during dipyridamole infusion. 5) Side effects with dipyridamole infusion include; headache, angina pain, chest discomfort, nausea, weakness sense. In conclusion, dipyridamole GBPS might be useful in detection and follow up of CAD.

Exercise thallium testing in ventricular preexcitation

Energy Technology Data Exchange (ETDEWEB)

Archer, S.; Gornick, C.; Grund, F.; Shafer, R.; Weir, E.K.

1987-05-01

Ventricular preexcitation, as seen in Wolff-Parkinson-White syndrome, results in a high frequency of positive exercise electrocardiographic responses. Why this occurs is unknown but is not believed to reflect myocardial ischemia. Exercise thallium testing is often used for noninvasive assessment of coronary artery disease in patients with conditions known to result in false-positive electrocardiographic responses. To assess the effects of ventricular preexcitation on exercise thallium testing, 8 men (aged 42 +/- 4 years) with this finding were studied. No subject had signs or symptoms of coronary artery disease. Subjects exercised on a bicycle ergometer to a double product of 26,000 +/- 2,000 (+/- standard error of mean). All but one of the subjects had at least 1 mm of ST-segment depression. Tests were terminated because of fatigue or dyspnea and no patient had chest pain. Thallium test results were abnormal in 5 patients, 2 of whom had stress defects as well as abnormally delayed thallium washout. One of these subjects had normal coronary arteries on angiography with a negative ergonovine challenge, and both had normal exercise radionuclide ventriculographic studies. Delayed thallium washout was noted in 3 of the subjects with ventricular preexcitation and normal stress images. This study suggests that exercise thallium testing is frequently abnormal in subjects with ventricular preexcitation. Ventricular preexcitation may cause dyssynergy of ventricular activation, which could alter myocardial thallium handling, much as occurs with left bundle branch block. Exercise radionuclide ventriculography may be a better test for noninvasive assessment of coronary artery disease in patients with ventricular preexcitation.

Exercise thallium testing in ventricular preexcitation

International Nuclear Information System (INIS)

Archer, S.; Gornick, C.; Grund, F.; Shafer, R.; Weir, E.K.

1987-01-01

Ventricular preexcitation, as seen in Wolff-Parkinson-White syndrome, results in a high frequency of positive exercise electrocardiographic responses. Why this occurs is unknown but is not believed to reflect myocardial ischemia. Exercise thallium testing is often used for noninvasive assessment of coronary artery disease in patients with conditions known to result in false-positive electrocardiographic responses. To assess the effects of ventricular preexcitation on exercise thallium testing, 8 men (aged 42 +/- 4 years) with this finding were studied. No subject had signs or symptoms of coronary artery disease. Subjects exercised on a bicycle ergometer to a double product of 26,000 +/- 2,000 (+/- standard error of mean). All but one of the subjects had at least 1 mm of ST-segment depression. Tests were terminated because of fatigue or dyspnea and no patient had chest pain. Thallium test results were abnormal in 5 patients, 2 of whom had stress defects as well as abnormally delayed thallium washout. One of these subjects had normal coronary arteries on angiography with a negative ergonovine challenge, and both had normal exercise radionuclide ventriculographic studies. Delayed thallium washout was noted in 3 of the subjects with ventricular preexcitation and normal stress images. This study suggests that exercise thallium testing is frequently abnormal in subjects with ventricular preexcitation. Ventricular preexcitation may cause dyssynergy of ventricular activation, which could alter myocardial thallium handling, much as occurs with left bundle branch block. Exercise radionuclide ventriculography may be a better test for noninvasive assessment of coronary artery disease in patients with ventricular preexcitation

Evaluation of myocardial fatty acid metabolism in the area of fill-in after thallium reinjection in patients with prior myocardial infarction

International Nuclear Information System (INIS)

Matsunari, Ichiro; Fujino, Susumu; Nishikawa, Takahiro; Ichiyanagi, Kenji; Taki, Junichi; Nakajima, Kenichi; Tonami, Norihisa; Hisada, Kinichi.

1995-01-01

Myocardial fatty acid utilization in the area with thallium fill-in after reinjection was assessed using 123 I-labeled 15-(p-iodophenyl) 3R, S-methylpentadecanoic acid (BMIPP). We studied 22 patients with prior myocardial infarction that revealed persistent defects on standard exercise-redistribution thallium imaging. In each patient, exercise-redistribution-reinjection thallium imaging was performed. Within two weeks of the thallium study, resting BMIPP imaging was performed 20 min after injection of BMIPP (148 MBq). Following qualitative analysis of the obtained thallium and BMIPP images, quantitative analysis was performed on the basis of relative regional uptake. Of 199 myocardial segments that showed persistent defects on exercise-redistribution images, 73 segments showed apparent fill-in on the reinjection images (fill-in positive), and the remaining 126 segments did not (fill-in negative). When BMIPP images were compared with the corresponding thallium reinjection images, reduced BMIPP uptake compared with thallium was frequently observed in the area of fill-in positive segments (65 of 73 segments, 89%). Quantitative analysis also showed decrease in BMIPP activity compared to thallium activity in the area of fill-in (49.7±16.1 vs. 65.8±16.0%, p<0.001). In contrast, only 24 of the 126 fill-in negative segments (19%) showed lower BMIPP uptake than thallium. These results suggest that impaired fatty acid utilization in the area of thallium new fill-in after reinjection already exists at resting condition. Thus, BMIPP imaging combined with exercise-redistribution-reinjection thallium imaging provides insights to understanding fatty acid utilization in ischemic but viable myocardium identified by thallium reinjection in patients with prior myocardial infarction. (author)

Swimming clusters in thallium-rich liquid caesium-thallium alloys

NARCIS (Netherlands)

van der Aart, SA; van der Lugt, W; Badyal, YS; Verkerk, P

The purpose of the work presented here is to obtain structural information on thallium-rich caesium-thallium alloys by means of neutron diffraction. The alloys exhibit a long-range (>1 nm) superstructure. This range increases with the thallium content. The results are interpreted with the help of a

First results in postoperative functional imaging of parathyroid tissue with thallium-201-chloride

International Nuclear Information System (INIS)

Schwartz, K.D.; Michael, R.; Karsten, U.; Pietsch, P.; Brietzke, W.; Tredt, H.J.; Dabels, J.; Labes, K.

1984-01-01

On account of diagnostic uncertainties Se-75-methionine failed to become accepted clinically for detecting parathyroid adenomas. But recent reports in the literature suggested satisfactory results to be achieved with a double-nuclide technique using Thallium-201-chloride for parathyroid imaging. Data of 6 patients were evaluated to shed light on the usefulness of radio-Thallium for postoperative functional imaging of heterotopic parathyroid tissue. Analogous studies using Se-75-methionine had previously been carried out by other authors. Early results suggest the method to have clinical relavance. Four patients with cubital vein parathormone levels that were higher on the grafted versus the ungrafted side were found to have significantly elevated Tl-201 uptake in the region of the surgical scar on the forearm. Two patients with no or little difference in PTH concentrations between the 2 sides showed no or at best some slight activity increase. The place of this method as an alternative to differential cubital vein parathormone assaying still remains to be established. In view of the poor cubital veins of dialysis patients it appears to hold promises for assessing the function of parathyroid grafts in the forearm. (Author)

Occult primary tumors of the head and neck: accuracy of thallium 201 single-photon emission computed tomography and computed tomography and/or magnetic resonance imaging

NARCIS (Netherlands)

van Veen, S. A.; Balm, A. J.; Valdés Olmos, R. A.; Hoefnagel, C. A.; Hilgers, F. J.; Tan, I. B.; Pameijer, F. A.

2001-01-01

To determine the accuracy of thallium 201 single-photon emission computed tomography (thallium SPECT) and computed tomography and/or magnetic resonance imaging (CT/MRI) in the detection of occult primary tumors of the head and neck. Study of diagnostic tests. National Cancer Institute, Amsterdam,

Relations among impaired coronary flow reserve, left ventricular hypertrophy and thallium perfusion defects in hypertensive patients without obstructive coronary artery disease

International Nuclear Information System (INIS)

Houghton, J.L.; Frank, M.J.; Carr, A.A.; von Dohlen, T.W.; Prisant, L.M.

1990-01-01

Invasive Doppler catheter-derived coronary flow reserve, echocardiographic measurements of left ventricular hypertrophy and intravenous dipyridamole-limited stress thallium-201 scintigraphy were compared in 48 patients (40 were hypertensive or diabetic) with clinical ischemic heart disease and no or minor coronary artery disease. Abnormal vasodilator reserve (ratio less than 3:1) occurred in 50% of the study group and markedly abnormal reserve (less than or equal to 2:1) occurred in 27%. Coronary vasodilator reserve was significantly lower (2.2 +/- 0.8 versus 3.5 +/- 1.3, p = 0.003) and indexed left ventricular mass significantly higher (152.6 +/- 42.2 versus 113.6 +/- 24.0 g, p = 0.0007) in patients with a positive (n = 11) versus a negative (n = 32) thallium perfusion scan. Coronary flow reserve was linearly related in coronary basal flow velocity as follows: y = -0.17x + 4.59; r = -0.57; p = 0.00002. The decrement in flow reserve was not linearly related to the degree of left ventricular hypertrophy. Abnormal vasodilator reserve subsets found in hypertensive patients were defined on the basis of basal flow velocity, indexed left ventricular mass and clinical factors. In this series, diabetes did not cause a detectable additional decrement in flow reserve above that found with hypertension alone. These findings demonstrate that thallium perfusion defects are associated with depressed coronary vasodilator reserve in hypertensive patients without obstructive coronary artery disease. Left ventricular hypertrophy by indexed mass criteria is predictive of which hypertensive patients are likely to have thallium defects

Myocardial imaging with thallium-201: an experimental model for analysis of the true myocardial and background image components

International Nuclear Information System (INIS)

Narahara, K.A.; Hamilton, G.W.; Williams, D.L.; Gould, K.L.

1977-01-01

The true myocardial and background components of a resting thallium-201 myocardial image were determined in an experimental dog model. True background was determined by imaging after the heart had been removed and replaced with a water-filled balloon of equal size and shape. In all studies, the background estimated from the region surrounding the heart exceeded true background activity. Furthermore, the relationship between true myocardial background and that estimated from the pericardiac region was inconsistent. Background estimates based on the activity surrounding the heart were not accurate predictors of true background activity

Tardily accelerated neurologic deterioration in two-step thallium intoxication.

Science.gov (United States)

Kuroda, Hiroshi; Mukai, Yoshiyuki; Nishiyama, Shuhei; Takeshita, Takayuki; Tateyama, Maki; Takeda, Atsushi; Aoki, Masashi

2016-12-01

Thallium intoxication was reported in cases with accidental ingestion, suicide attempt, and criminal adulteration. Reported cases were mostly one-time ingestion, therefore, the clinical course of divisional ingestion has not been fully known. Here, we report a case with two-step thallium intoxication manifesting as tardily accelerated neurologic deterioration. A 16-year-old adolescent was cryptically poisoned with thallium sulfate twice at an interval of 52days. After the first ingestion, neurologic symptoms including visual loss, myalgia, and weakness in legs developed about 40days after the development of acute gastrointestinal symptoms and alopecia. After the second ingestion, neurologic symptoms deteriorated rapidly and severely without gastrointestinal or cutaneous symptoms. Brain magnetic resonance imaging exhibited bilateral optic nerve atrophy. Nerve conduction studies revealed severe peripheral neuropathies in legs. Thallium intoxication was confirmed by an increase in urine thallium egestion. Most of the neurologic manifestations ameliorated in two years, but the visual loss persisted. The source of thallium ingestion was unraveled afterward because a murder suspect in another homicidal assault confessed the forepast adulteration. This discriminating clinical course may be attributable to the cumulative neurotoxicity due to the longer washout-time of thallium in the nervous system than other organs. It is noteworthy that the divisional thallium intoxication may manifest as progressive optic and peripheral neuropathy without gastrointestinal or cutaneous symptoms. Copyright © 2016 Elsevier Ltd. All rights reserved.

Risk stratification of patients with hypertension using exercise thallium-201 scintigraphy

International Nuclear Information System (INIS)

Iskandrian, A.S.; Hakki, A.H.; Kane, S.

1985-01-01

Hypertension (HT) is an important risk factor in coronary heart disease (CHD) and cardiac morbidity and mortality. This study examined the value of clinical, ECG, exercise (EX) and thallium-201 imaging descriptors that identify patients (pts) with HT at high risk. The 337 pts in the study underwent EX thallium-201 testing for evaluation of chest pain due to suspected or proven CHD. The mean age was 55 years, of whom 79% were still on active anti-HT therapy at the time of the study. The EX thallium scintigrams were evaluated qualitatively and quantitively using circumferential profile analysis. The scans were abnormal in 162 pts (48%) and reversible perfusion defects were present in 106 of the 162 pts (65%). At a folllowup fo up to 74 months, (15 +- 9 mean +- SD), 11 pts had hard cardiac events: 2 died of cardiac causes and 9 had non-fatal acute myocardial infractions. There were no significant differences between those with and without events in age, EX heart rate and double product, EX duration, blood pressure and EX ECG changes. Univariate and multivariate survival analysis (Cox regression model) of important clinical, ECG, EX and thallium variables, identified the presence of abnormal EX images as the only predictor of outcome. (X/sup 2/ = 5.4, p< 0.02). No other variable provided additional prognostic information. Actuarial life table analysis showed that pts with abnormal images had significantly more events than those with normal images (p = 0.008, Mantel-Cox). Thus, EX thallium imaging is useful in risk stratification in pts with HT. The presence of abnormal images identify a subgroup at high risk for future events

Methods of thallium-201 preparation from proton irradiated thallium targets

International Nuclear Information System (INIS)

Kozlova, M.D.; Sevast'yanova, A.S.; Malinin, A.B.; Kurenkov, N.V.

1989-01-01

Two methods of thallium-201 preparation from Tl-targets irradiated by protons: oxidation-extraction (1) and extraction (2) - are developed. At first radioactive lead is separated from the target material - thallium macroquantities during ∼32 hours, then thallium-201 was separated from residual activity of lead radioisotopes and transformed it into the necessary chemical formula. The 1st and 2nd methods differ from each other by the 1st stage of target retreatment; only extraction was used to separate radioactive lead in the 2nd method. The target was solved in H 2 SO 4 . The 1st method permits to separate thallium-201 with chemical yield not less than 90 %, the 2nd one - higher than 95 %. Volumetric activity of thallium-201 prepared is more than 55 MBq/ml. 5 refs

Mechanisms of thallium-201 accumulation to thyroid gland

International Nuclear Information System (INIS)

Kishida, Toshihiro

1987-01-01

In this study 91 patients with goiter were scintigraphed for the duration of 84 minutes after intravenous administration of thallium-201 by digital γ camera lined to computer data system. Regions of interest (ROIs) were assigned for thyroid tumor, normal thyroid and back ground, and time-activity curves (TACs) were generated from these ROIs. Na + , K + -ATPase activity of microsome fraction from thyroid tumor and the normal thyroid glands was determined. The first 15 minutes accumulation of each ROI was determined as the early accumulation of thallium-201 for tumor and the normal thyroid glands. Papillary and follicular carcinomas, showing the high accumulation of thallium-201, had high activity of Na + , K + -ATPase. Microfollicular adenomas had high activity of Na + , K + -ATPase and demonstrated intense accumulation of thallium-201. However, colloid adenoma had a similar level of Na + , K + -ATPase activity to that of the normal thyroid glands and did not demonstrate radionuclide accumulation. Consequently, radionuclide accumulation in thallium-201 thyroid scintigraphy was closely correlated to Na + , K + -ATPase activity of thyroid tumor. Thyroid blood flow was measured by hydrogen gas clearance method. Thyroid blood flow of papillary carcinoma was smaller, as compared with normal thyroid blood flow. TAC of papillary carcinoma showed flattening. Thallium-201 accumulation in early image was also found to correspond to thyroid blood flow. From this study we can conclude that mechanisms of thallium-201 accumulation in a thyroid tumor depends on Na + , K + -ATPase activity and thyroid blood flow. Washout of TAC in thallium-201 scintigraphy appears dependent on blood flow of a thyroid nodule. (author)

Reverse redistribution on planar thallium scintigraphy: relationship to resting thallium uptake and long-term outcome

International Nuclear Information System (INIS)

Dey, H.M.; Soufer, R.

1995-01-01

Reverse redistribution (RR) of thallium-201 has been associated with both acute and healed myocardial infarction, and with recent thrombolysis. The physiologic basis for RR in coronary artery disease (CAD) is unclear but may be related to an admixture of viable and scarred myocardium within the RR segment. We performed thallium reinjection imaging at rest to better characterize RR defects in patients with chronic CAD. We found enhanced uptake of 201 Tl in 52% of RR segments after reinjection, consistent with significant regional viability that was not evident on redistribution images. We then used a logistic multiple regression analysis to determine whether RR alone or in combination with other scintigraphic findings could predict patient outcome. The results showed that severe RR was an independent predictor of patient outcome. We conclude that RR may have prognostic significance in chronic CAD. (orig.)

Utility of thallium-201 and iodine-123 metaiodobenzylguanidine in the scintigraphic detection of neuroendocrine neoplasia

International Nuclear Information System (INIS)

Montravers, F.; Coutris, G.; Sarda, L.; Mensch, B.; Talbot, J.N.

1993-01-01

In order to determine whether the association of the two markers is able to improve the detection of neuroendocrine lesions, 137 sctinigraphic examinations using MIBG and thallium were performed in 101 patients referred for suspicion or follow-up of neuroendocrine tumours. Thallium chloride was first injected (1 MBq/kg), images being acquired about 20 min after injection; 123 I-MIBG (4 MBq/kg) was then injected and images acquired 5 and 24 h later. In patients with phaeochromocytoma or neuroblastoma, thallium scintigraphy appeared of little help since no tumoural site was discovered by thallium accumulation alone. In contrast, thallium examination seemed of interest in the detection of paraganglioma and MTC, the association of the two radiopharmaceuticals increasing the number of detected sites. (orig./MTG)

201Thallium SPECT, accuracy in astrocytoma diagnosis and treatment evaluation

International Nuclear Information System (INIS)

Kaellen, K.

1999-10-01

The aims of the studies included in this thesis were: - to investigate the reliability of 201 Thallium single photon emission computed tomography. Tl SPECT for preoperative diagnosis and histological staging of malignant astrocytomas in comparison with CT; - to develop a method for quantification of cerebral thallium uptake, and to evaluate the quantitative measurement in comparison with CT, for astrocytoma treatment follow-up purposes; - to compare quantitative Tl SPECT and proton magnetic resonance spectroscopy (H-MRS) with conventional MR imaging for astrocytoma monitoring, and to evaluate associations between change of morphological tumour characteristics during treatment and changes of cerebral thallium uptake and metabolic ratios. Results and conclusions: - High TI-index, calculated as a ratio comparing tumour uptake to uptake in the contralateral hemisphere, is an indicator of highly malignant astrocytoma. Differentiation between the high-grade astrocytomas, the low-grade astrocytomas, and infectious lesions is only partial, with an overlap of Tl-indexes between these groups. High-grade astrocytomas that do not show contrast enhancement on CT, and astrocytomas with central necrosis and moderate ring-enhancement, tend to be underestimated when evaluated by Tl-index calculation. Tl SPECT is not a reliable method for non-invasive tumour staging among the group of highly malignant astrocytomas. - Quantification of cerebral TI-uptake, defining the volume of viable tumour tissue, is a new method for astrocytoma chemotherapy monitoring. Results suggest that the method provides prognostic information, and information of treatment efficacy, at an earlier stage than CT. - We did not find a higher accuracy of quantitative Tl SPECT than of MR for monitoring purposes and our results indicated that treatment induced MR changes were interrelated with TI-uptake variations. - Multi-voxel H-MRS was difficult to apply for astrocytoma treatment monitoring, due to the anatomical

The use of thallium-201 scintigraphy in the assessment and management of bone and soft tissue tumours

International Nuclear Information System (INIS)

Jong, I.; Schlicht, S.M.; Smith, P.; J Slavin; Powell, G.; Choong, P.F.M.

2004-01-01

Introduction: Thallium-201 scintigraphy is routinely performed on all patients presenting to the bone and soft tissue sarcoma service at St. Vincent's Hospital Melbourne. Methods: As part of the multimodality approach to patients presenting to the service, Thallium-201 planar images are obtained at 30 minutes following a resting injection of tracer with delayed planar and where possible SPECT images at 4 hours. Uptake is qualitatively assessed using adjacent muscle uptake at the time of the scan. All thallium-201 scans are read in conjunction with the correlative structural images performed. Results: High grade bone and soft tissue sarcomas typically show significant retention of tracer relative to background activity and adjacent anatomically structures. Benign lesions may show early activity but typically washout on the delayed images. However, some lesions may show marked thallium-201 activity which will be discussed. At our institution the thallium-201 scans are used for assessment of metabolic activity and tumour grade, planning of image guided pre-treatment biopsies and monitoring of treatment response particularly following radiotherapy. Conclusion: Thallium-201 scintigraphy plays a vital role in assessment and management of bone and soft tissue tumours at our institution. (authors)

Comparison of rest and exercise thallium-201 kinetics in man and implications for quantitation

International Nuclear Information System (INIS)

Freeman, M.R.; Kanwar, N.; Armstrong, P.W.

1989-01-01

To develop a technique for quantitative analysis of resting thallium scintigrams, an understanding of thallium kinetics at rest is required. This study evaluates in normal man the thallium distribution and washout rates of thallium at rest and compares these findings to similar data obtained during exercise. The thallium half-life in normal resting myocardium is significantly longer than after exercise, 10.2 +/- 1.4 hours versus 3.9 +/- 0.3 hours (P less than .01). Differences in resting thallium half-life exist between the anterior, 45 degrees left anterior oblique (LAO), and 70 degrees LAO views and are 11.4 +/- 1.0, 10.6 +/- 1.0, 8.8 +/- 0.7 hours, respectively (all significantly different from each other by ANOVA, P less than or equal to .01); these differences are related to the imaging sequence. After exercise, the thallium half-life also varies according to imaging sequence, but in the opposite direction; i.e., anterior, 45 degrees LAO, and 70 degrees LAO views are 3.6 +/- 0.1, 3.9 +/- 0.3, 4.2 +/- 0.3 hours, respectively (P less than or equal to .01). Since imaging sequence and time of acquisition at rest and exercise were similar, this finding may be related to earlier maximal uptake of thallium after exercise as compared to rest. There are also significant segmental differences in thallium half-life at rest in the 45 degrees LAO view (9.8 +/- 0.9, septal vs. 11.0 +/- 0.9, posterolateral, P less than .01) and 70 degrees LAO view (8.3 +/- 0.4, anteroseptal vs. 9.2 +/- 0.6, inferior, P less than or equal to .01)

Formulation of Dipyridamole Sustained Release Tablet Using Floating System

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Lenny Mauilida Valentina

2011-06-01

Full Text Available Dipyridamole is a drug for prevention of postoperative thromboembolic complication of heart valve replacement and long term therapy of angina pectoris will be well absorbed in stomach. To maintain therapeutic plasma concentration in long time and to increase bioavalaibility is needed a sustained release dosage form having the long residence time in the stomach. The objective of this research was to make floating sustained release tablet of dipyridamole conforming to the requirement that was set up by dipyridamol therapeutic concentration. Tablets were made by wet granulation method using aquadest as a liquid binder, HPMC K4M, Ac-di-sol, Avicel PH 102, talk, and Mg stearat. Dissolution assay was carried out using type 2 release tester at rotation speed of 50 rpm in medium 900 mL HCl 0.1 N at 37 ± 0.5 °C for 8 hours. The formulation containing of 50 mg dipirydamole, HPMC K4M (30%, Ac-di-sol (20%, Avicel PH 102 (37%, talk (2%, and Mg stearat (1% released 59.61 ± 6.73% and 89.34 ± 5.87% of dipyridamole respectively after 4 and 8 hours that conformed to the requirement.

Comparison of the distribution of some thallium chemical species in mice

International Nuclear Information System (INIS)

Petitjean, Francoise.

Scintigraphic images obtained after injection of radioactive thallium show a strong uptake on the kidneys but also on the intestines, which means that quantitative interpretation of the kidney images is troubled by the superposition of these organs. This study is an attempt to find a chemical form of thallium tending less to fix on the intestinal mucous membrane but keeping its affinity for the medullary zone of the kidney. Various agents forming stable complexes with the metal were investigated. Radiothallium is generally used in the chemical form of monovalent thallium chloride. However the degree of oxidation I is unsuitable for stable complex formation and therefore trivalent thallium was also used. Separation of Tl(I) and Tl(III) with ion exchange resin showed the instability of trivalent chloride at low concentration and when the solution is more than 2 hours old the trivalent thallium solutions injected are 10 -5 M. Calculation of the complex formation constants revealed the absence or formation of monovalent thallium complexes. In all monovalent thallium solutions (with or without carrier, with EDTA or HEDTA) the predominant chemical species is Tl + . In the case of trivalent thallium three solutions with carrier were used; the predominant species is TlCl 6 3- when the solution contains Cl - and EDTA and TlEDTA when Cl - , NO 3 - and EDTA are present. These solutions were injected intraveinously into mice in order to study the radiothallium distribution in the kidney and intestine by comparison with that of TlCl while the chemical species varied from one preparation to another no great difference in the radiothallium distribution was observed [fr

Role of exercise thallium-201 myocardial perfusion scintigraphy in predicting prognosis in suspected coronary artery disease

International Nuclear Information System (INIS)

Koss, J.H.; Kobren, S.M.; Grunwald, A.M.; Bodenheimer, M.M.

1987-01-01

While exercise thallium imaging has improved sensitivity and specificity for detection of coronary artery disease (CAD), its predictive value for morbid cardiac events is unclear. Of 532 consecutive patients who underwent exercise thallium imaging, follow-up was complete in 515 (97%) after an average of 36 months (range 31 to 48). Two hundred six patients had an abnormal exercise thallium response and 309 had a normal response. Twenty morbid cardiac events occurred (13 deaths and 7 acute myocardial infarctions [AMI]). Of the 13 patients who died, 12 had abnormal thallium results. Overall, 5.8% of the patients with abnormal thallium results died, in contrast to 0.3% of patients with normal results. Of the 7 patients who had a nonfatal AMI, 3 had abnormal exercise thallium results. Moreover, similar proportions of patients (1.4% and 1.3%) with normal and abnormal exercise thallium results had nonfatal AMI. Presence or absence of pathologic Q waves and inclusion of exercise electrocardiographic results did not significantly alter the results. Thus, although a normal exercise thallium response significantly reduces the likelihood of cardiovascular death, its predictive value for nonfatal AMI is limited. Moreover, the relatively low event rate for patients with a positive exercise thallium response further limits its prognostic value

Thallium-201 exercise myocardial imaging to evaluate myocardial perfusion after coronary artery bypass surgery

International Nuclear Information System (INIS)

Hirzel, H.O.; Nuesch, K.; Sialer, G.; Horst, W.; Krayenbuehl, H.P.

1980-01-01

To assess the usefulness of thallium-201 exercise scintigraphy in evaluating myocardial perfusion after coronary artery bypass surgery, imaging was performed after submaximal bicycle ergometry and at rest in 54 patients before and within 24 +- 10 (SD) weeks after operation. Scintigraphy identified 8 out of 20 patients who were symptom free after operation and showed normal exercise electrocardiograms as still having exercise-induced ischaemia and thus as having not truly benefited from the surgical intervention. In contrast, improvement in perfusion was documented in 17 out of 31 patients despite further complaints of chest pain and persistence of a pathological exercise electrocardiogram in 6 of them. Bypass graft patency rate paralleled the scintigraphic findings in the 35 patients who were restudied arteriographically. It was concluded that thallium-201 exercise scintigraphy is a useful technique to document changes in regional perfusion after surgery and is definitely superior to the clinical evaluation of patients including the exercise electrocardiogram. (author)

Analysis of the degree of pulmonary thallium washout after exercise in patients with coronary artery disease

International Nuclear Information System (INIS)

Levy, R.; Rozanski, A.; Berman, D.S.; Garcia, E.; Van Train, K.; Maddahi, J.; Swan, H.J.

1983-01-01

An abnormal increase in pulmonary thallium activity may be visualized on post-stress thallium images in patients with coronary artery disease. Because this increased pulmonary thallium activity usually disappears by the time of redistribution imaging, this study was designed to assess whether measurement of the degree of pulmonary thallium washout between stress and redistribution might improve the detection of increased pulmonary thallium activity in patients with coronary artery disease. Quantitative analysis revealed abnormal (that is, greater than 2 standard deviations of normal values) pulmonary thallium washouts in 59 (64%) of 92 patients with coronary artery disease, but in only 2 (25%) of 8 subjects with angiographically normal arteries (p less than 0.06). By comparison, the visual analysis of pulmonary thallium washout and use of initial pulmonary to myocardial thallium ratio were significantly (p less than 0.05) less sensitive in detecting abnormality in patients with coronary artery disease. Abnormal pulmonary thallium washout was related to both the anatomic extent and functional severity of disease: it occurred with greatest frequency in patients with multivessel disease and in those with exercise-induced left ventricular dysfunction (p less than 0.005). When added to the quantitative analysis of myocardial scintigraphy, the analysis of pulmonary thallium washout increased the detection of coronary artery disease from 84 to 93% (p less than 0.05), but the sample size was too small to assess specificity

Influence of peak exercise heart rate on normal thallium-201 myocardial clearance

International Nuclear Information System (INIS)

Kaul, S.; Chesler, D.A.; Pohost, G.M.; Strauss, H.W.; Okada, R.D.; Boucher, C.A.

1986-01-01

Measurement of myocardial clearance rates between initial and delayed images is a major justification for adding computer quantification to the interpretation of exercise 201 TI images. To clarify the range of normal thallium clearance and its relationship to the level of exercise achieved, exercise thallium images in 89 normal subjects were analyzed: 45 asymptomatic subjects with less than 1% probability of coronary artery disease (CAD) (Group I), and 44 patients with chest pain found to have no significant CAD on angiography (Group II). Mean initial regional thallium uptake was similar in the two groups, but myocardial thallium clearance (mean +/- 1 s.d.) was slower in Group II, expressed as a longer half-life in the myocardium (8.2 +/- 7.6 hr compared with 3.4 +/- 0.7 hr p less than 0.001). Analysis of variance using ten clinical and exercise variables as covariates showed that the slower clearance in Group II was related to a lower peak exercise heart rate (HR) (154 +/- 27 compared with 183 +/- 11, respectively, p less than 0.001). By linear regression analysis, a decrease in peak HR of 1 beat/min was associated with a slower thallium clearance (longer half-life) of 0.05 hr. Using this formula, the clearance value in each patient was then corrected for peak exercise heart rate by decreasing measured clearance by 0.05 hr multiplied by the amount peak exercise heart rate which was below 183 (the mean value in Group I). There were no differences in the corrected clearance between the two groups. We conclude that thallium myocardial clearance after exercise is related in part to factors other than the presence of CAD, being slower when peak exercise HR is lower. Therefore, thallium clearance rates alone uncorrected for peak exercise heart rate should be used with caution when diagnosing CAD

Detection of viability by percent thallium uptake with conventional thallium scintigraphy

International Nuclear Information System (INIS)

Imai, Kamon; Araki, Yasushi; Horiuchi, Kou-ichi; Yumikura, Sei; Saito, Satoshi; Ozawa, Yukio; Kan-matsuse, Katsuo; Hagiwara, Kazuo.

1994-01-01

Thallium myocardial scintigraphy (TMS) is used for diagnosis of viability in infarcted myocardium before coronary revascularization. Underestimation of viability by TMS has been reported by many investigators. To evaluate viability precisely, thallium re-injection method or 24 hour delayed imaging is performed. However, these techniques are not convenient and are difficult to perform in clinical practice. Percent T1-uptake method was developed for predicting myocardial viability. To evaluate usefulness of this method, TMS was performed before and after PTCA in 23 patients with myocardial infarction. Left ventricle was divided into 3 layers, then each layer was divided into 4 segments (12 segments in total). Forth three segments showed recovery of perfusion on TMS after PTCA. Viability in infarcted myocardium is predicted by 1) redistribution (RD), 2) %T1-uptake≥45% on the image immediately after exercise (TE), and 3) %T1-uptake≥45% on delayed image (TD). Sensitivity was RD: 60%, TE: 90% and TD: 95% (p<0.001 vs. RD). Specificity was RD: 74%, TE: 68%, and TD: 60% (NS). Predictive accuracy (PA) was RD: 69%, TE: 77%, TD: 73% (NS). Compared with RD, %T1-uptake, either TE or TD, increased sensitivity with slightly improved PA, but decreased specificity slightly. Therefore %T1-uptake would be a sensitive and useful predictor to find patients who are most likely to benefit from re-vascularization. (author)

Late reversibility of tomographic myocardial thallium-201 defects: an accurate marker of myocardial viability

International Nuclear Information System (INIS)

Kiat, H.; Berman, D.S.; Maddahi, J.; De Yang, L.; Van Train, K.; Rozanski, A.; Friedman, J.

1988-01-01

Twenty-one patients were studied who underwent thallium-201 stress-redistribution single photon emission computed tomography (SPECT) both before and after coronary artery bypass grafting (n = 15) or transluminal coronary angioplasty (n = 6). All patients underwent thallium imaging 15 min, 4 h and late (18 to 72 h) after stress as part of the preintervention thallium-201 scintigram. In a total of 201 tomographic myocardial segments with definite post-stress thallium-201 perfusion defects in which the relevant coronary arteries were subsequently successfully reperfused, the 4 h redistribution images did not predict the postintervention scintigraphic improvement: 67 (85%) of the 79 4 h reversible as well as 88 (72%) of the 122 4 h nonreversible segments improved (p = NS). The 18 to 72 h late redistribution images effectively subcategorized the 4 h nonreversible segments with respect to postintervention scintigraphic improvement: 70 (95%) of the 74 late reversible segments improved after intervention, whereas only 18 (37%) of the 48 late nonreversible segments improved (p less than 0.0001). The frequency of late reversible defects and the frequency of postrevascularization improvement of late nonreversible defects are probably overestimated by this study because of referral biases. The cardiac counts and target to background ratios from late redistribution studies resulted in satisfactory cardiac images for visual interpretation. For optimal assessment of the extent of viable myocardium by thallium-201 scintigraphic studies, late redistribution imaging should be performed when nonreversible defects are observed on 4 h redistribution images

Comparison of thallium-201 and gallium-67 scintigraphy in soft tissue and bone marrow multiple myeloma: a case report

International Nuclear Information System (INIS)

Roach, P.J.; Arthur, C.K.

1997-01-01

A 68 year old female was referred for assessment of multiple myeloma. A large myelomatous infiltrate involving the left triceps muscle showed avid uptake on both thallium-201 and gallium-67 scintigraphy. Following radiotherapy, imaging with both radiopharmaceuticals showed resolution of disease; however, tumour recurrence in the bone marrow was seen only on thallium-201 imaging. This observation suggests that while soft-tissue myleoma shows similar appearances on thallium-201 and gallium-67 scintigraphy, both at baseline and following therapy, gallium-67 may not demonstrate bone marrow infiltration which is visualized on thallium-201 imaging. Therefore, thallium-201 appears to be superior to gallium-67 in evaluation of patients with multiple myeloma when soft tissues and bone marrow are involved. 17 refs., 3 figs

Thallium-201 scintigraphy for bone and soft tissue tumors

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Tokuumi, Yuji; Tsuchiya, Hiroyuki; Sunayama, Chiaki; Matsuda, Eizo; Asada, Naohiro; Taki, Junichi; Sumiya, Hisashi; Miyauchi, Tsutomu; Tomita, Katsuro [Kanazawa Univ. (Japan). School of Medicine

1995-05-01

This study was undertaken to assess the usefulness of thallium-201 scintigraphy in bone and soft tissue tumors. Pre-therapy scintigraphy was undertaken in a total of 136 patients with histologically confirmed diagnosis, consisting of 74 with malignant bone and soft tissue tumors, 39 with benign ones, 12 with diseases analogous to tumors, and 11 others. Thallium activity was graded on a scale of 0-4: 0=background activity, 1=equivocal activity, 2=definitive activity, but less than myocardium, 3=definite activity equal to myocardium, and 4=activity greater than myocardium. In the group of malignant tumors, thallium-201 uptake was found in 80%, although it was low for chondrosarcoma (2/8) and malignant Schwannoma (one/3). The group of benign tumors, however, showed it in only 41%, being restricted to those with giant cell tumors, chondroblastoma, fibromatosis, and osteoid osteoma. Thallium-201 uptake was also found in all 8 patients with metastatic tumors. In 23 patients undergoing thallium imaging before and after chemotherapy, scintigraphic findings revealed a high correlation with histopathological findings. Thus, thallium-201 scintigraphy may be potentially used to distinguish malignant from benign bone and soft tissue tumors, except for a few histopathological cases, as well as to determine loco-regional metastases and response to chemotherapy. (N.K.).

Intracoronary thallium-201 assessment of thrombolysis in acute myocardial infarction: a technique for imaging thallium distribution before and after therapy

International Nuclear Information System (INIS)

Parker, J.A.; Markis, J.E.; Silverman, K.J.

1982-01-01

Intracoronary administration of streptokinase during the acute phase of myocardial infarction results in recanalization of the occluded coronary artery in a high percentage of patients. A technique is developed to investigate the acute effect of thrombolysis on the perfusion to viable myocardium using intracoronary administration of thallium-201. With intracoronary administration a very small initial dose of thallium can be used. Thus, a second scan can be performed after therapy, using a normal dose with only minimal contribution from the baseline study

Comparison of electrocardiography and thallium-201 myocardial scintigraphy for the detection of ergonovine-induced coronary artery spasm: angiographic correlation

International Nuclear Information System (INIS)

Shanes, J.G.; Pavel, D.; Blend, M.

1987-01-01

This study was performed to determine the sensitivity of thallium imaging vs ECG monitoring for detecting coronary artery spasm noninvasively following intravenous ergonovine administration as compared to simultaneous coronary angiography. Thirty-two patients with insignificant coronary artery disease and chest pain underwent 12-lead ECG monitoring, thallium imaging, and coronary arteriography following the administration of 0.05, 0.1, 0.2, and 0.3 mg of ergonovine given 5 minutes apart or until chest pain occurred. One minute following the last dose of ergonovine, 2.5 mCi of thallium-201 was injected intravenously, and a final ECG was recorded and repeat coronary arteriography performed. Within 10 minutes following the injection of thallium, imaging was performed in the 40-degree and 70-degree left anterior oblique and anterior projections. The ECG, thallium study, and coronary arteriogram were read blindly and results were compared. The ECG, angiogram, and thallium study were read as positive if the following occurred, respectively: greater than or equal to 1 mm ST segment elevation, depression, or T wave reversal; greater than 50% vessel narrowing,; and reversible perfusion defect. Five patients were excluded from analysis because of either catheter-induced spasm, suboptimal thallium studies, or protocol violations. Of the 27 patients included for analysis, six had chest pain, five had a positive angiogram, five had a positive thallium study, and one had a positive ECG. The sensitivity of thallium vs ECG monitoring was 80% vs 25%, and the accuracy was 92% vs 80%. We conclude that thallium imaging greatly increases the noninvasive detection of ergonovine-induced coronary spasm as compared with the ECG with no loss of accuracy

Thallium poisoning. Diagnosis may be elusive but alopecia is the clue.

Science.gov (United States)

Moore, D; House, I; Dixon, A

1993-01-01

Thallium is a heavy metal whose salts are used in some rodent poisons and in the manufacture of optical lenses, semiconductors, scintillation counters, low temperature thermometers, and switching devices, green coloured fireworks, and imitation jewelery, and as chemical catalysts. In clinical practice thallium isotopes are used in cardiac scanning, but the use of thallium salts to treat scalp ringworm was abandoned earlier this century because of their toxicity. The sale of thallium in Britain is strictly licensed because of its toxicity and potential for use in murder, which is helped by the fact that thallous salts are colourless, tasteless, and odorless. The more water soluble salts (such as thallium sulphate, acetate, or carbonate) have higher toxicity, and although the toxic dose is variable most deaths occur after the ingestion of 10-15 mg/kg of soluble salt. Most cases of thallium toxicity occur after oral ingestion but severe toxicity has been reported after inhalation of contaminated dust from pyrite burners, in zinc and lead smelting, and in the manufacture of cadmium, after dermal absorption through protective rubber gloves, and after snorting what was thought to be cocaine. The elimination half time of thallium is between 1.7 and 30 days depending on the time since, and chronicity of, ingestion. The elimination time phases are apparent and because of the long terminal elimination half time thallium may act as a cumulative poison. We present two cases of thallium poisoning with intent to kill. Images FIG 3 PMID:8518684

Preoperative evaluation of malignancy of glioma by thallium-201 SPECT, proton MRS and 18F-fluorodeoxy-glucose PET

International Nuclear Information System (INIS)

Ito, Tamio; Nakagawara, Jyoji; Sasaki, Takehiko; Nakamura, Hirohiko; Tsukamoto, Eriko

2005-01-01

We studied preoperative malignancy evaluation of glioma by thallium-201 SPECT (T1-SPECT), proton MRS (MRS) and 18F-fluorodeoxy-glucose PET (FDG-PET). Twenty-seven patients with astrocytic tumors (diffuse astrocytoma (A): 8, anaplastic astrocytoma (AA): 10, glioblastoma (GB): 9) were retrospectively studied. FDG-PET was assessed as the visual metabolic grading scale (MG Scale) in 9 cases. The Tl index was expressed as the count rate of the tumor site to the count rate over the contralateral normal region in 25 cases. MRS was evaluated as the metabolite ratios of choline/creatine (Cho/Cr) and Cho/N-acetylaspartate (NAA), and as the presence of lactate and lipid metabolites in 23 cases. As the malignancy grade of the glioma rises, so too did the MG Scale of FDG-PET and Tl index (PET MG Scale (A: Grade (Gr). 1; 2 cases, Gr.2; 2 cases, AA: Gr.1; 1 case, Gr.2; 1 case, GB: Gr.2; 2 cases, Gr.3; 1 case), Tl index: A:129±0.22, AA: 1.97±0.44, GB: 342±1.38). Metabolite ratios of Cho/Cr and Cho/NAA in the high-grade gliomas were higher than those in the low-grade gliomas, however, those of GB were lower than those of AA, maybe due to difficulty in the spectroscopic voxel selection (Cho/Cr: A:1.86, AA: 2.96, GB: 2.73, Cho/NAA: A: 2.90, AA: 6.37, GB: 5.57). Both lactate and lipids presented in the high-grade glioma cases. Proliferative potential as measured by MIB-1 index mostly correlated with the Tl index significantly (p=0.0002). We were able to evaluate the malignancy grade of gliomas preoperatively by using FDG-PET, Tl-SPECT and MRS, however, we also need to understand the pitfalls of each of these examinations respectively (author)

Slow late myocardial clearance of thallium: a characteristic phenomenon in coronary artery disease

International Nuclear Information System (INIS)

Sklar, J.; Kirch, D.; Johnson, T.; Hasegawa, B.; Peck, S.; Steele, P.

1982-01-01

Researchers extended the quantitative seven-pinhole method to follow the dynamics of thallium redistribution after exercise. Researchers observed a pattern of slow late thallium clearance that appears to be characteristic of myocardium supplied by obstructed coronary arteries. In 28 subjects, quantitative thallium scintigrams and blood samples for thallium concentration were taken immediately, 2 hours and 4 hours after maximal treadmill exercise. Twenty subjects had coronary artery disease (CAD) and eight were normal. The rate of thallium clearance from the blood (TCB) was compared with the rate of thallium clearance from each segmental region of myocardium between the 2- and 4-hour images. In seven of the eight normal subjects, TCM exceeded TCB in all regions of all images. Seventeen of the 20 CAD patients had at least one region where TCM was less than TCB. Of the 13 patients with multivessel CAD 11 had multiple regions with TCM less than TCB. Using this criterion, we detected 31 of 39 obstructed coronary arteries. Of the 37 regions that were abnormal by this analysis, 30 corresponded to obstructed coronary arteries. In contrast, while conventional circumferential count profile analysis also was abnormal in 17 of the 20 CAD patients, it diagnosed multivessel CAD in only five of the 13 patients that had it. These results show that slow late thallium clearance from myocardium is characteristic of regions of myocardium supplied by diseased coronary arteries and that observation of this phenomenon may improve diagnostic sensitivity for the presence of multivessel CAD

Prospective assessment of regional myocardial perfusion before and after coronary revascularization surgery by quantitative thallium-201 scintigraphy

International Nuclear Information System (INIS)

Gibson, R.S.; Watson, D.D.; Taylor, G.J.; Crosby, I.K.; Wellons, H.L.; Holt, N.D.; Beller, G.A.

1983-01-01

Because thallium-201 uptake relates directly to the amount of viable myocardium and nutrient blood flow, the potential for exercise scintigraphy to predict response to coronary revascularization surgery was investigated in 47 consecutive patients. All patients underwent thallium-201 scintigraphy and coronary angiography at a mean (+/- standard deviation) of 4.3 +/- 3.1 weeks before and 7.5 +/- 1.6 weeks after surgery. Thallium uptake and washout were computer-quantified and each of six segments was defined as normal, showing total or partial redistribution or a persistent defect. Persistent defects were further classified according to the percent reduction in regional thallium activity; PD25-50 denoted a 25 to 50% constant reduction in relative thallium activity and PD greater than 50 denoted a greater than 50% reduction. Of 82 segments with total redistribution before surgery, 76 (93%) showed normal thallium uptake and washout postoperatively, versus only 16 (73%) of 22 with partial redistribution (probability [p] . 0.01). Preoperative ventriculography revealed that 95% of the segments with total redistribution had preserved wall motion, versus only 74% of those with partial redistribution (p . 0.01). Of 42 persistent defects thought to represent myocardial scar before surgery, 19 (45%) demonstrated normal perfusion postoperatively. Of the persistent defects that showed improved thallium perfusion postoperatively, 75% had normal or hypokinetic wall motion before surgery, versus only 14% of those without improvement (p less than 0.001). Whereas 57% of the persistent defects that showed a 25 to 50% decrease in myocardial activity demonstrated normal thallium uptake and washout postoperatively, only 21% of the persistent defects with a decrease in myocardial activity greater than 50% demonstrated improved perfusion after surgery (p . 0.02)

Quantitative assessment of thallium myocardial washout rate: Importance of peak heart rate and lung thallium uptake in defining normal values

International Nuclear Information System (INIS)

Nishimura, Tsunehiko; Uehara, Toshiisa; Hayashida, Kohei; Kozuka, Takahiro; Saito, Muneyasu; Sumiyoshi, Tetsuya; National Cardiovascular Center, Suita, Osaka

1987-01-01

Traditionally, the results of exercise thallium scintigraphy were interpreted by transient defect analysis using initial and delayed images. Recently, washout rate analysis has been used for the relative quantification of exercise thallium scintigraphy. A diffuse slow washout from all myocardial regions has been defined as the indicator of extensive coronary artery disease. However, slow washout has occasionally been observed in normal cases and in healthy myocardial segments which are not supplied by a stenosed artery in patients with single or double vessel disease. We evaluate the factors influencing washout rate in 100 normal patients and 63 patients with angina pectoris (33 cases of single vessel disease and 30 cases of double vessel disease). The washout rates were calculated using circumferential profile analysis. In normal patients, washout rate was closely related to peak heart rate (r=0.72) and inversely related to lung thallium uptake (r=-0.56). A diffuse slow washout was observed in seven (7%) of 100 normal patients, six (18%) of 33 cases of single vessel disease and eight (24%) of 30 cases of double vessel disease. The patients with diffuse slow washout showed significantly higher lung thallium uptake values and lower peak heart rates than those without diffuse slow washout (P<0.01). Thus, this false positive slow washout should be considered in the interpretation of quantitative exercise thallium scintigraphy. (orig.)

Left ventricular aneurysm in short axis: a comparison of magnetic resonance, ultrasound and thallium-201 SPECT images

International Nuclear Information System (INIS)

Ahmad, M.; Johnson, R.F. Jr.; Fawcett, H.D.; Schreiber, M.H.

1987-01-01

Short axis magnetic resonance images of a left ventricular aneurysm were compared to similar views obtained by echocardiography and by thallium-201 single photon emission computed tomography. Images of the dyskinetic left ventricular apex and the contractile left ventricular base were analyzed and compared. Unlike the previously reported orthogonal plane magnetic resonance images, short axis imaging provided representative and quantitative information in views comparable to those obtained by standard noninvasive imaging techniques. These data indicate that short axis magnetic resonance imaging is capable of identifying and sizing the aneurysmal and the residual segments of the left ventricle. The findings may be of prognostic value in patients with left ventricular aneurysm

Markerless registration for image guided surgery. Preoperative image, intraoperative video image, and patient

International Nuclear Information System (INIS)

Kihara, Tomohiko; Tanaka, Yuko

1998-01-01

Real-time and volumetric acquisition of X-ray CT, MR, and SPECT is the latest trend of the medical imaging devices. A clinical challenge is to use these multi-modality volumetric information complementary on patient in the entire diagnostic and surgical processes. The intraoperative image and patient integration intents to establish a common reference frame by image in diagnostic and surgical processes. This provides a quantitative measure during surgery, for which we have been relied mostly on doctors' skills and experiences. The intraoperative image and patient integration involves various technologies, however, we think one of the most important elements is the development of markerless registration, which should be efficient and applicable to the preoperative multi-modality data sets, intraoperative image, and patient. We developed a registration system which integrates preoperative multi-modality images, intraoperative video image, and patient. It consists of a real-time registration of video camera for intraoperative use, a markerless surface sampling matching of patient and image, our previous works of markerless multi-modality image registration of X-ray CT, MR, and SPECT, and an image synthesis on video image. We think these techniques can be used in many applications which involve video camera like devices such as video camera, microscope, and image Intensifier. (author)

Prognostic value of exercise thallium-201 imaging in patients presenting for evaluation of chest pain

International Nuclear Information System (INIS)

Brown, K.A.; Boucher, C.A.; Okada, R.D.; Guiney, T.E.; Newell, J.B.; Strauss, H.W.; Pohost, G.M.

1983-01-01

Accurate prognostic information is important in determining optimal management of patients presenting for evaluation of chest pain. In this study, the ability of exercise thallium-201 myocardial imaging to predict future cardiac events (cardiovascular death or nonfatal myocardial infarction) was correlated with clinical, coronary and left ventricular angiographic and exercise electrocardiographic data in 139 consecutive, nonsurgically managed patients followed-up over a 3 to 5 year period (mean follow-up, 3.7 +/- 0.9), using a logistic regression analysis. Among patients without prior myocardial infarction (100 of 139), the number of myocardial segments with transient thallium-201 defects was the only statistically significant predictor of future cardiac events when all patient variables were evaluated. Among patients with myocardial infarction before evaluation (39 of 139), angiographic ejection fraction was the only significant predictor of future cardiac events when all variables were considered. This study suggests an approach to evaluate the risk of future cardiac events in patients with possible ischemic heart disease

Dipyridamole may induce migraine in patients with migraine without aura

DEFF Research Database (Denmark)

Kruuse, C; Lassen, L H; Iversen, Helle Klingenberg

2006-01-01

Dipyridamole inhibits phosphodiesterase 5 (PDE5) and adenosine re-uptake. The most prominent side-effect is headache. We examined the migraine-generating effects of dipyridamole as well as the cerebral blood velocity response in a single-blind study, including 10 patients with migraine without aura...... repeatedly. Headache was induced in all migraine patients and in eight of 10 healthy subjects (P = 0.47) with no significant difference in headache intensity (P = 0.53). However, five patients but only one healthy subject experienced the symptoms of migraine without aura, according to ICHD-2 criteria, within....... Thus, dipyridamole induces symptoms of migraine and an initial decrease in V(mca) in migraine patients, but not significantly more than in healthy subjects. This relatively low frequency of migraine induction, compared with nitric oxide donors and sildenafil, is probably due to the less specific action...

The clinical role of thallium-201 scintigraphy in the management and prognosis of coronary artery disease

International Nuclear Information System (INIS)

Gammage, M.D.; Murray, D.P.; Rafiqi, E.; Murray, R.G.

1984-01-01

To determine the clinical impact of thallium-201 scintigraphy in coronary artery disease, the indications, diagnostic yield and contribution to patient management were reviewed retrospectively in 103 patients referred for routine investigations. Exercise and redistribution image data were collected in multiple projections and interpreted by visual and semi-quantitative means. A segmental image defect was accepted as indicating the presence of coronary artery disease. Thallium-201 scintigraphy was performed as a diagnostic procedure in 71 patients (69%) who had equivocal evidence of coronary artery disease. In 57 (80%) of these patients, thallium-201 scintigraphy was normal and 53 (75%) were spared diagnostic coronary arteriography. Despite normal thallium-201 scintigrams, arteriography was performed in 4 patients with persisting symptoms and demonstrated normal vessels in 2 patients and single vessel disease in 2 patients. Conversely, arteriography was normal in 2 of 14 patients (14%) with unequivocal image defects. Thallium-201 scintigraphy was performed as a functional complement to coronary arteriography in 32 patients, influencing the decision for coronary surgery in 10, for angioplasty in 4 and against surgery in 2. Myocardial ischaemia was confirmed in 8 and refuted in 8 patients with questionable arteriographic coronary disease. Positive management decisions were taken as a result of thallium-201 scintigraphy in 80 of these 103 patients (78%). These data confirm the vital role of thallium-201 scintigraphy in the evaluation and management of patients with suspected and proven coronary artery disease. (orig.)

Indications of laparoscopic cholecystectomy based on preoperative imaging findings

International Nuclear Information System (INIS)

Wakizaka, Yoshitaka; Sano, Syuichi; Nakanishi, Yoshimi; Koike, Yoshinobu; Ozaki, Susumu; Iwanaga, Rikizo; Uchino, Junichi.

1994-01-01

We studied the indications for laparoscopic cholecystectomy (LC) and values of preoperative imaging findings in 82 patients who underwent preoperative imaging diagnostic tests (abdominal echogram, abdominal CAT scan, ERCP). We analyzed mainly patients who were considered to be indicated for LC but whose gallbladders could be removed by open laparotomy, or whose gallbladders were removed by open laparotomy but were considered indicated for LC from retrospective study. We found the following results. LC could be easily performed in patients with a history of severe acute cholecystitis if they had no findings of a thickened wall or negative gallbladder signs. Abdominal echogram and CAT scan were the best preoperative imaging tests for determining the gallbladder's state, especially for obstruction of the cystic duct. These results are important today when the operative indications of LC are extremely indefinite because of the accumulation of operative experience and technological improvements. (author)

Importance of preoperative imaging in acetabular revision surgery - a case report.

Science.gov (United States)

Schmitz, Hc; Egidy, Cc; Al-Khateeb, H; Cárdenas, G; Gehrke, T; Kendoff, D

2012-01-01

Acetabular defects, particularly as a result of protrusion of acetabular components into the hemipelvis, may cause serious complications during revision procedures as a result of iatrogenic injury to surrounding anatomical structures. In these challenging cases, we advocate the utilisation of preoperative three dimensional imaging. MRI and CT- imaging offer superior understanding of the three-dimensional quality of bony defects and the relationship of implants to important anatomical structures. Appropriate preoperative planning may also prevent major complications during the removal of the pre-existing hardware, prior to re-implantation of implants. Potential complications include injury of nerves, blood vessels and other intrapelvic structures.In our case, a major bony defect of the acetabulum was a result of the protrusion of an implanted reinforcement ring. A preoperative, contrast-enhanced CT scan showed that the urethra was in close proximity to the hook of the reinforcement ring.The preoperative imaging aided in identifying and understanding the potential complications that could occur intraoperatively. Additionally, it delineated the intact anatomic structures prior to surgery, which could have medico-legal implications.The importance of preoperative imaging and the existing literature is discussed within this case description.

SYNCHROTRON X-RAY ABSORPTION-EDGE COMPUTED MICROTOMOGRAPHY IMAGING OF THALLIUM COMPARTMENTALIZATION IN IBERIS INTERMEDIA

Science.gov (United States)

Thallium (TI) is an extremely toxic metal which, due to its similarities to K, is readily taken up by plants. Thallium is efficiently hyperaccumulated in Iberis intermedia as TI(I). Distribution and compartmentalization of TI in I. intermedia is highes...

Self-microemulsifying drug delivery system for improved oral bioavailability of dipyridamole: preparation and evaluation.

Science.gov (United States)

Guo, Feng; Zhong, Haijun; He, Jing; Xie, Baogang; Liu, Fen; Xu, Helin; Liu, Minmin; Xu, Chunlian

2011-07-01

Dipyridamole shows poor and variable bioavailability after oral administration due to pHdependent solubility, low biomembrane permeability as well as being a substrate of P-glycoprotein. In order to improve the oral absorption of dipyridamole, a self-microemulsifying drug delivery system (SMEDDS) for dipyridamole was prepared and evaluated in vitro and in vivo. The optimum formulation was 18% oleic acid, 12% Labrafac lipophile WL 1349, 42% Solutol HS 15 and 28% isopropyl alcohol. It was found that the performance of self-microemulsification with the combination of oleic acid and Labrafac lipophile WL 1349 increased compared with just one oil. The results obtained from an in vitro dissolution assay indicated that dipyridamole in SMEDDS dissolved rapidly and completely in pH 6.8 aqueous media, while the commercial drug tablet was less soluble. An oral bioavailability study in rats showed that dipyridamole in the SMEDDS formulation had a 2.06-fold increased absorption compared with the simple drug suspension. It was evident that SMEDDS may be an effective approach to improve the oral absorption for drugs having pH-dependent solubility.

Clinical features and applications of thallium-201. With reference to scintigraphy

Energy Technology Data Exchange (ETDEWEB)

Fujii, Tadashige

1988-12-01

Thallium-201 is not only used widely in myocardial imaging but also has a great potential in other various nuclear medicine imaging studies. This paper presents clinical features and applications of thallium-201, focusing on clinical trials with thallium-201 at the Shinshu University School of Medicine. Thallium-201 myocardial scintigraphy offers information on (1) ventricular position and morphology, (2) hypertrophy or dilatation of the left ventricle, (3) hypertrophy or dilatation of the right ventricle, (4) site and extent of myocardial ischemia and infarct, (5) myocardial blood flow, (6) pulmonary congestion or interstitial pulmonary edema, and (7) pericardial effusion. It can be used in the following evaluation or diagnosis: (1) acute or old myocardial infarction, (2) angina pectoris, (3) treatment strategy or prognosis of ischemic heart disease, (4) treatment strategy or observation of bypass graft or drug therapy, (5) hypertrophic or dilated idiopathic cardiomyopathy, (6) myocardial lesions induced by sarcoidosis, collagen disease, and neuro-muscular disease, (7) ventricular hypertrophy and pulmonary edema, and (9) pericarditis, pericardial effusion, and systolic pericarditis associated with underlying disease. The significance of tumor, liver, bone marrow scintigraphies is also referred to. (Namekawa, K) 69 refs.

Assessing the fate and toxicity of Thallium I and Thallium III to three aquatic organisms.

Science.gov (United States)

Rickwood, C J; King, M; Huntsman-Mapila, P

2015-05-01

Thallium has been shown to significantly increase in both water and aquatic biota after exposure to metal mine effluent, however, there is a lack of knowledge as to its fate and effect in the aquatic environment. The objectives of this project were to assess (1) fate of thallium by conducting speciation analysis and determining the influence of water quality on toxicity and (2) effects of thallium (I) and (III) on three aquatic species; the algae, Pseudokirchneriella subcapitata, the invertebrate Ceriodaphnia dubia and the vertebrate Pimephales promelas. Speciation analysis proved challenging with poor recovery of thallium (I), however analysis with solutions >125μg/L revealed that over a 7-d period, recovery of thallium (III) was less than 15%, suggesting that the majority of thallium (III) was converted to Thallium (I). It was only in fresh solutions where recovery of Thallium (III) was greater than 80%. The lowest IC25s generated during our effects assessment for both Thallium (I) and (III) were more than 10-fold greater than the highest concentration recorded in receiving environments (8μg/L) and more than 100-fold greater than the current guideline (0.8μg/L). To assess the influence of water quality on thallium toxicity, the concentrations of both potassium and calcium were reduced in dilution water. When potassium was reduced for both C. dubia and P. subcapitata tests, the lowest IC25 generated was 5-fold higher than the current guideline, but within the range of concentrations reported in receiving environments for both Thallium (I) and (III). When calcium was reduced in dilution water, toxicity only increased in the Tl (III) tests with C. dubia; the IC25 for Tl(III), similar to the exposures conducted with reduced potassium, was within the range of total thallium concentrations reported in the receiving environment. Without an accurate, repeatable method to assess thallium speciation at low concentrations it is not possible to draw any firm conclusions

Comparison of early thallium-201 scintigraphy and gated blood pool imaging for predicting mortality in patients with acute myocardial infarction

International Nuclear Information System (INIS)

Becker, L.C.; Silverman, K.J.; Bulkley, B.H.; Kallman, C.H.; Mellits, E.D.; Weisfeldt, M.

1983-01-01

The extent of abnormality in early thallium-201 and gated cardiac blood pool scintigrams has been reported to be useful for predicting mortality in patients with acute myocardial infarction (AMI). To compare the two techniques, 91 patients admitted consecutively with evident or strongly suspected AMI underwent both imaging studies within 15 hours of the onset of symptoms. Patients with pulmonary edema or shock were excluded. AMI developed in 84% of patients, and 6-month mortality for the entire group was 16%. A thallium defect score of 7.0 or greater identified a subgroup of 14 patients with 64% 6-month mortality rate. Similarly, a left ventricular ejection fraction of 35% or less identified a high-risk subgroup of 10 patients with a 6-month mortality of 60%. Mortality in the remaining patients was 8% for thallium score less than 7 and 11% for ejection fraction greater than 35%. The mortality rate was highest among patients who had concordant high-risk scintigrams (five of six, 83%), lowest in those with concordant low-risk studies (five of 64, 8%) and intermediate in those with discordant results (four of 11, 36%). Of a number of clinical variables, only the appearance of Q waves, peak creatine kinase greater than 1000 IU/I, and history of infarction were significantly associated with mortality. High-risk thallium or blood pool scintigraphic results were significantly more predictive and a thallium score of 7 or greater was more sensitive for detecting nonsurvivors than ejection fraction 35% or less at a similar level of specificity

Optimization of perfusion studies using Atropine

International Nuclear Information System (INIS)

Alvarado, A.N.; Valle, V.M.; Montoya, M.J.; Eskenazi, E.S.; Montiel, M.L.; Cueto, C.C.

2002-01-01

The studies of myocardial perfusion require an adequate stress; exercise or pharmacological. Every day, more pharmacological studies are performed, specially in some group of patients (women, AMI, etc). There some drugs that are used for this purpose, as adenosine and dobutamine. However, their cost and the lack of availability and infrastructure in our country do not allow there routinely use. We performed dipyridamol as a pharmacological stress, however in some patients there is a doubt regarding if the pharmacological effect was adequate. Atropine is a drug that is frequently used for different purpose and it is well know its tachycardic response. We present and alternative technique, using dipyridamol-atropine as a protocol of stress perfusion study. Our goal was to correlate the standard dipyridamol -thallium perfusion study and the dipyridamol -atropine-perfusion in patients with chronic coronary disease. We evaluated 6 patients (5 males) with stable angina and chronic coronary disease. A standard dipyridamol-thallium study was performed in all of them. Dipyridamole was administered intravenously at a rate of 0.14 mg/kg/min over 6 min for a total of 0.84 mg/kg body weight. Blood pressure, heart rate, EKG and symptoms were monitored before, during and after the pharmacological infusion. Two minutes after the infusion was completed, the radiotracer was injected intravenously. In the next 6 months, without any modification of the clinical situation (symptoms and therapy) a new dipyridamol study was performed, using 1 mg of atropine after the administration of dipyridamol. There were no differences in the collateral effects and we observed and average increase of 30% in the heart rate in relation with the study using dipyridamol alone. The addition of atropine to the standard dipyridamol perfusion study is safe, cheaper and improved the detection of perfusion defects in patients with coronary artery disease

Research for correction pre-operative MRI images of brain during operation using particle method simulation

International Nuclear Information System (INIS)

Shino, Ryosaku; Koshizuka, Seiichi; Sakai, Mikio; Ito, Hirotaka; Iseki, Hiroshi; Muragaki, Yoshihiro

2010-01-01

In the neurosurgical procedures, surgeon formulates a surgery plan based on pre-operative images such as MRI. However, the brain is transformed by removal of the affected area. In this paper, we propose a method for reconstructing pre-operative images involving the deformation with physical simulation. First, the domain of brain is identified in pre-operative images. Second, we create particles for physical simulation. Then, we carry out the linear elastic simulation taking into account the gravity. Finally, we reconstruct pre-operative images with deformation according to movement of the particles. We show the effectiveness of this method by reconstructing the pre-operative image actually taken before surgery. (author)

Comparison of 99mTc-MIBI Myocardial Uptake at Rest with Reinjection and 24-hour after Reinjection Images of 201T1

International Nuclear Information System (INIS)

Bom, Hee Seung; Kim, Ji Yeul; Park, Joo Hyung; Ahn, Young Keun; Jeong, Myung Ho; Cho, Jeong Gwan; Park, Jong Choon; Kang, Jung Chaee

1992-01-01

Clinical role of 99m Tc-MIBI myocardial scintigraphy in the diagnosis of coronary artery disease (CAD) is now well accepted, however, the role of it in the identification of viable myocardium in patients with chronic CAD has not yet been clarified. To determine the usefulness of rest-injected 99m Tc-MIBI scan as a marker of myocardial viability, the regional uptake of this agent at rest was compared with that of '2 01 T1 on reinjection and 24 hours after reinjection images. Subject patients were 13 chronic CAD patients who showed irreversible perfusion defect(s) on standard pharmacologic (dipyridamole) stress-redistribution images. Immediately after the redistribution images were obtained, 37 MBq thallium was injected at rest, and images were reacquired at 10 minutes and 24 hours after reinjection. After then 740 MBq 99m Tc-MIBI was injected, and 1 hour later rest MIBI myocardial imaging was performed. Five sets of images (stress, redistribution, reinjection, delayed images of thallium, and rest image of MIBI) were then analyzed qualitatively and quantitatively. Left ventricle was arbitrarily divided into 9 segments (apex, basal and apical portions of anterior, septal, inferior, and lateral walls). Seven patients and 30 regions showed a fixed perfusion defect on the stress-redistribution images. Among 30 regions, 15 showed positive uptakes and 6 showed negative uptakes on both 201 T1 reinjection/delayed images and 99m Tc-MIBI rest images. Five regions showed only thallium uptake and were regarded as viable clinically. Of four regions which showed only 99m Tc-MIBI uptake, two were regarded as viable, while the other two were regarded as a nonviable scar tissue clinically. In conclusion, 201 T1 reinjection technique was more reliable in the identification of viable myocardium. However, the role of 99m Tc-MIBI in identification of viable myocardium was still remained to be clarified because 2 of 9 regions showed only 99m Tc-MIBI uptake and were regarded as viable

Thallium scintigraphy during dobutamine infusion: nonexercise-dependent screening test for coronary disease

International Nuclear Information System (INIS)

Mason, J.R.; Palac, R.T.; Freeman, M.L.; Virupannavar, S.; Loeb, H.S.; Kaplan, E.; Gunnar, R.M.

1984-01-01

Exercise thallium scintigraphy has proven to be a sensitive method for detecting coronary artery disease (CAD). However, early redistribution of thallium and inadequate exercise can reduce its sensitivity. In this study, dobutamine was infused in incremental doses (5, 10, 15, and 20 micrograms/kg/min) in 24 patients being evaluated for chest pain. Thallium scintigraphy was completed during the maximum dose of dobutamine tolerated and repeated 4 hours later. Significant CAD was present in 16 patients; the remaining eight had normal coronaries. Exercise ECG was obtained in 23 patients. During dobutamine thallium scintigraphy, reversible perfusion defects occurred in 15 of 16 CAD and in one of eight non-CAD patients, resulting in a sensitivity of 94% and a specificity of 87%. Exercise ECG had a sensitivity of 60% and a specificity of 63%. We conclude that: (1) dobutamine thallium scintigraphy appears to be a sensitive method for detecting significant CAD and provided a more sensitive screening test than exercise ECG; (2) dobutamine thallium scintigraphy is especially useful in patients who cannot exercise; and (3) because imaging occurs during dobutamine infusion, the problem of early redistribution may be mitigated

Thallium scintigraphy used in the evaluation of soft tissue sarcoma

International Nuclear Information System (INIS)

Pilloni, A.; Brooks, R.

1998-01-01

Full text: The use of thallium scintigraphy in tumour localisation is a promising diagnostic modality. Thallium has a good affinity for numerous tumour types including sarcomas. Its properties as a potassium analogue result in active uptake via the sodium- potassium ATP-ase pump enabling its use in evaluating tumour extent, viability, staging, localisation and treatment. This case illustrates the role of thallium in tumour staging. A 67-year-old woman with a fibrous histiocytoma resected from the right foot four months previously presented with pain in the ribs, lower back and feet. A bone scan was performed to assess the possibility of metastatic disease. Several abnormal foci were seen on the bone scan suggestive of metastatic disease. A thallium scan was performed to confirm the bone scan result after a subsequent CT scan showed no evidence of this extensive disease. Static images of the whole body were acquired on an Elscinct 400AG 20 minutes post i.v. injection of 3.5 mCi of thallium. Focal areas of increased thallium uptake were seen in the 11th rib posteriorly and in the left sacroiliac region corresponding with sites on the bone scan suggesting metastases. However, an extensive area of uptake was also observed in the right inguinal region which had no corresponding abnormalities in the bone study. This was thought to be tumour metastasis in an inguinal Iymph node, which was retrospectively confirmed on an earlier CT scan of the pelvis. This study demonstrates the usefulness of thallium in the detection of soft tissue tumours and metastases. Thallium also exhibits potential in the assessment of tumour extent and viability pre- and post-treatment. This potential needs to be explored further in patient management

Diagnostic Value of Myocardial Perfusion SPECT with Dipyridamole in a Female Population

International Nuclear Information System (INIS)

Perez-Iruela, Juan; Pastor, Purificacion; Lumbreras, Luis; Martin, Ana M.; Ruiz, Francisco J.; Posadas, A.; Puentes, Carmen

2009-01-01

Background: Exercise stress scintigraphy is a safe procedure widely used for the diagnosis of ischemic heart disease. Pharmacologic stress testing is an important alternative. The delayed presentation of ischemic heart disease in women, together with a lower diagnostic accuracy of exercise stress testing in this population, has generated interest in the potential benefits provided by myocardial perfusion imaging tests. Objective: To determine the diagnostic value of myocardial perfusion images with 99m Tc-tetrofosmin in a one day protocol after a pharmacologic stress with dipyridamole in a female population, and the relation with the coronary territories using coronary angiography as a reference technique. Material and Methods: In total, 149 clinical charts of women with suspected ischemic heart disease undergoing myocardial perfusion imaging tests and coronary angiography were retrospectively analyzed. Results: Sensitivity and specificity were 94% (93.47%-94.53%) and 82% (80.94%-83.06%), respectively. Values of sensitivity and specificity according to coronary territories were 71.62% (70.88%-72.36%) and 76% (75.27%-76.73%) for the left anterior descending (LAD) artery, 69.09% (68.11%-70.07%) and 76.84% (76.26%-77.42%) for the left circumflex (LCx) coronary artery, and 87.23% (86.11%-88.36%) and 74.51% (73.97%-75.05%) for the right coronary artery (RCA), respectively. Conclusion: Myocardial perfusion scintigraphy with 99m Tc-tetrofosmin and dipyridamole using a one day stress-rest protocol has high sensitivity and specificity for the diagnosis of ischemic heart disease in women. (authors) [es

Sodium bicarbonate-augmented stress thallium myocardial scintigraphy

International Nuclear Information System (INIS)

Sarin, Badal; Chugh, Pradeep Kumar; Kaushal, Dinesh; Soni, Nakse Lal; Sawroop, Kishan; Mondal, Anupam; Bhatnagar, Aseem

2004-01-01

It is well known that sodium bicarbonate in pharmacological doses induces transient alkalosis, causing intracellular transport of serum potassium. The aims of this study were (a) to investigate whether, in humans, myocardial thallium-201 uptake can be augmented by pretreatment with a single bolus of sodium bicarbonate at a pharmacological dose, (b) to verify general safety aspects of the intervention and (c) to evaluate the clinical implications of augmentation of 201 Tl uptake, if any. Routine exercise myocardial scintigraphy was performed twice in eight adult volunteers (five normal and three abnormal), once without intervention and the second time (within a week) following intravenous administration of sodium bicarbonate (88 mEq in 50 ml) as a slow bolus 1 h prior to the injection of 201 Tl. Conventional myocardial thallium study was compared with sodium bicarbonate interventional myocardial scintigraphy with respect to myocardial uptake (counts per minute per mCi injected dose), washout patterns in normal and abnormal myocardial segments, and overall clinical interpretation based on planar and single-photon emission tomographic (SPET) images. All patients remained asymptomatic after the intervention. A mean increase of 53% in myocardial uptake of thallium was noted in post-exercise acquisitions after the intervention, confirming uptake of the tracer via the potassium-hydrogen pump and its augmentation by transient alkalosis. The washout pattern remained unchanged. The visual quality of planar and SPET images improved significantly after the intervention. Out of the five abnormal myocardial segments identified in three cases, four showed significant filling-in after the intervention, causing the diagnosis to be upgraded from ''partial scar'' to ''ischaemia'', or from ''ischaemia'' to ''normal''. The overall scan impression changed in two out of three such cases. Sodium bicarbonate augmentation may have significant implications for stress-thallium scintigraphy

Brain fluorodeoxyglucose positron emission tomography (¹⁸FDG PET) in patients with acute thallium intoxication.

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Liu, C H; Lin, K J; Wang, H M; Kuo, H C; Chuang, W L; Weng, Y H; Shih, T S; Huang, C C

2013-03-01

Thallium toxicity induces cellular injury through impaired Na-K-ATPase activity. The aim of this study was to investigate functional imaging and the long-term clinical-imaging correlations of thallium toxicity. We measured thallium concentrations in blood, urine, stools, and hair of a 48-year-old woman and a 52-year-old man (patients 1 and 2) in the first 3 months after exposure to thallium containing water, and studied their neuropsychological functions. Using fluorodeoxyglucose positron emission tomography ((18)FDG PET) scans, we examined the brain involvement and correlated the image findings with the clinical presentations. On the 1st, 30th, and 61st days after exposure, the thallium concentrations in patient 1 were 2056, 311, and 7.5 μg/L in the blood, and 11400, 4570, and 36.4 μg/L in the urine. The concentrations in patient 2 were 956, 235, and 15.6 μg/L in the blood, and 11900, 2670, and 101 μg/L in the urine. On the 40th, 50th and 89th days after exposure, the thallium concentration in the stools were 21.6, 3.6, and 0.35 μg/g in patient 1, and 22.2, 3.2, and 0.37 μg/g in patient 2. Executive function, perceptual motor speed, and learning memory were initially abnormal but recovered particularly within the first year. The first (18)FDG PET studies of both patients disclosed a decreased uptake of glucose metabolism in the cingulate gyrus, bilateral frontal, and parietal lobes 2-5 months after exposure. The follow-up (18)FDG PET scan of patient 2 revealed a partial recovery. This study indicates that damage to the central nervous system after acute thallium poisoning may be reversible after a long-term follow-up. Brain (18)FDG PET demonstrated the brain involvement and was correlated with cognitive impairment.

The usefulness of planar thallium myocardial perfusion imaging in the diagnosis of coronary artery disease

International Nuclear Information System (INIS)

Johannesen, K.A.; Andersen, K.; Foelling, M.; Vik-Mo, H.

1991-01-01

Stress thallium scintigraphy was performed in 60 patients with chest pain of uncertain origin. Myocardial ischemia was identified in 91% og the 47 patients who had angiographically significant coronary artery stenosis. Sensitivity of thallium scintigraphy was highest in patients with stenosis in the left descending coronary artery (LAD); 91% of the patients had abnormal thallium as compared with 67% of the patients with normal LAD, but significant stenosis in the circumflex artery and/or the right coronary artery. Perfusion defects in the circumflex or right coronary artery regions were detected in only 50% of the patients with multiple vessel disease. The authors conclude that stress thallium scintigraphy is a useful diagnostic procedure in patients with chest pain of uncertain origin and identifies the patients to be selected for coronary artery angiography. 15 refs., 2 figs., 2 tabs

Prevention of cardiac complications in peripheral vascular surgery

International Nuclear Information System (INIS)

Cutler, B.S.

1986-01-01

The prevalence of severe coronary artery disease in peripheral vascular patients exceeds 50 per cent. Complications of coronary artery disease are the most common causes of mortality following peripheral vascular operations. To reduce the incidence of cardiac complications, it is first necessary to identify patients at risk through screening tests. Screening methods in current use include risk factor analysis, exercise testing, routine coronary angiography, and dipyridamole thallium-201 scintigraphy. The risk factor approach has the advantage of being widely applicable since it makes use of historical, physical, and electrocardiographic findings that are already familiar to surgeons and anesthesiologists. It is also inexpensive. However, it may overlook the patient who has no symptoms of coronary artery disease, possibly as a result of the sedentary lifestyle imposed by complications of peripheral vascular disease. The electrocardiographically monitored stress test will identify the asymptomatic patient with occult coronary disease and is helpful in predicting operative risk. However, a meaningful test is dependent on the patient's ability to exercise--an activity that is frequently limited by claudication, amputation, or arthritis. Exercise testing also suffers from a lack of sensitivity and specificity when compared with coronary arteriography. Routine preoperative coronary angiography overcomes the exercise limitation of treadmill testing but is not widely applicable as a screening test for reasons of cost and inherent risk. Dipyridamole thallium-201 scanning, on the other hand, is safe and of relatively low cost and does not require exercise

Neuropsychology of thallium poisoning

Science.gov (United States)

McMillan, T; Jacobson, R; Gross, M

1997-01-01

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.

 PMID:9285467

Thallium toxicity in humans.

Science.gov (United States)

Cvjetko, Petra; Cvjetko, Ivan; Pavlica, Mirjana

2010-03-01

Thallium is a naturally occurring trace element, widely distributed in the earth's crust, but at very low concentrations. It does not have a known biological use and does not appear to be an essential element for life. It has been considered one of the most toxic heavy metals.Occasionally, there are reports on thallium poisoning as results of suicide or murder attempt or accident. The main threat to humans is through occupational exposure, environmental contamination, and accumulation in food, mainly in vegetables grown on contaminated soil. Increasing use in emerging new technologies and demanding high-tech industry constantly raise concern about exposure risk to all living organisms. Thallium is considered a cumulative poison that can cause adverse health effects and degenerative changes in many organs. The effects are the most severe in the nervous system. The exact mechanism of thallium toxicity still remains unknown, although impaired glutathione metabolism, oxidative stress, and disruption of potassium-regulated homeostasis may play a role. The lack of data about mutagenic, carcinogenic, or teratogenic effects of thallium compounds in humans calls for further research.

Different thallium-201 single-photon emission tomographic patterns in benign and aggressive meningiomas

International Nuclear Information System (INIS)

Tedeschi, E.; Soricelli, A.; Brunetti, A.; Romano, M.; Bucciero, A.; Iaconetta, G.; Alfieri, A.; Postiglione, A.; Salvatore, M.

1996-01-01

To evaluate the possibility of preoperatively obtaining an index of aggressiveness for intracranial meningiomas, we prospectively studied 22 patients with computed tomographic or magnetic resonance imaging evidence of meningeal tumour, using single-photon emission tomography (SPET) of the brain and thallium-201 ( 201 Tl). On a brain-dedicated SPET scanner, a rapid acquisition protocol with early, short scans was started simultaneously with the intravenous administration of 111 MBq 201 Tl, covering the initial intratumoral distribution of the tracer. Twenty minutes post injection, a delayed SPET scan was also obtained. On the reconstructed and attenuation-corrected images we calculated the 201 Tl concentration in tumour and normal contralateral brain tissue, and compared intratumoral tracer concentration in the initial and the final part of the rapid acquisition protocol. Benign and malignant meningiomas were classified as such based on histological examination. In malignant lesions, the ratio of the 201 Tl concentration at 2-4 min post injection to that at 14-16 min was found to be significantly higher than in non-aggressive neoplasms (mean±1 SD: 1.14±0.31 and 0.56±0.13, respectively, P 201 Tl concentration values at 2-4 and at 14-16 min. Our findings suggest that the comparative assessment of intratumoral 201 Tl concentration at 2-4 and at 14-16 min post injection could provide a fast, simple method to differentiate preoperatively intracranial meningiomas with different biological behaviour. (orig.). With 3 figs., 1 tab

Computer-enhanced thallium scintigrams in asymptomatic men with abnormal exercise tests

International Nuclear Information System (INIS)

Uhl, G.S.; Kay, T.N.; Hickman, J.R. Jr.

1981-01-01

The use of treadmill testing in asymptomatic patients and those with an atypical chest pain syndrome is increasing, yet the proportion of false positive stress electrocardiograms increases as the prevalence of disease decreases. To determine the diagnostic accuracy of computer-enhanced thallium perfusion scintigraphy in this subgroup of patients, multigated thallium scans were obtained after peak exercise and 3 or 4 hours after exercise and the raw images enhanced by a computer before interpretations were made. The patient group consisted of 191 asymptomatic U.S. Air force aircrewmen who had an abnormal exercise electrocardiogram. Of these, 135 had normal coronary angiographic findings, 15 had subcritical coronary stenosis (less than 50 percent diameter narrowing) and 41 had significant coronary artery disease. Use of computer enhancement resulted in only four false positive and two false negative scintigrams. The small subgroup with subcritical coronary disease had equivocal results on thallium scintigraphy, 10 men having abnormal scans and 5 showing no defects. The clinical significance of such subcritical disease in unclear, but it can be detected with thallium scintigraphy. Thallium scintigrams that have been enhanced by readily available computer techniques are an accurate diagnostic tool even in asymptomatic patients with an easily interpretable abnormal maximal stress electrocardiogram. Thallium scans can be effectively used in counseling asymptomatic patients on the likelihood of their having coronary artery disease

In situ deposition of thallium-containing oxides

International Nuclear Information System (INIS)

Myers, K.E.

1996-01-01

The number and variety of thallium based materials that can be made by in situ methods have grown consistently since the first report of successful thallium cuprate deposition by Face and Nestlerode in 1992. Processes for the deposition of superconductors, normal metals, and insulators have been developed. Most work to date has been done on the Tl-1212 phases, TlBa 2 CaCu 2 O 7 and (Tl,Pb)Sr 2 CaCu 2 O 7 . Recently however, the in situ thallium technique has been extended to other materials. For example, epitaxial thin films of thallium tantalate, an insulator of the pyrochlore structure and a potential buffer layer for thallium cuprate films, have been grown. Multilayers, important in the fabrication of Josephson junctions, have been demonstrated with the thallium lead cuprates. This paper reviews progress in the area of in situ thallium deposition technology which will make more complex thallium cuprate multilayer structures and devices possible

Prognostic importance of thallium uptake by the lungs during exercise in coronary artery disease

International Nuclear Information System (INIS)

Gill, J.B.; Ruddy, T.D.; Newell, J.B.; Finkelstein, D.M.; Strauss, H.W.; Boucher, C.A.

1987-01-01

We studied the value of thallium imaging as compared with clinical and exercise-test variables in predicting cardiac events occurring over five years in 525 consecutive patients referred for thallium-exercise testing in 1979. Follow-up was obtained on 467 patients (89 percent). There were 105 cardiac events--25 cardiac deaths, 33 myocardial infarctions, and 47 coronary bypass procedures. A Cox survival analysis identified increased thallium uptake by the lungs, a marker of left ventricular dysfunction during exercise, as the best predictor of a cardiac event (relative risk ratio = 3.5; 95 percent confidence interval, 2.2 to 5.4). The next most powerful predictors were a history of typical angina, a previous myocardial infarction, and ST-segment depression during exercise (relative risk ratios = 2.1, 1.8, and 1.7, respectively). No combination of variables made up for the loss in prognostic power when the variable of increased thallium uptake by the lungs was removed from the model. Cardiac events occurred over five years in 10 (5 percent) of 192 patients with a normal thallium scan, 41 (25 percent) of 163 patients with an abnormal thallium scan but normal thallium activity in the lungs, and 54 (67 percent) of 81 patients with increased thallium uptake by the lungs (P less than 0.0001). We conclude that increased uptake of thallium by the lungs during exercise predicts a high risk of subsequent cardiac events

Technetium-99m tetrofosmin imaging in thyroid diseases: comparison with Tc-99m-pertechnetate, thallium-201 and Tc-99m-methoxyisobutylisonitrile scans

International Nuclear Information System (INIS)

Klain, M.; Cuocolo, A.; Marzano, L.; Lombardi, G.; Salvatore, M.; Univ. di Napoli

1996-01-01

In this study, tetrofosmin whole-body scintigraphy was performed in 35 patients with evidence of thyroid diseases. All patients underwent laboratory evaluation of thyroid function as well as 99m Tc pertechnetate scan, thallium-201 99m Tc-methoxyisobutylisonitrile (MIBI) whole-body studies. Thyroid images were semi-quantitatively analysed by a 4-point score: 0=no significant uptake; 1=uptake increased but inferior to normal thyroid tissue; 2=uptake equal to normal thyroid tissue; 3=uptake superior to normal thyroid tissue. A total of 41 thyroid nodules were detected, of which 15 were goitre nodules, 13 adenomas and 13 malignant lesions. In goitre nodules, concordant results of tetrofosmin and pertechnetate uptake (score 1 or 0) were observed in the majority of lesions (87%). In function adenomas both tetrofosmin uptake and pertechnetate uptake were score 3. In non-function adenomas tetrofosmin uptake was score 3, while pertechnetate uptake was score 0. In six malignant lesions, tetrofosmin uptake was score 3, while pertechnetate uptake was score 0; in the other seven lesions, where a prevalence of goitre abnormalities was observed, results of tetrofosmin and pertechnetate uptake were similar (score 0 or 1). In (70%) patients with malignant nodules, whole-body tetrofosmin images showed increased abnormal uptake in a total of 28 extra-thyroid tumour sites, as subsequently confirmed by other techniques. When tetrofosmin images were compared to 201 Tl and 99m Tc-MIBI scans, concordant results were observed in all cases. In conclusion, tetrofosmin imaging may be particularly useful to characterize and stage patients with malignant thyroid nodules; it shows similar results to thallium but provides better image quality. Comparable findings were observed between tetrofosmin and MIBI studies. Thus, tetrofosmin may be an alternative to thallium and MIBI in the aforementioned patients. (orig.). With 4 figs., 3 tabs

Thallium-201 for myocardial imaging: appearance of the normal heart

International Nuclear Information System (INIS)

Cook, D.J.; Bailey, I.; Strauss, H.W.; Rouleau, J.; Wagner, H.N. Jr.; Pitt, B.

1976-01-01

Thallium-201 myocardial perfusion images were obtained from 13 healthy adults after tracer administration both at rest and at maximal stress. On the rest-injected scan, tracer was seen in left ventricular myocardium, liver, and spleen. In two subjects with resting tachycardia, the right ventricular myocardium was slightly visualized after tracer injection at rest. When tracer was administered at stress, the left ventricular activity was more nearly homogeneous and the left ventricle was better defined on the scan. The left-ventricle-to-lung-background activity ratio increased from 2.4 at rest to 3.4 at stress. The right ventricular myocardium was seen on the stress-injected scan. Phantom studies, performed to define the optimum position for visualization of lesions, showed that small lesions were best defined when seen either en face or in tangent. Scans should be performed at stress whenever possible and multiple views are essential

Brain SPECT using dipyridamole for evaluation of vascular reserve

International Nuclear Information System (INIS)

Kim, Su Zy; Park, Chan Hee; Yoon, Soo Hwan; Pai, Moon Sun; Yoon, Suk Nam; Cho, Kyung Kee

1997-01-01

Baseline and stress brain SPECT studies using CO 2 inhalation, acetazolamide (Diamox R ) and adenosine administrations have been used in the evaluation of cerebral vascular reserve. Recently dipyridamole (Persantine R ) which is one of the pharmacologic myocardial perfusion SPECT agents as a potent vasodilator is suggested as another cerebral vasodilator. IV Diamox R is not available in Korea. Therefore, the purpose of our study was to evaluate dipyridamole in stress brain SPECT in patients with Moya Moya disease. Eight patients with angiographically proven Moya Moya disease were studied. Their ages ranged from 7 to 62 year old. There were 4 males and 4 females. Each patient had a baseline and persantine brain SPECT studies with 1 to 3 days' interval. Dipyridamole was given intravenously at a dose of 0.56 mg/kg over 4 minutes while watching vital signs such as blood pressure, heart rate, and electrocardiogram. Three minutes after the completion of the infusion, 99mTc-ECD (0.2 mCi/Ib body weight) was injected. Brain SPECT was performed 30 minutes later using a tripple head gamma camera equipped with LEHR collimators. A total of 128 projections with an acquisition time of 30 second per projection was obtained and reconstructed by filtered back projections without attenuation correction. The difference between the baseline and persantine studies was analysed by visual and semiquantitavely. During the infusion of persantine, heart rate, blood pressure and side effects such as headache, chest discomfort were similar to the persantine myocardial SPECT studies. Five of eight patients showed a significant decrease in rCBF on persantine brain SPECT in comparison to the baseline study. The remaining three revealed no significant change in rCBF. Our study suggests that the dipyridamole stress brain SPECT is feasible and useful in assessing cerebral blood flow reserve. However we need to evaluate more number of patients in the future

Thallium intoxication. Case Report.

Science.gov (United States)

Sojáková, Michaela; Žigrai, Miroslav; Karaman, Andrej; Plačková, Silvia; Klepancová, Petra; Hrušovský, Štefan

2015-01-01

We report a rare case of serious voluntary intoxication by laboratory thallium monobromate combined with alcohol intake by a 24-years old man. The diagnosis of thallium intoxication was based on history, nonspecific but typical clinical symptoms including gastrointestinal complaints, painful polyneuropathy, alopecia, and confirmed by the finding of increased thallium concentration in the urine. The treatment, performed at the due time, consisted of decontamination of the stomach by irrigation, administration of active charcoal and Prussian blue, correction of water and mineral dysbalance, symptomatic treatment, and led to complete recovery.

Value of 201-thallium serial myocardial imaging in coronary heart disease

International Nuclear Information System (INIS)

Sauer, E.; Sebening, H.; Dressler, J.; Lutilsky, L.; Ulm, K.; Hoer, G.; Papst, H.W.; Bloemer, H.; Technische Univ. Muenchen; Technische Univ. Muenchen

1979-01-01

There has been clinical evidence that a perfusion defect on a stress image fills overtime. The diagnostic value of initial and 120 min post exercise redistribution thallium-201 myocardial images (RMI) was determined in 120 pts, with suspected coronary heart disease (CAD), all of whom had coronary arteriography. Significant (>= 75%) lesions were present in 88 pts. 30 pts. without CAD showed a normal tracer uptake immediately after exercise. Scintigrams taken 120 min after exercise revealed a decrease of 201-Tl concentration in every area of the myocardium. 80 pts. with CAD showed an area of decreased tracer uptake in the inital scans. 120 min RMI in 51 pts. revealed a significant increase (p > 0.01) of countrate time ratio in previous underperfused areas. In 37 pts. persistent defects were present, in every case the defect correlated with the site of a myocardial infarction as determined by the finding of an akinetic area in the left ventricular angiogram. Thus RMI following a single dose of 201 Tl can differentiate between scar- and exercise-induced transient ischemia. (orig.) 891 AJ/orig. 892 MB [de

Contribution to the study of thallium 201 myocardium scintigraphy

International Nuclear Information System (INIS)

Annweiler, Marc.

1976-01-01

In this work a new isotope was tested in the field of myocardium scintigraphy: thallium 201. The different radioisotopes used so far in myocardium scintigraphy are reviewed to begin with. The main biological and physical characteristics of thallium and the scintillation camera used for this work are described next. In our opinion thallium 201 owing to its biological behavior similar to that of potassium and to its physical characteristics, appears as one of the better -if not the best- known tracer suitable for use in myocardium scintigraphy. Its properties are suited to the use of a scintillation camera, which considerably shortens the examination time and thus allows an isotopic exploration of the myocardium from several incidences. The only disadvantage of this cyclotron-produced isotope seems to be its high price which will probably limit its use on a large scale. Fifty thallium 201 myocardium scintigraphs were practised on forty-eight coronary thrombosis patients. From this was established a precise topographic correlation between the electrocardiographic diagnosis and the scintigraph. The two corresponded in 47 cases out of 50. The few disagreements between ECG and scintigraphic results seem to be due either to poor-quality images or to an overall myocardium hypofixation connected with a very extensive necrosis. This means that thallium 201 myocardium scintigraphy is a reliable method of examination in the great majority of cases, giving a direct picture of the heart muscle and its necrotic lesions [fr

Radionuclide-determined changes in pulmonary blood volume and thallium lung uptake in patients with coronary artery disease

International Nuclear Information System (INIS)

Wilson, R.A.; Okada, R.D.; Boucher, C.A.; Strauss, H.W.; Pohost, G.M.

1983-01-01

Exercise-induced increases in radionuclide-determined pulmonary blood volume (PBV) and thallium lung uptake have been described in patients with coronary artery disease (CAD) and have been shown to correlate with transient exercise-induced left ventricular dysfunction. To compare these 2 techniques in the same patients, 74 patients (59 with and 15 without significant CAD) underwent supine bicycle exercise twice on the same day--first for thallium myocardial and lung imaging and then for technetium-99m gated blood pool imaging for the PBV ratio determination. Thallium activity of lung and myocardium was determined to calculate thallium lung/heart ratio. Relative changes in PBV from rest to exercise were expressed as a ratio of pulmonary counts (exercise/rest). Previously reported normal ranges for thallium lung/heart ratio and PBV ratio were used. The PBV ratio and thallium lung/heart ratio were abnormal in 71 and 36%, respectively, of patients with CAD (p less than 0.01). Both ratios were normal in all patients without CAD. Although the resting ejection fractions did not differ significantly in patients with normal versus those with abnormal PBV ratios or thallium lung/heart ratios, abnormal PBV ratios and thallium lung/heart ratios were associated with an exercise-induced decrease in ejection fraction. Propranolol use was significantly higher in patients with abnormal than in those with normal thallium lung/heart ratios (p less than 0.01). No significant difference in propranolol use was present in patients with abnormal or normal PBV ratios. In conclusion: (1) the prevalence of an abnormal thallium lung/heart ratio is less than that of the PBV ratio in patients with CAD; (2) both tests are normal in normal control subjects; (3) propranolol does not cause abnormal results in normal control subjects; however, propranolol may influence lung thallium uptake in patients with CAD; and (4) when both tests are abnormal, there is a high likelihood of multivessel disease

Studies about the stress transaxial myocardium tomography with thallium -201

International Nuclear Information System (INIS)

Rocha Pantoja, M. da.

1987-01-01

Since the time of earliest applications of SPECT technology to Thallium-201 myocardial perfusion imaging, there has been no agreement as to what constitutes the best procedures to follow in order to achieve the theoretical advantages of SPECT to diagnose coronary artery disease. The purpose of these studies are to show the results of experimental and clinical investigations, that, have helped to resolve most of some controversies. Myocardial perfusion SPECT with Thallium-201 is clinically useful procedure that is readily applicable for routine clinical application provided correct techniques are utilized. (author)

Reducing radiation dose without compromising image quality in preoperative perforator flap imaging with CTA using ASIR technology.

Science.gov (United States)

Niumsawatt, Vachara; Debrotwir, Andrew N; Rozen, Warren Matthew

2014-01-01

Computed tomographic angiography (CTA) has become a mainstay in preoperative perforator flap planning in the modern era of reconstructive surgery. However, the increased use of CTA does raise the concern of radiation exposure to patients. Several techniques have been developed to decrease radiation dosage without compromising image quality, with varying results. The most recent advance is in the improvement of image reconstruction using an adaptive statistical iterative reconstruction (ASIR) algorithm. We sought to evaluate the image quality of ASIR in preoperative deep inferior epigastric perforator (DIEP) flap surgery, through a direct comparison with conventional filtered back projection (FBP) images. A prospective review of 60 consecutive ASIR and 60 consecutive FBP CTA images using similar protocol (except for radiation dosage) was undertaken, analyzed by 2 independent reviewers. In both groups, we were able to accurately identify axial arteries and their perforators. Subjective analysis of image quality demonstrated no statistically significant difference between techniques. ASIR can thus be used for preoperative imaging with similar image quality to FBP, but with a 60% reduction in radiation delivery to patients.

Myocardial scintigraphy with thallium-201

International Nuclear Information System (INIS)

Schwaiger, M.; Silber, S.; Klein, U.; Rudolph, W.

1980-01-01

Thallium-201 myocardial scintigraphy is an important non-invasive method for assessment of coronary artery disease. Other applications of the method such as delineation of the right ventricular free wall in right ventricular overload, or the detection of hypertrophic cardiomyopathies or myocardial infiltrations are of subordinate importance. In heart disease such as congestive cardiomyopathy and mitral valve prolapse thallium-201 uptake defects have been described, the clinical implications of these findings, however, cannot be adequately interpreted at this time. Myocardial uptake of thallium-201 is an active process, dependent on and proportional to perfusion. Differentiation between myocardial ischemia and myocardial scar is based on the presence or absence of thallium-201 'redistribution'. That is, in the presence of acute reversible ischemia there is increased thallium-201 uptake in the post-ischemic phase in previously hypoperfused myocardium and, subsequently, equilibrium of the initially registered activity differences. 'Redistribution' has also been described in the resting scintigram of patients with severe coronary artery disease and chronic hypoperfusion. (orig.) [de

Quantitative thallium-201 myocardial exercise scintigraphy in normal subjects and patients with normal coronary arteries

International Nuclear Information System (INIS)

Niemeyer, M.G.; St. Antonius Hospital Nieuwegein; Laarman, G.J.; Lelbach, S.; Cramer, M.J.; Ascoop, C.A.P.L.; Verzijlbergen, J.F.; Wall, E.E. van der; Zwinderman, A.H.; Pauwels, E.K.J.

1990-01-01

Quantitative thallium-201 myocardial exercise scintigraphy was tested in two patient populations representing alternative standards for cardiac normality: group I comprised 18 male uncatherized patients with a low likelihood of coronary artery disease (CAD); group II contained 41 patients with normal coronary arteriograms. Group I patients were younger, they achieved a higher rate-pressure product than group II patients; all had normal findings by phisical examination and electrocardiography at rest and exercise. Group II patients comprised 21 females, 11 patients showed abnormal electrocardiography at rest, and five patients showed ischemic ST depression during exercise. Twelve patients had sign of minimal CAD. Twelve patients revealed abnormal visual and quantitative thallium findings, three of these patients had minimal CAD. Profiles of uptake and washout of thallium-201 were derived from both patient groups, and compared with normal limits developed by Maddahi et al. Furthermore, low likelihood and angiographically normal patients may differ substantially, and both sets of normal patients should be considered when establishing criteria of abnormality in exercise thallium imaging. When commercial software containing normal limits for quantitative analysis of exercise thallium-201 imaging is used in clinical practice, it is mandatory to compare these with normal limits of uptake and washout of thallium-201, derived from the less heterogeneous group of low-likelihood subjects, which should be used in selecting a normal population to define normality. (author). 37 refs.; 3 figs; 1 tab

Superconducting thallium cuprates obtained by substitution of copper for thallium in the double-thallium layer cuprate (Tl2212)

International Nuclear Information System (INIS)

Gopalakrishnan, J.; Shivakumara, C.; Manivannan, V.

1994-01-01

A new series of superconducting thallium cuprates of nominal composition, (Tl 2-x Cu x )Ba 2 CaCu 2 O 8 (0 c s in the range 110--99K. The phases are metastable, decomposing at higher temperatures (∼1,150K) to a mixture of thallium cuprates, CuO and BaCuO 2 . Significantly, x=1 member decomposes at 1,150K to mixture of Tl2223, CuO and BaCuO 2 . Chemical titrations involving oxidation of bromide ions reveals that the copper substituting for thallium in (Tl 2-x Cu x )Ba 2 CaCu 2 O 8 most likely occurs in the III oxidation state for x≤0.25 and in a mixed state (II,III) state for x>0.25

A model to predict multivessel coronary artery disease from the exercise thallium-201 stress test

International Nuclear Information System (INIS)

Pollock, S.G.; Abbott, R.D.; Boucher, C.A.; Watson, D.D.; Kaul, S.

1991-01-01

The aim of this study was to (1) determine whether nonimaging variables add to the diagnostic information available from exercise thallium-201 images for the detection of multivessel coronary artery disease; and (2) to develop a model based on the exercise thallium-201 stress test to predict the presence of multivessel disease. The study populations included 383 patients referred to the University of Virginia and 325 patients referred to the Massachusetts General Hospital for evaluation of chest pain. All patients underwent both cardiac catheterization and exercise thallium-201 stress testing between 1978 and 1981. In the University of Virginia cohort, at each level of thallium-201 abnormality (no defects, one defect, more than one defect), ST depression and patient age added significantly in the detection of multivessel disease. Logistic regression analysis using data from these patients identified three independent predictors of multivessel disease: initial thallium-201 defects, ST depression, and age. A model was developed to predict multivessel disease based on these variables. As might be expected, the risk of multivessel disease predicted by the model was similar to that actually observed in the University of Virginia population. More importantly, however, the model was accurate in predicting the occurrence of multivessel disease in the unrelated population studied at the Massachusetts General Hospital. It is, therefore, concluded that (1) nonimaging variables (age and exercise-induced ST depression) add independent information to thallium-201 imaging data in the detection of multivessel disease; and (2) a model has been developed based on the exercise thallium-201 stress test that can accurately predict the probability of multivessel disease in other populations

Dipyridamole reduces penile apoptosis in a rat model of post-prostatectomy erectile dysfunction

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Omer Kutlu

Full Text Available ABSTRACT Purpose: Despite the nerve-sparing technique, many patients suffer from erectile dysfunction after radical prostatectomy (RP due to cavernous nerve injury. The aim of this study was to evaluate dipyridamole as a potential treatment agent of post-radical prostatectomy erectile dysfunction. Material and methods: A total of 18 male Sprague-Dawley rats were randomized into three experimental Groups (SHAM+DMSO, BCNI+DMSO and BCNI+DIP. An animal model of bilateral cavernous nerve crush injury (BCNI was established to mimic the partial nerve damage during nerve-sparing RP. After creating of BCNI, dimethyl sulphoxide (DMSO was administered transperitoneally as a vehicle to SHAM+DMSO and BCNI+DMSO Groups. BCNI+DIP Group received dipyiridamole (10mg/kg/day as a solution in DMSO for 15 days. Afterwards, rats were evaluated for in vivo erectile response to cavernous nerve stimulation. Penile tissues were also analyzed biochemically for transforming growth factor-β1 (TGF-β1 level. Penile corporal apoptosis was determined by TUNEL method. Results: Erectile response was decreased in rats with BCNI and there was no significant improvement with dipyridamole treatment. TGF-β1 levels were increased in rats with BCNI and decreased with dipyridamole treatment. Dipyridamole led to reduced penile apoptosis in rats with BCNI and there was no significant difference when compared to sham operated rats. Conclusions: Although fifteen-day dipyridamole treatment has failed to improve erectile function in rats with BCNI, the decline in both TGF-β1 levels and apoptotic indices with treatment may be helpful in protecting penile morphology after cavernous nerve injury.

Thallium-201 myocardial imaging for evaluation of pulmonary hypertension

International Nuclear Information System (INIS)

Ikuno, Yoshiyasu

1979-01-01

Thallium-201 ( 201 Tl) myocardial scintigraphy (TMS) was performed in 54 patients. The images were analysed semi-quantitatively by measuring the extent of radioisotope concentration in the right ventricular free wall and the size of the right ventricular cavity. The extent of radioisotope concentration (four degrees) was expressed as the right ventricular activity score (RVAS) and the size of the right ventricular cavity (three degrees) was expressed as the right ventricular cavity score (RVCS). The scores were added for a right ventricular total score (RVTS). To establish criteria for the diagnosis of pulmonary hypertension (PH) by means of TMS, these scores were compared with the values of pulmonary arterial mean pressure (PAMP). The criteria were evaluated by comparing them with conventional criteria for electrocardiographic diagnosis of right ventricular hypertrophy. Patients with a 2-point RVAS had a significantly higher PAMP than those with a 0 or 1-point RVAS (p 201 Tl myocardial scintigrams is a useful non-invasive method for evaluating PH and its severity. (J.P.N.)

Withholding or Continuing Beta-Blocker Treatment Before Dipyridamole Myocardial Perfusion Imaging for the Diagnosis of Coronary Artery Disease? a Randomized Clinical Trial

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Babak Fallahi

2013-01-01

Full Text Available Although it has been shown that acute beta-blocker administration may reduce the presence or severity of myocardial perfusion defects with dipyridamole stress, little information is available about the potential effect of chronic beta-blocker treatment on the sensitivity of dipyridamole myocardial perfusion imaging (DMPI.Methods As a randomized clinical trial, one hundred twenty patients (103 male and 17 female with angiographically confirmed CAD who were on long-term beta blocker therapy ([greater than or equal to]3 months enrolled in a randomized clinical trial study. The patients were allocated into two groups: Group A (n=60 in whom the beta-blocker agent was discontinued for 72h before DMPI and Group B (n=60 without discontinuation of beta-blockers prior to DMPI.ResultsNo significant difference was noted between the groups concerning age, sex, type of the injected radiotracer and number of involved coronary vessels. The mean rank of total perfusion scores for whole myocardium (irrespective of reversibility or irreversibility in group B was not significantly different from that of group A, (65.75 vs. 55.25, P=0.096. Regarding the only irreversible perfusion defects, the mean rank of perfusion score in group B was higher than that of group A for whole myocardium (72 vs. 49, P=0.0001; however, no difference was noted between two groups for only reversible perfusion defects (61.0 vs. 60.0, P=0.898. The overall sensitivity of DMPI for the diagnosis of CAD in group A (91.7% was not statistically different from group B (90%.ConclusionBeta-blocker withholding before DMPI did not generally affect the sensitivity of the test for the diagnostic purposes in our study. Thus, beta-blocker withdrawal for just the purpose of diagnostic imaging is not mandatory particularly when medication discontinuation may cause the patients to face increased risk of heart events.

Sensitivity of thallium scintigraphy in the detection of individual coronary artery disease

International Nuclear Information System (INIS)

Khan, A.; Rehman, A.; Wiqar, M.A.; Khan, Z.A.; Ahmad, S.A.

1988-01-01

In this study we randomly selected 45 patients whose coronary angiograms were abnormals i.e. showing triple, double and single vessel disease. Out of 80 patients who had undergone stress thallium imaging and coronary angiography during the one year. Majority of these patients were males and their ages ranged between 34-54 years. Fifteen patients had suffered inferior myocardial infraction and 5 had sustained anterior myocardial infraction in the fast. We analysed their coronary angiograms and compared them with the scintigraphic findings. It is concluded that although thallium scanning has high sensitivity for detection of coronary artery disease in general, it has only moderate sensitivity for detection of stenosis in individual coronary arteries. In this study thallium scan identified 75% of RCA lesions, 66% of LAD lesions and 38% circumflex lesions. Thallium scan sometimes fails to identify the less serve lesions in presence of more severe coronary lesions in the some patients. The sensitivity is much higher in single vessel coronary artery disease. (author)

Study on the treatment of acute thallium poisoning.

Science.gov (United States)

Zhang, Hong-Tao; Qiao, Bao-Ping; Liu, Bao-Ping; Zhao, Xian-Guo

2014-05-01

Acute thallium poisoning rarely occurs but is a serious and even fatal medical condition. Currently, patients with acute thallium poisoning are usually treated with Prussian blue and blood purification therapy. However, there are few studies about these treatments for acute thallium poisoning. Nine patients with acute thallium poisoning from 1 family were treated successfully with Prussian blue and different types of blood purification therapies and analyzed. Prussian blue combined with sequential hemodialysis, hemoperfusion and/or continuous veno-venous hemofiltration were effective for the treatment of patients with acute thallium poisoning, even after delayed diagnosis. Blood purification therapies help in the clearance of thallium in those with acute thallium poisoning. Prussian blue treatment may do the benefit during this process.

Computer-enhanced thallium scintigrams in asymptomatic men with abnormal exercise tests

International Nuclear Information System (INIS)

Uhl, G.S.; Kay, T.N.; Hickman, J.R. Jr.

1981-01-01

The usefulness of computer-enhanced thallium-201 myocardial perfusion scintigraphy in excluding the diagnosis of coronary artery disease in asymptomatic patients showing abnormal exercise electrocardiograms is evaluated. Multigated thallium scans were obtained immediately following and 3 or 4 hours after maximal exercise testing in 191 consecutive asymptomatic Air Force aircrew members who had shown abnormal exercise electrocardiograms and who were due to undergo coronary angiography. Computer enhancement of the raw images is found to lead to four false positive and two false negative scintigrams as revealed by angiographic results, while the group of 15 with subcritical coronary disease exhibited equivocal results. Results reveal that enhanced thallium scintigrams are an accurate diagnostics tool in detecting myocardial ischemia in asymptomatic patients and may be used in counseling asymptomatic patients on their likelihood of having coronary artery disease

Sodium bicarbonate-augmented stress thallium myocardial scintigraphy

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Sarin, Badal; Chugh, Pradeep Kumar; Kaushal, Dinesh; Soni, Nakse Lal; Sawroop, Kishan; Mondal, Anupam; Bhatnagar, Aseem [Department of Nuclear Medicine, Institute of Nuclear Medicine and Allied Sciences, Brig. S. K. Mazumdar Road, 110054, Delhi (India)

2004-04-01

It is well known that sodium bicarbonate in pharmacological doses induces transient alkalosis, causing intracellular transport of serum potassium. The aims of this study were (a) to investigate whether, in humans, myocardial thallium-201 uptake can be augmented by pretreatment with a single bolus of sodium bicarbonate at a pharmacological dose, (b) to verify general safety aspects of the intervention and (c) to evaluate the clinical implications of augmentation of {sup 201}Tl uptake, if any. Routine exercise myocardial scintigraphy was performed twice in eight adult volunteers (five normal and three abnormal), once without intervention and the second time (within a week) following intravenous administration of sodium bicarbonate (88 mEq in 50 ml) as a slow bolus 1 h prior to the injection of {sup 201}Tl. Conventional myocardial thallium study was compared with sodium bicarbonate interventional myocardial scintigraphy with respect to myocardial uptake (counts per minute per mCi injected dose), washout patterns in normal and abnormal myocardial segments, and overall clinical interpretation based on planar and single-photon emission tomographic (SPET) images. All patients remained asymptomatic after the intervention. A mean increase of 53% in myocardial uptake of thallium was noted in post-exercise acquisitions after the intervention, confirming uptake of the tracer via the potassium-hydrogen pump and its augmentation by transient alkalosis. The washout pattern remained unchanged. The visual quality of planar and SPET images improved significantly after the intervention. Out of the five abnormal myocardial segments identified in three cases, four showed significant filling-in after the intervention, causing the diagnosis to be upgraded from ''partial scar'' to ''ischaemia'', or from ''ischaemia'' to ''normal''. The overall scan impression changed in two out of three such cases. Sodium

Myocardial imaging by direct injection of thallium-201 into coronary artery

International Nuclear Information System (INIS)

Sugihara, Hiroki; Inagaki, Suetsugu; Kubota, Yasushi

1988-01-01

Myocardial perfusion images were evaluated by direct injection of Thallium (Tl)-201 into coronary artery. Approximately 0.5 - 1 mCi of Tl-201 were instilled into the right coronary artery and/or the left coronary artery after coronary arteriography. Three images were obtained in the anterior, left anterior oblique and left lateral projections. Myocardial perfusion images of single photon emission computed tomography were also acquired in some patients. An image of supreme quality could be obtained in spite of small dose of Tl-201 since there was a lack of interference from background activity. Myocardial perfusion images corresponded to areas which were supplied by left or right coronary artery respectively. And the regional myocardial blood flow distribution of a coronary artery bypass graft could be revealed by instilling Tl-201 into the graft. Further, contribution of collateral channels to myocardial perfusion was showed. Not only left ventricle but also right ventricle was clearly visualized by injection of Tl-201 into right coronary artery. But in a case with arrhythmogenic right ventricular dysplasia, there was an area of decreased tracer uptake in the apex of the right ventricle which was identified as the site of dysplasia by electrophysiologic study. We conclude that direct injection of Tl-201 into coronary artery is an useful method to clarify the correlation between coronary anatomical findings and coronary perfusion and contribution of collaterals to myocardial perfusion, and also to detect the right ventricular myopathic site. (author)

Pharmacokinetic and dosimetric characteristics of some thallium isotopes

International Nuclear Information System (INIS)

Tultaev, A.V.; Tarasenko, Yu.I.; Popov, V.I.; Korsunskij, V.N.

1989-01-01

Pharmacokinetics is studied, radiation doses to patients when using domestic thallium-201 chloride in diagnosis of the heart ischemic disease is estimated; contribution into the total dose of thallium-201 (1.5 %), thallium-201 (0.2 %) and lead-201 + lead-203 (0.05 %) radionuclide impurities is also determined. Internal doses were estimated for a heterogeneous phantom of a standard man; the calculations were carried out using a computer. Scanning of patients which were treated with radiopharmaceuticals to be diagnosed was carried out using a whole body counter and gamma-chamber. Large intestine, kidneys and thyroid are the critical organs when using thallium-201 chloride. The highest contribution into the dose to organs and the whole body from thallium-200 and thallium-202 impurities being contained in thallium-201, doesn't exceed 8.6 %. The contribution into the dose from lead-201 and lead-203 may be ignored. Doses from thallium-199 preparation per activity unit are ∼10 times less in comparison with those from thallium-201. 19 refs.; 1 fig.; 5 tabs

Nuclear Scan Strategy and Outcomes in Chest Pain Patients Value of Stress Testing with Dipyridamole or Adenosine

International Nuclear Information System (INIS)

Conti, Alberto; Mariannini, Yuri; Canuti, Erica; Petrova, Tetyana; Innocenti, Francesca; Zanobetti, Maurizio; Gallini, Chiara; Costanzo, Egidio

2014-01-01

To update the prognostic value of scan strategy with pharmacological stress agent in chest pain (CP) patients presenting with normal electrocardiography (ECG) and troponin. Two consecutive nonrandomized series of patients with CP and negative first-line workup inclusive of serial ECG, serial troponin, and echocardiography underwent myocardial perfusion imaging single photon emission computed tomography (SPECT) in the emergency department. Of 170 patients enrolled, 52 patients underwent dipyridamole-SPECT and 118 adenosine-SPECT. Patients with perfusion defects underwent angiography, whereas the remaining patients were discharged and followed-up. Primary endpoint was the composite of nonfatal myocardial infarction, unstable angina, revascularization, and cardiovascular death at follow-up or the presence of coronary stenosis > 50% at angiography. At multivariate analysis, the presence of perfusion defects or hypertension was independent predictor of the primary endpoint. Sensitivity and negative predictive value were higher in patients subjected to adenosine-SPECT (95% and 99%, respectively) versus dipyridamole-SPECT (56% and 89%; yield 70% and 11%, respectively; P < 0.03). Of note, sensitivity, negative, and positive predictive values were high in patients with hypertension (100%, 93%, and 60%, respectively) or nonischemic echocardiography alterations (100%, 100%, and 100%, respectively). In CP patients, presenting with normal ECG and troponin, adenosine-SPECT adds incremental prognostic values to dipyridamole-SPECT. Costly scan strategy is more appropriate and avoids unnecessary angiograms in patients with hypertension or nonischemic echocardiography alterations

Nuclear cardiology. I - Radionuclide angiographic assessment of left ventricular contraction: uses, limitations and future directions. II - The role of myocardial perfusion imaging using thallium-201 in diagnosis of coronary heart disease

International Nuclear Information System (INIS)

Bodenheimer, M.M.; Banka, V.S.; Helfant, R.H.; Pennsylvania, University, Philadelphia, PA)

1980-01-01

The current status of radionuclide angiography is reviewed. First pass and gated equilibrium methods for determining left ventricular contraction are compared. Some clinical applications of radionuclide angiography are then examined, including the detection of discrete versus diffuse asynergy and the assessment of myocardial infarction. The second part of this work reviews the uses and limitations of thallium-201 perfusion imaging in the diagnosis of the acute and chronic manifestations of coronary heart disease. Theoretical and technical considerations of thallium-201 imaging are reviewed along with the clinical implications of the technique

Value of exercise thallium-201 imaging in patients with diagnostic and nondiagnostic exercise electrocardiograms

International Nuclear Information System (INIS)

Iskandrian, A.S.; Segal, B.L.

1981-01-01

The role of exercise imaging with thallium-201 in the evaluation of patients suspected of having coronary artery disease was studied in 194 patients undergoing diagnostic coronary arteriography. Ninety-eight patients had 70 percent or more narrowing of one or more coronary vessels and 96 patients had either no or insignificant coronary artery disease. One hundren twenty-three of the 194 patients had conclusive treadmill exercise electrocardiograms (either positive or negative), and 71 had inconclusive exercise electrocardiograms. The specificity of exercise imaging (97 percent) was higher than that of exercise electrocardiograms (86 percent, p less than 0.02). The specificity of both tests combined was not significantly different from that of exercise electrocardiograms alone. The sensitivity (79 percent) and specificity (95 percent) of exercise imaging were not significantly different in patients with inconclusive exercise electrocardiograms when compared with those in patients whose exercise electrocardiograms were conclusive. These data indicate that exercise imaging is sensitive and specific in diagnosing coronary artery disease in the presence of diagnostic as well as nondiagnostic exercise electrocardiograms and that propranolol therapy does not affect the results

Sorption technique of separation of thallium-201 from proton-irradiated thallium

International Nuclear Information System (INIS)

Deptula, Cz.; Zajtseva, N.G.; Mikolaevskij, S.; Khalkin, V.A.

1989-01-01

A sorption technique is developed for radiochemical separation of thallium-201 from proton-irradiated targets of metallic thallium. The technique consists in separation of 201 Pb and 201 Tl in the column with ammonium 12-molybdophosphate fixed in the matrix of porous Teflon (AMP-sorbent). The chemical yield of radiothallium is 98 %, the duration of chemical procedures is 2.5-3 hours. 21 refs.; 1 fig.; 1 tab

Study and development recuperation of Thallium-203 from bombarded targets of this metal in production of Thallium-201 via addition of Thallium-201 radioisotope as a tracer

International Nuclear Information System (INIS)

Shirazi, B.

2006-01-01

Thallium-203 is the main material for 201 TlCl 3 radiopharmaceutical. It is very important to recover the remaining enriched Thallium-203 in every stage of the process to be reused in the production loop. In this research, the recuperation of Thallium-203 was studied with Dowex 50 WΧ8 ion exchange resin and Thallium-201 as a tracer. The results based on filling of ( 1 8 X 1.5) cm columns with this resin showed that the best flow rate of eluent is 2 ml/min. Also the most suitable volumes are 200 mL (HNO 3 0.05 M), 400 mL (solution of Thallium-203), 100 mL (H 2 O), 500 mL (Citric acid), 100 mL (H 2 0), 100 mL (EDTA 0.5 M and pH∼12.5). 60 mL (H 2 0), respectively

Normal results of post-race thallium-201 myocardial perfusion imaging in marathon runners with elevated serum MB creatine kinase levels

International Nuclear Information System (INIS)

Siegel, A.J.; Silverman, L.M.; Holman, B.L.

1985-01-01

Elevated cardiac enzyme values in asymptomatic marathon runners after competition can arise from skeletal muscle through exertional rhabdomyolysis, silent injury to the myocardium, or a combined tissue source. Peak post-race levels of the MB isoenzyme of creatine kinase are similar to values in patients with acute myocardial infarction. Previously reported normal results of infarct-avid myocardial scintigraphy with technetium 99m pyrophosphate in runners after competition suggest a non-cardiac source but cannot exclude silent injury to the myocardium. Therefore, thallium 201 myocardial perfusion imaging was performed in runners immediately after competition together with determination of sequential cardiac enzyme levels. Among 15 runners tested, the average peak in serum MB creatine kinase 24 hours after the race was 128 IU/liter with a cumulative MB creatine kinase release of 117 IU/liter; these values are comparable to those in patients with acute transmural myocardial infarction. Thallium 201 myocardial scintigraphic results were normal in five runners randomly selected from those who volunteered for determination of sequential blood levels. It is concluded that elevations of serum MB creatine kinase in marathon runners arise from a skeletal muscle source and that thallium 201 myocardial scintigraphy is useful to assess runners for myocardial injury when clinical questions arise

Spectral determination of thallium isotope composition

International Nuclear Information System (INIS)

Polyanskij, V.A.; Turkin, Yu.I.; Yakimova, N.M.

1986-01-01

The photoelectric non-standard method for determination of the thallium isotope composition is developed. The analysis is carried out by measuring the brightness of the Hfs components in the line Tl Iλ535.04 nm. The relative standard deviation of the results of the isotope analysis of thallium as metal is 0.02 and of thallium salts - 0.02-0.05

Exercise thallium-201 scintigraphy in the diagnosis and prognosis of coronary artery disease

International Nuclear Information System (INIS)

Kotler, T.S.; Diamond, G.A.

1990-01-01

The objective of this study is to determine the discriminant accuracy of exercise thallium-201 myocardial perfusion scintigraphy for the diagnosis and prognosis of patients with known or suspected coronary artery disease. This is a survey of the National Library of Medicine MEDLINE database. The key medical subject headings used were coronary disease, myocardial infarction, radionuclide imaging, and thallium. A total of 122 retrieved studies were considered relevant and were reviewed in depth. Only studies reporting both the sensitivity and specificity of thallium scintigraphy were analyzed. Discriminant accuracy for diagnosis and prognosis was summarized in terms of pooled sensitivity and specificity. Exercise thallium scintigraphy is useful in the noninvasive diagnosis of coronary artery disease, especially in patients with abnormal resting electrocardiograms, restricted exercise tolerance, and intermediate probability of having disease at the time of testing as well as of defining the prognosis of patients with known or suspected coronary artery disease, especially in those with previous myocardial infarction. Because of various shortcomings in the published record, however, the marginal discriminant accuracy and cost effectiveness of thallium scintigraphy compared with conventional clinical assessment and exercise electrocardiography remain controversial. 193 references

Qualification of viable myocardium in the infarcted area by dual isotope In-111 antimyosin Fab and thallium SPECT imaging

International Nuclear Information System (INIS)

Mitani, Isao; Nishimura, Tsunehiko; Uehara, Toshiisa; Hayashida, Kouhei; Kumita, Shin-ichirou; Oka, Hisatsugu; Haze, Kazuo; Nonoki, Hiroshi

1991-01-01

Dual isotope In-111 antimyosin (AM) Fab and thallium SPECT imaging was performed in 33 patients with acute myocardial infarction. Thirteen patients in whom coronary reperfusion could successfully be achieved at the acute stage had higher AM uptake parameters, including AM SCORE, AM AREA, and SCORE/AREA, and the maximum CPK value than the other 20 patients. Left ventricular ejection fraction had a stronger correlation with AM AREA than with AM SCORE (0.601 vs 0.387). Overlap phenomenon was seen in 18 patients (55%). In 28 patients followed up with coronary arteriography, 10 patients had a ≥75% coronary stenosis in the infarct-related vessel; 5 of these 10 had ischemic events. In 13 patients undergoing subsequent thallium-201 scintigraphy at rest, 6 (46%) were found to have marked reduction of perfusion defect (the improved group). Regarding thallium-201 DEFECT SCORE early after the onset of myocardial infarction, there was no significant difference between the aforementioned improved group (15±5) and the non-improved group (17±7). However, In-111 AM uptake in the infarct area was smaller in the improved group than the non-improved group, which means that the infarcted area did not become necrotic early after the onset of myocardial infarction. This may have been responsible for the improvement of perfusion defect in cases of myocardial infarction. (N.K.)

Preoperative magnetic resonance imaging protocol for endoscopic cranial base image-guided surgery.

Science.gov (United States)

Grindle, Christopher R; Curry, Joseph M; Kang, Melissa D; Evans, James J; Rosen, Marc R

2011-01-01

Despite the increasing utilization of image-guided surgery, no radiology protocols for obtaining magnetic resonance (MR) imaging of adequate quality are available in the current literature. At our institution, more than 300 endonasal cranial base procedures including pituitary, extended pituitary, and other anterior skullbase procedures have been performed in the past 3 years. To facilitate and optimize preoperative evaluation and assessment, there was a need to develop a magnetic resonance protocol. Retrospective Technical Assessment was performed. Through a collaborative effort between the otolaryngology, neurosurgery, and neuroradiology departments at our institution, a skull base MR image-guided (IGS) protocol was developed with several ends in mind. First, it was necessary to generate diagnostic images useful for the more frequently seen pathologies to improve work flow and limit the expense and inefficiency of case specific MR studies. Second, it was necessary to generate sequences useful for IGS, preferably using sequences that best highlight that lesion. Currently, at our institution, all MR images used for IGS are obtained using this protocol as part of preoperative planning. The protocol that has been developed allows for thin cut precontrast and postcontrast axial cuts that can be used to plan intraoperative image guidance. It also obtains a thin cut T2 axial series that can be compiled separately for intraoperative imaging, or may be fused with computed tomographic images for combined modality. The outlined protocol obtains image sequences effective for diagnostic and operative purposes for image-guided surgery using both T1 and T2 sequences. Copyright © 2011 Elsevier Inc. All rights reserved.

MR images of oral cancer treated with preoperative radiotherapy

International Nuclear Information System (INIS)

Onizawa, Kojiro; Niitsu Mamoru; Yusa, Hiroshi; Yanagawa, Toru; Yoshida, Hiroshi

2003-01-01

This study was carried out to evaluate the relationship between the effect of preoperative radiotherapy for oral cancer and the changes of signal intensity with MR images. T2-weighted images were compared before and after radiotherapy in 18 patients with primary oral cancer, and the effect on the lesions was histologically evaluated in surgically resected specimens obtained four weeks after the therapy. The MR images showed significantly decreased signal intensity of the lesions. The decrease of signal intensity was remarkable starting at two weeks after completion of the radiotherapy, compared with the decrease at less than two weeks after the therapy. The change of signal intensity was more obvious in tongue cancer than in other oral cancers. There was no significant difference in the change of the signal intensity between cancers with histologically poor response to the therapy and those with good response. These results suggested that signal intensity of oral cancer on T2-weighted images showed a significant decrease after preoperative radiotherapy, and that the intensity could be affected by duration after radiotherapy and primary sites. (author)

Thallium-201 scintigraphy of the heart in patients prior to aortocoronary bypass

International Nuclear Information System (INIS)

Nestaval, A.; Malek, I.; Jirickova, E.; Peregrin, J.; Kidery, J.; Oppelt, A.

1986-01-01

Scintigraphic examinations of the heart muscle were made using thallium-201 in 16 male patients with symptomatic ischemic heart disease, who were indicated for an aortocoronary bypass. The radionuclide was administered during exercise and the scintigrams were taken after 20 minutes and after 4 hours following administration. The images of the heart processed by computer were correlated with coronarographic findings. All 16 patients had stenoses of 1 to 3 coronary arteries. In 12 patients defects were found on the thallium scan in all areas corresponding to the coronarography, in the remaining four patients the defect was only on one of the affected branches of the coronary arteries. There were no false positive finding. The results suggest very satisfactory sensitivity of thallium scintigraphy in patients with severe coronary atherosclerosis. (author)

Comparison of myocardial blood flow induced by adenosine triphosphate and dipyridamole in patients with coronary artery disease

International Nuclear Information System (INIS)

Mamede, M.; Tadamura, Eiji; Hosokawa, Ryohei

2005-01-01

Myocardial perfusion imaging with adenosine triphosphate (ATP) has been used increasingly to diagnose coronary artery disease (CAD) and assess risk for this disease. This study compared absolute myocardial blood flow (MBF) and myocardial flow reserve index (MFR) with ATP and dipyridamole (DIP) in patients with CAD. MBF was quantified by 15 O-H 2 O PET in 21 patients with CAD (17 male, 4 female), aged 55 to 81 years. MBF was measured at rest, during intravenous injection of ATP (0.16 mg/kg/min), and again after DIP infusion (0.56 mg/kg). Regions of interest were drawn in nonischemic and ischemic segments based on findings from thallium-201 ( 201 Tl) scintigraphy and coronary angiography (CAG). Absolute MBF values and indexes of MFR were calculated in nonischemic and ischemic segments. Intravenous injection of ATP and DIP significantly increased MBF in nonischemic (2.4±0.9 and 2.1±0.8 ml/g/min, respectively; p<0.01, for both) and in ischemic segments (1.3±0.4 and 1.5±0.4 ml/g/min, respectively; p<0.01, for both). There was a significant difference in MBF values between ATP and DIP in nonischemic segments (p<0.05), which was not observed in ischemic segments. In nonischemic segments, ATP produced higher MFR than DIP (2.1±0.8 and 1.8±0.7, respectively; p<0.05), while no significant difference was observed in ischemic segments (1.5±0.6 and 1.7±0.3, respectively). ATP produced a greater hyperemia than DIP between the ischemic and nonischemic myocardium in patients with CAD. ATP is as effective as DIP for the diagnosis of CAD. (author)

High Performance Liquid Chromatographic Method for Determination of Dipyridamole in Human Plasma

Directory of Open Access Journals (Sweden)

DAVOOD BEIGI BAND ARAB ADI

1999-08-01

Full Text Available A simple, rapid and specific high-performance liquid chromatographic procedure is reported for"nquantitative determination of dipyridamole in human -plasma. The assay uses a reversed-phase"nhigh-performance liquid chromatographic (HPLC and UV detection at 280nm and has a limit"nof detection of approximately 5ng/mL. The mobile phase consists of MeOH-H20 (60:40"nadjusted to pH 3.3. Dipyridamole was extracted from plasma by back-extraction procedure, with"npropranolol as the internal standard. The reproducibility of the method is satisfactory

Is the antiproteinuric effect of dipyridamole hemodynamically mediated

NARCIS (Netherlands)

de Jong, P. E.; van der Meer, J.; van der Hem, G. K.; de Zeeuw, D.

1988-01-01

We studied the acute antiproteinuric and renal hemodynamic effect of dipyridamole 30–60 mg intravenously in 13 salt-depleted patients with the nephrotic syndrome of different etiology. Whereas mean arterial pressure did not change, a small fall in glomerular filtration rate with a concomitant fall

IRIS Toxicological Review of Thallium and Compounds (External Review Draft)

Science.gov (United States)

Thallium compounds are used in the semiconductor industry, the manufacture of optic lenses and low-melting glass, low-temperature thermometers, alloys, electronic devices, mercury lamps, fireworks, and imitation germs, and clinically as an imaging agent in the diagnosis of certai...

Pharmacologic intervention as an alternative to exercise stress

International Nuclear Information System (INIS)

Gould, K.L.

1987-01-01

Although thallium exercise imaging has served an important role in clinical cardiology, it is significantly limited by suboptimal sensitivity and specificity, particularly in asymptomatic man. The increasing recognition of silent myocardial ischemia, the significant prevalence of coronary artery disease in asymptomatic middle age men, and the frequent occurrence of myocardial infarction without preceding symptoms in 60% of cases emphasizes the need for a more definitive, noninvasive diagnostic test for the presence of coronary artery disease suitable for screening in asymptomatic or symptomatic patients. Intravenous dipyridamole combined with handgrip stress provides a potent stimulus for purposes of diagnostic perfusion imaging. Although planar and single photon emission computed tomography (SPECT) imaging also have played an important role, these techniques are seriously hindered by their inability to quantitate radiotracer uptake or image modest differences in maximum relative flow caused by coronary artery stenosis. Accordingly, the combination of dipyridamole-handgrip stress with positron imaging of myocardial perfusion has become a powerful diagnostic tool suitable for routine clinical use. With the availability of generator-produced rubidium-82, dedicated clinically oriented positron cameras, the routine application of positron imaging to clinical cardiology has become feasible. 75 references

Myocardial 201Tl washout after combined dipyridamole submaximal exercise stress: Reference values from different patient groups

International Nuclear Information System (INIS)

Fridrich, L.

1989-01-01

Dipyridamole stress is favorable in patients unable to exercise maximally for 201 Tl myocardial scintigraphy. Aside from an analysis of uptake defects, proper washout analysis can be limited by heart rate variations when isolated dipyridamole stress is used. Heart rate standardized 201 Tl washout kinetics after a combined dipyridamole and submaximal exercise stress protocol (CDSE), feasible in elderly patients as well as in patients with peripheral artery disease, were therefore studied to investigate the 201 Tl washout after CDSE in differently defined patient groups: Group I comprised 19 patients with documented heart disease and angiographically excluded coronary artery disease (CAD); group II contained 17 patients with a very low likelihood of CAD determined by both normal exercise radionuclide ventriculography and normal 201 Tl uptake. Group III comprised 56 patients with a 50% pretest likelihood of CAD but normal 201 Tl uptake. Mean washout values were nearly identical in all groups. Despite similar uptake patterns, however, washout standardized by CDSE was significantly lower than the normal washout values after maximal treadmill exercise. Thus an obviously lower 201 Tl washout after CDSE than after maximal treadmill exercise must be considered if washout analysis criteria after dipyridamole are applied to evaluate ischemic heart disease. Nevertheless, heart rate elevation achieved by additional submaximal exercise stress seems necessary, adequate and clinically safe for standardisation of washout analysis in dipyridamole 201 Tl scintigraphy. (orig.)

Isolation of radioactive thallium from lead targets

International Nuclear Information System (INIS)

Kozlova, M.D.; Sevast'yanova, A.S.; Malinin, A.B.; Kurenkov, N.V.

1989-01-01

Two methods of thallium-201 preperation from Pb-targets irradiated with protons: precipitation-extraction (1) and extraction (2) - are developed. When the target irraiated is extracted during the time necessary for bismuth-201 transformation into lead-201, lead macroquantity containing lead-201 was separated from undesirable thallium radionuclides, which are formed in direct nuclear reactions. The lead fraction was extracted to accumulate thallium-201, and it was separated from lead mocroquantity. The target was dissolved in the nitric acid. The 1st method differs from the 2nd one by the fact that before thallium-201 extraction, lead was precipitaed by the nitric acid. The 1st method permits to separate thallium-201 with chemical yield not less than 90 %, the 2nd one - ≥95 %. 2 refs

Myocardial perfusion scintigraphy with exercise and pharmacological stress

Energy Technology Data Exchange (ETDEWEB)

Sundram, F X [General Hospital of Singapore, Dept. of Nuclear Medicine (Senegal)

1996-12-31

Cardiac studies including myocardial perfusion scintigraphy was begun in the Singapore General Hospital, nuclear medicine department in 1983. From a few patients per year using planar imaging, we have in 1994 studied 1500 patients for myocardial perfusion, using mainly SPECT (single-photon emission computerised tomography) and radionuclides such as Thallium-201, Technetium-99m sestamibi and Tc-99m tetrofosmin. Patients have been stressed using treadmill exercise or pharmacological agents; we have used dipyridamole, and dobutamine for pharmacological stress but have no experience with intravenous adenosine.

Myocardial perfusion scintigraphy with exercise and pharmacological stress

International Nuclear Information System (INIS)

Sundram, F.X.

1995-01-01

Cardiac studies including myocardial perfusion scintigraphy was begun in the Singapore General Hospital, nuclear medicine department in 1983. From a few patients per year using planar imaging, we have in 1994 studied 1500 patients for myocardial perfusion, using mainly SPECT (single-photon emission computerised tomography) and radionuclides such as Thallium-201, Technetium-99m sestamibi and Tc-99m tetrofosmin. Patients have been stressed using treadmill exercise or pharmacological agents; we have used dipyridamole, and dobutamine for pharmacological stress but have no experience with intravenous adenosine

Thallium in mineral resources extracted in Poland

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Bojakowska I.

2013-04-01

Full Text Available Thallium concentrations in primary mineral commodities extracted in Poland and processed in high temperatures were determined by ICP-MS method. Samples of hard and brown coal, copper-silver and zinclead ores, argillaceous and calcareous rocks of different genesis and age were analyzed. The highest thallium concentrations occur in the zinc-lead ores, the average content being of 52.1 mg/kg. The copper ores contain in average 1.4 mg/kg of thallium. Hard coals from the Upper Silesian Coal Basin display higher thallium content than those exploited in the Lublin Coal Basin. Brown coals from Turow deposit distinguish by much higher values, 0.7 mg/kg Tl, than those from huge Bełchatów and smaller Konin-Turek region deposits. Average thallium concentrations in clays used for ceramic materials are lower than 1 mg/kg, except of Mio-Pliocene Slowiany deposit. The average content of thallium in the studied limestone and dolomite raw materials for cement, lime, and metallurgical flux, and refractories is very low in comparison to the average amounts in the world carbonate rocks.

Thallium-201 myocardial perfusion imaging during adenosine-induced coronary vasodilation in patients with ischemic heart disease

International Nuclear Information System (INIS)

Takeishi, Yasuchika; Chiba, Junya; Abe, Shinya

1992-01-01

Thallium-201 ( 201 Tl) myocardial perfusion imaging during adenosine infusion was performed in consecutive 55 patients with suspected coronary artery disease. Adenosine was infused intravenously at a rate of 0.14 mg/kg/min for 6 minutes and a dose of 111 MBq of 201 Tl was administered in a separate vein at the end of third minutes of infusion. Myocardial SPECT imaging was begun 5 minutes and 3 hours after the end of adenosine infusion. For evaluating the presence of perfusion defects, 2 short axis images at the basal and spical levels and a vertical long axis image at the mid left ventricle were used. The regions with decreased 201 Tl uptake were assessed semi-quantitatively. Adenosine infusion caused a slight reduction in systolic blood pressure and an increase in heart rate. The rate pressure products increased slightly (9314±2377 vs. 10360±2148, p 201 Tl myocardial imaging during adenosine infusion was considered to be safe and useful for evaluating the patients with ischemic heart disease. (author)

Impact of magnetic resonance imaging on preoperative planning for breast cancer surgery.

Science.gov (United States)

Law, Y; Cheung, Polly S Y; Lau, Silvia; Lo, Gladys G

2013-08-01

To review the impact of preoperative breast magnetic resonance imaging on the management of planned surgery, and the appropriateness of any resulting alterations. Retrospective review. A private hospital in Hong Kong. PATIENTS; For the 147 consecutive biopsy-proven breast cancer patients who underwent preoperative magnetic resonance imaging to determine tumour extent undergoing operation by a single surgeon between 1 January 2006 and 31 December 2009, the impact of magnetic resonance imaging findings was reviewed in terms of management alterations and their appropriateness. The most common indication for breast magnetic resonance imaging was the presence of multiple indeterminate shadows on ultrasound scans (53%), followed by ill-defined border of the main tumour on ultrasound scans (19%). In 66% (97 out of 147) of the patients, the extent of the operation was upgraded. Upgrading entailed: lumpectomy to wider lumpectomy (23 out of 97), lumpectomy to mastectomy (47 out of 97), lumpectomy to bilateral lumpectomy (15 out of 97), and other (12 out of 97). Mostly, these management changes were because magnetic resonance imaging showed more extensive disease (n=29), additional cancer foci (n=39), or contralateral disease (n=24). In five instances, upgrading was due to patient preference. In 34% (50 out of 147) of the patients, there was no change in the planned operation. Regarding 97 of the patients having altered management, in 12 the changes were considered inappropriately extensive (due to false-positive magnetic resonance imaging findings). In terms of magnetic resonance imaging detection of more extensive, multifocal, multicentric, or contralateral disease, the false-positive rate was 13% and false-negative rate 7%. Corresponding rates for sensitivity and specificity were 95% and 81%, using the final pathology as the gold standard. Preoperative magnetic resonance imaging had a clinically significant and mostly correct impact on management plans. Magnetic resonance

Diagnostic value of exercise stress testing, dipyridamole stress-echocardiography and perfusion stress-scintigraphy for identification of coronary artery disease in women

International Nuclear Information System (INIS)

Debnath, S.; Tyrnovska-Kydreva, R.; Khalacheva, S.; Radoslavova, R.; Stoyanova, N.; Draganov, T.; Elenkova, A.; Garcheva, M.; Shejretova, E.

1995-01-01

To compare the value of exercise stress testing (EST), dipyridamole stress echocardiography and 99m Tc-methoxy-isobutyl-isonitrile (MIBI)-planer scintigraphy, 75 female patients with angina pectoris who underwent coronary angiography were studied. Significant (≥50% stenosis) coronary artery disease (CAD) was present in 38 of the patients. EST was performed in all of the patients but dipyridamole echocardiography and MIBI-planer scintigraphy - in 36 of them (22 with and 14 without CAD). Compared with dipyridamole echocardiography, EST and MIBI-planer scintigraphy had a significantly higher sensitivity (74% vs 45%, p<0.01 and 82% vs 45%, p<0.01, respectively). There was no significant difference in sensitivity between EST and MIBI-planer scintigraphy. Dipyridamole echocardiography and MIBI-planer scintigraphy showed a higher specificity than EST (93% vs 54%, p<0.01 and 93% vs 54%, p<0.01, respectively). Diagnostic accuracy of MIBI-planer scintigraphy was higher than that of dipyridamole echocardiography and EST (86% vs 64%, p<0.05 and 86 vs 64%, p<0.01, respectively). Thus, MIBI-planer scintigraphy appears to be superior to EST and dipyridamole echocardiography for the evaluation of CAD in symptomatic women. 20 refs., 2 tabs. (author)

The value and throughput of rest Thallium-201/stress Technetium -99m sestamibi dual-isotope myocardial SPECT.

Science.gov (United States)

Okudan, Berna; Smitherman, Thomas C

2004-06-01

Myocardial perfusion scintigraphy is an established method in cardiology for the diagnosis and evaluation of coronary artery disease (CAD). Thallium-201 and Tc-99m sestamibi myocardial perfusion imaging has been widely accepted as non-invasive diagnostic procedure for detection of CAD, risk stratification and myocardial viability assessment. But, standard Tl-201 redistribution and same day or 2-day rest/stress Tc-99m sestamibi protocols are time-consuming. Hence, the dual isotope rest thallium-201/stress technetium-99m sestamibi gated single-photon emission tomography protocol has gained increasing popularity for these applications. Combining the use of thallium-201 with technetium-99m agents permits optimal image resolution and simultaneous assessment of viability. Dual-isotope imaging may be separate or simultaneous acquisition set-up. The more rapid completion of these studies is appreciated as an advantage by patients, technologists, interpreting and referring physicians, nurses and hospital management. Simultaneous imaging has the potential advantages of precise pixel registration and artifacts, if present, are identical in both thallium and sestamibi, and require only one set of imaging. Also, there are some disadvantages of spillover of activity from the Tc-99m to the Tl-201 window. Fortunately, despite this problem it can be overcome. Separate acquisition dual isotope also has some disadvantages. Difference in defect resolution in attenuation and scatter between T-201 and Tc-99m sestamibi potentially results in interpretation problems. But, studies about cost-effectiveness of dual isotope imaging showed that some selective elimination of the rest studies may decrease the cost of the nuclear procedures and should be considered in the current care health system.

Can preoperative MR imaging predict optic nerve invasion of retinoblastoma?

International Nuclear Information System (INIS)

Song, Kyoung Doo; Eo, Hong; Kim, Ji Hye; Yoo, So-Young; Jeon, Tae Yeon

2012-01-01

Purpose: To evaluate the accuracy of pre-operative MRI for the detection of optic nerve invasion in retinoblastoma. Materials and methods: Institutional review board approval and informed consent were waived for this retrospective study. A total of 41 patients were included. Inclusion criteria were histologically proven retinoblastoma, availability of diagnostic-quality preoperative MR images acquired during the 4 weeks before surgery, unilateral retinoblastoma, and normal-sized optic nerve. Two radiologists retrospectively reviewed the MR images independently. Five imaging findings (diffuse mild optic nerve enhancement, focal strong optic nerve enhancement, optic sheath enhancement, tumor location, and tumor size) were evaluated against optic nerve invasion of retinoblastoma. The predictive performance of all MR imaging findings for optic nerve invasion was also evaluated by the receiver operating characteristic curve analysis. Results: Optic nerve invasion was histopathologically confirmed in 24% of study population (10/41). The differences in diffuse mild enhancement, focal strong enhancement, optic sheath enhancement, and tumor location between patients with optic nerve invasion and patients without optic nerve invasion were not significant. Tumor sizes were 16.1 mm (SD: 2.2 mm) and 14.9 mm (SD: 3.6 mm) in patients with and without optic nerve involvement, respectively (P = 0.444). P-Values from binary logistic regression indicated that all five imaging findings were not significant predictors of tumor invasion of optic nerve. The AUC values of all MR imaging findings for the prediction of optic nerve invasion were 0.689 (95% confidence interval: 0.499–0.879) and 0.653 (95% confidence interval: 0.445–0.861) for observer 1 and observer 2, respectively. Conclusion: Findings of MRI in patients with normal-sized optic nerves have limited usefulness in preoperatively predicting the presence of optic nerve invasion in retinoblastoma.

Can preoperative MR imaging predict optic nerve invasion of retinoblastoma?

Energy Technology Data Exchange (ETDEWEB)

Song, Kyoung Doo, E-mail: kdsong0308@gmail.com [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50, Ilwon-Dong, Kangnam-Ku, Seoul 135-710 (Korea, Republic of); Eo, Hong, E-mail: rtombow@gmail.com [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50, Ilwon-Dong, Kangnam-Ku, Seoul 135-710 (Korea, Republic of); Kim, Ji Hye, E-mail: jhkate.kim@samsung.com [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50, Ilwon-Dong, Kangnam-Ku, Seoul 135-710 (Korea, Republic of); Yoo, So-Young, E-mail: sy1131.yoo@samsung.com [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50, Ilwon-Dong, Kangnam-Ku, Seoul 135-710 (Korea, Republic of); Jeon, Tae Yeon, E-mail: hathor97.jeon@samsung.com [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50, Ilwon-Dong, Kangnam-Ku, Seoul 135-710 (Korea, Republic of)

2012-12-15

Purpose: To evaluate the accuracy of pre-operative MRI for the detection of optic nerve invasion in retinoblastoma. Materials and methods: Institutional review board approval and informed consent were waived for this retrospective study. A total of 41 patients were included. Inclusion criteria were histologically proven retinoblastoma, availability of diagnostic-quality preoperative MR images acquired during the 4 weeks before surgery, unilateral retinoblastoma, and normal-sized optic nerve. Two radiologists retrospectively reviewed the MR images independently. Five imaging findings (diffuse mild optic nerve enhancement, focal strong optic nerve enhancement, optic sheath enhancement, tumor location, and tumor size) were evaluated against optic nerve invasion of retinoblastoma. The predictive performance of all MR imaging findings for optic nerve invasion was also evaluated by the receiver operating characteristic curve analysis. Results: Optic nerve invasion was histopathologically confirmed in 24% of study population (10/41). The differences in diffuse mild enhancement, focal strong enhancement, optic sheath enhancement, and tumor location between patients with optic nerve invasion and patients without optic nerve invasion were not significant. Tumor sizes were 16.1 mm (SD: 2.2 mm) and 14.9 mm (SD: 3.6 mm) in patients with and without optic nerve involvement, respectively (P = 0.444). P-Values from binary logistic regression indicated that all five imaging findings were not significant predictors of tumor invasion of optic nerve. The AUC values of all MR imaging findings for the prediction of optic nerve invasion were 0.689 (95% confidence interval: 0.499–0.879) and 0.653 (95% confidence interval: 0.445–0.861) for observer 1 and observer 2, respectively. Conclusion: Findings of MRI in patients with normal-sized optic nerves have limited usefulness in preoperatively predicting the presence of optic nerve invasion in retinoblastoma.

Is pre-operative imaging essential prior to ureteric stone surgery?

Science.gov (United States)

Youssef, F R; Wilkinson, B A; Hastie, K J; Hall, J

2012-09-01

The aim of this study was to identify patients not requiring ureteric stone surgery based on pre-operative imaging (within 24 hours) prior to embarking on semirigid ureteroscopy (R-URS) for urolithiasis. The imaging of all consecutive patients on whom R-URS for urolithiasis was performed over a 12-month period was reviewed. All patients had undergone a plain x-ray of the kidney, ureters and bladder (KUB), abdominal non-contrast computed tomography (NCCT-KUB) or both on the day of surgery. A total of 96 patients were identified for the study. Stone sizes ranged from 3 mm to 20 mm. Thirteen patients (14%) were cancelled as no stone(s) were identified on pre-operative imaging. Of the patients cancelled, 8 (62%) required NCCT-KUB to confirm spontaneous stone passage. One in seven patients were stone free on the day of surgery. This negates the need for unnecessary anaesthetic and instrumentation of the urinary tract, with the associated morbidity. Up-to-date imaging prior to embarking on elective ureteric stone surgery is highly recommended.

Radiometric titration of thallium(III) with EDTA

International Nuclear Information System (INIS)

Rao, V.R.S.; Pulla Rao, Ch.; Tataiah, G.

1978-01-01

Radioactive solutions containing very small amounts of thallium(III) can be determined by radiometric titration using ammonia as hydrolysing agent. Aqueous solution of thallium(I) (both inactive and radioactive) is treated with bromine water till the appearance of the brown colour of bromine, and the solution is warmed to 80 deg C to expel the excess bromine. By this procedure all thallium(I) is quantitatively oxidised to thallium(III). An aqueous solution of ammonia is added to precipitate thallium(III) as thallic oxide. It is then filtered, washed with water to free it from bromide and then dissolved in 2N HCl and the solution is then standardised. 2 ml of this solution is transferred to a 20 ml volumetric flask, 1 ml of radioactive thallium(III) solution to be standardised is added as well as incremental amounts of EDTA solution and mixed thoroughly. Uncomplexed thallium(III) is then precipitated by the addition of an ammonia solution and diluted to 20 ml. Required amount of this mixture is centrifuged. The beta activity of the supernatant aliquot is measured using a GM counter. Quantitative determination of Tl(III) in the range of 1-10 μM can be carried out. The interference of cations such as Au(III), iron(III), Ga(III) can be eliminated by pretreatment of the Tl(III) solution before carrying out radiometric titration. The results obtained are reproducible and accurate to +-3%. (T.I.)

Value of the 201-Thallium scintigram in the diagnosis of coronary artery disease in patients with and without myocardial infraction

International Nuclear Information System (INIS)

Silber, S.; Klein, U.; Rudolph, W.

1980-01-01

The usefulness and limitations of the 201-thallium scintigram in the detection of myocardial hypoperfusions is dependent on the sensitivity, specificity and predictive value of the method. The presence of myocardial hypoperfusion can be diagnosed with certainly from a pathologic scintigram only in the absence of false positive scintigrams. Such a high specificity can be achieved only by desginating markedly positive scintigrams as pathologic findings. This, however, necessarily incurs a reduction in sensitivity. In coronary artery disease with previous myocardial infarction, the sensitivity is primarily dependent on the extent of infarction. In coronary arterx desease with no previous myocardial infarction, the sensitivity of the thallium scintigram in patients with 2-vessel disease was found to be less than that of those with 1-vessel disease and 3-vessel disease. As compared with the exercise ECG, the scintigram was more sensitive only in patients with 1-vessel but less sensitive in those patients with 2-vessel and 3-vessel disease. The thallium scintigram is indicated for patients with atypical chest pain, when angina pectoris cannot be ruled out and when the exercise ECG is borderline or non-interpretable. The thallium scintigram is also indicated for asymptomatic patients with a markedly positive exercise ECG. The thallium scintigram yields no additional information relative to the question of presence or absence of myocardial hypoperfusion in patients with typical angina pectoris. In patients with a history of, but with no electrocardiographic criteria for myocardial infarction, the scintigram seems to be of only limited valued. The thallium scintigram is a valuable adjunct in the assessment of the results of coronary artery bypass surgery provided that a pre-operative study is available for comparison. (orig./MG) [de

Thallium (III) salts utilization in organic synthesis. Part II

International Nuclear Information System (INIS)

Ferraz, H.M.C.

1989-01-01

The utilizations of thallium (III) salts in organic synthesis with carbonylic and acitylenic substrates are presented. The reactions of carbonylic substra3ts with kitones and the oxidation reactions of acetylenic substrates are shown. Others reactions including thallium (III) salts and non aromatic unsatured substracts, as cleasage of ethers and epoxide using thallium trinitrate, hydrazones treatments with thallium triacetates, etc, are also mentioned. (C.G.C.) [pt

Exercise thallium-201 scintigraphy in men with nondiagnostic exercise electrocardiograms. Prognostic implications

International Nuclear Information System (INIS)

Iskandrian, A.S.; Hakki, A.H.; Kane-Marsch, S.

1986-01-01

We studied the prognostic value of exercise thallium-201 imaging in 196 men with suspected or known coronary artery disease who had nondiagnostic exercise electrocardiograms. The perfusion images in each of three projections were divided into three segments; each segment was assessed for perfusion defects (fixed or reversible). There were 12 cardiac events at a mean follow-up of 15 months (range, one to 66 months). Of those, five patients died of cardiac causes and seven had nonfatal acute myocardial infarctions (MIs). Only the number of perfusion defects significantly predicted cardiac events; clinical presentation, history of MI, presence of Q-wave MI, exercise duration, and exercise heart rate and double product did not predict cardiac events or add to information provided by the number of defects. Furthermore, actuarial life-table analysis showed that patients with three or more perfusion defects had significantly worse prognoses than patients with fewer than three defects. Exercise thallium-201 imaging helps in risk stratification of men with nondiagnostic exercise electrocardiograms

Myocardial thallium-201 kinetics in normal and ischemic myocardium

International Nuclear Information System (INIS)

Grunwald, A.M.; Watson, D.D.; Holzgrefe, H.H. Jr.; Irving, J.F.; Beller, G.A.

1981-01-01

The net myocardial accumulation of thallium-201 after injection depends upon the net balance between continuing myocardial extraction from low levels of recirculating thallium in the blood compartment and the net rate of efflux of thallium from the myocardium into the extracardiac blood pool. These experiments were designed to measure separately the myocardial extraction and intrinsic myocardial efflux of thallium-201 at normal and at reduced rates of myocardial blood flow. The average myocardial extraction fraction at normal blood flow in 10 anesthetized dogs was 82 +/- 6% (+/- SD) at normal coronary arterial perfusion pressures and increased insignificantly, to 85 +/- 7%, at coronary perfusion pressures of 10--35 mm Hg. At normal coronary arterial perfusion pressures in 12 additional dogs, the intrinsic thallium washout in the absence of systemic recirculation had a half-time (T 1/2) of 54 +/- 7 minutes. The intrinsic cellular washout rate began to increase as distal perfusion pressures fell below 60 mm Hg and increased markedly to a T 1/2 of 300 minutes at perfusion pressures of 25--30 mm Hg. A second, more rapid component of intrinsic thallium washout (T 1/2 2.5 minutes) representing approximately 7% of the total initially extracted myocardial thallium was observed. The faster washout component is presumed to be due to washout of interstitial thallium unextracted by myocardial cells, whereas the slower component is presumed due to intracellular washout. The net clearance time of thallium measured after i.v. injection is much longer than the intrinsic myocardial cellular washout rate because of continuous replacement of myocardial thallium from systemic recirculation. Myocardial redistribution of thallium-201 in states of chronically reduced perfusion cannot be the result of increased myocardial extraction efficiency, but rather, is the result of the slower intrinsic cellular washout rate at reduced perfusion levels

[Performance of Thallium 201 rest-redistribution spect to predict viability in recent myocardial infarction].

Science.gov (United States)

Coll, Claudia; González, Patricio; Massardo, Teresa; Sierralta, Paulina; Humeres, Pamela; Jofré, Josefina; Yovanovich, Jorge; Aramburú, Ivonne; Brugère, Solange; Chamorro, Hernán; Ramírez, Alfredo; Kunstmann, Sonia; López, Héctor

2002-03-01

The detection of viability after acute myocardial infarction is primordial to select the most appropriate therapy, to decrease cardiac events and abnormal remodeling. Thallium201 SPECT is one of the radionuclide techniques used to detect viability. To evaluate the use of Thallium201 rest-redistribution SPECT to detect myocardial viability in reperfused patients after a recent myocardial infarction. Forty one patients with up to of 24 days of evolution of a myocardial infarction were studied. All had angiographically demonstrated coronary artery disease and were subjected to a successful thrombolysis, angioplasty or bypass grafting. SPECT Thallium201 images were acquired at rest and after 4 h of redistribution. These results were compared with variations in wall motion score, studied at baseline and after 3 or 4 months with echocardiography. The sensitivity of rest-redistribution Thallium201 SPECT, to predict recovery of wall motion was 91% when patient analysis was performed and 79% when segmental analysis was done in the culprit region. The figures for specificity were 56 and 73% respectively. Rest-distribution Thallium201 SPECT has an excellent sensitivity to predict myocardial viability in recent myocardial infarction. The data obtained in this study is similar to that reported for chronic coronary artery disease.

Thallium-201 scintigraphy in diagnosis of coronary stenosis

International Nuclear Information System (INIS)

Corne, R.A.; Gotsman, M.S.; Weiss, A.; Enlander, D.; Samuels, L.D.; Salomon, J.A.; Warshaw, B.; Atlan, H.

1979-01-01

The sensitivity of rest and exercise thallium-201 scintigraphy for the detection of significant coronary artery disease and myocardial ischaemia was compared with rest and exercise electrocardiography in 46 patients with chest pain. Of 26 patients with greater that 70 per cent coronary stenosis, 16 had abnormal rest thallium-201 scintigrams and 13 had Q waves. Myocardial perfusion defects in the resting scintigram correlated very well with evidence of previous myocardial infarction (16 of 17 patients, 94%) significant Q waves were present in 13 of these 17 patients (76%). After exercise, abnormal thallium-201 scintigrams consistent with ischaemia were found in 21 patients (81%). Abnormal exercise electrocardiograms were present in 15 patients (58%). The combination of abnormal exercise thallium-201 scintigrams or exercise electrocardiograms (23/26, 88%) exceeded abnormal exercise electrocardiograms alone (15/26, 58%). The two procedures were thus complementary. Abnormal rest or exercise thallium-201 scintigrams were obtained in 25/26 patients (96%) compared with abnormal rest or exercise electrocardiograms in 21/26 patients (84%). Twenty patients with less than 50 per cent coronary stenosis had normal rest thallium-201 scintigrams and no Q waves. Two had abnormal exercise thallium-201 scintigrams and 7 had abnormal exercise electrocardiograms. Thus,exercise thallium scintigraphy has higher sensitivity than exercise electrocardiography in detecting exercise induced ischaemia and is more specific. Scintigraphy appears to have a higher sensitivity than electrocardiography in detecting coronary artery disease. (author)

Thallium-201 myocardial perfusion imaging at rest and during exercise. Comparative sensitivity to electrocardiography in coronary artery disease

International Nuclear Information System (INIS)

Bailey, I.K.; Griffith, L.S.C.; Rouleau, J.; Strauss, H.W.; Pitt, B.

1977-01-01

The sensitivity of myocardial perfusion imaging (MPI) using thallium-201 injected both at rest and during peak exercise was compared to simultaneously recorded 12 lead electrocardiography (ECG) for the detection of transient ischemia in 20 normal subjects and 63 patients with coronary artery disease (CAD). No significant perfusion defects or ECG changes were seen on either the rest or exercise studies in any of the normal subjects. Fifty-six percent of patients with CAD developed new perfusion defects with exercise compared to 38 percent who developed ischemic ST-segment depression (P < 0.02). However, when chest pain and/or ST depression were considered indices of ischemia, the sensitivity of exercise testing and thallium-201 MPI was similar. The increased sensitivity of MPI compared to ST-segment depression on the ECG was due to patients with baseline ECG abnormalities and those who failed to achieve 85 percent of predicted maximum heart rate with exercise. Analysis of the exercise results according to the extent of coronary artery disease revealed a progressive increase in both positive ECGs and MPI with the number of vessels involved. In patients with single vessel disease the MPI was more sensitive than the ECG (P < 0.02). The combination of the rest and exercise ECG, MPI and chest pain during exercise failed to identify 11 percent of patients with CAD. Exercise thallium-201 MPI is a useful adjunct to conventional exercise testing particularly when evaluating patients with abnormal resting ECGs, those who develop ventricular conduction defects or arrhythmias during exercise, and those who fail to achieve their predicted heart rate because of fatigue or breathlessness

Rest thallium-201 myocardial perfusion imaging in a patient with leukaemic infiltration of the heart

International Nuclear Information System (INIS)

Civelek, A.C.; Camargo, E.E.; Links, J.M.; Brinker, J.A.; Wagner, H.N. Jr.

1992-01-01

Despite the high incidence of leukaemic infiltration of the heart, only 8 cases of atrioventricular block due to leukemia have been reported in the literature. Improvement in the heart block associated with disappearance of the leukaemic infiltrate has not been reported. A rest thallium-201 study was used in a 65-year-old man to demonstrate leukaemic infiltration of the heart which was associated with complete heart block. After chemotherapy, when the tumour burden was reduced and the leukaemia in remission, his heart block resolved, and a follow-up thallium scan was normal. (orig.)

Aspirin plus dipyridamole versus aspirin alone after cerebral ischaemia of arterial origin (ESPRIT): randomised controlled trial.

Science.gov (United States)

Halkes, P H A; van Gijn, J; Kappelle, L J; Koudstaal, P J; Algra, A

2006-05-20

Results of trials of aspirin and dipyridamole combined versus aspirin alone for the secondary prevention of vascular events after ischaemic stroke of presumed arterial origin are inconsistent. Our aim was to resolve this uncertainty. We did a randomised controlled trial in which we assigned patients to aspirin (30-325 mg daily) with (n=1363) or without (n=1376) dipyridamole (200 mg twice daily) within 6 months of a transient ischaemic attack or minor stroke of presumed arterial origin. Our primary outcome event was the composite of death from all vascular causes, non-fatal stroke, non-fatal myocardial infarction, or major bleeding complication, whichever happened first. Treatment was open, but auditing of outcome events was blinded. Primary analysis was by intention to treat. This study is registered as an International Standard Randomised Controlled Trial (number ISRCTN73824458) and with (NCT00161070). Mean follow-up was 3.5 years (SD 2.0). Median aspirin dose was 75 mg in both treatment groups (range 30-325); extended-release dipyridamole was used by 83% (n=1131) of patients on the combination regimen. Primary outcome events arose in 173 (13%) patients on aspirin and dipyridamole and in 216 (16%) on aspirin alone (hazard ratio 0.80, 95% CI 0.66-0.98; absolute risk reduction 1.0% per year, 95% CI 0.1-1.8). Addition of the ESPRIT data to the meta-analysis of previous trials resulted in an overall risk ratio for the composite of vascular death, stroke, or myocardial infarction of 0.82 (95% CI 0.74-0.91). Patients on aspirin and dipyridamole discontinued trial medication more often than those on aspirin alone (470 vs 184), mainly because of headache. The ESPRIT results, combined with the results of previous trials, provide sufficient evidence to prefer the combination regimen of aspirin plus dipyridamole over aspirin alone as antithrombotic therapy after cerebral ischaemia of arterial origin.

Interstitial adenosine concentration is increased by dipyridamole

International Nuclear Information System (INIS)

Gorman, M.W.; Wangler, R.D.; DeWitt, D.F.; Wang, C.Y.; Bassingthwaighte, J.B.; Sparks, H.V.

1986-01-01

The authors used the multiple indicator dilution technique to observe the capillary transport of adenosine (ADO) in isolated guinea pig hearts. Radiolabelled albumin, sucrose and ADO were injected on the arterial side and measured in venous samples collected during the following 20 seconds. Transport parameters calculated from these data include permeability-surface area products (PS) for transendothelial diffusion, endothelial cell (EC) uptake at the lumenal and ablumenal membranes, and EC metabolism. With simultaneous measurements of arterial and venous ADO concentrations and flow, the authors calculated the steady-state interstitial fluid (ISF) ADO concentration. Under control conditions the venous ADO concentration was 7.1 +/- 2.8 nM. The calculated ISF concentration depends on whether they assume the venous ADO comes from the ISF, or directly from ECs. These ISF concentrations are 25 +/- 12 nM and 9.8 +/- 4.0 nM, respectively. During dipyridamole infusion (10 uM) the EC transport parameters became nearly zero. Venous and ISF ADO concentrations increased to 33 +/- 8.9 nM and 169 +/- 42 nM, respectively. The authors conclude that the ISF ADO concentration is 1.5-4 fold higher than the venous concentration at rest, and the ISF concentration increases greatly with dipyridamole

A fatal case of thallium toxicity: challenges in management.

Science.gov (United States)

Riyaz, R; Pandalai, S L; Schwartz, M; Kazzi, Z N

2013-03-01

Thallium is a highly toxic compound and is occasionally involved in intentional overdoses or criminal poisonings. Accidental poisonings also occur, but are increasingly rare owing to restricted use and availability of thallium. We report a fatal suicidal ingestion of thallium sulfate rodenticide in which multi-dose activated charcoal (MDAC) and Prussian Blue (PB) were both used without changing the outcome. A 36 year old man ingested an unknown amount of thallium sulfate grains from an old rodenticide bottle. He presented to an emergency department (ED) 45 minutes later with abdominal pain and vomiting. On examination he was agitated with a blood pressure of 141/60 mmHg and a heart rate of 146 beats per minute (bpm). He received MDAC during his initial ED management and was started on PB 18 hours post arrival; he was intubated on the following day for airway protection. The patient continued to be tachycardic and hypertensive and subsequently developed renal failure. On hospital day three, the patient developed hypotension that did not respond to fluids. The patient required vasopressors and was transferred to a tertiary care center to undergo continuous renal replacement therapy (CRRT). The patient died shortly after his transfer. His last blood thallium concentration was 5369 mcg/L, a spot urine thallium >2000 mcg/L, and a 24- hour urine thallium was >2000 mcg/L. Though extremely rare, thallium intoxication can be lethal despite early administration of MDAC and use of Prussian blue therapy. Rapid initiation of hemodialysis can be considered in cases of severe thallium poisoning, to remove additional thallium, to correct acid-base disturbance, or to improve renal function.

Reproducibility of quantitative planar thallium-201 scintigraphy: quantitative criteria for reversibility of myocardial perfusion defects

International Nuclear Information System (INIS)

Sigal, S.L.; Soufer, R.; Fetterman, R.C.; Mattera, J.A.; Wackers, F.J.

1991-01-01

Fifty-two paired stress/delayed planar 201 TI studies (27 exercise studies, 25 dipyridamole studies) were processed twice by seven technologists to assess inter- and intraobserver variability. The reproducibility was inversely related to the size of 201 Tl perfusion abnormalities. Intraobserver variability was not different between exercise and dipyridamole studies for lesions of similar size. Based upon intraobserver variability, objective quantitative criteria for reversibility of perfusion abnormalities were defined. These objective criteria were tested prospectively in a separate group of 35 201 Tl studies and compared with the subjective interpretation of quantitative circumferential profiles. Overall, exact agreement existed in 78% of images (kappa statistic k = 0.66). We conclude that quantification of planar 201 Tl scans is highly reproducible, with acceptable inter- and intraobserver variability. Objective criteria for lesion reversibility correlated well with analysis by experienced observers

Comparison between exercise electrocardiogram and thallium 201 myocardial perfusion imaging during exercise, after dipyridamole and at rest, for the diagnosis of stable angina pectoris. 176 cases were studied with coronary angiography

International Nuclear Information System (INIS)

Machecourt, J.; Denis, B.; Comet, M.; Wolf, J.E.; Dimitriou, R.; Pellet, J.; Noel, P.M.

1981-01-01

The purpose of this study was to compare the diagnostic interest of the electrocardiogram stress test (EST) and the thallium myocardial imaging during exercise (TIE). For this, the cases of 176 patients with stable angina pectoris who underwent a coronary arteriogram were studied. These patients were divided into two groups: a first group of 113 patients without a previous history of myocardial infarction, nor a Q wave on their electrocardiogram and a second group of 63 patients with angina pectoris after a previous myocardial infarction. All patients underwent a combined EST and TIE. The sensitivity and the specificity of the EST and the TIE were studied, and the post-test risk after either a positive test or a negative test was calculated according to Bayes' theorem. In the first group 62 patients had a coronary stenosis and 51 had a normal arteriogram. The sensitivity of the TIE was higher than that of the EST: 80% versus 64%, p < 0.01. Even when the maximum effort was not reached during the EST, the TIE kept the same sensitivity. The diagnosis of angina pectoris cannot be absolutely established by the separate use of the TIE or the EST. However, their predictive value increases when both are correlated. Moreover, for female patients, the TIE is more specific than the EST because of the higher frequency of false positive or equivocal results of the EST in that population. (Auth.)

Preoperative subtyping of meningiomas by perfusion MR imaging

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Zhang, Hao [University Medical Center Groningen, University of Groningen (Netherlands); Shanghai Jiaotong University affiliated First People' s Hospital, Department of Radiology, Shanghai (China); Department of Radiology, University of Groningen (Netherlands); Roediger, Lars A.; Oudkerk, Matthijs [University Medical Center Groningen, University of Groningen (Netherlands); Department of Radiology, University of Groningen (Netherlands); Shen, Tianzhen [Fudan University Huashan Hospital, Department of Radiology, Shanghai (China); Miao, Jingtao [Shanghai Jiaotong University affiliated First People' s Hospital, Department of Radiology, Shanghai (China)

2008-10-15

This paper aims to evaluate the value of perfusion magnetic resonance (MR) imaging in the preoperative subtyping of meningiomas by analyzing the relative cerebral blood volume (rCBV) of three benign subtypes and anaplastic meningiomas separately. Thirty-seven meningiomas with peritumoral edema (15 meningothelial, ten fibrous, four angiomatous, and eight anaplastic) underwent perfusion MR imaging by using a gradient echo echo-planar sequence. The maximal rCBV (compared with contralateral normal white matter) in both tumoral parenchyma and peritumoral edema of each tumor was measured. The mean rCBVs of each two histological subtypes were compared using one-way analysis of variance and least significant difference tests. A p value less than 0.05 indicated a statistically significant difference. The mean rCBV of meningothelial, fibrous, angiomatous, and anaplastic meningiomas in tumoral parenchyma were 6.93{+-}3.75, 5.61{+-}4.03, 11.86{+-}1.93, and 5.89{+-}3.85, respectively, and in the peritumoral edema 0.87{+-}0.62, 1.38{+-}1.44, 0.87{+-}0.30, and 3.28{+-}1.39, respectively. The mean rCBV in tumoral parenchyma of angiomatous meningiomas and in the peritumoral edema of anaplastic meningiomas were statistically different (p<0.05) from the other types of meningiomas. Perfusion MR imaging can provide useful functional information on meningiomas and help in the preoperative diagnosis of some subtypes of meningiomas. (orig.)

Radioprotection by dipyridamole in the aging mouse. Effects on lipid peroxidation in mouse liver, spleen and brain after whole-body X-ray irradiation

International Nuclear Information System (INIS)

Seino, Noritaka

1995-01-01

To investigate the radioprotective effect of dipyridamole in the aging mouse, the lipid peroxide content in aging mouse liver, spleen and brain irradiated by X-ray were measured both before and after injection of dipyridamole. The lipid peroxide content increased with aging from 2 months old to 16 months old in the mouse liver, spleen and brain. The content of lipid peroxide in the liver and spleen of the aging mouse was significantly increased in 7 days after whole-body irradiation with 8 Gy, but was unchanged in the brain. Dipyridamole, given before irradiation, significantly inhibited the increase of lipid peroxide after irradiation. These results suggest that dipyridamole may have radioprotective effects on aging mouse liver and spleen as well as on young mouse, and that inhibition of lipid peroxidation is a possible factor in the radioprotective effect of dipyridamole. (author)

Mechanism underlying the absence of ischemic changes on the exercise electrocardiogram in patients with abnormal exercise thallium-201 imaging and coronary artery disease

International Nuclear Information System (INIS)

Coplan, N.L.; Horowitz, S.F.; Hoffman, D.P.; Goldman, M.E.; Machac, J.

1985-01-01

Patients with coronary artery disease may have reversible abnormalities on a thallium myocardial perfusion study without simultaneous ischemic changes on the exercise electrocardiogram, but the mechanisms responsible for this disparity have not been fully elucidated. A group of 37 patients with angiographically demonstrated coronary artery disease and abnormal thallium perfusion imaging were divided into two groups on the basis of their exercise electrocardiographic ST segment response. Thirteen patients (Group A) had no significant electrocardiographic changes with exercise, while 24 patients (Group B) had ST changes consistent with ischemia during the test. There were no significant differences in clinical or angiographic characteristics between the two groups. Stress test results showed a similar mean duration of exercise in the two groups, but the patients in Group A achieved a significantly lower mean maximal heart rate and mean maximal double product. These results suggest that exercise thallium-electrocardiogram discordance is mediated by the level of myocardial workload achieved. An abnormal perfusion scan accompanying an exercise electrocardiogram which does not demonstrate any ischemic ST change may occur when there is sufficient increase in myocardial oxygen demand to result in differential augmentation of myocardial blood flow, but insufficient imbalance of supply and demand to result in signs of ischemia on the surface electrocardiogram

Diagnosis of coronary stenosis using thallium-201 myocardial emission computed tomography

International Nuclear Information System (INIS)

Ito, Tsunaaki; Takeda, Hiroshi; Maeda, Hisato; Nakagawa, Tsuyoshi; Yamaguchi, Nobuo; Makino, Katsutoshi; Futagami, Yasuo; Konishi, Tokuji

1985-01-01

Thallium-201 myocardial emission computed tomography (ECT) was described with respect to methods of correcting ECT data and reconstructing the images, qualitative and quantitative diagnosis in the detection of coronary stenosis. Although 201 Tl myocardial ECT (using circumferential profile method combined with washout method) has relatively high diagnostic sensitivity, the correction of absorption is not satisfactory yet. Inside absorption coefficient is considered uniform by regarding the human body as oval shape. However, the chest, including the heart, lungs, vertebrae and thoracic wall, has four different absorption coefficients. If absorption can be corrected accurately, it will be possible to completely assess the myocardial blood flow by measuring the regional myocardial uptake of thallium-201. (Namekawa, K.)

The Role of Preoperative Imaging in the Management of Nonsyndromic Lambdoid Craniosynostosis.

Science.gov (United States)

Ranganathan, Kavitha; Rampazzo, Antonio; Hashmi, Asra; Muraszko, Karin; Strahle, Jennifer; Vercler, Christian J; Buchman, Steven R

2018-01-01

The necessity of imaging for patients with craniosynostosis is controversial. Lambdoid synostosis is known to be associated with additional anomalies, but the role of imaging in this setting has not been established. The purpose of this study was to evaluate the impact of preoperative imaging on intraoperative and postoperative management among patients undergoing operative intervention for lambdoid craniosynostosis. A retrospective review of patients undergoing cranial vault remodeling for lambdoid craniosynostosis between January 2006 and 2014 was conducted. Patient demographics, age at computed tomography scan, age at surgery, results of the radiologic evaluation, operative technique, and modification of the diagnosis following the radiologic studies were analyzed. A pediatric neuroradiology and the surgical team interpreted the radiographs. The primary outcome was change in intraoperative or postoperative management based on imaging results. A total of 11 patients were diagnosed with lambdoid synostosis. Of these patients, 81.8% had abnormalities on imaging relevant to operative planning. The most common anomalies were Chiari I malformation (45%) and venous anomalies of the posterior fossa (36%). Preoperative imaging altered the management of 9 (81.8%) patients. Closer follow-up was required for 6 patients (54%). Suboccipital decompression was performed in 4 patients (36%). Venous anomalies were found in 4 patients (36%). The diagnosis was changed from positional plagiocephaly to lambdoid synostosis in 2 patients (18%). Given the frequency and significance of radiographic abnormalities in the setting of lamboid synostosis, preoperative imaging should be considered during the operative planning phase as it can affect postoperative and intraoperative management.

Effect of hypoxia on thallium kinetics in cultured chick myocardial cells

International Nuclear Information System (INIS)

Friedman, B.J.; Beihn, R.; Friedman, J.P.

1987-01-01

To assess the effect of hypoxia on cellular thallium-201 ( 201 Tl) uptake and washout independent of coronary flow, we studied thallium kinetics during normoxia and hypoxia in cultured chick ventricular cells. Monolayers of contracting ventricular cells grown on coverslips were placed in a chamber and perfused to asymptote with media containing 201 Tl. Perfusates were equilibrated with 5% CO 2 -95% air or 5% CO 2 -95% nitrogen for normoxia and hypoxia, respectively. Washout thallium kinetics were then observed during perfusion with unlabeled media. Twenty paired experiments were performed, randomly alternating the sequence of normoxia and hypoxia. Pharmacokinetics for thallium were determined by computer using standard formulae. Thallium uptake and washout were best described by assuming that intracellular thallium was contained within a single compartment. Cellular thallium uptake, as well as transfer rate constants for thallium uptake and for thallium washout during normoxia and hypoxia, were compared using paired t-tests. During normoxia and hypoxia, respectively, thallium uptake was 22 +/- 7% and 19 +/- 7% of asymptote (p less than 0.01); the compartmental rate constant for uptake by the cell was 0.16 +/- 0.07 min-1 and 0.15 +/- 0.06 min-1 (N.S.); and the transfer rate constant for washout from the cell was 0.26 +/- 0.06 min-1 and 0.23 +/- 0.05 min-1 (p less than 0.01). We conclude that there was a small (14%) decrease in thallium uptake during hypoxia. The rate of thallium uptake and washout was slightly less during hypoxia, although only the rate of washout was significantly less. These data show that cellular accumulation of thallium and the rate of washout of thallium were minimally decreased by hypoxia independent of blood flow

Aspirin and extended-release dipyridamole versus clopidogrel for recurrent stroke

DEFF Research Database (Denmark)

Sacco, Ralph L; Diener, Hans-Christoph; Yusuf, Salim

2008-01-01

BACKGROUND: Recurrent stroke is a frequent, disabling event after ischemic stroke. This study compared the efficacy and safety of two antiplatelet regimens--aspirin plus extended-release dipyridamole (ASA-ERDP) versus clopidogrel. METHODS: In this double-blind, 2-by-2 factorial trial, we randomly...

201Tl-99mTc subtraction scintigraphy as a preoperative localization procedure for persistent primary and secondary hyperparathyroidism

International Nuclear Information System (INIS)

Geipel, D.; Mischke, W.; Deckart, H.; Weiss, M.L.

1989-01-01

5 patients with a persistent hyperparathyroidism underwent thallium-technetium subtraction scintigraphy prior to reoperation. In all cases the fidings obtained by scintigraphy were confirmed by operation. Based on the preoperative localization of parathyroid adenomas and hyperplastic parathyroid bodies, respectively, their extirpation could be performed in short time. This new nuclear medicine localization procedure for identifying hyperparathyroidism has proved to be useful both in the cervical region and the mediastinum. Thus, as a sensitive method with a non-invasive character this procedure should be applied to reoperations before any other localization method. The indication for performing thallium-technetium subtraction scintigraphy as well as its evaluation have to be carried out in close collaboration between surgeons and nuclear medicine specialists. (author)

Predicting the extent and location of coronary artery disease during the early postinfarction period by quantitative thallium-201 scintigraphy

International Nuclear Information System (INIS)

Gibson, R.S.; Taylor, G.J.; Watson, D.D.; Stebbins, P.T.; Martin, R.P.; Crampton, R.S.; Beller, G.A.

1981-01-01

The ability of quantitative thallium-201 scintigraphy to predict the extent and location of coronary artery disease before hospital discharge after acute myocardial infarction was evaluated in 52 patients. All patients underwent coronary angiography and serial thallium-201 imaging either at rest or after submaximal exercise stress. Two or three vessel disease was designated if abnormal thallium-201 uptake or washout patterns, or both, were seen in two or three vascular segments, respectively. Of 156 vessels analyzed in the 52 patients, 91 stenoses of 70 percent or greater were found by angiography. Seventy-four of these were predicted by scintigraphy. The specificity of scintigraphy for identifying vessel stenoses was 92 percent. Sensitivity for detecting and localizing stenoses supplying an infarct zone was 96 percent compared with 62 percent for stenoses supplying myocardium remote from the acute infarct. Perfusion abnormalities were more frequently seen in the distribution of vessels with severe stenoses than in those with moderate stenoses. Scintigraphy detected a greater proportion of left anterior descending and right coronary arterial stenoses than circumflex stenoses. In the 42 patients who underwent submaximal exercise testing, multivariate analysis of 23 clinical and laboratory variables identified multiple thallium-201 defects as the best predictor of multivessel disease. The predictive accuracy of exercise-induced S-T segment depression was only 45 percent compared with 88 percent for thallium-201 scintigraphy. Thallium-201 imaging at rest is reliable in assessing the extent of coronary disease in hospitalized patients who cannot undergo exercise testing because of unstable angina, uncompensated heart failure, poorly controlled arrhythmias or physical limitations

Head-to-head comparison of dipyridamole, dobutamine and pacing stress echocardiography for the detection of myocardial ischemia in an animal model of coronary artery stenosis

Directory of Open Access Journals (Sweden)

A. Schmidt

2001-07-01

Full Text Available To compare the sensitivity of dipyridamole, dobutamine and pacing stress echocardiography for the detection of myocardial ischemia we produced a physiologically significant stenosis in the left circumflex artery of 14 open-chest dogs (range: 50 to 89% reduction in luminal diameter. In each study, dobutamine (5 to 40 µg kg-1 min-1 in 3-min stages and pacing (20 bpm increments, each 2 min, up to 260 bpm were performed randomly, and then followed by dipyridamole (up to 0.84 mg/kg over 10 min. The positivity of stress echocardiography tests was quantitatively determined by a significant (P<0.05 reduction of or failure to increase absolute and percent systolic wall thickening in the stenotic artery supplied wall, as compared to the opposite wall (areas related to the left anterior descending artery. Systolic and diastolic frozen images were analyzed off-line by two blinded observers in the control and stress conditions. The results showed that 1 the sensitivity of dobutamine, dipyridamole and pacing stress tests was 57, 57 and 36%, respectively; 2 in animals with positive tests, the mean percent change of wall thickening in left ventricular ischemic segments was larger in the pacing (-19 ± 11% and dipyridamole (-18 ± 16% tests as compared to dobutamine (-9 ± 6% (P = 0.05, but a similar mean reduction of wall thickening was observed when this variable was normalized to a control left ventricular segment (area related to the left anterior descending artery (pacing: -16 ± 7%; dipyridamole: -25 ± 16%; dobutamine: -26 ± 10%; not significant, and 3 a significant correlation was observed between magnitude of coronary stenosis and left ventricular segmental dysfunction induced by ischemia in dogs submitted to positive stress tests. We conclude that the dobutamine and dipyridamole stress tests showed identical sensitivities for the detection of myocardial ischemia in this one-vessel disease animal model with a wide range of left circumflex artery

Stress magnetic resonance imaging in coronary artery disease. 11

International Nuclear Information System (INIS)

Pennell, D.J.; Underwood, S.R.

1991-01-01

The feasibility of MRI of wall motion and cardiovascular haemodynamics has been investigated during pharmacological stress with dipyridamole and dobutamine as pharmacological stressors. The authors conclude that dobutamine is preferable to dipyridamole for inducing myocardial ischemia during imaging. (H.W.). 74 refs.; 8 figs.; 5 tabs

Effect of preoperative antiplatelet drugs on vascular prostacyclin synthesis.

Science.gov (United States)

Karwande, S V; Weksler, B B; Gay, W A; Subramanian, V A

1987-03-01

Patients undergoing aortocoronary bypass using autogenous saphenous veins were randomly divided into three comparable groups. Group 1 (n = 10) acted as a control, Group 2 (n = 14) received 80 mg of aspirin at midnight before the operation, and Group 3 (n = 12) received 80 mg of aspirin and 75 mg of dipyridamole at midnight and an additional 75-mg dose of dipyridamole at 6 AM. The purpose was to determine which regimen would maximally inhibit platelet function without depressing vascular prostacyclin synthesis. Serum thromboxane A2, saphenous vein wall and aortic wall prostacyclin, platelet aggregation, and bleeding time were measured in all patients. None was restarted on a regimen of aspirin or dipyridamole postoperatively. Aspirin alone and in combination with dipyridamole significantly inhibited thromboxane A2 and platelet aggregation in all treated patients but spared venous prostacyclin synthesis. Aortic prostacyclin synthesis was partially inhibited in both treated groups. Chest tube drainage was comparable in all three groups. These results indicate that the combination of aspirin and dipyridamole offers no measurable advantage over aspirin alone in the perioperative period.

Evaluation of myocardial and skeletal muscular involvement with thallium-201 myocardial emission computed tomography and whole body scintigraphy

International Nuclear Information System (INIS)

Yamamoto, Shuhei; Matsushima, Hideo; Sotobata, Iwao; Suzuki, Akio; Indo, Toshikatsu; Matsuoka, Yukihiko

1986-01-01

Thallium-201 (Tl-201) myocardial emission computed tomography and whole body scintigraphy were performed using a rotating gamma camera in 64 patients with neurologic disease and 14 normal subjects. Thallium-201 myocardial perfusion defects were seen in 40 % of the muscular involvement in 47 patients with muscular dystrophy (MD), in whom morphological abnormality of the heart was common. There was strong relationship between the degree of left ventricular perfusion defects and the degree of pulmonary uptake of Tl-201. Thallium-201 whole body scintigraphy showed homogeneous distribution of Tl-201 in the extremities in normal subjects, and perfusion defects in 73 % of the muscular lesions in MD patients. Muscular and skeletal lesions for MD appear to progress independently. Thallium-201 imaging seems to be of clinical value in assessing the muscular and skeletal lesions. (Namekawa, K.)

AIDS-related Kaposi sarcoma: findings on thallium-201 scintigraphy

International Nuclear Information System (INIS)

Lee, V.W.; Rosen, M.P.; Baum, A.; Cohen, S.E.; Cooley, T.P.; Liebman, H.A.

1988-01-01

No simple, noninvasive method is available for evaluating extracutaneous Kaposi sarcoma in AIDS patients or for following the tumor's response to treatment. We report our preliminary experience with thallium-201 scintigraphy in nine AIDS patients with proved Kaposi sarcoma. Eight of the nine had abnormal uptake of the radionuclide in skin, lymph nodes, oral cavity, vagina, and lungs. Only four of the nine had cutaneous Kaposi sarcoma at the time of scanning. All cutaneous and mucosal lesions were thallium avid. Two of the six patients with thallium-avid nodes underwent nodal biopsy. Both biopsies confirmed the diagnosis of Kaposi sarcoma. Cutaneous Kaposi sarcoma developed later in one of these patients, showing the efficacy of thallium scintigraphy for the early detection of extracutaneous lesions. These preliminary results show thallium avidity in Kaposi sarcoma involving the skin and various extracutaneous sites (lymph nodes, lung, mucosa, and vagina). Thallium scintigraphy is a potentially useful procedure for detecting extracutaneous Kaposi sarcoma in AIDS patients

Comparison of exercise radionuclide angiography with thallium SPECT imaging for detection of significant narrowing of the left circumflex coronary artery

International Nuclear Information System (INIS)

Dilsizian, V.; Perrone-Filardi, P.; Cannon, R.O. III; Freedman, N.M.; Bacharach, S.L.; Bonow, R.O.

1991-01-01

Although quantitation of exercise thallium tomograms has enhanced the noninvasive diagnosis and localization of coronary artery disease, the detection of stenosis of the left circumflex coronary artery remains suboptimal. Because posterolateral regional wall motion during exercise is well assessed by radionuclide angiography, this study determined whether regional dysfunction of the posterolateral wall during exercise radionuclide angiography is more sensitive in identifying left circumflex disease than thallium perfusion abnormalities assessed by single-photon emission computed tomography (SPECT). One hundred ten consecutive patients with CAD were studied, of whom 70 had a significant stenosis of the left circumflex coronary artery or a major obtuse marginal branch. Both regional function and segmental thallium activity of the posterolateral wall were assessed using visual and quantitative analysis. Left ventricular regional function was assessed objectively by dividing the left ventricular region of interest into 20 sectors; the 8 sectors corresponding to the posterolateral free wall were used to assess function in the left circumflex artery distribution. Similarly, using circumferential profile analysis of short-axis thallium tomograms, left ventricular myocardial activity was subdivided into 64 sectors; the 16 sectors corresponding to the posterolateral region were used to assess thallium perfusion abnormalities in the left circumflex artery territory. Qualitative posterolateral wall motion analysis detected 76% of patients with left circumflex coronary artery stenosis, with a specificity of 83%, compared with only 44% by qualitative thallium tomography (p less than 0.001) and a specificity of 92%

American Thyroid Association statement on preoperative imaging for thyroid cancer surgery.

Science.gov (United States)

Yeh, Michael W; Bauer, Andrew J; Bernet, Victor A; Ferris, Robert L; Loevner, Laurie A; Mandel, Susan J; Orloff, Lisa A; Randolph, Gregory W; Steward, David L

2015-01-01

The success of surgery for thyroid cancer hinges on thorough and accurate preoperative imaging, which enables complete clearance of the primary tumor and affected lymph node compartments. This working group was charged by the Surgical Affairs Committee of the American Thyroid Association to examine the available literature and to review the most appropriate imaging studies for the planning of initial and revision surgery for thyroid cancer. Ultrasound remains the most important imaging modality in the evaluation of thyroid cancer, and should be used routinely to assess both the primary tumor and all associated cervical lymph node basins preoperatively. Positive lymph nodes may be distinguished from normal nodes based upon size, shape, echogenicity, hypervascularity, loss of hilar architecture, and the presence of calcifications. Ultrasound-guided fine-needle aspiration of suspicious lymph nodes may be useful in guiding the extent of surgery. Cross-sectional imaging (computed tomography with contrast or magnetic resonance imaging) may be considered in select circumstances to better characterize tumor invasion and bulky, inferiorly located, or posteriorly located lymph nodes, or when ultrasound expertise is not available. The above recommendations are applicable to both initial and revision surgery. Functional imaging with positron emission tomography (PET) or PET-CT may be helpful in cases of recurrent cancer with positive tumor markers and negative anatomic imaging.

Clinical application of bull's eye map in 201Tl myocardial tomography for the diagnosis of coronary artery disease

International Nuclear Information System (INIS)

Liu Yongchang

1991-01-01

Bull's eye map in thallium-201 myocardial tomography was performed in 50 patients, and compared with planar imaging. In 27 rest imaging, 6 AMI were abnormal both in plannar and bull's eye images, in 10 OMI, planar abnormal in 6 and doubtful in 4, while bull's eye abnormal in 8 and doubtful in 2; in 11 angina, planar abnormal in 2, doubtful in 5 and normal in 4; but bull's eye abnormal in 5, doubtful abnormal in 4 and normal in 2. In 3 cases of dipyridamole imaging 2 angina were positive, 1 hypertension was negetive, while bull's eye map were all positive. It was demonstrated that bull's eye map gives a direct and clean view and also easy for the anatomical localization of the hypoperfused area

Isolation of radioactive thallium from mercury targets

International Nuclear Information System (INIS)

Sevast'yanova, A.S.; Kozlova, M.D.; Malinin, A.B.; Kurenkov, N.V.

1989-01-01

The extraction method of thallium-201, 202, 200 separation from mercury target irradiated by protons is suggested. Tl + in sulfuric acid solution prepared after Hg-target treatment with the sulfuric acid was oxidized up to Tl 3+ with hydrogen peroxide and then it was extracted with butylacetate. Thallium was re-exrtacted by the sulfurous acid solution in the presence of CCl 4 , and Tl 3+ was recovered up to Tl + . The method permits to separate thallium with chemical yield nor less than 95 %. 2 refs

Extracorporeal treatment for thallium poisoning

DEFF Research Database (Denmark)

Ghannoum, Marc; Nolin, Thomas D; Goldfarb, David S

2012-01-01

The EXtracorporeal TReatments In Poisoning (EXTRIP) workgroup was formed to provide recommendations on the use of extracorporeal treatment (ECTR) in poisoning. To test and validate its methods, the workgroup reviewed data for thallium (Tl).......The EXtracorporeal TReatments In Poisoning (EXTRIP) workgroup was formed to provide recommendations on the use of extracorporeal treatment (ECTR) in poisoning. To test and validate its methods, the workgroup reviewed data for thallium (Tl)....

Tomographic myocardial perfusion scintigraphy in children with Kawasaki disease

International Nuclear Information System (INIS)

Spielmann, R.P.; Nienaber, C.A.; Hausdorf, G.; Montz, R.

1987-01-01

Myocardial infarction and stenotic coronary lesions are serious late complications in children with Kawasaki disease. For the noninvasive assessment of myocardial perfusion, dipyridamole-redistribution 201 Tl emission computed tomography (ECT) was performed in seven children (age 2 8/12-8 7/12 yr) 3-20 mo after the acute stage of the disease. In all patients, coronary aneurysms had been demonstrated by cross-sectional echocardiography. The scintigrams of six children showed no significant regional reduction of myocardial thallium uptake. These children had remained asymptomatic since the acute stage of Kawasaki disease. Persistent and transient thallium defects were present in one child with documented myocardial infarction. For this patient, obstruction of corresponding coronary vessels was confirmed by contrast angiography. It is suggested, that 201 Tl ECT after dipyridamole-induced vasodilation may be used as a safe alternative to invasive coronary angiography for follow-up investigations in patients with Kawasaki disease

{sup 201}Thallium SPECT, accuracy in astrocytoma diagnosis and treatment evaluation

Energy Technology Data Exchange (ETDEWEB)

Kaellen, K

1999-10-01

The aims of the studies included in this thesis were: - to investigate the reliability of {sup 201}Thallium single photon emission computed tomography. Tl SPECT for preoperative diagnosis and histological staging of malignant astrocytomas in comparison with CT; - to develop a method for quantification of cerebral thallium uptake, and to evaluate the quantitative measurement in comparison with CT, for astrocytoma treatment follow-up purposes; - to compare quantitative Tl SPECT and proton magnetic resonance spectroscopy (H-MRS) with conventional MR imagingfor astrocytoma monitoring, and to evaluate associations between change of morphological tumour characteristics during treatment and changes of cerebral thallium uptake and metabolic ratios. Results and conclusions: - High TI-index, calculated as a ratio comparing tumour uptake to uptake in the contralateral hemisphere, is an indicator of highly malignant astrocytoma. Differentiation between the high-grade astrocytomas, the low-grade astrocytomas, and infectious lesions is only partial, with an overlap of Tl-indexes between these groups. High-grade astrocytomas that do not show contrast enhancement on CT, and astrocytomas with central necrosis and moderate ring-enhancement, tend to be underestimated when evaluated by Tl-index calculation. Tl SPECT is not a reliable method for non-invasive tumour staging among the group of highly malignant astrocytomas. - Quantification of cerebral TI-uptake, defining the volume of viable tumour tissue, is a new method for astrocytoma chemotherapy monitoring. Results suggest that the method provides prognostic information, and information of treatment efficacy, at an earlier stage than CT. - We did not find a higher accuracy of quantitative Tl SPECT than of MR for monitoring purposes and our results indicated that treatment induced MR changes were interrelated with TI-uptake variations. - Multi-voxel H-MRS was difficult to apply for astrocytoma treatment monitoring, due to the

Commercial production of thallium-201 chloride

International Nuclear Information System (INIS)

Sokolov, S.V.; Volkova, N.M.; Skokov, V.S.

1989-01-01

Thallium-201 chloride pharmaceuticals production practice at the Medradiopreparat factory under USSR Ministry of Public Health is described. The factory is carried out series-produced supplies of the compound prepared according to a new practice from September, 1985. Thallium-201 extraction from cyclotron targets irradiated is carried out by the extraction method

[Thallium poisoning which stimulated systemic lupus erythematosus in a child].

Science.gov (United States)

Montoya-Cabrera, M A; Sauceda-García, J M; Escalante-Galindo, P; López-Morales, E

1991-01-01

We report the case of a preschool boy who, without knowledge of his relatives, ingested thallium sulfate in a dose calculated in 30 mg/kg. He presented a systemic lupus erythematosus-like syndrome and only further alopecia oriented the diagnosis of thallium toxicosis; thallium blood levels were; 37.2 micrograms/dl and in urine: 2330 micrograms/L. Treatment with the chelating agent D. penicillamine was effective, the clinical picture disappeared and the decrease of the thallium levels was observed. Thallium intoxication should be considered in the differential diagnosis of connective tissue disease as the above mentioned.

Technetium 99m SESTAMIBI myocardial perfusion imaging: Comparison between treadmill, dipyridamole and trans-oesophageal atrial pacing 'stress' tests in normal subjects

International Nuclear Information System (INIS)

Primeau, M.; Taillefer, R.; Lambert, R.; Essiambre, R.; Honos, G.

1991-01-01

The purpose of this study was to determine the blood clearance, myocardial uptake and heart/lung and heart/liver ratios of technetium 99m methoxyisobutylisonitrile ( 99m Tc-SESTAMIBI) following 3 different types of cardiac stimulation in normal subjects: Treadmill stress (STRESS), intravenous administration of dipyridamole (DIP) and trans-oesophageal atrial pacing (TAP). Ten normal volunteers were submitted to 3 injections of 99m Tc-SESTAMIBI (10 mCi/70 kg, separated by an interval of 7 days) following STRESS (standard Bruce protocol), DIP (0.142 mg/kg.min during 4 min) and TAP procedures. Blood samples were collected from 1 to 60 min after each 99m Tc-SESTAMIBI injection. Planar imaging was performed at 5, 30 and 60 min. Blood retention (percentage of injected dose at 1 min) was 56%±4%, 24%±4% and 38%±6% for STRESS, DIP and TAP, respectively (P 99m Tc-SESTAMIBI. (orig.)

Correction for patient and organ movement in SPECT: application to exercise thallium-201 cardiac imaging

International Nuclear Information System (INIS)

Geckle, W.J.; Frank, T.L.; Links, J.M.; Becker, L.C.

1988-01-01

We describe a technique for correction of artifacts in exercise 201 Tl single photon emission computed tomography (SPECT) images arising from abrupt or gradual translational movement of the heart during acquisition. The procedure involves the tracking of the center of the heart in serial projection images using an algorithm which we call diverging squares. Each projection image is then realigned in the x-y plane so that the heart center conforms to the projected position of a fixed point in space. The shifted projections are reconstructed using the normal filtered backprojection algorithm. In validation studies, the motion correction procedure successfully eliminated movement artifacts in a heart phantom. Image quality was also improved in over one-half of 36 exercise thallium patient studies. The corrected images had smoother and more continuous left ventricular walls, greater clarity of the left ventricular cavity, and reduced streak artifacts. Rest injected or redistribution images, however, were often made worse, due to reduced heart to liver activity ratios and poor tracking of the heart center. Analysis of curves of heart position versus projection angle suggests that translation of the heart is common during imaging after exercise, and results from both abrupt patient movements, and a gradual upward shift of the heart. Our motion correction technique appears to represent a promising new approach for elimination of movement artifacts and enhancement of resolution in exercise 201 Tl cardiac SPECT images

Nanosized f.c.c. thallium inclusions in aluminium

International Nuclear Information System (INIS)

Johnson, E.; Johansen, A.; Thoft, N.B.; Andersen, H.H.; Sarholt-Kristensen, L.

1993-01-01

Ion implantation of pure aluminium with thallium induces the formation of nanosized crystalline inclusions of thallium with a f.c.c. structure. The size of the inclusions depends on the implantation conditions and subsequent annealing treatments and is typically in the range from 1 to 10 nm. The inclusions are aligned topotactically with the aluminium matrix with a cube-cube orientation relationship and they have a truncated octahedral shape bounded by {111} and {001} planes. The lattice parameter of the f.c.c. thallium inclusions is 0.484 ± 0.002 nm, which is slightly but significantly larger than in the high-pressure f.c.c. thallium phase known to be stable above 3.8 GPa. (Author)

A method for the production of thallium-201

International Nuclear Information System (INIS)

Ageev, V.A.; Kljuchnikov, A.A.; Linev, A.F.; Khalkin, V.A.; Zaitseva, N.G.

1987-01-01

For the production of thallium-201 a target of at least 95% enriched pure lead-206 is irradiated by a proton beam of an energy of between 50 and 70 MeV. During irradiation the reaction 206 Pb(p,6n) 201 Bi takes place. The target is kept sufficiently long for the transition 201 Bi- 201 Pb- 201 Tl to take place. The target is then dissolved in acid. The thallium-201 contained in the acid is oxidized to the trivalent state followed by precipitation of the lead. Lead traces remaining in solution are separated from the thallium-201 through cation exchange following which the thallium-201 is eluted using hydrochloric acid

Diagnostic yield of preoperative computed tomography imaging and the importance of a clinical decision for lung cancer surgery

International Nuclear Information System (INIS)

Sato, Shuichi; Koike, Teruaki; Yamato, Yasushi

2010-01-01

This study aimed to evaluate the diagnostic yield of preoperative computed tomography (CT) imaging and the validity of surgical intervention based on the clinical decision to perform surgery for lung cancer or suspected lung cancer. We retrospectively evaluated 1755 patients who had undergone pulmonary resection for lung cancer or suspected lung cancer. CT scans were performed on all patients. Surgical intervention to diagnose and treat was based on a medical staff conference evaluation for the suspected lung cancer patients who were pathologically undiagnosed. We evaluated the relation between resected specimens and preoperative CT imaging in detail. A total of 1289 patients were diagnosed with lung cancer by preoperative pathology examination; another 466 were not pathologically diagnosed preoperatively. Among the 1289 patients preoperatively diagnosed with lung cancer, the diagnoses were confirmed postoperatively in 1282. Among the 466 patients preoperatively undiagnosed, 435 were definitively diagnosed with lung cancer, and there were 383 p-stage I disease patients. There were 38 noncancerous patients who underwent surgery with a diagnosis of confirmed or suspected lung cancer. Among the 1755 patients who underwent surgery, 1717 were pathologically confirmed with lung cancer, and the diagnostic yield of preoperative CT imaging was 97.8%. Among the 466 patients who were preoperatively undiagnosed, 435 were compatible with the predicted findings of lung cancer. Diagnostic yields of preoperative CT imaging based on clinical evaluation are sufficiently reliable. Diagnostic surgical intervention was acceptable when the clinical probability of malignancy was high and the malignancy was pathologically undiagnosed. (author)

Changes of electrocardiogram and hemodynamics in response to dipyridamole: In vivo comparative analyses using anesthetized beagle dogs and microminipigs.

Science.gov (United States)

Ando, Kentaro; Takahara, Akira; Nakamura, Yuji; Wada, Takeshi; Chiba, Koki; Goto, Ai; Lubna, Nur Jaharat; Hagiwara-Nagasawa, Mihoko; Izumi-Nakaseko, Hiroko; Hoshiai, Kiyotaka; Akie, Yasuki; Naito, Atsuhiko T; Sugiyama, Atsushi

2018-02-01

Microminipigs are expected as a novel animal model for cardiovascular pharmacological experiments. Since inherent vulnerability of coronary circulation of microminipigs has not been characterized, we performed dipyridamole-stress test to both microminipigs and beagle dogs, and compared the results. Dipyridamole in doses of 0.056 and 0.56 mg/kg were intravenously infused over 10 min (n = 4 for each animal). Dipyridamole decreased the systolic/diastolic blood pressures and double product in dogs as well as in microminipigs; but it did not significantly alter the heart rate or the global balance between the myocardial oxygen demand and supply in either animal. While organic coronary arterial stenosis was not detected in either animal, dogs have well-developed epicardial intracoronary networks unlike microminipigs. Like in humans, dipyridamole did not affect the ST segment of microminipigs, whereas it substantially depressed that in dogs. The results indicate the onset of subendocardial ischemia by dipyridamole in dogs may be partly associated with their well-developed native coronary collateral channels. Microminipigs would be more useful to evaluate the drugs which may affect the coronary circulation in the pre-clinical study than dogs. Copyright © 2018 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Position tracking of moving liver lesion based on real-time registration between 2D ultrasound and 3D preoperative images

International Nuclear Information System (INIS)

Weon, Chijun; Hyun Nam, Woo; Lee, Duhgoon; Ra, Jong Beom; Lee, Jae Young

2015-01-01

Purpose: Registration between 2D ultrasound (US) and 3D preoperative magnetic resonance (MR) (or computed tomography, CT) images has been studied recently for US-guided intervention. However, the existing techniques have some limits, either in the registration speed or the performance. The purpose of this work is to develop a real-time and fully automatic registration system between two intermodal images of the liver, and subsequently an indirect lesion positioning/tracking algorithm based on the registration result, for image-guided interventions. Methods: The proposed position tracking system consists of three stages. In the preoperative stage, the authors acquire several 3D preoperative MR (or CT) images at different respiratory phases. Based on the transformations obtained from nonrigid registration of the acquired 3D images, they then generate a 4D preoperative image along the respiratory phase. In the intraoperative preparatory stage, they properly attach a 3D US transducer to the patient’s body and fix its pose using a holding mechanism. They then acquire a couple of respiratory-controlled 3D US images. Via the rigid registration of these US images to the 3D preoperative images in the 4D image, the pose information of the fixed-pose 3D US transducer is determined with respect to the preoperative image coordinates. As feature(s) to use for the rigid registration, they may choose either internal liver vessels or the inferior vena cava. Since the latter is especially useful in patients with a diffuse liver disease, the authors newly propose using it. In the intraoperative real-time stage, they acquire 2D US images in real-time from the fixed-pose transducer. For each US image, they select candidates for its corresponding 2D preoperative slice from the 4D preoperative MR (or CT) image, based on the predetermined pose information of the transducer. The correct corresponding image is then found among those candidates via real-time 2D registration based on a

Isoproterenol stress thallium scintigraphy for detecting coronary artery disease

International Nuclear Information System (INIS)

Watanabe, Shigeyuki; Ajisaka, Ryuichi; Masuoka, Takeshi; Iida, Kaname; Sugishita, Yasuro; Ito, Iwao; Takeda, Tohru; Toyama, Hinako; Akisada, Masayoshi

1989-01-01

The present study was undertaken to assess the diagnostic value of isoproterenol (ISP) thallium scintigraphy. The findings were compared with those of ISP-ECG and exercise thallium scintigraphy. The study population consisted of 24 patients who had a history of chest pain without previous myocardial infarction. ISP was given at increasing doses of 0.02, 0.04, 0.08 μg/mg/min at 3-minutes intervals, and was terminated for any of the following reasons: angina, significant arrhythmia, significant ST segment depression, or target heart rate. Thallium scintigrams were obtained immediately after terminating ISP infusion, and after a 3-hour delay, redistribution scans were obtained. Scintigrams were considered positive when a reversible defect was present. After stress tests, coronary angiography was performed. According to the presence or absence of significant coronary artery stenosis, the patients were divided into coronary artery disease (CAD) group (n=12) and so-called normal coronary (NC) group (n=12). Among 12 patients in the CAD group, ISP induced anginal pain in six (50%), and ISP-ECT and ISP thallium scintigraphy were positive in 10 (83%) and in 11 (92%), compared with four(33%), four(33%) and two (17%) in the NC group. These data indicate that ISP-ECG had a sensitivity of 83%, a specificity of 67%, and a diagnostic accuracy of 75%; and the corresponding figures for ISP thallium scintigraphy were 92%, 83%, and 88%. Among nine patients who underwent both ISP thallium scintgraphy and exercise thallium scintigraphy, all patients, except for one false negative case on ISP thallium scintigraphy, were correctly diagnosed. No serious complications occurred in association with the ISP infusion test. ISP thallium scintigraphy was considered to be a safe, sensitive, and specific method for diagnosing CAD when exercise tests were intolerable. (N.K.)

Anhydrous thallium hydrogen L-glutamate: polymer networks formed by sandwich layers of oxygen-coordinated thallium ions cores shielded by hydrogen L-glutamate counterions.

Science.gov (United States)

Bodner, Thomas; Wirnsberger, Bianca; Albering, Jörg; Wiesbrock, Frank

2011-11-07

Anhydrous thallium hydrogen L-glutamate [Tl(L-GluH)] crystallizes from water (space group P2(1)) with a layer structure in which the thallium ions are penta- and hexacoordinated exclusively by the oxygen atoms of the γ-carboxylate group of the hydrogen L-glutamate anions to form a two-dimensional coordination polymer. The thallium-oxygen layer is composed of Tl(2)O(2) and TlCO(2) quadrangles and is only 3 Å high. Only one hemisphere of the thallium ions participates in coordination, indicative of the presence of the 6s(2) lone pair of electrons. The thallium-oxygen assemblies are shielded by the hydrogen l-glutamate anions. Only the carbon atom of the α-carboxylate group deviates from the plane spanned by the thallium ions, the γ-carboxylate groups and the proton bearing carbon atoms, which are in trans conformation. Given the abundance of L-glutamic and L-aspartic acid in biological systems on the one hand and the high toxicity of thallium on the other hand, it is worth mentioning that the dominant structural motifs in the crystal structure of [Tl(L-GluH)] strongly resemble their corresponding analogues in the crystalline phase of [K(L-AspH)(H(2)O)(2)].

Scintigraphic visualization of myocardial infarcts in baboons using thallium-201 and technetium-99m pyrophosphate

Energy Technology Data Exchange (ETDEWEB)

Frick, M P; Ponto, R A; Pyle, R B; Yasmineh, W G; Loken, M K

1978-01-01

Four baboons with myocardial infarcts were evaluated using thallium-201 for myocardial imaging and /sup 99m/Tc pyrophosphate for infarct visualization. Scintiphotographic findings were compared with the size of myocardial infarcts calculated from measurements of the activity of MB isoenzymes of creatine kinase (CK-MB) in serum and in the myocardium at autopsy, as described by Sobel's method. Lack of thallium-201 accumulation was noted in left ventricular infarcts of 3 of the 4 baboons. These same areas localized /sup 99m/Tc pyrophosphate administered 24 to 30 h after infarction.

Preoperative localization of epileptic foci with SPECT brain perfusion imaging, electrocorticography, surgery and pathology

International Nuclear Information System (INIS)

Jia Shaowei; Xu Wengui; Chen Hongyan; Weng Yongmei; Yang Pinghua

2002-01-01

Objective: The value of preoperative localization of epileptic foci with SPECT brain perfusion imaging was investigated. Methods: The study population consisted of 23 patients with intractable partial seizures which was difficult to control with anticonvulsant for long period. In order to preoperatively locate the epileptic foci, double SPECT brain perfusion imaging was performed during interictal and ictal stage. The foci were confirmed with electrocorticography (EcoG), surgery and pathology. Results: The author checked with EcoG the foci shown by SPECT, 23 patients had all typical spike discharge. The regions of radioactivity increase in ictal matched with the abnormal electrical activity areas that EcoG showed. The spike wave originated in the corresponding cerebrum cortex instead of hyperplastic and adherent arachnoid or tumor itself. Conclusions: SPECT brain perfusion imaging contributes to distinguishing location, size, perfusion and functioning of epileptogenic foci, and has some directive function on to making out a treatment programme at preoperation

Effect of surfactants, gastric emptying, and dosage form on supersaturation of dipyridamole in an in vitro model simulating the stomach and duodenum.

Science.gov (United States)

Mitra, A; Fadda, H M

2014-08-04

The purpose of this study was to investigate the influence of gastric emptying patterns, surfactants, and dosage form on the supersaturation of a poorly soluble weakly basic drug, dipyridamole, using an in vitro model mimicking the dynamic environment of the upper gastrointestinal tract, and, furthermore, to evaluate the usefulness of this model in establishing correlations to in vivo bioavailability for drugs with solubility/dissolution limited absorption. A simulated stomach duodenum model comprising four compartments was used to assess supersaturation and precipitation kinetics as a function of time. It integrates physiologically relevant fluid volumes, fluid transfer rates, and pH changes of the upper GI tract. Monoexponential gastric emptying patterns simulating the fasted state were compared to linear gastric emptying patterns simulating the fed state. The effect of different surfactants commonly used in oral preparations, specifically, sodium lauryl sulfate (SLS), poloxamer-188, and polysorbate-80, on dipyridamole supersaturation was investigated while maintaining surface tension of the simulated gastric fluids at physiological levels and without obtaining artificial micellar solubilization of the drug. The supersaturation behavior of different dose strengths of dipyridamole was explored. Significant levels of dipyridamole supersaturation were observed in the duodenal compartment under all the different in vivo relevant conditions explored. Dipyridamole supersaturation ratios of up to 11-fold have been observed, and supersaturation has been maintained for up to 120 min. Lower duodenal concentrations of dipyridamole were observed under linear gastric emptying patterns compared to mononexponential gastric emptying. The mean duodenal area under concentration-time curves (AUC60min) for the dipyridamole concentration profile in the duodenal compartment is significantly different for all the surfactants explored (P stomach duodenum model can provide a reliable and

The preoperative imaging evaluation for cochlear implantation

International Nuclear Information System (INIS)

Liu Zhonglin; Wang Zhenchang; Fu Lin; Li Yong; Xian Junfang; Yang Bentao; Lan Baosen; Li Yongxin; Zheng Jun; Song Yan; Liu Bo; Chen Xueqing; He Haili

2006-01-01

Objective: To analyze CT and MRI findings of temporal bone and to evaluate preoperative diagnostic value for cochlear implantation. Methods: One hundred and sixty candidates for cochlear implantation were examined with axial CT scan, 64 of them also with coronal CT scan, and 119 patients with MRI. Results: All of 320 ears were well-aerated, and 206 ears had mastoid cavities extended posteriorly to the sigmoid sinus. The length from posterior-lateral tympanic wall to the outer cortex was (2.34±0.42) mm (left side) and (2.25±0.40) mm (right side) (U=1.887, P 1 and T 2 signal on MRI. The congenital malformations of inner ear occurred in 67 ears, including complete dysplasia in 1 ear, cochlear hypodysplasia in 6 ears, Mondini deformation in 5 ears, enlarged vestibular aqueduct in 40 ears, dysplastic semicircular canal and the vestibulae in 10 ears, and narrowing of internal auditory canal in 5 ears. Conclusion: Preoperative imaging examinations can provide critical information to ensure successful cochlear' implantation. (authors)

ECG-manifest and ECG-silent dipyridamole technetium-99m sestamibi SPET perfusion defects in patients with ischaemic heart disease

International Nuclear Information System (INIS)

Galli, M.; Marcassa, C.; Bosimini, E.; Zoccarato, O.; Comazzi, F.; Giannuzzi, P.

1997-01-01

To investigate the relationship between ECG changes and perfusion abnormalities, body surface maps were recorded during dipyridamole infusion in 55 subjects (11 normals and 44 patients with ischaemic heart disease) undergoing dipyridamole technetium-99m sestamibi single-photon emission tomography (SPET). All had a normal resting ECG. The extent and severity of the sestamibi defect were quantified. New negative areas in the isointegral maps and rest-dipyridamole map differences >2 SD from normal limits were considered abnormal. After dipyridamole in normals, neither perfusion defects nor ≥1 mm ST segment depression on 12-lead ECG nor new negative areas in isointegral maps occurred. In patients, dipyridamole induced new perfusion defects in 35 (80%) but ST segment depression in only 18 (41%, P<0.001). Of the 35 patients with perfusion defects, 17 (49%, group 1) showed ST segment depression, while the other 18 (51%, group 2) did not. Abnormal body surface maps were found in 100% of group 1 and 88% of group 2 patients (NS). In group 1, the provoked hypoperfusion was of greater extent (P=0.007) and severity (P=0.01) and the onset of map abnormalities was significantly earlier (P<0.001) than in group 2; time to map abnormalities was also significantly shorter than time to ST segment depression (P=0.01). In the 35 patients with complete scintigraphic, body map and angiographic data, the severity of reversible perfusion defect proved to be the strongest correlate of ST segment depression upon logistic regression analysis. Thus, sestamibi SPET abnormalities after dipyridamole are almost always associated with electrical changes on body surface maps, suggesting myocardial ischaemia as their cause. The much less common 12-lead ECG changes are slower to appear and reflect a more severe hypoperfusion. (orig./MG). With 5 figs., 4 tabs

Thallium in the solar atmosphere.

Science.gov (United States)

Lambert, D. L.; Mallia, E. A.; Smith, G.

1972-01-01

Evidence for the presence of thallium in the sun is presented. Umbral spectra were found to contain an absorption feature at or near the predicted position for the Tl I 5350 A line. Analysis of the 5350 A line indicated that the solar thallium abundance is given by log N(Tl) values ranging from 0.72 to 1.07 on the standard scale log N(H) = 12.00. Unidentified blends, however, limit the accuracy of the abundance determination.

Comparison of urinary thallium levels in non-occupationally exposed people and workers.

Science.gov (United States)

Staff, James F; Cotton, Richard J; Warren, Nicholas D; Morton, Jackie

2014-04-01

To determine a reference background urinary thallium level; to compare urinary thallium data from workers to this background level; to investigate factors affecting these levels and whether creatinine correction is appropriate. Urine samples from non-occupationally exposed people (n = 273, from 113 individuals) and workers (n = 896, from 447 individuals) were analysed for thallium by ICP-MS. A reference background level was calculated, defined as the 95th percentile value of a non-occupationally exposed population. Worker data were divided into two subsets: thallium workers (those who work directly with thallium or its compounds) and general workers; and compared to the background level. Bayesian linear mixed effects modelling was used to investigate factors affecting urinary thallium concentration and the efficacy of creatinine correction for the determination of urinary thallium. The reference background urinary thallium level is 0.27 μmol/mol creatinine (creatinine-corrected) or 0.40 μg/l (uncorrected). Median values were 0.11 μmol/mol creatinine or 0.17 μg/l for non-occupationally exposed people, 0.12 μmol/mol creatinine or 0.20 μg/l for general workers and 0.19 μmol/mol creatinine or 0.41 μg/l for thallium workers. Variation was lower in creatinine-corrected models. Nine per cent of samples from general workers and 39 % of samples from thallium workers exceeded the creatinine-corrected background level. By 2010, 90 % of all workers had urinary thallium levels below the 95th percentile reference background level. Urinary thallium concentrations were higher in thallium workers than non-occupationally exposed people and general workers. Creatinine correction is appropriate.

Removal of thallium by deferasirox in rats as biological model.

Science.gov (United States)

Saljooghi, Amir Sh; Fatemi, S Jamiladin

2011-03-01

The present research aimed to characterize the potential efficiency of deferasirox in removing thallium after its administration for 30 days following two dose levels of 20 and 160 μm of thallium (III) chloride to male Wistar rats every day. After thallium administration some abnormal clinical signs such as red staining around the eyes, greenish mottling on the liver, weakness, loss of hair and weight, were observed in animals. Deferasirox was given orally to different groups of rats for a period of one week immediately after thallium administration. After chelation therapy, animals were killed by exsanguination from the abdominal aorta, and then thallium and iron concentrations in various tissues were determined by standard addition method. The chelation therapy results showed that deferasirox was able to remove thallium ions from the body and clinical symptoms were also reduced. Copyright © 2010 John Wiley & Sons, Ltd.

Thallium-201 scintigraphy in unstable angina pectoris

International Nuclear Information System (INIS)

Wackers, F.J.T.; Lie, K.I.; Liem, K.L.; Sokole, E.B.; Samson, G.; Van Der Schoot, J.B.; Durrer, D.

1978-01-01

Thallium-201 scintigraphy was performed during the pain free period in 98 patients with unstable angina. Scintiscans were positive in 39 patients, questionable in 27 patients and normal in 32 patients. Eighty-one patients responded favorably to treatment (group I). Seventeen patients had complicated courses (group II) and despite maximal treatment with propranolol either developed infarction (six patients) or continued to have angina necessitating coronary surgery (11 patients). In group I during the pain free period 26 of 81 patients had positive thallium-201 scans, whereas 20 patients had an abnormal ECG at that time; during angina 18 patients had transient ECG changes. In group II during the pain free period 13 of 17 patients had positive scans, whereas two patients had abnormal ECG at that time; during angina 12 patients showed transient ECG changes. The sensitivity to recognize group II was 76% for thallium-201 scintigraphy, 11% for ECG during the pain free period; 70% for ECG during angina; 94% for the combination of either positive scans or abnormal ECG. Thus, positive thallium-201 scans occur in patients with unstable angina, positive scans can be obtained during the pain free period, thallium-201 scans are more frequently positive in patients with complicated course

Volume and planar gated cardiac magnetic resonance imaging: a correlative study of normal anatomy with Thallium-201 SPECT and cadaver sections

International Nuclear Information System (INIS)

Go, R.T.; MacIntyre, W.J.; Yeung, H.N.

1984-01-01

Magnetic resonance (MR) gated cardiac imaging was performed in ten subjects using a prototype 0.15-T resistive magnet imaging system. Volume and planar imaging techniques utilizing saturation recovery, proton TI-weighted relaxation time pulse sequences produced images of the heart and great vessels with exquisite anatomic detail that showed excellent correlation with cadaver sections of the heart. The left ventricular myocardial segments also showed excellent correlation with cadaver sections of the heart. The left ventricular myocardial segments also showed excellent correlation with the thallium-201 cardiac single photon emission computed tomography images. Volume acquisition allowed postprocessing selection of tomographic sections in various orientations to optimize visualization of a particular structure of interest. The excellent spatial and contrast resolution afforded by MR volume imaging, which does not involve the use of ionizing radiation and iodinated contrast material, should assure it a significant role in the diagnostic assessment of the cardiovascular system

In Vitro Dissolution of Fluconazole and Dipyridamole in Gastrointestinal Simulator (GIS), Predicting in Vivo Dissolution and Drug-Drug Interaction Caused by Acid-Reducing Agents.

Science.gov (United States)

Matsui, Kazuki; Tsume, Yasuhiro; Amidon, Gregory E; Amidon, Gordon L

2015-07-06

Weakly basic drugs typically exhibit pH-dependent solubility in the physiological pH range, displaying supersaturation or precipitation along the gastrointestinal tract. Additionally, their oral bioavailabilities may be affected by coadministration of acid-reducing agents that elevate gastric pH. The purpose of this study was to assess the feasibility of a multicompartmental in vitro dissolution apparatus, Gastrointestinal Simulator (GIS), in predicting in vivo dissolution of certain oral medications. In vitro dissolution studies of fluconazole, a BCS class I, and dipyridamole, a BCS class II weak bases (class IIb), were performed in the GIS as well as United States Pharmacopeia (USP) apparatus II and compared with the results of clinical drug-drug interaction (DDI) studies. In both USP apparatus II and GIS, fluconazole completely dissolved within 60 min regardless of pH, reflecting no DDI between fluconazole and acid-reducing agents in a clinical study. On the other hand, seven-fold and 15-fold higher concentrations of dipyridamole than saturation solubility were observed in the intestinal compartments in GIS with gastric pH 2.0. Precipitation of dipyridamole was also observed in the GIS, and the percentage of dipyridamole in solution was 45.2 ± 7.0%. In GIS with gastric pH 6.0, mimicking the coadministration of acid-reducing agents, the concentration of dipyridamole was equal to its saturation solubility, and the percentage of drug in solution was 9.3 ± 2.7%. These results are consistent with the clinical DDI study of dipyridamole with famotidine, which significantly reduced the Cmax and area under the curve. An In situ mouse infusion study combined with GIS revealed that high concentration of dipyridamole in the GIS enhanced oral drug absorption, which confirmed the supersaturation of dipyridamole. In conclusion, GIS was shown to be a useful apparatus to predict in vivo dissolution for BCS class IIb drugs.

[Detoxification effects of two drugs in thallium -poisoned mice].

Science.gov (United States)

Wang, Ying; He, Yue-zhong; Zhang, Xi-gang

2012-06-01

To observe the thallium eliminating effect of prussian blue, pentetate zinc trisodium (Zn-DTPA), and their combined use in the treatment of acute thallium poisoning in mice. Thallium poisoned mice were reproduced by oral administration of 0.2 ml thallous nitrate (3 mg/ml). They were assigned randomly to four groups according to the random number table method, namely, model group, prussian blue group, Zn-DTPA group and the combination therapy group, with 10 mice in each group. Prussian blue was administered orally [4.52 g×kg(-1)×d(-1), total four times], and Zn-DTPA was injected intraperitoneally [500 mg×kg(-1)×d(-1), one time]4 hours after giving thallium. The dosage of both drugs in combination treatment was as the same as described above. After treatment for 5 days, all the animals were sacrificed. Brain, intestine, kidney and liver of 1 mouse from each group were collected for pathological examination to observe the necrosis. Thallium contents of blood, brain, urine and feces from the other mice were determined. Pathological examination showed that the damage to intestine, kidney and liver was less obvious in treatment group compared with those of the model group. The effect was most obvious in the combination treatment group. However, brain damage was slightly improved. Thallium content in blood (mg/ml) of prussian blue group and the combination treatment group decreased obviously compared with the model group, and the decrease was more obvious in the combination treatment group (0.05 ± 0.01 vs. 0.18 ± 0.02). Thallium content in urine (mg/ml) and feces (mg/kg) was significantly increased after treatment, and the thallium elimination was most significant in the combined treatment group (urine: 11.34 ± 0.81 vs. 0.02 ± 0.01, feces: 13.11 ± 1.84 vs. 0.21 ± 0.07, both P Thallium content in brain was similar among all the groups. The single and combined use of prussian blue and Zn-DTPA could reduce the damage in intestine, kidney and liver. Combined use of

Human fatality due to thallium poisoning: autopsy, microscopy, and mass spectrometry assays.

Science.gov (United States)

Li, Shangxun; Huang, Wen; Duan, Yijie; Xing, Jingjun; Zhou, Yiwu

2015-01-01

Thallium has been responsible for many intoxications since its discovery; however, toxicological profiles for thallium in human fatalities have not been updated recently. Autopsy, microscopic investigations, and toxicological analyses were performed on a married couple who died from thallium sulfate intended homicidal poisoning. The distribution of thallium was established by inductively coupled plasma mass spectrometry with hair samples showing the highest thallium concentration. Electron microscopy revealed a dystrophic condition of hair with disorganized cuticle and atrophy of the hair bulb. Thallium interacts with cells at different levels, with prominent ultrastructural injuries in the mitochondria and endoplasmic reticulum, and high concentration of electron dense granules observed in the cytoplasm and mitochondria of several organs. Alopecia, toxic encephalopathy, and peripheral neuropathy were diagnosed in the victims and suggested to be crucial implications for thallium poisoning. The analytical procedures used in this case are of considerable forensic importance in the diagnosis of thallium poisoning. © 2014 American Academy of Forensic Sciences.

Preoperative physical examination and imaging of femoroacetabular impingement prior to hip arthroscopy-a systematic review.

Science.gov (United States)

Haldane, Chloe E; Ekhtiari, Seper; de Sa, Darren; Simunovic, Nicole; Ayeni, Olufemi R

2017-08-01

The purpose of this systematic review is to report current preoperative assessment for femoroacetabular impingement (FAI) including physical examination and imaging modalities prior to hip arthroscopy, and report current imaging measures used in the diagnosis of FAI. The electronic databases MEDLINE, EMBASE and PubMed were searched and screened in duplicate for relevant studies. Data regarding patient demographics, non-operative treatment, preoperative assessment including physical examination and imaging prior to hip arthroscopy were abstracted. Study quality was assessed in duplicate using the Methodological Index for Non-Randomized Studies criteria. Sixty-eight studies of fair quality evidence that involved a total of 5125 patients (5400 hips) were included. In total, 56% of all patients were male and mean age was 36 years (SD ± 10.0). Within physical examination, FADIR impingement testing was reported in 57% of patients. All included studies reported plain radiographic imaging as a component of preoperative assessment with anterior-posterior pelvis view being the most commonly reported view, followed by the cross-table lateral and Dunn views. Magnetic resonance imaging was obtained for 52% of included patients and computed tomography for 26% of patients. The most commonly reported measure within imaging for the diagnosis of cam type impingement was alpha angle (66%), whereas for pincer type impingement, the cross-over sign (48%) was most reported. Preoperative assessment is underreported in the FAI literature. Improved reporting is warranted to develop a more consistent and validated diagnostic algorithm for FAI to enhance patient selection. Level of evidence : Level IV, Systematic Review of Level I-IV Studies.

Preoperative physical examination and imaging of femoroacetabular impingement prior to hip arthroscopy—a systematic review

Science.gov (United States)

Haldane, Chloe E.; Ekhtiari, Seper; de SA, Darren; Simunovic, Nicole

2017-01-01

Abstract The purpose of this systematic review is to report current preoperative assessment for femoroacetabular impingement (FAI) including physical examination and imaging modalities prior to hip arthroscopy, and report current imaging measures used in the diagnosis of FAI. The electronic databases MEDLINE, EMBASE and PubMed were searched and screened in duplicate for relevant studies. Data regarding patient demographics, non-operative treatment, preoperative assessment including physical examination and imaging prior to hip arthroscopy were abstracted. Study quality was assessed in duplicate using the Methodological Index for Non-Randomized Studies criteria. Sixty-eight studies of fair quality evidence that involved a total of 5125 patients (5400 hips) were included. In total, 56% of all patients were male and mean age was 36 years (SD ± 10.0). Within physical examination, FADIR impingement testing was reported in 57% of patients. All included studies reported plain radiographic imaging as a component of preoperative assessment with anterior–posterior pelvis view being the most commonly reported view, followed by the cross-table lateral and Dunn views. Magnetic resonance imaging was obtained for 52% of included patients and computed tomography for 26% of patients. The most commonly reported measure within imaging for the diagnosis of cam type impingement was alpha angle (66%), whereas for pincer type impingement, the cross-over sign (48%) was most reported. Preoperative assessment is underreported in the FAI literature. Improved reporting is warranted to develop a more consistent and validated diagnostic algorithm for FAI to enhance patient selection. Level of evidence: Level IV, Systematic Review of Level I–IV Studies. PMID:28948032

Detecting thyroid cancer: utopia or reality; possibilities for thallium 201

International Nuclear Information System (INIS)

Hermans, J.; Beauduin, M.; Gigot, J.F.; Schmitz, A.

1986-01-01

Faced with a diagnosis of cold thyroid nodule as evidenced by routine scintigraphy, the clinician has to determine whether this nodule is malignant or not. This is a serious problem since, according to literature, 7-20 per cent of cold thyroid nodules are malignant. In 1982 some Japanese authors demonstrated the possibility of using 201 T1 in diagnosing thyroid tumors. This study refers to 120 patients who underwent an operation for thyroid disorders characterized by the presence of one or several cold nodules (as evaluated with conventional scintigraphy) and enables a comparison between a thorough evaluation of the thyroidal status and the 201 T1 scintigrams. These were obtained with a gamma-camera using a pinhole collimator. If a cold nodule is positive with 201 T1, surgery is incontestably indicated, as such a finding correlates with the existence of a thyroid tumor (benign follicular adenoma or carcinoma) in 89.5 per cent of the observed cases. In the cancer group the sensibility of the Thallium test is of 85 per cent and its specificity 80 per cent. We may assert that there is a very low risk of Thallium negative (old) nodules being malignant. The pre-operative 201 T1 scintigraphy is easy to perform in any Nuclear Medicine department. Nowadays, the combination of aspiration cytology and 201 T1 scintigraphy should make it possible to make an accurate diagnosis in the vast majority of differentiated and undifferentiated thyroid cancers [fr

Prediction of single versus multivessel disease following myocardial infarction using 201-thallium scintigraphy and electrocardiographic stress testing

International Nuclear Information System (INIS)

Weiss, R.J.; Morise, A.P.; Raabe, D.S. Jr.; Sbarbaro, J.A.

1983-01-01

Fifty patients were evaluated who suffered a single myocardial infarction with graded electrocardiographic stress testing, 201-thallium myocardial perfusion imaging and coronary angiography to assess the role of noninvasive indices as predictors of single versus multivessel coronary artery disease. Multivessel involvement was defined angiographically as the presence of two or more major coronary arteries with at least a 70% intraluminal diameter narrowing. Multivessel disease was defined scintigraphically as the presence of stress and/or redistribution perfusion defects in the distribution of more than one coronary artery. The results of stress electrocardiography were not useful in differentiating patients with single (9/16 positive) versus multivessel (22/34 positive) disease. The degree of exercise-induced ST-segment depression was also not helpful. Stress 201-thallium imaging did offer limited additional information with correct predictions of multivessel disease in 21 of 26 patients. Predictions of single-vessel disease were accurate in 11 of 24 patients. Eleven of these 13 incorrect predictions of single-vessel disease were due to the relative insensitivity of the thallium stress image to perceive defect in the anterior wall when the left anterior descending artery had significant obstruction at catheterization. Further refinements of stress perfusion imaging are needed before this method can be used to reliably separate patients with single and multivessel disease after myocardial infarction

Carcinoma of the Thyroid. Preoperative diagnostic and prognostic factors

International Nuclear Information System (INIS)

Tennvall, J.

1984-01-01

By improving preoperative diagnosis and identification of important prognostic factors of thyroid carcinoma (TC) it might be possible to decrease the number of diagnostic surgical intervantions and to give patients with a confirmed TC a more adequate treatment. Preoperative diagnosis: consecutive series of 83 patients with scintigrams and of 203 patients with fine-needle aspiration (AC) with subsequently histologically confirmed TC were evaluated as well as 217 patients with confirmed benign thyroid disorders. The most common scintigraphic appearance was a solitary reduced uptake (70%). The sensitivity of AC for medullary and undifferentiated TC was 0.82-0.84, but it was for papillary (occult TC excluded) 0.58 and for follicular TC 0.42. A 'cold' nodule with also a decreased thallium-uptake is mostly a benign disorder, but with an increased uptake it might be a well-differentiated TC or a follicular adenoma. These could, however, be significantly separated by the thallium-elimination rate (p=0.0001). Prognostic factors: During 1955-1972, 262 patients with histologically verified TC were referred to the Department and 226 of these (86%) with a median follow-up of 11 years form the basis for prognostic multivariate analyses. According to these analyses, and when deaths in intercurrent disease were estimated, neither age at diagnosis nor sex were found to be important predictors of survival of TC. The following predictors were identified: for papillary TC: tumour extension beyond the thyroid capsule and marked cellular atypia; for follicular TC: tumour extension beyond the thyroid capsule, marked cellular atypia and distant metastases; for medullary TC: tumour extension beyond the thyroid capsule. (Author)

[Efficiency of hemoperfusion on clearing thallium based on atomic absorption spectrometry].

Science.gov (United States)

Tian, Tian; Wang, Yongan; Nie, Zhiyong; Wang, Jiao; Peng, Xiaobo; Yuan, Ye; Li, Wanhua; Qiu, Zewu; Xue, Yanping; Xiong, Yiru

2015-04-01

To determine thallium in whole blood by atomic absorption detection method, and to investigate the eliminating effect of hemoperfusion (HP) for thallium in blood. The blood of Beagle dogs which had not exposed to thallium before were obtained for preparation of thallium nitrate ( TlNO3 )-containing solution in three concentrations according to the conversion formula based on animal weight and volume of blood. HP was performed in the simulated in vivo environment. The content of TlNO3 in blood of the next group was determined on the amount of TlNO3 for the last HP of the former dose group. Thallium quantity in different samples was measured with atomic absorption spectrometer blood samples before and after HP. Finally, the thallium concentration in blood was analyzed statistically. Thallium concentrations showed a good linear relationship in the range of 0-200 μg/L (r = 0.998 4). The intra-day precision (RSD) was lower than 4.913%, the intra-day recovery rate was 96.2%-111.9%; the inter-day precision (RSD) was lower than 7.502%, the inter-day recovery rate was 89.6%-105.2%. The concentration of thallium in blood was significantly reduced after HP per time in high, middle, and low dose groups [(453.43 ± 27.80) mg/L to (56.09 ± 14.44) mg/L in high dose group, F = 8.820, P = 0.003; (64.51 ± 13.60) mg/L to (3.19 ± 0.23) mg/L in middle dose group, F = 36.312, P = 0.000; (5.40 ± 0.98) mg/L to (0.38 ± 0.25) mg/L in low dose group, F = 46.240, P = 0.000 ]. The adsorption rate of four times of HP in high, middle and low dose group were (87.63 ± 2.48 )%, (95.06 ± 1.54 )% and (92.76 ± 4.87)%, respectively, without significant difference (F = 4.231, P = 0.070). The method for measuring thallium was established, and it shows a very stable, simple, sensitive for determination of thallium. HP can effectively remove thallium from blood. Thallium concentration can be reduced by 90% after four times of HP. HP is also effective even when thallium concentration is not high.

Preoperative functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS)

DEFF Research Database (Denmark)

Hartwigsen, G.; Siebner, Hartwig R.; Stippich, C.

2010-01-01

Neurosurgical resection of brain lesions aims to maximize excision while minimizing the risk of permanent injury to the surrounding intact brain tissue and resulting neurological deficits. While direct electrical cortical stimulation at the time of surgery allows the precise identification...... of essential cortex, it cannot provide information preoperatively for surgical planning.Brain imaging techniques such as functional magnetic resonance imaging (fMRI), magnetoencephalography (MEG) and transcranial magnetic stimulation (TMS) are increasingly being used to localize functionally critical cortical......, if the stimulated cortex makes a critical contribution to the brain functions subserving the task. While the relationship between task and functional activation as revealed by fMRI is correlative in nature, the neurodisruptive effect of TMS reflects a causal effect on brain activity.The use of preoperative f...

Selective Thallium (I Ion Sensor Based on Functionalised ZnO Nanorods

Directory of Open Access Journals (Sweden)

Z. H. Ibupoto

2012-01-01

Full Text Available Well controlled in length and highly aligned ZnO nanorods were grown on the gold-coated glass substrate by hydrothermal growth method. ZnO nanorods were functionalised with selective thallium (I ion ionophore dibenzyldiaza-18-crown-6 (DBzDA18C6. The thallium ion sensor showed wide linear potentiometric response to thallium (I ion concentrations ( M to  M with high sensitivity of 36.87 ± 1.49 mV/decade. Moreover, thallium (I ion demonstrated fast response time of less than 5 s, high selectivity, reproducibility, storage stability, and negligible response to common interferents. The proposed thallium (I ion-sensor electrode was also used as an indicator electrode in the potentiometric titration, and it has shown good stoichiometric response for the determination of thallium (I ion.

Preoperative magnetic resonance and intraoperative ultrasound fusion imaging for real-time neuronavigation in brain tumor surgery.

Science.gov (United States)

Prada, F; Del Bene, M; Mattei, L; Lodigiani, L; DeBeni, S; Kolev, V; Vetrano, I; Solbiati, L; Sakas, G; DiMeco, F

2015-04-01

Brain shift and tissue deformation during surgery for intracranial lesions are the main actual limitations of neuro-navigation (NN), which currently relies mainly on preoperative imaging. Ultrasound (US), being a real-time imaging modality, is becoming progressively more widespread during neurosurgical procedures, but most neurosurgeons, trained on axial computed tomography (CT) and magnetic resonance imaging (MRI) slices, lack specific US training and have difficulties recognizing anatomic structures with the same confidence as in preoperative imaging. Therefore real-time intraoperative fusion imaging (FI) between preoperative imaging and intraoperative ultrasound (ioUS) for virtual navigation (VN) is highly desirable. We describe our procedure for real-time navigation during surgery for different cerebral lesions. We performed fusion imaging with virtual navigation for patients undergoing surgery for brain lesion removal using an ultrasound-based real-time neuro-navigation system that fuses intraoperative cerebral ultrasound with preoperative MRI and simultaneously displays an MRI slice coplanar to an ioUS image. 58 patients underwent surgery at our institution for intracranial lesion removal with image guidance using a US system equipped with fusion imaging for neuro-navigation. In all cases the initial (external) registration error obtained by the corresponding anatomical landmark procedure was below 2 mm and the craniotomy was correctly placed. The transdural window gave satisfactory US image quality and the lesion was always detectable and measurable on both axes. Brain shift/deformation correction has been successfully employed in 42 cases to restore the co-registration during surgery. The accuracy of ioUS/MRI fusion/overlapping was confirmed intraoperatively under direct visualization of anatomic landmarks and the error was surgery and is less expensive and time-consuming than other intraoperative imaging techniques, offering high precision and

Submaximal exercise thallium-201 SPECT for assessment of interventional therapy in patients with acute myocardial infarction

International Nuclear Information System (INIS)

Stewart, R.E.; Kander, N.; Juni, J.E.; Ellis, S.G.; O'Neill, W.W.; Schork, M.A.; Topol, E.J.; Schwaiger, M.

1991-01-01

Submaximal thallium-201 stress testing has been shown to provide important diagnostic and prognostic information in patients with acute myocardial infarction. The purpose of this investigation was to evaluate the diagnostic value of early submaximal stress testing and thallium-201 single photon emission computed tomography (SPECT) after interventional therapy. Scintigraphic results from 56 patients with infarctions, who underwent acute thrombolytic therapy, angioplasty, or both, were compared with late (6 weeks) functional outcome as assessed by radionuclide ventriculography and with results of discharge coronary angiography. A linear correlation was found between the extent of thallium-201 SPECT perfusion defect and late ventricular function (r = 0.74, p less than 0.01). Forty-two percent of patients with large SPECT perfusion defects had normal left ventricular ejection fractions, suggesting an overestimation of infarct size by early imaging. Sensitivity and specificity of thallium-201 SPECT for detection of coronary artery stenosis in noninfarct territories was 57% and 46%, respectively, indicating limited diagnostic definition of extent of underlying coronary artery disease. Results of follow-up coronary angiography showed a significant relationship between the size of the initial perfusion defect and early restenosis or reocclusion of the infarct artery. Thus the extent of early thallium-201 perfusion defects correlates with late functional outcome but appears to overestimate the degree of injury. Submaximal thallium-201 stress testing allows only limited characterization of underlying coronary artery disease. Early assessment of infarct size may identify a patient population at high risk for reocclusion of the infarct artery

Nuclear cardiology: Myocardial perfusion and function

International Nuclear Information System (INIS)

Seldin, D.W.

1991-01-01

Myocardial perfusion studies continue to be a major focus of research, with new investigations of the relationship of exercise-redistribution thallium imaging to diagnosis, prognosis, and case management. The redistribution phenomenon, which seemed to be fairly well understood a few years ago, is now recognized to be much more complex than originally thought, and various strategies have been proposed to clarify the meaning of persistent defects. Pharmacologic intervention with dipyridamole and adenosine has become available as an alternative to exercise, and comparisons with exercise imaging and catheterization results have been described. Thallium itself is no longer the sole single-photon perfusion radiopharmaceutical; two new technetium agents are now widely available. In addition to perfusion studies, advances in the study of ventricular function have been made, including reports of studies performed in conjunction with technetium perfusion studies, new insights into cardiac physiology, and the prognostic and case-management information that function studies provide. Finally, work has continued with monoclonal antibodies for the identification of areas of myocyte necrosis. 41 references

Chelation of thallium by combining deferasirox and desferrioxamine in rats.

Science.gov (United States)

Saljooghi, Amir Shokooh; Babaie, Maryam; Mendi, Fatemeh Delavar; Zahmati, Maliheh; Saljooghi, Zoheir Shokouh

2016-01-01

The hypothesis that two known chelators deferasirox (4-[3,5-bis(2-hydroxyphenyl)-1,2,4-triazol-1-yl]-benzoic acid) and desferrioxamine (DFO) might be more efficient as combined treatment than as monotherapies in removing thallium from the body was tested in a new acute rat model. 7-week-old male Wistar rats received chelators: deferasirox (orally), DFO (intraperitoneal; i.p.), or deferasirox + DFO as 75 or 150 mg/kg dose half an hour after a single i.p. administration of 8 mg thallium/kg body weight in the form of chloride. Serum thallium concentration, urinary thallium, and iron excretions were determined by graphite furnace atomic absorption spectrometry. Both chelators were effective only at the higher dose level, while DFO was more effective than deferasirox in enhancing urinary thallium excretion, deferasirox was more effective than DFO in enhancing urinary iron excretion. In the combined treatment group, deferasirox did not increase the DFO effect on thallium and DFO did not increase the effect of deferasirox on iron elimination. Our results support the usefulness of this animal model for preliminary in vivo testing of thallium chelators. Urinary values were more useful because of the high variability of serum results. © The Author(s) 2013.

New Exercise-Dipyridamole Combined Test for Nuclear Cardiology in Insufficient Effort: Appropriate Diagnostic Sensitivity Keeping Exercise Prognosis

Energy Technology Data Exchange (ETDEWEB)

Cortinas, Inés Vidal, E-mail: invi@montevideo.com.uy; Beretta, Mario; Alonso, Omar; Mut, Fernando [Departamento de Medicina Nuclear do Hospital ‘Asociación Española’, Br. Artigas 1515, Montevideo (Uruguay)

2015-08-15

Myocardial perfusion scintigraphy (MPS) in patients not reaching 85% of the maximum predicted heart rate (MPHR) has reduced sensitivity. In an attempt to maintain diagnostic sensitivity without losing functional exercise data, a new exercise and dipyridamole combined protocol (EDCP) was developed. Our aim was to evaluate the feasibility and safety of this protocol and to compare its diagnostic sensitivity against standard exercise and dipyridamole protocols. In patients not reaching a sufficient exercise (SE) test and with no contraindications, 0.56 mg/kg of dipyridamole were IV administered over 1 minute simultaneously with exercise, followed by 99mTc-MIBI injection. Of 155 patients, 41 had MPS with EDCP, 47 had a SE test (≥ 85% MPHR) and 67 underwent the dipyridamole alone test (DIP). They all underwent coronary angiography within 3 months. The three stress methods for diagnosis of coronary lesions had their sensitivity compared. For stenosis ≥ 70%, EDCP yielded 97% sensitivity, SE 90% and DIP 95% (p = 0.43). For lesions ≥ 50%, the sensitivities were 94%, 88% and 95%, respectively (p = 0.35). Side effects of EDCP were present in only 12% of the patients, significantly less than with DIP (p < 0.001). The proposed combined protocol is a valid and safe method that yields adequate diagnostic sensitivity, keeping exercise prognostic information in patients unable to reach target heart rate, with fewer side effects than the DIP.

The value and limitation thallium scintigraphy in the detection of coronary artery disease

International Nuclear Information System (INIS)

Khan, A.; Rehman, A.; Amin, W.; Khan, Z.A.; Ahmed, S.A.

1986-01-01

In this study we randomly selected 45 patients whose coronary angiograms were abnormal i.e. showing triple, double and single vessel disease out of a pool of 80 patients who had undergone stress thallium imaging and coronary angiography during the one year. Majority of these patients were males, their ages ranged between 34-54 years. Resting ECG's were normal in 25 patients, 15 patients had suffered inferior myocardial infraction and 5 had sustained anterior myocardial infraction in the past. Coronary angiography revealed triple vessel disease in 20 patients, double vessel disease in 15, and single vessel coronary artery disease in 10. We analysed their coronary angiograms and compared them with the scintigraphic finding. It is concluded that although thallium scanning has high sensitivity for detection of coronary artery disease in general, it has only moderate sensitivity for detection of stenosis in individual coronary arteries. In this study thallium scan identified 75% of RCA lesions, 66% of LAD lesions and 38% of circumflex lesions. The sensitivity is much higher in single vessel coronary artery disease. (author)

Exercise-induced thallium-201 myocardial perfusion defects in angina pectoris without significant coronary artery stenosis

International Nuclear Information System (INIS)

Nakazato, Masayasu; Maruoka, Yuji; Sunagawa, Osahiko; Kinjo, Kunihiko; Tomori, Masayuki; Fukiyama, Koshiro

1990-01-01

We performed exercise thallium-201 myocardial scintigraphy in 32 patients with angina pectoris to study the incidence of perfusion defects, who had no significant organic stenosis on coronary angiography. None of them had myocardial infarction or cardiomyopathy. Thallium-201 myocardial scintigraphy and 12-lead ECG recording were performed during supine bicycle ergometer exercise. Perfusion defects in thallium-201 scintigrams in SPECT images were assessed during visual analysis by two observers. In the coronary angiograms obtained during intravenous infusion of nitroglycerin, the luminal diameter of 75% stenosis or less in the AHA classification was regarded as an insignificant organic stenosis. Myocardial perfusion defects in the thallium-201 scintigrams were detected in eight (25%) of the 32 patients. Six of these eight patients had variant angina documented during spontaneous attacks with ST elevations in standard 12-lead ECGs. Perfusion defects were demonstrated at the inferior or infero-posterior regions in six patients, one of whom had concomitant anteroseptal defect. The defects were not always accompanied by chest pain. All but one patient demonstrating inferior or inferoposterior defects showed ST depression in leads II, III and aV F on their ECGs, corresponding to inferior wall ischemia. The exception was a case with right bundle branch block. Thus, 25% of the patients with angina pectoris, who had no evidence of significant organic stenosis on their coronary angiograms, exhibited exercise-induced perfusion defects in their thallium-201 scintigrams. Coronary spasms might have caused myocardial ischemia in these patients. (author)

ST segment/heart rate slope as a predictor of coronary artery disease: comparison with quantitative thallium imaging and conventional ST segment criteria

International Nuclear Information System (INIS)

Finkelhor, R.S.; Newhouse, K.E.; Vrobel, T.R.; Miron, S.D.; Bahler, R.C.

1986-01-01

The ST segment shift relative to exercise-induced increments in heart rate, the ST/heart rate slope (ST/HR slope), has been proposed as a more accurate ECG criterion for diagnosing significant coronary artery disease (CAD). Its clinical utility, with the use of a standard treadmill protocol, was compared with quantitative stress thallium (TI) and standard treadmill criteria in 64 unselected patients who underwent coronary angiography. The overall diagnostic accuracy of the ST/HR slope was an improvement over TI and conventional ST criteria (81%, 67%, and 69%). For patients failing to reach 85% of their age-predicted maximal heart rate, its diagnostic accuracy was comparable with TI (77% and 74%). Its sensitivity in patients without prior myocardial infarctions was equivalent to that of thallium (91% and 95%). The ST/HR slope was directly related to the angiographic severity (Gensini score) of CAD in patients without a prior infarction (r = 0.61, p less than 0.001). The ST/HR slope was an improved ECG criterion for diagnosing CAD and compared favorably with TI imaging

[Nervous system involvement in three children poisoned with thallium].

Science.gov (United States)

Gergont, Aleksandra; Lankosz-Lauterbach, Janina; Pietrzyk, Jacek J; Kaciński, Marek

2004-01-01

Three children, aged 5, 10 and 16 years, poisoned with thallium were hospitalized. Two of them suffered from sensory-motor and third from sensory polyneuropathy and additionally in the youngest child severe encephalopathy was observed. The correlations between serum and urine thallium levels and the severity of the symptoms in the course of the disease were positive. The most severe symptoms and the highest thallium level were observed in the youngest child.

Magnetic resonance imaging in familial hypertrophic cardiomyopathy associated with abnormal thallium perfusion and cardiac enzymes

Energy Technology Data Exchange (ETDEWEB)

Nishimura, Tsunehiko; Nagata, Seiki; Sakakibara, Hiroshi

1988-05-01

Gated magnetic resonance imaging (MRI) was performed in 6 patients with familial hypertrophic cardiomyopathy associated with abnormal thallium perfusion, and 12 patients with ordinary hypertrophic cardiomyopathy. The patients with ordinary hypertrophic cardiomyopathy and abnormal thickening of the septal wall and normal left ventricular dimensions, while the patients with familial hypertrophic cardiomyopathy had focal wall thinning (usually involving the apical-septal wall) and dilated left ventricle in addition to hypertrophied heart. The quantitative measurement for cardiac dimensions using MRI was similar to that found on echocardiography in all cases. In addition, inhomogeneous signal intensities at left ventricular wall were observed in 3 cases of familial hypertrophic cardiomyopathy, which may suggest the existence of myocardial fibrosis. Gated MRI should be performed for early detection and follow-up of hypertrophic cardiomyopathy, since some patients will progress from hypertrophic cardiomyopathy to dilated cardiomyopathy.

Clinical evaluation of stress thallium spect in ischemic heart disease

International Nuclear Information System (INIS)

Sui, Osamu; Kimura, Nazuna; Soeki; Takeshi; Takeichi, Naoki; Shinohara, Hisanori; Tamura, Yoshiyuki; Fukuda, Nobuo

1997-01-01

Thallium SPECT was performed in patients with significant coronary artery stenosis, 67 cases were after maximal exercise and 74 cases were during coronary vasodilation induced by ATP (adenosine triphosphate) infusion. In patients suspected of angina pectoris, the sensitivity, specificity and predictive accuracy for detection of coronary artery disease (CAD) were 88%, 78% and 82% for exercise SPECT, and 100%, 72% and 84% for ATP SPECT studies, respectively. In patients with old myocardial infarction, these were 73%, 100% and 88% for exercise SPECT and 71%, 100% and 81% for ATP SPECT. These were 75%, 49% and 60% for treadmill exercise test in the patient group including both angina and myocardial infarction. For detection of diseased vessels, the diagnostic accuracy for left anterior descending artery and right coronary artery lesions was almost equal for ATP and exercise SPECT study, but ATP SPECT study was more sensitive than exercise SPECT study in detection of left circumflex artery lesions. ATP as well as exercise SPECT studies occasionally gave false positive results in patients with single-vessel disease. ATP as well as exercise SPECT studies underestimated the severity of multi-vessel disease. In general, the results of ATP SPECT imaging were highly concordant with the results of exercise SPECT imaging. ATP stress thallium SPECT imaging provided a safe and highly accurate diagnostic tool for detection of CAD. (author)

Electron spin resonance of vanadium(4)-thallium(1) dithiocarbamate complexes

International Nuclear Information System (INIS)

Ivanov, A.V.; Solozhenkin, P.M.; Baratova, Z.R.; Klyashtornyj, V.B.; Uskov, V.Yu.

1990-01-01

Heteronuclear vanadium(4), thallium(1) dithiocarbanate complexes of the composition TlVO(Dtc) 3 and Tl 2 VO(Dtc) 4 under conditions of magnetic dilution were studied by ESR spectroscopy. Magnetically diluted complexes were prepared by coprecipitation from aqueous solutions of thallium(1) and oxovanadium(2) by solutions of sodium diethyldithiocarbamate, dibutyldithiocarbamate, hexamethylenedithiocarbamate, taken in superstoichiometric excess. Analysis of parameters of ESR spectra of the complexes synthesized shows that thallium atoms are not included in the first coordination sphere of oxovanadium(2), and chelate node VS 4 in thallium(1) complex lattice practically preserves its plane quadratic structure

National variation in preoperative imaging, carotid duplex ultrasound criteria, and threshold for surgery for asymptomatic carotid artery stenosis.

Science.gov (United States)

Arous, Edward J; Simons, Jessica P; Flahive, Julie M; Beck, Adam W; Stone, David H; Hoel, Andrew W; Messina, Louis M; Schanzer, Andres

2015-10-01

Carotid endarterectomy (CEA) for asymptomatic carotid artery stenosis is among the most common procedures performed in the United States. However, consensus is lacking regarding optimal preoperative imaging, carotid duplex ultrasound criteria, and ultimately, the threshold for surgery. We sought to characterize national variation in preoperative imaging, carotid duplex ultrasound criteria, and threshold for surgery for asymptomatic CEA. The Society for Vascular Surgery Vascular Quality Initiative (VQI) database was used to identify all CEA procedures performed for asymptomatic carotid artery stenosis between 2003 and 2014. VQI currently captures 100% of CEA procedures performed at >300 centers by >2000 physicians nationwide. Three analyses were performed to quantify the variation in (1) preoperative imaging, (2) carotid duplex ultrasound criteria, and (3) threshold for surgery. Of 35,695 CEA procedures in 33,488 patients, the study cohort was limited to 19,610 CEA procedures (55%) performed for asymptomatic disease. The preoperative imaging modality used before CEA varied widely, with 57% of patients receiving a single preoperative imaging study (duplex ultrasound imaging, 46%; computed tomography angiography, 7.5%; magnetic resonance angiography, 2.0%; cerebral angiography, 1.3%) and 43% of patients receiving multiple preoperative imaging studies. Of the 16,452 asymptomatic patients (89%) who underwent preoperative duplex ultrasound imaging, there was significant variability between centers in the degree of stenosis (50%-69%, 70%-79%, 80%-99%) designated for a given peak systolic velocity, end diastolic velocity, and internal carotid artery-to-common carotid artery ratio. Although 68% of CEA procedures in asymptomatic patients were performed for an 80% to 99% stenosis, 26% were performed for a 70% to 79% stenosis, and 4.1% were performed for a 50% to 69% stenosis. At the surgeon level, the range in the percentage of CEA procedures performed for a duplex ultrasound

Avoiding preoperative breast MRI when conventional imaging is sufficient to stage patients eligible for breast conserving therapy

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Pengel, Kenneth E., E-mail: k.pengel@nki.nl [Department of Radiology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam (Netherlands); Loo, Claudette E. [Department of Radiology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam (Netherlands); Wesseling, Jelle [Department of Pathology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam (Netherlands); Pijnappel, Ruud M. [Department of Radiology/Image Sciences Institute, University Medical Center Utrecht Heidelberglaan 100, 3584 CX Utrecht (Netherlands); Rutgers, Emiel J.Th. [Department of Surgical Oncology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam (Netherlands); Gilhuijs, Kenneth G.A. [Department of Radiology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam (Netherlands); Department of Radiology/Image Sciences Institute, University Medical Center Utrecht Heidelberglaan 100, 3584 CX Utrecht (Netherlands)

2014-02-15

Aim: To determine when preoperative breast MRI will not be more informative than available breast imaging and can be omitted in patients eligible for breast conserving therapy (BCT). Methods: We performed an MRI in 685 consecutive patients with 692 invasive breast tumors and eligible for BCT based on conventional imaging and clinical examination. We explored associations between patient, tumor, and conventional imaging characteristics and similarity with MRI findings. Receiver operating characteristic (ROC) analysis was employed to compute the area under the curve (AUC). Results: MRI and conventional breast imaging were similar in 585 of the 692 tumors (85%). At univariate analysis, age (p < 0.001), negative preoperative lymph node status (p = 0.011), comparable tumor diameter at mammography and at ultrasound (p = 0.001), negative HER2 status (p = 0.044), and absence of invasive lobular cancer (p = 0.005) were significantly associated with this similarity. At multivariate analysis, these factors, except HER2 status, retained significant associations. The AUC was 0.68. Conclusions: It is feasible to identify a subgroup of patients prior to preoperative breast MRI, who will most likely show similar results on conventional imaging as on MRI. These findings enable formulation of a practical consensus guideline to determine in which patients a preoperative breast MRI can be omitted.

Avoiding preoperative breast MRI when conventional imaging is sufficient to stage patients eligible for breast conserving therapy

International Nuclear Information System (INIS)

Pengel, Kenneth E.; Loo, Claudette E.; Wesseling, Jelle; Pijnappel, Ruud M.; Rutgers, Emiel J.Th.; Gilhuijs, Kenneth G.A.

2014-01-01

Aim: To determine when preoperative breast MRI will not be more informative than available breast imaging and can be omitted in patients eligible for breast conserving therapy (BCT). Methods: We performed an MRI in 685 consecutive patients with 692 invasive breast tumors and eligible for BCT based on conventional imaging and clinical examination. We explored associations between patient, tumor, and conventional imaging characteristics and similarity with MRI findings. Receiver operating characteristic (ROC) analysis was employed to compute the area under the curve (AUC). Results: MRI and conventional breast imaging were similar in 585 of the 692 tumors (85%). At univariate analysis, age (p < 0.001), negative preoperative lymph node status (p = 0.011), comparable tumor diameter at mammography and at ultrasound (p = 0.001), negative HER2 status (p = 0.044), and absence of invasive lobular cancer (p = 0.005) were significantly associated with this similarity. At multivariate analysis, these factors, except HER2 status, retained significant associations. The AUC was 0.68. Conclusions: It is feasible to identify a subgroup of patients prior to preoperative breast MRI, who will most likely show similar results on conventional imaging as on MRI. These findings enable formulation of a practical consensus guideline to determine in which patients a preoperative breast MRI can be omitted

Assessment of myocardial viability in patients with myocardial infarction using twenty-four hour thallium-201 late redistribution imaging

International Nuclear Information System (INIS)

Yang Xiangjun; He Yongming; Zhang Bin; Wu Yiwei; Hui Jie; Jiang Tingbo; Song Jianping; Liu Zhihua; Jiang Wenping

2006-01-01

Rest thallium-201 ( 201 Tl) myocardial perfusion imaging has been widely used for evaluation of myocardial ischemia/viability after myocardial infarction, but the ideal timing for imaging after injection to maximally estimate viability is not well established. Thirty-six patients with myocardial infarction underwent the initial, 3 h, and 24 h redistribution imaging after intravenous injection of 148-185 MBq 201 Tl. The initial and 3 h images, the initial and 24 h images, and the 3 and 24 h images were compared double-blinded. Out of the 184 abnormal segments based on the initial imaging, 56 (30%) segments improved by at least 1 grade on the 3 h imaging while 78 (42%) segments improved by at least 1 grade on the 24 h imaging. The 24 h late imaging detected more viable myocardium than the 3 h imaging did, with a significant difference (χ 2 =5.680, p=0.017). There were 158 abnormal segments on the 3 h imaging, with average 28% (44) segments improved by at least 1 grade on the 24 h imaging. There were 128 initial abnormal segments with no improvement on the 3 h imaging. Out of these segments, the 24 h late redistribution imaging detected additional redistribution in 26 segments, taking up 20%. Twenty-four hour late 201 Tl imaging will demonstrated additional redistribution in patients who have incompletely reversible defects on early redistribution imaging at 3 h. (author)

ESPRIT: is aspirin plus dipyridamole superior to aspirin alone in TIA or minor stroke patients?

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Rouhl, R P W; Lodder, J

2008-11-01

Transient ischemic attack (TIA) or a (minor) ischemic stroke increases the risk of a recurrent stroke or death. Antiplatelet therapy with aspirin or clopidogrel is, in the absence of a potential cardiac embolic source, common practice to lower this risk. Until recently, adjuvant dipyridamole or low intensity oral anticoagulation were not generally prescribed in secondary prevention. In this article, we will summarize and discuss the published results of the European/Australasian Stroke Prevention in Reversible Ischemia Trial (ESPRIT). In this trial, treatments with anticoagulants, aspirin alone and the combination of aspirin plus dipyridamole were compared, in a multicenter, three-armed, randomized, open-label study in patients with TIA or minor stroke.

Thallium in fractions of sediments formed during the 2004 tsunami in Thailand.

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Lukaszewski, Zenon; Karbowska, Bozena; Zembrzuski, Wlodzimierz; Siepak, Marcin

2012-06-01

Thallium is a highly toxic element. Its concentration in sediment fractions from the 2004 tsunami in Thailand was investigated. A modified BCR procedure was used for sequential extraction. Tl was determined by flow injection differential pulse anodic stripping voltammetry. It was found that the majority of thallium in the investigated tsunami sediments (86-97 percent) is entrapped in the alumosilicate parent matter i.e. it is entirely immovable. Only the total destruction of this residual fraction with hydrofluoric acid made this thallium available. The conclusion strongly supports the hypothesis that thallium is mainly entrapped in alumosilicate parent matter. Total thallium concentration in the investigated tsunami sediments was divergent in various samples from 0.37 to 1.13 μg g(-1) and significantly different from the reference area (0.05 μg g(-1)). Tsunami sediment fractions from different sampling points are divergent in terms of total thallium concentration and concentration of mobile thallium. Generally, mobile thallium concentration was growing in sequence: water soluble fractionthallium concentration in the reducible fraction was higher than in the oxidizable fraction. Copyright © 2012 Elsevier Inc. All rights reserved.

Quantitative evaluation of right ventricular overload with thallium-201 myocardial perfusion scintigraphy

International Nuclear Information System (INIS)

Watanabe, Toshiya; Miyakoda, Hiroyuki; Koike, Yoshihiro; Itatsu, Hidetaka; Kawai, Naoki; Sotobata, Iwao.

1983-01-01

Thallium-201 myocardial perfusion scintigraphy and right-heart catheterization were performed on patients with right ventricular pressure overload (RVPO) or right ventricular volume overload (RVVO). In 18 patients with RVPO, right ventricular systolic pressure correlated significantly both with the RV/LV wall thallium-201 uptake ratios (r=0.54, p<0.02) and the RV wall/background thallium-201 uptake ratios (r=0.70, p<0.01). RV/LV work ratios also significantly correlated with RV/LV wall thallium-201 uptake ratios (r=0.57, p<0.02). In 19 patients with RVVO, Qp/Qs and RV/LV work ratios both significantly correlated with RV/LV wall thallium-201 uptake ratios (r=0.78 and 0.87, respectively; p<0.001 for both) and RV wall/background thallium-201 uptake ratios (r=0.69, p<0.01 for both parameters). Right ventricular systolic pressure also correlated with RV/LV wall thallium-201 uptake ratios (r=0.57, p<0.02). Feasibility of the differentiation between RVPO and RVVO was suggested with use of ''transitional view angle'' and RV/LV diameter ratios obtained from the scintigram. In patients who underwent cardiac surgery, post-operative alleviations of the right ventricular overload were evaluated. There was a significant decrease in RV/LV wall thallium-201 uptake ratios, but no significant decrease in RV wall/background thallium-201 uptake ratios in patients with RVPO. On the other hand, there was a significant decrease both in RV/LV wall thallium-201 uptake ratios and RV wall/background thallium-201 uptake ratios in patients with RVVO. No significant changes were observed between the scintigraphic measurements obtained 1 month and 1 year after the surgery, irrespective of the type of right ventricular overloading. (J.P.N.)

Rapid gated Thallium-201 perfusion SPECT - clinically feasible?

International Nuclear Information System (INIS)

Wadhwa, S.S.; Mansberg, R.; Fernandes, V.B.; Wilkinson, D.; Abatti, D.

1998-01-01

Full text: Standard dose energy window optimised Thallium-201 (Tl-201) SPECT has about half the counts of a standard dose from Technetium-99m Sestamibi (Tc99m-Mibi) gated perfusion SPECT. This study investigates the clinical feasibility of rapid energy window optimised Tl-201 gated perfusion SPECT (gated-TI) and compares quantitative left ventricular ejection fraction (LVEF) and visually assessed image quality for wall motion and thickening to analogous values obtained from Tc99m-Mibi gated perfusion SPECT (gated - mibi). Methods: We studied 60 patients with a rest gated Tl-201 SPECT (100 MBq, 77KeV peak, 34% window, 20 sec/projection) followed by a post stress gated Sestamibi SPECT (1GBq, 140KeV, 20% window, 20 sec/projection) separate dual isotope protocol. LVEF quantitation was performed using commercially available software (SPECTEF, General Electric). Visual grading of image quality for wall thickening and motion was performed using a three-point scale (excellent, good and poor). Results: LVEF for gated Tl-201 SPECT was 59.6 ± 12.0% (Mean ± SD). LVEF for gated Sestamibi SPECT was 60.4 ±11.4% (Mean ± SD). These were not significantly different (P=0.27, T-Test). There was good correlation (r=0.9) between gated-TI and gated-mibi LVEF values. The quality of gated-Tl images was ranked as excellent, good and poor in 12, 50 and 38% of the patients respectively. Image quality was better in gated-mibi SPECT, with ratings of 12, 62 and 26% respectively. Conclusion: Rapid gated Thallium-201 acquisition with energy window optimisation can be effectively performed on majority of patients and offers the opportunity to assess not only myocardial perfusion and function, as with Technetium based agents, but also viability using a single day one isotope protocol

Diagnostic imaging in liver transplantation. Preoperative evaluation and postoperative complications

International Nuclear Information System (INIS)

Schroeder, T.; Ruehm, S.G.

2005-01-01

Complimentary to orthotopic liver transplantation (OLT), living donor liver transplantation (LDLT) is increasingly considered a therapeutic option in the therapy of end-stage liver disease. Accurate pre- and postoperative imaging is crucial for the transplantation success and represents an established part of the current evaluation algorithms. This article summarizes the most important requirements and the current imaging standards. Preoperative imaging is important for exclusion of transplantation contraindications in the recipient and for reliable assessment of anatomical variants in the donor. The main purpose of postoperative imaging is the early detection and characterization of complications. In both instances, multislice CT currently represents the most versatile and reliable imaging modality, still superior to MRI. For postoperative follow-up, the imaging modality of first choice is still bedside ultrasound; however, unclear findings usually need to be further assessed by CT. (orig.) [de

New Exercise-Dipyridamole Combined Test for Nuclear Cardiology in Insufficient Effort: Appropriate Diagnostic Sensitivity Keeping Exercise Prognosis

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Inés Vidal Cortinas

2015-08-01

Full Text Available AbstractBackground:Myocardial perfusion scintigraphy (MPS in patients not reaching 85% of the maximum predicted heart rate (MPHR has reduced sensitivity.Objectives:In an attempt to maintain diagnostic sensitivity without losing functional exercise data, a new exercise and dipyridamole combined protocol (EDCP was developed. Our aim was to evaluate the feasibility and safety of this protocol and to compare its diagnostic sensitivity against standard exercise and dipyridamole protocols.Methods:In patients not reaching a sufficient exercise (SE test and with no contraindications, 0.56 mg/kg of dipyridamole were IV administered over 1 minute simultaneously with exercise, followed by 99mTc-MIBI injection.Results:Of 155 patients, 41 had MPS with EDCP, 47 had a SE test (≥ 85% MPHR and 67 underwent the dipyridamole alone test (DIP. They all underwent coronary angiography within 3 months. The three stress methods for diagnosis of coronary lesions had their sensitivity compared. For stenosis ≥ 70%, EDCP yielded 97% sensitivity, SE 90% and DIP 95% (p = 0.43. For lesions ≥ 50%, the sensitivities were 94%, 88% and 95%, respectively (p = 0.35. Side effects of EDCP were present in only 12% of the patients, significantly less than with DIP (p < 0.001.Conclusions:The proposed combined protocol is a valid and safe method that yields adequate diagnostic sensitivity, keeping exercise prognostic information in patients unable to reach target heart rate, with fewer side effects than the DIP.

Diagnosis of ischaemic heart disease with thallium-201

Energy Technology Data Exchange (ETDEWEB)

Human, G P [Pretoria Univ. (South Africa). Dept. of Internal Medicine; Dormehl, I [Atomic Energy Board, Pelindaba, Pretoria (South Africa). Life Sciences Div.

1981-04-04

Thallium-201 is very suitable for cardiac imaging because of its physical characteristics and biological behaviour. Perfusion defects caused by ischaemia, necrosis or fibrosis are represented by 'cold spots' on the myocardial scan. In this article we report our experience with this method in the diagnosis of ischaemic heart disease in 117 patients. Excellent correlation was found with clinical, electrocardiographic and angiographic parameters. Both sensitivity and specificity for the diagnosis of ischaemic heart disease were higher with /sup 201/Tl scintigraphy than with existing diagnostic methods.

Resting cardiointegram: correlation with stress thallium perfusion studies

International Nuclear Information System (INIS)

Gould, L.A.; Betzu, R.; Judge, D.; Lee, J.; Taddeo, M.; Yang, D.

1988-01-01

The cardiointegram is a noninvasive technique for the analysis of the electrical signals of the heart obtained by a transformation of the voltage versus time format by a series of integrations. The stress thallium perfusion study is a widely used test for the detection of coronary artery disease. In order to evaluate the correlation between the resting cardiointegram and the stress thallium 201 perfusion study, 20 patients with normal resting electrocardiograms underwent stress thallium tests and resting cardiointegrams. The cardiointegram was determined on two resting complexes of leads I, II, V4, V5, and V6 and called abnormal if five of ten complexes deviated outside a normalized template. There was concordance of the cardiointegram and the thallium study in 16 of 20 patients (80%). The sensitivity for the detection of coronary artery disease was 71%, and the specificity was 80%. The overall accuracy was 74%. Thus in patients with normal electrocardiograms, the cardiointegram is a useful noninvasive test for the detection of coronary artery disease

Effect of exercise position during stress testing on cardiac and pulmonary thallium kinetics and accuracy in evaluating coronary artery disease

International Nuclear Information System (INIS)

Lear, J.L.

1986-01-01

We compared the effects of symptom-limited upright and supine exercise on 201Tl distribution and kinetics in the heart and lungs of 100 consecutive patients. Our analysis was based on data obtained with a digital gamma camera in the 45 degrees left anterior oblique position at 5, 40, 240, and 275 min postadministration of [201Tl]chloride. We found significant differences in the results at the 5- and 40-min intervals; viz, higher cardiac and lower pulmonary thallium activity after upright exercise in 94 subjects at both intervals, and greater variability in total and regional cardiac thallium kinetics after supine exercise. With supine exercise, the relatively low initial cardiac activity, relatively high lung activity, and the greater variability in thallium kinetics combined to make interpretation of quantitative data and cardiac images difficult and less accurate with respect to detection of coronary artery disease. These observations have important implications for the interpreting physician when thallium stress tests are performed in the supine position

Thallium toxicosis in a dog consequent to ingestion of Mycoplasma agar plates.

Science.gov (United States)

Puschner, Birgit; Basso, Marguerite M; Graham, Thomas W

2012-01-01

A 1-year-old dog ingested a mixture of blood agar and Mycoplasma agar plates. The Mycoplasma agar plates contained thallium acetate, which resulted in an estimated minimum dose of 5 mg thallium acetate/kg bodyweight. Clinical signs over the course of 2-3 weeks included vomiting, diarrhea, weight loss, alopecia, dysphonia, ataxia, paresthesia, intension tremors, megaesophagus with subsequent aspiration pneumonia, and several seizure episodes. The dog was treated with intravenous fluids and placement of a gastric feeding tube. Thallium concentrations in hair were 8.2 µg/g in samples taken on day 19, 16.4 µg/g in samples taken 3 months after exposure, 13.4 µg/g in samples taken 5 months after exposure, and nondetectable in samples taken 7 months after exposure. The blood thallium concentration was 190 µg/l on day 19 and nondetec table 3 months after exposure. Megaesophagus and dysphonia continued for 10 months after exposure. This case of thallium poisoning following ingestion of mycoplasma agar plates demonstrates that unusual sources of thallium still exist and suggests that thallium toxicosis should be included in the list of differential diagnoses in dogs presented with megaesophagus, especially if alopecia and other unexplained peripheral neuropathies are present. Hair and blood samples are useful specimens to reach an accurate diagnosis even if taken several weeks post exposure. The postexposure blood and hair thallium concentrations reported in this case are useful data for diagnosticians investigating dogs with potential thallium poisoning.

Thallium and its contents in Remata carbonate rocks

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Kondelová Marcela

1996-09-01

Full Text Available The article presents at first the list of thallium own minerals and its isomorphic content in other minerals, especially in Slovakian ore deposits. This trace element was found in numerous dolomite-rock samples from Remata massif near Handlová. An interesting level of Tl content was analyzed in nonsilicified rocks; the highest content of Tl (and Ag are along the E – W line of disturbance. The presence of thallium in some limonitic aggregates in close Kremnica-gold deposit indicate any continuous relation. Some similarities to type gold deposits Carlin ( USA are discussed, even if no gold and discrete thallium phases were in Remata determined yet.

Presence of thallium in the environment: sources of contaminations, distribution and monitoring methods.

Science.gov (United States)

Karbowska, Bozena

2016-11-01

Thallium is released into the biosphere from both natural and anthropogenic sources. It is generally present in the environment at low levels; however, human activity has greatly increased its content. Atmospheric emission and deposition from industrial sources have resulted in increased concentrations of thallium in the vicinity of mineral smelters and coal-burning facilities. Increased levels of thallium are found in vegetables, fruit and farm animals. Thallium is toxic even at very low concentrations and tends to accumulate in the environment once it enters the food chain. Thallium and thallium-based compounds exhibit higher water solubility compared to other heavy metals. They are therefore also more mobile (e.g. in soil), generally more bioavailable and tend to bioaccumulate in living organisms. The main aim of this review was to summarize the recent data regarding the actual level of thallium content in environmental niches and to elucidate the most significant sources of thallium in the environment. The review also includes an overview of analytical methods, which are commonly applied for determination of thallium in fly ash originating from industrial combustion of coal, in surface and underground waters, in soils and sediments (including soil derived from different parent materials), in plant and animal tissues as well as in human organisms.

[Preoperative imaging/operation planning for liver surgery].

Science.gov (United States)

Schoening, W N; Denecke, T; Neumann, U P

2015-12-01

The currently established standard for planning liver surgery is multistage contrast media-enhanced multidetector computed tomography (CM-CT), which as a rule enables an appropriate resection planning, e.g. a precise identification and localization of primary and secondary liver tumors as well as the anatomical relation to extrahepatic and/or intrahepatic vascular and biliary structures. Furthermore, CM-CT enables the measurement of tumor volume, total liver volume and residual liver volume after resection. Under the condition of normal liver function a residual liver volume of 25 % is nowadays considered sufficient and safe. Recent studies in patients with liver metastases of colorectal cancer showed a clear staging advantage of contrast media-enhanced magnetic resonance imaging (CM-MRI) versus CM-CT. In addition, most recent data showed that the use of liver-specific MRI contrast media further increases the sensitivity and specificity of detection of liver metastases. This imaging technology seems to lead closer to the ideal "one stop shopping" diagnostic tool in preoperative planning of liver resection.

Noninvasive assessment of coronary stenoses by myocardial imaging during pharmacologic coronary vasodilation. VI. Detection of coronary artery disease in human beings with intravenous N-13 ammonia and positron computed tomography

International Nuclear Information System (INIS)

Schelbert, H.R.; Wisenberg, G.; Phelps, M.E.; Gould, K.L.; Henze, E.; Hoffman, E.J.; Gomes, A.; Kuhl, D.E.

1982-01-01

The possibility of detecting mild coronary stenoses with positron computed tomography and nitrogen (N-13) ammonia administered during pharmacologic coronary vasodilation was previously demonstrated in chronically instrumented dogs. The feasibility of using this technique in human beings and its sensitivity in determining the degree and extent of coronary artery disease were examined in 13 young normal healthy volunteers and 32 patients with angiographically documented coronary artery disease. N-13 ammonia was administered intravenously and its distribution in the left ventricular myocardium recorded at rest and during dipyridamole-induced coronary hyperemia. In the 13 volunteers, N-13 activity was homogeneous at rest and during hyperemia, whereas 31 of the 32 patients had regional defects on the hyperemic images not present during rest. All six patients with double, all 10 with triple and 15 of 16 patients with single vessel disease (97 percent) were correctly identified with the technique. Two vessel involvement was correctly identified in five of the six patients with double vessel disease and three vessel disease in six of 10 patients. Of all 58 coronary stenoses, 52 (90 percent) were correctly identified. In a subgroup of 11 patients, the technique was compared with exercise thallium-201 planar images, which were abnormal in 10 (91 percent) whereas N-13 images were abnormal in all 11. Of the 19 stenosed coronary arteries in this subgroup, 11 (58 percent) were correctly identified with thallium-201 and 17 (89 percent) with tomography (p less than 0.01). It is concluded that cross-sectional imaging of the myocardial distribution of N-13 ammonia administered during pharmacologic coronary vasodilation is a highly sensitive and accurate means for noninvasive detection of coronary stenoses in human beings and for estimating the extent of coronary artery disease

Synthesis and characterization of nano-pore thallium (III) ion-imprinted polymer as a new sorbent for separation and preconcentration of thallium.

Science.gov (United States)

Arbab-Zavar, Mohammad Hossien; Chamsaz, Mahmoud; Zohuri, Golamhossien; Darroudi, Abolfazl

2011-01-15

Thallium (III) ion-imprinted polymer (IIP) particles were synthesized by preparing the ternary complex of thallium (III) ions with 5,7-dichloroquinoline-8-ol (DCQ) and 4-vinylpyridine (VP). Thermal copolymerization with methyl methacrylate (functional monomer, MMA) and ethyleneglycoldimethacrylate (cross-linking monomer, EGDMA) was then performed in the presence of acetonitrile (porogen) and 2,2- azobisisobutyronitrile(initiator, AIBN). The imprinted ion was removed from polymer by stirring of the above particles with 5M HNO(3) to obtain the leached IIP particles. Moreover, control polymer (CP) particles were similarly prepared without the thallium (III) ions. The unleached and leached IIP particles were characterized by surface area analysis (BET), X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FT-IR), thermo gravimetric analysis (TGA) and scanning electron microscopy (SEM). The preconcentration of thallium (III) from aqueous solution was studied during rebinding with the leached IIP particles as a function of pH, the weight of the polymer material, the uptake and desorption times, the aqueous phase and the desorption volumes. Electrothermal atomic absorption spectrometry (ETAAS) was employed for determination of thallium in aqueous solution. The limit of detection for the method was 0.02 ng mL(-1), while the relative standard deviation for five replicates was 2.6%. Copyright © 2010 Elsevier B.V. All rights reserved.

Myocardial scintigraphy (thallium-201) and electrocardiography at rest and during exercise in angina pectoris

International Nuclear Information System (INIS)

Minning, E.; Scharf-Bornhofen, E.; Brueggeman, Th.; Chen, T.; Barthel, W.; Bluemchen, G.; Sankt-Josef-Hospital, Oberhausen

1980-01-01

Ecg (at rest and during exercise) was compared to Thallium-201 myocardial perfusion imaging (at rest and after exercise) in 65 patients with coronary heart disease (myocardial infarction in 53 patients) and angina pectoris. These results were compared to coronary angiography and left ventricular angiography. (orig./AJ) [de

Single-cell resolution mapping of neuronal damage in acute focal cerebral ischemia using thallium autometallography.

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Stöber, Franziska; Baldauf, Kathrin; Ziabreva, Iryna; Harhausen, Denise; Zille, Marietta; Neubert, Jenni; Reymann, Klaus G; Scheich, Henning; Dirnagl, Ulrich; Schröder, Ulrich H; Wunder, Andreas; Goldschmidt, Jürgen

2014-01-01

Neuronal damage shortly after onset or after brief episodes of cerebral ischemia has remained difficult to assess with clinical and preclinical imaging techniques as well as with microscopical methods. We here show, in rodent models of middle cerebral artery occlusion (MCAO), that neuronal damage in acute focal cerebral ischemia can be mapped with single-cell resolution using thallium autometallography (TlAMG), a histochemical technique for the detection of the K(+)-probe thallium (Tl(+)) in the brain. We intravenously injected rats and mice with thallium diethyldithiocarbamate (TlDDC), a lipophilic chelate complex that releases Tl(+) after crossing the blood-brain barrier. We found, within the territories of the affected arteries, areas of markedly reduced neuronal Tl(+) uptake in all animals at all time points studied ranging from 15 minutes to 24 hours after MCAO. In large lesions at early time points, areas with neuronal and astrocytic Tl(+) uptake below thresholds of detection were surrounded by putative penumbral zones with preserved but diminished Tl(+) uptake. At 24 hours, the areas of reduced Tl(+)uptake matched with areas delineated by established markers of neuronal damage. The results suggest the use of (201)TlDDC for preclinical and clinical single-photon emission computed tomography (SPECT) imaging of hyperacute alterations in brain K(+) metabolism and prediction of tissue viability in cerebral ischemia.

Value of thyroid scintigraphy using thallium 201

International Nuclear Information System (INIS)

Hermans, J.; Parmentier, S.; Beauduin, M.; Schmitz, A.; Therasse, G.

1986-01-01

The value of thallium-201 scintigraphy in the differential diagnosis of cold thyroid nodules demonstrated on the thyroid scan with technetium-99m was emphasized. From the clinical results it can be deduced that if a cold nodule is positive with thallium-201 the lesion has a high percentage of being a high risk of malignancy. This information might be quite valuable in selecting patients for operation [fr

Redistribution of thallium-201 into right ventricle through collateral circulation

International Nuclear Information System (INIS)

Kataoka, Hajime; Ohkubo, Toshitaka; Takaoka, Shigeru; Ohshige, Tamao; Miyahara, Kenkichi.

1984-01-01

The cases of reversible right ventricular ischemia, which demonstrated redistribution of thallium (Tl)-201 into the right ventricular free wall (RVFW) through collateral channels, were reported. Two cases with complete obstruction in the proximal right coronary artery accompanied by collateral channels (left coronary artery to distal right coronary artery) underwent submaximal exercise stress Tl-201 myocardial imaging. Although the RVFW was not visualized on immediate myocardial images in one or both of the 30 0 and 60 0 left anterior oblique views in each case, three-hour delayed myocardial images showed redistribution of Tl-201 into the RVFW. It was concluded that collateral circulation affects the occurrence of redistribution of Tl-201 into the RVFW. (author)

Mechanisms of thallium-201 myocardial accumulation

International Nuclear Information System (INIS)

Wackers, F.J.Th.; Samson, G.

1980-01-01

The practical advantages of 201 Tl over other suitable myocardial imaging agents such as potassium-43 ( 43 K), rubidium-81 ( 81 Rb), and cesium-129 ( 129 Cs), are its relatively low energy photons which makes it possible to employ high-resolution low-energy collimators and its physical half-life of 73 hr which provides sufficiently long shelf-life for practical clinical imaging. Toxicological considerations do not play a role using 201 Tl as thallous chloride. The concentration of thallous chloride in a dose of 2 mCi of 201 Tl is less than 4μg. The LD 50 of thallous chloride is a factor 10 4 more. The minimal lethal dose in man is reported to be 12 mg/kg. The kinetics of 201 Tl, its tissue distributions and radiation doses are assessed, and the effect of cardiac drugs on thallium-201 uptake are discussed. (Auth.)

The possible protective effects of dipyridamole on ischemic reperfusion injury of priapism

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Ersagun Karaguzel

2016-02-01

Full Text Available ABSTRACT Purpose To investigate the protective effects against ischemia reperfusion injury of dipyridamole in a model of induced priapism in rats. Materials and Methods Twenty-four male Sprague-Dawley rats were divided into four groups, control, P/R, P/R+DMSO and P/R+D. 3ml blood specimens were collected from vena cava inferior in order to determine serum MDA, IMA, TAS, TOS and OSI values, and penile tissue was taken for histopathological examination in control group. Priapism was induced in P/R group. After 1h, priapism was concluded and 30 min reperfusion was performed. In P/R+DMSO group 1ml/kg DMSO was administered intraperitoneally 30 min before reperfusion, while in P/R+D group 10mg/kg dipyridamole was administered intraperitoneally 30 min before reperfusion. Blood and penis specimens were collected after the end of 30 min reperfusion period. Sinusoidal area (µm2, tears in tunica albuginea and injury parameters in sinusoidal endothelium of penis were investigated. Results Histopathological examination revealed no significant changes in term of sinusoidal area. A decrease in tears was observed in P/R+D group compared to P/R group (p0.05. There were no significant differences in MDA and IMA values between groups. A significant increase in TOS and OSI values was observed in P/R+D group compared to P/R group. A significant decrease in TAS levels was observed in P/R+D group compared to the P/R group. Conclusions The administration of dipyridamole before reperfusion in ischemic priapism model has a potential protective effect against histopathological injury of the penis.

Multimodal Imaging Nanoparticles Derived from Hyaluronic Acid for Integrated Preoperative and Intraoperative Cancer Imaging

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William M. Payne

2017-01-01

Full Text Available Surgical resection remains the most promising treatment strategy for many types of cancer. Residual malignant tissue after surgery, a consequence in part due to positive margins, contributes to high mortality and disease recurrence. In this study, multimodal contrast agents for integrated preoperative magnetic resonance imaging (MRI and intraoperative fluorescence image-guided surgery (FIGS are developed. Self-assembled multimodal imaging nanoparticles (SAMINs were developed as a mixed micelle formulation using amphiphilic HA polymers functionalized with either GdDTPA for T1 contrast-enhanced MRI or Cy7.5, a near infrared fluorophore. To evaluate the relationship between MR and fluorescence signal from SAMINs, we employed simulated surgical phantoms that are routinely used to evaluate the depth at which near infrared (NIR imaging agents can be detected by FIGS. Finally, imaging agent efficacy was evaluated in a human breast tumor xenograft model in nude mice, which demonstrated contrast in both fluorescence and magnetic resonance imaging.

Thallium 201 Scintigraphy

Science.gov (United States)

McKillop, James H.

1980-01-01

The radioactive isotope thallium 201 behaves physiologically as a potassium analog, and when injected intravenously accumulates rapidly within the cells of many organs. Uptake of the isotope reflects both regional perfusion and sodium-potassium pump activity. The radionuclide emits 80 keV x-rays which are suitable for scintillation camera imaging. The main clinical application of 201TI scintigraphy has been in myocardial imaging. Abnormal uptake of the isotope results in a cold spot on the myocardial image. In patients with coronary artery disease, the differentiation of ischemic and infarcted myocardium is made by comparing images obtained after injecting the radionuclide at the peak of a maximal exercise test with those obtained after injection at rest. Abnormalities due to ischemia usually are seen only on the stress image whereas fixed defects in both rest and stress studies usually indicate areas of infarction or scarring. Some investigators believe that redistribution images obtained four to six hours after stress injection (without administering further 201TI) give the same information as a separate rest study. The sensitivity of stress imaging for detecting significant coronary disease is of the order of 80 percent to 95 percent, though computer processing of the images may be necessary to achieve the higher figure. The prediction of the extent of coronary disease from 201TI images is less reliable. An abnormal 201TI image is not entirely specific for coronary artery disease and the likelihood of an abnormal image being due to this diagnosis varies according to the clinical circumstances. The main clinical value of 201TI myocardial imaging is likely to be in the noninvasive screening of patients with atypical chest pain or with ambiguous findings on stress electrocardiographic tests. It has also proved useful in studying patients with variant angina or following a coronary bypass operation. It is doubtful whether the technique is clinically helpful in most

Pre-operative imaging of rectal cancer and its impact on surgical performance and treatment outcome.

Science.gov (United States)

Beets-Tan, R G H; Lettinga, T; Beets, G L

2005-08-01

To discuss the ability of pre-operative MRI to have a beneficial effect on surgical performance and treatment outcome in patients with rectal cancer. A description on how MRI can be used as a tool so select patients for differentiated neoadjuvant treatment, how it can be used as an anatomical road map for the resection of locally advanced cases, and how it can serve as a tool for quality assurance of both the surgical procedure and overall patient management. As an illustration the proportion of microscopically complete resections of the period 1993-1997, when there was no routine pre-operative imaging, is compared to that of the period 1998-2002, when pre-operative MR imaging was standardized. The proportion of R0 resections increased from 92.5 to 97% (p=0.08) and the proportion of resections with a lateral tumour free margin of >1mm increased from 84.4 to 92.1% (p=0.03). The incomplete resections in the first period were mainly due to inadequate surgical management of unsuspected advanced or bulky tumours, whereas in the second period insufficient consideration was given to extensive neoadjuvant treatment when the tumour was close to or invading the mesorectal fascia on MR. There are good indications that in our setting pre-operative MR imaging, along with other improvements in rectal cancer management, had a beneficial effect on patient outcome. Audit and discussion of the incomplete resections can lead to an improved operative and perioperative management.

Is there any advantage to the acquisition of 24-hour thallium images, in the presence of persistent perfusion defects at 4 h after reinjection?

International Nuclear Information System (INIS)

Bobba, K.; Botvinick, E.H.; Sciammarella, M.G.; Starsken, N.F.; Zhu, Y.Y.; Lapidus, A.; Dae, M.W.

1998-01-01

We determined the incidence of delayed 24-h reversibility post thallium-201 reinjection and imaging at 4 h, as well as the prognostic and significance of such delayed reversibility. We studied 46 consecutive patients with persistent thallium-201 perfusion or incompletely reversible SPET perfusion defects acquired within 10 min after reinjection performed 4 h after stress. In 38 of 46 patients 24-h images showed no further reversibility beyond the post-reinjection 4-h study (group A). Eight of 46 patients demonstrated reversibility on 24-h imaging (group B). Of these eight, three patients showed no improvement compared with the post-stress images, with a mean perfusion score of the abnormal segments of 1.25±0.50 on the 4-h images, and of 3.00 on the 24-h images. Four patients presented with nine mixed regions. Four of these regions showed an improvement in the mean perfusion score of 2.50±0.58 on 4- and 24-h images. Two of them, with moderate/severe defects, demonstrated complete reversibility at 4-h post-reinjection imaging. In addition, five other regions presented no improvement at 4-h imaging, but showed an improvement in the mean perfusion score from 0.80±0.84 at 4-h to 3.30±0.89 at 24-h imaging. Two of these regions in one patient showed a severe perfusion score of 0 at 4 h, and complete reversibility at 24 hours. Another patient had three severe perfusion defects; two of them redistributed partially at 4 h and completely at 24 h. The remaining segment with a perfusion score of 0 at 4 h, presented complete reversibility at 24 h. Two patients revealed significant reversibility at 24 h in a region that was severely underperfused after post-reinjection imaging at 4 h. Among group B patients, 75% had recent acute ischemic syndrome, compared with only 13% in group A. Among 11 patients with unstable angina, six had evidence of delayed 24-h reversibility, compared with 2 of 35 patients without clinically acute ischemia. On follow-up, there were seven cardiac

Is there any advantage to the acquisition of 24-hour thallium images, in the presence of persistent perfusion defects at 4 h after reinjection?

Energy Technology Data Exchange (ETDEWEB)

Bobba, K.; Botvinick, E.H.; Sciammarella, M.G.; Starsken, N.F.; Zhu, Y.Y.; Lapidus, A.; Dae, M.W. [Nuclear Medicine Section, Department of Radiology, Cardiovascular Division, Department of Medicine, and the Cardiovascular Research Institute, University of California, San Francisco (United States)

1998-05-01

We determined the incidence of delayed 24-h reversibility post thallium-201 reinjection and imaging at 4 h, as well as the prognostic and significance of such delayed reversibility. We studied 46 consecutive patients with persistent thallium-201 perfusion or incompletely reversible SPET perfusion defects acquired within 10 min after reinjection performed 4 h after stress. In 38 of 46 patients 24-h images showed no further reversibility beyond the post-reinjection 4-h study (group A). Eight of 46 patients demonstrated reversibility on 24-h imaging (group B). Of these eight, three patients showed no improvement compared with the post-stress images, with a mean perfusion score of the abnormal segments of 1.25{+-}0.50 on the 4-h images, and of 3.00 on the 24-h images. Four patients presented with nine mixed regions. Four of these regions showed an improvement in the mean perfusion score of 2.50{+-}0.58 on 4- and 24-h images. Two of them, with moderate/severe defects, demonstrated complete reversibility at 4-h post-reinjection imaging. In addition, five other regions presented no improvement at 4-h imaging, but showed an improvement in the mean perfusion score from 0.80{+-}0.84 at 4-h to 3.30{+-}0.89 at 24-h imaging. Two of these regions in one patient showed a severe perfusion score of 0 at 4 h, and complete reversibility at 24 hours. Another patient had three severe perfusion defects; two of them redistributed partially at 4 h and completely at 24 h. The remaining segment with a perfusion score of 0 at 4 h, presented complete reversibility at 24 h. Two patients revealed significant reversibility at 24 h in a region that was severely underperfused after post-reinjection imaging at 4 h. Among group B patients, 75% had recent acute ischemic syndrome, compared with only 13% in group A. Among 11 patients with unstable angina, six had evidence of delayed 24-h reversibility, compared with 2 of 35 patients without clinically acute ischemia. On follow-up, there were seven

Distributions and concentrations of thallium in Korean soils determined by single and sequential extraction procedures.

Science.gov (United States)

Lee, Jin-Ho; Kim, Dong-Jin; Ahn, Byung-Koo

2015-06-01

The objectives of this study were to investigate the distribution of thallium in soils collected near suspected areas such as cement plants, active and closed mines, and smelters and to examine the extraction of thallium in the soils using 19 single chemical and sequential chemical extraction procedures. Thallium concentrations in soils near cement plants were distributed between 1.20 and 12.91 mg kg(-1). However, soils near mines and smelters contained relatively low thallium concentrations ranging from 0.18 to 1.09 mg kg(-1). Thallium extractability with 19 single chemical extractants from selected soils near cement plants ranged from 0.10% to 8.20% of the total thallium concentration. In particular, 1.0 M NH4Cl, 1.0 M (NH4)2SO4, and 1.0 M CH3COONH4 extracted more thallium than other extractants. Sequential fractionation results of thallium from different soils such as industrially and artificially contaminated soils varied with the soil properties, especially soil pH and the duration of thallium contamination.

Myocardial kinetics of thallium-201 after stress in normal and perfusion-reduced canine myocardium

International Nuclear Information System (INIS)

Okada, R.D.

1985-01-01

Despite the emerging use of quantitative computer programs for assessing myocardial thallium uptake and clearance after exercise, little is known about the kinetics of thallium after exercise stress. Accordingly, 11 mongrel dogs with experimental left anterior descending coronary stenoses were given thallium during norepinephrine infusion to simulate exercise. The infusion was discontinued and thallium activity was monitored regionally using miniature radiation detectors for 3 hours. Heart rate, arterial pressure and double product all increased significantly during norepinephrine infusion. The mean fractional myocardial thallium clearance was lower (0.47 +/- 0.03 [+/- standard error of the mean]) for the stenosis zone than for the no-stenosis zone (0.57 +/- 0.03) (p less than 0.0001). The stress blood flow ratio (stenosis/no-stenosis zone = 0.27 +/- 0.06) was significantly lower than the final thallium activity ratio (0.68 +/- 0.07) (p less than 0.001), consistent with thallium redistribution occurring over the 3-hour period. Myocardial thallium activity in the stenosis zone peaked in a mean of 2.2 minutes, then washed out biexponentially with a final decay constant of 0.0035 +/- 0.0005 min-1. Myocardial thallium activity in the no-stenosis zone peaked within 1 minute in all dogs, then washed out biexponentially, with a final decay constant of 0.0043 +/- 0.0003 (p less than 0.001 compared with stenosis zone). In conclusion, fractional clearance of thallium can differentiate myocardium distal to a coronary artery stenosis from that supplied by a normal coronary vessel

Enhanced ex vivo inhibition of platelet function following addition of dipyridamole to aspirin after transient ischaemic attack or ischaemic stroke: first results from the TRinity AntiPlatelet responsiveness (TrAP) study.

LENUS (Irish Health Repository)

Tobin, William Oliver

2012-02-01

Ex vivo dipyridamole \\'non-responsiveness\\' has not been extensively studied in ischaemic cerebrovascular disease. Platelet surface marker expression, leucocyte-platelet complex formation and inhibition of platelet function at high shear stress as detected by the PFA-100(R) Collagen-Adenosine-diphosphate (C-ADP) and Collagen-Epinephrine cartridges was assessed in 52 patients within 4 weeks of transient ischaemic attack (TIA) or ischaemic stroke on aspirin, and then 14 d (14 d) and >90 d (90 d) after adding dipyridamole. A novel definition of \\'Dipyridamole non-responsiveness\\' was used. The median C-ADP closure time increased following addition of dipyridamole, remained elevated at 90 d (P <\\/= 0.03), and was unaffected by aspirin dose. 59% at 14 d and 56% at 90 d were \\'dipyridamole non-responders\\' on the PFA-100. The proportion of non-responders at 14 and 90 d was similar (P= 0.9). Compared with baseline (4.6%), median monocyte-platelet complexes increased at 14 d (5.0%, P= 0.03) and 90 d (4.9%, P= 0.04). Low C-ADP closure times were associated with increased monocyte-platelet complexes at 14 d (r= -0.32, P= 0.02) and 90 d (r= -0.33, P = 0.02). Monocyte-platelet complexes increased in the subgroup of dipyridamole non-responders on the PFA-100 (P<\\/= 0.045), but not in responders (P >\\/= 0.5), at 14 and 90 d versus baseline. Additional inhibition of platelet function has been detected with the PFA-100 when dipyridamole is added to aspirin. Elevated monocyte-platelet complexes may contribute to ex vivo dipyridamole non-responsiveness.

[Thallium content in adults older than 45 ages at Hezhang County of Guizhou Province].

Science.gov (United States)

Zhang, Wenli; Yao, Dancheng; Feng, Jiali; Zeng, Dong; Fan, Di; Shang, Qi

2011-05-01

To investigate the feature of Thallium content in adults of heavy metal contaminated district due to mining of Hezhang County, Guizhou Province. METHODS The subjects older than 45 ages were randomly recruited from the mineralized district (Magu village) and no-mineralized district (Salaxi viillage) , urine of villagers were collected and thallium content in urine were detected with ICP-MS. The average thallium contents in urine of Magu villagers were higner than those of Salaxi villagers,The urinary thallium contents of female were higner than those of male. The urinary thallium contents of residents in two districts were mostly under the upper limit of exposure in human bodies. There was no villager suffered from chronic poisoning of thallium in the two observing districts, the 95% upper limits of urinary thallium content for nonoccupational women older than 45 ages in Magu village was 8 microg/gCr and those for other nonoccupational subjects older than 45 ages was 5 microg/gCr.

Management of thallium poisoning in patients with delayed hospital admission.

Science.gov (United States)

Sun, Tong-Wen; Xu, Qing-Yan; Zhang, Xiao-Juan; Wu, Qiong; Liu, Zhang-Suo; Kan, Quan-Cheng; Sun, Cheng-Ye; Wang, Lexin

2012-01-01

To describe the clinical features and management of thallium poisoning in patients with delayed hospital admission. Fourteen patients (median age 36 years) were admitted 9-19 days after ingesting food poisoned with thallium. Clinical and laboratory data, including blood and urine thallium concentrations, were collected. Patients were treated with oral Prussian blue, a chelating agent sodium dimercaptosulfonate, and hemodialysis. All patients experienced a triad of symptoms of acute gastrointestinal upset, painful combined polyneuropathy, and hair loss after consuming poisoned food. Fatigue and skin pigmentation were observed in all patients. Abnormal liver function tests were found in 6 (42.9%) and delirium and coma were identified in 4 (28.6%). Two weeks after the poisoning, the blood and urine thallium concentration ranged from 219.0 to 1414.4 μg/L (median: 535.3) and 956.5 to 11285.0 μg/L (median: 7460.0), respectively. One patient (7.1%) with a previous history of pulmonary fibrosis died of respiratory failure in hospital. Symptoms were improved and blood or urine thallium levels were normalized in the remaining 13 patients before discharge. After a 6.5 ± 1-month follow-up, 1 patient (7.1%) developed deep venous thrombosis in the left lower limb. In another patient (7.1%), numbness in the lower limbs remained. Acute thallium poisoning is commonly manifested by gastrointestinal upset, painful polyneuropathy, and significant hair loss. Treatment strategies included Prussian blue and hemodialysis, which were associated with a good outcome in this case series.

Dose titration to reduce dipyridamole-related headache.

Science.gov (United States)

Chang, Yeu-Jhy; Ryu, Shan-Jin; Lee, Tsong-Hai

2006-01-01

Combination of low-dose aspirin and modified-release dipyridamole (ASA+MR-DP) provides a significantly increased benefit in stroke prevention over aspirin alone. However, headaches were reported in more patients receiving dipyridamole-containing agents than in those receiving placebo. We undertook a randomized, double-blind, placebo-controlled trial to evaluate which dosing regimens of ASA+MR-DP have better tolerance. This trial randomized 146 patients with a history of ischemic cerebrovascular disease into three groups: placebo (days 1-28), reduced dose (placebo on days 1-4, ASA+MR-DP once daily before bed during days 5-14, and b.i.d. on days 15-28), and regular dose (placebo on days 1-4, and ASA+MR-DP b.i.d. on days 5-28). Using Chinese diary card, headache was assessed as mean cumulated headache (Sigma frequency x intensity/occurrence days x study days) over the study period, and was graded 0-4 according to Cancer Therapy Evaluation Program, Common Toxicity Criteria, Version 2.0. Intent-to-treat patients after randomization was 46 in placebo group, 45, reduced dose, and 49, regular dose. Among commonly reported adverse effects, headache of any grade occurred significantly more in the regular dose group (38.8%), as compared to the other two groups (p < 0.05). Mean cumulated headache was higher (p < 0.05) in the regular dose group than in the reduced group during days 5-14. Of 27 patients who dropped out, 15 (55.6%) were due to headache, which was substantially more in regular dose (8, 53.3%), though the difference was statistically insignificant. Initial reduced dose treatment with ASA+MR-DP may cause fewer headaches than regular dosing, and seems better tolerated by those susceptible to phosphodiesterase inhibitor-induced headache. Copyright 2006 S. Karger AG, Basel.

Quantitative comparison of technetium-99m tetrofosmin and thallium-201 images of the thyroid and abnormal parathyroid glands

International Nuclear Information System (INIS)

Giordano, A.; Meduri, G.; Calcagni, M.L.; Marozzi, P.; Ficola, U.; Vaccaro, A.; Rubini, G.; Attard, M.; Li Puma, M.; Ricci, R.; Corsello, S.

1999-01-01

The aim of the study was to quantitatively compare the scintigraphic images of the thyroid and abnormal parathyroid glands obtained with technetium-99m tetrofosmin and thallium-201 in patients with hyperparathyroidism. Forty-six patients with hyperparathyroidism underwent 201 Tl (74 MBq), 99m Tc-pertechnetate (74 MBq) and 99m Tc-tetrofosmin (555-740 MBq) scintigraphy in a single session. Image analysis included the computation of the thyroid/background ratio in the whole study population and the parathyroid/background ratio, parathyroid/thyroid ratio and diagnostic sensitivity in 17 patients who underwent parathyroid surgery. The pertechnetate subtraction technique was used. 201 Tl and 99m Tc-tetrofosmin showed a similar thyroid/background ratio (1.79±0.41 and 1.81±0.47, respectively, P=NS); however, 99m Tc-tetrofosmin showed a higher parathyroid/background ratio than 201 Tl (2.06±0.54 vs 1.79± 0.50, P=0.007). Despite the superior quality of 99m Tc-tetrofosmin images, both tracers showed identical sensitivity in detecting enlarged parathyroid glands in patients with primary hyperparathyroidism (89%) and in those with secondary hyperparathyroidism (50%). (orig.)

The significance of a dipyridamole induced [sup 99m]Tc-MIBI perfusion abnormality on single photon emission tomography: A quantiative validation with labelled water and positron emission tomography

Energy Technology Data Exchange (ETDEWEB)

Rechavia, E.; Galassi, A.R.; Araujo, L.I.; Halson, P.; Lammertsma, A.; Jones, T.; Lavender, J.P.; Maseri, A. (Royal Postgraduate Medical School, London (United Kingdom). Nuclear Medicine Dept. Medical Research Council, London (United Kingdom). Cyclotron Unit Medical Research Council, London (United Kingdom). Cardiovascular Unit)

1992-12-01

To relate [sup 99m]Tc-MIBI uptake to regional myocardial blood flow (rMBF), [sup 99m]Tc-MIBI SPET and H[sub 2] [sup 15]O PET scans were obtained at rest and after dipyridamole infusion in six patients with single vessel coronary artery disease. [sup 99m]Tc-MIBI-H[sub 2] [sup 15]O data sets were created for each segment perfused by the stenotic vessel and for a normal reference area, assigning regions on the SPET tomograms to comparable regions on the PET by similar transaxial image reconstructions. All patients demonstrated post-dipyridamole [sup 99m]Tc-MIBI perfusion defects in the territories supplied by the stenotic arteries; Resting rMBF in these regions was slightly lower than that in the normal areas. A 43% [+-] 14% reduction in [sup 99m]Tc-MIBI activity in the area at risk was coupled with on average a 60% [+-] 9% reduction in post-dipyridamole rMBF compared with control regions. Thus, SPET assessment of [sup 99m]Tc-MIBI uptake tends to underestimate the perfusion contrast between areas with normal and areas with low coronary vasodilatory reserve when compared to PET. However, these findings may still not affect the clinical usefulness of [sup 99m]Tc-MIBI and more extensive studies are required to confirm these results in the clinical environment (orig./MG).

Assessment of ischemic heart disease by dipyridamole stress electrocardiographic gated myocardial single photon emission computed tomography with technetium-99m tetrofosmin

International Nuclear Information System (INIS)

Kanna, Masahiko; Mitani, Isao; Nakamaru, Masashi; Shibuya, Ken; Takeda, Kazuyoshi; Asahina, Shigeru; Kitamura, Yutaka; Higuma, Kikuhiko; Ishii, Masao

1998-01-01

Simultaneous assessment of stress perfusion and rest function is possible with gated single photon emission computed tomography (SPECT) using stress injected technetium-99m ( 99m Tc) tetrofosmin (TF). The feasibility of dipyridamole stress electrocardiographic gated myocardial SPECT (GSPECT) with TF was examined as an alternative to conventional stress/rest imaging. Fifty-one patients underwent stress GSPECT. 740 MBq of TF was administered 3 min after dipyridamole infusion. GSPECT acquisition was performed one hour after the injection. Additional rest SPECT was performed on another day only in patients with abnormal perfusion on stress images. Perfusion and thickening were analyzed visually on 17 segments of the left ventricle. Percentage of wall thickening (%WT) was also calculated in 17 segments of the polar map. Thirty-two of 51 patients (63%) had normal stress perfusion and normal rest thickening. Nineteen of 51 patients (37%) had abnormal perfusion on stress images. Among 157 abnormal perfusion segments of the 19 patients, 139 segments (89%) had thickening and the rest (11%) had no thickening. %WT was higher in the reversible segments with or without thickening. There was better agreement for the identification of normal segments and the presence of reversibility between stress GSPECT and the conventional stress/rest study in patients without previous myocardial infarction than in those with previous myocardial infarction (89% vs 79%). These results suggest that stress GSPECT may substitute for conventional stress/rest perfusion study in patients without previous myocardial infarction, allowing shorter examination time and lower cost. However, stress GSPECT does not replace the need for rest perfusion study in patients with previous myocardial infarction, because of underestimation of viability, but %WT may eliminate this underestimation. (author)

Comparative analysis of the diagnostic and prognostic value of exercise ECG and thallium-201 scintigraphic markers of myocardial ischemia in asymptomatic and symptomatic patients