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Sample records for 201tl myocardial single-photon

  1. Evaluation of acute myocardial infarction by 201Tl single-photon emission computed tomography using scoring system

    In 36 patients with acute myocardial infarction (AMI) 201Tl single photon emission computed tomography (SPECT) examinations were performed in a relatively early phase of AMI. The short and long axis views of the left ventricle (LV) were divided into 6 segments. Images of each segment were assigned scores (segmental scores) based on a visual evaluation of the extent of 201Tl accumulations. SPECT scores were compared with max GOT, max LDT, max CPK and max CK-MB, Killip classification and Forrester hemodynamic subset on admission, and LV ejection fraction (LVEF). Segmental scores were compared with LV wall motion evaluated by left ventriculography. The results are as follows: There were significant correlations between SPECT scores and max GOT, max LDH, max CPK and max CK-MB. SPECT scores in patients with Killip group III were significantly higher than in patients with Killip group I+II. However, no significant differences in max GOT, max LDH, max CPK and max CK-MB were observed between patients with Killip group III and those with Killip group I+II. SPECT scores were significantly higher in patients with Forrester group III+IV than in patients with Forrester group I+II. Segmental scores in segments evaluated as akinesis, dyskinesis and aneurysm by left ventriculography were significantly higher than those evaluated as hypokinesis or normal. Segmental scores in segments evaluated as hypokinesis were significantly high in comparison with normal segments. Significant correlations were observed between LVEF and SPECT scores. However, LVEF correlated poorly with max GOT, max LDH and max CPK, and no significant correlation was observed between LVEF and max CK-MB. SPECT examinations were performed in 11 patients in both the acute and chronic phase of AMI. SPECT scores in the chronic phase did not change in 4 patients, decreased in 5, increased in 2. These results suggest that SPECT scores and segmental scores can be useful indices in the evaluation of AMI. (J.P.N.)

  2. Effects of smoking on myocardial injury in patients with conservatively treated acute myocardial infarction. A study with resting 123I-15-iodophenyl 3-methyl pentadecanoic acid/201Tl myocardial single photon emission computed tomography

    Many reports have demonstrated that smokers who have suffered an acute myocardial infarction (AMI) have a better prognosis than nonsmokers. The present study investigated the effects of current smoking on myocardial injury with resting 123I-15-iodophenyl 3-methyl pentadecanoic acid (BMIPP)/201Tl myocardial single photon emission computed tomography in 103 patients with conservatively treated AMI. The left ventricular myocardium was divided into 9 segments and BMIPP and 201Tl defects were scored using a 5-point grading system (0=normal and 4=no uptake). The sum of the defect scores was defined as the total defect score. There was no significant difference in either the baseline severity of the coronary artery discase or the total defect scores for BMIPP and 201Tl between the current smoker and nonsmoker groups. The difference between the total defect scores for BMIPP and 201Tl tended to be larger in the current smoker group than in the nonsmoker group (2.0±1.9 vs 1.3±1.6, p=0.056). Forty-one (53%) of 77 patients in the current smoker group exhibited a BMIPP/201Tl mismatch, whereas only 8 (31%) of 26 patients in the nonsmoker group did (p=0.047). In conclusion, current smokers had more likelihood of salvageable myocardium in areas at risk, as demonstrated by BMIPP/201Tl mismatch, in AMI than nonsmokers. (author)

  3. Relationship between the mismatch of 123I-BMIPP and 201Tl myocardial single-photon emission computed tomography and autonomic nervous system activity in patients with acute myocardial infarction

    The purpose of this study was to elucidate the relationship between the mismatch of thallium-201 (Tl) and iodine-123-beta-methyl-iodophenyl-pentadecanoic acid (BMIPP) myocardial single-photon emission computed tomography (SPECT) and autonomic nervous system activity in myocardial infarction (MI) patients. The subjects were 40 patients (34 males, 6 females) who underwent examinations by 123I-BMIPP and 201Tl myocardial SPECT imaging and 24-hour Holter monitoring within a 3-day period 3 weeks after the onset of their first MI. R-R intervals were analyzed every hour over a period of 24 hours by fast Fourier transformation (FFT). High frequency (HF) and low frequency (LF) were defined as markers of cardiac vagal activity in the former and the LF/HF ratio as sympathetic activity. Greater or more extensive decreases in the BMIPP image than that in the Tl image were defined as a positive mismatch. Patients were divided into positive and negative mismatch groups of 20 patients each. There were no significant differences between the 2 groups in age, sex, site of infarction, max CK (creatine kinase), max CK-MB, or left ventricular ejection fraction. The incidences of clinical signs suggesting residual myocardial ischemia were significantly greater in the positive than in the negative mismatch group (P123I-BMIPP and 201Tl myocardial SPECT 3 weeks after a first acute myocardial infarction with uncomplicated moderate or severe heart failure and decreased heart rate variability are related to residual myocardial ischemia. A combined assessment of heart rate variability in 24 hour Holter electrocardiogram (ECG) monitoring and perfusion-metabolism mismatch in 123I-BMIPP and 201Tl myocardial SPECT is useful for determining residual myocardial ischemia in the follow-up of those with acute myocardial infarction. (author)

  4. Clinical use of 201Tl myocardial scintigraphy

    Myocardial imaging with 201Tl and scinticamera was studied experimentally using specially designed phantoms and clinically in 23 patients with myocardial infarction or other heart disease. In the phantom experiment, quality of image, accumulative count rate, and detectability of the defect were compared to obtain the best technique for their detection, using four different collimators, i.e., converging, pin-hole, 4000-hole, and 140 keV high-resolution, at two photopeak levels of 201Tl of 75 and 167 keV, and combining a radiation absorber. In patient examination, myocardial images taken at different periods after injection, different detecting conditions of the scinticamera, and various detecting projections were compared. Images of the converging collimator at the 75 keV photopeak revealed considerably higher accumulative counts and relatively higher quality than those of other detecting conditions. It was necessary to take as many images as possible in various projections, in order to detect the location and size of the myocardial ischemic lesion because the lesion was demonstrated as a clear defect only in profile. It became evident that images taken between about 25 and 90 min delineated the myocardium more clearly than those taken in other periods. Normal images taken in 8 patients without ischemic heart disease appeared in the shape of a doughnut of horseshoe, demonstrating mainly the left venticular myocardium. The image was faint in the region of the aortic or mitral valve and thin in the region of the apical wall. A faint image of the right ventricular myocardium was sometimes seen. In 3 patients with valvular heart disease, findings suggested changes in the thickness of myocardium and the distribution of coronary blood flow. In 11 of 12 patients with old myocardial infarction, the location and size of the lesion was detected. (Evans, J.)

  5. Evaluation of infantile ventricular tachycardia by 201Tl myocardial SPECT

    201Tl myocardial SPECT findings in infantile ventricular tachycardia (VT) were examined. The subjects were 4 cases of infantile VT subjected exercise-loading 201Tl scintigraphy in 1990. These cases (3 males and 1 female) were aged 11-14 years, being persistent and non-persistent type VT (2 cases each). Echocardiography revealed no abnormal findings in these 4 cases. Exercise-loading was performed by means of sitting ergometer. ECG revealed sinus arrhythmia except for one case which throughout its course of treatment, had already been presenting ventricular extrasystole from before the excercise-loading. Myocardial SPECT revealed persistent defects (antero-septal wall defects in three cases). The above suggests that 201Tl myocardial SPECT enables us to search for etiology of VT, prognosis and the like. (author)

  6. Effects of smoking on lung uptake of 201Tl during exercise myocardial perfusion imaging

    Objective: To investigate the influence of smoking on lung uptake of 201Tl during myocardial perfusion imaging. Methods: Ninety-two healthy subjects, with normal 201Tl myocardial perfusion imaging findings but no evidence of left ventricular hypertrophy and pulmonary disease, were divided into three groups, smoker, nonsmoker and quitted smoker groups. Exercise/delay 201Tl myocardial perfusion imaging was performed on all subjects included. Lung/heart ratio was defined on the anterior planar image obtained during exercise tomography. Results: Both the lung/heart ratios during exercise in smoker (0.40 ± 0.07, F=10.635, P201Tl lung/heart ratios in smokers are higher than in nonsmokers and this must be kept in mind when 201Tl lung/heart ratios are used clinically, even in quitted smokers

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

    Objective: To evaluate the value of dipyridamole stress 201Tl myocardial SPECT in detecting dysfunction of coronary microcirculation. Methods: Forty-eight patients diagnosed with cardiac syndrome X underwent dipyridamole stress 201Tl myocardial SPECT. Dipyridamole (0.56 mg/kg) was intravenously injected over 4 min followed by 201Tl (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 201Tl 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)201Tl images. After medical treatment, 36 cases of the 42 'reverse redistribution' patients had improvement in both clinical symptoms and treadmill exercise test. Post-treatment 201Tl 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 201Tl imaging showed no improvement in all the 7 defect segments on the first scan. Conclusion: Dipyridamole stress 201Tl myocardial SPECT may be valuable in evaluation of impaired coronary microcirculation associated with cardiac syndrome X. (authors)

  8. 201Tl in myocardial diagnosis: studies on the influence of dipyridamole, dobutamine ergometer exercise and background subtraction on the 201Tl myocadial scintiscam

    Changes in 201Tl myocardial scintiscans upon administration of dipyridamole or dobutamine and upon ergometer exercise relative to scintiscans at rest were investigated as well as the influence of myocardial background subtraction on scintiscan quality and information. A total of 90 201Tl examinations were carried out in 59 patients. 18 patients had no myocardial disease, 30 patients had a coronary disease, 5 patients suffered from cardiomyopathy and 6 from left ventricular hypertrophy. The findings are discussed in detail. (orig.)

  9. Correlation of myocardial uptake of 201Tl with local perfusion in the dog heart

    34 anesthetized and thoracotomized dogs are studied. The local myocardial blood flow is measured with sup(99m)Tc human albumin microsphere. The intramyocardial distribution of 201Tl in relation to local blood flow is studied in basal conditions (24 dogs), after experimental infarction (4 dogs) and postischemic reactive hyperhemia (6 dogs). We conclude that during basal conditions, after infarction and hyperhemia the 201Tl myocardial distribution reflect with damping the variations of blood flow

  10. Diagnostic use of T2-weighted inversion-recovery magnetic resonance imaging in acute coronary syndromes compared with 99mTc-pyrophosphate, 123I-BMIPP and 201TlCl single photon emission computed tomography

    The incidence of missed diagnoses of acute cardiac ischemia in the emergency department could be reduced by a new imaging modality. In the present study, the clinical significance of 99mTc-pyrophosphate (PYP), 123I-β-methyl-p-iodophenyl-pentadecanoic acid (BMIPP), 201TlCl scintigraphy (imaging) and T2-weighted inversion-recovery magnetic resonance imaging (MRI) for the detection of culprit lesion in patients with acute coronary syndromes (ACS) was compared. The study group comprised 18 patients with ACS: 12 patients with acute myocardial infarction (AMI) (11 males; mean age, 63±11 years) and 6 patients with unstable angina (UA) (3 males, mean age, 67±5 years). Of the 12 patients with AMI, 10 underwent 201TlCl and PYP single photon emission computed tomography (SPECT) studies as a dual-energy acquisition (201TlCl/PYP) and 8 underwent 201TlCl SPECT within 1 week of the BMIPP study. All 18 patients underwent BMIPP SPECT and MRI. The MRI pulse sequence was black blood turbo short-inversion-time inversion recovery (STIR) (breath-hold T2-weighted studies). The T2-weighted inversion-recovery MRI showed higher sensitivity and negative predictive value than PYP and 201TlCl, and higher specificity and positive predictive value than BMIPP and 201TlCl. The area under the receiver-operating characteristic curve for PYP, BMIPP, 201TlCl and MRI was 0.787, 0.725, 0.731 and 0.878, respectively. The difference between the areas of MRI and BMIPP was significant (p<0.05). Accurate detection of culprit lesion is improved by using MRI rather than BMIPP, particularly for patients with ACS. (author)

  11. Impact of diabetes mellitus on worsening of the left ventricular ejection fraction in exercise-gated 201Tl myocardial single photon emission computed tomography in patients with coronary artery disease

    It remains uncertain whether factors other than the severity of coronary artery disease (CAD) are associated with the worsening of the left ventricular ejection fraction (LVEF) by exercise. In the present study the impact of coronary risk factors on the worsening of LVEF by exercise was investigated in 391 patients with known or suspected CAD using exercise-gated 201Tl scanning to calculate the LVEF. Significant worsening of the LVEF by exercise was defined as >4.7% (mean plus 1 SD of the value in 116 patients without CAD). Multivariate analysis revealed that diabetes mellitus (DM) was an independent risk factor for the worsening of LVEF by exercise in patients with multivessel (2- or 3-vessel) CAD with an odds ratio (95% confidence interval) of 2.2 (1.1-4.5, p=0.037). In 157 patients with 2- or 3-vessel CAD, 20 (23.5%) of 85 nondiabetic patients and 31 (43.1%, p=0.009 vs nondiabetic patients) of 72 diabetic patients showed significant worsening of LVEF by exercise. In patients with 2- or 3-vessel CAD, there was no significant difference in Gensini score or reversibility of perfusion defects between nondiabetic and diabetic patients. Thus, DM is a risk factor for worsening LVEF by exercise in addition to the severity of CAD. (author)

  12. Dipyridamole 201Tl myocardial SPECT imaging in patients with dilated cardiomyopathy

    Objective: To explore the characteristics of dipyridamole 201Tl myocardial perfusion imaging (MPI) SPECT in patients with dilated cardiomyopathy. Methods: Thirty patients with dilated cardiomyopathy underwent pharmacological stress 201Tl MPI SPECT after intravenous infusion of dipyridamole (0.56 mg/kg) for 4 min. The early and delayed SPECT images were acquired respectively at 10 and 240 min after 201Tl injection. The images were analyzed and reported by two or three experienced nuclear medicine physicians. Results: All patients were found to have abnormal perfusion patterns at delay imaging, however 90.00% (27/30) were also abnormal at early images. Six patients had reverse redistribution. Conclusion: Dipyridamole 201Tl MPI SPECT imaging may be of some value for the assessment of patients with dilated cardiomyopathy. (authors)

  13. Sequential change of cardiomyopathy of Duchenne muscular dystrophy by 201Tl myocardial SPECT

    201Tl myocardial SPECT were performed to evaluate of cardiomyopathy in Duchenne type of progressive muscular dystrophy (DMD). Follow up SPECT images of the same patients were also obtained about 1 year after the first scan. Cases subjected to study were 10 DMD. At the first study the hypoperfusion area of the left ventricular muscle were observed in 6 cases (60%) out of 10. At the second study the hypoperfusion areas became wider and lower in 4 out of 6 cases (66.7%). The new hypoperfusion area which was not demonstrated at the first study was observed at the second study in one case of these cases. These results suggested that the positive rate of cardiomyopathy in DMD by 201Tl myocardial SPECT was high, and 201Tl myocardial SPECT is a useful examination to detect the change of myocardial damage in DMD. (author)

  14. Effects of ischemic-like insult on myocardial 201Tl accumulation

    Despite extensive clinical use of thallium-201 (201Tl) for myocardial imaging, the effect of ischemia on myocardial accumulation and release of 201Tl independent of flow has not been fully defined. Therefore, myocardial accumulation of 201Tl in response to ischemic-like myocardial injury was assessed in vitro using the cultured fetal mouse heart preparation. Cultured fetal mouse hearts (n . 311) were subjected to injury simulating ischemia by deprivation of oxygen and oxidizable substrates for periods ranging from 15 minutes to 10 hours. The extent of irreversible injury was determined by the percentage of lactic dehydrogenase (LDH) lost from the hearts to the culture medium during recovery from injury. Injury was essentially reversible at 1 hour of insult. The fraction of 201Tl content in injured compared with control hearts was not significantly lower after 1 hour of insult. By 3 hours of insult, irreversible injury as assessed by loss of LDH was detectable and the extent of injury increased progressively through 10 hours. During the 3-10-hour period of irreversible injury, 201Tl accumulation within injured hearts compared with controls was related in a monotonically decreasing fashion to the loss of LDH as described by a mathematical kinetic model that fit the observations closely (R2 greater than 0.99). These results indicate that in this organ culture preparation, in which there is effectively an unlimited reservoir of 201Tl and no confounding effects of perfusion, the time-dependent 201Tl accumulation is determined by the extent of irreversible injury

  15. Diagnosis of myocardial ischaemia using exercise ST mapping and afterload 201Tl scintigraphy

    Two non-invasive methods are compared used in the diagnosis of myocardial ischaemia, i.e. precordial exercise mapping of the ST segment and after load 201Tl scintigraphy of the myocardium.High sensitivity of mapping (89.3%) and of 201Tl scan (92.9%) was found compared to the findings on the coronary arteries. The specificity of both methods was lower (57.1%). Both methods give similar results in diagnosis of myocardial ischaemia; for localization the affection site thallium scintigraphy of the myocardium is preferably used. (author). 2 figs., 2 tabs., 23 refs

  16. Correlation of an abnormal rest 201Tl myocardial image: Pathological findings in cardiac transplant recipients

    Rest myocardial 201Tl scintigraphy was undertaken in 15 males mean age 39 years (22-54) who had been accepted for cardiac transplantation. Complete pathological correlation was obtained in 14 after transplantation and in 1 who died before a suitable donor heart became available. The average time from scintigraphy to pathological evaluation was 42 days (9-103). All the 201Tl images were grossly abnormal and on the basis of these studies it was not possible to differentiate ischemic from idiopathic cardiomyopathy. Each of the three views of the 201Tl study was divided into three segments, therefore 135 areas were available for comparison (3 x 3 x 15). Eighty-eight of these were abnormal on scan and 78 of these were abnormal pathologically. The right ventricle was seen on all rest images but the degree of uptake bore no relationship to the measured thickness of the right ventricular wall. Structures such as the atrial wall and the enlarged papillary muscle were visualized in some patients. In two patients there was an improvement of the rest 201Tl image in delayed views and histologically these areas showed a mixture of muscle and fibrous tissue. The sensitivity of 201Tl imaging in this study was 89% and there was close correlation of the images with gross and microscopic pathological findings. (orig.)

  17. Long term retention and excretion of 201Tl in a patient after myocardial perfusion imaging

    201Tl is widely used in nuclear medicine to carry out myocardial perfusion imaging (MPI). However, very limited data is available on long-term distribution in the body, excretion and corresponding dose. In this study we performed a 2 month follow-up of a patient who underwent MPI, by urine analysis and in vivo measurements. The biological half-life of thallium was consequently estimated to be 11.6-27 d, which is in partial agreement with previous studies. We also estimated excretion and retention of 200Tl, 201Tl and 202Tl isotopes using the biokinetic parameters from ICRP publication 53 and compared the forecast result with actual measurements. The latter demonstrated a higher urinary excretion and a higher body retention than what was expected. Our results therefore suggest that the long-term retention and consequently the effective dose coefficient for 201Tl considered in ICRP publications 53 and 80 may be slightly underestimated. (authors)

  18. Long term retention and excretion of 201Tl in a patient after myocardial perfusion imaging.

    Blanchardon, E; Challeton-de Vathaire, C; Boisson, P; Célier, D; Martin, J-C; Cassot, S; Herbelet, G; Franck, D; Jourdain, J R; Biau, A

    2005-01-01

    201Tl is widely used in nuclear medicine to carry out myocardial perfusion imaging (MPI). However, very limited data is available on long-term distribution in the body, excretion and corresponding dose. In this study we performed a 2 month follow-up of a patient who underwent MPI, by urine analysis and in vivo measurements. The biological half-life of thallium was consequently estimated to be 11.6-27 d, which is in partial agreement with previous studies. We also estimated excretion and retention of 200Tl, 201Tl and 202Tl isotopes using the biokinetic parameters from ICRP publication 53 and compared the forecast result with actual measurements. The latter demonstrated a higher urinary excretion and a higher body retention than what was expected. Our results therefore suggest that the long-term retention and consequently the effective dose coefficient for 201Tl considered in ICRP publications 53 and 80 may be slightly underestimated. PMID:15671052

  19. Myocardial scintigraphy with 201Tl and quantitative assessment of myocardial blood flow

    A newly introduced radionuclide for myocardial imaging, 201-Tl, was studied. Twenty-two subjects consisting of 7 normals, 12 with ischemic heart disease and 3 with hypertrophic cardiomyopathy (HCM) were selected. On intravenous administration of 201-Tl(1.5 - 20. mCi), initial transit of the tracer through the heart, as well as subsequent uptake by the myocardium, were recorded by a scintillation camera. The later process showed the distribution of the myocardial blood flow (MBF). A normal myocardial scintigraphy revealed the left-sided myocardial mass predominantly, whereas the right side or the septum predominated in the case of tetralogy of fallot (T/F) or idiopathic hypertrophic subuaortic stenosis (IHSS). An ischemic or infarcted area of the myocardium in ischemic heart disease (IHD) was compatible with electrocardiographic findings, and revealed defects even in an equivocal case on ECG. Since the ratio of radioactivity taken up by the myocardium (U) to the total injected dosis (I) is assumed to be proportional to the fractional MBF of cardiac output (CO), MBF/CO is calculated by ratio of the radioactivity selected from myocardial region on the later recording to that from the entire region on the initial transit of the tracer bolus. The average MBF/CO of normals was 4.4 +- 0.5%, IHD 4.0 +- 0.8% and HCM 5.5 +- 1.2%. On exercise loading, a significant increase of this value was observed in normals, whereas no change was observed in IHD. (auth.)

  20. Detection of coronary artery stenosis in children with Kawasaki disease. Usefulness of pharmacologic stress 201Tl myocardial tomography

    This study determined the feasibility and accuracy of quantitative 201Tl myocardial single-photon emission computed tomography (SPECT) after dipyridamole infusion to detect coronary obstructive lesions in children with Kawasaki disease. 201Tl distribution after dipyridamole infusion was measured in 23 normal children, and with these normal values, quantitative analysis of SPECT was performed in 49 patients. Thirty-four patients had coronary stenosis 90% or greater on angiograms. Side effects resulting from systemic vasodilation were observed in about 70%. Angina pectoris and ischemic ST changes were observed only in patients with coronary stenosis. These symptoms disappeared after aminophylline infusion. Results of visual and quantitative analysis of SPECT were compared. SPECT data were shown on two-dimensional polar maps, and the extent and severity scores were calculated. The sensitivity of SPECT for detection of overall coronary stenosis was 91% (visual analysis) and 88% (quantitative analysis). The specificity of SPECT was 60% visually and 93% quantitatively. The sensitivity of quantitative analysis to detect individual coronary stenosis was similar to that of visual analysis. However, the specificity of visual analysis to detect individual coronary artery stenosis was significantly less than that of quantitative analysis. From these data, we conclude that quantitative analysis of myocardial SPECT after dipyridamole infusion is a safe and accurate diagnostic method for identifying coronary stenosis in children with Kawasaki disease

  1. ATP-loading 201Tl myocardial SPECT for the detection of ischemic heart disease

    To evaluate the usefulness for the detection of ischemic heart disease, ATP myocrdial SPECT was performed in 35 patients (mean; 59±9.4 years) with angina pectoris or old myocardial infarction. Coronary angiography (CAG) was performed in all patients. The ultra-short half-life of ATP required a continuous infusion for its use. ATP was infused intravenously at a rate of 0.16 mg/kg/min for 5 min, with 201Tl injection taking place at 3 min. Myocardial SPECT imaging was begun 5 min and 4 hr later after the end of ATP infusion. ATP caused a significant decrease in arterial blood pressure (p201Tl myocardial SPECT for the detection of coronary artery disease (CAD) was evaluated using CAG as a golden standard. The sensitivity and specificity for CAD detection were 82% and 90%, respectively. ATP myocardial SPECT is a promising new test for the detection of ischemic heart disease. (author)

  2. 201Tl single photon emission tomography in the evaluation of residual and recurrent astrocytoma

    Twenty-five patients with malignant astrocytoma, either postoperatively (15 cases) or with recurrent tumour versus gliosis (10 cases) were included in this study. 201T1 single photon emission computed tomography (SPECT) was performed with the calculation of early and delayed uptake values and retention index. There was a higher sensitivity in detection of tumour viability by 201T1 SPECT of 100% versus 80% using computed tomographic scanning and in the differentiation between recurrent tumour and postradiation gliosis. (author)

  3. [sup 201]Tl single photon emission tomography in the evaluation of residual and recurrent astrocytoma

    Moustafa, H.M.; Ziada, G.A.; El-Ghonimy, E.G. (Cairo Univ., El Mansura (Egypt). Faculty of Medicine); Omar, W.M.; Ezzat, I. (Cairo Univ. (Egypt). Cancer Inst.)

    1994-03-01

    Twenty-five patients with malignant astrocytoma, either postoperatively (15 cases) or with recurrent tumour versus gliosis (10 cases) were included in this study. [sup 201]T1 single photon emission computed tomography (SPECT) was performed with the calculation of early and delayed uptake values and retention index. There was a higher sensitivity in detection of tumour viability by [sup 201]T1 SPECT of 100% versus 80% using computed tomographic scanning and in the differentiation between recurrent tumour and postradiation gliosis. (author).

  4. Parameters for discriminating multiple-vessel coronary artery lesion in exercise 201Tl myocardial SPECT

    This study was performed to select parameters most suitable for discriminating multiple-vessel lesion in exercise 201Tl SPECT. Exercise 201Tl SPECT and coronary contrasting were carried out in 110 patients. At 1 min before the end (appearance of heart pain, severe arrhythmia, hypotension or fatigue) of exercise with a bicycle ergometer, 4 mCi of 201Tl was intravenously injected and myocardial SPECT was done with gamma camera from 32 directions for 20 sec at 5 min and 4 hr after the exercise. Images were analyzed by scaring the uptake of 201Tl for left ventricle. Parameters were Initial score of Tl uptake, Score difference of Tl uptake, Lung/heart, Initial width, Width difference, Diffuse slow washout, Cavity/myocardium, Lung/myocardium and Lung/cavity. Parameters versus Number of diseased vessels were analyzed by chi square method or ANOVA and the parameters for the present purpose were selected by stepwise discriminant analysis. Lung/heart and Initial score were found most suitable. (K.H.)

  5. Is the cardiac function improvement after PTCA predictable by the quantitative indices from exercise stress 201Tl myocardial SPECT, in patients with old myocardial infarction?

    We examined whether the improvement of left ventricular function after percutaneous transluminal coronary angioplasty (PTCA) in patients with one diseased vessel can be predicted by the quantitative indices from exercise stress 201Tl single photon emission computed tomography (SPECT) and radionuclide angiography (RNA) before PTCA. Exercise stress 201Tl myocardial SPECT and RNA were performed before and after PTCA in 28 patients with old myocardial infarction (OMI). The patients were divided into two groups according to the results of coronary angiogram performed at 3 to 6 months after PTCA; patency was confirmed in 22 patients (Group P) and restenosis was observed in the remaining 6 patients (Group S). In Group P, the count ratios defined as 201Tl uptake in the PTCA region divided by the uptake in the normal region were significantly improved at 1 week and 3 to 6 months after PTCA in the initial image. 201Tl washout rates in the normal regions were significantly increased at 1 week after PTCA in Group S, and these rates in the PTCA regions were significantly increased at 1 week after PTCA in Group P. Left ventricular ejection fractions (LVEF) obtained from RNA were significantly improved 1 week and 3 to 6 months after PTCA in Group P. The changes of LVEF between pre-PTCA and 3 to 6 months after PTCA (ΔLVEF) were significantly correlated with the count ratios of both initial and delayed SPECT images in Group P (r=0.652; p<0.01, r=0.645; p<0.01 respectively). From the multiple regression analysis using stepwise methods, the count ratio in delayed image and the LVEF before PTCA were selected as independent predictive variables for ΔLVEF (multiple correlation coefficient=0.776). Thus, the improvement of LVEF after PTCA may be predictable by the count ratio in the delayed SPECT image and LVEF before PTCA when the treated vessel is persistently patent. (author)

  6. Thallium chloride 201Tl combined with single photon emission computed tomography (SPECT) in the evaluation of vestibular schwannoma growth

    Charabi, Samih Ahmed; Lassen, N A; Thomsen, J;

    1997-01-01

    Thallium chloride 201Tl combined with SPECT was performed in a series of 29 patients with neuroradiological evidence of vestibular schwannoma (VS). The relative tumor uptake (U) and relative tumor concentration (C) of the radiotracer 201Tl was determined, and the cerebellum served as a reference...

  7. Contamination of clothing and other items by sweat during exercise 201Tl myocardial perfusion scintigraphy

    We measured the radioactivity on patient's upper and lower garments, towels, broad sashes for the bust, and electrodes contaminated by sweat due to exercise 201Tl myocardial perfusion scintigraphy. In measuring activity, a scintillation survey meter adjusted to the energy of 201Tl was used. In measuring the radioactivity of clothing, more than 4 Bq/cm2 was considered to be a significant level of contamination. We detected contamination in 30% of upper garments and towels, 19% of broad sashes, 8% of lower garments and 4% of electrodes. Among these materials, several items of clothing and other items showed contamination exceeding 40 Bq/cm2. Towels were remarkably contaminated, with one towel showing a maximum contamination level of 420 Bq/cm2. Examinations done by exercise 201Tl myocardial perfusion scintigraphy often result in the contamination of clothing and other items through sweating. This contamination is especially common in summer, particularly in upper garments and towels. The contamination ratio for towels was over 50%. The contamination ratio increased as the level of exercise became more difficult. When the exercise load was more than 100 W, the contamination ratio was 50%. In cases of extreme contamination, images of contaminated upper garments could be obtained by the scintigraphy camera. The areas of high activity on the images seemed to correspond to areas of the body where sweating was profuse. Based on these results, we should pay close attention to the handling of clothing and other items used in exercise testing by 201Tl myocardial perfusion scintigraphy and the points used in measuring contaminated clothing and other items after testing. (author)

  8. Limited performance of quantitative assessment of myocardial function by thallium-201 gated myocardial single-photon emission tomography

    We investigated the reproducibility between thallium-201 and technetium-99m methoxyisobutylisonitrile (MIBI) gated single-photon emission tomography (SPET) for the assessment of indices of myocardial function such as end-diastolic and end-systolic volume (EDV, ESV), ejection fraction (EF) and wall motion. Rest 201Tl (111 MBq) gated SPET was sequentially performed twice in 20 patients. Rest 201Tl gated SPET and rest 99mTc-MIBI (370 MBq) gated SPET were performed 24 h apart in 40 patients. Wall motion was graded using the surface display of the Cedars quantitative gated SPET (QGS) software. EDV, ESV and EF were also measured using the QGS software. The reproducibility of functional assessment on rest 201Tl gated SPET was compared with that on 99mTc-MIBI gated SPET, and also with that between 201Tl gated SPET and 99mTc-MIBI gated SPET performed on the next day. The two standard deviation (2 SD) values for EDV, ESV and EF on the Bland-Altman plot were 29 ml, 19 ml and 12%, respectively, on repeated 201Tl gated SPET, compared with 14 ml, 11 ml and 5.3% on repeated 99mTc-MIBI gated SPET. The correlations were good (r=0.96, 0.97 and 0.87) between the two measurements of EDV, ESV and EF on repeated rest studies with 201Tl and 99mTc-MIBI gated SPET. However, Bland-Altman analysis revealed that the 2 SD values between the two measurements were 31 ml, 23 ml and 12%. We were able to score the wall motion in all cases using the 3D surface display of the QGS on 201Tl gated SPET. The kappa value of the wall motion grade on the repeated 201Tl study was 0.35, while that of the wall motion grade on the repeated 99mTc-MIBI study was 0.76. The kappa value was 0.49 for grading of wall motion on repeated rest studies with 201Tl and 99mTc-MIBI. In conclusion, QGS helped determine EDV, ESV, EF and wall motion on 201Tl gated SPET. Because the EDV, ESV and EF were less reproducible on repeated 201Tl gated SPET or on 201Tl gated SPET and 99mTc-MIBI gated SPET on the next day than on repeated

  9. Evaluation of viability of infarcted myocardium by low dose dobutamine stress echocardiography. Comparison with exercise stress 201Tl myocardial scintigraphy

    Exercise stress 201Tl myocardial single-photon emission computed tomography (SPECT) is recognized to be a excellent method for identifying viability after myocardial infarction, but it is expensive and needs a longer time for data acquisition than echocardiography. We therefore performed this study to evaluate the effectiveness of low dose (5-10 μg/kg/min) dobutamine stress echocardiography (DSE) in 30 patients (61±8 years old: 24 men and 6 women) within 4 weeks after myocardial infarction in identifying viable myocardium, compared to results obtained by SPECT. Defining an akinetic or dyskinetic segment obtained by rest echocardiography as a definite infarct area, altogether 96 segments out of 716 segments were shown to be infarct areas. Of these, 75 (78%) segments were identified as viable by DSE, and 77 (80%) by SPECT. Only 2 segments were shown to be discrepant on DSE and SPECT. Subsequently, the sensitivity, specificity and accuracy rates for DSE were 96%, 100% and 96%, respectively. In conclusion, DSE is as effective and useful as SPECT in the evaluation of viability after myocardial infarction. (author)

  10. 201Tl myocardial perfusion in the management of transplanted heart

    A semi quantitative method with thallium has been applied in the management of cardiac transplants. In all, 142 scans were performed in 20 patients and were arranged in 3 groups that represent respectively all controls performed to the transplants (G1), and a selection of the scans obtained during the 1st rejection episode in each patient (G2) and the 2nd if present (G3). A heart/lung index was calculated through early and late images (IA, IB,) obtained 5 min and 4 h post injection of thallium. A decrease in IA was detected during acute rejection in all groups. This fall was statistically significant from the mild to moderate rejection degree in G1 (P3 (PB was not modified with rejection. Comparing the biopsies with and without edema, in the absence of rejection, it has been proved that the intra myocardial edema can produce a decrease in IA (PA is a simple and sensitive index to evaluate the graft, although intra myocardial edema can reduce its specificity. (orig.)

  11. Myocardial reversibility detection. Rest NTG 99mTc-MIBI versus 201Tl reinjection. Preliminary results

    This study test whether sublingual administration of nitroglycerin (NTG) could improve the capability of 99mTc-MIBI to detect reversibility in exercise-induced perfusion defects and to compare it with the 201Tl stress-redistribution-reinjection protocol. Twenty-one patients with previous myocardial infarction were submitted to exercise, rest and NTG rest 99mTc-MIBI imaging (3-day protocol). The patients also underwent exercise, redistribution and reinjection 201Tl myocardial scintigraphy. A total of 273 myocardial segments were analyzed: 76 (28%) had irreversible defects on stress-rest 99mTc-MIBI, 60 (79%) appeared as fixed defects and 16 (21%) were reversible on NTG rest 99mTc-MIBI. Of the 78 myocardial segments with irreversible defects on standard stress-redistribution thallium cardiac imaging, 63 (81%) did not change and 15 (19%) demonstrated enhanced uptake of thallium after reinjection. Data show that rest NTG 99mTc-MIBI study improves the detection of reversible myocardium versus standard exercise/rest 99mTc-MIBI and achieve similar results than 201TI reinjection protocol. (author)

  12. Evaluation of coronary hemodynamics and exercise sup 201 Tl-myocardial scintigraphy in patients with vasospastic angina

    Matsumura, Kentaro; Nakase, Emiko; Haiyama, Tohru; Hasegawa, Akira; Saito, Takayuki (Kyoto Minami Hospital (Japan))

    1992-05-01

    To clarify the coronary hemodynamics and myocardial perfusion in patients with vasospastic angina, we performed exercise {sup 201}Tl-myocardial scintigraphy (planar and SPECT) in 72 patients and left coronary digital subtraction angiography (DSA) in 37 patients without significant organic coronary artery stenosis. Coronary artery spasm was documented by coronary angiography in all patients. Fifty-four patients (75%) developed exercise-induced {sup 201}Tl-myocardial perfusion defect on SPECT. {sup 201}Tl pulmonary uptake (L/H) was significantly increased in patients with vasospastic angina. Especially, L/H was higher in patients with multiple small perfusion defect on {sup 201}Tl-SPECT, so that exercise-induced left ventricular dysfunction existed in patients with vasospastic angina and especially in cases of multiple small perfusion defect on {sup 201}Tl-SPECT. The left coronary circulation time (CCT) was prolonged in patients with vasospastic angina. The mechanism of prolonged CCT is still unknown, but we suspected that prolonged CCT was induced by increased peripheral coronary vascular resistance in patients with vasospastic angina. It was concluded that the peripheral coronary circulation was disturbed in patients with vasospastic angina, but its abnormal coronary circulation had no relation to location of spasm-induced vessels. We concluded that impaired coronary microcirculation was taken a part of pathophysiology in vasospastic angina. (author).

  13. Emission computed tomography using rotating gamma cameras for stress 201Tl myocardial imaging

    The purpose of this study is to evaluate the efficacy of emission computed tomography (ECT) for stress 201Tl myocardial imaging to localize coronary artery disease (CAD) in comparison with planar (PL) images. In a series of 14 normal subjects and 53 patients with CAD proved coronary arteriography, ECT and PL imaging were performed successively. ECT data were collected for 90 projections in a 64 x 64 matrix form with a total aquisition time of 6 munutes over 1800 of opposed dual cameras ratation and tomographic sections oriented perpendicular and parallel to the long axis of left ventricle were reconstructed. PL images were obtained for left lateral, left anterior oblique (300 and 450) and anterior projections. Both ECT and PL myocardial images were divided into 8 segments and segmental analysis was performed by visual interpretation. The ECT images remarkably increased sensitivity over the PL images in left anterior descending (LAD) artery (from 56% to 76%), right coronary artery (RCA) (from 50% to 96%), and circumflex artery (CX) (from 56% to 69%) lesions. The specificity for ECT images, as compared with PL images, was higher in LAD (88% against 85%) but slightly lower in RCA (70% ag ainst 72%) and CX (84% against 88%). Overall accuracy, therefore, was improved in LAD (from 67% to 81%) and RCA (from 64% to 79%) but equal in CX (81%). We conclude that stress 201Tl ECT imaging result in a remarkable improvement in the localization of CAD, especially in patients with RCA lesions and multi-vessel disease. (author)

  14. Microvascular obstruction on delayed enhancement cardiac magnetic resonance imaging after acute myocardial infarction, compared with myocardial {sup 201}Tl and {sup 123}I-BMIPP dual SPECT findings

    Mori, Hiroaki [Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya (Japan); Department of Cardiology, Kainan Hospital, Yatomi (Japan); Isobe, Satoshi, E-mail: sisobe@med.nagoya-u.ac.jp [Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya (Japan); Sakai, Shinichi [Department of Cardiology, Kainan Hospital, Yatomi (Japan); Yamada, Takashi [Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya (Japan); Watanabe, Naoki; Miura, Manabu [Department of Cardiology, Kainan Hospital, Yatomi (Japan); Uchida, Yasuhiro; Kanashiro, Masaaki; Ichimiya, Satoshi [Department of Cardiology, Yokkaichi Municipal Hospital, Yokkaichi (Japan); Okumura, Takahiro; Murohara, Toyoaki [Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya (Japan)

    2015-08-15

    Highlights: • The percentage infarct size (%IS) was significantly greater in the microvascular obstruction (MO) group than in the non-MO group. • The percentage mismatch score (%MMS) on dual scintigraphy significantly correlated with the %IS and the percentage MO. • The %MMS was significantly greater in the non-MO group than in the MO group, and was an independent predictor for MO. - Abstract: Background: The hypo-enhanced regions within the hyper-enhanced infarct areas detected by cardiac magnetic resonance (CMR) imaging reflect microvascular obstruction (MO) after acute myocardial infarction (AMI). The combined myocardial thallium-201 ({sup 201}Tl)/iodine-123-15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid ({sup 123}I-BMIPP) dual single-photon emission computed tomography (SPECT) is a useful tool for detecting myocardial reversibility after AMI. We evaluated whether MO could be an early predictor of irreversible myocardial damage in comparison with {sup 201}Tl and {sup 123}I-BMIPP dual SPECT findings in AMI patients. Methods: Sixty-two patients with initial AMI who successfully underwent coronary revascularization were enrolled. MO was defined by CMR imaging. Patients were divided into 2 groups as follows: MO group (n = 32) and non-MO group (n = 30). Scintigraphic defect scores were calculated using a 17-segment model with a 5-point scoring system. The mismatch score (MMS) was calculated as follows: the total sum of (Σ) {sup 123}I-BMIPP defect score minus Σ{sup 201}Tl defect score. The percentage mismatch score (%MMS) was calculated as follows: MMS/(Σ{sup 123}I-BMIPP score) × 100 (%). Results: The percentage infarct size (%IS) was significantly greater in the MO group than in the non-MO group (32.2 ± 13.8% vs. 18.3 ± 12.1%, p < 0.001). The %MMS significantly correlated with the %IS and the percentage MO (r = −0.26, p = 0.03; r = −0.45, p < 0.001, respectively). The %MMS was significantly greater in the non-MO group than in the MO group (45.4

  15. Impaired Coronary Flow Reserve Is the Most Important Marker of Viable Myocardium in the Myocardial Segment-Based Analysis of Dual-Isotope Gated Myocardial Perfusion Single-Photon Emission Computed Tomography

    Lee, Won Woo; So, Young; Kim, Ki-Bong; Lee, Dong Soo

    2014-01-01

    Objective The aim of this study was to investigate the most robust predictor of myocardial viability among stress/rest reversibility (coronary flow reserve [CFR] impairment), 201Tl perfusion status at rest, 201Tl 24 hours redistribution and systolic wall thickening of 99mTc-methoxyisobutylisonitrile using a dual isotope gated myocardial perfusion single-photon emission computed tomography (SPECT) in patients with coronary artery disease (CAD) who were re-vascularized with a coronary artery by...

  16. 201Tl myocardial scintigraphy correlation with TMT and coronary angiography - a preliminary report

    Full text: This study analyses 60 patients of suspected ischemic heart disease who underwent myocardial perfusion studies with 201Tl SPECT from June 1998 - September 1998. Thirty six patients were tested positive on TMT, thallium scintigraphy was positive in 21 (58%) patients and negative in 15 (41%) cases. Coronary angiography results were available in 35 patients, of which there were 5 cases with LBBB where TMT was not done due to high unpredictability. The 5 cases were tested negative, both angiographically and stress thallium showing 100% correlation. Out of remaining 30 patients, angiography was positive in 22 patients. Stress thallium was positive in 19 patients (87%). Of the 8 cases which showed normal coronary angiography, stress thallium was positive in 3 cases (13%) and negative in 5 patients (87%). Statistical analysis of this small group showed a sensitivity of 86%, specificity of 63%, false negative rate 14% and false positive rate of 37%. Overall accuracy is 80%

  17. Crosstalk analysis of simultaneously acquired dual-isotope 201tl myocardial perfusion SPECT and 99Tcm-RBC equilibrium ventricle imaging

    Objective: To analysis the crosstalk between the 20'1Tl and 99Tcm while the myocardial SPECT imaging with 201Tl and the equilibrium ventricle imaging with 99Tcm-RBC are simultaneously acquired, and to search after a method to reduce the down scatter of 99Tcm in the 201Tl window. Methods: Myocardial perfusion images were acquired using a cardiac phantom, which can present various levels of ischemia. The pulse height analysis was performed before the SPECT acquisition. The down scatter ratio of different 201Tl doses was calculated on each project with variable acquisition energy window. After the raw data were reconstructed with Butterworth filter, the defect-to-myocardium count ratios from different 201Tl acquisition window and variable defect levels were compared. Results: During the dual-isotope acquisition with 201Tl and 99Tcm the main crosstalk was the down scatter of 99Tcm in 201Tl window, which was considerably reduced while using higher dosage of 201Tl. The down scatter was also inhibited by applying more specific energy window of 201Tl. The defect-to-myocardium ratio analysis showed that only the data acquired under 15% energy window were affected on the contrast of the defects in short axis slice. The window of 201Tl and the extent of the ischemia influenced the defect-to-myocardium ratios of mimic ischemia segments differently. The completely defect group appeared insensible to the change of acquisition window. Between the defect-to-myocardium ratio of 33% filled group and the 66% filled group considerable difference was demonstrated while the acquisition window of 20% was used. Conclusions: The down scatter of 99Tcm is the major factor which influences the simultaneous dual-isotope acquisition. The stain can be reduced either using more specific 201Tl energy acquisition window or applying higher dosage of 201Tl. But due to the long half-life of 201Tl, the authors can not increase the dosage discretionarily. As the more specific window of 201Tl can avoid

  18. Quantitative evaluation of right ventricular overload in cor pulmonale using 201Tl myocardial SPECT

    To determine quantitatively the discriminant and characteristics of cor pulmonale, 201Tl myocardial perfusion SPECT was performed in 16 patients with chronic obstructive pulmonary disease (COPD) and 7 with restrictive pulmonary disease (RPD). One section of the short-axis SPECT image in which the right ventricle was most clearly visualized was selected. Tl-score was defined as the ratio of the sum of counts in the region of interest (ROI) at the anterior, mid, and posterior regions of the right ventricular free wall to the sum of counts in ROI at the posterior, lateral, and anterior walls of the left ventricle, and the anterior and posterior regions of the interventricular septum. In the group of COPD patients, Tl-score was positively correlated with mean pulmonary arterial pressure (mPAP), total pulmonary vascular resistance (TPR), and arterial carbon dioxide tension (PaCO2), while it was inversely correlated with arterial oxygen tension (PaO2). However, there was no significant correlation between Tl-score and mPAP, TPR, PaCO2, and PaO2 in the group of RPD patients. In assessing pulmonary hypertension as defined by mPAP over 20 mmHg, a Tl-score greater than 0.25 was useful with a sensitivity of 69% and a specificity of 90%. The occurrence of cor pulmonale is a major factor in determining the prognosis of COPD patients. It was concluded that 201Tl myocardial SPECT is useful for evaluating right ventricular overload quantitatively, as well as for assessing core pulmonale, especially in COPD patients, since the ratio of Tl counts in the right and left ventricles was significantly correlated with right cardiopulmonary hemodynamic parameters. (N.K.)

  19. Myocardial scintigraphy using 99m-Tc-methoxyisobutylisonitrile (Tc-MIBI): A full substitution of 201-Tl?

    The results of selective coronary angiography, myocardial 201-Tl scintigraphy (stress and redistribution) and after 99m-Tc-methoxyisobutylisonitrile stress and rest injections (Tc-MIBI, Cardiolite, DuPont de Nemours, USA) were compared in 19 patients with manifest ischemic heart disease in identical three projections and after same ergometric load. 16 patients had significant stenoses of 1-3 main coronary arteries inclusive of left coronary artery main stem, insignificant stenoses (<50%) were present in the remaining 3 patients. Scintigraphic localizations of accumulation defects in both Tc-MIBI and 201-Tl stress scintigraphy were in agreement in 70.6% of evaluated left ventricular wall segments. A positive 201-Tl redistribution and rest-stress Tc-MIBI scintigraphic difference agreed in 52.6% of images of all three projections with verified accumulation defects. The sensitivity of ischemic area detection in reference to coronary angiography was nearly identical in 201-Tl (75%) and Tc-MIBI scintigraphy (81.2%). Better physical properties of 99m-Tc from the point of view of a gamma camera detection, a possibility to get markedly higher counting rate and sufficient accumulation of the radiopharmaceutical in the perfused myocardium enable to reach scintigraphic pictures with a high contrast after labelled Tc-MIBI injection, even in case of sequential impulse summation during heart cycle (gating). (author) 1 tab., 1 fig., 14 refs

  20. Effect of wall thickness of left ventricle on {sup 201}Tl myocardial SPECT images. Myocardial phantom study

    Koto, Masanobu; Kawase, Osami [Kobe Univ. (Japan). Hospital; Namura, Hiroyuki; Yamasaki, Katsuhito; Kono, Michio

    1996-07-01

    {sup 201}Tl myocardial SPECT is known for better sensitivity, specificity, and accuracy than planar images in detecting coronary artery disease and diagnosing myocardial viability. SPECT images arc also superior to planar images in diagnostic sensitivity and anatomical orientation. However, as limitation of the spatial resolution of the machine, we often encounter poor SPECT plower image quality in patients with decreased wall thickness. To test the accuracy of SPECT images in patients with marked thinning of the left ventricular wall, as occurs in dilated cardiomyopathy, we performed a experimental study using myocardial phantom with 7 mm wall thickness. Tomographic image of the phantom images were rather heterogeneous, though no artificial defect was located Dilated cardiomyopathy is thought to be characterized by patchy defects in the left ventricle. Careful attention should be given to elucidating myocardial perfusion in patients with a thin left ventricle wall, as there are technical limitations in addition to clinical features. (author)

  1. Coronary artery disease detected noninvasively by dipyridamole-loading 201Tl myocardial scintigraphy in elderly patients

    To evaluate the usefulness in diagnosing coronary artery disease (CAD), dipyridamole-loading 201Tl myocardial scintigraphy was performed for 52 elderly patients (65 - 92 years, mean: 72 years), and the results were compared with data from the treadmill exercise tests. 1. Thirty-five patients could not tolerate adequate exercise tests. Seven of them had reversible defects; six, fixed (irreversible) ones. Dipyridamole scintigraphy is therefore applicable in detecting CAD among patients with suspected CAD who are unable to perform adequate exercise tests. 2. Four of 16 patients with positive exercise tests had no reversible defects; the exercise results in three were regarded as false positives. 3. Seventeen patients experienced chest pain; 12 had ST depression during dipyridamole loading. There were no serious complications, but seven patients required aminophylline. 4. We demonstrated previously that the sensitivity and specificity of dipyridamole scintigraphy in detecting CAD were 90 % and 92 %, respectively, in patients with chest pain undergoing coronary angiography. These results were superior to those of conventional exercise myocardial scintigraphy. Therefore, dipyridamole scintigraphy is regarded as a safe and useful method for detecting CAD, particulary in elderly patients who have ST and T wave abnormalities but cannot tolerate exercise test adequately. (author)

  2. 201Tl myocardial SPECT and β-endorphin levels in patients with suspected silent ischemia

    Today silent myocardial ischemia (SMI) is a well-recognized phenomenon. Treadmill exercise according to the Bruce protocol, 201Tl myocardial SPECT and coronary angiography were performed in a total of 106 patients with suspected SMI. In group I (high probability of ischemia; n=46), reversible defects detected by SPECT correlated well with significant stenoses and irreversible defects with subtotal stenoses or complete occlusions. SPECT sensitivity in the detection of ischemia was 91%, its specificity 96%. In group II (low probability of ischemia; n=60), SPECT sensitivity was as high as in group I (94%) but due to a high number of false-positive results (e.g. cardiomyopathy) specificity was only 75%. However, SPECT was superior to exercise ECG (sensitivity 70%; specificity 56%) in the detection of SMI. In addition, β-endorphin levels were determined in 180 healthy subjects, 37 patients with symptomatic CAD and in 34 patients with SMI before and during maximum exercise. Exercise values in patients with SMI were significantly higher than in healthy subjects or in patients with symptomatic CAD. (orig./MG)

  3. Improvement of myocardial perfusion detected by 201Tl scintigraphy on cardiac rehabilitation for patients with coronary artery disease

    The effect of cardiac rehabilitation (mean 70±48 months) on myocardial perfusion was assessed using thallium-201 (201Tl) exercise study in 63 patients with coronary artery disease (CAD). Subjects were those in a rehabilitation group (Rh=42) participating in supervised sports training two to three times per week and the control group (Ct=21) not taking active daily exercise. The interval between two 201Tl SPECT studies was 19±16 months. After physical training, total duration of the exercise test increased from 443±112 to 536±121 seconds (+19%) in the Rh group, and from 484±129 to 432±115 seconds in the Ct group (-10.7%) (p2 to 269.8±58 x 102 in the Rh group and decreased from 218.7±40 x 102 to 216.6±76 x 102 (p201Tl myocardial perfusion defect on exercise improved more in 54.8% (stress 59.5%, rest 35.7%) in the Rh group than in the Ct group (9.5%, p201Tl perfusion defect decreased from 68 (23.1%) to 49 regions (16.7%) of 294 total myocardial regions in the Rh group on exercise. However. it increased from 39 (26.5%) to 44 (29.9%) regions of 147 regions in the Ct group (p<0.01). Thus, cardiac rehabilitation increases exercise tolerance with improvement of myocardial perfusion. suggesting that cardiac rehabilitation is an advisable and effective treatment for patients with ischemic heart disease. (author)

  4. Cost-effectiveness of exercise 201Tl myocardial SPECT in patients with chest pain assessed by decision-tree analysis

    To evaluate the potential cost-effectiveness of exercise 201Tl myocardial SPECT in outpatients with angina-like chest pain, we developed a decision-tree model which comprises three 1000-patients groups, i.e., a coronary arteriography (CAG) group, a follow-up group, and a SPECT group, and total cost and cardiac events, including cardiac deaths, were calculated. Variables used for the decision-tree analysis were obtained from references and the data available at out hospital. The sensitivity and specificity of 201Tl SPECT for diagnosing angina pectoris, and its prevalence were assumed to be 95%, 85%, and 33%, respectively. The mean costs were 84.9 x 104 yen/patient in the CAG group, 30.2 x 104 yen/patient in the follow-up group, and 71.0 x 104 yen/patient in the SPECT group. The numbers of cardiac events and cardiac deaths were 56 and 15, respectively in the CAG group, 264 and 81 in the follow-up group, and 65 and 17 in the SPECT group. SPECT increases cardiac events and cardiac deaths by 0.9% and 0.2%, but it reduces the number of CAG studies by 50.3%, and saves 13.8 x 104 yen/patient, as compared to the CAG group. In conclusion, the exercise 201Tl myocardial SPECT strategy for patients with chest pain has the potential to reduce health care costs in Japan. (author)

  5. Evaluation of the graft flow reserve after coronary artery bypass grafting by stress 201Tl myocardial SPECT. Comparison between arterial grafts and venous grafts

    We performed stress 201Tl myocardial SPECT to evaluate ischemia and perfusion reserve after coronary artery bypass grafting (CABG). A total of 103 patients was performed stress 201Tl myocardial SPECT one month after CABG. Each patient's myocardium was divided into 9 segments and visually evaluated using five grade scoring system (0=defect, 1=severe decrease, 2=moderate decrease, 3=mild decrease, 4=normal uptake). Eleven of 133 (8.27%) segments covered by patent venous grafts showed reversible 201Tl defect, however, 36 of 117 (30.8%) segments which covered by patent arterial grafts showed reversible 201Tl defect. This finding was observed more significantly in arterial grafts than in venous grafts (p<0.001). These finding suggests that arterial grafts have lower flow capacity than venous grafts at peak exercise. (author)

  6. Evaluation of the graft flow reserve after coronary artery bypass grafting by stress {sup 201}Tl myocardial SPECT. Comparison between arterial grafts and venous grafts

    Ichikawa, Akihiro; Taki, Junichi; Nakajima, Kenichi; Kawasuji, Michio; Tonami, Norihisa [Kanazawa Univ. (Japan). School of Medicine

    1997-01-01

    We performed stress {sup 201}Tl myocardial SPECT to evaluate ischemia and perfusion reserve after coronary artery bypass grafting (CABG). A total of 103 patients was performed stress {sup 201}Tl myocardial SPECT one month after CABG. Each patient`s myocardium was divided into 9 segments and visually evaluated using five grade scoring system (0=defect, 1=severe decrease, 2=moderate decrease, 3=mild decrease, 4=normal uptake). Eleven of 133 (8.27%) segments covered by patent venous grafts showed reversible {sup 201}Tl defect, however, 36 of 117 (30.8%) segments which covered by patent arterial grafts showed reversible {sup 201}Tl defect. This finding was observed more significantly in arterial grafts than in venous grafts (p<0.001). These finding suggests that arterial grafts have lower flow capacity than venous grafts at peak exercise. (author)

  7. Development of normal limits for left ventricular ejection fraction measured from gated myocardial perfusion SPECT with 99Tcm-MIBI and 201Tl

    Objective: To develop normal limits for left ventricular ejection fraction (LVEF) measured from gated myocardial perfusion SPECT with 99Tcm-methoxyisobutylisonitrile (MIBI) and 201Tl. Methods: Gated myocardial perfusion SPECT with 99Tcm-MIBI and 20'1Tl was performed on 277 patients with a low Bayesian likelihood (99Tcm-MIBI [normotensive subgroup: n=85; hypertension without left ventricular hypertrophy (LVH) subgroup: n=25] and 201Tl(n=167, normotensive subgroup: n=128; hypertension without LVH subgroup: n=39). The resting LVEF was calculated using an automatic gated myocardial perfusion SPECT processing software. Results: The hypertension without LVH subgroup had significantly higher resting LVEF values compared with normotensive subgroup (P99Tcm-MIBI group and 20'1Tl group. Sex differences were marked: men had significantly lower mean resting LVEF values than women (P0.05). The distributions for resting LVEF values in 99Tcm-MIBI group and 201Tl group were Gaussian (P>0.05). The normal limits were LVEF≥45% in 99Tcm-MIBI (≥45% in men, ≥48% in women) and ≥43% in 201Tl (≥42% in men, ≥47% in women) Conclusion: These normal limits can be evaluated prospectively for their potential clinical value

  8. Clinical assessment of myocardial viability by stress-reinjection 201Tl/rest 99mTc-MIBI dual-isotope imaging strategy

    Objectives: To assess area and severity of myocardial ischemia and myocardial viability by dobutamine stress-reinjection 201Tl/ rest 99mTc-MIBI dual-isotope myocardial perfusion tomography. Methods: The study included 35 patients who underwent tress-reinjection 201Tl/ rest 99mTc-MIBI dual-isotope SPECT and coronary angiography (CAG). Dobutamine stress was carried out 20 min after 99mTc-MIBI was injected intravenously at rest, then 201Tl was administrated intravenously, and dual-isotope SPECT was performed instantly. Because both of stress 201Tl and rest 99mTc-MIBI imaging showed area of defect radioactivity, 1mCi 201Tl was reinjected at rest, dual-isotope SPECT was performed again 4 hours later. Results: (1) of 86 segments showing defected activity, 54 segments were fill with radioactivity and the other 32 segments were not improved after 201Tl was reinjected. (2) All of 35 patients, 9 patients were normal and 26 patients were abnormal by coronary angiography (one cronory artery stenosis in 2 patients, 2 coronary arteries stenosis in 7 patients, 3 coronary arteries stenosis in 17 patients.). There were 17 patients with 50-75% coronary stenosis, 3 patients with 75-85% coronary stenosis and 15 patients with more than 85% coronary stenosis. The stenosis coronary arteries detected by coronary angiography were consistent with those detected by tress-reinjection 201Tl/ rest 99mTc-MIBI dual-isotope SPECT. (3) Assessed by stress-reinjection 201Tl/ rest 99mTc-MIBI dual-isotope SPECT, all ischemic cardiac muscles in 26 patients with CAD were viable. Of 26 CAD patients, 2 patients underwent PTCA, 2 patients underwent PCI, 6 patients underwent CABG in two or more vessels, 1 patient was treated with thrombolysis, the other 15 patients received medical treatment. (4) 14 segments with defect activity were detected by myocardial imaging in 9 normal patients by CAG. Of them, 5 segments were in lateral wall, 3 segments in anterior wall, 7 segments in septal wall near basement. 11

  9. Evaluation of myocardial disorders in patients with dilated cardiomyopathy and left ventricular eccentric hypertrophy; By sup 201 Tl myocardial SPECT

    Yamazaki, Junichi; Ohsawa, Hidefumi; Uchi, Takashi (Toho Univ., Tokyo (Japan). School of Medicine) (and others)

    1992-03-01

    {sup 201}Tl myocardial SPECT was performed in cases of dilated cardiomyopathy and valvular heart disease with left ventricular eccentric hypertrophy, and the two groups were compared from the standpoint of the mechanism of onset of myocardial disorders. Significant coefficients of correlation were seen between the Tl score and LVDd (r=0.792, r=0.785) and Tl score and LVEF (r=-0.634, r=-0.555) in both dilated cardiomyopathy and valvular heart disease. In cases of valvular heart disease, significant correlation coefficients (r=-0.756, r=-0.720) between LVDd and r-WR (relative-washout rate), and Tl score and r-WR were observed, but no such correlation was seen in dilated cardiomyopathy. In valvular heart disease, a decrease in myocardial perfusion associated with enlargement of the left ventricle appeared, while in dilated cardiomyopathy, there was a marked decrease in LVEF in proportion to the thallium defect. Therefore, it was assumed that left ventricular wall disorders occur due to myocardial metabolic disorders and coronary microcirculation disorders. (author).

  10. Clinical implications of increased lung uptake of 201Tl during exercise scintigraphy 2 weeks after myocardial infarction

    To determine the prevalence and clinical significance of increased lung 201Tl uptake during submaximal exercise myocardial scintigraphy performed 2 weeks after acute myocardial infarction, 61 patients underwent submaximal exercise testing (target heart rate, 120 beats/min), multigated blood pool imaging at rest and coronary angiography before hospital discharge. Thallium lung uptake on the initial anterior projection image was graded qualitatively by comparing the intensity of 201Tl activity in the lungs with that in the mediastinum. In 39 patients (64 percent), it was normal (equal to mediastinal activity) and in 22 (36 percent), it was increased (greater than mediastinal activity). Compared with patients with normal lung uptake, those with increased uptake had a greater prevalence of prior infarction (13 versus 36 percent, probability [p] less than 0.05), less global cardiac reserve as assessed by the four level New York Heart Association classification (p less than 0.05), more advanced Killip class in the coronary care unit (p less than 0.05), a higher Norris coronary prognostic index (2.6 +/- 1.9 versus 4.6 +/- 2.3 [mean +/- standard deviation], p less than 0.01), failure to achieve the target heart rate because of dyspnea, fatigue or angina (36 versus 86 percent, p less than 0.01), a greater prevalence of exercise-induced S-T segment depression (18 versus 45 percent, p less than 0.05), a greater number of anterior 201Tl myocardial defects (p less than 0.05); a lower radionuclide ejection fraction at rest (50.4 +/- 6.1 versus 39.6 +/- 9.3 percent, p less than 0.01) and a greater number of asynergic left ventricular segments (p less than 0.05). Thus, the occurrence of increased lung 201Tl uptake during submaximal exercise scintigraphy in the early postinfarction period is frequent and appears to be a marker of severe and functionally more important coronary artery disease associated with left ventricular dysfunction

  11. Evaluation of 201Tl stress-redistribution imaging for the detection of myocardial ischemia and assessment of its therapeutic effect (40 cases attached)

    The characteristics of 201Tl stress-redistribution imagings of 21 normal controls and 19 myocardial ischemia were reported. Normal variability of myocardial images and its influencing factors were discussed as well. All of 40 cases were also undergoing coronary arteriography (CAG), and exercise ECG. Taken the stenosis of coronary artery > 50% by CAG as the criterion of diagnosis of CHD, the sensitivity and specificity of 201Tl image were 94.7% and 100%, while as exercise ECG were 66.6% and 80.9% respectively. 2 patients with bypass surgery and 6 patients with PTCA were examined pre- and postoperatively by 201Tl images. The results indicated that this technique was noninvasive and reliable also for the assessment of their therapeutic effect and follow up studies

  12. Serial change of 123I-BMIPP SPECT imaging during recovery from stunned myocardium after acute myocardial infarction. Correlation with 201Tl and two-dimensional echocardiography

    Using 123I-β-methyl iodophenyl pentadecanoic acid (123I-BMIPP), we investigated changes in myocardial fatty acid metabolism at recovery from stunned myocardium after acute myocardial infarction (AMI), correlation with recovery of regional wall motion and thallium-201 (201Tl) distribution in particular. The subjects were 15 patients who underwent successful reperfusion therapy after the first onset of AMI. None of the patients had multi-vessel disease or ischemic episode during their clinical course. Patients underwent 123I-BMIPP scintigraphy, 201Tl scintigraphy and two-dimensional echocardiography during the acute and chronic phases. Then, we compared regional wall motion with distribution of 123I-BMIPP and 201Tl. Regional wall motion and SPECT were evaluated by the established 16 segment model. In patients, showing serial improvement in regional wall motion, there was 80.0% (8/10) showed normal 201Tl distribution during the acute phase or normalized during the chronic phase. However, distribution of 123I-BMIPP normalized only in 10.0% (1/10) of this group. In examination of each segment that showed serial improvement in regional wall motion, 92.3% (24/26) of these segments showed normal distribution of 201Tl during the acute phase or normalized distribution during chronic phase, despite distribution of 123I-BMIPP improved in only 3.8% (1/26) of these segments. These indicate that, in the process of recovery from myocardial stunning after AMI, abnormal distribution of 123I-BMIPP continued longer than abnormal distribution of 201Tl. (author)

  13. Evaluation of clinical usefulness of myocardial perfusion imaging with tetrofosmin in patients with ischemic heart disease. Comparison with [sup 201]Tl SPECT

    Yoshida, Tsuyoshi; Sasaki, Masayuki; Ichiya, Yuichi (Kyushu Univ., Fukuoka (Japan). Faculty of Medicine) (and others)

    1994-09-01

    We evaluated the clinical usefulness of [sup 99m]Tc-1, 2-bis[bis(2-ethoxyethyl)phosphino]ethane (tetrofosmin) and compared it with [sup 201]Tl. The subjects consisted of 12 patients including 8 patients with old myocardial infarction (OMI), 2 with effort angina, one with stable angina and one with myocarditis. The tetrofosmin SPECT images were obtained during exercise and at rest. The quality of tetrofosmin SPECT images was equal or slightly superior to that of [sup 201]Tl. And the sensitivity, specificity and accuracy of tetrofosmin for the detection of coronary stenosis and/or obstruction were equal to that of [sup 201]Tl. We conclude that tetrofosmin is useful in the diagnosis of ischemic heart disease. (author).

  14. {sup 123}I-MIBG myocardial scintigraphy in diabetic patients. Relationship with {sup 201}Tl uptake and cardiac autonomic function

    Nagamachi, Shigeki; Jinnouchi, Seishi; Kurose, Takeshi; Ohnishi, Takashi; Flores, L.G. II; Nakahara, Hiroshi; Futami, Shigemi; Tamura, Shozo; Matsukura, Shigeru [Miyazaki Medical Coll., Kiyotake (Japan)

    1998-12-01

    The purpose of this paper is to investigate the influence of diabetic myocardial damage (suspected myocardial damage; SMD) diagnosed by {sup 201}Tl-SPECT and diabetic cardiac autonomic neuropathy (AN) on myocardial MIBG uptake in patients with NIDDM. Eighty-seven diabetic patients divided into four subgroups: 23 with SMD (+) AN (+); 19 with SMD (+) AN (-); 27 with SMD (-) AN (+); 18 with SMD (-) AN (-), and 10 controls were studied. Both planar and SPECT images were taken at 30 minutes (early) and 3 hours (delayed) after {sup 123}I-MIBG injection. The heart to mediastinum uptake ratio (H/M) and washout ratio of {sup 123}I-MIBG (WR) were obtained from both planar images. Similarly, the difference between the {sup 201}Tl image and the {sup 123}I-MIBG image in the total uptake score (TUS) was taken as the difference in the total uptake score ({Delta}TUS) representing cardiac sympathetic denervation without SMD. On both early and delayed planar images, the mean H/M value in the subgroups of diabetic patients was significantly lower in the SMD (+) AN (+) group than in the control group, but among those subgroups, there was statistically significant difference between the SMD (+) AN (+) and SMD (-) AN (-) groups only on the delayed images. Regarding the WR value, there was no statistically significant difference among subjects. On SPECT image analysis, the diabetic subgroup with AN or SMD had statistically significant lower values for TUS than those of the control group. Among diabetics, there was a statistically significant differences between SMD [+] AN [+] and SMD [-] AN [-] on both early and delayed images. Similarly, the SMD [+] AN [-] group also had significantly lower values than those of SMD [-] AN [-] on early images. Regarding {Delta}TUS, there was a statistically significant differences between AN [+] subgroups and controls. Similarly, the mean value for {Delta}TUS was much higher in AN [+] subgroups than in AN [-] subgroups with or without SMD in diabetes

  15. [sup 123]I-MIBG myocardial scintigraphy in diabetic patients. Relationship with [sup 201]Tl uptake and cardiac autonomic function

    Nagamachi, Shigeki; Jinnouchi, Seishi; Kurose, Takeshi; Ohnishi, Takashi; Flores, L.G. II; Nakahara, Hiroshi; Futami, Shigemi; Tamura, Shozo; Matsukura, Shigeru (Miyazaki Medical Coll., Kiyotake (Japan))

    1998-12-01

    The purpose of this paper is to investigate the influence of diabetic myocardial damage (suspected myocardial damage; SMD) diagnosed by [sup 201]Tl-SPECT and diabetic cardiac autonomic neuropathy (AN) on myocardial MIBG uptake in patients with NIDDM. Eighty-seven diabetic patients divided into four subgroups: 23 with SMD (+) AN (+); 19 with SMD (+) AN (-); 27 with SMD (-) AN (+); 18 with SMD (-) AN (-), and 10 controls were studied. Both planar and SPECT images were taken at 30 minutes (early) and 3 hours (delayed) after [sup 123]I-MIBG injection. The heart to mediastinum uptake ratio (H/M) and washout ratio of [sup 123]I-MIBG (WR) were obtained from both planar images. Similarly, the difference between the [sup 201]Tl image and the [sup 123]I-MIBG image in the total uptake score (TUS) was taken as the difference in the total uptake score ([Delta]TUS) representing cardiac sympathetic denervation without SMD. On both early and delayed planar images, the mean H/M value in the subgroups of diabetic patients was significantly lower in the SMD (+) AN (+) group than in the control group, but among those subgroups, there was statistically significant difference between the SMD (+) AN (+) and SMD (-) AN (-) groups only on the delayed images. Regarding the WR value, there was no statistically significant difference among subjects. On SPECT image analysis, the diabetic subgroup with AN or SMD had statistically significant lower values for TUS than those of the control group. Among diabetics, there was a statistically significant differences between SMD [+] AN [+] and SMD [-] AN [-] on both early and delayed images. Similarly, the SMD [+] AN [-] group also had significantly lower values than those of SMD [-] AN [-] on early images. Regarding [Delta]TUS, there was a statistically significant differences between AN [+] subgroups and controls. Similarly, the mean value for [Delta]TUS was much higher in AN [+] subgroups than in AN [-] subgroups with or without SMD in diabetes

  16. assessment of the clinical role of simultaneous 99mTc-MIBI and 201Tl dual-isotopic myocardial perfusion SPECT imaging in the patients wit hypertension

    Objective: To study the clinical role of Simultaneous rest technetium-99m sestamibi (99mTc-MIBI) and stress thallium-201 (201Tl) Dual-isotopic myocardial perfusion SPECT imaging in the patients with hypertension. Methods: 116 patients with high blood pressure underwent simultaneous dual-isotopic myocardial perfusion SPECT imaging with 99mTc-MIBI and 201Tl. 99mTc-MIBI was injected at rest, 15 min later dobutamine was instilled into vein begin with 5 mg/kg/min, before and after instilling the base ECG, blood pressure, heart rate was recorded. when the maximal dose of Dobutamine was achieved, thallium-201 was injected, the dual-isotopic simultaneously SPECT imagine was performed. The stress and rest imagine was obtained. After tomographic reconstruction, the images were interpreted by two experienced observers without previous knowledge of results of other studies. Coronary angiography was performed in two weeks. All of 116 patients were found normal. Results: (1) All of 116 patients with high blood pressure were divided as three group by the course of disease: A group (20 year), 15. The heart/lung ratios of A, B, C group were 2.651±0.246, 2.546±0.231, 2.490±0.36 (mean±SD)respectively, no significant difference was noted among three group. Normal heart/lung ratios is 2.50±0.28 among of control group of 20. (2) The overall sensitivity for the dual-isotopic simultaneously myocardial SPECT imagine of high blood pressure was 46.55%(54/116). (3) Anterior, lateral, inferior, apex, interventricular septal segment were regarded as a whole segment, 111 segments display abnormal 201Tl uptake. 63, 30, 18 segments were in A, B, C group respectively, and no significant difference was noted among three group. 4 85 segments reveal reduced stressing 201Tl uptake and no typical redistribution was observed in the delay 201Tl imagines. 20, 24, 14, 12, 15 segments were in anterior, lateral, inferior, apex, interventricular septal segment respectively. 26 segments display inverse 201

  17. A new protocol of dual energy acquisition on stress 201Tl and rest 99mTc-tetrofosmin myocardial scintigraphy

    We carried out stress 201Tl (Tl) and rest 99mTc-tetrofosmin (TF) myocardial scintigraphy with dual energy acquisition in 24 patients with suspected ischemic heart disease performed coronary arteriography and elucidated the sensitivity of this method. One hour after light meal eating, TF (555 MBq) was injected intravenously at rest and after 3 minutes from injection of TF exercise or pharmacologic stress was performed. During stress Tl (111 MBq) was injected intravenously before end-point or at adequate point of pharmacologic stress. Dual energy acquisition using triple energy windows (TEW) was started after 5 minutes (early) and 4 hours (delayed) from stress. The sensitivity (Sn), specificity (Sp) and accuracy (Ac) in diagnosis of non-infarcted branches by using Tl (early)-TF (rest) and Tl (early)-Tl (delayed) were 79% vs. 53% (Sn), 78% vs. 96% (Sp) and 79% vs. 71% (Ac) respectively. Accordance of uptake score of infarcted region between TF (rest) and Tl (delayed) was 70%. In conclusion, this protocol is seemed to be useful as usual protocol for detection of myocardial ischemia and viability during about only 1 hour. (author)

  18. sup(99m)Tc-pyrophosphate and 201Tl myocardial scintigrams in a patient with myocarditis

    Myocardial necrosis in acute myocarditis was investigated by scintigraphy. sup(99m)Tc-pyrophosphate (PYP) and 201TI myocardial scintigrams were obtained on a patient with acute myocarditis due to mycoplasma infection. sup(99m)Tc-PYP myocardial scintigrams in the acute stage demonstrated grade 2+ findings, which remained until the chronic stage. 201TI myocardial scintigrams in the acute stage revealed impaired perfusion restricted to the posterolateral wall, and this decrease continued through the chronic stage. It was concluded that both of sup(99m)Tc-PYP and 201TI myocardial scintigrams can reveal abnormality of acute myocarditis. (Ueda, J.)

  19. Assessment of myocardial damage and metabolic disorder in the left ventricle in patients with mitral stenosis using 201Tl and 123I-BMIPP myocardial SPECT

    This study was designed to evaluate the myocardial damage and metabolic disorder of the left ventricle in patients with mitral stenosis. We studied 15 patients with mitral stenosis. Their grade of chronic heart failure using New York Heart Association classification were class I: 5 patients, class II: 5, class III: 3, class IV: 2, respectively. The severely stenotic group (valve area 2) included 6 patients, mildly stenostic group (1.5 cm2≤ valve area 2) included 9. A 111 MBq of 123I-BMIPP was intravenously injected at rest, SPECT images were obtained at 15 min and 3 hours after injection. A 111 MBq of 201Tl was intravenously injected at rest, and SPECT images were obtained at 15 min after injection. Washout rate (WR) of 123I-BMIPP from the whole left ventricle was obtained using polar maps. The concentration of norepinephrine (NE: pg/ml) in the blood at rest was measured. The mean values of pulmonary artery pressure was measured in ten patients using Swan-Ganz catheter. 123I-BMIPP myocardial SPECT and measurement of NE were reexamined in 5 patients after mitral valvuloplasty. NE values were 476±72 and 793±286 in classes I+II and III+IV, respectively. NE values was increased in the severe heart failure group (p201Tl and 123I-BMIPP myocardial SPECT. Three patients showed slightly reduced uptake on both 201Tl and 123I-BMIPP myocardial SPECT. WR was 27.2±4.8% and 44.3±6.7% in class I+II and class III+IV, respectively. WR was increased in severe heart failure group (p<0.05). WR was 27.8±6.0% and 41.3±9.4% in the mildly and severely stenotic group, respectively. WR was increased in the severely stenotic group (p<0.05). NE was correlated with WR (p<0.001). In patients with mitral valvuloplasty, WR was 44.3±6.7% and 31.4±4.7% before and after mitral valvuloplasty, respectively. NE values were 857±266 and 574±165, respectively. Both WR and NE were decreased after mitral valvuloplasty (p<0.01). In patients with mitral stenosis, WR was increased in the severe

  20. Assessment of myocardial perfusion and cardiac sympathetic nerve dysfunction in patients with sick sinus syndrome. Evaluation of coronary hemodynamics and 201TlCl/123I-MIBG myocardial SPECT

    To clarify the coronary hemodynamics, myocardial perfusion and cardiac sympathetic nerve function in patients with sick sinus syndrome (SSS), we performed left coronary digital subtraction angiography (DSA) in 41 patients, exercise 201TlCl-myocardial scintigraphy (planar and SPECT) in 69 patients, and 201TlCl/123I-MIBG myocardial dual SPECT in 13 patients without significant organic coronary stenosis. Coronary artery spasm was documented on coronary angiography in 25/43 (58%) patients with SSS by ergonovine provocation test. Compared with normals, patients with SSS demonstrated prolongation of left coronary circulation time (CCT) on own heart beats and right atrial pacing. We suspected that prolonged CCT may be induced by increased peripheral coronary vascular resistance and impaired coronary micro-circulation in patients with SSS. Forty-two patients (60.9%) developed exercise-induced 201Tl-myocardial perfusion defect on SPECT images. On myocardial dual SPECT images, 11/13 (85%) patients showed localized myocardial low uptake in 123I-MIBG-SPECT images. In eight patients with normal findings on 201Tl-SPECT, six patients showed abnormality on 123I-MIBG-SPECT. We suspected that coronary vasospasm, impaired coronary micro-circulation and cardiac sympathetic nerve dysfunction are taken a part of pathophysiology in SSS (decreased β-adrenergic receptor of peripheral coronary arteries?). (author)

  1. Quantitative analysis of exercise 201Tl myocardial emission CT in patients with coronary artery disease

    The clinical usefulness of quantitative analysis of exercise thallium-201 myocardial emission computed tomography (ECT) was evaluated in coronary artery disease (CAD). The subjects consisted of 20 CAD patients and five normal controls. All CAD patients underwent coronary angiography. Tomographic thallium-201 myocardial imaging was performed with a rotating gamma camera, and long-axial and short-axial myocardial images of the left ventricle were reconstructed. The tomographic images were interpreted quantitatively using circumferential profile analysis. Based on features of regional myocardial thallium-201 kinetics, two types of abnormalities were studied: (1) diminished initial distribution (stress defect) and (2) slow washout of thallium-201, as evidenced by patients' initial thallium-201 uptake and 3-hour washout rate profiles which fell below the normal limits, respectively. Two diagnostic criteria including the stress defect and a combination of the stress defect and slow washout were used to detect coronary artery lesions of significance (>=75 % luminal narrowing). The ischemic volumes were also evaluated by quantitative analysis using thallium-201 ECT. The diagnostic accuracy of the stress defect criterion was 95 % for left anterior descending, 90 % for right, and 70 % for left circumflex coronary artery lesions. The combined criteria of the stress defect and slow washout increased detection sensitivity with a moderate loss of specificity for identifying individual coronary artery lesion. A relatively high diagnostic accuracy was obtained using the stress defect criterion for multiple vessel disease (75 %). Ischemic myocardial volume was significantly larger in triple vessel than in single vessel disease (p < 0.05) using the combined criteria. It was concluded that quantitative analysis of exercise thallium-201 myocardial ECT images proves useful for evaluating coronary artery lesions. (author)

  2. Quantitative analysis of 201Tl myocardial scintigraphy in ischemic heart disease

    Seventy two patients with myocardial infarction (MI), 13 with angina pectoris (AP), and 10 without ischemic heart disease were investigated by the quantitative analysis of Tl-201 myocardial scintigraphy. In the group of MI patients, defects of Tl-201 uptake was observed in 89.7% on planar images and 91.2% on SPECT images. Patients without Tl defect had no evidence of abnormal Q wave. For 62 patients undergoing coronary angiography and left ventriculography, defect size was well consistent with culprit lesions, particularly in the left anterior descending artery. Both extent score (ES) and severity score (SS), obtained by planar images and bull's-eye SPECT images, were significantly correlated with peak creatine phosphokinase (CPK) in plasma and ejection fraction. Redistribution magnitudes of Tl-201 uptake (ΔES and ΔSS) 3 hr after exercise were much greater in patients with exercise-induced ST depression than those with either unchanged or elevated ST segments. Some of the patients with no evidence of ST depression had high ΔES and ΔSS. Similarly, these indices were high in patients with residual stenosis of culprit coronary artery. Six MI patients treated with percutaneous transluminal coronary angioplasty (PTCA) were found to have the decrease in both ΔES and ΔSS. Decreased % Tl-201 uptake and % washout rate were also improved by PTCA. Similar improvement in these indices was seen in 15 AP patients successfully treated with PTCA. Reverse redistribution (RR) was seen in 5 patients with no significant stenosis of culprit coronary artery. Three other MI patients had also RR after PTCA. Areas corresponding to RR had higher washout rate than the other areas. In conclusion, quantitative analysis of Tl-201 myocardial scintigraphy seems to be useful in estimating infarction size and viable myocardium, as well as in evaluating the improvement of myocardial ischemia after PTCA. (N.K.)

  3. Assessment of 201Tl myocardial SPECT reinjected at 24 hours after stress imaging

    To improve the quality of 24 hours delayed images (24 DL) of stress thallium-201 myocardial SPECT, reinjection was performed at 24 hours later (24 RI), and the results were compared with those of 24 DL. A total of 45 patients were studied, including 18 patients in 24 DL, 27 patients in 24 RI. All of them showed persistent defect or incomplete redistribution on the routine stress and 3 hours delayed SPECT scans. In 24 RI, 37 MBq of thallium-201 was reinjected at 24 hours later. Myocardial count of 24 DL was about 1/4 of stress image, while 24 RI was about 1/2. Quality of 24 RI image was nearly equal to 3 hours delayed image. Of regions without redistribution on 3 hours delayed image, 5 (36%) regions showed new redistribution at 24 RI. Of regions incomplete redistribution, 6 (25%) regions showed further redistribution. Compared with 24 DL, the frequency of redistribution tended to be higher in this protocol than that of the 24 DL (11%, 17% respectively). In conclusion, the reinjection on 24 hours delayed imaging was considered to be useful to evaluate viability of myocardium in patients with CAD. (author)

  4. Dobutamine stress thallium-201 single-photon emission tomography versus echocardiography for evaluation of the extent and location of coronary artery disease late after myocardial infarction

    Elhendy, A.; Bax, J.J.; Domburg, R.T. van; Cornel, J.H.; Roelandt, J.R.T.C. [Thoraxcenter, Univ. Hospital Rotterdam-Dijkzigt, Rotterdam (Netherlands); Valkema, R.; Reijs, A.E.M.; Krenning, E.P. [Dept. of Nuclear Medicine, University Hospital Rotterdam-Dijkzigt, Rotterdam (Netherlands)

    1999-05-01

    Dobutamine stress echocardiography and thallium-201 myocardial perfusion scintigraphy are clinically useful methods for the evaluation of coronary artery disease (CAD). However, the relative merits of these imaging modalities in the evaluation of the extent of CAD after myocardial infarction have not been well studied. The aim of this study was to compare the accuracy of dobutamine stress echocardiography and simultaneous {sup 201}Tl single-photon emission tomography (SPET) imaging for the diagnosis and localization of CAD late after acute myocardial infarction. Dobutamine (up to 40 {mu}g kg{sup -1} min{sup -1})-atropine (up to 1 mg) stress echocardiography in conjunction with stress-reinjection {sup 201}Tl SPET was performed for the evaluation of myocardial ischaemia in 90 patients with previous myocardial infarction who underwent coronary angiography. Significant CAD was predicted on bases of myocardial ischemia (new or worsening wall motion abnormalities on echocardiography and reversible perfusion defects on {sup 201}Tl SPET). Significant CAD ({>=} 50% luminal diameter stenosis) was detected in 73 (81%) patients. The sensitivity, specificity and accuracy of echocardiography in detecting remote ischaemia for the diagnosis of remote CAD (present in 53 patients) were, respectively, 79% (CI 70%-88%), 85% (CI 77%-93%) and 81% (CI 73%-90%), while the corresponding figures for {sup 201}Tl SPET were 75% (CI 66%-85%), 78% (CI 69%-87%) and 76% (CI 67%-86%) respectively (P = NS vs echocardiography). The sensitivity, specificity and accuracy of echocardiography in detecting peri-infarction ischaemia for the diagnosis of infarct-related artery stenosis (present in 70 patients) were, rspectively, 77% (CI 68%-86%), 85% (CI 78%-92%) and 79% (CI 70%-87%) while the corresponding figures for {sup 201}Tl SPET were 73% (CI 64%-82%), 85% (CI 78%-92%) and 76% (CI 67%-84%) respectively (P = NS vs echocardiography). The agreement between the two methods for the diagnosis of peri

  5. Clinical study of right ventricular visualization by 201Tl myocardial scintigraphy

    Thallium-201 myocardial scans of 65 patients were retrospectively reviewed to evaluate the ability to detect right ventricular (RV) overloading. The degree of right ventricular visualization (RVV) was graded as a scale of (-)-(+++) according to RV uptake of the tracer: (-) = none; (+-) = slight RVV; (+) = less than left ventricular visualization (LVV); (++) = equal to LVV; (+++) = greater than LVV. Increased RV uptake was frequently seen in patients with chronic lung disease or congenital heart disease. The best projection angle for RVV was 60 deg in patients with grades (+-) and (+). The degree of RVV was compared with the data from cardiac catheterization performed in 25 of the patients. More increased uptake of the tracer was significantly associated with higher values of RV systolic pressure, pulmonary arterial systolic pressure, mean pulmonary arterial pressure, and pulmonary arterial resistant index. RV end-diastolic pressure, cardiac index, RV work index, RV stroke-work index, and heart rate were independent of the intensity of tracer uptake. The ratio of the RV to the left ventricle was significantly higher with increasing tracer uptake, although there was no significant difference between the groups with (+-) and grade (+). It was also correlated well with RV hemodynamic parameters. (Namekawa, K.)

  6. Importance of 201Tl scintigraphy during exercise for diagnosis of silent myocardial ischemia

    Using thallium scintigraphy during exercise (TSE), suspect silent myocardial ischemia (SIM) was diagnosed in subjects without angina pectoris. 21 active pilots with suspect SIM were examined after previous exercise ECG as well as 33 patients with diabetes type I and II. In six pilots (28.6%) TSE showed accumulation defects suggesting ischemic disorders of the large coronary arteries. Five pilots showed obvious depressions of the ST segment in ECG during submaximal exercise TSE. In another group of five pilots small depressions of the ST segment were associated with normal TSE. Twelve diabetic patients (36.4%) had minor accumulation defects on TSE. Only two showed a ST depression under 2 mm in ECG during TSE. Based on data in the literature suggesting higher sensitivity and specificity of exercise thallium scintigraphy as compared with exercise ECG and the possibility of a false positive diagnosis of SIM from exercise ECG alone, it is recommended to also use TSE. A more detailed diagnosis of SIM is essential not only with regard to the assessment of work capacity but also for a long-term follow-up of patients with SIM for assessment of its incidence, impact and prognosis in the population. (author). 4 figs., 4 tabs., 25 refs

  7. Dual myocardial scintigraphic imaging using 123I-BMIPP and 201Tl in patients with Duchenne's progressive muscular dystrophy

    Dual single photon emission computed tomography (SPECT) was performed in 30 patients with Duchenne's muscular dystrophy (DMD) using 201 thallium (Tl) for myocardial perfusion 123I-β-methyl-p-iodophenylpentadecanoic acid (BMIPP) for myocardial fatty acid metabolism scintigraphy. The left ventricle was divided into 9 regions, and accumulation of the radiotracers was assessed visually for each region to calculate defect score for each tracer. There was some degree of decrease in the myocardial accumulation of both tracers in all DMD patients. Reduced accumulation was most common at the apex (BMIPP, 70%; Tl, 63%), followed by the posterior wall, lateral wall, and anterior wall. It was less common on the apical side of the ventricular septum for both tracers (BMIPP, 3%; Tl, 17%). Accumulation of Tl was lower than BMIPP in 18/30 patients (60%) and higher in 9 (30%), while both tracers showed equal accumulation in 3 (10%). BMIPP showed higher accumulation than Tl in all regions but the septum. A significant negative correlation was found between the defect scores for both tracers and the left ventricular ejection fraction (LVEF) (r=-0.629 for Tl; r=-0.567 for BMIPP). The strongest negative correlation was that between the sum of the Tl and BMIPP defect scores and the LVEF (r=-0.681). Dual SPECT myocardial scintigraphy with Tl and BMIPP provided an accurate evaluation of the progression of cardiac lesions in DMD by detecting abnormalities of the myocardial metabolism of each substance thereby enabling the assessment of left ventricular function. (author)

  8. 201Tl labelled myocardium tomoscanning

    A new device, the J and P Tomoscanner, enables us to obtain the transverse scintigraphic section of any organ labelled by a single photon emitting radionuclide. For the time being, this technique has been used mainly for brain and liver studies. This work explores the ability of this tomograph to furnish sections of the 201Tl labelled myocardium by comparing them with the scintillation gamma-camera images. Towards this aim, witnesses and patients with documented anterior or lateral infarctus have been studied. Our actual results show a high correlation between the two explorations. But, by means of the section, both the site and size of the necrosis are visualized. However, only a single tomographic image was obtained in each patient because of the time necessary for its retranscription on paper. In the near future, when it will be possible to perform routinely several sections, a better size estimation will be possible

  9. Comparative study of dobutamine stress echocardiography and dual single-photon emission computed tomography (Thallium-201 and I-123 BMIPP) for assessing myocardial viability after acute myocardial infarction

    Yasugi, Naoko; Hiroki, Tadayuki [Fukuoka Univ., Chikushino (Japan). Chikushi Hospital; Koyanagi, Samon [National Fukuoka-Higashi Hospital, Koga (Japan). Clinical Research Inst.; Ohzono, Keizaburo; Sakai, Kikuo; Matsumoto, Takahiro; Sako, Shigeki; Homma, Tomoki; Azakami, Shirou [National Kyushu Medical Center, Fukuoka (Japan)

    2002-12-01

    Discordance between the {sup 123}I-labelled 15-iodophenyl-3-R, S-methyl pentadecanoic acid (BMIPP) and {sup 201}Tl findings may indicate myocardial viability (MV). This study compared dobutamine stress echocardiography (DSE) and single-photon emission computed tomography (SPECT) using the dual tracers for assessment of MV and prediction of functional recovery after acute myocardial infarction (AMI). DSE and dual SPECT were studied in 35 patients after AMI, of whom 28 underwent percutaneous coronary intervention in the acute stage. Dual SPECT was performed to compare the defect score of BMIPP and {sup 201}Tl. The left ventricular wall motion score (WMS) was estimated during DSE and 6 months later to assess functional recovery of the infarct area. The rate of agreement of MV between dual SPECT and DSE was 89% (p<0.01), and the sensitivity and specificity of DSE for dual SPECT in MV assessment was 86% and 93%, respectively. The positive and negative predictive values for functional recovery by dual SPECT were 76% and 67%, respectively, and by DSE were 90% and 79%, respectively. Four of 5 patients with positive MV by dual SPECT, but without functional recovery, had residual stenosis of the infarct-related artery. The WMS and defect scores of BMIPP and {sup 201}Tl were significantly smaller in patients with functional recovery than in those without. Assessment of MV using DSE concords with the results of dual SPECT in the early stage of AMI. DSE may have a higher predictive value for long-term functional recovery at the infarct area. However, a finding of positive MV by dual SPECT, without functional recovery, may indicate residual stenosis of the infarct-related artery, although the number of cases was small. Combined assessment by dual SPECT and DSE may be useful for detecting MV and jeopardized myocardium. Furthermore, the results suggest that functional recovery of dysfunctional myocardium may depend on the size of the infarct and risk area. (author)

  10. Correlation of left ventricular dyssynchrony with myocardial stunning using dual single photon emission computed tomography of 123iodine-β-methyl iodophenyl pentadecanoic acid and 201thallium scintigraphy after reperfusion therapy

    Left ventricular (LV) dyssynchrony after reperfusion therapy has been closely examined as a cause of chronic remodeling, but the details have not been clarified. The present study measured LV dyssynchrony appearing immediately after reperfusion therapy using real-time three-dimensional echocardiography (RT-3DE), and assessed the significance of this phenomenon in relation to dual single photon emission computed tomography (SPECT) of 123iodine β methyliodophenyl pentadecanoic acid (123I-BMIPP) and 201thallium (201Tl). Subjects comprised 58 patients with first-time acute myocardial infarction who received reperfusion therapy and underwent RT-3DE and dual SPECT of 123I-BMIPP and 201Tl within two weeks of onset. Two dyssynchrony parameters were measured using RT-3DE in the acute phase and six months later. After evaluating the correlation of these dyssynchrony parameters to resting 201Tl uptake, 201Tl washout, 123I-BMIPP uptake, and 201Tl-123I-BMIPP discrepancy (Tl-BMIPP discrepancy), we compared scintigraphic parameters in the chronic phase between groups with improved dyssynchrony and those without. Acute dyssynchrony exhibited a significant positive correlation to Tl-BMIPP discrepancy and it was significantly increased in the group with improved dyssynchrony in the chronic phase, revealing close relationship between dyssynchrony and Tl-BMIPP discrepancy. Then the subjects were divided into positive Tl-BMIPP discrepancy and negative discrepancy groups, and the parameters of cardiac function were compared between them. In the chronic phase, improved cardiac function was observed in the group with positive Tl-BMIPP discrepancy compared to negative discrepancy. LV dyssynchrony after reperfusion therapy correlates positively with Tl-BMIPP discrepancy, reflecting acute myocardial stunning, in which ventricular contraction improves during the chronic phase. (author)

  11. Effects of ischemia-reperfusion injury on myocardial single pass extraction and retention of Cu-PTSM in perfused rat hearts: comparison with [sup 201]Tl and [sup 14]C-iodoantipyrine

    Wada, Kouichi; Fujibayashi, Yasuhisa; Taniuchi, Hideyuki; Tajima, Naoyuki; Yokoyama, Akira (Kyoto Univ. (Japan). Faculty of Pharmaceutical Sciences); Tamaki, Nagara; Konishi, Junji (Kyoto Univ. (Japan). School of Medicine)

    1994-05-01

    The effects of ischemia-reperfusion-induced myocardial damage on the single pass extraction and retention of [sup 64]Cu-pyruvaldehyde-di-(N[sup 4]-methylthiosemicarbazone) ([sup 64]Cu-PTSM) in perfused rat hearts were compared to these effects on that of [sup 201]Tl and [sup 14]C-iodoantipyrine. [sup 201]Tl and [sup 14]C-iodoantipyrine did not show significant changes, but in the case of [sup 64]Cu-PTSM, the single pass extraction and retention was reduced with reperfusion. These findings indicate that ischemia-reperfusion-induced myocardial damage decrease the generator-produced [sup 62]Cu-labeled [sup 62]Cu-PTSM extraction and retention, and that [sup 62]Cu-PTSM might have potential not only as a blood flow tracer but also as a functional tracer. (author).

  12. Quality control 201TlCl solution obtained at IPEN-CNEN/SP through the direct method of 201Tl preparation

    The radiopharmaceutical 201TlCl is used in Nuclear medicine for myocardial visualization. The solution of 201TlCl was prepared using 201Tl obtained by irradiating a natural mercury target with protons. This radionuclide was subjected to different quality control processes to verify the purity required for its use in Medicine. Some of these controls concerned the determination of 200Tl, 201Tl and 202Tl; the chemical identification of 201Tl+1; the hydrazine concentration, mercury contamination and the presence of phosphate. Furthermore, the biologic distribution in Wistar rats and tests for sterility, pyrogens and for toxicity were carried out. It was verified that the solution obtained was in the form of thallous chloride. This radiopharmaceutical can give a good heart image in animals but due to the contamination of 201Tl with 200Tl and 202Tl its use in human beings is not possible unless enriched 202Hg is used as target of irradiation. (author)

  13. Coronary spasm: 201Tl scintiscanning following pharmacological provocation

    According to the authors' experience so far, 201Tl myocardial scintiscanning is a sufficiently sensitive non-invasive method for detection of coronary vasospasm provoked by ergotamine administration. Mild incomplete and asymptotic forms of coronary vasospasm were detected by scintiscanning. Indications for myocardial scintiscanning of ergotamine-provoked vasospasm are: Cases of angina pectoris at rest in which electrocardiograms during spasm are not available; elleviated symptoms after nitroglycerine administration; exercise electrocardiograms without any sign of ischaemia; negative results of exercise 201Tl myocardial scintiscanning. (orig.)

  14. Diagnosis of acute myocardial infarction using dual SPECT (99mTc PYP and 201Tl Cl) method

    We investigated the usefulness of the dual SPECT method with the Tc-99m and Tl-201 in comparison with the conventional Tc-99m planar method. Myocardial scintigraphy was performed in 57 patients with acute myocardial infarction; 30 were assessed by the conventional planar method and 27 by the dual SPECT method. The accumulation ratio of Tc-99m (%Tc) by the dual SPECT method was calculated from the coronal image and was compared with the serum values of total CPK, peak CPK, total CPK-MB, and peak CPK-MB obtained from serial sampling and the LVEF obtained by a left ventriculography a month later. The sensitivity for diagnosis of myocardial infarction was 73.3% by the planar method and 88.9% by the dual SPECT method. The infarct sites were identified in 61.5% of the antero-septal lesion, in 35.7% of the infero-posterior lesion and in 66.7% of the lateral lesion using the planar method, while using the dual SPECT method were 100% identification for both antero-septal and lateral lesions, and 75% for the infero-posterior lesion. The highest correlation, with a rate of 0.854, was between the %Tc and the total CPK. The %Tc also showed a positive correlation with peak CPK (r=0.798), with total CPK-MB (r=0.792) and with peak CPK-MB (r=0.751) (p<0.01). The LVEF had a tendency to decrease as %Tc exceeded 30%. The dual SPECT method was superior to the conventional planar method in detecting, in identifying the site and in evaluating the size of myocardial infarction. It also showed a high correlation between the %Tc and the LVEF at chronic stage of myocardial infarction. (author)

  15. Comparison of adenosine and exercise stress 201Tl myocardial perfusion imaging for diagnosing coronary heart disease in women

    Objective: To compare the diagnostic value of adenosine and exercise stress myocardial perfusion imaging (MPI) for detecting coronary heart disease (CHD) in women. Methods: One hundred and thirty-eight patients with CHD were randomly divided into two groups: adenosine stress group (n=69)and exercise stress group (n=69). All patients underwent myocardial SPECT evaluation. Coronary angiography (CAG), referred as 'gold standard' , was performed in each patient within 1 week before or after MPI. The diagnostic value of the two stress MPI was compared with χ2 test or Fisher's exact test. Results: In adenosine stress group, the sensitivity, negative predictive value and accuracy were 88.2% (45/51), 72.7% (16/22), 88.4% (61/69), respectively, which were not significantly different from those of the exercise stress group (91.7% (44/48), 66.7% (8/12), 81.2% (52/64); χ2 =0.571, 0.714, 0.249, P>0.05). However, the false positive rate of adenosine stress (11.1%, 2/18) was significantly lower than that of exercise stress (50.0%, 8/16), P=0.023. Conclusions: Adenosine and exercise stress MPI have similar value for CHD diagnosis in women, however, adenosine stress MPI may have an advantage of low false positive rate. (authors)

  16. Synthesis and in vivo evaluation of {sup 201}Tl(III)-DOTA complexes for applications in SPECT imaging

    Hijnen, Nicole M.; Vries, Anke de [Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands); Blange, Roy [Department of Biomolecular Engineering, Antwerp University, 2610 Antwerp (Belgium); Burdinski, Dirk [Department of Biomolecular Engineering, Philips Research, 5656 AE Eindhoven (Netherlands); Gruell, Holger, E-mail: h.gruell@tue.n [Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands); Department of Biomolecular Engineering, Philips Research, 5656 AE Eindhoven (Netherlands)

    2011-05-15

    Introduction: The aim of this study was to assess the use of {sup 201}thallium{sup 3+} ({sup 201}Tl{sup 3+}) as a radiolabel for nuclear imaging tracers. Methods for labeling of 1,4,7,10-tetraazacyclododecane-N,N',N'',N''' tetraacetic acid (DOTA) and diethylenetriaminepentaacetic acid (DTPA) chelators with {sup 201}Tl{sup 3+} were investigated, and the levels of stability of these chelates were tested in vitro and in vivo. Methods: {sup 201}Tl(I)Cl was treated with hydrochloric acid and ozone to form {sup 201}Tl(III)Cl{sub 3}. The procedure for labeling of DOTA and DTPA was optimized, testing different buffer solutions and pH values. The stability levels of {sup 201}Tl(III)-DOTA and {sup 201}Tl(III)-DTPA were assessed in buffer, mouse serum and human serum (1:1, v/v) at a temperature of 310 K for 48 h. Subsequently, in vivo stability studies with {sup 201}Tl(III)-DOTA were performed, comparing the biodistribution of {sup 201}Tl(III)-DOTA with that of {sup 201}Tl(I)Cl in a single-isotope study and with that of {sup 177}Lu(III)-DOTA in a dual-isotope single photon emission computed tomography study. Results: {sup 201}Tl(III)-DTPA, {sup 201}Tl(III)-DOTA and {sup 177}Lu(III)-DOTA were prepared with >95% radiochemical purity. While {sup 201}Tl(III)-DOTA showed a prolonged level of stability in buffer and serum, {sup 201}Tl was quickly released from DTPA in serum. Apart from some urinary excretion, the biodistribution of DOTA-chelated {sup 201}Tl{sup 3+} was similar to that of free (ionic) {sup 201}Tl{sup +} and did not match the biodistribution of {sup 177}Lu(III)-DOTA. This indicated a limited stability of {sup 201}Tl(III)-DOTA complexes in vivo. Conclusion: Despite promising results on the labeling and in vitro stability of {sup 201}Tl(III)-DOTA, our in vivo results indicate that the integrity of {sup 201}Tl(III)-DOTA decreases to <20% during the time required for urinary excretion, thereby limiting the use of {sup 201}Tl{sup 3+} as a

  17. Synthesis and in vivo evaluation of 201Tl(III)-DOTA complexes for applications in SPECT imaging

    Introduction: The aim of this study was to assess the use of 201thallium3+ (201Tl3+) as a radiolabel for nuclear imaging tracers. Methods for labeling of 1,4,7,10-tetraazacyclododecane-N,N',N'',N''' tetraacetic acid (DOTA) and diethylenetriaminepentaacetic acid (DTPA) chelators with 201Tl3+ were investigated, and the levels of stability of these chelates were tested in vitro and in vivo. Methods: 201Tl(I)Cl was treated with hydrochloric acid and ozone to form 201Tl(III)Cl3. The procedure for labeling of DOTA and DTPA was optimized, testing different buffer solutions and pH values. The stability levels of 201Tl(III)-DOTA and 201Tl(III)-DTPA were assessed in buffer, mouse serum and human serum (1:1, v/v) at a temperature of 310 K for 48 h. Subsequently, in vivo stability studies with 201Tl(III)-DOTA were performed, comparing the biodistribution of 201Tl(III)-DOTA with that of 201Tl(I)Cl in a single-isotope study and with that of 177Lu(III)-DOTA in a dual-isotope single photon emission computed tomography study. Results: 201Tl(III)-DTPA, 201Tl(III)-DOTA and 177Lu(III)-DOTA were prepared with >95% radiochemical purity. While 201Tl(III)-DOTA showed a prolonged level of stability in buffer and serum, 201Tl was quickly released from DTPA in serum. Apart from some urinary excretion, the biodistribution of DOTA-chelated 201Tl3+ was similar to that of free (ionic) 201Tl+ and did not match the biodistribution of 177Lu(III)-DOTA. This indicated a limited stability of 201Tl(III)-DOTA complexes in vivo. Conclusion: Despite promising results on the labeling and in vitro stability of 201Tl(III)-DOTA, our in vivo results indicate that the integrity of 201Tl(III)-DOTA decreases to 201Tl3+ as a radiolabel for tracer imaging.

  18. Computer-aided semi-quantitative myocardial scintiscanning using 201-Tl in routine examinations to diagnose coronary heart disease. Rechnerunterstuetzte semiquantitative 201-Tl-Myokardszintigraphie in der Roentgendiagnostik der koronaren Herzerkrankung

    Schumacher, M.

    1983-01-01

    Thallium-201 is generally used for intravenous myocardial scintiscanning. In the 42 patients investigated during the study, the sensitivity of this method in the diagnosis of reduced myocardial perfusion was judged to be superior to that of exercise electrocardiography. The most reliable conclusions could, however, be drawn from the combined results of both these non-invasive techniques. Coronary angiography was carried out for reasons of comparison and proved that the method under investigation, even though showing an extremely high sensitivity, was less satisfactory as regards specifity. Myocardial scintiscanning using thallium-201 constitutes the only non-invasive technique suitable for the evaluation of cardial microcirculation. It must therefore be regarded as an ideal diagnostic tool to be used in combination with coronary angiography which, in turn, provides evidence of macroscopic changes. Moreover, myocardial scintiscanning using thallium-201 still remains the only procedure permitting acute myocardial infarction to be detected within the first few hours following the incident. (TRV).

  19. Assessment of coronary hemodynamics and myocardial perfusion in patients with syndrome X by digital subtraction angiography and 201Tl-myocardial scintigraphy

    To evaluate coronary hemodynamics and myocardial perfusion, left coronary digital subtraction angiography (DSA) and Tl-201 myocardial scintigraphy were performed in patients with syndrome X. The coronary circulation time (CCT) was significantly prolonged after the injection of isosorbide dinitrate and contrast medium i.c. Apical T1/2 was also prolonged on ergonovine malate provocation test. We suspected that the vascular response of the coronary peripheral artery was impaired, and microvascular spasm probably existed in patients with syndrome X. The prevalence of abnormal myocardial perfusion defect on exercise Tl-201 SPECT in syndrome X was very high, and coronary hemodynamics was significantly disturbed in the group of syndrome X with abnormal Tl-201 SPECT. Tl-201 lung/heart count ratio significantly increased in syndrome X on treadmill test. Because of this, exercise induced left ventricular dysfunction was suspected. We concluded that the main pathophysiological finding of impaired coronary circulation in syndrome X was microvascular spasm. (author)

  20. The new method of evaluation for the regional myocardial function using the regional wall thickening curve obtained by ECG-gated 201Tl planar myocardial scintigraphy

    A new method was developed for obtaining an increase rate of regional myocardial systolic wall thickness (%WT) in ECG-gated Tl-201 myocardial scintigraphy. Its value was assessed in the clinical setting in comparison with %WT obtained by echocardiography. The subjects were a total of 18 patients with cardiac diseases, including angina pectoris (7), hypertension (3), dilated cardiomyopathy (4), aortic valve stenosis (2), aortic valve regurgitation (one) and sick sinus syndrome (one). Left ventricular septal and posterolateral segments were defined as regions of interest (ROI) on LAO 45deg planar images to correspond to the sites on echocardiographic left ventricular short axial M mode images. In addition, rectangular ROI, which directly crossed the ventricular wall, was assigned to determine changes in myocardial wall thickness, whereby time-activity curve (TAC) was prepared. TAC obtained so far was analogous to that obtained by ultrasound crystal method in an animal experiment. Thus the TAC was supposed to reflect changes in regional myocardial wall thickness. Furthermore, enddiastolic count (EDC) and endsystolic count (ESC) were obtained. %WT was obtained by a formula of (ESC - EDC)/EDC*100. %WT obtained in this way correlated positively with that obtained by echocardiography, for both septal segment (r=0.78) and posterolateral segment (r=0.77). These findings suggested that the regional wall thickening curve can be used in the clinical setting. (N.K.)

  1. Clinical evaluation of the ipsilateral lung uptake of 201TlCl in spontaneous pneumothorax

    A case of re-expansion pulmonary edema following the treatment of spontaneous pneumothorax was reported, and in 3 other cases of this disease, perfusion lung scintigraphy with sup(99m)Tc-MAA and myocardial scintigraphy with 201TlCl were performed in order to evaluate the regional pulmonary arterial perfusion and lung uptake of 201Tl. The perfusion decrease and the marked uptake of 201Tl were observed in the ipsilateral lung of 2 cases. In a previous study, we reported that diffuse bilateral lung uptake of 201Tl, which was distributed in more than 90% of the extravascular space of the lung, was observed in various cases with heart disease, diffuse interstitial pneumonia etc. Therefore, it seems that ipsilateral lung in cases with spontaneous pneumothorax may be accompanied with a subclinical increased vascular permeability and abnormal accumulation of interstitial fluid. Thus patients with spontaneous pneumothorax will be predisposed to re-expansion pulmonary edema. (author)

  2. Clinical evaluation of the ipsilateral lung uptake of /sup 201/TlCl in spontaneous pneumothorax

    Fujii, T.; Hirayama, J.; Kanai, H.; Kanbayashi, T.; Mimura, N.; Amamiya, H. (Shinshu Univ., Matsumoto, Nagano (Japan). Faculty of Medicine)

    1982-08-01

    A case of re-expansion pulmonary edema following the treatment of spontaneous pneumothorax was reported, and in 3 other cases of this disease, perfusion lung scintigraphy with sup(99m)Tc-MAA and myocardial scintigraphy with /sup 201/TlCl were performed in order to evaluate the regional pulmonary arterial perfusion and lung uptake of /sup 201/Tl. The perfusion decrease and the marked uptake of /sup 201/Tl were observed in the ipsilateral lung of 2 cases. In a previous study, we reported that diffuse bilateral lung uptake of /sup 201/Tl, which was distributed in more than 90% of the extravascular space of the lung, was observed in various cases with heart disease, diffuse interstitial pneumonia etc. Therefore, it seems that ipsilateral lung in cases with spontaneous pneumothorax may be accompanied with a subclinical increased vascular permeability and abnormal accumulation of interstitial fluid. Thus patients with spontaneous pneumothorax will be predisposed to re-expansion pulmonary edema.

  3. Usefulness of 201Tl SPECT in the evaluation of treatment effect for primary lung cancer

    Thallium-201 single photon emission computed tomography (201Tl SPECT) was performed on 20 patients with primary lung cancer before and after treatment (radiotherapy alone or combination of chemotherapy and radiotherapy). They were divided into early recurrence group and no recurrence group by presence of local tumor regrowth within 6 months after treatment. Retention index (Ret. I) after treatment was significantly lower (p201Tl SPECT indicated viability of residual mass, so it was useful in the evaluation of treatment effect for primary lung cancer. (author)

  4. Standardization and decay scheme of 201Tl

    An intercomparison exercise was conducted among three national standards laboratories and a commercial supplier to determine the degree of agreement between directly determined values of the activity concentration of a solution of 201Tl. The γ-ray emission probabilities of 201Tl were also determined, providing an emission probability for the 167.4 keV γ ray of 0.1000±0.0006. (author)

  5. Thallium-201 single photon emission computed tomography (SPECT) in patients with Duchenne's progressive muscular dystrophy. A histopathologic correlation study

    The pathomorphologic mechanism responsible for abnormal perfusion imaging during thallium-201 myocardial single photon emission computed tomography (201Tl-SPECT) in patients with Duchenne's progressive muscular dystrophy (DMD) was investigated. Hearts from 7 patients with DMD were evaluated histopathologically at autopsy and the results correlated with findings on initial and delayed resting 201Tl-SPECT images. The location of segments with perfusion defects correlated with the histopathologically abnormal segments in the hearts. Both the extent and degree of myocardial fibrosis were severe, especially in the posterolateral segment of the left ventricle. Severe transmural fibrosis and severe fatty infiltration were common in segments with perfusion defects. In areas of redistribution, the degree of fibrosis appeared to be greater than in areas of normal perfusion; and intermuscular edema was prominent. Thus, the degree and extent of perfusion defects detected by 201Tl-SPECT were compatible with the histopathology. The presence of the redistribution phenomenon may indicate ongoing fibrosis. Initial and delayed resting 201Tl-SPECT images can predict the site and progress of myocardial degeneration in patients with DMD. (author)

  6. Determination of [{sup 201}Tl]Tl(III) in [{sup 201}Tl]TlCl solutions using HPLC

    Akhlaghi, M. [Nuclear Medicine Group, Agriculture, Medicine and Industrial Research School (AMIRS), Nuclear Science and Technology Research Institute, Moazzen Blvd., Rajaeeshahr, P.O. Box 31485-498, Karaj (Iran, Islamic Republic of)], E-mail: makhlaghi@nrcam.org; Kamalidehghan, M.; Jalilian, A.R.; Shadanpoor, N. [Nuclear Medicine Group, Agriculture, Medicine and Industrial Research School (AMIRS), Nuclear Science and Technology Research Institute, Moazzen Blvd., Rajaeeshahr, P.O. Box 31485-498, Karaj (Iran, Islamic Republic of)

    2008-04-15

    A high-performance liquid chromatography technique has been presented to measure the [{sup 201}Tl]TlCl{sub 3} impurity in [{sup 201}Tl]TlCl radiopharmaceutical for precise determination of radiochemical purity. Diethylene tetraamine pentaacetic acid (DTPA) has been used for complete complexation of [{sup 201}Tl]Tl(III). [{sup 201}Tl]Tl(III)-DTPA was analyzed in the presence of [{sup 201}Tl]Tl(I) using a cation exchange HPLC column.

  7. The interpolated projection data estimation method improves the image quality of myocardial perfusion SPECT with a short acquisition time

    The interpolated projection data estimation processing (IPDE) method increases the amount of projection data by interpolation of the projection data. We examined the usefulness of the IPDE method for 201Tl myocardial perfusion imaging (MPI) single photon emission computed tomography (SPECT) with a short acquisition time. Forty patients with suspected ischemic heart disease underwent stress 201Tl-MPI SPECT. Both stress and delayed images were acquired with 4 cycles of 360 deg continuous rotation with a 90-direction setting for 14 min. The projection data used for reconstruction were all cycle data (Tl-90-14 min), 2 cycles of data (Tl-90-7 min), and 2 cycles of data processed using the IPDE method (Tl-180IPDE-7 min). This study compared the detection of the perfusion defect by the uptake score and the image quality of 201Tl-MPI SPECT using the normalized mean square error (NMSE). The uptake score of Tl-180IPDE-7 min was significantly more concordant with Tl-90-14 min in comparison to the Tl-90-7 min (p201Tl-MPI SPECT than for the stress 201Tl-MPI SPECT (p201Tl-MPI SPECT for a short acquisition time. Furthermore, the IPDE method is a simple software program that does not require any expensive equipment or use advanced algorithms. These results suggest that the IPDE method may be useful as an adjunctive method for shortening the acquisition time of 201Tl-MPI SPECT. (author)

  8. Efficacy of iodine-123-15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid single photon emission computed tomography imaging in detecting myocardial ischemia in children with Kawasaki disease

    To evaluate its efficacy in detecting myocardial ischemia in children, iodine-123-labeled 15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP) myocardial single photon emission computed tomography (SPECT) imaging was performed in 16 pediatric patients with Kawasaki disease (KD, 11 male, 5 female; mean age and range: 13 years 8 months and 8 years 11 months to 17 years 7 months). Five children with chest pain and no cardiac disease were studied as controls (2 male, 3 female; mean age and range: 13 years 4 months and 9 years 4 months to 17 years 11 months). Selective coronary angiography was also performed in the 16 patients to evaluate the location of coronary stenosis and coronary aneurysms. The SPECT images were expressed as polar maps (Bull's eye maps) and the 'defect' area was defined as where the uptake of BMIPP was less than the standardized BMIPP images of the 5 control children. In the 16 patients, 33 segments had coronary aneurysms and 10 (10/33: 30.3%) had significant coronary stenosis on selective coronary angiography. Nine of the 10 (90%) segments with significant coronary stenosis showed a defect on the BMIPP image whereas only 6 of the 23 (26.1%) segments without coronary stenosis showed a defect on BMIPP imaging. The sensitivity of BMIPP SPECT imaging for detection of coronary stenosis was 90% (9/10) and its specificity was 73.9% (17/23), whereas the sensitivity of 201Tl SPECT imaging was 80% (8/10) and its specificity was 60% (14/23). There was no significant difference between the BMIPP and 201Tl SPECT images in either the sensitivity or specificity for the detection of coronary stenosis. In the present series, only one case had discordant BMIPP uptake (BMIPP uptake201Tl uptake) in which there was a large coronary aneurysm and re-canalization after complete obstruction at segment 1 of the right coronary artery. This discordant BMIPP uptake reflects the possibility of ischemic but viable myocardium after re-canalization of a large aneurysm in KD

  9. Myocardial stunning in hypertrophic cardiomyopathy: recovery predicted by single photon emission computed tomographic thallium-201 scintigraphy

    A young woman with hypertrophic cardiomyopathy confirmed by echocardiography and cardiac catheterization presented with chest pain and features of a large left ventricular aneurysm. The initial diagnosis was myocardial ischemia with either an evolving or an ancient myocardial infarction. Subsequently, verapamil therapy was associated with complete resolution of the extensive left ventricular wall motion abnormalities, normalization of left ventricular ejection fraction and a minimal myocardial infarction. Normal thallium uptake on single photon emission computed tomographic scintigraphy early in the hospital course predicted myocardial viability in the region of the aneurysm. Thus, orally administered verapamil may reverse spontaneous extensive myocardial ischemia in hypertrophic cardiomyopathy and possibly limit the extent of myocardial infarction in such circumstances

  10. Thallium-201 single photon emission computed tomography (SPECT) in patients with Duchenne's progressive muscular dystrophy. A histopathologic correlation study

    Nishimura, Toru; Yanagisawa, Atsuo; Sakata, Konomi; Shimoyama, Katsuya; Yoshino, Hideaki; Ishikawa, Kyozo [Kyorin Univ., Mitaka, Tokyo (Japan). School of Medicine; Sakata, Hitomi; Ishihara, Tadayuki

    2001-02-01

    The pathomorphologic mechanism responsible for abnormal perfusion imaging during thallium-201 myocardial single photon emission computed tomography ({sup 201}Tl-SPECT) in patients with Duchenne's progressive muscular dystrophy (DMD) was investigated. Hearts from 7 patients with DMD were evaluated histopathologically at autopsy and the results correlated with findings on initial and delayed resting {sup 201}Tl-SPECT images. The location of segments with perfusion defects correlated with the histopathologically abnormal segments in the hearts. Both the extent and degree of myocardial fibrosis were severe, especially in the posterolateral segment of the left ventricle. Severe transmural fibrosis and severe fatty infiltration were common in segments with perfusion defects. In areas of redistribution, the degree of fibrosis appeared to be greater than in areas of normal perfusion; and intermuscular edema was prominent. Thus, the degree and extent of perfusion defects detected by {sup 201}Tl-SPECT were compatible with the histopathology. The presence of the redistribution phenomenon may indicate ongoing fibrosis. Initial and delayed resting {sup 201}Tl-SPECT images can predict the site and progress of myocardial degeneration in patients with DMD. (author)

  11. Exercise myocardial perfusion scintigraphy is useful for evaluating myocardial ischemia even in the elderly

    Pharmacologic stress testing is recommended to elderly patients as a valuable alternative to exercise testing. We examined whether exercise testing is as useful for evaluating myocardial ischemia in the elderly as in the young. The consecutive 1,508 patients who underwent exercise 201Tl single-photon emission computed tomography (SPECT) were divided into six age groups: 6-29 years (n=56), 30-44 (n=143), 45-54 (n=311), 55-64 (n=498), 65-74 (n=402), and 75-88 (n=98). Both heart rate and rate-pressure product at peak exercise were significantly lower in patients aged 75-88 than in the other five groups. The frequency of ischemic ST depression was higher in patients aged 75-88 than in those aged 6-74, although the difference was not significant. Moreover, the frequency of 201Tl transient defect was significantly higher in patients aged 75-88 than in those aged 6-74. On the other hand, the sensitivity of ischemic ST depression for 201Tl transient defect was similar among the six groups, but the specificity was significantly lower in patients aged 75-88 than in those aged 6-74. In conclusion, exercise 201Tl SPECT is useful for evaluating myocardial ischemia even in the elderly, but exercise electrocardiography has limitations such as lower specificity in the elderly than 201Tl SPECT. (author)

  12. Evaluation of the ischemic myocardium in acute coronary syndromes using 123I-MIBG and 201TlCl SPECT imaging

    Images from myocardial I-123-meta-iodobenzylguanidine (MIBG) single photon emission computed tomography (SPECT) and Tl-201 SPECT were reviewed in 20 patients with acute coronary syndromes, including 6 with unstable angina and 7 with non-transmural myocardial infarction. Myocardial SPECT imaging was undertaken 90 min after iv injection of I-123 MIBG, followed by myocardial perfusion SPECT imaging 15 min after iv injection of 201TlCl. One week later, coronary arteriography was performed. Of 7 patients with non-transmural myocardial infarction, 3 were not recognized as having hypoperfusion or defect on Tl-201 images, but were found to have defects in culprit vessels on I-123 MIBG images. In 3 of 6 patients with unstable angina, I-123 MIBG imaging clearly visualized defects in culprit vessels, although there were no abnormal findings in serum creatinine kinase or Tl-201 myocardial imaging. Thus I-123 MIBG myocardial imaging was found to visualize ischemic zones, not detected by the other imaging methods, especially in non-transmural myocardial infarction and unstable angina. (N.K.)

  13. Detection of the viable myocardium. A perfusion scintigraphic study, before and after coronary bypass surgery in myocardial infarction patients

    Chalela Willliam A.

    1999-01-01

    Full Text Available OBJECTIVE: To compare single-photon-emission computed tomography (SPECT imaging scans using 201Tl and 99mTc-MIBI in detection of viable myocardium, in regions compromised by infarction. METHODS: Thirty-two (59.3±9.8 years old and 87% male myocardial infarction patients were studied. All had Q waves on the ECG and left ventricle ejection fraction of <50%. They underwent coronary and left ventricle angiographies and SPECT before (including 201Tl reinjection and after coronary artery bypass surgery (CABG. Improvement in perfusion observed after surgery was considered the gold standard for myocardial viability. RESULTS: Among 102 studied regions of the heart, there were 40 (39.2% areas of transient perfusion defects in the conventional protocol with 201Tl and 52 (51.0% after reinjection. Therefore, 12/62 (19.4% more viable regions were identified by reinjection. Using 99mTc-MIBI, only 14 (13.7% regions with transient defects were identified, all of which were seen also in 201Tl protocols. After surgery, 49 of a total of 93 regions analyzed (52.7% were viable. Sensitivity, specificity, accuracy, positive and negative prediction values were, respectively, 201Tl SPECT scans - 65.3%, 90.9%, 77.4%, 88.9% and 70.2%, reinjection protocol with 201Tl scans - 81.6%, 81.8%, 81.7%, 83.3% and 80.0%; 99mTc-MIBI SPECT scans - 20.4%, 90.9%, 53.8%, 71.4% and 50.6%. Logistic regression demonstrated that the reinjection protocol with 201Tl was the best predictor of viability (P<0.001. CONCLUSION: Our data suggest the election of 201Tl for viability studies, especially when using the reinjection protocol.

  14. Gated single photon emission computer tomography for the detection of silent myocardial ischemia

    Background: Asymptomatic patients with severe coronary atherosclerosis may have a normal resting electrocardiogram and stress test. Aim: To assess the yield of Gated Single Photon Emission Computer Tomography (SPECT) for the screening of silent myocardial ischemia in type 2 diabetic patients. Material and methods: Electrocardiogram, stress test and gated-SPECT were performed on 102 type 2 diabetic patients aged 60 ± 8 years without cardiovascular symptoms. All subjects were also subjected to a coronary angiography, whose results were used as gold standard. Results: Gated-SPECT showed myocardial ischemia on 26.5% of studied patients. The sensibility, specificity, accuracy, positive predictive value and negative predictive value were 92.3%, 96%, 95%, 88.8%, 97.3%, respectively. In four and six patients ischemia was detected on resting electrocardiogram and stress test, respectively. Eighty percent of patients with doubtful resting electrocardiogram results and 70% with a doubtful stress test had a silent myocardial ischemia detected by gated-SPECT. There was a good agreement between the results of gated-SPECT and coronary angiography (k =0.873). Conclusions: Gated-SPECT was an useful tool for the screening of silent myocardial ischemia

  15. Clinical usefulness of 201Tl SPECT in diagnosing nasopharyngeal tumor

    201Tl SPECT was performed on 54 patients suspected of nasopharyngeal tumor using a three-head rotating gamma camera and its clinical usefulness was evaluated. 201Tl accumulations were shown in 53 of the 54 patients (50 nasopharyngeal carcinoma, 1 malignant melanoma and 2 lymphoid hyperplasia) before treatment. In 48 of 50 patients with nasopharyngeal carcinoma, the effectiveness for treatment response could be assessed after treatment. 201Tl SPECT was concordant with MRI and CT in 26 patients (15 complete response (CR), 11 partial response (PR)), whereas it was discordant in 22 patients who showed CR in 201Tl SPECT but PR in MRI and CT. Follow-up MRI and 201Tl SPECT studies of 16 of these 22 patients from 6 to 33 months (mean 13 months) after treatment revealed that the tumor gradually decreased and finally vanished. Recurrent and metastatic lesions occurred in 8 patients from 9 to 69 months (mean 24 months) after treatment, and 201Tl SPECT could detect all 10 lesions in 8 patients. From the results obtained, it was concluded that 201Tl SPECT is very useful in the initial evaluation, in the assessment of treatment response and in detecting recurrent and metastatic lesions of nasopharyngeal tumor. (author)

  16. Gated single-photon emission tomography imaging protocol to evaluate myocardial stunning after exercise

    This study was designed to apply ECG-gating to stress myocardial perfusion single-photon emission tomography (SPET) for the evaluation of myocardial stunning after exercise. Technetium-99m sestamibi was selected as the perfusion agent and a rest/exercise 1-day protocol was employed. Fourteen patients without coronary stenosis and 33 patients with coronary stenosis were enrolled in the study. We carried out three data acquisitions with ECG-gating: a 15-min data acquisition starting 30 min after the rest injection (AC1), a 5-min acquisition starting 5 min after the stress injection (AC2) and a 15-min acquisition starting 20 min after the stress injection (AC3). Calculation of left ventricular ejection fraction (LVEF) values was performed by means of automatic determination of the endocardial surface for all gating intervals in the cardiac cycle. Measured global EF values in 14 patients without coronary stenosis were 52.3%±7.6% (AC1), 60.6%±8.9% (AC2) and 55.6%±5.6% (AC3), and those in 11 patients with severe ischaemia were 53.6%±8.0% (AC1), 45.6%±12.1% (AC2) and 49.7%±10.7%. The magnitude of the depression of post-stress LVEF relative to the rest LVEF correlated with the severity of ischaemia (r=0.594, P=0.002), and segments manifesting post-stress functional depression were associated with ischaemic segments showing reversible perfusion defects. Stress myocardial perfusion SPET with ECG-gating is a feasible method for the evaluation of myocardial stunning as well as exercise-induced ischaemia. (orig.)

  17. Standardization and decay scheme of sup 201 Tl

    Coursey, B.M.; Hoppes, D.D.; Hirschfeld, A.T. (National Inst. of Standards and Technology, Gaithersburg, MD (USA)); Judge, S.M.; Woods, D.H.; Woods, M.J. (National Physical Lab., Teddington (UK)); Funck, E.; Schrader, H. (Physikalisch-Technische Bundesanstalt, Braunschweig (Germany, F.R.)); Tuck, A.G. (Amersham International Ltd. (UK))

    1990-01-01

    An intercomparison exercise was conducted among three national standards laboratories and a commercial supplier to determine the degree of agreement between directly determined values of the activity concentration of a solution of {sup 201}Tl. The {gamma}-ray emission probabilities of {sup 201}Tl were also determined, providing an emission probability for the 167.4 keV {gamma} ray of 0.1000{plus minus}0.0006. (author).

  18. Analysis of coronary hemodynamics in exercise by 201Tl scintigraphy

    From our observation that initial distribution of 201Tl in tissue is mainly dependent on blood flow distribution, we designed the method to obtain the rates of change of coronary blood flow and coronary vascular resistance and applied it to the analysis of coronary hemodynamics in patients with ischemic heart disease during submaximal exercise. We measured the rates of change of cardiac output (Δ CO) and myocardial blood flow distribution (Δ Fract) in two occasions by the sequential two injections of Tl, and obtained the rate of change of coronary blood flow (Δ Flow) from Δ CO and Δ Fract. Using the rate of change of mean blood pressure, we calculated also the rate of change of coronary vascular resistance (Δ CVR). The initial components of histograms of the right ventricle by the first and second injections of Tl were fitted into gamma function curve. S1 and S2 were the areas bounded by the curve and baseline of the first and second injections, and then the cardiac output ratio was estimated by R x S1/S2, where R was the dose ratio measured by another camera system. The five min count rates on the myocardium by the first (H1) and second (H2) injections of Tl were calculated five min after the injection. H2 was approximately H1 x R in the same condition of Tl injection but H2 was not equal to H1 x R, when the Tl injection was done in the different loading condition. Therefore the rate of change of myocardial blood flow distribution was calculated as Δ Fract = (H1 x R - H2)/H2. With submaximal exercise the increases in Δ CO, Δ Fract and Δ Flow were smaller in patients with ischemic heart disease (IHD) than those in control subjects. In the patients with IHD, there was response of lesser degree in Δ Flow under increased myocardial oxygen demand, suggesting low coronary reserve in this condition. (author)

  19. Incidentally detected large diaphragmatic hernia in Tl-201 myocardial perfusion scintigraphy; no substantial effect on the study results

    Özdemir, Semra; Erselcan, Taner; Hasbek, Zekiye; Tandoğan, İzzet; GÜMÜŞ, CESUR

    2011-01-01

    AbstractA case of diaphragmatic hernia, detected incidentally by Thallium 201 (Tl-201) myocardial perfusion scintigraphy (MPS), was presented. We recognized a large photon deficient area in the right lung and middle mediastinum regions, also attenuating cardiac activity in the first 10 projections during the evaluation of stress and rest single-photon emission computed tomography (SPECT) projections of the subject. Computed tomography (CT) examination of the mass revealed a diaphragmatic hern...

  20. Thallium-201 single-photon emission tomography in the treatment follow-up of nasopharyngeal carcinoma

    In order to assess the usefulness of thallium-201 single-photon emission tomography (SPET) in the treatment follow-up of nasopharyngeal carcinoma (NPC), a total of 75 201Tl SPET studies were performed in 18 patients with histologically proven NPC. The findings were compared with those of magnetic resonance imaging (MRI) before and after therapy. Four patients received radiotherapy alone while the other 14 received concurrent chemo-radiotherapy. Treatment response was classified as complete (CR) or partial (PR) based on the findings of MRI and 201Tl SPET. Intense 201Tl uptake by the tumour was seen in all 18 patients before treatment. After treatment, MRI showed seven CRs and 11 PRs, whereas 201Tl SPET showed 13 CRs and five PRs. In 12 patients, the results of 201Tl SPET were in agreement with those of MRI. In six patients MRI showed PR but 201Tl showed CR. Follow-up (mean 10.6 months) MRI and 201Tl SPET studies of these six patients revealed that tumour gradually decreased and finally vanished in three patients. This preliminary study indicates that 201Tl SPET has potential in the assessment of early response to treatment of patients with NPC when compared with MRI. (orig.)

  1. 201Tl and 99Tcm-HMPAO SPECT imaging in brain lesions

    Eighty-five patients with three different types of brain lesions were included in the study. Twenty-five patients with malignant astrocytoma, either post-operatively (15 cases) or with recurrent tumour versus gliosis (10 cases), were studied using 201Tl SPECT (single photon emission computed tomography). Calculation of early delayed uptake and the retention index showed high early late uptake with low retention index in high grade astrocytoma versus a low mean value of early and delayed uptake with a high retention index in low grade glioma. Also, recurrent cases showed remarkable differences in early and delayed 201Tl uptake (P 201Tl SPECT (100%) versus 80% using computed tomography (CT) scanning. Furthermore, 30 patients with interictal epileptic fits were evaluated with 99Tcm-HMPAO (hexamethylpropylene amine oxime), electroencephalogram (EEG) and CT, with sensitivities of 80, 73.3 and 20%, respectively. The third group of 30 patients with different onset of cerebrovascular stroke was evaluated with 99Tcm-HMPAO. They showed larger lesions in both the acute phase (8 patients) and the subacute phase (12 patients) compared with CT scanning. Also, crossed cerebellar diaschiasis was seen in 50% of each group and 'luxury' perfusion in 30% of the subacute phase. Additional lesions with signs of cerebral atrophy in 75% of acute 50% of subacute phases were noted. A similar finding was noted for 99Tcm-HMPAO and CT scanning in ten patients in a chronic phase with no evidence of other lesions, cerebellar diaschiasis, or signs of cerebral atrophy. (author). 13 refs, 3 figs

  2. Phantom evaluation of simultaneous thallium-201/technetium-99m acquisition in single-photon emission tomography

    This study investigated downscatter effects in cardiac single-photon emission tomographic studies with simultaneous thallium-201/technetium-99m acquisition, and evaluated a previously proposed subtraction technique for downscatter compensation. Ten studies were carried out with different defect sizes and locations and varying activity distributions using four energy windows: 70±10% keV, 140±10% keV, 100±10% KeV, and 103±16% keV. The subtraction technique used the 100- or 103-keV data to remove scattered 99mTc counts from the 70-keV data. The size and contrast of infarcts in the dual-isotope 70-keV image were artificially decreased compared to those in the 140-keV image, caused by scattered 99mTc counts that were comparable to the primary 201Tl counts in the 70-keV window. The subtraction technique produced larger defects and more heterogeneous activity in the myocardial wall in dual-isotope 70-keV images compared to the corresponding 201Tl-only images. These artifacts were caused by the markedly different spatial distributions of scattered 99mTc counts in the 100-keV (or 103-keV) window as compared with the 70-keV window. It is concluded that scattered 99mTc photons may cause overestimation of ischemia and myocardial viability in simultaneous dual-isotope patient studies. The proposed subtraction technique was inaccurate and produced image artifacts. Adequate downscatter compensation methods must be developed before applying simultaneous 201Tl/99mTc acquisition in clinical practice. (orig.). With 6 figs., 3 tabs

  3. Sympathetic reinnervation following heart transplantation: a double-tracer study with 123I-MIBG and 201Tl

    Sympathetic reinnervation was evaluated in 15 patients 2-69 months after heart transplantation using a double-tracer technique with 123I-MIBG and 201Tl. Since MIBG is accumulated in the same manner as norepinephrine it may serve as a tracer of the integrity and function of the sympathetic nervous system. 201Tl was used for landmarking. Planar anterior imaging was performed 15 min and 4 h after i.v. injection of 220 MBq 123I-MIBG and 37 MBq 201Tl. Image quantitation was based on the ratio of myocardial to mediastinal MIBG-uptake. Cardiac regions of interest were defined according to the 201Tl uptake. There was no evidence of sympathetic reinnervation in 8 patients 2-34 months after transplantation. Increased MIBG-uptake could be observed in the anterior basal region in 6 long-term cardiac transplants (37-69 months). One patient with a 59-month-old transplanted heart did not reinnervate. Increased MIBG-uptake in the anterior basal region indicating partial sympathetic reinnervation could be shown in 40% of the investigated patients with an average organ age of 51 months. (orig.)

  4. Detection of myocardial infarction with dual energy CT myocardial iodine maps and perfusion myocardial single photon emission computed tomography scintigraphy: an experimental study in canine

    Objective: To investigate the feasibility and accuracy of dual energy CT myocardial iodine maps in detecting acute myocardial infarction in canine model. Methods: Myocardial ischemia model was made by ligaturing left anterior descending coronary arteries (LAD) after thoracotomy in six dogs, while another 3 dogs undergoing thoracotomy not ligaturing LAD as control group. Before and three hours after operation, dual-source CT (DSCT) was performed, followed by resting 99Tcm-MIBI single photon emission computed tomography myocardial perfusion imaging. Then, dogs were sacrificed, and the hearts were removed, triphenyketrazolium chloride staining and conventional HE staining were performed. CT number of non-ischemic and ischemic regions were measured and analyzed. The wall of the left ventricle in the short axis was divided into 17 segments, the segments of myocardial perfusion defect in DSCT myocardial iodine maps, SPECT, and pathology were determined. Student t test was used to analyze the difference of CT number between infarcted and non-infarcted myocardium. Kappa test was used for the accuracy of DSCT myocardial iodine maps and SPECT in detecting myocardial ischemia according to the pathological results. Results: No abnormal regions were detected using DSCT myocardial iodine maps in preoperative control and infarction group. After thoracotomy, partial sparse or defective perfusion was consistently noted in six dogs' apical anterior and partition wall in both DSCT myocardial iodine maps and SPECT. In the infarcted group, the attenuation of infarction region (34.75±16.66) HU was significantly decreased compared with preoperative measurements (123.18±15.38 ) HU (t=10.526, P<0.01); decreased perfusion in the infarcted region was also noted in the DSCT myocardial iodine maps and SPECT. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of DSCT myocardial iodine maps and SPECT were 85.0% (34/40), 84.1% (95/113), 65.4% (34

  5. Attenuation correction in pulmonary and myocardial single photon emission computed tomography

    Almquist, H

    2000-01-01

    The objective was to develop and validate methods for single photon emission computed tomography, SPECT, allowing quantitative physiologic and diagnostic studies of lung and heart. A method for correction of variable attenuation in SPECT, based on transmission measurements before administration of an isotope to the subject, was developed and evaluated. A protocol based upon geometrically well defined phantoms was developed. In a mosaic pattern phantom count rates were corrected from 39-43% to 101-110% of reference. In healthy subjects non-gravitational pulmonary perfusion gradients observed without attenuation correctionwere artefacts caused by attenuation. Pulmonary density in centre of right lung, obtained from the transmission measurement, was 0.28 {+-} 0.03 g/ml in normal subjects. Mean density was lower in large lungs compared to smaller ones. We also showed that regional ventilation/perfusion ratios could be measured with SPECT, using the readily available tracer {sup 133}Xe. Because of the low energy of {sup 133}Xe this relies heavily upon attenuation correction. A commercially available system for attenuation correction with simultaneous emission and transmission, considered to improve myocardial SPECT, performed erroneously. This could lead to clinical misjudgement. We considered that manufacturer-independent pre-clinical tests are required. In a test of two other commercial systems, based on different principles, an adapted variant of our initial protocol was proven useful. Only one of the systems provided correct emission count rates independently on phantom configuration. Errors in the other system were related to inadequate compensation of the influence of emission activity on the transmission study.

  6. Attenuation correction in pulmonary and myocardial single photon emission computed tomography

    The objective was to develop and validate methods for single photon emission computed tomography, SPECT, allowing quantitative physiologic and diagnostic studies of lung and heart. A method for correction of variable attenuation in SPECT, based on transmission measurements before administration of an isotope to the subject, was developed and evaluated. A protocol based upon geometrically well defined phantoms was developed. In a mosaic pattern phantom count rates were corrected from 39-43% to 101-110% of reference. In healthy subjects non-gravitational pulmonary perfusion gradients observed without attenuation correction were artefacts caused by attenuation. Pulmonary density in centre of right lung, obtained from the transmission measurement, was 0.28 ± 0.03 g/ml in normal subjects. Mean density was lower in large lungs compared to smaller ones. We also showed that regional ventilation/perfusion ratios could be measured with SPECT, using the readily available tracer 133Xe. Because of the low energy of 133Xe this relies heavily upon attenuation correction. A commercially available system for attenuation correction with simultaneous emission and transmission, considered to improve myocardial SPECT, performed erroneously. This could lead to clinical misjudgement. We considered that manufacturer-independent pre-clinical tests are required. In a test of two other commercial systems, based on different principles, an adapted variant of our initial protocol was proven useful. Only one of the systems provided correct emission count rates independently on phantom configuration. Errors in the other system were related to inadequate compensation of the influence of emission activity on the transmission study

  7. Evaluating image denoising methods in myocardial perfusion single photon emission computed tomography (SPECT) imaging

    The statistical nature of single photon emission computed tomography (SPECT) imaging, due to the Poisson noise effect, results in the degradation of image quality, especially in the case of lesions of low signal-to-noise ratio (SNR). A variety of well-established single-scale denoising methods applied on projection raw images have been incorporated in SPECT imaging applications, while multi-scale denoising methods with promising performance have been proposed. In this paper, a comparative evaluation study is performed between a multi-scale platelet denoising method and the well-established Butterworth filter applied as a pre- and post-processing step on images reconstructed without and/or with attenuation correction. Quantitative evaluation was carried out employing (i) a cardiac phantom containing two different size cold defects, utilized in two experiments conducted to simulate conditions without and with photon attenuation from myocardial surrounding tissue and (ii) a pilot-verified clinical dataset of 15 patients with ischemic defects. Image noise, defect contrast, SNR and defect contrast-to-noise ratio (CNR) metrics were computed for both phantom and patient defects. In addition, an observer preference study was carried out for the clinical dataset, based on rankings from two nuclear medicine clinicians. Without photon attenuation conditions, denoising by platelet and Butterworth post-processing methods outperformed Butterworth pre-processing for large size defects, while for small size defects, as well as with photon attenuation conditions, all methods have demonstrated similar denoising performance. Under both attenuation conditions, the platelet method showed improved performance with respect to defect contrast, SNR and defect CNR in the case of images reconstructed without attenuation correction, however not statistically significant (p > 0.05). Quantitative as well as preference results obtained from clinical data showed similar performance of the

  8. Study of 201Tl uptake by bone and bone marrow on 201Tl scintigraphy

    Thallium-201 (Tl-201) uptake in the bone and bone marrow was examined in a total of 93 patients with various diseases. Sternal uptake of Tl-201 was observed when patients had bone marrow abnormality especially associated with hematopoietic disease. It was associated with proliferation of immature cells and of various types of bone marrow cells, especially erythroblastic and plasma cells. Whole-body Tl-201 scanning showed a high uptake (82%) in the sternum, chest, lumbar vertebrae, and pelvis. Thallium-201 was definitively taken up by the sternum in polycythemia (5/41), hemolytic anemia (2/2), iron deficiency anemia (2/2), and multiple myeloma (2/5). For leukemia, Tl-201 uptake was slight or negative. Thallium-201 scanning proved useful in visualizing bone marrow abnormality, although careful interpretation of bone and bone marrow uptake is required. (Namekawa, K)

  9. Venous uptake of 201Tl as thallous chloride

    Thallium-201, injected as thallous chloride, has been found to adhere to or be taken up by the vein into which it is injected, permitting images to be obtained of human veins up to 4 h following injection. A digoxin-insensitive rat vein model also retained 201Tl but for shorter periods of time. 201Tl uptake is independent of the solution into which it is introduced, whether 5% dextrose or 0.9% sodium chloride. This technique permits multiple delayed views of normal veins to be obtained but is of uncertain value in the evaluation of thrombophlebitis of the calf because of rather poor resolution and high cost. (author)

  10. Serial evaluation of 123I-BMIPP/201Tl myocardial single-proton emission computed tomography after coronary stent implantation in ischemic heart disease. Association with recovery of left ventricular function

    Coronary stent implantation is often used to treat ischemic heart disease. However, few studies have evaluated myocardial viability with single-proton emission computed tomography (SPECT) and both thallium and β-methyl-iodophenyl-pentadecanoic acid (BMIPP) after coronary stent implantation. Forty patients (30 men and 10 women, 64.8±9.3 years old) who had undergone successful stent implantation were enrolled. Twenty-two patients had angina pectoris (AP) and 18 patients had acute myocardial infarction (AMI). We performed BMIPP and thallium SPECT immediately after coronary stent implantation and at 3 months follow-up and compared the results with left ventriculograms. Myocardial SPECT images were divided into 17 segments, after which defect scores (1 to 5) were assigned to each segment and summed to obtain a total defect score (TDS). Left ventriculograms were divided into 9 segments, each of which was given a wall motion score (WMS; 1 to 5). In patients with either AP or AMI, the TDS of BMIPP and thallium SPECT images were significantly better at 3 months follow-up than immediately after stent implantation. In patients with AP, improvements in TDS on BMIPP and thallium SPECT were not associated with improvements in WMS. In patients with AMI, improvements in TDS on BMIPP SPECT were correlated with improvements in WMS (r=0.69, p<0.01) and in left ventricular ejection fraction (r=0.70, p<0.01), and improvements in TDS on thallium SPECT were correlated with improvements in WMS (r=0.64, p<0.01) but were not associated with improvements in left ventricular ejection fraction. In conclusion, a decrease in BMIPP myocardial uptake in patients with AP suggests previous episodes of severe myocardial ischemia. Improvements in BMIPP uptake in patients with AMI may indicate recovery of left ventricular function. Coronary stent implantation for severe myocardial ischemia contributes to improvements in myocardial viability. (author)

  11. Role of myocardial perfusion single photon emission computed tomography in pediatric cardiology practice

    Diagnostic and prognostic power of myocardial perfusion imaging in patients with coronary artery disease has been demonstrated with planar imaging which was further improvised with addition of gated SPECT and newer Technetium labeled myocardial perfusion tracers like SestaMIBI, Tetrofosmin. Myocardial perfusion abnormalities at rest and after stress are considered to be the best predictors of cardiac event–free survival in adults with ischemic heart disease. This article highlights various myocardial perfusion imaging (MPI) radiopharmaceuticals, exercise procedures, pharmacological stress protocols, indications for MPI and myocardial perfusion patterns in children with some of the common congenital and acquired heart diseases

  12. Role of myocardial perfusion single photon emission computed tomography in pediatric cardiology practice

    Sundaram P

    2009-01-01

    Full Text Available Diagnostic and prognostic power of myocardial perfusion imaging in patients with coronary artery disease has been demonstrated with planar imaging which was further improvised with addition of gated SPECT and newer Technetium labeled myocardial perfusion tracers like SestaMIBI, Tetrofosmin. Myocardial perfusion abnormalities at rest and after stress are considered to be the best predictors of cardiac event-free survival in adults with ischemic heart disease. This article highlights various myocardial perfusion imaging (MPIradiopharmaceuticals, exercise procedures, pharmacological stress protocols, indications for MPI and myocardial perfusion patterns in children with some of the common congenital and acquired heart diseases.

  13. Comparison of positron tomography and scintigraphy with 201Tl for delineation of the myocardium

    Recent advances in nuclear medicine instrumentation have led to the development of improved positron-imaging systems which exceed in performance the earlier systems which were limited mainly by low count rate capability. This has led to renewed interest in positron imaging in general, primarily because such devices offer better resolution and higher sensitivity than conventional, mechanically collimated gamma cameras, as well as tomographic capability which may provide additional and more accurate information for the clinician. Furthermore, the unique capabilities of positrons for use in reconstructive imaging are beginning to be exploited. In the present report, results are presented from a preliminary study in which longitudinal tomographic myocardial images, produced with 81Rb as the positron-emitting label using the double camera coincidence system are compared with conventional myocardial images obtained with 201Tl and a gamma camera

  14. Single photon radionuclide computed tomography with Tomogscanner II, (1)

    The single photon radionuclide computed tomography (RCT) was examined in 214 patients with the Tomogscanner-II. The RCT of brain was superior to the conventional brain scan, especially in the detection of lesions at the base of brain or the postoperated condition. The blood pool RCT of brain depicted an arterio-venous malformation and a giant aneurysma at the base of brain. The RCT of cisternography was useful to understand the anatomical relationship of the activity. The RCT of cerebral blood perfusion was possible with a method of continuous infusion of sup(81m)Kr into an internal carotid artery. In the body study, the reconstructed image of the Tomogscanner was excellent. The area of myocardial infarction showed clear defect in the horse-shaped myocardial section image after injection of 4 mCi of 201TlCl. The RCT of liver was available to detect defects and evaluated the activity and size of spleen. The RCT of kidney, lung or bone also showed good image, respectively. The Tomogscanner-II gave very good images in clinical examination of body as well as brain. (author)

  15. Technetium-99m sestamibi single-photon emission tomography detects subclinical myocardial perfusion abnormalities in patients with systemic lupus erythematosus

    Schillaci, O. [Nuclear Medicine, University of l`Aquila (Italy); Lagana, B.; Gentile, R.; Tubani, L.; Baratta, L. [Department of Clinical Medicine, University ``La Sapienza``, Rome (Italy); Danieli, R.; Scopinaro, F. [Section of Nuclear Medicine, Department of Experimental Medicine and Pathology, University ``La Sapienza``, Rome (Italy)

    1999-07-01

    In patients with systemic lupus erythematosus, involvement of the cardiovascular system is the third leading cause of death. However, although autopsy studies have demonstrated a high incidence of abnormalities in both the myocardium and coronary vessels, clinical manifestations have been reported in only a small percentage of cases. The aim of this study was to evaluate myocardial perfusion in asymptomatic lupus patients using technetium-99m sestamibi single-photon emission tomography (SPET). Twenty-eight patients without overt cardiac involvement and risk factors were studied with {sup 99m}Tc-sestamibi SPET at rest and after dipyridamole infusion. Perfusion abnormalities were detected in 18 cases: six had persistent defects, three had reversible defects, seven had both persistent and reversible defects, and two showed rest defects which normalized on dipyridamole images (``reverse redistribution pattern``). Coronary angiography was performed in eight patients with positive {sup 99m}Tc-sestamibi SPET, and showed normal epicardial vessels in all the cases. These results indicate that {sup 99m}Tc-sestamibi SPET reveals a high prevalence (18 out of 28 patients in this study, i.e. 64%) of myocardial perfusion abnormalities in asymptomatic lupus patients, probably due to the primary immunological damage of this autoimmune disease. In conclusion, rest/dipyridamole {sup 99m}Tc-sestamibi SPET can be a useful non-invasive method to identify subclinical myocardial involvement in systemic lupus erythematosus, and patients potentially at risk of later cardiac events. (orig.) With 2 figs., 2 tabs., 21 refs.

  16. Physiological basis for stress-induced myocardial stunning as assessed by gated single-photon emission computed tomography

    Postischemic myocardial stunning as assessed by gated single-photon emission computed tomography (SPECT) has been criticized for being a perfusion-associated artifact caused by false endocardial tracking. We hypothesized that if severe perfusion defects all cause false wall motion abnormality, they should be observed regardless of the underlying mechanisms of perfusion abnormality. We evaluated 132 patients with stress-induced perfusion defects of moderate severity or more after exercise (n=84) or adenosine triphosphate disodium (ATP) stress (n=48) were evaluated using gated 99mTc-sestamibi SPECT. Summed stress and difference scores were similar in the 2 groups. However, the overall incidence of post-stress stunning was 54% in the exercise group, but only 19% in the ATP group (p<0.0001). Furthermore, based on the severity of coronary artery stenosis in 43 patients with 1-vessel disease, the prevalence of post-stress stunning was 77% in patients with ≥99% coronary stenosis, 67% in those with 90% stenosis, and 29% in those with 75% stenosis after exercise stress, whereas it was 57% in those with ≥99% stenosis, 17% in those with 90% stenosis, and 0% in those with 75% stenosis after ATP stress (p=0.003). The predominant mechanism of post-stress wall motion abnormality observed by gated SPECT was thought to be severe myocardial ischemia, but not a perfusion-associated artifact. Thus, this scintigraphic finding was regarded as actual myocardial stunning. (author)

  17. Technetium-99m sestamibi single-photon emission tomography detects subclinical myocardial perfusion abnormalities in patients with systemic lupus erythematosus

    In patients with systemic lupus erythematosus, involvement of the cardiovascular system is the third leading cause of death. However, although autopsy studies have demonstrated a high incidence of abnormalities in both the myocardium and coronary vessels, clinical manifestations have been reported in only a small percentage of cases. The aim of this study was to evaluate myocardial perfusion in asymptomatic lupus patients using technetium-99m sestamibi single-photon emission tomography (SPET). Twenty-eight patients without overt cardiac involvement and risk factors were studied with 99mTc-sestamibi SPET at rest and after dipyridamole infusion. Perfusion abnormalities were detected in 18 cases: six had persistent defects, three had reversible defects, seven had both persistent and reversible defects, and two showed rest defects which normalized on dipyridamole images (''reverse redistribution pattern''). Coronary angiography was performed in eight patients with positive 99mTc-sestamibi SPET, and showed normal epicardial vessels in all the cases. These results indicate that 99mTc-sestamibi SPET reveals a high prevalence (18 out of 28 patients in this study, i.e. 64%) of myocardial perfusion abnormalities in asymptomatic lupus patients, probably due to the primary immunological damage of this autoimmune disease. In conclusion, rest/dipyridamole 99mTc-sestamibi SPET can be a useful non-invasive method to identify subclinical myocardial involvement in systemic lupus erythematosus, and patients potentially at risk of later cardiac events. (orig.)

  18. Technetium-99m sestamibi and tetrofosmin myocardial single-photon emission tomography: can we use the same reference data base?

    The aim of this study was to compare technetium-99m labelled tetrofosmin and sestamibi myocardial perfusion single-photon emission tomography (SPET) with one common sestamibi reference file for bull's eye imaging, with quantitation of the extent and severity of perfusion defects. Twenty patients suspected or known to have coronary artery disease participated in the study. Patients first underwent routine sestamibi myocardial SPET over 2 days, receiving doses of 400-600 MBq at stress and 600-800 MBq at rest. Then within the same week a 1-day tetrofosmin myocardial SPET study was performed, with a dose of 300 MBq at stress, followed 2.5 h later by a dose of 750 MBq at rest. Bull's eye images were generated for visual evaluation. Black-out defects according to the Cequal software analysis were only recorded if they comprised more than 10 pixels in men and 20 in women. According to the Cequal program, extent score and severity scores were expressed as number of pixels and deviations below reference limits. Five patients had normal myocardial SPET imaging with both radiotracers, while 15 had reversible, irreversible or partially reversible defects. The concordance of the results was high. The only two significant differences were that one patient had a reversible defect which appeared to be located in different myocardial regions (LAD vs RCA), and another patient had a defect that was partially reversible with sestamibi but irreversible with tetrofosmin. The results showed very high correlation coefficients for the extent and severity scores (linear correlation coefficient values of 0.99 and 0.94, respectively). In conclusion, it appears that changing between sestamibi and tetrofosmin has little influence on the interpretation of bull's eye images from the data file of a common reference population using one of the tracers. (orig.). With 3 figs., 3 tabs

  19. Reverse redistribution phenomenon on rest 99mTc-tetrofosmin myocardial single photon emission computed tomography involves impaired left ventricular contraction in patients with acute myocardial infarction

    The purpose of this study was to investigate the clinical significance of the reverse redistribution (RR) phenomenon on technetium-99m (99mTc)-tetrofosmin myocardial single photon emission computed tomography (SPECT) performed at rest. Twenty-five patients underwent myocardial SPECT 3 weeks after the onset of acute myocardial infarction. Myocardial images were acquired at 40 min (early) and 4 h (delayed) after the injection of 740 MBq of 99mTc-tetrofosmin. The regional myocardial uptake of the tracer in 26 segments of the left ventricular (LV) wall was visually scored from 0 (no activity) to 3 (normal activity), and then the RR was defined as a decrease of more than 1 point in the activity score on the delayed image compared with that on the early image. Regions with an activity score of 3 on both the early and delayed images were defined as normal, and those with a score of 0 or 1 on the early image were considered to have a fixed defect. The regional myocardial 99mTc-tetrofosmin uptake and washout rate were also quantitatively assessed in each region. In addition, exercise stress electrocardiograph-gated SPECT with 99mTc-tetrofosmin was performed within 1 week of the rest study, and the percent count increase (%CI) during myocardial contraction in each corresponding region was studied. RR was observed in 18 of the 25 patients. The regional washout rate of 99mTc-tetrofosmin was significantly higher in the RR regions (45.0±3.8%) than in either the normal regions (36.4±4.1%, p99mTc-tetrofosmin SPECT have severely impaired LV wall contraction after exercise. (author)

  20. Iodine-123-labelled fatty acids for myocardial single-photon emission tomography: current status and future perspectives

    Renewed interest in the clinical use of iodine-123-labelled fatty acids is currently primarily focused on the use of iodine-123-labelled 15-(p-iodophenyl)pentadecanoic acid (IPPA) and ''modified'' fatty acid analogues such as 15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP) which show delayed myocardial clearance, thus permitting single-photon emission tomographic imaging. Interest in the use of BMIPP and similar agents results from the differences which have often been observed in various types of heart disease between regional myocardial uptake patterns of [123I]BMIPP and flow tracer distribution. Although the physiological basis is not completely understood, differences between regional fatty acid and flow tracer distribution may reflect alterations in important parameters of metabolism which can be useful for patient management or therapy planning. These tracers may also represent unique metabolic probes for correlation of energy substrate metabolism with regional myocardial viability. The two agents currently most widely used clinically are 123I-labelled IPPA and BMIPP. While [123I]IPPA is commercially available as a radiopharmaceutical in Europe (Cygne) and Canada (Nordion), multicenter trials are in progress in the United States as a prelude to approval for broad use. [123I]BMIPP was recently introduced as Cardiodine for commercial distribution in Japan (Nihon Medi-Physics, Inc.). [123I]BMIPP is also being used in clinical studies on an institutional approval basis at several institutions in Europe and the United States. In this review, the development of a variety of radioiodinated fatty acids is discussed. The results of clinical trials with [123I]IPPA and [123I]BMIPP are discussed in detail, as are the future prospects for fatty acid imaging. (orig.)

  1. Quantification of myocardial infarct size by thallium-201 single-photon emission computed tomography: experimental validation in the dog

    To evaluate the potential advantages of thallium-201 (201T1) single-photon emission computerized tomography (SPECT) to assess myocardial infarct size in the experimental animal, six normal dogs and 14 dogs with 6 to 8 hr closed-chest coronary occlusion (eight left anterior descending and six left circumflex) were studied. Ten minutes after intravenous administration of 2 mCi of 201T1, 30 projections were obtained over 1800. The dogs were killed and their hearts sliced and stained by triphenyl tetrazolium chloride (TTC). Pathologic infarct size was calculated for each slice and for the entire left ventricular myocardium as percent weight. Tomograms were quantified by automatically generating maximum-count circumferential profiles, which were compared with normal limit profiles derived from the six normal dogs. Tomographic infarct size was defined as the percentage of circumferential points falling below normal for each tomogram. SPECT and TTC infarct size on 71 slices correlated highly (mean +/- SD 27.9 +/- 23.4% and 26.7 +/- 25.3%, respectively; r = .93, p less than .001, SEE = 9.4%). To determine SPECT infarct size as percent total left ventricular myocardial weight, infarct sizes from each slice were added to one another after each was multiplied by a coefficient that reflected the contribution of that slice to the total left ventricular weight. SPECT and TTC infarct size for the entire left ventricle correlated closely (mean +/- SD 20.5 +/- 7.6% and 19.3 +/- 8.3%, respectively; r = .86, p less than .001, SEE = 4.5%). It is concluded that 201T1 SPECT is a valid method for the noninvasive assessment of experimental myocardial infarct size

  2. A mechanism for myocardial uptake of /sup 201/Tl

    Although the kinetics of Tl have been studied extensively the mechanisms governing its intracellular distribution in myocardium are not fully understood. One possibility is that Tl distributes within the interstitial and intracellular spaces according to the electrochemical gradients established by the cell membrane potential (ΔPSI). If so, the equilibrium concentrations C/sub I/ (intracellular) and C/sub O/ (interstitial) will obey the second law of thermodynamics as expressed by the Nernst Equations. To test this hypothesis the authors used a preparation of beating fetal mouse hearts in an organ culture medium. The measured concentration ratio (mouse heat to medium), R, was measured as a function of time and was fit to the model R=0.323[1+(K/sub I//K/sub O/)(1-EXP(-K/sub O/t)], where K/sub I/ and K/sub O/ are the inward and outward rate constants for transport across the cell membrane. At equilibrium, conservation of tracer mass ensures that C/sub I//C/sub O/=0.323 K/sub I//K/sub O/, where 0.323 is the ratio of interstitial to intracellular volume. In the control state the model estimate of the equilibrium membrane potential was -87 mV; whereas, for graded tissue injury the magnitude of the membrane potential decreased in proportion to the severity of injury. These data, obtained without the confounding effect of blood flow, show that intracellular Tl uptake in the fetal mouse heart can be interpreted in terms of membrane potential. The results of this work can in principle be extended to the use of radiolabeled molecules and ECT for in vivo measurement of regional membrane potential

  3. Stress Tl-201 myocardial single photon emission computed tomography in diagnosing ischemic heart disease

    Using a dual-head rotating gamma camera system, stress SPECT and conventional planar imaging were performed for 138 patients while they were examined by symptom-limited graded bicycle ergometer exercise. All patients underwent selective coronary arteriography and left ventriculography, and 93 had myocardial infarction (MI), 30 had effort angina (EA) and 15 were normal (control). Sensitivities for detecting IHD (SPECT: planar = 96 %: 89 %, p < 0.01), individual coronary arterial lesions (left anterior descending artery = LAD, 84 %: 68 %, p < 0.005; left circumflex artery = LCX, 60 %: 47 % NS; right coronary artery = RCA, 88 %: 69 %, p < 0.01), multivessel disease (= LAD + LCX and/or RCA, 53 %: 31 %, p < 0.025), and three vessel disease (60 %: 13 %, p < 0.005) were significantly higher by SPECT than by planar imaging. In addition, detection of ventricular aneurysms by SPECT was possible with a reasonably high sensitivity (94 %) and specificity (84 %). Signs of aneurysm included 1) an extensive anterior permanent defect, 2) a large left ventricular cavity, and 3) widening of the angle composed by the septal and lateral walls toward the apex in transaxial images. Sensitivity for detecting IHD was significantly lower in patients without MI (i.e., EA) than in patients with MI (MI: EA = 100 %: 83 %, p < 0.005). Sensitivity for detecting individual coronary arterial lesions was lower in the absence than in the presence of MI (LAD; 77 %: 87 %, LCX; 38 %: 68 %, RCA; 71 %: 90 %, respectively), with multivessel disease than with single vessel disease, and with mild than with severe grade of stenosis. Sensitivity for detecting multivessel disease was lower in patients without MI than in those with MI (31 %: 61 %, respectively), and in anterior MI than in posteroinferior MI, or both MIs (36 %: 69 %: 100%, respectively). (J.P.N.)

  4. Clinical usefulness of {sup 201}Tl SPECT in diagnosing nasopharyngeal tumor

    Togawa, Takashi; Yui, Nobuharu; Hatano, Kazuo; Takeuchi, Yousuke; Hayasaki, Katsutake [Chiba Cancer Center (Japan); Omura, Ken [Tokyo Medical and Dental Univ. (Japan). Graduate School

    2003-03-01

    {sup 201}Tl SPECT was performed on 54 patients suspected of nasopharyngeal tumor using a three-head rotating gamma camera and its clinical usefulness was evaluated. {sup 201}Tl accumulations were shown in 53 of the 54 patients (50 nasopharyngeal carcinoma, 1 malignant melanoma and 2 lymphoid hyperplasia) before treatment. In 48 of 50 patients with nasopharyngeal carcinoma, the effectiveness for treatment response could be assessed after treatment. {sup 201}Tl SPECT was concordant with MRI and CT in 26 patients (15 complete response (CR), 11 partial response (PR)), whereas it was discordant in 22 patients who showed CR in {sup 201}Tl SPECT but PR in MRI and CT. Follow-up MRI and {sup 201}Tl SPECT studies of 16 of these 22 patients from 6 to 33 months (mean 13 months) after treatment revealed that the tumor gradually decreased and finally vanished. Recurrent and metastatic lesions occurred in 8 patients from 9 to 69 months (mean 24 months) after treatment, and {sup 201}Tl SPECT could detect all 10 lesions in 8 patients. From the results obtained, it was concluded that {sup 201}Tl SPECT is very useful in the initial evaluation, in the assessment of treatment response and in detecting recurrent and metastatic lesions of nasopharyngeal tumor. (author)

  5. ASSESSMENT OF MYOCARDIAL VIABILITY WITH CONTRASTENHANCED MAGNETIC RESONANCE IMAGING AND COMPARISON WITH SINGLE-PHOTON EMISSION COMPUTED TOMOGRAPHY

    Yi-ning Wang; Zheng-yu Jin; Zhu-hua Zhang; Ling-yan Kong; Li-bo Chen; Lu Zhou; Hong-yi Sun; Heng Zhang; Qi Miao

    2006-01-01

    Objective To compare contrast-enhanced magnetic resonance imaging (ceMRI) with nuclear metabolic imaging for the assessment of myocardial viability in patients with chronic ischemic heart disease.Methods Twenty patients with suspected chronic ischemic heart disease underwent ceMRI and technetium-99m sestamibi single-photon emission computed tomography (SPECT).Patients with positive SPECT results also underwent 18F-fluorodeoxyglucose (FDG) SPECT.In a 17-segment model,the segmental extent of hyperenhancement (SEH) by ceMRI was compared with segmental FDG and sestamibi uptake by SPECT.Correlation between the extent of hyperenhancement by ceMRI and left ventricular function was analyzed.Results Seven patients got negative results both in ceMRI and technetium-99m sestamibi SPECT.The rest 13 patients with positive results then underwent 18F-FDG SPECT.In 221 segments of 13 patients,SEH was (2.1±8.2)%,(25.0±13.7)%,and (57.7±23.6)% in segments with normal metabolism/perfusion,metabolism/perfusion mismatch,and matched defects,respectively,and there were significant differences between either two of them (all P<0.05).By receiver operating characteristic curve analysis,the area under the curve was 0.95 for the differentiation between viable and non-viable segments.At the cutoff value of 34%,SEH optimally differentiated viable from non-viable segments defined by SPECT.Using this threshold,the sensitivity and specificity of ceMRI to detect non-viable myocardium as defined by SPECT were 92% and 93%,respectively.Hyperenhancement size by ceMRI was correlated negatively with the left ventricular ejection fraction (r=-0.90,P<0.01) and positively with left ventricular volumes (r=0.62 for end-diastolic volume,r=0.75 for end-systolic volume,both P<0.05).Conclusion CeMRI allows assessment of myocardial viability with a high accuracy in patients with chronic ischemic heart disease.

  6. Postoperative myocardial infarction documented by technetium pyrophosphate scan using single-photon emission computed tomography: Significance of intraoperative myocardial ischemia and hemodynamic control

    Cheng, D.C.; Chung, F.; Burns, R.J.; Houston, P.L.; Feindel, C.M. (Toronto Hospital, Ontario (Canada))

    1989-12-01

    The aim of this prospective study was to document postoperative myocardial infarction (PMI) by technetium pyrophosphate scan using single-photon emission computed tomography (TcPPi-SPECT) in 28 patients undergoing elective coronary bypass grafting (CABG). The relationships of intraoperative electrocardiographic myocardial ischemia, hemodynamic responses, and pharmacological requirements to this incidence of PMI were correlated. Radionuclide cardioangiography and TcPPi-SPECT were performed 24 h preoperatively and 48 h postoperatively. A standard high-dose fentanyl anesthetic protocol was used. Twenty-five percent of elective CABG patients were complicated with PMI, as documented by TcPPi-SPECT with an infarcted mass of 38.0 +/- 5.5 g. No significant difference in demographic, preoperative right and left ventricular function, number of coronary vessels grafted, or aortic cross-clamp time was observed between the PMI and non-PMI groups. The distribution of patients using preoperative beta-adrenergic blocking drugs or calcium channel blocking drugs was found to have no correlation with the outcome of PMI. As well, no significant differences in hemodynamic changes or pharmacological requirements were observed in the PMI and non-PMI groups during prebypass or postbypass periods, indicating careful intraoperative control of hemodynamic indices did not prevent the outcome of PMI in these patients. However, the incidence of prebypass ischemia was 39.3% and significantly correlated with the outcome of positive TcPPi-SPECT, denoting a 3.9-fold increased risk of developing PMI. Prebypass ischemic changes in leads II and V5 were shown to correlate with increased CPK-MB release (P less than 0.05) and tends to occur more frequently with lateral myocardial infarction.

  7. Postoperative myocardial infarction documented by technetium pyrophosphate scan using single-photon emission computed tomography: Significance of intraoperative myocardial ischemia and hemodynamic control

    The aim of this prospective study was to document postoperative myocardial infarction (PMI) by technetium pyrophosphate scan using single-photon emission computed tomography (TcPPi-SPECT) in 28 patients undergoing elective coronary bypass grafting (CABG). The relationships of intraoperative electrocardiographic myocardial ischemia, hemodynamic responses, and pharmacological requirements to this incidence of PMI were correlated. Radionuclide cardioangiography and TcPPi-SPECT were performed 24 h preoperatively and 48 h postoperatively. A standard high-dose fentanyl anesthetic protocol was used. Twenty-five percent of elective CABG patients were complicated with PMI, as documented by TcPPi-SPECT with an infarcted mass of 38.0 +/- 5.5 g. No significant difference in demographic, preoperative right and left ventricular function, number of coronary vessels grafted, or aortic cross-clamp time was observed between the PMI and non-PMI groups. The distribution of patients using preoperative beta-adrenergic blocking drugs or calcium channel blocking drugs was found to have no correlation with the outcome of PMI. As well, no significant differences in hemodynamic changes or pharmacological requirements were observed in the PMI and non-PMI groups during prebypass or postbypass periods, indicating careful intraoperative control of hemodynamic indices did not prevent the outcome of PMI in these patients. However, the incidence of prebypass ischemia was 39.3% and significantly correlated with the outcome of positive TcPPi-SPECT, denoting a 3.9-fold increased risk of developing PMI. Prebypass ischemic changes in leads II and V5 were shown to correlate with increased CPK-MB release (P less than 0.05) and tends to occur more frequently with lateral myocardial infarction

  8. Non-invasive evaluation of myocardial reperfusion by transthoracic Doppler echocardiography and single-photon emission computed tomography in patients with anterior acute myocardial infarction

    Celutkiene Jelena

    2011-05-01

    Full Text Available Abstract Background The study was designed to evaluate whether the preserved coronary flow reserve (CFR 72 hours after reperfused acute myocardial infarction (AMI is associated with less microvascular dysfunction and is predictive of left ventricular (LV functional recovery and the final infarct size at follow-up. Methods In our study, CFR was assessed by transthoracic Doppler echocardiography (TDE in 44 patients after the successful percutaneous coronary intervention during the acute AMI phase. CFR was correlated with contractile reserve assessed by low-dose dobutamine echocardiography and with the total perfusion defect measured by single-photon emission computed tomography 72 hours after reperfusion and at 5 months follow-up. The ROC analysis was performed to determine test sensitivity and specificity based on CFR. Categorical data were compared by an χ2 analysis, continuous variables were analysed with the independent Student's t test. In order to analyse correlation between CFR and the parameters of LV function and perfusion, the Pearson correlation analysis was conducted. The linear regression analysis was used to assess the relationship between CFR and myocardial contractility as well as the final infarct size. Results We estimated the CFR cut-off value of 1.75 as providing the maximal accuracy to distinguish between patients with preserved and impaired CFR during the acute AMI phase (sensitivity 91.7%, specificity 75%. Wall motion score index was better in the subgroup with preserved CFR as compared to the subgroup with reduced CFR: 1.74 (0.29 vs. 1.89 (0.17 (p Conclusion The early measurement of CFR by TDE can be of high value for the assessment of successful reperfusion in AMI and can be used to predict LV functional recovery, myocardial viability and the final infarct size.

  9. Extraction chromatography in isotope production: application in the production of 67Ga and 201Tl

    Extraction chromatography was applied to the production of the radioisotopes 67Ga and 201Tl. 67Ga was produced by irradiation of natural zinc target with 24 MeV protons in a cyclotron. The separation of 67Ga was carried out by extraction chromatography from 6N HCL. 201Tl was produced in a similar way using lead as a precursor, and it was extracted using 4N HNO3 or HCL. (U.K.)

  10. Comparison of post-exercise and post-vasodilator stress myocardial stunning as assessed by electrocardiogram-gated single-photon emission computed tomography

    Exercise gated single-photon emission computed tomography (SPECT) using technetium-99m (99mTc)-sestamibi evaluates both myocardial perfusion during stress and wall motion >30 min after the stress, which has the potential to assess not only exercise-induced myocardial ischemia but also the development of myocardial stunning. To evaluate the incidence of post-stress myocardial stunning, as well as comparing the effects of different stress methods on the development of stunning, 179 consecutive patients with known or suspected coronary artery disease (CAD) underwent 99mTc-sestamibi SPECT with either exercise (n=135) or adenosine triphosphate disodium (ATP) (n=44). Electrocardiogram-gated SPECT images were acquired >30 min after the stress and again 4 h later, and perfusion and wall motion were evaluated. Post-stress myocardial stunning occurred in 24 patients (13%): 22 after exercise and 2 after ATP stress. The magnitude of the transient wall motion abnormality after exercise was greater in patients with severe ischemia, compared with those with mild-to-moderate ischemia (p99mTc-sestamibi gated SPECT, myocardial stunning is frequently observed after exercise and correlates with the severity of myocardial ischemia, but this does not occur with ATP, which is regarded as a specific marker for severe CAD. (author)

  11. Evaluation of acquisition time for calculating retention index of 201Tl lung tumor SPECT

    In 201Tl SPECT imaging for lung tumor, retention index has been known to be useful for the quantitative evaluation of 201Tl retention in the tumor. The value of retention index varies depending on the imaging time after 201Tl injection. We evaluated a variation of the retention index as a function of time after 201Tl injection, and determined optimum imaging timing for the calculation of the 201Tl retention index. A dynamic SPECT acquisition was performed over 40 min with 5 minutes for a SPECT image set. Four frames were summed to make a SPECT image set, and five SPECT acquisition sets were generated. Delayed image was acquired 2 hours after injection. Target to Non target (T/N) count ratios between one of the early image and the delayed image were calculated. The retention index was defined as (delayed T/N-early T/N) divided by early T/N. We found that 201Tl activity of normal lung tissue decreased slowly with time and the T/N ratio increased. Therefore, the retention index was significantly influenced by the starting time of acquisition. The retention index calculated by a data set with a starting time at 15 to 20 min after administration was stable. Fixed acquisition protocol should be performed for reliable calculation of the retention index. (author)

  12. Studies on the diagnosis of uterine body cancer using 201Tl-chloride

    201Tl scintigraphy was performed in 18 patients with cancer of uterine body, and the results were compared with histopathological findings. With six patients, 201Tl distribution in the pelvic cavity was registered in the minicomputer, and the time activity curve was plotted. Analysis of 201Tl distribution using ROI revealed that the radioactivity in the uterus was approximately 1.47 times as high as that in background. In the removed uterus, the radioactivity in the cancer was calculated to be approximately 1.9 times as high as that in the myometrium. In all 13 patients with Stage Ib or higher cancer, obvious activity in the uterus coinciding with the lesion was obtained shortly after the intravenous administration of 201Tl-Cl. Though accumulation of activity in the uterus was obtained in three of five patients with Stage Ia cancer, it was interpreted as false-positive, because myoma or adenomyosis was present in addition to cancer in these three patients, and such a complication seemed responsible for the positive result. The sensitivity, specificity and accuracy of 201Tl scintigraphy in diagnosing cancer of the uterine body were 86.7, 0 and 72.2%, respectively. These results suggest that 201Tl scintigraphy is a promising diagnostic aid for cancer of the uterine body. (author)

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

    Tedeschi, E. [Dipartimento di Diagnostica per Immagini, Centro CNR per la Medicina Nucleare, Napoli (Italy); Soricelli, A. [Dipartimento di Diagnostica per Immagini, Centro CNR per la Medicina Nucleare, Napoli (Italy); Brunetti, A. [Dipartimento di Diagnostica per Immagini, Centro CNR per la Medicina Nucleare, Napoli (Italy); Romano, M. [Dipartimento di Diagnostica per Immagini, Centro CNR per la Medicina Nucleare, Napoli (Italy); Bucciero, A. [Istituto di Neurochirurgia, Universita `Federico II`, Napoli (Italy); Iaconetta, G. [Istituto di Neurochirurgia, Universita `Federico II`, Napoli (Italy); Alfieri, A. [Istituto di Neurochirurgia, Universita `Federico II`, Napoli (Italy); Postiglione, A. [Dipartimento di Clinica Medica, Universita `Federico II`, Napoli (Italy); Salvatore, M. [Dipartimento di Diagnostica per Immagini, Centro CNR per la Medicina Nucleare, Napoli (Italy)

    1996-11-01

    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 ({sup 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 {sup 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 {sup 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 {sup 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 <0.01). Conversely, in the delayed scan, most lesions showed high tracer concentration, and the two groups could not be distinguished. In addition, three recurrent meningiomas displayed the same imaging behaviour as the malignant group, i.e. had similar {sup 201}Tl concentration values at 2-4 and at 14-16 min. Our findings suggest that the comparative assessment of intratumoral {sup 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.

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

    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 (201Tl). On a brain-dedicated SPET scanner, a rapid acquisition protocol with early, short scans was started simultaneously with the intravenous administration of 111 MBq 201Tl, 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 201Tl 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 201Tl 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 201Tl concentration values at 2-4 and at 14-16 min. Our findings suggest that the comparative assessment of intratumoral 201Tl 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

  15. Dual myocardial single photon emission computed tomography (SPECT) using thallium-201 and I-123-β-methyl-i-pentadecanoic acid in patients with Duchenne's progressive muscular dystrophy

    Dual single photon emission computed tomography (SPECT) was performed in 31 patients with Duchenne's progressive muscular dystrophy (DMD) using 123I-β-methyl pentadecanoic acid (BMIPP) for myocardial fatty acid metabolism and 201thallium (Tl)-chloride for myocardial perfusion. The left ventricle was divided into 9 segments, and accumulation of the radiotracers was assessed visually for each segment to calculate defect score for each tracer. There was some degree of decrease in myocardial accumulation of both tracers in all DMD patients. Reduced accumulation was most common at the apex (BMIPP: 67%, Tl: 63%), followed by the posterior wall, lateral wall, and anterior wall. On the other hand, reduced accumulation was less common at the septum. BMIPP showed a higher accumulation than Tl in all segments but the septum. When BMIPP defect score was larger than Tl defect score, BMIPP defect score tended to increase during 4 years follow-up (p Tl defect score revealed a slight fibrosis or normal myocardium. It can be concluded that the dual SPECT myocardial scintigraphy using BMIPP and Tl provides accurate information about disease progression of the heart in patients with DMD by detecting abnormalities of the myocardial metabolism of each substance, thereby enabling the assessment of left ventricular function. (author)

  16. Correlation of MIB-1 staining index and 201Tl-SPECT retention index in preoperative evaluation of malignancy of brain tumors

    MIB-1 staining provides a useful index of the malignancy of brain tumors. However, because of the difficulty of evaluating malignancy based on the preoperative imaging findings, we investigated the correlation between the 201Tl-single photon emission computed tomography (SPECT) retention index (RI) and MIB-1 staining index (MIB-1 SI) to determine the usefulness of RI for preoperative evaluation of the malignancy of brain tumors. The subjects of this study were 47 patients who underwent tumor removal surgery at our hospital in 2006 and 2007. The tumors consisted of 16 intraaxial tumors (all gliomas: 9 glioblastomas, 2 anaplastic astrocytomas, 2 anaplastic oligoastrocytomas, 1 oligodendroglioma, and 2 ependymomas), 8 other malignant brain tumors, and 23 extraaxial tumors (10 meningiomas, 7 pituitary adenomas, and 6 schwannomas). The mean RI and mean MIB-1 SI of the intraaxial tumors were 0.628% and 32.0%, respectively, and after MIB-1 SI was converted to the natural logarithm (log MIB-1 SI), Pearson's coefficient for the correlation between them was significant (r=0.752, P201Tl-SPECT RI values were useful as an index of malignancy. RI values may also be useful for evaluating apparently benign extraaxial tumors for possible malignancy. (author)

  17. Evaluating the sensitivity and specificity of 201Tl SPECT in intracranial tumoral pathology

    The aim of this study was to evaluate the sensitivity of SPECT with 201Tl in detecting the cerebral tumors. A hundred and forty nine explorations were carried out (107 SPECT in patients clinically suspected and/or cerebral tumor radiography, 42 SPECT in patients treated for cerebral tumor to evaluate the persistence of the tumoral tissue immediately post-operation, or the presence of a tumoral recurrence). The SPECTs were achieved 15 minutes after the IV injection of 185 MBq of 201Tl with a double head Elscint Helix HR camera with fan collimators. The reconstructions were obtained by retro-projection with a Metz 3.13 filter. As the brain normally do not capture 201Tl, any fixation of 201Tl was considered an positive examination. The final diagnosis was based either on the histology (n = 41) or on clinical evolution (n = 149). The pathologies recorded were: 33 glial tumors, 32 metastases (51 lesions), 14 meningiomas, 1 hypophyseal adenoma, 1 cranio-pharyngogioma, 1 malign lymphoma, 1 gr.4 neurinomas, 1 arachnoid cyst, 34 AVCs, 24 normal, 2 complete surgical extirpations, and 5 necroses after treatment. In our population the sensitivity of SPECT with 201Tl for the diagnosis of intracranial tumors was calculated to be 91.5% and the specificity, 98.5%. We have met a false positive (recent hemorrhagic AVC) and 7 false negatives (4 metastases of which 3 were under 1 cm and another largely necrotic, 3 patients presenting residual tumoral tissue immediately post-operation, presently in recurrence). These excellent results prove the utility of SPECT with 201Tl both for positive diagnosis of cerebral tumors and for evaluation of these tumors after treatment

  18. Experimental investigation of 201TlCl-scintigraphy in evaluating therapeutic effect of hyperthermia

    We investigated the usefulness of 201Tl-scintigraphy in the evaluation of therapeutic effect of hyperthermia. Satoh's experimental lung cancer tumors implanted in the right thighs of donryu rats were treated with hyperthermia using water bath. Tumors were heated at 44degC or 46degC for 15 min. 201Tl-scintigraphy was obtained before, immediately after and 24 hrs after treatment. Counts ratio of the tumor of the normal muscle (T/N ratio) was measured by gamma camera. We examined blood flow of the tumor, and relative tumor growth rate, and performed autoradiogram and histopathological examination of the tumor after 201Tl-scintigraphy. Immediately after hyperthermia, T/N ratio and blood flow of the tumor significantly decreased (p201TlCl in the tumor decreased diffusely. Histopathological finding showed congestion, thrombosis, and swelling of endothelial cells. These results suggest that the decrease in T/N ratio may be caused by the vascular damage due to hyperthermia. The T/N ratio recovered 24 hrs after hyperthermia but was still lower than that for the control. Autoradiogram showed that 201TlCl greatly accumulated in viable tumor tissue but was hardly seen in the necrotic tumor tissue. These results suggest that the decrease in T/N ratio may be caused by increase of necrotic areas. The T/N ratio 24 hrs after hyperthermia correlated (r=0.83) with relative tumor growth rate on 7th day after hyperthermia and, therefore, can be used as an indicator of relative tumor growth rate. 201Tl-scintigraphy can be useful for prediction of therapeutic effect of hyperthermia. (author)

  19. 201Tl brain SPECT in differentiating central nervous system lymphoma from toxoplasmosis in AIDS patients

    In AIDS patients, toxoplasmosis and lymphoma are the leading causes of CNS mass lesions. It is important to make the correct diagnosis expeditiously, since the two diseases require markedly different treatments and have different prognoses. In general, CT and MR imaging have failed to provide specific distinguishing characteristics to differentiate CNS lymphoma from toxoplasmosis, and it is difficult to differentiate these entities clinically. We performed 201Tl brain SPECT in order to differentiate two diseases. Counts ratio of a lesion to the normal brain (L/N ratio) was elevated in patients of lymphoma compared in patients of toxoplasmosis. 201Tl brain SPECT is useful to differentiate CNS lymphoma from toxoplasmosis. (author)

  20. 201Tl-SPECT, 1H-MRS, and MIB-1 labeling index of central neurocytomas: three case reports

    Background: The proliferative activity and metabolic features of three central neurocytomas were investigated using the findings of thallium-201 single photon emission computed tomography (201Tl-SPECT) and proton magnetic resonance spectroscopy (1H-MRS), and the MIB-1 labeling index (MIB-1 LI). Method: The early and delayed 201TI indices were calculated as the ratio of tumor to normal brain tissue uptake by 201TI-SPECT. In vivo single-voxel 1H-MRS was performed with echo time of 272 msec to evaluate the metabolites including choline (Cho), N-acetyl aspartate (NAA) and creatine/phosphocreatine (Cre). An external standard reference was used to semiquantitate each metabolite. MIB-1 LI was determined in the surgical specimens. Findings: The MIB-l LI was 0.5 %, 1.2 %, and 7.5 % in an atypical central neurocytoma without intraventricular extension. Significant 201TI uptake was observed on delayed images in all three central neurocytomas. 1H-MRS showed the high Cho peaks relative to the NAA and Cre peak. The signal at 3.55 ppm, which may be due to inositol or glycine, was observed in one central neurocytoma. Interpretation: Both 201TI-SPECT and 1H-MRS did not reflect the proliferative potential of central neurocytomas. (author)

  1. Quantification of left ventricular size on exercise thallium-201 single-photon emission tomography

    The purposes of this study were to determine whether quantification of the left ventricular size on exercise thallium-201 single-photon emission tomography (SPET) correlates with echocardiographic measurements, whether the quantification reflects the severity of coronary artery disease, and whether it can provide supplementary information regarding the severity of coronary artery disease. In 42 control subjects and 110 patients who underwent coronary angiography, we performed exercise 201Tl SPET and quantified six non-regional markers: Lung 201Tl uptake on an initial planar image (Lung/Heart), left ventricular width on a tomogram (Width), change in the Width from the initial to delayed tomograms (ΔWidth), count ratio of the left ventricular cavity to the myocardium (C/M), count ratio of the lung to the myocardium (L/M), and count ratio of the lung to the left ventricular cavity (L/C). In 76 patients, furthermore, the Width was compared with echocardiographic measurements. The Width correlated with echocardiographic measurements (P201Tl SPET correlated with echocardiogrpahic measurements and reflected the severity of coronary artery disease, but may be replaced with quantitation of the lung 201Tl uptake. (orig.)

  2. Comparison of flow capacities of arterial and venous grafts for coronary artery bypass grafting: evaluation with exercise thallium-201 single-photon emission tomography

    Stress thallium-201 tomography was performed to compare the flow capacities of arterial and saphenous vein grafts in patients with coronary artery bypass grafting (CABG). One hundred and seven consecutive patients (95 male and 12 female; mean age 58±9.1 years) underwent exercise-redistribution 201Tl myocardial single-photon emission tomography 4-5 weeks after CABG. When a reversible perfusion defect was present in the area covered by a patent bypass graft, the flow capacity of the graft was defined as insufficient. Of all 285 grafts, 211 were considered as complete bypass. Reversible perfusion defects were present in 29 (27%) of 108 myocardial areas supplied by patent arterial grafts but in only 5 (5%) of 103 myocardial areas supplied by patent saphenous vein grafts (P<0.0001). In the LAD area reversible defects were observed in 22 of 82 areas covered by arterial grafts, in contrast to only 1 of 29 areas covered by venous grafts (P<0.01); in the RCA area reversible defects were observed in 7 of 17 and 4 of 41 areas respectively (P<0.01). There was no difference between the native coronary artery stenosis bypassed by patent arterial and venous grafts (88%±12% vs 86%±14% respectively, P=0.27). In conclusion, flow capacities during peak myocardial demand were more frequently insufficient in arterial bypass grafts than in saphenous vein grafts. (orig.)

  3. Comparison of 180° and 360° Arc Data Acquisition to Measure Scintigraphic Parameters from Gated Single Photon Emission Computed Tomography Myocardial Perfusion Imaging: Is There Any Difference?

    Javadi, Hamid; Mahmoud-Pashazadeh, Ali; Mogharrabi, Mehdi; Iranpour, Darioush; Amini, Abdollatif; Pourbehi, Mohammadreza; Akbarzadeh, Mehdi; Nabipour, Iraj; Assadi, Majid

    2016-01-01

    Objective: The aim of the current study was to compare 180° and 360° data collection modes to measure end diastolic volume (EDV), end systolic volume (ESV) and ejection fraction (EF) values of the cardiac system by gated myocardial perfusion tomography. Methods: Thirty-three patients underwent gated myocardial perfusion tomography. Single photon emission computed tomography data of patients’ heart were acquired by 180°, 45° left posterior oblique to 45° right anterior oblique, and 360° to obtain EDV, ESV, EF and cardiac volume changes (V1, V2, V3, V4, V5, V6, V7 and V8) throughout each cardiac cycle. Results: Results of the current study indicated that there were no significant differences between 180° and 360° angular sampling in terms of measuring EDV, ESV and EF in myocardial perfusion imaging. Cardiac volume change patterns during a cardiac cycle were also similar in 360° and 180° scans. We also observed that there was no difference in EDV, ESV and EF values between the group with stress induced by exercise and the group with stress imposed by dipyridamole. Conclusion: As there is no difference between 180°and 360° cardiac scanning in terms of EDV, ESV and EF, half-orbit scan is recommended to study these cardiac system parameters because it offers more comfort to patients and a shorter scanning time.

  4. Comparison of 180° and 360° Arc Data Acquisition to Measure Scintigraphic Parameters from Gated Single Photon Emission Computed Tomography Myocardial Perfusion Imaging: Is There Any Difference?

    Hamid Javadi

    2016-02-01

    Full Text Available Objective: The aim of the current study was to compare 180° and 360° data collection modes to measure end diastolic volume (EDV, end systolic volume (ESV and ejection fraction (EF values of the cardiac system by gated myocardial perfusion tomography. Methods: Thirty-three patients underwent gated myocardial perfusion tomography. Single photon emission computed tomography data of patients’ heart were acquired by 180°, 45° left posterior oblique to 45° right anterior oblique, and 360° to obtain EDV, ESV, EF and cardiac volume changes (V1, V2, V3, V4, V5, V6, V7 and V8 throughout each cardiac cycle. Results: Results of the current study indicated that there were no significant differences between 180° and 360° angular sampling in terms of measuring EDV, ESV and EF in myocardial perfusion imaging. Cardiac volume change patterns during a cardiac cycle were also similar in 360° and 180° scans. We also observed that there was no difference in EDV, ESV and EF values between the group with stress induced by exercise and the group with stress imposed by dipyridamole. Conclusion: As there is no difference between 180°and 360° cardiac scanning in terms of EDV, ESV and EF, half-orbit scan is recommended to study these cardiac system parameters because it offers more comfort to patients and a shorter scanning time.

  5. Myocardial metabolic, hemodynamic, and electrocardiographic significance of reversible thallium-201 abnormalities in hypertrophic cardiomyopathy

    Exercise-induced abnormalities during thallium-201 scintigraphy that normalize at rest frequently occur in patients with hypertrophic cardiomyopathy. However, it is not known whether these abnormalities are indicative of myocardial ischemia. Fifty patients with hypertrophic cardiomyopathy underwent exercise 201Tl scintigraphy and, during the same week, measurement of myocardial lactate metabolism and hemodynamics during pacing stress. Thirty-seven patients (74%) had one or more 201Tl abnormalities that completely normalized after 3 hours of rest; 26 had regional myocardial 201Tl defects, and 26 had apparent left ventricular cavity dilatation with exercise, with 15 having coexistence of these abnormal findings. Of the 37 patients with reversible 201Tl abnormalities, 27 (73%) had metabolic evidence of myocardial ischemia during rapid atrial pacing compared with four of 13 patients (31%) with normal 201Tl scans (p less than 0.01). Eleven patients had apparent cavity dilatation as their only 201Tl abnormality; their mean postpacing left ventricular end-diastolic pressure was significantly higher than that of the 13 patients with normal 201Tl studies (33 +/- 5 versus 21 +/- 10 mm Hg, p less than 0.001). There was no correlation between the angiographic presence of systolic septal or epicardial coronary arterial compression and the presence or distribution of 201Tl abnormalities. Patients with ischemic ST segment responses to exercise had an 80% prevalence rate of reversible 201Tl abnormalities and a 70% prevalence rate of pacing-induced ischemia. However, 69% of patients with nonischemic ST segment responses had reversible 201Tl abnormalities, and 55% had pacing-induced ischemia. Reversible 201Tl abnormalities during exercise stress are markers of myocardial ischemia in hypertrophic cardiomyopathy and most likely identify relatively underperfused myocardium

  6. Effects of CT-based attenuation correction of rat microSPECT images on relative myocardial perfusion and quantitative tracer uptake

    Purpose: Our goal in this work was to investigate the impact of CT-based attenuation correction on measurements of rat myocardial perfusion with 99mTc and 201Tl single photon emission computed tomography (SPECT). Methods: Eight male Sprague-Dawley rats were injected with 99mTc-tetrofosmin and scanned in a small animal pinhole SPECT/CT scanner. Scans were repeated weekly over a period of 5 weeks. Eight additional rats were injected with 201Tl and also scanned following a similar protocol. The images were reconstructed with and without attenuation correction, and the relative perfusion was analyzed with the commercial cardiac analysis software. The absolute uptake of 99mTc in the heart was also quantified with and without attenuation correction. Results: For 99mTc imaging, relative segmental perfusion changed by up to +2.1%/−1.8% as a result of attenuation correction. Relative changes of +3.6%/−1.0% were observed for the 201Tl images. Interscan and inter-rat reproducibilities of relative segmental perfusion were 2.7% and 3.9%, respectively, for the uncorrected 99mTc scans, and 3.6% and 4.3%, respectively, for the 201Tl scans, and were not significantly affected by attenuation correction for either tracer. Attenuation correction also significantly increased the measured absolute uptake of tetrofosmin and significantly altered the relationship between the rat weight and tracer uptake. Conclusions: Our results show that attenuation correction has a small but statistically significant impact on the relative perfusion measurements in some segments of the heart and does not adversely affect reproducibility. Attenuation correction had a small but statistically significant impact on measured absolute tracer uptake

  7. Determination of thallium content in 201Tl processing waste by UV-spectrophotometry

    Thallium-201 is a radioisotope widely used for visualization of heart or cardiovascular diagnosis. It is generally produced by means of 203Tl(p,3n)201Pb -->201Tl reaction using enriched 203Tl (more than 95%) as target material. Since the enriched 203Tl is very expensive, the recovery of 203Tl from 201Tl-processing waste is very important. For this reason, a high accuracy and good precision method for Tl measurement is required. Having a single absorbance maximum at 214 nm which is stable up 24 hours post preparation, it is expected that Tl can be quantitatively determined by spectrophotometry in the UV region. The chemical matrices in the 201Tl-processing waste were separated by hydroxide precipitation, stipping extraction and charcoal adsorption techniques. The linearity of the absorbance standard curve is given by regression line A = 0.0013 + 0.0223C with C is concentration in mg/dm3. The regression coefficient was found to be 0.9999. Evaluation using simulated waste solutions and 201Tl-processing waste samples showed that both the accuracy and the precision, in terms of repeatability, of the measurement were high. (author)

  8. Studies on portal systemic circulation by oral administration of 201Tl enclosed enteric coated capsule

    Thallium-201 enclosed enteric coated capsule was prepared and administered orally to evaluate portal systemic circulation in 11 control subjects and 31 patients with various liver diseases by investigating scintigraphic appearance and the heart-to-liver uptake ratio (H/L ratio). In 10 patients with liver cirrhosis and one with chronic hepatitis, the results of H/L ratio were compared to those obtained by 201Tl per-rectal administration. 1. It was fundamentally confirmed that 201Tl enclosed enteric coated capsule was not broken down in the artificial gastric juice, but nearly completely melted 15 minutes after soaking in the artificial intestinal juice. 2. Clinical study was successfully completed in 36 out of 42 cases (86 %). Unsuccessful cases were found in 2 with capsule collapse in the stomach and 4 with its poor moving to the duodenum. 3. In control subjects the liver was clearly visualized and the mean value of H/L ratio was 0.32 which is lower than that of 201Tl per-rectal administration previously reported. H/L ratio in patients with chronic and acute hepatitis was nearly equal to that in control subjects. H/L ratio in patients with liver cirrhosis was slightly higher than that in control subjects, but there was no significant difference between them. In cases with esophageal varices, H/L ratio was not so high compared to that in control subjects. Out of 7 patients showing high H/L ratio more than 0.8 in 201Tl per-rectal administration, only one showed similar high ratio (1.07) in oral administration of 201Tl enclosed enteric coated capsule. In this case the shunting from superior mesenteric vein to inferior vena cava connection was confirmed. From these results, it was considered that the shunting volume of superior mesenteric vein through esophageal varices is small. 4. A possibility of a new administration of radioisotope with enteric coated capsule was emphasized. (author)

  9. Single Photon Emission Computed Tomography (SPECT)

    ... Tools & Resources Stroke More Single Photon Emission Computed Tomography (SPECT) Updated:Sep 11,2015 What is a ... Heart Attack Myocardial Perfusion Imaging (MPI) Positron Emission Tomography (PET) Radionuclide Ventriculography, Radionuclide Angiography, MUGA Scan Heart ...

  10. Effects of exercise training on myocardial fatty acid metabolism in rats with depressed cardiac function induced by transient ischemia

    The effects of exercise training on metabolic and functional recovery after myocardial transient ischemia were investigated in a rat model. Male Wistar Kyoto rats were subjected either to a 30-min left coronary artery occlusion followed by reperfusion or to a sham operation. At 4 weeks after operation, the rats were randomly assigned either to sedentary conditions or to exercise training for 6 weeks. In the ischemic rats, pinhole SPECT (single photon emission computed tomography) imaging with thallium-201 (201Tl) and 123I-(ρ-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP) showed a reduction of both myocardial perfusion and fatty acid metabolism in the risk zone of the left ventricle (LV). The LV was dilated and the ejection fraction was decreased after ischemic injury. The severity score showed a significant decrease on both 201Tl and BMIPP (201Tl, from 19.9±2.7 to 17.0±2.2, p<0.05; BMIPP, from 21.5±2.4 to 18.6±1.9, p<0.05) after exercise training in the ischemic trained rats, but did not change significantly in their sedentary counterparts. Plasma levels of free fatty acids normalized in the ischemic trained rats, but elevated in the ischemic sedentary rats (0.53±0.05 vs 0.73±0.06 mmol/L, p<0.05). Furthermore, the trained rats had a significant increase in LV stroke volume (0.25±0.02 vs 0.21±0.01 ml/beat, p<0.05) and adaptive cardiac hypertrophy. These findings demonstrate that adaptive improvements in myocardial perfusion, fatty-acid metabolism and LV function were induced by exercise training after transient ischemia. (author)

  11. Application of transmission scan-based attenuation compensation to scatter-corrected thallium-201 myocardial single-photon emission tomographic images

    A practical method for scatter and attenuation compensation was employed in thallium-201 myocardial single-photon emission tomography (SPET or ECT) with the triple-energy-window (TEW) technique and an iterative attenuation correction method by using a measured attenuation map. The map was reconstructed from technetium-99m transmission CT (TCT) data. A dual-headed SPET gamma camera system equipped with parallel-hole collimators was used for ECT/TCT data acquisition and a new type of external source named ''sheet line source'' was designed for TCT data acquisition. This sheet line source was composed of a narrow long fluoroplastic tube embedded in a rectangular acrylic board. After injection of 99mTc solution into the tube by an automatic injector, the board was attached in front of the collimator surface of one of the two detectors. After acquiring emission and transmission data separately or simultaneously, we eliminated scattered photons in the transmission and emission data with the TEW method, and reconstructed both images. Then, the effect of attenuation in the scatter-corrected ECT images was compensated with Chang's iterative method by using measured attenuation maps. Our method was validated by several phantom studies and clinical cardiac studies. The method offered improved homogeneity in distribution of myocardial activity and accurate measurements of myocardial tracer uptake. We conclude that the above correction method is feasible because a new type of 99mTc external source may not produce truncation in TCT images and is cost-effective and easy to prepare in clinical situations. (orig.)

  12. False-positive defects in technetium-99m sestamibi myocardial single-photon emission tomography in healthy athletes with left ventricular hypertrophy

    Exercise ECG and myocardial single-photon emission tomography (SPET) are fundamental in the non-invasive evaluation of patients suspected of having coronary artery disease (CAD). The purpose of the present study was to investigate the influence of physiological left ventricular hypertrophy (LVH) on myocardial sestamibi SPET in healthy young and old athletes. Eighteen young male elite athletes (ten rowers, five power/weight lifters and three triathletes) and 14 well-trained elderly rowers were studied. All underwent a bicycle test as part of a 2-day sestamibi SPET protocol. Attenuation correction was not performed. The studies were evaluated visually and quantitatively analysed by the CEqual program with its reference files and with a file from a local non-athletic age-matched population. Echocardiographic LVH was an inclusion criterion in the young athletes. Exercise ECG was normal in all subjects. In at least three of the young athletes a reversible defect was observed by visual analysis. On quantitative analysis one-third of the young athletes had ''significant'' (>10 pixels) defects compared with both the local reference base and the CEqual reference population. Nearly all defects were found in the anterior or inferior wall. The remaining subjects, including all old rowers, had normal SPET findings. Anterior and inferior wall defects are so common in healthy athletes with physiological LVH that the specificity of myocardial SPET, in contrast to exercise ECG, seems to be too low for evaluation of chest pain in this group. The mechanism of anterior and inferior defects may be related to hot spots (papillary muscles?) in the lateral wall. The specificity of SPET is maintained in athletes without LVH. (orig.)

  13. Assessment of prognostic value of semiquantitative parameters on gated single photon emission computed tomography myocardial perfusion scintigraphy in a large middle eastern population

    Coronary artery disease is the leading cause of mortality worldwide. The goal of this study is to determine the prognostic value of semiquantitative parameters of electrocardiogram-gated single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) in a large Middle Eastern (Iranian) population. This study was a prospective study including all patients referred to our center for myocardial perfusion scan. The patients were followed annually up to 24 months and their survival information was collected. From 1148 patients, 473 (41.2%) men and 675 (58.8%) women, 40.6% had normal MPI, 13.3% near normal and 46.1% abnormal MPI. After follow-up of 929 patients, 97.4% of patients were alive, and 2.6% succumbed to cardiac deaths. Abnormal ejection fraction was related with cardiac events (P = 0.001), but neither transient ischemic dilation (TID) (P = 0.09) nor lung/heart ratio (P = 0.92) showed such relationship. Association between summed difference score (SDS) and soft cardiac events (P < 0.001) was significant. Summed motion score (SMS) and summed thickening score (STS) showed a significant relation with hard cardiac events, including myocardial infarction and cardiac death (P < 0.001 and P = 0.001, respectively). Totally, risk of all cardiac events was significantly higher in abnormal MPI group than normal group (P < 0.001, 0.02, and 0.025, respectively). No significant relationship was found between TID and total cardiac events (P = 0.478). Semiquantitative variables derived from gated SPECT MPI have independent prognostic value. Rate of total cardiac events is higher in patients with higher summed stress score and SDS. Total and hard cardiac events are higher in upper scores of functional parameters (SMS and STS). Total cardiac events are higher in patients with lower left ventricular ejection fraction

  14. Prognostic value of post-ischemic stunning as assessed by gated myocardial perfusion single-photon emission computed tomography. A subanalysis of the J-ACCESS study

    To determine the prognostic value of post-ischemic stunning, the Japanese assessment of cardiac event and survival study by quantitative gated myocardial single-photon emission computed tomography (SPECT) (J-ACCESS) study was reevaluated. Of the 4,031 patients of the J-ACCESS, the present study evaluated 1,089 who completed gated SPECT both after stress and at rest. To assess post-ischemic stunning, the following measurements (left ventricular volumes after stress minus volumes at rest) were made: Δend-systolic volume (ΔESV), Δend-diastolic volume (ΔEDV) and Δejection fraction (ΔEF). Myocardial stunning defined either as ΔESV ≥5 ml, ΔEDV ≥5 ml or ΔEF ≤-5% was observed in 21%, 22%, or 26%, respectively. During a 3-year follow-up, 101 cardiac events occurred. Kaplan-Meier survival estimation indicated worse event-free survival rates in patients with dilated ESV, dilated EDV, left ventricular ejection fraction (LVEF) ≤45% ΔESV ≥5 ml or ΔEDV ≥5 ml than in those without, whereas ΔEF ≤-5% did not predict events. Multivariate analysis demonstrated that LVEF ≤45% was the independent predictor for cardiac events. Nevertheless, ΔEDV ≥5 ml was also an independent parameter, in addition to LVEF ≤45%, to predict the combined endpoint of cardiac death, myocardial infarction, and revascularization, but excluding heart failure. These results indicate that post-ischemic stunning, as assessed by gated SPECT, is a marker for poor prognosis, particularly for ischemic cardiac events. (author)

  15. A partial defect in technetium-99m pyrophosphate image suggesting cardiac rupture following acute myocardial infarction

    We present the case of a 70-year-old woman with acute myocardial infarction who died of cardiac rupture on the 2nd hospital day. Dual isotope single photon emission tomography (SPET) using thallium-201 chloride and technetium-99m pyrophosphate (PYP) perforemd on the 2nd hospital day showed a large perfusion defect in the anteroseptal wall on 201Tl image and a increased accumulation on 99mTc-PYP image in the anterior area consistent with a partial defect. Autopsy performed 1 h after death revealed a tear in the left ventricular anterior wall consistent with the defect on the 99mTc-PYP image. We propose that the finding of a partial defect in 99mTc-PYP is an interesting finding which may be associated with cardiac rupture following acute myocardial infarction. (orig.)

  16. 201Tl+-labelled Prussian blue nanoparticles as contrast agents for SPECT scintigraphy

    Perrier, M.; Busson, M.; Massasso, G.; Long, J.; Boudousq, V.; Pouget, J.-P.; Peyrottes, S.; Perigaud, Ch.; Porredon-Guarch, C.; de Lapuente, J.; Borras, M.; Larionova, J.; Guari, Y.

    2014-10-01

    Prussian blue (PB) and its analogues on the nanometric scale are exciting nano-objects that combine the advantages of molecular-based materials and nanochemistry. Herein, we demonstrate that ultra-small PB nanoparticles of 2-3 nm can be easily labelled with radioactive 201Tl+ to obtain new nanoprobes as radiotracers for 201-thallium-based imaging.Prussian blue (PB) and its analogues on the nanometric scale are exciting nano-objects that combine the advantages of molecular-based materials and nanochemistry. Herein, we demonstrate that ultra-small PB nanoparticles of 2-3 nm can be easily labelled with radioactive 201Tl+ to obtain new nanoprobes as radiotracers for 201-thallium-based imaging. Electronic supplementary information (ESI) available: Experimental details and procedures, toxicological data, PXRD, TEM images, kinetics and adsorption isotherms, SPECT/CT images, Tl+ captation profiles. See DOI: 10.1039/c4nr03044c

  17. Contamination and radiation exposure from 201Tl in patients undergoing dialysis after a nuclear medicine study

    Our institution is a major kidney research and transplant center. Hemodialysis patients that are scheduled for renal transplant are given a 201Tl stress test. Possible radiation exposure and contamination are of concern to attending personnel. We investigated this situation and found measurable activity in the effluent of patients receiving dialysis but no significant contamination of equipment. We determined that dialysis personnel received minimal radiation exposure

  18. Difference in 201TlCl accumulation mechanism in brain tumors. A comparison of their Na+-K+ ATPase activities

    The accumulation levels of 201TlCl and Na+ -K+ ATPase activity in tumor tissue were compared among glioblastoma, benign glioma and meningioma to study the difference in the mechanism of 201TlCl accumulation. The subjects were 19 cases comprised of 6 glioblastoma, 2 oligodendroglioma, 1 fibrillary astrocytoma, 1 pilocytic astrocytoma and 9 meningioma. Preoperative 201TlCl SPECT was performed in all the cases, and Thallium Index (TL index) was calculated by a ratio of 201TlCl in the tumor area and the contralateral area. In addition, cell membrane was extracted from the tumor tissue collected intraoperatively to determine Na+ -K+ ATPase activity. No statistically significant difference in TL index was noted between the glioblastoma group (6.97±2.67) and the meningioma group (5.87±1.99). This fact showed that there was no difference in the accumulation level of 201TlCl between the two groups. On the other hand, the glioblastoma group indicated a higher value of Na+ -K+ ATPase activity (49.13±43.76 μmole/hour/mg protein) than the meningioma group (7.73±13.84 μmol/hour/mg protein) (p+ -K+ ATPase activity in 201TlCl accumulation in glioblastoma and the influences of other accumulation mechanism than Na+ -K+ ATPase activity such as the volume of intratumoral vascular bed in meningioma. (author)

  19. Diagnosis of pancreatic cancer using 201Tl-chloride and a three-head rotating gamma camera SPECT system

    201Tl SPECT was performed on 17 patients with pancreatic cancer or chronic pancreatitis using a three-head rotating gamma camera SPECT system. In 7 of 10 patients with pancreatic cancer, the lesions were clearly delineated by 201Tl SPECT. Whereas the lesion of 30 mm in diameter was visualized, a large tumor of 80 mm in diameter could not be visualized. Namely, it was thought that 201Tl uptake by pancreatic cancer might be well correlated with tumor blood flow and/or its histological subtype rather than with tumor size. In 5 of 7 patients with chronic pancreatitis, no uptake by the pancreas was shown. The sensitivity, specificity, and accuracy in diagnosing pancreatic cancer by 201Tl SPECT were 70%, 71%, and 71%, respectively. The present results obtained by 201Tl SPECT were thought satisfactory enough to evaluate pancreatic cancer under the present conditions where there was no useful imaging agent for visualizing pancreatic cancer by SPECT. 201Tl SPECT is expected to be a new diagnostic tool for investigation of pancreatic tumorous lesion. (author)

  20. Quantitative evaluation of myocardial single-photon emission tomographic imaging: application to the measurement of perfusion defect size and severity

    A new method is described for precise quantitative analysis of the relative three-dimensional distribution of myocardial tracers. The system uses a 360 elliptical sampling of radial slices to create activity profiles. These are then positioned onto a common centre at the same angular coordinates as the corresponding radial slice reconstruction planes to generate a two-dimensional polar summary display. Abnormal distribution is then identified by automatic comparison of the patient polar map with the threshold of a normal database defined on a pixel by pixel basis as the normal mean -2.5 SD. Our stress and rest databases currently comprise 34 and 24 studies for sestamibi and tetrofosmin respectively. The present method differs from currently available software in two major respects. Calculation of defect extent takes into account the surface distortion resulting from planar projection by using pixel by pixel weighted factors but it is otherwise overestimated as a result of the limited resolution of the imaging system. Integrating defect severity and extent, our hypoperfusion index appeared to accurately estimate the true defect size in our phantom model (r=0.993). The reproducibility of analysis was 6.24% in phantom studies and 3.10% in patient studies including repeated acquisitions. Applied to a well-documented population of 80 patients, this method resulted in an 86% sensitivity and a 78% specificity for overall coronary artery disease detection with reference to the angiographic data. (orig.). With 14 figs., 2 tabs

  1. Significance of exercise-induced ST segment depression in patients with myocardial infarction involving the left circumflex artery. Evaluation by exercise thallium-201 myocardial single photon emission computed tomography

    The significance of exercise-induced ST segment depression in patients with left circumflex artery involvement was investigated by comparing exercise electrocardiography with exercise thallium-201 single photon emission computed tomography (Tl-SPECT) and the wall motion estimated by left ventriculography. Tl-SPECT and exercise electrocardiography were simultaneously performed in 51 patients with left circumflex artery involvement (angina pectoris 30, myocardial infarction 21). In patients with myocardial infarction, exercise-induced ST depression was frequently found in the V2, V3 and V4 leads. In patients with angina pectoris, ST depression was frequently found in the II, III, aVF, V5 and V6 leads. There was no obvious difference in the leads of ST depression in patients with myocardial infarction with ischemia and without ischemia on Tl-SPECT images. In patients with myocardial infarction, the lateral wall motion of the infarcted area evaluated by left ventriculography was more significantly impaired in the patients with ST depression than without ST depression (p<0.01). Exercise-induced ST depression in the precordial leads possibly reflects wall motion abnormality rather than ischemia in the lateral infarcted myocardium. (author)

  2. Increased accuracy of single photon emission computed tomography (SPECT myocardial perfusion scintigraphy using iterative reconstruction of images

    Stević Miloš

    2016-01-01

    Full Text Available Background/Aim. Filtered back projection (FBP is a common way of processing myocardial perfusion imaging (MPI studies. There are artifacts in FBP which can cause falsepositive results. Iterative reconstruction (IR is developed to reduce false positive findings in MPI studies. The aim of this study was to evaluate the difference in the number of false positive findings in MPI studies, between FBP and IR processing. Methods. We examined 107 patients with angina pectoris with MPI and coronary angiography (CAG, 77 man and 30 woman, aged 32−82. MPI studies were processed with FBP and with IR. Positive finding at MPI was visualization of the perfusion defect. Positive finding at CAG was stenosis of coronary artery. Perfusion defect at MPI without coronary artery stenosis at CAG was considered like false positive. The results were statistically analyzed with bivariate correlation, and with one sample t-test. Results. There were 20.6% normal, and 79.4% pathologic findings at FBP, 30.8% normal and 69.2% pathologic with IR and 37.4% normal and 62.6% pathologic at CAG. FBP produced 19 false-positive findings, at IR 11 false positive findings. The correlation between FBP and CAG was 0.658 (p < 0.01 and between IR and CAG 0.784 (p < 0.01. The number of false positive findings at MPI with IR was significantly lower than at FBP (p < 0.01. Conclusion. Our study shows that IR processing MPI scintigraphy has less number of false positive findings, therefore it is our choice for processing MPI studies.

  3. Transient ischemic stunning of the myocardium in stress thallium-201 gated SPET myocardial perfusion imaging: segmental analysis of myocardial perfusion, wall motion and wall thickening changes

    Prolonged and persistent myocardial stunning has recently been demonstrated using technetium-99m sestamibi gated single-photon emission tomography (SPET) myocardial perfusion imaging post exercise or pharmacological stress test. In this study, we investigated the early postischemic transient myocardial stunning on early and delayed poststress thallium-201 gated SPET myocardial perfusion imaging using segmental wall motion (WM) and wall thickening (WT) analysis. A total of 1,680 segments from 84 patients' studies (53 men and 31 women, mean age 60 years) were evaluated on both early and delayed thallium-201 gated SPET treadmill exercise (59) or dobutamine stress (25) myocardial perfusion imaging. Semiquantitative analysis of perfusion, WM and WT in all segments was performed by two observers. Segments were classified according to changes in WM and WT between early and delayed images into normal, fixed abnormality, or improved abnormality (transient stunning), and were further classified according to changes in perfusion into normal, fixed defects, or ischemic. There were significant correlations between perfusion and WM, perfusion and WT, and WM and WT segmental scores on both early and delayed images. Transient stunning was seen significantly (P201Tl myocardial perfusion imaging using WM and WT was comparable, and results correlated well with the myocardial perfusion assessment. Early transient myocardial stunning was frequently observed in ischemic segments and was related to the severity of myocardial ischemia. (orig.)

  4. Myocardial perfusion assessed by contrast echocardiography and single photon emission computed tomography in the evaluation of patients with acute chest pain and normal electrocardiogram

    Aim : Evaluation of diagnostic accuracy of myocardial contrast echocardiography (MCE) in comparison with single-photon emission computed tomography (SPECT) for the detection of myocardial ischemia in patients with acute chest pain. Material and Methods : Eighteen patients (pts) with chest pain lasting ≥30 minutes, occurring within 6 hours of emergency room presentation and a normal or no diagnostic electrocardiogram were studied. Pts underwent rest MCE and SPECT. For both exams myocardial perfusion was assessed in the same 7 segments (apical, anterior, inferior, anteroseptal, inferoseptal, lateral and posterior) of left ventricle. A total of 126 segments were analyzed. Images were classified as positive for ischemia if they had a perfusion defect. Coronary angiography was performed if MCE or SPECT images were classified as positive for ischemia or by clinical indication. Otherwise the patients underwent stress SPECT. Significant coronary artery disease (CAD) was defined as ≥70% stenosis in a major coronary artery or its branches. Final diagnosis of an acute coronary event (ACE) was established in the presence of positive findings in MCE or SPECT in addition to significant CAD in the corresponding territory. Kappa statistics were calculated to evaluate the concordance between MCE and SPECT. κ values of ≤0.4, >0.4 and >0.7 indicate fair, good and excellent agreement, respectively. Results: Thirteen out of 18 pts underwent coronary angiography (seven pts had positive findings on SPECT, 2 on MCE, 2 on both exams and 1 had clinical indication). Significant CAD was detected on six. Five pts underwent stress SPECT and no perfusion defect was detected. Therefore, six pts (33.3%) had an ACE and 12 (66.6%) had not. There were no statistical differences between groups according to age, gender, duration of pain, free pain interval, presence of risk factors and antecedents. Concordance between MCE and SPECT for evaluation of perfusion defects showed a ? coefficient of 0

  5. Correlation of myocardial perfusion single photon emission computed tomography with coronary artery calcium score in coronary artery disease- An Indian perspective

    Full text: Objectives: The consequences of atherosclerosis can be detected by coronary artery calcium score (CACS) and stress induced myocardial ischemia on myocardial perfusion single photon emission computed tomography (MPS). We assessed the relationship between stress induced myocardial ischemia on (MPS) and magnitude of CACS by 64 slice computed tomography (CT) in patients undergoing both tests. Methods: Our study included 59 patients with no earlier history of coronary artery disease (CAD) of both sexes (males-47, females-12) in age group of 34-69 years. Our patients were referred by cardiologists after they underwent CACS. Of these 37 patients (63%) presented with symptoms which included chest pain (non-anginal, anginal, atypical) presence or absence of shortness of breath, and rest (37%) were asymptomatic. For each patient coronary risk factors were noted. All these patients underwent CACS and rest and stress MPS one-day protocol with Tc99m sestamibi within 7 days. According to CACS and symptoms, patients were divided into four groups, group A - asymptomatic 100 n=13, group D - symptomatic >100 (n=11). The incidence of inducible ischemia in MPS was compared to the magnitude of CACS abnormality. Results: There were 21 patients (36%) with ischemic MPS. According to groups, group A - 11%(n=1), groupB- 38%(n=10), groupC- 30%(n=4) and group D- 54%(n=6) had ischemic MPS. From the above we observed that incidence of ischemic MPS is more with increasing CACS. And also it is noted that it is more frequent in patients who presented with symptoms irrespective of CACS who are at short-term risk. In negative MPS, CACS may be useful in long term risk stratification in finding out subclinical atherosclerosis. Conclusion: The general perception is that the CACS is a good tool for long-term risk stratification but it may be applicable to those patients with no significant risk factors. When there are risk factors MPS is a better indicator for risk stratification for CAD

  6. Initial multicentre experience of high-speed myocardial perfusion imaging: comparison between high-speed and conventional single-photon emission computed tomography with angiographic validation

    High-speed (HS) single-photon emission computed tomography (SPECT) with a recently developed solid-state camera shows comparable myocardial perfusion abnormalities to those seen in conventional SPECT. We aimed to compare HS and conventional SPECT images from multiple centres with coronary angiographic findings. The study included 50 patients who had sequential conventional SPECT and HS SPECT myocardial perfusion studies and coronary angiography within 3 months. Stress and rest perfusion images were visually analysed and scored semiquantitatively using a 17-segment model by two experienced blinded readers. Global and coronary territorial summed stress scores (SSS) and summed rest scores (SRS) were calculated. Global SSS ≥3 or coronary territorial SSS ≥2 was considered abnormal. In addition the total perfusion deficit (TPD) was automatically derived. TPD >5 % and coronary territorial TPD ≥3 % were defined as abnormal. Coronary angiograms were analysed for site and severity of coronary stenosis; ≥50 % was considered significant. Of the 50 patients, 13 (26 %) had no stenosis, 22 (44 %) had single-vessel disease, 6 (12 %) had double-vessel disease and 9 (18 %) had triple-vessel disease. There was a good linear correlation between the visual global SSS and SRS (Spearman's ρ 0.897 and 0.866, respectively; p < 0.001). In relation to coronary angiography, the sensitivities, specificities and accuracies of HS SPECT and conventional SPECT by visual assessment were 92 % (35/38), 83 % (10/12) and 90 % (45/50) vs. 84 % (32/38), 50 % (6/12) and 76 % (38/50), respectively (p < 0.001). The sensitivities, specificities and accuracies of HS SPECT and conventional SPECT in relation to automated TPD assessment were 89 % (31/35), 57 % (8/14) and 80 % (39/49) vs. 86 % (31/36), 77 % (10/13) and 84 % (41/49), respectively. HS SPECT allows fast acquisition of myocardial perfusion images that correlate well with angiographic findings with overall accuracy by visual assessment better

  7. Initial multicentre experience of high-speed myocardial perfusion imaging: comparison between high-speed and conventional single-photon emission computed tomography with angiographic validation

    Neill, Johanne [University College London Hospital, Institute of Nuclear Medicine, London (United Kingdom); The Prince Charles Hospital, Brisbane (Australia); Prvulovich, Elizabeth M.; Bomanji, Jamshed B. [University College London Hospital, Institute of Nuclear Medicine, London (United Kingdom); Fish, Matthews B. [Sacred Heart Medical Center (SHMC), Springfield, OR (United States); Berman, Daniel S.; Slomka, Piotr J. [Cedars-Sinai Medical Center, Los Angeles, CA (United States); Sharir, Tali [Procardia Maccabi Healthcare Services (PMHS), Tel Aviv (Israel); Martin, William H. [Vanderbilt University Medical Center (VUMC), Nashville, TN (United States); DiCarli, Marcelo F. [Brigham and Women' s Hospital (BWH), Boston, MA (United States); Ziffer, Jack A. [Baptist Hospital of Miami (BHM), Miami, FL (United States); Shiti, Dalia [Spectrum-Dynamics, Caesarea (Israel); Ben-Haim, Simona [University College London Hospital, Institute of Nuclear Medicine, London (United Kingdom); Chaim Sheba Medical Center, Department of Nuclear Medicine, Tel-Hashomer (Israel)

    2013-07-15

    High-speed (HS) single-photon emission computed tomography (SPECT) with a recently developed solid-state camera shows comparable myocardial perfusion abnormalities to those seen in conventional SPECT. We aimed to compare HS and conventional SPECT images from multiple centres with coronary angiographic findings. The study included 50 patients who had sequential conventional SPECT and HS SPECT myocardial perfusion studies and coronary angiography within 3 months. Stress and rest perfusion images were visually analysed and scored semiquantitatively using a 17-segment model by two experienced blinded readers. Global and coronary territorial summed stress scores (SSS) and summed rest scores (SRS) were calculated. Global SSS {>=}3 or coronary territorial SSS {>=}2 was considered abnormal. In addition the total perfusion deficit (TPD) was automatically derived. TPD >5 % and coronary territorial TPD {>=}3 % were defined as abnormal. Coronary angiograms were analysed for site and severity of coronary stenosis; {>=}50 % was considered significant. Of the 50 patients, 13 (26 %) had no stenosis, 22 (44 %) had single-vessel disease, 6 (12 %) had double-vessel disease and 9 (18 %) had triple-vessel disease. There was a good linear correlation between the visual global SSS and SRS (Spearman's {rho} 0.897 and 0.866, respectively; p < 0.001). In relation to coronary angiography, the sensitivities, specificities and accuracies of HS SPECT and conventional SPECT by visual assessment were 92 % (35/38), 83 % (10/12) and 90 % (45/50) vs. 84 % (32/38), 50 % (6/12) and 76 % (38/50), respectively (p < 0.001). The sensitivities, specificities and accuracies of HS SPECT and conventional SPECT in relation to automated TPD assessment were 89 % (31/35), 57 % (8/14) and 80 % (39/49) vs. 86 % (31/36), 77 % (10/13) and 84 % (41/49), respectively. HS SPECT allows fast acquisition of myocardial perfusion images that correlate well with angiographic findings with overall accuracy by visual

  8. An experimental animal model of chronic myocardial hibernation: comparative study of cine-MR, myocardial single photon emission computed tomography and pathology

    Objective: To establish the chronic low-flow myocardial hibernation animal model in pigs, and to assess the diagnostic value for myocardial hibernation by using various imaging methods. Methods: A total of 13 miniswine (30-40 kg) were used. All animals underwent general anesthesia and orotracheal intubation while the animals were mechanically ventilated. Under sterile conditions, left ventriculography and coronary angiography were performed by introduction of catheter into the right femoral artery. Further, a left anterolateral thoracotomy was performed in the third intercostal space. The proximal LCX was dissected free to allow placement of an ameroid constrictor. More than 1 month later, left ventriculography and coronary angiography were performed again, followed by cine-MRI at rest and during stress with low-dose of dobutamine (5μg·kg-1·min-1), respectively. Traditional and/or breath-hold cine-MRI were used to evaluate regional left ventricular wall motion, corresponding to basal, midventricular and apical short-axis tomograms. Regional wall motion score index (WMSI) was calculated. At the same time 99mTc-MIBI myocardial SPECT was performed at rest and during nitroglycerin administration, respectively. All animals were finally sacrificed for pathological examination. Triphenyl tetrazolium chloride (TTC) staining was used to assess the myocardial infarction. Electron microscopy was used to identify myocardial cellular changes characteristic of hibernating myocardium. Results: Three pigs died during surgery or within two weeks after surgery. One pig died of anesthesia during SPECT examination, 1 pig suffered from aneurysm, and another one pig showed negative findings. The other 7 pigs were found with hypokinetic (n=4) or akinetic (n=3) myocardial regions related to stenosed LCX (70%-99%). Resting cine-MRI demonstrated decreased regional motion of the lateral and posteroinferior walls (ischemic regions) of the left ventricle (n=7), compared with the nonischemic

  9. Clinical usefulness of {sup 18}FDG-PET in primary lung cancer. Comparison with {sup 201}Tl-SPECT

    Nishikawa, Takahiro [Kanazawa Medical Univ., Uchinada, Ishikawa (Japan)

    1997-03-01

    Forty patients with pulmonary nodular lesions had PET imaging performed. Within a week, all patients were investigated with the triple-headed SPECT system and by CT. The PET and SPECT images were compared qualitatively and quantitatively. For quantitative analysis, ROIs were selected in areas of the tumor showing the highest tracer accumulation and in the normal areas of contralateral lung. The tumor to nontumor activity ratio (T/N ratio) was calculated. In thirty-three patients with primary lung cancer, the sensitivity of {sup 18}FDG-PFT, {sup 201}Tl-SPECT were 93.6%, 84.8%, respectively. In the detection of lung cancer, {sup 18}FDG-PET provided a higher sensitivity than {sup 201}Tl-SPECT. Neither techniques visualized any lesion in two patients who had bronchioloalveolar carcinoma. Among the patients showing increased tracer accumulation, the T/N ratio was significantly higher with {sup 18}FDG-PET than with {sup 201}Tl-SPECT. However, there was significant positive correlation between the {sup 18}FDG T/N ratio and the {sup 201}Tl delayed ratio. We assessed the association between cell differentiation and {sup 18}FDG or {sup 201}Tl uptake in 17 patients with adenocarcinoma of the lung. Only {sup 18}FDG uptake might be associated with cell differentiation of adenocarcinoma. Thirty patients with pulmonary nodular lesion underwent an operation and the results of {sup 18}FDG-PET, {sup 201}Tl-SPECT were compared between malignant and benign nodules in {sup 18}FDG uptake and {sup 201}Tl uptake. {sup 18}FDG uptake and {sup 201}Tl uptake showed no significant differences in malignant nodules or benign nodules. Twenty-one patients underwent thoracotomy and the results of {sup 18}FDG-PET, {sup 201}Tl-SPECT and CT were compared with the pathological findings of the mediastinal lymph nodes. In the detection of mediastinal lymph node metastasis from lung cancer, sensitivity and specificity were 33.3% and 77.8% for CT, 33.3% and 94.4% for {sup 201}Tl SPECT and 66.7% and 88

  10. Single photon emission computed tomography (SPECT)

    The functional state of organs can be imaged by their accumulation of single photon emitter like 99mTc (γ-ray energy 140 keV), 201Tl (73 keV) and 201I (159 keV) with computed tomography. The emitted γ-ray is collimated to reach the NaI (Tl) detector for specifying its direction, which is called as the scintillation camera or gamma camera. The camera rotating around the patient gives the SPECT images. The NaI (Tl) detector is suitable for converting 60-300 keV γ-ray to fluorescence through the photoelectric effect. Photomultiplier receiving the fluorescence outputs X/Y signals for the emitting position and Z signal (energy) separately, giving imaging data. 3D images can be re-constructed by either method of the filtered back projection or maximum likelihood-expectation maximization. For quantitative reconstruction, correction of γ-ray absorption in water, of scattering and of collimator opening is necessary. Recently, semiconductor-detectors like CdZnTe and CdTe are being utilized in place of NaI for better resolution, which will reduce the size of the camera. Further, a camera with coincidence circuit for positron has appeared and will be applicable for both SPECT and PET. Compton camera having 2-step detectors without collimator is now under development. (N.I.)

  11. Effect of eating on thallium myocardial imaging

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

    1986-02-01

    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 /sup 201/Tl images were interpreted in blinded fashion for global myocardial and pulmonary clearance of /sup 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 /sup 201/Tl images causes increased /sup 201/Tl myocardial clearance rates and may alter /sup 201/Tl myocardial redistribution over time.

  12. Effect of eating on thallium myocardial imaging

    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 201Tl images were interpreted in blinded fashion for global myocardial and pulmonary clearance of 201Tl 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 201Tl images causes increased 201Tl myocardial clearance rates and may alter 201Tl myocardial redistribution over time

  13. Activity determination of a 201Tl solution by 4πβ-γ and sum-peak coincidence methods

    201Tl is used in nuclear medicine in cardiac imaging for evaluating the injury level in cardiac muscle at rest and exercise. In this work the activity concentration of a 201Tl radioactive solution has been absolutely determined using the 4πβ-γ coincidence and sum-peak coincidence methods. The presence of 202Tl radioactive impurity that imposes some difficult in the activity measurements was taken into account in the measurements. In the sum-peak method a planar germanium detector was used. The half-lives were evaluated by the reference source method and the results obtained were (3.033 ± 0.004) d and (12.320 ± 0.163) d, respectively, for 201Tl and 202Tl. (author)

  14. Single-photon imaging

    Seitz, Peter

    2011-01-01

    The acquisition and interpretation of images is a central capability in almost all scientific and technological domains. In particular, the acquisition of electromagnetic radiation, in the form of visible light, UV, infrared, X-ray, etc. is of enormous practical importance. The ultimate sensitivity in electronic imaging is the detection of individual photons. With this book, the first comprehensive review of all aspects of single-photon electronic imaging has been created. Topics include theoretical basics, semiconductor fabrication, single-photon detection principles, imager design and applications of different spectral domains. Today, the solid-state fabrication capabilities for several types of image sensors has advanced to a point, where uncoooled single-photon electronic imaging will soon become a consumer product. This book is giving a specialist´s view from different domains to the forthcoming “single-photon imaging” revolution. The various aspects of single-photon imaging are treated by internati...

  15. Therapeutic effects of coenzyme Q10 on dilated cardiomyopathy. Assessment by 123I-BMIPP myocardial single photon emission computed tomography (SPECT). A multicenter trial in Osaka University Medical School Group

    To evaluate therapeutic effects of Coenzyme Q10 (CoQ10), 15 patients with dilated cardiomyopathy were investigated by 123I-BMIPP myocardial single photon emission computed tomography (SPECT). The BMIPP defect score was determined semiquantitatively by using representative short and long axial SPECT images. Mean BMIPP defect score with CoQ10 treatment was significantly low, 7.7±6.1 compared to 12.7±7.4 without CoQ10 treatment. On the other hand, in 8 patients of dilated cardiomyopathy, % fractional shortening using echocardiography was not different before and after CoQ10 treatment. In conclusion, 123I-BMIPP myocardial SPECT was proved to be sensitive to evaluate the therapeutic effects of CoQ10, which improve myocardial mitochondrial function, in the cases of dilated cardiomyopathy. (author)

  16. Preparation and evaluation of [201Tl](III)-DTPA complex for cell labeling

    Due to interesting physical properties and wide availability of 201Tl as a SPECT radionuclide, the incorporation of this nuclide into DTPA for cell labeling was targeted. Thallium-201 (T1/2 = 3.04 d) in Tl+ form was converted to Tl3+ cation in the presence of O3/6M HCl and di-isopropyl ether, controlled by RTLC/gel electrophoresis methods. The final evaporated activity reacted with cDTPA in normal saline to yield [201Tl](III)DTPA at room temperature after 0.5 hour, followed by solid phase extraction purification using C18 Sep-Pak column (radiochemical yield >95%). Radiochemical purity of more than 99% was obtained using RTLC with specific activity of about 260 GBq/mmol. The stability of the tracer was checked in the final product in the presence of human serum at 37 deg C up to 3 days. The partition coefficient was also measured. The labeled compound was used in red blood cell (RBC) labeling. The cell uptake ratio was determined at 4, 25 and 37 deg C up to 3 hours. (author)

  17. Estimation of internal radiation due to the administration of 201Tl

    Today, radioactive pharmaceuticals are widely used for the purpose of diagnosis in the field of nuclear medicine, bringing many bits of useful informations. On the other hand, radiation is known to be bionegative, having possibility of inducing stochastic effects such as cancers and genetic effects even in the relatively low dose region together with non-stochastic effects which could result from radiation exposure higher than threshold value. The author has published a series of papers with regard to the estimation of radiation exposures for medical use based on three principles of justification, optimization and limitation. In this paper, radiation dose by a radiation worker due to 201Tl administration for the diagnosis of a cardiac disease was evaluated based on the measurement of concentration of radioactive isotope excreted in urine over 1 month. Internal radiation dose due to the administration of 111 MBq (3 mCi) 201Tl was estimated to be 6.1 mSv (610 mrem) which agreed well with the result reported by H.L. Atkins (1977) and exceeded the occupational exposure (approximately 60 mrem over 12 years). The author suggested the importance of reducing medical exposure. (author)

  18. Effect of thallium-201 blood levels on reversible myocardial defects

    To determine if 201Tl plasma blood levels correlate with the presence of reversible myocardial defects during exercise testing, 14 patients with stable coronary artery disease underwent two separate exercise 201Tl stress tests. Between initial and delayed imaging, on one test the patients drank an instant breakfast drink (eating) and on the other they drank an equivalent volume of water as a control (H2O). Thallium-201 imaging was performed immediately postexercise, immediately after eating/H2O and 210 min after eating/H2O. Between initial and immediate post eating/H2O images 201Tl reversible defects occurred in 27/38 regions in the H2O test versus 15/38 regions in the eating test (p = 0.02). Over this early time period, plasma 201Tl activity was significantly higher in the H2O test than eating test (p less than 0.05). In conclusion, early reversal of 201Tl defects may, in part, be the result of higher plasma 201Tl activity early after initial postexercise 201Tl imaging

  19. Detection of myocardial viability by means of Single Proton Emission Computed Tomography (Perfused SPECT) dual 201 Tl (rest of 15 minutes, 24 late hours and 24 hours reinjection) and gated-SPECT 99m Tc-SESTAMIBI in effort or stimulation of the coronary reserves

    The objective of this work was to determine if the images of SPECT 201 TI in rest of 15 minutes, 24 late hours and Gated-SPECT 99m Tc-SESTAMIBI in effort or stimulation of coronary reservation correlate with the study of 24 hours post reinjection of 201TI to determine the presence of having knitted viable myocardium. Material and methods: 29 patients were studied with coronary arterial illness (EAC) to who are carried out SPECT 201 TI in rest with images of 15 minutes, 24 late hours and 24 hours reinjection, by means of the administration of 201TI to dose of 130 MBq and reinjection with 37 MBq. and Gated-SPECT 99mTc-SESTAMIBI in effort or stimulation of coronary reservation, later to the administration of 1110 MBq. Results: 29 patients were included according to inclusion approaches and exclusion, of those which 22 (75.86%) they correspond at the masculine sex and 7 (24.13%) to the feminine one, with an average of 62.1 year-old age, 2320 segments myocardial were analysed so much it is phase post-effort as rest; they were diagnosed a total of 264 segments with heart attack, of which viability myocardium was observed in 174 segments. The statistical tests are analysis of frequencies. The non parametric test of Wilcoxon and Mann-Whitney. Conclusions: the viability myocardial at the 24 late hours and 24 hours reinjection was similar; significant difference exists between the study of 15 minutes and 24 hours reinjection, ischemic illness was also demonstrated in territories different to the heart attack area in the studies of 15 minutes, late 24 hours and 24 hours reinjection. (Author)

  20. The value of gallium-67 and thallium-201 whole-body and single-photon emission tomography images in dialysis-related β2-microglobulin amyloid

    The aim of this study was to investigate the value of gallium-67 and thallium-201 whole-body and single-photon emission tomography (SPET) images in long-term dialysis patients in whom dialysis-related β2-microglobulin amyloid (β2-MA) was clinically suspected. Twenty-three patients who had received dialysis for at least 10 years were included in the study. A technetium-99m methylene diphosphonate (MDP) whole-body scan was performed in all of the patients. If there was any MDP accumulation in the articular and/or peri-articular region, 67Ga and 201Tl whole-body and SPET images were then acquired. If any 67Ga and/or 201Tl uptake was observed, a CT-guided biopsy was done. In those patients who had articular and/or peri-articular uptake of 99mTc MDP, 67Ga and/or 201Tl and who were pathologically proven to have β2-MA, 99mTc MDP, 67Ga and 201Tl whole-body scans and SPET were carried out again, both 3 months and 1 year after initiation of treatment. This served to evaluate the therapeutic effect and allowed comparison with the clinical findings. Of the 23 patients, eight had abnormal 99mTc MDP uptake. Among these eight, six had intense 99mTc MDP, 67Ga and 201Tl uptake in the articular and peri-articular regions before medication. Three months after the start of treatment, there were very marked decreases in uptake on both the 67Ga and 201Tl scans but less obvious changes in uptake of 99mTc-MDP. In comparison with the other clinical manifestations such as limitation in range of motion, the more the painful disability improved, the less was the uptake on both 67Ga and 201Tl scans. There were virtually no differences in uptake pattern between the three scans of each radiopharmaceutical obtained for each patient in both 3 months and 1 year after initial of treatment. It is concluded that 99mTc-MDP whole-body bone scan can both detect active and pre-existing inactive deposits of β2-MA. 67Ga and 201Tl scans are helpful to differentiate active from inactive deposits of β2-MA

  1. Single photon quantum cryptography

    Beveratos, Alexios; Brouri, Rosa; Gacoin, Thierry; Villing, André; Poizat, Jean-Philippe; Grangier, Philippe

    2002-01-01

    We report the full implementation of a quantum cryptography protocol using a stream of single photon pulses generated by a stable and efficient source operating at room temperature. The single photon pulses are emitted on demand by a single nitrogen-vacancy (NV) color center in a diamond nanocrystal. The quantum bit error rate is less that 4.6% and the secure bit rate is 9500 bits/s. The overall performances of our system reaches a domain where single photons have a measurable advantage over ...

  2. Absorbed radiation to the nuclear medicine nurses from patients administered 201Tl and 99mTc- MIBI

    People who have administrated radiopharmaceuticals could be a source of radiation to their relatives, medical nurses, and people who have contact them. In this study, the dose rates at various distances of 5, 10,50 and 100 cm from 70 patients, who were administered diagnostic amounts of 201Tl -Chloride and 99mTc -MIBI, was measured using an ionization chamber. For determination of external radiation dose to the nurses the radiations in three deferent interval times have measured. The maximum values of external dose rates of 201Tl and 99mTc-MIBI were 11.2μSv/h ±2.3 and 43.1μSv/h ±11.9 respectively at 5 cm from the patients. Significant exposure from patients after injection of 99mTc -MIBI was limited on the day of administration. Departure doses rate of 201Tl fell gradually so by 3 days after administration was significant. Maximum and average absorbed dose of nuclear medicine staff for one 201Tl scan was 4.6 and 2.7μSv/h, and for 99mTc-MIBI was 18.1 and 9.8μSv/h in a working day. (author)

  3. Absorbed radiation to the nuclear medicine nurses from patients administered 201Tl and 99mTc- MIBI

    People who have administrated radiopharmaceuticals could be a source of radiation to their relatives, medical nurses, and people who have contact them. In this study, the dose rates at various distances of 5, 10,50 and 100cm from 70 patients, who were administered diagnostic amounts of 201Tl-Chloride and 99mTc-MIBI, was measured using an ionization chamber. For determination of external radiation dose to the nurses the radiations in three deferent interval times have measured. The maximum values of external dose rates of 201Tl and 99mTc- MIBI were 11.2μSv/h ±2.3 and 43.1μSv/h ±11.9 respectively at 5cm from the patients. Significant exposure from patients after injection of 99mTc-MIBI was limited on the day of administration. Departure doses rate of 201Tl fell gradually so by 3 days after administration was significant. Maximum and average absorbed dose of nuclear medicine staff for one 201Tl scan was 4.6 and 2.7μSv/h, and for 99mTc-MIBI was 18.1 and 9.8μSv/h in a working day. (author)

  4. Sympathetic reinnervation in cardiac transplants: 123I-MIBG and 201Tl/99mTc-MIBI scintigraphy

    The purpose was to evaluate cardiac sympathetic reinnervation and hemodynamic changes after orthotopic heart transplantation (TPL). We performed 24 serial or followup cardiac 123I-MIBG imaging and rest 201Tl/99mTc-MIBI dipyridamole stress gated myocardial perfusion SPECT (g-MPS) in 15 patients (M:F=10:5;mean ages=34.5±13.0 yr; idiopathic:rheumatic=14:1; one heart lung TPL)(10.80 ±11.88 (1-48) mo) after TPL 123I-MIBG imagings were performed in anterior position 15 minutes, 4 and 24 hours after i.v. injection of 148 MBq 123I MIBG. Image quantitation was based on the ratio of heart to mediastinal MIBG uptake (HMR) Compared to HMR on 15 min images (1.48 ± 0.28), neither four nor 24 hour delayed images (1.26 ± 0.23 vs. 1.06 ± 0.26: p<0.05, respectively, ANOVA) showed definite delayed localization of MIBG. 12 subjects with <13 (4.9 ±3.7) months after TPL had no visible 123I-MIBG uptake on early 15 min imaging however, 12 subjects with 13 to 48(28.6±12.8) months had visible cardiac 123I-MIBG uptake (HMR: 1.65±0.21 vs. 1.32±0.26; p=0.002). One-year followup 123I-MIBG scintigraphy in nine pts showed significantly increased HMR(1.40±0.31 to 1.61±0.16, p<0.05) but a plateau was reached at HMR value of 2.0, which was still lower than 3.0 in normal controls. Plasma NE was increased according to I-123 MIBG myocardial uptake. Annual G-MPS detected an allograft atherosclerosis in one pt and showed progressive normalization of tachycardia and significant deterioration of LVEF and cardiac indices according to severity of rejection. To dipyridamole stress, transplant heats showed significant subnormal hemodynamic responses. Partial sympathetic late reinnervation can occur <1 year after TPL, and reached a plateau of two-third of normal value. G-MPS seems to be a useful screening test for the detection of allograft atherosclerosis and rejection

  5. Comparisons of 131I, 201Tl and 99mTc activity measurements in activimeters

    The correct administration to a patient of the a priori established activity of the radiopharmaceutical is an important factor to ensure the confidence in the diagnosis or the therapy efficiency, keeping at the same time the human exposure as low as possible. National comparisons for the 131I, 201Tl and 99mTc activity measurements in activimeters have been organized for the first time with the aim of obtaining information about the quality of the administration of radiopharmaceuticals. In the comparison run participated ten Cuban Nuclear Medicine Departments and the laboratories involved in the production of that kind of compounds. The comparison results, shown in this paper, have facilitated the identification of the problems and to initiate preventive actions. Furthermore, these results reflect the need of establishing Quality Systems in Nuclear Medicine in Cuba

  6. Combined 201Tl and 67Ga brain SPECT in patients with suspected central nervous system lymphoma or germinoma. Clinical and economic value

    Surgical resection is costly and an unfavorable prognostic factor for primary central nervous system (CNS) lymphoma and germinoma patients. The purpose of this study was to assess the diagnostic and economic impact of combined 201Tl and 67Ga brain SPECT on the management of patients suspected of having CNS lymphoma or germinoma. Sequential 201Tl and 67Ga brain SPECT was performed in 40 patients with cranial tumors to assess the diagnostic and economic impact of combined 201Tl and 67Ga SPECT on the management of patients suspected of having CNS lymphoma or germinoma. All intracranial masses were pathologically confirmed. The final diagnoses of a total of 47 foci were: 11 non-Hodgkin's lymphomas in 10 patients, 3 germinomas in 2 patients, 10 glioblastomas in 9 patients, 10 cerebral metastases in 8 patients, 13 meningiomas in 11 patients. Decision-tree sensitivity analysis for pretest probability regarding expected cost saving was performed for introduction of the combined study. All but one focus of CNS lymphomas or germinomas (92.9%, 13/14) exhibited more intense uptake of 67Ga than of 201Tl (p201Tl than of 67Ga (p67Ga-positive and 201Tl-positive pattern with more intense uptake of 67Ga than 201Tl probably suggests CNS lymphoma or germinoma. This combination study appears to be cost-effective only in patients highly suspected of having CNS lymphoma or germinoma. (author)

  7. Single-photon imaging

    The acquisition and interpretation of images is a central capability in almost all scientific and technological domains. In particular, the acquisition of electromagnetic radiation, in the form of visible light, UV, infrared, X-ray, etc. is of enormous practical importance. The ultimate sensitivity in electronic imaging is the detection of individual photons. With this book, the first comprehensive review of all aspects of single-photon electronic imaging has been created. Topics include theoretical basics, semiconductor fabrication, single-photon detection principles, imager design and applications of different spectral domains. Today, the solid-state fabrication capabilities for several types of image sensors has advanced to a point, where uncooled single-photon electronic imaging will soon become a consumer product. This book is giving a specialist's view from different domains to the forthcoming ''single-photon imaging'' revolution. The various aspects of single-photon imaging are treated by internationally renowned, leading scientists and technologists who have all pioneered their respective fields. (orig.)

  8. Evaluation of myocardial viability using sequential dual-isotope single photon emission tomography imaging with rest Tl-201/stress Tc-99m tetrofosmin in the prediction of wall motion recovery after revascularization

    In patients with coronary artery disease (CAD), differentiation between severely ischemic but potentially viable myocardium and irreversibly infarcted tissue is clinically important, particularly when revascularization procedures are considered. Although thallium (Tl) cardiac imaging has been shown to be a good tool for investigating myocardial viability in CAD, this tracer shows physical limitations, such as a low photon energy and long half-life. We assessed the results of a rest Tl-201/stress Tc-99m tetrofosmin protocol in subjects with prior anterior myocardial infarction. All of the patients had an akinetic or dyskinetic area and more than 75% stenosis in the left anterior descending artery. All of the patients underwent revascularization after the examination. We evaluated the improvement in wall motion after revascularization using the centerline method with contrast left ventricular angiography. Fourteen patients showed reversible defects with the rest Tl-201/stress Tc-99m tetrofosmin protocol or in additional Tl-201 24 h redistribution images. All 14 patients showed a significant improvement in wall motion after revascularization. Dual-isotope rest Tl-201/stress Tc-99m tetrofosmin single photon emission tomography data, acquired separately, may give fast and complete information about myocardial perfusion during stress and at rest, and on about myocardial viability. (author)

  9. Study of the influence of 200Tl in the activity determination of 201Tl using activity meters

    Full text: At the Ezeiza Atomic Center every week 201TI is produced, controlled and dispensed for medical use and distributed to most medical centers in Argentine. To determine exact activity before dispensing and expedition we have studied the response of a reference activity meter working as ionization chamber, in presence of its main impurity: 200Tl (Eg: 368 keV,1206 keV and others; T 1/2: 26,1 hs), to be found in approximately 4% concentration at the end of production process. It will decrease in function of the decay of 201Tl. According to the Argentine Farmacopea it must be less than 2% on distribution and use. This study was carried out simultaneously on two samples of the same origin. One was measured directly in activity meter on the 201Tl scale and the other, quantitatively diluted, in a high resolution gamma spectrometry system with a GeHP detector, and the relationship 200Tl / 201Tl was determined. This procedure was carried out several times during ten days in order to follow the activity meter response according to the decay of both isotopes of Thallium and their proportion. After several measurements when considering that 200Tl is absent, a line was drawn following the half-life of 201Tl . So were obtained readings without 200Tl impurities as well as the difference with experimental values. Series of measurements were carried out to assure sufficient precision and a curve of correction factor was determined for the proportion of 200Tl/201Tl . This curve is used for the calibration of 201Tl before dispensing . Eventually when up to 4%200Tl could be present at the moment of dispensing and it would create errors about 9% in excess; it will be necessary to correct . The limit of 1,8 % of 200Tl is given by the Control Group of National Atomic Energy Commission (CNEA) at the moment of dispensing, because it will mean an error by excess of less than 3%, accepted by nuclear medicine centers. Theoretical ideas are presented about ionization chamber response

  10. Single photon emission computerized tomography

    In this thesis two single-photon emission tomographic techniques are presented: (a) longitudinal tomography with a rotating slanting-hole collimator, and (b) transversal tomography with a rotating gamma camera. These methods overcome the disadvantages of conventional scintigraphy. Both detection systems and the image construction methods are explained and comparisons with conventional scintigraphy are drawn. One chapter is dedicated to the determination of system parameters like spatial resolution, contrast, detector uniformity, and size of the object, by phantom studies. In separate chapters the results are presented of detection of tumors and metastases in the liver and the liver hilus; skeletal diseases; various pathological aberrations of the brain; and myocardial perfusion. The possible use of these two ect's for other organs and body areas is discussed in the last chapter. (Auth.)

  11. Dual myocardial single photon emission computed tomography (SPECT) using thallium-201 and I-123-{beta}-methyl-i-pentadecanoic acid in patients with Duchenne's progressive muscular dystrophy

    Shimoyama, Katsuya [Kyorin Univ., Mitaka, Tokyo (Japan). School of Medicine

    1999-10-01

    Dual single photon emission computed tomography (SPECT) was performed in 31 patients with Duchenne's progressive muscular dystrophy (DMD) using {sup 123}I-{beta}-methyl pentadecanoic acid (BMIPP) for myocardial fatty acid metabolism and {sup 201}thallium (Tl)-chloride for myocardial perfusion. The left ventricle was divided into 9 segments, and accumulation of the radiotracers was assessed visually for each segment to calculate defect score for each tracer. There was some degree of decrease in myocardial accumulation of both tracers in all DMD patients. Reduced accumulation was most common at the apex (BMIPP: 67%, Tl: 63%), followed by the posterior wall, lateral wall, and anterior wall. On the other hand, reduced accumulation was less common at the septum. BMIPP showed a higher accumulation than Tl in all segments but the septum. When BMIPP defect score was larger than Tl defect score, BMIPP defect score tended to increase during 4 years follow-up (p<0.042). However, when Tl defect score was larger than BMIPP defect score, an increase in Tl defect score was slight. A significant negative correlation was found between the sum of the BMIPP and Tl defect scores and the left ventricular ejection fraction (LVEF) (r=0.66, p<0.0001). According to the histo-pathological study of two autopsied hearts, severe myocardial fibrosis was seen in segments with fixed perfusion defect. In addition, the mismatched segments of BMIPP defect score > Tl defect score revealed a slight fibrosis or normal myocardium. It can be concluded that the dual SPECT myocardial scintigraphy using BMIPP and Tl provides accurate information about disease progression of the heart in patients with DMD by detecting abnormalities of the myocardial metabolism of each substance, thereby enabling the assessment of left ventricular function. (author)

  12. Excitation functions of reactions of production of radioisotopes 201Tl, 201Pb, 201Bi (experimental and theoretical data)

    The results of calculations of charged particle induced reactions for the production of neutron deficient radioisotopes 201Tl, 201Pb, 201Bi and concomitant ones are discussed. The excitation functions for reactions 202Hg(p,xn), 197Au(a,xn), 203,205Tl(p,xn), 203,205Tl(d,xn), 203,205Tl(p,pxn), 204Pb(p,xn), 204Pb(p,p3n), 206Pb(p,6n), 206Pb(p,p5n), 207Pb(p,7n), 207Pb(p,p6n), 208Pb(p,xn) and 208Pb(p,p7n) are calculated on the base of statistical model in energy range up to 80 MeV. For the most reactions producing 201Tl the data on the calculated and practical yields under optimum conditions are given and the main admixture levels are pointed out. 30 refs., 9 figs

  13. Diagnostic accuracy of 201Tl SPECT·MRI in brain diseases and inter-reader variance of diagnostic performance

    Fifteen-four studies of 201Tl brain tumor SPECT were independently interpreted by 9 nuclear medicine physicians with and without reference magnetic resonance images in 2 separate sessions to define an effect of referring images, and inter-observer variations. The physicians were requested to detect foci of abnormal deposits, and to discriminate whether they were malignant or not according to 5-grade scaling of subjective diagnostic confidence. Receiver-operating characteristics (ROC) analysis was performed. Mean sensitivity for presence of lesions (SFP), and sensitivity and specificity for malignancy of 201Tl SPECT were 84, and 53 and 55%, which were changed to 94 and 74 and 55% after referring to the MR images. The SFP was significantly improved (p201Tl brain tumor SPECT has moderate sensitivity and specificity for malignancy, which is not improved by addition of anatomical reference images, that additional MR images reduce inter-observer variation of confidence on lesion presence, and that SPECT localization of lesions has great inter-observer variations. (author)

  14. Adsorption kinetics of 201Tl and migration of 99mTc in natural soils

    The safety is very important in facilities where radioactive wastes are stored. One of the necessary characteristics of the site where these wastes will be disposed is the soil permeability, since a waterproof terrain avoids the diffusion and radionuclide transport in the leakages case. The objective of this work is to study the adsorption kinetics of 201Tl and the migration of 99mTc in natural soil samples. The adsorption kinetics was determined starting from the obtaining of the retention coefficient of the thallium (static method) at different contact times. The technetium diffusion was studied by means of the dynamic method with different soil particles sizes. The results showed that the thallium is totally adsorbed starting from 20 h of contact among this and the mean. On the other hand, the technetium is very mobile in the soil, since it was possible to extract the majority of the tracer with little solvent. Also, it was found that for each soil gram the double water will be needed to leach the technetium almost in its entirety. Moreover, influence exists of the particle size in the migration velocity from the radiotracer to the most mobile being in major sizes than 2 mm that in minor size. (Author)

  15. Development of [{sup 201}Tl](III)-DTPA-human polyclonal antibody complex for inflammation detection

    Jalilian, A.R.; Kamali-Dehghan, M.; Kamrani, Y.Y. [Nuclear Research Center for Agriculture and Medicine, Karaj (Iran). Cyclotron and Nuclear Medicine Dept.; Khorrami, A.; Tavakoli, M.B. [Medical Sciences Univ. of Isfahan (Iran). Medical Physics and Engineering Dept.

    2007-07-01

    Thallium-201 (T{sub 1/2}=3.04 d) in Tl{sup +} form was converted to Tl{sup 3+} cation in presence of O{sub 3} in 6 M HCl controlled by RTLC/gel electrophoresis methods and used in the labeling of human polyclonal antibody (HIgG) after conjugation with freshly prepared cyclic DTPA-dianhydride. The best results of the conjugation were obtained by the addition of 1 mL of a HIgG pharmaceutical solution (5 mg/ml, in phosphate buffer, pH=7) to a glass tube pre-coated with DTPA-dianhydride (0.01 mg) at 25 C with continuous mild stirring for 30 min. The final isotonic [{sup 201}Tl](III)-DTPA-HIgG complex was checked by radio-TLC using several solvent systems to ensure the formation of only one species followed by filtration through a 0.22 {mu} filter (specific activity= 33.7 TBq/mM, radiochemical purity >95%). Preliminary bio-distribution studies in normal and inflammation-bearing rats were performed. The target/skin and target/blood ratios were 4 and 6 after 28 h respectively, showing the selectivity of the radiopharmaceutical for the inflammatory lesions. (orig.)

  16. Repeatability and reproducibility of phase analysis of gated single-photon emission computed tomography myocardial perfusion imaging used to quantify cardiac dyssynchrony

    Trimble, Mark A.; Velazquez, Eric J.; Adams, George L.; Honeycutt, Emily F.; Pagnanelli, Robert A.; Barnhart, Huiman X.; Chen, Ji; Iskandrian, Ami E.; Garcia, Ernest V.; Borges-Neto, Salvador

    2010-01-01

    Background A novel method to quantify dyssynchrony has been developed using phase analysis of gated single-photon emission computed tomography perfusion imaging. We report on the effect of variability in image reconstruction on the phase analysis results (repeatability) and on the interobserver and intraobserver reproducibility of the technique. Methods Phase standard deviation (SD) and bandwidth are phase indices that quantify dyssynchrony. To evaluate repeatability, raw data sets were processed twice in 50 patients with left ventricular dysfunction and 50 normal controls. To determine the optimal processing method, two replicated phase analysis results were obtained using automated and manual base parameter placement. Reproducibility of the phase analysis was determined using the data from 20 patients. Results In normal controls, manual base parameter placement improves repeatability of the phase analysis as measured by the mean absolute difference between two reads for phase SD (12.0° vs. 1.2°, P< 0.0001) and bandwidth (33.7° vs. 3.6°, P< 0.0001). Repeatability is better for normal controls than for patients with left ventricular dysfunction for phase SD (1.2° vs. 6.0°, P < 0.0001) and bandwidth (3.6° vs. 26.5°, P < 0.0001). Reproducibility of the phase analysis is high as measured by the intraclass correlation coefficients for phase SD and bandwidth of 0.99 and 0.99 for the interobserver comparisons and 1.00 and 1.00 for the intraobserver comparisons. Conclusion A novel method to quantify dyssynchrony has been developed using gated single-photon emission computed tomography perfusion imaging. Manual base parameter placement reduces the effect that variability in image reconstruction has on phase analysis. A high degree of reproducibility of phase analysis is observed. PMID:18317303

  17. A higher prevalence of abnormal regional cerebral blood flow in patients with syndrome X and abnormal myocardial perfusion

    To test the hypothesis that syndrome X is a systemic vascular disorder, technetium-99m ethyl cysteinate dimer (Tc-99m ECD) brain single photon emission computed tomography (SPECT) was used to detect abnormal regional cerebral blood flow (rCBF) in 30 patients with syndrome X. These patients were separated into group 1, 20 patients with definite myocardial perfusion defects diagnosed by thallium-201 (Tl-201) myocardial perfusion SPECT; and group 2, 10 patients without any myocardial perfusion defects. Tc-99m ECD brain SPECT demonstrated hypoperfusion brain lesions in 95% (19/20) and 20% (2/10) of patients in groups 1 and 2, respectively. This difference in the cidence between the two groups was significant. In group 1 and 2 patients, parietal lobes were the most common hypoperfusion areas, while the cerebellum was the least common hypoperfusion area of the brain. Syndrome X is a systemic vascular disorder with a high incidence of hypoperfusion lesions of the brain based on the findings of Tc-99m ECD brain SPECT, and is usually coincident with myocardial defects based on the Tl-201 myocardial perfusion SPECT findings. (author)

  18. Serial changes in myocardial perfusion and function after successful percutaneous transluminal coronary angioplasty, examined by stress thallium-201 myocardial scintigraphic and stress radionuclide ventriculographic studies

    In order to study the early and late effects of percutaneous transluminal coronary angioplasty (PTCA), 201Tl myocardial perfusion scintigraphy and exercise 99mTc ventriculography were performed in 25 patients who successfully received PTCA. Before PTCA, reduced myocardial perfusion on stress 201Tl image was observed in all 25 patients, while abnormal regional wall motion during exercise was seen in 22 cases. On stress 201Tl images, reduced myocardial perfusion was demonstrated in 11 cases at 3-7 days after PTCA, but in none at 3 months after the procedure. On the other hand, abnormal exercise regional wall motion was not observed in any case after successful PTCA even in the early phase. When the patients were divided into two groups according to the presence or absence of perfusion abnormalities on stress 201Tl images in the early post-PTCA phase, no difference was seen in clinical and coronary angiographic findings, exercise tolerance, 201Tl uptake score, wall motion score or left ventricular ejection fraction before the procedure. Thus, abnormal myocardial perfusion without impairment of regional left ventricular wall motion is frequently seen in the early post-PTCA phase. But this finding does not necessarily indicate associated myocardial ischemia. (author)

  19. Prediction of Changes in Left Ventricular Ejection Fraction after Off-Pump Coronary Artery Bypass Grafting Surgery by Myocardial Perfusion Single-Photon Emission Computed Tomography

    Maryam Mirzaie

    2015-09-01

    Full Text Available Introduction: Left ventricular ejection fraction (LVEF is considered to be the single most important prognostic factor in patients with previous myocardial infarction. LVEF is not improved in all patients after coronary artery bypass grafting (CABG. This study aimed to assess the possibility of prediction of LVEF changes after CABG using myocardial perfusion gated signle photon emission computed tomography (GSPECT. Materials and Methods: Overall, 48 patients with mean LVEF of 30.2% (±4.7 underwent Echocardiography and GSPECT after injection of Tc-99m-MIBI at rest. Myocardial uptake was evaluated in 17 myocardial segments and was compared with age and gender matched normal data pool. The risks and benefits of CABG were explained to the patients and 16 cases (15 male and 1 female with the mean age of 61.1 years (±10.8 accepted to undergo off-pump CABG. All the patients were followed-up for at least six months and echocardiography and GSPECT were repeated at the end of follow up. Results: The mean LVEF was increased from of 31.1% (±3.5 to 34.5% (±3.6 after surgery (P

  20. Single photons on demand

    Quantum cryptography and information processing are set to benefit from developments in novel light sources that can emit photons one by one. Quantum mechanics has gained a reputation for making counter-intuitive predictions. But we rarely get the chance to witness these effects directly because, being humans, we are simply too big. Take light, for example. The light sources that are familiar to us, such as those used in lighting and imaging or in CD and DVD players, are so huge that they emit billions and billions of photons. But what if there was a light source that emitted just one photon at a time? Over the past few years, new types of light source that are able to emit photons one by one have been emerging from laboratories around the world. Pulses of light composed of a single photon correspond to power flows in the femtowatt range - a million billion times less than that of a table lamp. The driving force behind the development of these single-photon sources is a range of novel applications that take advantage of the quantum nature of light. Quantum states of superposed and entangled photons could lead the way to guaranteed-secure communication, to information processing with unprecedented speed and efficiency, and to new schemes for quantum teleportation. (U.K.)

  1. Duke treadmill score (DTS) and gated single photon emission computed tomography-myocardial perfusion imaging (SPECT-MPI) in chest pain patient initial experience

    Background: Risk stratification of the patient with suspected or known coronary artery disease(CAD)by means of non-invasive testing are highly relevant in clinical cardiology for the selection of patient who require further diagnostic or therapeutic investigation. Aim: To predict severity of myocardial ischaemia by exercise tolerance test (ETT) determined duke treadmill score (DTS) and myocardial perfusion study. Material and methods: A total of 108 (92-men) patients presenting with Canadian cardiovascular society (CCS) class Mil severity of chest pain, mean age 49.88+8.44 yrs, were studied during October 2002-march 2003. All patient underwent ETT and SPECT-MPI scan using Tc-99m-tetrofosmin in one-day stress and rest protocol. Coronary angiogram (CAG) was done within six months of the perfusion study. After performing ETT, patients were categorized by DTS, myocardial perfusion studies were also stratified according to severity of perfusion defect. The angiographic findings (significant>50% stenosis) and perfusion defects in MPI were compared with the severity of DTS. Result: In high DTS group 91.66% patients had perfusion defect, whereas in intermediate and low risk group it was 60% and 40.90% respectively. In high DTS group 91.66% of patient had angiographically proven CAD, 58.33% of them had triple vessel disease (TVD) while in intermediate and low risk group angiographically proven CAD were 65% and 22.27% of whom TVD only in 15% and 0% respectively. Conclusion: The results of ETT using DTS score satisfactorily correlate with SPECT-MPI scanning in high DTS subsets of patients .So it is suggested that patient of high risk DTS could undergo CAG for further evaluation without radio-nuclide perfusion study. Intermediate and low risk needs myocardial perfusion imaging study to guide for further evaluation. (authors)

  2. Evaluation of coronary artery disease using myocardial thallium-201 imaging with single photon emission computed tomography during adenosine induced coronary vasodilation

    Adenosine-loaded Tl-201 myocardial SPECT was performed in consecutive 55 patients with suspected ischemic heart disease. Among these patients, 22 had cuncurrently exercise Tl-201 myocardial SPECT imaging for comparison. Adenosine was intravenously injected at a dose of 0.14 mg/kg/min continuously for 6 min, and 3 min after the stard of injection Tl-201 was injected via the different vein. Myocardial SPECT images were acquired at 5 min and 3 hr after the completion of intravenous injection of adenosine. Perfusion defect and the presence or absence of redistribution (RD) were visually interpreted from the short- and long-axial tomograms. Relative Tl-201 regional uptake ratios were quantitatively determined. Decreased systolic arterial pressure, increased heart rate, and slightly increased rate-pressure product were observed with adenosine injection. Chest pain (13 patients), head-ache (7), ST depression (17), and A-V block II were also seen; however, these symptoms rapidly disappeared with the withdrawal of adenosine. The findings by adenosine loading were concordent with those by exercise loading (91% for perfusion defect and 86% for presence or absence of RD). According to segments, both loading tests were concordent in 90% for persusion and 89% for RD. Both adenosine- and exercise-loaded imagings correlated well with regional Tl uptake by segements, the lowest value of Tl-201 defect, and extent score of Tl-201 defect. Adenosine-loaded imaging had a sensitivity of 100%, a specificity of 88%, and an accuracy of 97% for detecting parenchymal coronary lesions in evaluable 39 patients. In evaluable 22 patients, the sensitivity, specificity, and accuracy were 100%, 83%, and 95% for adenosine-loaded imaging and 88%, 83%, and 86% for exercise-loaded imaging. Thus, adenosine-loaded Tl-201 myocardial SPECT may be a safety and useful method for diagnosing ischemic heart disease. (N.K.)

  3. Factors affecting accuracy of ventricular volume and ejection fraction measured by gated Tl-201 myocardial perfusion single photon emission computed tomography

    Systemic errors in the gated single photon emission computed tomography (SPECT) measurement of left ventricular (LV) end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) may occur. We evaluated whether patient-related factors affected the accuracy of EDV, ESV, and EF measured by electrocardiogram-gated Tl-201 SPECT. A total of 518 patients without perfusion defects on Tl-201 SPECT or coronary artery disease were studied. EDV, ESV, and EF were measured from echocardiography and adenosine stress/redistribution gated Tl-201 SPECT using commercially available software packages (QGS and 4D-MSPECT). We identified factors affecting the accuracy of gated SPECT via multiple linear regression analysis of the differences between echocardiography and gated SPECT. Gated SPECT analyzed with QGS underestimated EDV and ESV, and overestimated EF, but 4D-MSPECT overestimated all those values (p<0.001). Independent variables that increased the difference in EDV between echocardiography and gated SPECT were decreasing LV end-diastolic wall thickness, decreasing body surface area, female sex and increasing EDV (p< 0.001). Those for ESV were decreasing LV end-systolic wall thickness, female sex, and decreasing ESV (p<0.001). Increasing end-systolic wall thickness, male sex and decreasing age were independent determinants associated with an increased difference in EF (p< 0.001). Adenosine stress SPECT showed significantly higher EDV and ESV values and a lower EF than did redistribution SPECT (p< 0.001). In determination of EF, QGS demonstrated a smaller bias than did 4D-MSPECT. However, in men with LV hypertrophy, 4D-MSPECT was superior to QGS. Systemic error by gated Tl-201 SPECT is determined by individual patient-characteristics

  4. Prognostic value of myocardial perfusion single photon emission computed tomography for major adverse cardiac cerebrovascular and renal events in patients with chronic kidney disease: results from first year of follow-up of the Gunma-CKD SPECT multicenter study

    Patients with chronic kidney disease (CKD) have an increased risk of adverse cardio-cerebrovascular events. We examined whether stress myocardial perfusion single photon emission computed tomography (SPECT) provides reliable prognostic markers for these patients. In this multicenter, prospective cohort trial from the Gunma-CKD SPECT study protocol, patients with CKD [estimated glomerular filtration rate (eGFR) < 60 min/ml per 1.73 m2] undergoing stress 99mTc-tetrofosmin SPECT for suspected or possible ischemic heart disease were initially followed for 1 year, with the following study endpoints: primary, the occurrence of cardiac deaths (CDs), and secondary, major adverse cardiac, cerebrovascular, and renal events (MACCREs). The summed stress score (SSS), summed rest score, and summed difference score (SDS) were estimated with the standard 17-segment, 5-point scoring model. Left ventricular end-diastolic volume, end-systolic volume (ESV), and ejection fraction were measured using electrocardiogram-gated SPECT. During the first year of follow-up, 69 of 299 patients experienced MACCREs (CD, n = 7; non-fatal myocardial infarction, n = 3; hospitalization for heart failure, n = 13; cerebrovascular accident, n = 1; need for revascularization, n = 38; and renal failure, i.e., hemodialysis initiation, n = 7). ESV and SSS were associated with CDs (p < 0.05), and eGFR and SDS were associated with MACCREs (p < 0.05), in multivariate logistic analysis. Patients with high ESV and high SSS had a significantly higher CD rate during the first year than the other CKD patient subgroups (p < 0.05). Patients with low eGFR and high SDS had a significantly higher MACCRE rate than the other subgroups (p < 0.05). Myocardial perfusion SPECT can provide reliable prognostic markers for patients with CKD. (orig.)

  5. Prognostic value of myocardial perfusion single photon emission computed tomography for major adverse cardiac cerebrovascular and renal events in patients with chronic kidney disease: results from first year of follow-up of the Gunma-CKD SPECT multicenter study

    Kasama, Shu [Gunma University Graduate School of Medicine, Department of Medicine and Biological Science (Cardiovascular Medicine), Maebashi, Gunma (Japan); Cardiovascular Hospital of Central Japan (Kitakanto Cardiovascular Hospital), Department of Cardiovascular Medicine, Gunma (Japan); Toyama, Takuji [Department of Cardiovascular Medicine, Gunma Prefectural Cardiovascular Center, Maebashi (Japan); Sato, Makito [Gunma University Graduate School of Medicine, Department of Medicine and Biological Science (Cardiovascular Medicine), Maebashi, Gunma (Japan); Tatebayashi Kosei Hospital, Department of Internal Medicine, Gunma (Japan); Sano, Hirokazu [Gunma University Graduate School of Medicine, Department of Medicine and Biological Science (Cardiovascular Medicine), Maebashi, Gunma (Japan); Isesaki Municipal Hospital, Department of Cardiovascular Medicine, Isesaki (Japan); Ueda, Tetsuya [Fujioka General Hospital, Division of Cardiology, Fujioka (Japan); Sasaki, Toyoshi [Takasaki General Medical Center, Division of Cardiology, Takasaki (Japan); Nakahara, Takehiro; Kurabayashi, Masahiko [Gunma University Graduate School of Medicine, Department of Medicine and Biological Science (Cardiovascular Medicine), Maebashi, Gunma (Japan); Higuchi, Tetsuya; Tsushima, Yoshito [Gunma University Graduate School of Medicine, Department of Diagnostic Radiology and Nuclear Medicine, Maebashi (Japan)

    2016-02-15

    Patients with chronic kidney disease (CKD) have an increased risk of adverse cardio-cerebrovascular events. We examined whether stress myocardial perfusion single photon emission computed tomography (SPECT) provides reliable prognostic markers for these patients. In this multicenter, prospective cohort trial from the Gunma-CKD SPECT study protocol, patients with CKD [estimated glomerular filtration rate (eGFR) < 60 min/ml per 1.73 m{sup 2}] undergoing stress {sup 99m}Tc-tetrofosmin SPECT for suspected or possible ischemic heart disease were initially followed for 1 year, with the following study endpoints: primary, the occurrence of cardiac deaths (CDs), and secondary, major adverse cardiac, cerebrovascular, and renal events (MACCREs). The summed stress score (SSS), summed rest score, and summed difference score (SDS) were estimated with the standard 17-segment, 5-point scoring model. Left ventricular end-diastolic volume, end-systolic volume (ESV), and ejection fraction were measured using electrocardiogram-gated SPECT. During the first year of follow-up, 69 of 299 patients experienced MACCREs (CD, n = 7; non-fatal myocardial infarction, n = 3; hospitalization for heart failure, n = 13; cerebrovascular accident, n = 1; need for revascularization, n = 38; and renal failure, i.e., hemodialysis initiation, n = 7). ESV and SSS were associated with CDs (p < 0.05), and eGFR and SDS were associated with MACCREs (p < 0.05), in multivariate logistic analysis. Patients with high ESV and high SSS had a significantly higher CD rate during the first year than the other CKD patient subgroups (p < 0.05). Patients with low eGFR and high SDS had a significantly higher MACCRE rate than the other subgroups (p < 0.05). Myocardial perfusion SPECT can provide reliable prognostic markers for patients with CKD. (orig.)

  6. Impact of intracoronary injection of mononuclear bone marrow cells in acute myocardial infarction on left ventricular perfusion and function: a 6-month follow-up gated {sup 99m}Tc-MIBI single-photon emission computed tomography study

    Lipiec, Piotr [Medical University of Lodz, 2nd Department of Cardiology, Lodz (Poland); Medical University of Lodz, 2nd Department of Cardiology, Bieganski Hospital, Lodz (Poland); Krzeminska-Pakula, Maria; Plewka, Michal; Kasprzak, Jaroslaw D. [Medical University of Lodz, 2nd Department of Cardiology, Lodz (Poland); Kusmierek, Jacek; Plachcinska, Anna; Szuminski, Remigiusz [Medical University of Lodz, Department of Nuclear Medicine, Lodz (Poland); Robak, Tadeusz; Korycka, Anna [Medical University of Lodz, Department of Hematology, Lodz (Poland)

    2009-04-15

    We investigated the impact of intracoronary injection of autologous mononuclear bone marrow cells (BMC) in patients with acute ST elevation myocardial infarction (STEMI) on left ventricular volumes, global and regional systolic function and myocardial perfusion. The study included 39 patients with first anterior STEMI treated successfully with primary percutaneous coronary intervention. They were randomly assigned to the treatment group or the control group in a 2:1 ratio. The patients underwent baseline gated single-photon emission computed tomography (G-SPECT) 3-10 days after STEMI with quantitative and qualitative analysis of left ventricular perfusion and systolic function. On the following day, patients from the BMC treatment group were subjected to bone marrow aspiration, mononuclear BMC isolation and intracoronary injection. No placebo procedure was performed in the control group. G-SPECT was repeated 6 months after STEMI. Baseline and follow-up G-SPECT studies were available for 36 patients. At 6 months in the BMC group we observed a significantly enhanced improvement in the mean extent of the perfusion defect, the left ventricular perfusion score index, the infarct area perfusion score and the infarct area wall motion score index compared to the control group (p=0.01-0.04). However, the changes in left ventricular volume, ejection fraction and the left ventricular wall motion score index as well as the relative changes in the infarct area wall motion score index did not differ significantly between the groups. Intracoronary injection of autologous mononuclear BMC in patients with STEMI improves myocardial perfusion at 6 months. The benefit in infarct area systolic function is less pronounced and there is no apparent improvement of global left ventricular systolic function. (orig.)

  7. Comparison between 360 and 180 data sampling in thallium-201 rest-redistribution single-photon emission tomography to predict functional recovery after revascularization

    Bax, J.J. [Department of Cardiology, Free University Hospital, Amsterdam (Netherlands); Visser, F.C. [Department of Cardiology, Free University Hospital, Amsterdam (Netherlands); Lingen, A. van [Department of Nuclear Medicine, Free University Hospital, Amsterdam (Netherlands); Sloof, G.W. [Department of Nuclear Medicine, Free University Hospital, Amsterdam (Netherlands); Cornel, J.H. [Department of Cardiology, Medical Center, Alkmaar (Netherlands); Visser, C.A. [Department of Cardiology, Free University Hospital, Amsterdam (Netherlands)

    1997-05-01

    The aim of this study was to perform a direct comparison between 180 and 360 data sampling in cardiac Tl-201 SPET to detect viable myocardium in patients undergoing revascularization; in order to allow optimal detection of viability a rest-redistribution protocol was used. The {sup 201}Tl results were compared with improvement of regional wall motion abnormalities after the revascularization, which was considered as the ``gold standard`` for myocardial viability. Thirty-two patients, scheduled for revascularization, underwent rest-redistribution {sup 201}Tl SPET, using a 360 arc. Raw data along a 180 arc (45 RAO to LPO) were selected from the original 360 data sets (both early an late {sup 201}Tl images). All SPET data were analysed semiquantitatively using circumferential profiles of the short-axis images; the data were displayed in polar maps. Criteria for viability included percentage {sup 201}Tl redistribution and percentage {sup 201}Tl activity on the late image. Regional wall motion was assessed with two-dimensional echocardiography before and 3 months after revascularization. The sensitivities of 360 and 180 imaging for the prediction of functional recovery were 82% and 89%, respectively, whereas the specificities were 51% and 55%, respectively. The diagnostic accuracy of 360 imaging was 62% and that of 180 imaging 67%. This study shows that 360 and 180 imaging have comparable diagnostic accuracy in the prediction of functional recovery after revascularization. With the newer dual-head gamma camera systems with each detector opposing each other, 360 imaging may be preferred. (orig./VHE). With 4 figs., 4 tabs.

  8. Differences between accumulation of 99mTc-MIBI and 201Tl-Thallous Chloride in tumour cells: Role of P-glycoprotein

    Both 99mTc-MIBI and 201Tl have been used for tumour imaging. It has recently been reported that 99mTc-MIBI is a substrate for P-glycoprotein (Pgp), a membrane pump which mediates multidrug resistance. It has been evaluated the role of Pgp in the cellular accumulation of 201TI by using sensitive and resistant strains of Chinese hamster ovary (CHO) fibroblasts (AuxB1 and CHRC5, respectively) grown in suspension culture. 201Tl accumulation was the same in sensitive and resistant cells, whereas 99mTc-MIBI accumulation was much lower in resistant cells than in sensitive ones. Down-modulation of Pgp with 100 μM verapamil did not alter cellular accumulation of 201Tl while it significantly increased 99mTc-MIBI accumulation in both types of cell. Similarly, 10 μM verapamil did not affect the rate of washout of 201Tl from preloaded cells, while 99mTc-MIBI washout was greatly reduced in the presence of verapamil. These results suggest that 201Tl will accumulate in both sensitive and resistant tumour cells, whereas 99mTc-MIBI will be extruded from resistant cells and therefore may be less useful for tumour detection when the tumour cells express high Pgp levels

  9. Intracellular binding site kinetics of 201 Tl binding compared to β-adrenergic analog receptors in dog myocardium

    It has been demonstrated with the multiple indicator dilution technique (MID) in an isolated dog heart preparation, that the permeation of thallium ions across the sarcolemma is about ten times larger compared to potassium ions (cellular permeability surface area product PSM 8.90 +- 4.60 vs. 0.65 +- 0.46 ml/min gsup(-1)). Similarly, the intracellular (IC) distribution space of Tlsup(+) is larger compared to that of Ksup(+). These properties may explain in part the rapid and large extraction of Tl in the myocardium. To explain the slow washout rate of Tl from the myocardium (T 1/2>600 sec determined with an on-line residue detection) we proposed a temporary binding of Tl to an IC protein. In experiments the permeation properties of 201 Tl were compared to 125 I-cyanopinodolol (I-CP) and 131 I metabenzylquanidin (I-MBG) by means of MID. The latter two substances act at the β-adrenergic receptor site. Both substances have a lower capillary permeability surface area product PSC of 0.43 +- 0.37 ml/min gsup(-1) compared to that of 201 Tl (1.37 +- 0.49 ml/min gsup(-1)). I-CP and I-MBG are sequestered extracellularly in contrast to Tl, which permeates intracellularly. However, the relation between time and instantaneous extraction during a single bolus passage of 201 Tl is very comparable to that of those receptor substances suggesting also a receptor-type kinetics for Tl with intracellular binding which may elucidate its prolonged washout. (Author)

  10. Myocardial technetium-99m sestamibi single-photon emission tomography as a prognostic tool in coronary artery disease: multivariate analysis in a long-term prospective study

    A prospective study was started in 1988 and at present 176 consecutive, and thus unselected, patients have been enrolled. All of them have been submitted to stress-rest MIBI SPET for the diagnosis or evaluation of CAD; 147 patients (121 males and 26 females, aged 53±9 years) have completed a surveillance period of at least 36 months following the scintigraphic study (range 36-60 months, mean 43). Sixty-one patients had a documented previous myocardial infarction. The mean pre-test likelihood of CAD was 44% in the patients without prior infarction. The main anamnestic, clinical, EKG and scintigraphic findings were evaluated and statistically correlated with the incidence of ensuing cardiac events using both univariate (chi-square test) and multivariate analysis (logistic regression model). Twenty-nine patients suffered from a cardiac event during the follow-up period (i.e. three cardiac deaths, six myocardial infarctions and 20 cases of unstable angina). Statistical multivariate analysis identified MIBI scan as the only highly significant and independent prognostic predictor. In detail, the most important scintigraphic parameters were the presence of a reversible defect and the extension of the stress perfusion defect. The presence of typical angina proved to be a slightly significant predictor, while no other examined parameter showed a significant correlation with a bad prognosis. In conclusion, MIBI SPET can be considered a useful tool in the risk stratification of CAD patients. (orig.). With 3 tabs

  11. Effect of imaging time on post stress left ventricular ejection fraction and volume measures by gated myocardial perfusion single photon emission computed tomography

    Bekir Taşdemir

    2010-12-01

    Full Text Available Objectives: Post-stress left ventricular ejection fraction (LVEF and LV volumes have incremental value in predicting cardiac death (CD in patients with coronary artery disease. In this study, we aimed to investigate the effect of imaging time after exercise on post-stress LVEF, end-diastolic volume (EDV and end-systolic volume (ESV calculated by cardiac quantification software program called Quantitative Gated SPECT (QGS-Cedars-Sinai.Materials and methods: This study was consisted of 36 patient referred to Nuclear Medicine Department from Cardiology Clinics because of chest pain in ‘Elazig Research and Training Hospital’ in 2008-2009. In all patients, ECG Gated (8-bin frame mode myocardial perfusion SPECT scintigraphy was performed 20 and 40 min later following 99mTc-Mibi injection during exercise. By means of the cardiac quantification software program called Quantitative Gated SPECT (QGS-Cedars-Sinai; LVEF, EDV and ESV were calculated. LVEF, EDV and ESV values obtained from initial and second acquisition were compared statistically.Results: There was no statistically significant difference between post-stress LVEF, EDV and ESV measures of initial and second acquisition (p>0.05.Conclusion: Left ventricular functional parameters after exercise are important for assess prognosis in patients with CAD. Post-stress LVEF, EDV and ESV measured on gated myocardial perfusion SPECT images within 20-40 min after completion of exercise give reproducible information. J Clin Exp Invest 2010; 1(3: 177-181

  12. Evaluation of the perfusion and contractile function of the myocardium using Karhunen-Loeve analysis in myocardial gated single photon emission computerized tomography

    Goal: we evaluated the diagnostic performance of the Karhunen-Loeve transform applied to myocardial gated SPECT. The previous studies showed that K.L.T. images characterize myocardial perfusion (K.L.0) and contractile function (K.L.1). Method and material: 99 mTc-g SPECT studies were performed in 101 patients (121 acquisitions) with suspected or known coronary artery disease. The images were evaluated using a five-point scoring system dividing the left ventricle into 11 segments. We compared the scores obtained by this semi-quantitative visual analysis of g SPECT and K.L.T. images. Results and discussion: the agreement for perfusion and thickening scores was 94 and 95% respectively. Quantitative evaluation of K.L.0 and K.L.1 images by univariate and multivariate analysis was performed in the left ventricular R.O.I.. Discriminant analysis characterized the acquisitions as normal or pathologic with a sensitivity of 95% and a specificity of 96% and positive and negative predictive values of 96 and 95%. These selection criteria were tested prospectively in 52 patients with similar results. K.L.T. generates a synthesis of left ventricular perfusion and kinetics. It facilitates discrimination between normal and pathological acquisitions with high predictive values. (authors)

  13. Single-photon quadratic optomechanics

    Jie-Qiao Liao; Franco Nori

    2013-01-01

    We present exact analytical solutions to study the coherent interaction between a single photon and the mechanical motion of a membrane in quadratic optomechanics. We consider single-photon emission and scattering when the photon is initially inside the cavity and in the fields outside the cavity, respectively. Using our solutions, we calculate the single-photon emission and scattering spectra, and find relations between the spectral features and the system's inherent parameters, such as: the...

  14. Nuclear cardiological investigations in patients classified as physically disabled following myocardial infarction

    110 patients classified as physically disabled as a consequence of myocardial infarction were reinvestigated by means of nuclear cardiological methods. Resting 201Tl perfusion scintigraphy showed a normal distribution of radioactivity, while radionuclide ventriculography revealed a normal left ventricular ejection fraction and a normokinetic left ventricle in 20 patients. The investigation of a further 19 patients demonstrated only minimal pathological changes. The results in 34 patients revealed severe myocardial damage, and in a further 19 cases the development of left ventricular aneurysm. The results clearly show the value of 201Tl scintigraphy and radionuclide ventriculography in assessments of the degree of physical disability after myocardial infarction. (author) 15 refs.; 3 tabs

  15. Assessment of resistance to paclitaxel of murine tumors by 99mTc-MIBI/201Tl dual-radionuclide imaging

    This study investigated P-glycoprotein (Pgp) expression by murine tumors with and without resistance to paclitaxel and the role of 99mTc-2-methoxyisobutylisonitrile (MIBI)/201Tl imaging in predicting the effect of paclitaxel. Antitumor effect of paclitaxel and biodistribution of the radiopharmaceuticals were evaluated in mice bearing four tumor types. Pgp expression did not correlate with the antitumor efficacy of paclitaxel. Although the absolute uptake of 99mTc-MIBI did not correlate with Pgp expression, 99mTc-MIBI could predict paclitaxel sensitivity by its higher uptake

  16. A two-dimensional extrapolation for the standardization of 201Tl by the 4πβ-τ coincidence method

    201TL has been standardized by 4πβ-τ coincidence measurements using one- and two-dimensional extrapolation. An analysis of the various contributions to the count rate of the β channel is made and it is shown that due to low-energy conversion electrons two-dimensional extrapolation is preferable. Several measurements have been performed under various conditions with a coincidence system consisting of a Ge detector or a NaI crystal for the detection of τ rays and a pressurized proportional counter for the detection of the x rays and Auger electrons from electron capture. (author)

  17. Two-dimensional extrapolation for the standardization of /sup 201/Tl by the 4. pi beta. -tau coincidence method

    Funck, E.

    1987-01-01

    /sup 201/TL has been standardized by 4..pi beta..-tau coincidence measurements using one- and two-dimensional extrapolation. An analysis of the various contributions to the count rate of the ..beta.. channel is made and it is shown that due to low-energy conversion electrons two-dimensional extrapolation is preferable. Several measurements have been performed under various conditions with a coincidence system consisting of a Ge detector or a NaI crystal for the detection of tau rays and a pressurized proportional counter for the detection of the x rays and Auger electrons from electron capture.

  18. Clinical significance of stress-induced ST segment changes in patients with previous myocardial infarction

    To explain the clinical significance of stress(st)-induced ST-segment (ST) changes postinfarction, 93 patients with previous myocardial infarction (MI) were performed st-201Tl myocardial single photon emission computed tomography (SPECT) and compared ST changes with SPECT, coronary arteriographic and left ventriculographic findings. 30 out of 93 cases (32%) had ST depression, 20 (21.5%) had ST elevation, 9 (10%) had both ST depression and elevation and remaining 34 (36.5 %) had no significant ST changes. In single vessel disease, ST depression were noted in 29% (12/42), while in multivessel disease, 53% (27/51). 35 out of 39 cases (90%) with ST depression had transient perfusion defect but no apparent relation was noted between location of ST depression on ECG and region of transient perfusion defect in SPECT. All of 28 cases with ST elevation were noted in anterior MI cases, and 26 out of these showed severe LV wall motion abnormality in contrast left ventriculography and broad anterior permanent defect in SPECT. Only 15 cases (54%) showed slight redistribution. Thus, we conclude that in patients with previous MI, st-induced ST depression seems to reflect myocardial ischemia and ST elevation possibly related abnormal LV wall motion. (author)

  19. Therapeutic effect of co-enzyme Q10 on idiopathic dilated cardiomyopathy: assessment by iodine-123 labelled 15-(p-iodophenyl)-3(R,S)-methylpentadecanoic acid myocardial single-photon emission tomography

    It has been reported that myocardial mitochondrial function can be improved by the administration of co-enzyme Q10 (CoQ10). Recently, iodine-123 labelled 15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) was developed for metabolic imaging using single-photon emission tomography (SPET). This study was conducted to determine whether the therapeutic effects of CoQ10 on idiopathic dilated cardiomyopathy can be evaluated by BMIPP myocardial SPET. Fifteen patients, comprising 14 men and one woman (mean age: 64±12 years), were examined. CoQ10 was administered at 30 mg/day for a period of 35.7±12.4 days. BMIPP myocardial SPET was carried out before and after CoQ10 treatment. The count ratio of the heart (H) to the upper mediastinum (M) (H/M ratio) was calculated using a region of interest method with anterior planar imaging. Representative short-axis tomograms were divided into 27 segments (three slices x nine segments). Each segmental score was analysed semiquantitatively using a four-point scoring system (normal=0, mild low uptake=1, severe low uptake=2, defect=3). The H/M ratio showed a significant improvement, from 2.39±0.39 to 2.54±0.47, after treatment (P<0.05). The BMIPP total defect score after CoQ10 treatment was significantly decreased to 10.1±4.3, compared to 13.9±4.5 without CoQ10 treatment (P<0.001). However, the percent fractional shortening measured using echocardiography was not significantly different before and after CoQ treatment (19.2±8.1 vs 19.7±7.1). BMIPP myocardial SPET was confirmed to be sensitive in evaluating the therapeutic effects of CoQ10 in patients with idiopathic dilated cardiomyopathy. This method is unique, since the therapeutic effects can be estimated from the perspective of metabolic SPET imaging. (orig.). With 5 figs., 1 tab

  20. Comparison of low-dose dobutamine stress echocardiography and single photon emission computed tomography and delayed contrast MRI in the diagnosis of myocardial viability: Meta-analysis

    Objective: To assess the diagnostic value of different imaging methods including low- dose dobutamine stress echocardiography, SPECT and contrast enhancement MRI with Meta-analysis in the diagnosis of myocardial viability. Methods: Articles published from 1998 to 2008 were searched in Cochrane library, Medline, Embase database, OVID database and CNKI for relevant English and Chinese articles. According to the criteria for diagnostic research published by Cochrane Method Group on screening and diagnostic tests, each article was critically screened and appraised, including the absolute numbers of true-positive, false-negative, tree-negative, and false-positive. Statistical analysis was performed employing Meta-test. Heterogeneity was tested, pooled weighted sensitivity and specificity and the corresponding 95% CI were calculated. Characteristic (SROC) curve was performed and the area under the curve was calculated. Finally, sensitivity analysis was performed. Results: Twenty-one of 438 retrieved articles were included, in which there were ten articles about Low-dose dobutamine stress echocardiography, and six articles about 99Tcm-MIBL/99Tcm-Tetrofosmin SPECT, and six articles about contrast enhancement MRI, and one of both 99Tcm-MIBL/99Tcm-tetrofosmin SPECT and contrast enhancement MRI. All groups had heterogeneity, and a random effects regression was developed. The pooled weighted sensitivity and specificity and area under SROC curve for low-dose dobutamine stress echocardiography to diagnose myocardial viability was 0.73(0.62-0.82)/0.82 (0.77-0.86) and 87.07% respectively. They were 0.82 (0.59-0.94)/ 0.77 (0.64-0.86) and 86.97% for 99Tcm-MIBI/99Tcm-Tetrofosmin SPECT respectively, while they were 0.94 (0.86-0.97)/0.75 (0.66-0.83) and 91.41% for contrast enhancement MRI respectively. Conclusion: As noninvasive testing technologies, low-dose dobutamine stress echocardiography and 99Tcm-MIBI/99Tcm-tetrofosmin SPECT and delayed contrast enhanced MRI allow the

  1. Experimental study of hypoxic preconditioning on 99Tcm-MIBI and 201Tl kinetics in cultured neonatal rat cardio-myocytes

    Objective: To study the effect of hypoxic preconditioning (HPC) on 99Tcm-MIBI and 201Tl kinetics in cultured neonatal rat cardio-myocytes. Methods: The protection of HPC was assayed on the model of hypoxia/reoxygenation (H/R) of cultured neonatal rat cardio-myocytes and the Trypan blue exclusion method was used to assess cell viability. Normal, hypoxic preconditioning and hypoxia/reoxygenation cardio-myocytes groups were studied. By measuring the diffused and released radioactivity of myocytes in different time intervals, the effect of HPC on 99Tcm-MIBI and 201Tl uptake and clearance kinetics in the myocytes was observed in various conditions. Results: Compared with H/R, the number of viable cells after HPC [(75.31 +- 3.45)% vs (55.50 +- 3.13)%, P 99Tcm-MIBI and 201Tl to a plateau level with a half-time of 12.8 min and 6.5 min, respectively. HPC caused a significant increase in uptake of 99Tcm-MIBI [normal control, (4852 +- 491) counts·min-1·mg-1 protein to HPC group, (6103 +- 170) counts·min-1·mg-1 protein; P 201Tl uptake [normal control, (3190 +- 183) counts·min-1·mg-1 protein to HPC group, (2120 +- 202) counts·min-1·mg-1 protein; P 99Tcm-MIBI and 201Tl were both retarded. Conclusions: These results suggested that the neonatal rat cardio-myocytes after HPC offered more capacity to tolerate the H/R damage and HPC could influence the 99Tcm-MIBI and 201Tl uptake and clearance

  2. Difference in {sup 201}TlCl accumulation mechanism in brain tumors. A comparison of their Na{sup +}-K{sup +} ATPase activities

    Sugo, Nobuo; Kuroki, Takao; Nemoto, Masaaki; Mito, Toshiaki; Seiki, Yoshikatsu; Shibata, Iekado [Toho Univ., Tokyo (Japan). Omori Hospital

    2000-07-01

    The accumulation levels of {sup 201}TlCl and Na{sup +} -K{sup +} ATPase activity in tumor tissue were compared among glioblastoma, benign glioma and meningioma to study the difference in the mechanism of {sup 201}TlCl accumulation. The subjects were 19 cases comprised of 6 glioblastoma, 2 oligodendroglioma, 1 fibrillary astrocytoma, 1 pilocytic astrocytoma and 9 meningioma. Preoperative {sup 201}TlCl SPECT was performed in all the cases, and Thallium Index (TL index) was calculated by a ratio of {sup 201}TlCl in the tumor area and the contralateral area. In addition, cell membrane was extracted from the tumor tissue collected intraoperatively to determine Na{sup +} -K{sup +} ATPase activity. No statistically significant difference in TL index was noted between the glioblastoma group (6.97{+-}2.67) and the meningioma group (5.87{+-}1.99). This fact showed that there was no difference in the accumulation level of {sup 201}TlCl between the two groups. On the other hand, the glioblastoma group indicated a higher value of Na{sup +} -K{sup +} ATPase activity (49.13{+-}43.76 {mu}mole/hour/mg protein) than the meningioma group (7.73{+-}13.84 {mu}mol/hour/mg protein) (p<0.05, t test). These results suggested the involvement of Na{sup +} -K{sup +} ATPase activity in {sup 201}TlCl accumulation in glioblastoma and the influences of other accumulation mechanism than Na{sup +} -K{sup +} ATPase activity such as the volume of intratumoral vascular bed in meningioma. (author)

  3. Standardization of 201Tl and 55Fe radionuclides in a 4 (PC)-NaI(Tl) coincidence system

    In the present work the procedure for the standardization of radionuclides using the 4π(PC)-NaI(Tl) coincidence system was developed. The radionuclides selected were 201Tl, used in nuclear medicine, and 55Fe primary standard source, used for x-ray spectrometers calibration. The 4π(PC)-NaI(Tl) is composed of a 4 proportional counter operated at 0.1MPa coupled to two NaI(Tl) crystals. The 201Tl decays by electron capture process followed by a prompt gamma-ray. The disintegration rate was determined by extrapolation technique using two methods: electronic discrimination and external absorbers. The radioactive sources were prepared in a 20 μg cm-2 thick Collodion film. The conventional electronic system was used. The observed events were registered by the TAC method. The 55Fe decays by electron capture process to the ground state of 55Mn, emitting x rays with around 6 keV. The standardization was obtained by the tracing method. This technique was applied using two radionuclides, which decay by electron capture process followed by a prompt gamma-ray, namely 51Cr and 54Mn, as tracers. Measurements with 1 and 2 aluminum foils, each 150 g cm-2 thick were carried out. The activity was obtained by extrapolation for zero thickness Al foil. The uncertainties were treated by means of matrix covariance methodology and takes into account all correlations involved. (author)

  4. 201-Tl production studies by 203-Tl(p,3n)201-Pb and 202-Hg(p,2n) nuclear reactions

    Birattari, C.; Bonardi, M.; Salomone, A. (Milan Univ. (Italy). Ist. di Fisica)

    Thallium 201 has been produced in the Milan university AVF cyclotron by a /sup 203/Tl(p,3n)/sup 201/Pb and /sup 202/Hg(p,2n) nuclear reactions. /sup 201/Tl//sup 201/Pb were separated radiochemically by the preparation of thallium as thallous iodide after complexation of the lead with EDTA. /sup 202/Hg and /sup 201/Tl were separated by washing the target and holder, to which the radiothallium adheres with 3HCl and adding NaOH. Quality control is by radiochromatography.

  5. Clinical study on myocardial imaging with β-methyl-p-(123I)-iodophenyl-pentadecanoic acid in patients with mitochondrial myopathy

    Myocardial imaging with β-methyl-p-(123I)-iodophenyl-pentadecanoic acid (123I-BMIPP), a new radiopharmaceutical designed to evaluate myocardial fatty acid metabolism, was performed in 7 patients with mitochondrial myopathy to detect their myocardial damages in comparison with 201Tl myocardial imaging. These patients were divided into 4 chronic progressive external ophthalmoplegia (CPEO) cases, 2 mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) cases and 1 myoclonus epilepsy with ragged-red fibers (MERRF). In visual assessment, we observed more myocardial segments with decreased uptake of 123I-BMIPP compared to 201Tl in MELAS cases than in CPEO cases. The mean myocardial uptake of 123I-BMIPP was higher than that of 201Tl in CPEO cases. On the other hand, in MELAS and MERRF cases, the mean myocardial uptake of 123I-BMIPP was lower than that of 201Tl. Abnormal findings suggesting myocardial damages were observed in echocardiogram and/or in electrocardiogram in MELAS and MERRF cases, while no such abnormal findings were observed in CPEO cases. Along with the previously reported experimental result that the impairment of rat myocardial mitochondria decreased myocardial uptake of 123I-BMIPP, these results suggest that 123I-BMIPP may be useful to detect myocardial damages in patients with mitochondrial myopathy. (author)

  6. Clinical study on myocardial imaging with. beta. -methyl-p-( sup 123 I)-iodophenyl-pentadecanoic acid in patients with mitochondrial myopathy

    Kihara, Koichi; Nakajo, Masayuki; Shono, Hirohisa (Kagoshima Univ. (Japan). Faculty of Medicine) (and others)

    1992-04-01

    Myocardial imaging with {beta}-methyl-p-({sup 123}I)-iodophenyl-pentadecanoic acid ({sup 123}I-BMIPP), a new radiopharmaceutical designed to evaluate myocardial fatty acid metabolism, was performed in 7 patients with mitochondrial myopathy to detect their myocardial damages in comparison with {sup 201}Tl myocardial imaging. These patients were divided into 4 chronic progressive external ophthalmoplegia (CPEO) cases, 2 mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) cases and 1 myoclonus epilepsy with ragged-red fibers (MERRF). In visual assessment, we observed more myocardial segments with decreased uptake of {sup 123}I-BMIPP compared to {sup 201}Tl in MELAS cases than in CPEO cases. The mean myocardial uptake of {sup 123}I-BMIPP was higher than that of {sup 201}Tl in CPEO cases. On the other hand, in MELAS and MERRF cases, the mean myocardial uptake of {sup 123}I-BMIPP was lower than that of {sup 201}Tl. Abnormal findings suggesting myocardial damages were observed in echocardiogram and/or in electrocardiogram in MELAS and MERRF cases, while no such abnormal findings were observed in CPEO cases. Along with the previously reported experimental result that the impairment of rat myocardial mitochondria decreased myocardial uptake of {sup 123}I-BMIPP, these results suggest that {sup 123}I-BMIPP may be useful to detect myocardial damages in patients with mitochondrial myopathy. (author)

  7. Thallium-201 stress-redistribution myocardial rotational tomography: development of criteria for visual interpretation

    Despite high sensitivity and specificity for overall detection of coronary artery disease (CAD), planar stress-redistribution thallium-201 (Tl-201) scintigraphy remains suboptimal in localizing disease, because of overlap of myocardial segments. Single photon emission computerized tomography (SPECT), by providing three-dimensional representation of myocardial Tl-201, offers promise for improved localization of CAD. In 50 consecutive patients (22 normal and 28 with CAD), who underwent SPECT stress-redistribution Tl-201 imaging, we systemically developed visual interpretive criteria for perfusion abnormality on SPECT. For overall detection of disease, the best criterion for abnormality was greater than or equal to 8 sectors of moderately decreased Tl-201 uptake. With this criterion, the true positive and true negative rates for overall detection of disease were 96% and 91%, respectively. The best criterion for significant defect in the anterior or posterior coronary circulation was greater than or equal to 3 sectors of moderately decreased Tl-201 uptake. With this criterion, the true positive and true negative rates for anterior circulation disease were 71% and 100%, respectively. With respect to posterior circulation disease, the true positive and true negative rates were 100% and 50%, respectively. Regarding identification of dual circulation disease, the true positive and true negative rates were 71% and 82%, respectively

  8. Single-photon decision maker

    Makoto Naruse; Martin Berthel; Aurélien Drezet; Serge Huant; Masashi Aono; Hirokazu Hori; Song-Ju Kim

    2015-01-01

    Decision making is critical in our daily lives and for society in general and is finding evermore practical applications in information and communication technologies. Herein, we demonstrate experimentally that single photons can be used to make decisions in uncertain, dynamically changing environments. Using a nitrogen-vacancy in a nanodiamond as a single-photon source, we demonstrate the decision-making capability by solving the multi-armed bandit problem. This capability is directly and im...

  9. Single-photon Sagnac interferometer

    Bertocchi, Guillaume; Alibart, Olivier; Ostrowsky, Daniel Barry; Tanzilli, Sébastien; Baldi, Pascal

    2006-01-01

    We present the first experimental demonstration of the optical Sagnac effect at the single-photon level. Using a high quality guided-wave heralded single- photon source at 1550 nm and a fibre optics setup, we obtain an interference pattern with net visibilities up to (99.2 $\\pm$ 0.4%). On the basis of this high visibility and the compactness of the setup, the interest of such a system for fibre optics gyroscope is discussed.

  10. Sympathetic reinnervation in cardiac transplants: {sup 123}I-MIBG and {sup 201}Tl/{sup 99m}Tc-MIBI scintigraphy

    Kim, J. H.; Oh, S. J.; Son, M. S.; Son, J. W.; Choi, I. S.; Shin, E. K.; Park, C. H. [Gachon Medical School, Gil Heart Cener, Inchon (Korea, Republic of)

    2000-07-01

    The purpose was to evaluate cardiac sympathetic reinnervation and hemodynamic changes after orthotopic heart transplantation (TPL). We performed 24 serial or followup cardiac 123I-MIBG imaging and rest 201Tl/99mTc-MIBI dipyridamole stress gated myocardial perfusion SPECT (g-MPS) in 15 patients (M:F=10:5;mean ages=34.5{+-}13.0 yr; idiopathic:rheumatic=14:1; one heart lung TPL)(10.80 {+-}11.88 (1-48) mo) after TPL 123I-MIBG imagings were performed in anterior position 15 minutes, 4 and 24 hours after i.v. injection of 148 MBq 123I MIBG. Image quantitation was based on the ratio of heart to mediastinal MIBG uptake (HMR) Compared to HMR on 15 min images (1.48 {+-} 0.28), neither four nor 24 hour delayed images (1.26 {+-} 0.23 vs. 1.06 {+-} 0.26: p<0.05, respectively, ANOVA) showed definite delayed localization of MIBG. 12 subjects with <13 (4.9 {+-}3.7) months after TPL had no visible 123I-MIBG uptake on early 15 min imaging however, 12 subjects with 13 to 48(28.6{+-}12.8) months had visible cardiac 123I-MIBG uptake (HMR: 1.65{+-}0.21 vs. 1.32{+-}0.26; p=0.002). One-year followup 123I-MIBG scintigraphy in nine pts showed significantly increased HMR(1.40{+-}0.31 to 1.61{+-}0.16, p<0.05) but a plateau was reached at HMR value of 2.0, which was still lower than 3.0 in normal controls. Plasma NE was increased according to I-123 MIBG myocardial uptake. Annual G-MPS detected an allograft atherosclerosis in one pt and showed progressive normalization of tachycardia and significant deterioration of LVEF and cardiac indices according to severity of rejection. To dipyridamole stress, transplant heats showed significant subnormal hemodynamic responses. Partial sympathetic late reinnervation can occur <1 year after TPL, and reached a plateau of two-third of normal value. G-MPS seems to be a useful screening test for the detection of allograft atherosclerosis and rejection.

  11. Assessment of myocardial viability by thallium-201 reinjection imaging with sublingual nitroglycerin

    Although thallium-201 (201Tl) reinjection imaging improves the detection of myocardial viability compared to standard 3-4 hr redistribution (RD) imaging, it still underestimates the extent of viable myocardium. We examined whether 201Tl reinjection SPECT with sublingual nitroglycerin (NTG) had a higher sensitivity for viability detection than reinjection alone. Eighty patients with coronary artery disease were studied, 38 of them with an old myocardial infarction. At the peak of exercise, 111 MBq of 201Tl was injected and the initial and the delayed SPECT images were obtained. Then, all patients were divided randomly into two groups, and in each group, SPECT data were obtained again after the injection of 37 MBq of 201Tl with (NTG(+) group) or without 0.6 mg of sublingual NTG (NTG(-) group). Among 50 segments showing fixed defects on the delayed image in the NTG(+) group, 21 (42%) were found to be reversible on the reinjection image, as compared to 16 of 51 (31%) in the NTG(-) group. Twenty-two of 44 (50%) segments showing incomplete RD were found to be reversible in the NTG(+) group, while 17 of 42 (41%) segments in the NTG(-) group. Moreover, the ratio of reversible segments seen in the reinjection images was significantly higher in the collateralized regions of the NTG(+) group than in those of the NTG(-) group (20/26 vs. 14/28, p201Tl reinjection SPECT with sublingual NTG improves the detection of ischemic but viable myocardium as compared to SPECT with reinjection alone. (author)

  12. Usefulness of thallium-201 myocardial scintigraphy during hyperventilation and accelerated exercise test in patients with vasospastic angina and nearly normal coronary artery

    The usefulness of thallium-201 (201Tl) myocardial scintigraphy was studied in 109 patients with vasospastic angina who had nearly normal coronary arteries (degree of stenosis 201Tl myocardial scintigraphy was compared between four groups, 34 patients performing graded bicycle ergometer exercise starting at a work load of 50 W with increments of 25 W every 3 min (Ergo(3) group), 14 patients performing hyperventilation for 5 min (HV(5) group), 31 patients performing bicycle ergometer exercise with increments of 25 W every 1 min after 5 min hyperventilation (HV(5)+Ergo(1) group), and 30 patients at rest (Rest group). The value of the visual redistribution rate on 201Tl myocardial scintigrams in the HV(5)+Ergo(l) group (65%) was higher than that in the patients of other groups (Ergo(3) 41%, HV(5) 43%, Rest 33%). However, there were no significant differences between the four groups. Stress 201Tl imaging after hyperventilation and accelerated exercise is useful to disclose ischemic evidence in about two thirds of patients with vasospastic angina and nearly normal coronary arteries, whereas about 40% of patients had visual redistribution on 201Tl myocardial scintigrams by performing standard procedures. (author)

  13. Kinetic analysis of 18F-fluorodihydrorotenone as a deposited myocardial flow tracer: Comparison to thallium-201.

    Marshall, Robert C.; Powers-Risius, Patricia; Reutter, Bryan W.; O' Neil, James P.; La Belle, Michael; Huesman, Ronald H.; VanBrocklin, Henry F.

    2004-03-01

    The goal of this investigation was to assess the accuracy of 18F-fluorodihydrorotenone (18F-FDHR) as a new deposited myocardial flow tracer and compare the results to those for 201Tl. Methods. The kinetics of these flow tracers were evaluated in 22 isolated, erythrocyte- and albumin-perfused rabbit hearts over a flow range encountered in patients. The two flow tracers plus a vascular reference tracer (131I-albumin) were introduced as a bolus through a port just above the aortic cannula. Myocardial extraction, retention, washout, and uptake parameters were computed from the venous outflow curves using the multiple indicator dilution technique and spectral analysis. Results. The mean initial extraction fractions of 18F-FDHR (0.85 +- 0.07) and 201Tl (0.87 +- 0.05) were not significantly different, although the initial extraction fraction for 18F-FDHR declined with flow (P < 0.0001), whereas the initial extraction fraction of 201Tl did not. Washout of 201Tl was faster (P < 0.001) and more affected by flow (P < 0.05) than 18F-FDHR washout. Except for initial extraction fraction, 18F-FDHR retention was greater (P < 0.001) and less affected by flow (P < 0.05) than 201Tl retention. Reflecting its superior retention, net uptake of 18F-FDHR was better correlated with flow than 201Tl uptake at both one and fifteen minutes after tracer introduction (P < 0.0001 for both comparisons). Conclusion. The superior correlation of 18F-FDHR uptake with flow indicates that it is a better flow tracer than 201Tl in the isolated rabbit heart. Compared to the other currently available positron-emitting flow tracers (82Rb, 13N-ammonia, and 15O-water), 18F-FDHR has the potential of providing excellent image resolution without the need for an on-site cyclotron.

  14. Single-photon decision maker

    Naruse, Makoto; Berthel, Martin; Drezet, Aurélien; Huant, Serge; Aono, Masashi; Hori, Hirokazu; Kim, Song-Ju

    2015-08-01

    Decision making is critical in our daily lives and for society in general and is finding evermore practical applications in information and communication technologies. Herein, we demonstrate experimentally that single photons can be used to make decisions in uncertain, dynamically changing environments. Using a nitrogen-vacancy in a nanodiamond as a single-photon source, we demonstrate the decision-making capability by solving the multi-armed bandit problem. This capability is directly and immediately associated with single-photon detection in the proposed architecture, leading to adequate and adaptive autonomous decision making. This study makes it possible to create systems that benefit from the quantum nature of light to perform practical and vital intelligent functions.

  15. Nonlinear interaction between single photons.

    Guerreiro, T; Martin, A; Sanguinetti, B; Pelc, J S; Langrock, C; Fejer, M M; Gisin, N; Zbinden, H; Sangouard, N; Thew, R T

    2014-10-24

    Harnessing nonlinearities strong enough to allow single photons to interact with one another is not only a fascinating challenge but also central to numerous advanced applications in quantum information science. Here we report the nonlinear interaction between two single photons. Each photon is generated in independent parametric down-conversion sources. They are subsequently combined in a nonlinear waveguide where they are converted into a single photon of higher energy by the process of sum-frequency generation. Our approach results in the direct generation of photon triplets. More generally, it highlights the potential for quantum nonlinear optics with integrated devices and, as the photons are at telecom wavelengths, it opens the way towards novel applications in quantum communication such as device-independent quantum key distribution. PMID:25379916

  16. Ramsey interference with single photons

    Clemmen, Stéphane; Ramelow, Sven; Gaeta, Alexander L

    2016-01-01

    Interferometry using discrete energy levels in nuclear, atomic or molecular systems is the foundation for a wide range of physical phenomena and enables powerful techniques such as nuclear magnetic resonance, electron spin resonance, Ramsey-based spectroscopy and laser/maser technology. It also plays a unique role in quantum information processing as qubits are realized as energy superposition states of single quantum systems. Here, we demonstrate quantum interference of different energy states of single quanta of light in full analogy to energy levels of atoms or nuclear spins and implement a Ramsey interferometer with single photons. We experimentally generate energy superposition states of a single photon and manipulate them with unitary transformations to realize arbitrary projective measurements, which allows for the realization a high-visibility single-photon Ramsey interferometer. Our approach opens the path for frequency-encoded photonic qubits in quantum information processing and quantum communicati...

  17. Clinical studies on the thallium-201 myocardial scintiphotography in the patients with ischemic heart diseases

    Thallium-201 (201Tl) myocardial scintiphotography was performed in 34 patients with myocardial infarction and 13 with angina pectoris. Changing pattern of 201Tl activity in various organs observed. Myocardial blood flow was calculated from the relation of these activities. The body surface radioactivity of 201Tl decreased rapidly in initial phase, it gradually slowed down then reached to plateau on the heart and the lungs, while it increased gradually on the liver and kidneys. In patients with congestive heart failure, blood clearance of 201Tl was delayed and radioactivity on the lung area was increased compared with normal case. MBF/CO (%) ratio was calculated by the following way. Soon after the injection of 201Tl, serial images including whole chest were taken one frame in each one second during 30 seconds. Total injected dose was calculated from the maximum radioactivity in the frame. Myocardial uptake was calculated by the anterior view subtracting the mediastinal activity as the background at 5 minutes after the injection. MBF/CO (%) ratio was calculated as the myocardial uptake divided by the activity of total injected dose. Its mean value were 3.49 +- 0.45% in normals, 2.84 +- 0.47% in myocardial infarction and 3.00 +- 0.37% in angina pectoris, respectively, which showed significant low values in the latter two groups. MBF (ml/min/m2) = MBF/CO (%) x Cardiac index (CI). The mean value of MBF was 100.4 +- 12.7 ml/min/m2 in normals, 80.5 +- 21.1 in myocardial infarction and 77.3 +- 15.4 in angina pectoris, respectively, showing also significant low values in the latter two groups. Especially, MBF was most significant low in the groups of myocardial infarction with high serum CPK values. (author)

  18. Reverse redistribution of thallium-201 represents a low-risk finding in thrombolysed patients following myocardial infarction

    The aim of the study was to evaluate the prevalence and clinical significance of reverse redistribution on thallium-201 imaging in post-myocardial infarction patients who have undergone thrombolytic therapy. Sixty-two patients aged 35-79 (mean 60) years with proven myocardial infarction who had undergone thrombolysis were studied 6 weeks post infarction. Standard stress and 4-h redistribution imaging was performed with 201Tl following treadmill exercise. Separate day rest injection of 201Tl was given after sublingual nitroglycerine; imaging was performed at 1 h. Planar images were acquired in three standard views and semiquantitative segmental analysis of the images was performed from the unprocessed images. All patients had radionuclide ventriculography for the assessment of left ventricular ejection fraction and wall motion abnormality. Thirty-three patients also had coronary angiography. 201Tl scintigraphy revealed fixed defects in 19 patients, reversible defects in 22, and reverse redistribution in 21. Those with reverse redistribution had a significantly higher exercise capacity (P 201Tl uptake in the region showing reverse redistribution, with rest injection of 201Tl following sublingual nitroglycerine, suggesting viable myocardium in that region. (orig./VHE)

  19. Adsorption kinetics of {sup 201}Tl and migration of {sup 99m}Tc in natural soils; Cinetica de adsorcion de {sup 201}Tl y migracion de {sup 99m}Tc en suelos naturales

    Rodriguez N, C. E. [Instituto Tecnologico de Toluca, Av. Tecnologico s/n, Fraccionamiento La Virgen, 52149 Metepec, Estado de Mexico (Mexico); Monroy G, F.; Fernandez R, E.; Anguiano A, J., E-mail: estefany_rodriguezn@hotmail.com [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2012-10-15

    The safety is very important in facilities where radioactive wastes are stored. One of the necessary characteristics of the site where these wastes will be disposed is the soil permeability, since a waterproof terrain avoids the diffusion and radionuclide transport in the leakages case. The objective of this work is to study the adsorption kinetics of {sup 201}Tl and the migration of {sup 99m}Tc in natural soil samples. The adsorption kinetics was determined starting from the obtaining of the retention coefficient of the thallium (static method) at different contact times. The technetium diffusion was studied by means of the dynamic method with different soil particles sizes. The results showed that the thallium is totally adsorbed starting from 20 h of contact among this and the mean. On the other hand, the technetium is very mobile in the soil, since it was possible to extract the majority of the tracer with little solvent. Also, it was found that for each soil gram the double water will be needed to leach the technetium almost in its entirety. Moreover, influence exists of the particle size in the migration velocity from the radiotracer to the most mobile being in major sizes than 2 mm that in minor size. (Author)

  20. Precordial ST-segment depression during acute inferior myocardial infarction: clinical, scintigraphic and angiographic correlations

    The cause and associated pathophysiology of precordial ST-segment depression during acute inferior myocardial infarction (IMI) are controversial. To investigate this problem, electrocardiographic findings in 48 consecutive patients with acute IMI were prospectively compared with results of coronary angiography, submaximal exercise thallium-201 (201Tl) scintigraphy and multigated blood pool imaging, all obtained 2 weeks after IMI, and with clinical follow-up at 3 months. Patients were classified according to the admission ECG obtained 3.3 +/- 3.1 hours after the onset of chest pain. Twenty-one patients (group A) had no or 201Tl perfusion abnormalities (p201Tl defects or wall motion abnormalities in anterior or septal segments

  1. Development of a computer-aided diagnosis system using fuzzy inference in 201TlCl exercise myocardial scintigraphy

    We have been working on the development of a computer-aided diagnosis system for images in nuclear medicine by using artificial neural networks. A physician's diagnosis of coronary artery disease in nuclear cardiology is performed not only on the basis of imaging data but also includes other factors such as measurement data from exercise scintigraphy. Therefore, we propose an expert system that uses fuzzy inference to estimate the number of abnormal vessels in cases of single- or multi-vessel disease (including normal vessels) of the coronary arteries. The main characteristic of this system is that it integrates information from various sources, including the physician's impressions. In this study, we investigated the system's clinical effectiveness. Results indicated a rate of agreement between the system's confidence level of inference and the physician's diagnosis of 62.2% and a rate of sensitivity of 83% for coronary artery disease. The computer made it possible to utilize vague factors such as a physician's assessment based on experience and intuition. These results demonstrate the usefulness of our proposed technique. (author)

  2. Teleportation using squeezed single photons

    Branczyk, Agata M.; Ralph, T. C.

    2008-01-01

    We present an analysis of squeezed single photon states as a resource for teleportation of coherent state qubits and propose proof-of-principle experiments for the demonstration of coherent state teleportation and entanglement swapping. We include an analysis of the squeezed vacuum as a simpler approximation to small-amplitude cat states. We also investigate the effects of imperfect sources and inefficient detection on the proposed experiments.

  3. Engineered Quantum Dot Single Photon Sources

    Buckley, Sonia; Vuckovic, Jelena

    2012-01-01

    Fast, high efficiency, and low error single photon sources are required for implementation of a number of quantum information processing applications. The fastest triggered single photon sources to date have been demonstrated using epitaxially grown semiconductor quantum dots (QDs), which can be conveniently integrated with optical microcavities. Recent advances in QD technology, including demonstrations of high temperature and telecommunications wavelength single photon emission, have made QD single photon sources more practical. Here we discuss the applications of single photon sources and their various requirements, before reviewing the progress made on a quantum dot platform in meeting these requirements.

  4. Reproducibility of gated myocardial perfusion SPECT for the assessment of myocardial function: comparison with thallium-201 and technetium-99m-MIBI

    We compared the reproducibility of 291Tl and 99mTc-sestamibi (MIBI) gated SPECT (g-SPECT) for the assessement of myocardial function. G-SPECT acquisition for the assessment of myocardial function was repeated in the same position in 34 patients who received 201Tl and in 31 who received 99mTc-MIBI . The quantification of enddiastolic volume (EDV), endsystolic volume (ESV) and ejection fraction (EF) on 201Tl and 99mTc-MIBI g-SPECT were processed independently using Cedars quantitative g-SPECT software. The reporducibility of the assessment of myocardial function on 201Tl g-SPECT was compared to that of 99mTc-MIBI g-SPECT. Correlation between the two measurements for volumes and EF was excellent by the repeated g-SPECT studies of 291Tl(r=0.928 to 0.986; p99mTc-MIBI (r=0.979 to 0.997; p99mTc-MIBI g-SPECT(EDV: 14.1 ml, ESV; 9.4 ml and EF: 5.5%) than by repeated 201Tl g-SPECT (EDV: 24.1 ml, ESV: 18.6 ml and EF: 10.3%). The root mean square (RMS) values of the coefficient of variation (CV) for volumes and EFs were smaller by repeated 99mTc-MIBI g-SPECT (EDV: 2.1 ml. ESV 2.7 ml and EF:2.3%) than by repeated 2'01TI g-SPECT (EDV: 3.2 ml, ESV: 3.5 ml and EF: 5.2%). 99mTc-MIBI provides more reproducible volumes and EF and 201Tl on repeated acquisition s-SPECT. 99mTc-MIBI g-SPECT is the preferable method for the clinical monitoring of myocardial function

  5. Quantification of leg muscle perfusion using thallium-201 single photon emission computed tomography

    The purpose of this study is to quantify leg muscle perfusion with 201Tl single photon emission computed tomography (SPECT). Six normal controls and 21 patients with peripheral arterial disease underwent this examination. Thallium-201 leg SPECT of both stress and redistribution was performed using a dual-headed digital gamma camera. Each slice of transverse images was normalized with pixels and whole-body counts. In normal controls, the activity of posterior tibial muscle components was significantly higher than that of anterior tibial muscle components (p less than 0.001). In 14 components, where patients had insignificant lesions, profile curves were normal in 10 (71%). In 62 components, where patients had arteriographically significant lesions, stress profile curves were abnormal in 57 (92%) compared with normal controls. Approximately, in half (28/62) components which had significant lesions, profile curves showed redistribution after 3 hr compared with normal redistribution curves. In three patients who underwent successful bypass graftings, the activity of each muscle component returned to a normal range

  6. Spectral compression of single photons

    Lavoie, Jonathan; Wright, Logan G; Fedrizzi, Alessandro; Resch, Kevin J

    2013-01-01

    Photons are critical to quantum technologies since they can be used for virtually all quantum information tasks: in quantum metrology, as the information carrier in photonic quantum computation, as a mediator in hybrid systems, and to establish long distance networks. The physical characteristics of photons in these applications differ drastically; spectral bandwidths span 12 orders of magnitude from 50 THz for quantum-optical coherence tomography to 50 Hz for certain quantum memories. Combining these technologies requires coherent interfaces that reversibly map centre frequencies and bandwidths of photons to avoid excessive loss. Here we demonstrate bandwidth compression of single photons by a factor 40 and tunability over a range 70 times that bandwidth via sum-frequency generation with chirped laser pulses. This constitutes a time-to-frequency interface for light capable of converting time-bin to colour entanglement and enables ultrafast timing measurements. It is a step toward arbitrary waveform generatio...

  7. Caffeine reduces dipyridamole-induced myocardial ischemia

    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-201Tl 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

  8. Comparison of myocardial thallium and β-methyl iodophenyl pentadecanoic acid (BMIPP) distribution in cardiomyopathy 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 μCi) 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 cardiomyopathy hamsters, decreased uptake of BMIPP compared to that of thallium was demonstrated. These findings suggest dilated cardiomyopathy is associated with severe focal alternation 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. (author)

  9. Single photon response of photomultiplier tubes

    Beta or gamma rays, when directly incident on the window of an optically shielded photomultiplier tube, yield a typical single photon spectrum. The single photons are possibly generated in the glass window of the photomultiplier tube through excitation of atoms in glass by electrons. The coincidence resolving time has also been measured with a 60Co gamma source and a pair of optically shielded photomultiplier tubes detecting single photons. (orig.)

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

    Takeishi, Y; Chiba, J; Abe, S; Ikeda, K; Tonooka, I; Komatani, A; Takahashi, K; Nakagawa, Y; Shiraishi, T; Tomoike, H

    1992-09-01

    201Tl 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 201Tl was administered in a separate vein at the end of third minute 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 apical levels and a vertical long axis image at the mid left ventricle were used. The regions with decreased 201Tl 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 < 0.001). Chest pain (24%) and headache (13%) were the frequent side effects. The second-degree atrioventricular block was developed in 11 of 55 (20%) patients. All symptoms and hemodynamic changes were well tolerated and disappeared within 1 or 2 minutes after discontinuing adenosine infusion. The sensitivity and specificity for the detection of patients with coronary artery disease were 100% (31/31) and 88% (7/8), respectively. 201Tl myocardial imaging during adenosine infusion was considered to be safe and useful for evaluating the patients with ischemic heart disease. PMID:1453559