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PubMed1996

Hemodynamic indices of myocardial dysfunction correlate with dipyridamole thallium-201 SPECT.

UNLABELLED: Important differences in hemodynamics and tracer kinetics occur with dipyridamole compared to exercise scintigraphy. To better understand the clinical significance of dipyridamole SPECT 201Tl scintigraphy, we examined the relationships between scintigraphy and clinical, and angiographic and hemodynamic variables in patients with CAD. METHODS: Forty-nine subjects were divided into three study groups. Patients in Groups A (n = 11) and B (n = 20) had a low (<5%) likelihood of CAD. Group A underwent maximal exercise thallium stress testing. Group B underwent thallium dipyridamole scintigraphy. Group C (n = 18) consisted of patients with coronary artery disease who had dipyridamole thallium scintigraphy and cardiac catheterization within 2 wk. Thallium lung-to-myocardial ratio (L/M), left ventricular dilation and perfusion defect site were compared to hemodynamic, clinical and angiographic variables. RESULTS: The Group A L/M ratio of 0.23 +/- 0.05 (mean +/- 1 s.d.) was significantly lower (p < 0.001) compared to the Group B L/M ratio of 0.31 +/- 0.05. In Group C, the UM ratio showed correlation with indices of left ventricular dysfunction including lower resting ejection fraction (p = 0.02, r = 0.83), higher pulmonary capillary wedge pressure (p = 0.01, r = 0.58) and lower cardiac index (p = 0.03, r = 0.54). Left ventricular dilation was associated with hemodynamic changes of ventricular failure including lower resting ejection fraction (p = 0.008, r = 0.88) and higher pulmonary capillary wedge pressure (p = 0.02, r =0.54). Immediate and delayed perfusion defect size showed good correlation with lower resting left ventricular ejection fraction (p = 0.02, r = 0.83, and p = 0.004, r = 0.91, respectively). CONCLUSION: Lung uptake, left ventricular dilation and perfusion defect size show good correlation to hemodynamic indices of resting left ventricular dysfunction. A combination of these factors may be a better predictor of future cardiac events and prognosis.

Cardiac Catheterization↗
PubMed1997

One-year effect of myocardial revascularization on resting left ventricular function and regional thallium uptake in chronic CAD.

UNLABELLED: It is still unclear whether in patients with chronic coronary artery disease (CAD) the improvements in myocardial perfusion and left ventricular (LV) function induced by revascularization persist in the long run. This study was planned to evaluate the 1-yr effects of successful revascularization on myocardial perfusion and LV function in patients with CAD and to assess the accuracy of thallium imaging in the prediction of functional recovery 1 yr after revascularization. METHODS: Thirty-eight patients with chronic CAD who were revascularized (experimental group) underwent, while off drugs, 201Tl tomography, two-dimensional echocardiography and radionuclide angiography before and after a 1-yr follow-up. Twenty-nine patients with similar characteristics who were not revascularized (control group) and completed the 1-yr follow-up were also studied. Regional thallium activity was quantitatively measured in 13 segments per patient. Systolic function was assessed by echocardiography in corresponding segments. RESULTS: In the experimental group, at baseline, on the basis of regional LV function and thallium uptake, 276 segments were normal, 169 dysfunctional-viable and 49 nonviable. After revascularization, the majority (75%) of the dysfunctional-viable segments at baseline showed functional recovery at follow-up, whereas the majority (81%) of the nonviable segments at baseline did not. Simultaneously, LV ejection fraction increased 4 wk after revascularization (from 39% +/- 9% to 42% +/- 10%, p < 0.01) and remained unchanged after 1-yr (43% +/- 8%, p < 0.01 versus baseline study). LV wall-motion score index after 1 yr was reduced (from 1.68 +/- 0.4 to 1.42 +/- 0.3, p < 0.001) as compared with baseline. On the contrary, in the control group, no change in myocardial perfusion and LV function was detected after the 1-yr follow-up. CONCLUSION: In patients with chronic CAD, successful coronary revascularization induces a stable improvement in myocardial perfusion and LV function, which is still detectable after a 1-yr follow-up. Furthermore, preserved thallium uptake in dysfunctional regions is predictive of functional recovery after revascularization.

Angioplasty, Balloon, Coronary↗
PubMed1991

Single-photon emission computed tomographic thallium imaging with adenosine, dipyridamole, and exercise.

Stress thallium imaging is a sensitive technique for detecting coronary artery disease, particularly in those patients with multivessel disease. Single-photon emission computed tomography (SPECT) is superior to planar imaging; because of improved image quality and lack of overlap between normal and abnormal segments, SPECT has greater ability to detect diseased arteries. The inherent three-dimensional nature of the data presentation suggests the feasibility of quantifying the extent of myocardium at risk. Pharmacologic stressors such as adenosine and dipyridamole allow imaging with thallium (and probably other perfusion agents) even in patients who are not candidates for exercise testing or who cannot achieve adequate levels of exercise. Studies suggest that adenosine has unique advantages for use with SPECT perfusion imaging with a high degree of accuracy. In our experience the sensitivity of detecting one-vessel disease is higher with adenosine-thallium imaging than in exercise SPECT thallium imaging. The degree of coronary hyperemia is greater and the duration of action is shorter with adenosine than with dipyridamole.

Adenosine↗
PubMed1980

Merits of stress thallium-201 myocardial perfusion imaging in patients with inconclusive exercise electrocardiograms: correlation with coronary arteriograms.

Stress thallium-201 myocardial perfusion images were obtained in 65 patients with an inconclusive exercise electrocardiogram. All 65 patients underwent coronary angiograpic studies. The exercise electrocardiogram was judged inconclusive in 35 patients (54 percent) because submaximal exercise had been performed and in 30 patients (46 percent) who manifested ST-T segment abnormalities at rest. Exercise thallium-201 myocardial perfusion images were abnormal in 20 patients and normal in 45. Nineteen (95 percent) of the 20 patients with abnormal exercise images had severe disease of one or more major coronary arteries. Thirty-seven (82 percent) of the 45 patients with normal exercise images had no significant coronary artery disease; the remaining 8 patients had coronary artery disease. Therefore, 19 of 27 patients with coronary artery disease had abnormal exercise images (sensitivity 70 percent), and 37 of 38 patients without coronary artery disease had normal exercise images (specificity 97 percent). Thallium-201 imaging predicted the correct diagnosis in 56 patients (86 percent). Thus, exercise myocardial imaging with thallium-201 appears to be a useful diagnostic aid in patients with an inconclusive exercise electrocardiogram.

Adult↗
PubMed2003

Colistin sulfate as a suitable substitute of thallium acetate in culture media intended for mycoplasma detection and culture.

Thallium acetate in concentrations of 500 to 1000 mg/l is tolerated in the culture by the most mollicutes of the orders Mycoplasmatales and Acholeplasmatales and by this reason it is added in the culture media as a selective element for the detection and propagation of mycoplasmas and acholeplasmas. Because of the high toxicity of thallium acetate and its accumulation in the environment, thallium acetate is not biodegradable, an alternative was searched. The results and analysis of tests with nine mollicute species are presented here. It is recommended to replace thallium acetate in the formulations where it is used and colistin sulfate is proposed as its substitute.

Acholeplasma laidlawii↗
PubMed2004

Modification of binuclear Pt-Tl bonded complexes by attaching bipyridine ligands to the thallium site.

Complex formation of monomeric thallium(III) species with 2,2'-bipyridine (bipy) in dimethyl sulfoxide (dmso) and acetonitrile solutions was studied by means of multinuclear ((1)H, (13)C, and (205)Tl) NMR spectroscopy. For the first time, NMR signals of the individual species [Tl(bipy)(m)(solv)](3+) (m = 1-3) were observed despite intensive ligand and solvent exchange processes. The tris(bipy) complex was crystallized as [Tl(bipy)(3)(dmso)](ClO(4))(3)(dmso)(2) (1), and its crystal structure determined. In this compound, thallium is seven-coordinated; it is bonded to six nitrogen atoms of the three bipy molecules and to an oxygen atom of dmso. Metal-metal bonded binuclear complexes [(NC)(5)Pt-Tl(CN)(n)(solv)](n)(-) (n = 0-3) have been modified by attaching bipy molecules to the thallium atom. A reaction between [(NC)(5)Pt-Tl(dmso)(4)](s) and 2,2'-bipyridine in dimethyl sulfoxide solution results in the formation of a new complex, [(NC)(5)Pt-Tl(bipy)(solv)]. The presence of a direct Pt-Tl bond in the complex is convincingly confirmed by a very strong one-bond (195)Pt-(205)Tl spin-spin coupling ((1)J((195)Pt-(205)Tl) = 64.9 kHz) detected in both (195)Pt and (205)Tl NMR spectra. In solutions containing free cyanide, coordination of CN(-) to the thallium atom occurs, and the complex [(NC)(5)Pt-Tl(bipy)(CN)(solv)](-) ((1)J((195)Pt-(205)Tl) = 50.1 kHz) is formed as well. Two metal-metal bonded compounds containing bipy as a ligand were crystallized and their structures determined by X-ray diffractometry: [(NC)(5)Pt-Tl(bipy)(dmso)(3)] (2) and [(NC)(5)Pt-Tl(bipy)(2)] (3). The Pt-Tl bonding distances in the compounds, 2.6187(7) and 2.6117(5) A, respectively, are among the shortest reported separations between these two metals. The corresponding force constants in the molecules, 1.38 and 1.68 N/cm, respectively, were calculated using Raman stretching frequencies of the Pt-Tl vibrations and are characteristic for a single metal-metal bond. Electronic absorption spectra were recorded for the [(NC)(5)Pt-Tl(bipy)(m)(solv)] compounds, and the optical transition was attributed to the metal-metal bond assigned.

Journal Article↗
PubMed2006

Historical pollution of seldom monitored trace elements in Sweden--Part B: sediment analysis of silver, antimony, thallium and indium.

Sediment cores from four boreal and remote lakes in a south to north transect in central Sweden were analysed for acid leachable silver, antimony, thallium and indium in the solid sediment phase and the corresponding porewater. Dating of the cores was made by their content of acid leachable lead and the (206)Pb/(207)Pb ratio, in one lake also by (210)Pb. The impact of diagenesis on element redistribution in the sediments was included and found to be minor except for thallium. The results show lowered concentrations towards the north and most intense accumulation after the Second World War, which is taken as evidence for atmospheric deposition being the primary source. Indium has declining concentrations in recent strata while silver and antimony increase. Thallium has lowered acid-leachable concentrations in recent strata. For all metals the impact of domestic industrialisation as well as the early industrialisation of central Europe is discernible. Only thallium appears to reach a geological background at depths that correspond to the late 18th century. For the other metals elevated levels are concluded.

Environmental Monitoring↗
PubMed2000

The value of dipyridamole thallium scintigraphy and dobutamine stress echocardiography as predictors of cardiac complications following reconstruction of the abdominal aorta.

BACKGROUND: The aim of this study was to evaluate the ability of dipyridamole thallium scintigraphy and dobutamine stress echocardiography to predict cardiac complications following elective reconstruction of the abdominal aorta in patients with a stable preoperative cardiac condition and to compare this with information obtained from the medical history, ECG and resting echocardiography alone. METHODS: This evaluation was performed from January 1993 until December 1995 as part of a prospective, randomised study in 200 patients, with a mean age of 65 (5% women). Dipyridamole thallium scintigraphy was performed on 195 patients and dobutamine stress echocardiography was added to the protocol in the last 83 patients. Cardiac complications were defined before the start of the study. RESULTS: In the postoperative period 62 cardiac complications occurred (31%). In patients clinically suspected of having coronary artery disease the incidence of complications was 40% (51/126), compared to 15% (11/74) when no coronary pathology was suspected (p<0.001). When reversible defects were present on dipyridamole thallium scintigraphy the incidence of complications was 36% (20/55), compared to 29% (41/140) when no reversible defects had been found (NS). Dobutamine stress echocardiography was impossible or contraindicated in 21 patients. In the remaining patients the incidence of complications was 71% (5/7) when new regional wall motion abnormalities were found, compared to 16% (9/55) when such abnormalities had not been detected (p<0.005). CONCLUSIONS: These data suggest that cardiac complications following reconstruction of the abdominal aorta in patients with a stable cardiac condition are best predicted by dobutamine stress echocardiography. Dipyridamole thallium scintigraphy, however, does not seem to be useful in this respect.

Aged↗
PubMed1990

Thallium-201 scintigraphy in the diagnosis and management of myocardial sarcoidosis.

We have described three patients with clinical evidence of myocardial sarcoidosis to illustrate the utility of thallium-201 scintigraphy in demonstrating the myocardial lesions. Both the symptomatic and asymptomatic individuals studied showed the characteristic "reverse redistribution" phenomenon. No abnormalities were seen during the exercise phase of the thallium study, but myocardial defects were detected in each patient when repeat studies were obtained at rest six hours later. Steroid therapy resolved the defects in each case. We propose thallium-201 scintigraphy of the heart as a safe and useful tool for documenting myocardial involvement in sarcoidosis and following the effects of therapy.

Adrenal Cortex Hormones↗
PubMed1989

[Comparison of myocardial thallium and beta-methyl iodophenyl pentadecanoic acid (BMIPP) distribution in the cardiomyopathic hamster].

The usefulness of fatty acid imaging in the detection of cardiomyopathy was evaluated by comparing thallium and BMIPP myocardial distribution in Bio 14.6 Syrian Hamster (25 week ages). Autoradiography was performed in 3 using 3.7 MBq (100 microCi) of 125I-BMIPP and 37 MBq (1 mCi) of 201TlCl. In vivo pin-hole imaging was performed in 3 using 37 MBq (1 mCi) of 123I-BMIPP and 37 MBq (1 mCi) of 201TlCl. In all cardiomyopathic hamsters decreased uptake of BMIPP compared to that of thallium was demonstrated. These findings suggest dilated cardiomyopathy is associated with severe focal alteration in the substrate used for the performance of myocardial work. In conclusion, myocardial imaging using BMIPP may be useful for early detection of myocardial degeneration compared to thallium in patients with dilated cardiomyopathy.

Animals↗
PubMed1994

Comparison of thallium-201 and F-18 FDG SPECT uptake in squamous cell carcinoma of the head and neck.

PURPOSE: To compare the uptake of 2-[F-18] fluoro-2-deoxy-D-glucose (fludeoxyglucose F-18; F-18 FDG) and thallous chloride Tl 201, using single-photon emission CT (SPECT), for the detection and location of squamous cell carcinoma of the head and neck. METHODS: Five patients with biopsy-proved squamous cell carcinoma of the upper aerodigestive tract underwent both F-18 FDG and thallium-201 SPECT on the same day. F-18 FDG SPECT was performed using a dual-head gamma camera equipped with commercially available, extremely high-energy collimators (full width half-maximal height, 17 mm for 511 keV photons). Tumor size was estimated at 1.0 to 5.0 cm3 in these cases. RESULTS: F-18 FDG SPECT showed five of five primary tumors. In two of the five cases, normal salivary gland activity severely limited thallium SPECT, and the tumors could not be definitively identified. Two of four lymph node groups that were positive for metastatic disease by CT criteria were shown by F-18 FDG SPECT. None were seen with thallium imaging. In one case, F-18 FDG SPECT was able to show a tumor that was not visible on CT. CONCLUSIONS: F-18 FDG has advantages over Tl-201 as a squamous cell carcinoma imaging agent (primarily because of its reduced salivary activity). F-18 FDG SPECT has potential as a viable, less expensive alternative to F-18 FDG positron emission tomography. The ultimate value of F-18 FDG SPECT imaging for detecting occult malignancy, monitoring therapeutic effectiveness, or evaluating tumor recurrence remains to be determined in patients with squamous cell carcinoma of the head and neck.

Biopsy↗
PubMedDate not supplied

Flotation separation and electrothermal atomic absorption spectrometric determination of thallium in wastewater samples.

The proposed method is a simple process for the determination of trace amount of thallium(I) in the environmental wastewater samples by electrothermal atomic absorption spectrometry. The wastewater samples were obtained from the environment of a cement plant and subjected to a simple treatment, such as adjusting pH and masking the interfering ions, to prepare for the flotation process in which the thallium(I) content was floated as an ion-association complex using iodide and Rhodamine B at the interface of aqueous/cyclohexane layers. The floated layer was then separated and dissolved in 2 ml of a solution, which was 1% to H2SO4 and 50% to methanol, respectively. Aliquots of 10-microl of this solution were subjected to the graphite furnace to determine the thallium(I) content. The flotation process can be carried in a weak acidic medium in which the interfering effects owing to certain metal ions were eliminated by masking them as neutral citrate chelates. The dynamic range for the determination was found to be 1.0 x 10(-8) - 1.0 x 10(-7) mol l(-1). The RSD was 3.2% and the DL was 2.5 x 10(-9) mol l(-1) (calculated as 3SD of the blank). The reliability of the method is demonstrated by the analysis of a synthetic wastewater in which the recovery was found to be 94%.

Chelating Agents↗
PubMed1983

Noninvasive ergonovine maleate provocative testing for coronary artery spasm: the need for routine thallium-201 imaging.

We administered ergonovine and used both electrocardiographic monitoring and thallium-201 [201Tl] imaging to detect reversible ischemia in 100 patients. Patients already established as having coronary artery spasm and those with nonbypassed, proximal, high-grade coronary artery stenosis were excluded. No complication occurred in any patient. The use of thallium imaging in addition to electrocardiographic monitoring resulted in a higher degree of sensitivity than did ECG monitoring alone. Fourteen patients demonstrated evidence of coronary artery spasm as documented by 201Tl imaging but of the 14, significant ECG changes occurred in only 50%, and classic ST segment elevation in 21%. Thus, in carefully selected patients the noninvasive provocation of coronary spasm can be accomplished safely, but ECG monitoring must be combined with thallium-201 imaging to achieve an acceptable degree of sensitivity.

Adult↗
PubMed1993

Assessment of thallium scintigraphy and echocardiography during dobutamine infusion for the detection of coronary artery disease.

Dobutamine infusion was performed in 16 patients following cardiac catheterization, and non-invasive assessment was performed with thallium SPECT and echocardiography. Dobutamine thallium scintigraphy was abnormal in 93% of patients with significant coronary artery disease. In addition, individual epicardial vessel involvement was identified by a corresponding perfusion defect with 88% sensitivity and 93% specificity. Dobutamine echocardiography revealed segmental wall motion abnormalities in 62% of patients with significant coronary disease. However, in six patients baseline segmental wall motion abnormalities on echocardiography improved during dobutamine infusion. Dobutamine thallium SPECT is a safe and useful test for the detection and localization of coronary artery disease. Dobutamine echocardiography is less useful in screening for coronary disease, but may detect areas of abnormally functioning myocardium having retained viability.

Adult↗
PubMed1980

Predictive value of thallium scintigraphy in coronary artery disease.

To verify the predictive value of thallium exercise scintigraphy, 20 normal individuals and 60 patients with coronary artery disease (CAD) were examined, using a quantitative standard technique and receiver operating characteristic analysis. The sensitivity of thallium scintigraphy for the presence of CAD was 97% for patients with previous infarction and 85% for those without infarction. The sensitivity for the extent of CAD was 93% for vessels perfusing infarcted areas and only 67% for vessels without infarction. In patients without myocardial infarction, sensitivity for the number of diseased vessels decreased with increasing extent of CAD. An underestimation of hemodynamically significant stenoses was proven by a comparison with the results of exercise ventriculography. The predictive value of a normal scintigram at a high prevalence of CAD is as low as the predictive value of an abnormal scintigram at a low prevalence level (screening). Thallium scintigraphy is indicated in patients with a medium prevalence of CAD, e.g., in patients with atypical angina and in asymptomatic patients with pathologic ECG.

Adult↗
PubMed1989

Diagnostic value of atrial pacing and thallium-201 scintigraphy for the assessment of patients with chest pain.

Atrial pacing was performed either alone (n = 23) or in combination with thallium-201 scintigraphy (n = 113) in 136 patients referred for evaluation of chest pain. The presence of coronary artery disease (CAD) was excluded by cardiac catheterization in 12 patients and confirmed in 124. Both pacing-induced ST depression and angina had sensitivities of 48% for CAD; specificities were 75% and 83%, respectively. An abnormal thallium-201 scan (one or more reversible and/or fixed perfusion defects) was seen in 72% of patients with CAD (specificity 83%). Reversible perfusion defects were present in 47% of patients with CAD (specificity 83%), and fixed defects in 36% (specificity 100%). Pacing was associated with either ST depression or an abnormal perfusion scan in 81% of patients (specificity 67%). There were no significant differences in the results of atria pacing or thallium-201 scintigraphy in patients with or without a history of myocardial infarction, or in those with or without previous coronary artery bypass surgery. Pacing-induced ST depression, or both ST depression and a reversible perfusion defect occurred significantly less frequently in patients with peripheral vascular disease than in those without this diagnosis (p less than .05). With only one exception, there were no significant differences in the sensitivities of any indicators of ischemia (ST depression, angina, or perfusion scans), either individually or in combination, as the peak pacing rate or double product achieved increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Thallium-201 perfusion imaging with atrial pacing or dipyridamole stress testing for evaluation of cardiac risk prior to nonvascular surgery.

Preoperative assessment of cardiac risk using thallium-201 scintigraphy and atrial pacing (n = 42) or dipyridamole stress testing (n = 35) was performed in 77 patients (mean age 65 +/- 7 years), who subsequently underwent elective nonvascular surgery. All patients were at low cardiac risk by clinical criteria; none could perform exercise stress testing due to physical limitations. ST depression consistent with ischemia occurred in 11 patients during atrial pacing and in 1 patient during dipyridamole stress testing (p less than 0.01). Nine patients had reversible perfusion defects with atrial pacing, and 10 patients with dipyridamole stress testing; fixed defects were present in 15 and 8 patients, respectively. Only one patient (fixed perfusion defect with atrial pacing, left main disease on coronary angiography) underwent preoperative coronary revascularization. Two patients subsequently had postoperative cardiac events. One patient (reversible perfusion defect with dipyridamole stress testing) experienced sudden death after a nonvascular procedure, while a second patient (normal thallium images with dipyridamole testing) had a nonfatal myocardial infarction. In patients having atrial pacing or dipyridamole stress testing, thallium-201 scans that are normal or show only a fixed perfusion defect confirm a low risk of cardiac complications following nonvascular surgery. The presence of a reversible perfusion defect does not preclude a postoperative course free of cardiac complications in patients at low cardiac risk by clinical criteria.

Aged↗
PubMed1991

Detection of coronary artery disease by vasodilator thallium imaging of the heart with amyl nitrite inhalation: a pilot study.

Thallium imaging of the heart using dipyridamole-induced coronary arteriolar vasodilation has proven to be an effective means of detecting significant coronary stenosis. However, intravenous dipyridamole has not yet been made available for general use. We therefore examined the feasibility of substituting amyl nitrite inhalation as an arteriolar vasodilator prior to thallium imaging. Seventeen patients, all of whom had catheterization-proven coronary stenosis, inhaled amyl nitrite for 2-5 min. Thallium was injected after 45-60 s of inhalation. Completion of inhalation was followed immediately by planar imaging. Of 6 patients who inhaled amyl nitrite for at least 4 min, 5 had moderate or severe image defects on immediate scans which completely resolved on delayed scans. Only 3 of 11 who inhaled amyl nitrite for 2 min or less prior to scanning had similarly positive tests. Overall sensitivity for significant stenosis was 8 of 17 (47%). Inhalation was well tolerated with only one episode of angina and hypotension. We conclude that amyl nitrite inhalation for at least 4 min may offer an effective and readily available alternative to intravenous dipyridamole for vasodilator imaging of the heart.

Administration, Inhalation↗