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Sample records for 201tl myocardial single-photon

  1. Evaluation of salvaged myocardium after acute myocardial infarction using single photon emission computed tomography after 201Tl-glucose-insulin infusion

    International Nuclear Information System (INIS)

    GIK-201Tl imaging reportedly improves the detection of viable myocardium, so the present study evaluated whether it can detect myocardial viability after acute myocardial infarction (AMI). Resting 201Tl and 99mTc-pyrophosphate (PYP) dual single photon emission computed tomography (SPECT) and 201Tl SPECT after 201Tl with GIK (10% glucose, insulin 5 U, and KCl 10 mmol) infusion (GIK-201Tl) were performed in 25 AMI patients within 10 days of admission. GIK-201Tl SPECT images were obtained immediately and 4 h after infusion. Left ventriculography (LVG) was performed within 3 weeks and at 6 months when follow-up 201Tl SPECT was also performed. From 20 SPECT segments, both the summed defect score (RDS) and the number of defect segments (ES) were calculated. The infarcted area was defined as 99mTc-PYP uptake segments. Wall motion was estimated in 7 LVG segments. The ES of R-201Tl (5.5±2.8), immediate GIK-201Tl (4.0±2.3), and 4-h GIK-201Tl (5.6±2.7) were lower than that of 99mTc-PYP (7.5±4.1) (p201Tl (3.5±2.8) (p201Tl (11.3±7.9) and 4-h GIK-201Tl (11.2±6.3) were greater than at the 6-month 201Tl (7.1±6.5), immediate GIK-201Tl (7.4±6.5) was equivalent to follow-up 201Tl. The sensitivity of immediate GIK-201Tl was highest among the imaging methods. To detect myocardial viability after AMI, early imaging with GIK-201Tl is more useful than resting 201Tl imaging. (author)

  2. Assessment of left ventricular function using 201Tl electrocardiogram-gated myocardial single photon emission computed tomography

    International Nuclear Information System (INIS)

    Advances in computed tomography (CT) technology make it possible to obtain left ventricular wall motion using 3D reconstruction. In this study, we compared the images obtained from CT and 201Tl electrocardiogram (ECG) gated single photon emission computed tomography (SPECT). In 20 patients with ischemic heart disease, we performed 201Tl ECG gated SPECT (GE Healthcare Millennium VG) and ECG gated CT (Philips Medical Systems Brilliance iCT) to evaluate of left ventricular wall motion during the resting phase. In SPECT, left ventricular images were reconstructed using quantitative gated SPECT (QGS) software. In CT, the images were reconstructed using Virtual Place (AZE Software). The left ventricle was classified into five regions (anterior, lateral, inferior, septal, and apical). The amplitude of the wall motion was classified into five grades according to AHA classification. The values of the wall motion were separately checked by two radiographers. Assessment of left ventricular function myocardial wall movement using the three-dimensional movie display with ECG gated myocardial SPECT data was in agreement with the evaluation by cardiac CT inspection, and corresponded with wall motion in 88 of all 100 segments. SPECT analysis has the same quantity as that of obtained from CT for evaluation of left ventricular wall motion. (author)

  3. 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

    International Nuclear Information System (INIS)

    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)

  4. Single photon emission computed tomography using rotating dual gamma-camera for 201Tl myocardial imaging in patients with ischemic heart disease

    International Nuclear Information System (INIS)

    Exercise 201Tl myocardial scintigraphy was performed for comparison between single photon emission computed tomography (SEPCT) and the conventional planar method. The detection rate for ischemic heart diseases was 98% by SPECT and 86% by the planar method. The detection rate of transient ischemia in the myocardial infarction group was 70% by SPECT, 34% by the planar method and 40% by ECG (ST depression). In segmental analysis the sensitivity for the left anterior descending artery, left circumflex artery and right coronaty artery was 86%, 68% and 83%, respectively, by SPECT and 61%, 60% and 57% by the planar method. SPECT thus elevated the sensitivity in ischemic heart diseases and allowed estimation of coronary artery diseases. (Chiba, N.)

  5. Usefulness and limitation of stress 201Tl myocardial single photon emission computed tomography (SPECT) for diagnosis of ischemic heart disease

    International Nuclear Information System (INIS)

    Stress 201-T1-myocardial single photon emission computed tomography (SPECT) proved to have significantly higher sensitivity than planar scintigraphy for the detection of ischemic heart disease (IHD), each affected artery, multi-vessel disease and three-vessel disease. It also permitted the detection of ventricular aneurysm. Diagnostic accuracy was influenced by the presence and severity of infarction, the number of affected vessels, and infarct site. Transient ischemia in the infarct site and ventricular aneurysm seemed to make it difficult to detect multi-vessel disease in cases of infarction. These resu lts indicated that SPECT is a noninvasive useful technique for detecting IHD, each affected artery, multi-vessel disease (especially, postero-inferior myocardial infarction), three-vessel disease, and ventricular aneurysm. However, SPECT seemed to have the limitation for detecting multi-vessel disease accompanied by anterior myocardial infarction and angina pectoris. (Namekawa, K.)

  6. 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

    International Nuclear Information System (INIS)

    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)

  7. Quantification of infarct size by 201Tl single-photon emission computed tomography during acute myocardial infarction in humans. Comparison with enzymatic estimates

    International Nuclear Information System (INIS)

    We prospectively investigated whether 201Tl single-photon emission computed tomography (SPECT) could accurately diagnose the presence and quantify the extent of acute myocardial infarction when compared with infarct size assessed by plasma MB-creatine kinase activity. Thirty patients with enzymatic evidence of infarction were imaged within 12-36 hours of chest pain (mean, 23.4 hours). No patient had a previous infarction, and none underwent intervention seeking to restore coronary patency. Infarct size was quantified with computer-generated polar maps of the myocardial radioactivity and expressed as a percentage of the total left ventricular volume. To assess left and right ventricular performance, blood-pool gated radionuclide angiography was performed immediately after SPECT. All 30 patients had perfusion defects consistent with myocardial infarction. Scintigraphic and enzymatic estimates of infarct size correlated well for the group as a whole (r = 0.78, p less than 0.001, SEE = 9.1) but especially for those patients with anterior infarction (r = 0.91, p less than 0.001, SEE = 7.9). The poor correlation observed in patients with inferior infarction (r = 0.50, p less than 0.05, SEE = 10.0) was believed to be related to the frequent occurrence of right ventricular involvement because SPECT assessed only left ventricular damage, whereas the enzymatic method estimated the myocardial injury in both ventricles. A quantitative index of right ventricular infarct size, derived from the relation between the scintigraphic and enzymatic estimates, had a strong inverse correlation with right ventricular ejection fraction (r = -0.89, p less than 0.001, SEE = 3.6)

  8. Evaluation of Agreement between 64-slice Computed Tomography Angiography and 201-Tl Single Photon Emission Computed Tomography-myocardial Perfusion Imaging in the Diagnosis of Significant Coronary Artery Disease

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    Ma, Jee Hyun; Kang, Doo Kyoung [Dept. of Radiology, Ajou University School of Medicine, Suwon (Korea, Republic of); Lee, Su Jin; An, Young Sil [Dept. of Nuclear Medicine, Ajou University School of Medicine, Suwon (Korea, Republic of); Lim, Hong Seok [Dept. of Cardiology, Ajou University School of Medicine, Suwon (Korea, Republic of)

    2011-06-15

    To compare coronary computed tomography angiography (CTA) with single photon emission computed tomography-myocardial perfusion imaging (SPECT-MPI) for the detection of physiologically significant coronary artery disease (CAD). We evaluated 202 patients undergoing 64-slice coronary CTA and 201-Tl SPECT-MPI within a 3-month time interval. In addition, 68 patients underwent invasive coronary angiography (ICA). Coronary artery stenoses with luminal narrowing {>=} 50% were defined as 'significant' on CTA and ICA. All myocardial segments were classified as reversible or fixed perfusion defects and normal segments on 201-Tl SPECT-MPI, and were allocated to the corresponding coronary vessels. Agreement and diagnostic performance between each imaging modality for physiologically significant CAD was calculated using the kappa ({kappa}) statistic and receiver operating characteristic analysis, respectively. The sensitivity and specificity of CTA for the detection of physiologically significant CAD were 88% and 86% by patient-based analysis, and 84% and 91% by vessel-based analysis as compared to 201-Tl SPECT-MPI, respectively. The agreement between CTA and SPECTMPI was good ({kappa} = 0.647) and moderate ({kappa} = 0.558) by patientand vessel-based analyses, respectively. The accuracy of CTA for predicting perfusion defects on SPECT-MPI was comparable (area under the curve; 0.814 vs. 0.819, p=0.902 on patient-based analysis, and 0.808 vs. 0.749, p=0.197 on vessel-based analysis) to ICA. Coronary stenosis {>=} 50% on coronary CTA shows good agreement with perfusion defects in SPECT-MPI.

  9. Myocardial scintigraphy with 201Tl in angiosarcoma of the heart

    International Nuclear Information System (INIS)

    The appearance of angiosarcoma of the heart in the myocardial image with 201Tl is described on hand of an casuistic example. This diagnostic procedure may be important for follow-up of therapeutic effects. (orig.)

  10. Prediction of functional recovery and prognosis in patients with acute myocardial infarction by 123I-BMIPP and 201Tl myocardial single photon emission computed tomography. A multicenter trial

    International Nuclear Information System (INIS)

    Patients with uncomplicated first acute myocardial infarction (AMI) underwent resting 123I-BMIPP and 201Tl myocardial SPECT in the subacute phase after the onset of AMI. Of these, 167 patients who had been followed up for an average of 22 months were retrospectively reviewed to predict serious cardiac events and recurrent ischemia. In addition, the association between changes in radionuclide parameters and recurrent ischemia was investigated in Subgroup A (58 patients) who had repeated SPECT in the chronic phase. Furthermore, prediction of the ejection fraction (EF) was investigated in Subgroup B (94 patients) and Subgroup C (76 patients) in whom left ventriculography was performed at the time of discharge and 90 days or more after the onset, respectively. The prognosis was generally favorable, with 4 cases of cardiac death (2%), 3 of heart failure (2%), 4 of nonfatal reMI (2%), and 25 of recurrent ischemia (15%). The results of Cox multivariate regression analysis revealed a high probability of serious cardiac events in patients who were elderly, who had 90% or more residual stenosis of the infarct-related artery, and who had a high BMIPP defect score. There was a high probability of recurrent ischemia in elderly patients who had multi-vessel disease, but no association was found with radionuclide parameters in the subacute phase. In Subgroup A, however, the probability of recurrent ischemia tended to be high in patients with a large mismatch score between 123I-BMIPP and 201Tl in the subacute to chronic phase. An important observation was that the extent of BMIPP defect was more strongly correlated with EF at the time of discharge and 90 days or more after the onset than the extent of Tl defect. In addition, multiple regression analysis showed that parameters related to the BMIPP defect were also better predictive factors of EF both at the time of discharge and 90 days or more after the onset. (K.H.)

  11. The value of adenosine triphosphate stress 201Tl myocardial SPECT for detecting coronary artery disease

    International Nuclear Information System (INIS)

    Objective: To investigate the diagnostic value of adenosine triphosphate (ATP) 201Tl myocardial SPECT for coronary artery disease. Methods: 201Tl was injected after administration of adenosine triphosphate (0.14 mg·kg-1·min-1, 3 min). Myocardial SPECT imaging was performed at ten minutes and 3-4 hours after injection of 201Tl. Results: The sensitivity and specificity of ATP 201Tl imaging for detecting coronary artery disease was 88% and 90%, respectively. The side effects were mild and transient. Conclusion: ATP 201Tl imaging for detecting coronary artery disease is feasible

  12. Segmental analysis of SPECT 99mTc-methoxy isobutyl isonitrile and 201Tl myocardial imaging in ischaemic heart disease

    International Nuclear Information System (INIS)

    To study the potential usefulness of 99mTc-methoxy isobutyl isonitrile (99mTc-MIBI) as a substitute for 201Tl in assessing patients with ischaemic heart disease, 24 patients underwent 1 day rest and exercise 99mTc-MIBI single photon emission computerised tomography (SPECT) 1 week after SPECT exercise 201Tl. All patients were catheterized within 1 month after myocardial imaging. In 17 patients, resting first pass radionuclide angiograpy (FPRNA) was performed with 99mTc-MIBI. The heart to lung ratio for 99mTc-MIBI and 201Tl was calculated both at rest and exercise. The segmental analysis for myocardial perfusion reveals that 87/96 segments (91%) were correctly classified by SPECT 201Tl and 84/96 segments (88%) were correctly classified by 99mTc-MIBI. A significant correlation was present between LVEF measured by 99mTc-MIBI FPRNA and contrast ventriculography (r=0.85, P99mTc-MIBI is significantly higher than 201Tl (P99m-Tc-MIBI is a promising agent for simultaneous evaluation of myocardial perfusion and cardiac function. (orig.)

  13. Radiation exposure around patients after 201Tl-myocardial scintigraphy

    International Nuclear Information System (INIS)

    Aim: It was the aim of the study to assess the additional radiation exposure to patients, attendents and nurses by patients who are undergoing nuclear medicine investigations (myocardial scintigraphy) with 201Tl-chloride (201Tl-Cl). Methode: In 16 cases the dose rates at 0.5, 1 and 2 m distance from patients were measured at 0.5, 1.5, 3-4 and 24, in some cases until 370 h after administration of 100±10 MBq 201Tl-Cl. From the time courses of the dose rates around the patients the possible radiation exposure of other persons were estimated. Results: The initial values of the dose rate were 3.82 ?Sv/h at 0.5 m, 1.18 ?Sv/h at 1 m and 0.30 ?Sv/h at 2 m distance from the patients respectively. The dose rates were decreasing following a monoexponential course with an effective half-life of 60 h. The maximum doses to other persons at 1 m distance from the patients were determined by considering three scenarios. The values were 13 ?Sv in the waiting room, 26 ?Sv for nurses working in the ward and 105 ?Sv for persons living in the same household. Conclusion: Even at very restrictive assumptions the doses were far below the maximum permissible dose to non-radiation workers set by radiation protection regulations (1.5 mSv per year). (orig.)

  14. 123I-labelled BMIPP fatty acid myocardial scintigraphy in patients with hypertrophic cardiomyopathy: SPECT comparison with stress 201Tl

    International Nuclear Information System (INIS)

    123I-labelled 15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) myocardial single photon emission computed tomography (SPECT) was performed in 17 patients with hypertrophic cardiomyopathy, and was compared with 201Tl exercise stress myocardial perfusion (SPECT) images. Fourteen patients showed asymmetrical hypertrophy, and three demonstrated apical hypertrophy. SPECT was performed 20 min and 3 h after injection of 111 MBq 123I-BMIPP at rest. Exercise stress 201Tl SPECT was performed at 10 min and 3 h after injection and was compared with BMIPP imaging. In 13 patients BMIPP accumulation in the hypertrophied area in the 20 min image was lower that that of 3 h 201Tl uptake. Interestingly, six patients demonstrated 201Tl redistribution in the region where the uncoupling of BMIPP uptake at 20 min and 201Tl accumulation at 3 h after exercise was observed. These findings suggest that impaired fatty acid metabolism or utilization in hypertrophic myocardium and ischaemia or impaired coronary flow reserve may be one of the causes of the abnormality of fatty acid accumulation. (Author)

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

    International Nuclear Information System (INIS)

    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

  16. 201Tl myocardial tomography with polar bullseye plot display

    International Nuclear Information System (INIS)

    In this study, 13 normal subjects and 43 CHD patients underwent 201Tl myocardial SPECT were presented and analysed with Polar Bullseye Plot (PBP). The sensitivity of tomography and PBP for detecting CHD was 93.0% and 97.6% respectively (P > 0.05). The specificity of both techniques was the same (92.3%). The sensitivity of tomography and PBP for detecting CHD patients with 1, 2 and 3 vessel lesion was 86.7% and 86.7%, 92.3% and 100%, 100% and 100%, respectively. The general sensitivity for detecting stenosed vessels was 84.7%. The sensitivity for examing severe stenosed vessel was higher than that for mild one (P LAD < LCX. As compared with general inspection of the image, obviously the advantage of PBP was objective, semi-quantitative and easy for glance over

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

    International Nuclear Information System (INIS)

    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)

  18. 201Tl in myocardial diagnosis: studies on the influence of dipyridamole, dobutamine ergometer exercise and background subtraction on the 201Tl myocadial scintiscam

    International Nuclear Information System (INIS)

    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.)

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

    International Nuclear Information System (INIS)

    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

  20. Assessment of myocardial viability with 201Tl myocardial SPECT 24 hours after injection

    International Nuclear Information System (INIS)

    Recently many investigators reported that conventional stress-redistribution myocardial scintigraphy with 201Tl underestimated the presence of ischemia but viable myocardium. We studied single photon emission computed tomography (SPECT) to assess myocardial viability and investigated the factors affecting the quality of 24 hour SPECT images. Study patients were comprised of 70 patients with old myocardial infarction (OMI), 72 patients with angina pectoris without OMI (AP), and 43 patients with angiographically proven normal coronary arteries. To obtain SPECT images, 10 minute and 4 hour imagings were sampled 30 seconds per projection. Twenty-four hour imaging was sampled 60 seconds per projection. Twenty-four hour images were visually interpreted as good, moderate, and poor quality. Then study patients were divided into 2 groups, group A with good 24 hour images and group B with moderate or poor 24 hour images. One hundred and fifty-eight patients (85.4%) of study patients had 24 hour SPECT images on a good quality. Only 4 patients (2.2%) had poor quality SPECT. All of these 4 patients had broad myocardial infarction. In patients with OMI 61 patients (87.1%) in AP 63 patients (87.5%) and in normal 35 patients (81.4%) had a good 24 hour SPECT. Total sampling counts and myocardial ROI counts were significantly higher in group A than in group B. Body weight was significantly higher and there were more male patients in group B than in group A. Late redistribution was seen in 20 patients (28.5%) with OMI and in 11 patients (15.3%) with AP. In most patients with OMI and AP we can get 24 hour SPECT on a good quality. In patients with moderate or poor 24 hour SPECT sampling counts were significantly reduced. So, it may be possible to get good quality 24 hour image with longer sampling time. (author)

  1. Clinical evaluation of 201Tl single photon emission computed tomography in patients with large opacities due to silicosis and in those with bronchogenic carcinoma

    International Nuclear Information System (INIS)

    201Tl single photon emission computed tomography (201Tl SPECT) was used to evaluate 18 patients with large opacities due to silicosis and 22 others with bronchogenic carcinoma. An early scan and a delayed scan were obtained and the retention index was calculated from the early ratio and the delayed ratio. In patients with silicosis, the retention index and the two ratios were significantly lower than in the patients with bronchogenic carcinoma (p201Tl SPECT is useful for evaluating the activity of large opacities in patients with silicosis and for differentiating large opacities caused by silicosis from those caused by bronchogenic carcinoma. (author)

  2. 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

    International Nuclear Information System (INIS)

    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)

  3. Detecting viable hibernating myocardium in chronic coronary artery disease. A comparison of resting {sup 201}Tl single photon emission computed tomography (SPECT), {sup 99m}Tc-methoxy-isobutyl isonitrile SPECT after nitrate administration, and {sup 201}Tl SPECT after {sup 201}Tl-glucose-insulin infusion

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    Toyama, Takuji; Hoshizaki, Hiroshi; Isobe, Naoki; Adachi, Hitoshi; Naito, Shigeto; Oshima, Shigeru; Taniguchi, Koichi [Gunma Prefectural Cardiovascular Center, Maebashi (Japan)

    2000-12-01

    To identify and quantify the amount of viable hibernating myocardium in patients with chronic coronary artery disease, resting {sup 201}Tl single photon emission computed tomography (SPECT) was compared with {sup 99m}Tc-methoxy-isobutyl isonitrile (MIBI) SPECT after nitrate infusion (nitrate-{sup 99m}Tc-MIBI) and {sup 201}Tl SPECT after {sup 201}Tl with glucose-insulin-potassium infusion ({sup 201}Tl-GIK) in 25 patients. Twenty-one patients also underwent completely left ventriculography beforehand and 5{+-}4 months afterwards. SPECT images were divided into 9 segments and scored visually from 0 (normal uptake) to 3 (absent). The defect score was calculated as the summation of the total scores (TDS) in each patient. The TDS of nitrate-{sup 99m}Tc-MIBI images (6.3{+-}4.3) and {sup 201}Tl-GIK images (5.8{+-}4.2) were significantly lower than the 7.4{+-}4.3 of resting {sup 201}Tl images (p<0.01). Based on the improvement of wall motion after coronary revascularization, the sensitivity of {sup 201}Tl-GIK imaging (85%) was significantly higher (p<0.05), and that of nitrate-{sup 99m}Tc-MIBI imaging (79%) also tended to be higher (p=0.08), than that of {sup 201}Tl imaging (62%) in detecting viable myocardium. The specificity of the 3 methods was almost the same. The nitrate-{sup 99m}Tc-MIBI and {sup 201}Tl-GIK methods were more useful than the resting {sup 201}Tl method for evaluating viable hibernating myocardium. Furthermore, the {sup 201}Tl-GIK method may provide a more accurate estimate of the amount of viable myocardium than the nitrate-{sup 99m}Tc-MIBI method. (author)

  4. Degradation of myocardial perfusion SPECT images caused by contaminants in thallous (201Tl) chloride

    International Nuclear Information System (INIS)

    Thallous (201Tl) chloride is a single-photon emission computed tomography (SPECT) tracer mainly used for assessing perfusion and viability of myocardial tissue. 201Tl emits X-rays around 72 keV and gammas at 167 keV, and has a half-life of 73 h. Regulations allow an intrinsic contamination up to 3-5%, which is mainly caused by 200Tl (368 keV; 26 h) and by 202Tl (439 keV; 12.2 days). Contra-intuitive to the low-level percentages in which these contaminants are present, their impact may be significant because of much higher gamma camera sensitivity for these high-energy photon emissions. Therefore, we investigate the effects of the contaminants in terms of detected fractions of photons in projections and contrast degradation in reconstructed images. Acquisitions of a digital thorax phantom filled with thallous (201Tl) chloride were simulated with a validated Monte Carlo tool, thereby, modelling 1% of contamination by 200Tl and 202Tl each. In addition, measurements of a thorax phantom on a dual-headed gamma camera were performed. The product used was contaminated by 0.17% of 200Tl and 0.24% of 202Tl at activity reference time (ART). This ART is specified by the manufacturer, thereby, accounting for the difference in half-lives of 201Tl and its contaminants. These measurements were repeated at different dates associated with various contamination levels. Simulations showed that, with 1% of 200Tl and 202Tl, the total contamination in the 72 keV window can rise up to one out of three detected photons. For the 167keV window, the contamination is even more pronounced: more than four out of five detections in this photopeak window originate from contaminants. Measurements indicate that cold lesion contrast in myocardial perfusion SPECT imaging is at maximum close to ART. In addition to a higher noise level, relative contrast decreases 15% 2 days early to ART, which is explained by an increase in 200Tl contamination. After ART, contrast decreased by 16% when the 202Tl contamination increased to the maximal allowed limit. Contra-intuitive to the low-level percentages in which they are typically present, penetration and downscatter of high-energy photons from 200Tl and 202Tl significantly contribute to thallous (201Tl) chloride images, thereby, reducing contrast and adding noise. These findings may prompt for improved production methods, for updated policies with regard to timing of usage, and they also render the usefulness of adding the high photopeak window (167 keV) questionable. A window-based correction method for this contamination is advisable. (orig.)

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

    International Nuclear Information System (INIS)

    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)

  6. Myocardial scintigraphy with 201Tl in coronary disease

    International Nuclear Information System (INIS)

    106 normal subjects, infarct patients or patients with signs of ischemic ECG were examined by 201Tl-scintigraphy. A dosis of 1.5 mCi immediately resulted in satisfactory scintiscanner images, as well as with the gamma camera. 81% of the patients with anterior infarction, 63% of patients with inferior infarction and 22% of patients with sub-epicardial ischemia showed characteristic scintigraphic anomalies. 201Tl was therefore demonstrated to be a valuable tracer for anterior infarction diagnosis. It was found to be less exact in inferior infarction, although still superior to the 131Cs hitherto used by the authors

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

    International Nuclear Information System (INIS)

    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)

  8. Evaluation of 201Tl myocardial tomography in detecting coronary heart disease

    International Nuclear Information System (INIS)

    The diagnostic value of 201Tl myocardial tomographic imaging in coronary heart diseases were studied in 31 cases of coronary heart disease and 15 normal subjects, compared with coronary angiography. The sensitivity and specificity of myocardial tomography were 97% and 80% respectively. The sensitivity in identifying one-vessel, two-vessels and three-vessels of coronary artery stenosis were 100%, 83% and 44% respectively. The detectability of LAD, RCA and LCX lesions were 95%, 93% and 59% respectively. It is concluded that 201Tl myocardial tomography is a valuable procedure for the early diagnosis and localization of coronary stenosis

  9. Two dimensional polar coordinate representation (bulls-eye view) method of the 201Tl myocardial SPECT

    International Nuclear Information System (INIS)

    Two dimensional polar coordinate representation (bulls-eye view) method was applied to the 201Tl myocardial imaging by single photon emission CT (SPECT) and this method was compared with a conventional SPECT image for the ability to detect the abnormalities. We examined 5 normals and 15 patients (10 angina pectolis and 5 myocardial infarction), whose diagnosis were confirmed by coronary angiography. Diagnostic efficacy of two methods was evaluated in two groupes of radiologists by means of ROC (receiver operating characteristic) curve. Radiologists in A group have three years experience or more in nuclear medicine and those in B group have less than one year experience. As a result, diagnostic accuracy of conventional method was 93 % in a group and 55 % in B group. The accuracy by the two polar coordinate representation was increased from 55 % to 86 % in B group, although no remarkable improvement was seen in the accuracy (90 %) of A group. The consuming time for diagnosis was shortend by using the two dimensional polar coordinate representation method, especially in B group. This result suggests that the two dimensional polar coordinate representation method is useful for reading the myocardial imaging in not-well trained radiologists as well as in the well trained. (author)

  10. Evaluation of infantile ventricular tachycardia by sup 201 Tl myocardial SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Akanabe, Hiroshi; Sakuma, Sadayuki (Nagoya Univ. (Japan). Faculty of Medicine); Ohshima, Motoo

    1992-04-01

    {sup 201}Tl myocardial SPECT findings in infantile ventricular tachycardia (VT) were examined. The subjects were 4 cases of infantile VT subjected exercise-loading {sup 201}Tl 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 {sup 201}Tl myocardial SPECT enables us to search for etiology of VT, prognosis and the like. (author).

  11. Usefulness of {sup 201}Tl/{sup 123}I-BMIPP myocardial SPECT to evaluate myocardial viability and area at risk in acute myocardial infarction. Comparison with {sup 201}Tl/{sup 99m}Tc-PYP dual SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Isobe, Naoki; Toyama, Takuji; Hoshizaki, Hiroshi; Oshima, Shigeru; Taniguchi, Koichi [Gunma Prefectural Cardiovascular Center, Maebashi (Japan)

    1997-04-01

    To evaluate the area at risk and the myocardial viability of acute myocardial infarction (AMI), we compared rest {sup 123}I-beta-methyl iodophenyl pentadecanoic acid ({sup 123}I-BMIPP) and {sup 201}Tl myocardial SPECT with {sup 201}Tl/{sup 99m}Tc-PYP dual SPECT (D-SPECT) in 65 patients (mean age 64{+-}11 years) with AMI. D-SPECT was performed in 3 to 5 days, {sup 123}I-BMIPP myocardial SPECT in 5 to 7 days, and left ventriculography on 1 month after onset of AMI. Furthermore, {sup 201}Tl/{sup 123}I-BMIPP myocardial SPECT and left ventriculography were performed on 4 months after onset of AMI. The area which showed the reduced {sup 123}I-BMIPP uptake was larger than that showed the accumulation of {sup 99m}Tc-PYP. The improvement of regional wall motion on 4 months after onset of AMI tended to be more closely correlated with the existence of discrepancy zone between {sup 201}Tl and {sup 123}I-BMIPP uptake than that of overlap zone between {sup 201}Tl and {sup 99m}Tc-PYP uptake in acute period. We conclude that {sup 201}Tl/{sup 123}I-BMIPP myocardial SPECT is more useful to evaluate the area at risk and myocardial viability of AMI than D-SPECT. (author)

  12. Scintigraphy of the heart with the aid of 201Tl in diagnosis of acute myocardial infarction

    International Nuclear Information System (INIS)

    In patients with acute myocardial infarction of different localization by the method of heart scitigraphy using 201Tl irradiation doses, extraction factors in myocardium, 201Tl distribution in the heart are considered. A good correlation between ECG data and scintigraphy as to myocardium localization is pointed out. Advantages (availability, acceptable radiation doses, high sensitivity for the first 12-24 hours after the appearence of first symptoms etc.) and disadvantages (impossibility of the differentiating of acute, developing or ''chronic'' infarction) of the method are shown

  13. Quantitative analysis of 123I-BMIPP imaging in relation to exercise-redistribution 201Tl in patients with old myocardial infarction

    International Nuclear Information System (INIS)

    Myocardial kinetics of 123I-labeled 15-(p-iodophenyl) 3R, S-methylpentadecanoic acid (BMIPP) was evaluated with BMIPP imaging in conjunction with stress-201Tl. We studied 20 patients with old myocardial infarction. BMIPP SPECT was obtained at 20 min and 3 h after injection. On a separate day, exercise stress-201Tl SPECT was performed at 10 min and 3 h after injection. Then, left ventricular myocardium was divided into 20 segments. For quantitative analysis, in each SPECT data, the maximum value (average counts per pixel) of all 20 myocardial segments was taken as 100%; the other values were calculated as a percentage of this maximum (Relative regional uptake, RRU). On the basis of stress-201Tl pattern, the myocardial segments were classified into 4 groups; normal 201Tl uptake, reversible 201Tl defect, fixed 201Tl defect and 201Tl defect with reverse redistribution. The 20 min BMIPP showed reduced activity compared with 3 h-201Tl (p201Tl redistribution (50/111 segments, 45%), implicating impaired fatty acid utilization at resting condition. The washout rate of the segments with reversible 201Tl defect (-1.6±13.9%) was significantly lower than that of the segments with normal 201Tl uptake (9.0±9.8%) and fixed 201Tl defect (3.8±12.9). Thus, BMIPP in combination with stress 201Tl imaging provides precise information on impaired myocardial fatty acid utilization in patients with old myocardial infarction. (author)

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

    International Nuclear Information System (INIS)

    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

  15. The role of 201Tl SPECT in detecting myocardial viability in patients undergoing trans-myocardial laser revascularization

    International Nuclear Information System (INIS)

    Objective: To evaluate the value of detecting viable myocardium by 201Tl SPECT myocardial imaging in trans-myocardial laser revascularization (TMLR). Methods: 19 patients with prior myocardial infarction and unstable angina confirmed by coronary angiography underwent TMLR. Before TMLR, dipyridamol stress test (ST)-'redistribution' (RD)-nitroglycerin (NTG) infusion re-injecting (NTG+RI)201Tl SPECT myocardial imaging were performed on all 19 patients. Of 56 segments of left ventricle with myocardial ischemia or infarction found by 201Tl SPECT imaging, 45 segments (physicians' decision) underwent TMLR using a high energy (800 W) CO2 laser. TMLR was performed on the free walls of the left ventricle of the beating heart. The average numbers of trans-myocardial channels on various segments were: 8.3 +- 2.9 on anterior wall, 6.5 +- 2.5 on lateral wall, 5.4 +- 2.0 on inferior wall, 5.3 +- 4.4 on apex. 3, 6 to 12 months after TMLR, ST-RD-NTG+RI 201Tl SPECT imaging was repeated in 19 patients, and then followed up for 3 months in 17 cases, 6 months in 11 cases, 1 year in 5 cases. Results: Of 45 segments which had TMLR, 18 segments (40%) showed improved perfusion of myocardium. Of 18 segments showed marked redistribution before TMLR, 14 segments (77.8%) were improved in myocardial perfusion after TMLR. All of 8 segments showed marked redistribution in RD imaging before TMLR showed improved myocardial perfusion after TMLR. Among 27 segments without redistribution in RD-NTG+RI 201Tl myocardial imaging, only 4 segments (14.8%) showed improved perfusion after TMLR. Conclusions: Stress test-redistribution-NTG infusion + reinjection 201Tl myocardial imaging is a valuable procedure to select patients for TMLR and to evaluate results of TMLR therapy

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

    International Nuclear Information System (INIS)

    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)

  17. Effect of wall thickness of left ventricle on 201Tl myocardial SPECT images. Myocardial phantom study

    International Nuclear Information System (INIS)

    201Tl 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)

  18. Quantitative assessment of myocardial blood flow by measurement of fractional myocardial uptake of 201Tl

    International Nuclear Information System (INIS)

    Fractional Myocardial uptake of 201Tl was measured for the quantitative assessment of myocardial blood flow in coronary artery disease (CAD). 10 normals and 28 CAD, 7 of which have less than 50% stenosis (CAD I) and 21 of which have more than 50% stenosis (CAD II) in the proximal portion of coronary arteries, were studied at rest and with submaximal exercise loading by bicycle ergometer. After intravenous injection of 201Tl, its rapid transport process was recorded during the initial 5 minutes by a scintillation camera and a minicomputer. Total injected dosage (T) was obtained from the counts of the entire chest region during the initial passage of the tracer through the heart and lung. Myocardial uptake (M) was counted with the same geometry from the subsequent accumulation within the myocardial region with subtraction of the background activities in the upper mediastinal region (B). The fractional myocardial uptake of 201Tl ((M-B)/T) is assumed to be proportional to the fractional myocardial blood flow to cardiac output (MBF/CO) according to the indicator fractionation principle. The average value of MBF/CO at rest in CAD (4.11 +- 1.12%) was significantly greater than in normals (3.36 +- 0.49%), which may be caused by an increased left ventricular mass in CAD. Change rate of MBF/CO on the exercise loading was significantly less in CAD I (1.36 +- 0.14) and in CAD II (1.11 +- 0.21) than in normals (1.75 +- 0.11). MBF/CO increased proportionally to the increment of the double product of heart rate and systolic blood pressure by exercise loading in normals, whereas it didn't in CAD. The sensitivity of this method was superior to the stress electrocardiogram and the stress myocardial perfusion imaging, not only in CAD II but also in CAD I. This result indicated that this type of global assessment of the myocardial reserve capacity is valuable in addition to the simple stress myocardial perfusion imaging. (author)

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

    International Nuclear Information System (INIS)

    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 (?LVEF) 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 ?LVEF (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)

  20. Clinical evaluation of efonidipine hydrochloride in angina pectoris. Evaluation in exercise 201Tl myocardial scintigraphy

    International Nuclear Information System (INIS)

    Clinical usefulness of once-daily administration of 20 to 60 mg of efonidipine hydrochloride and coronary hemodynamics during exercise 201Tl myocardial scintigraphy were investigated in patients with angina pectoris. Out of 11 patients enrolled in this study, 9 patients were included in the evaluation of patients' impression, in improvement rating in subjective symptoms, in the analysis of the exercise test, in the improvement rating of images on 201Tl myocardial scintigraphy, and in the global improvement rating, while 10 patients were included in the overall safety rating. Four patients in improvement rating in subjective symptoms, 2 in improving rating in the exercise test, and 5 in the global improvement rating were rated 'improved' or better. In the improvement rating on the exercise 201Tl myocardial scintigraphy image, reduction of the image was observed in 5 patients, 3 out of which were evaluated as 'improved' or better. A distinctive reduction of ischemic regions was observed in 2 patients out of the 3. A significant decrease in the number of angina pectoris events and a decreasing tendency in consumption of fast-acting nitrates were observed in spite of the low number of the patients studied. An adverse effect was observed in 1 patient and abnormal laboratory values were observed in 2 patients which were improved promptly after withdrawal of the drug. It was in 7 patients evaluated as 'no problem', while in 4 patients it was evaluated as 'useful' or more. (author)

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

    DEFF Research Database (Denmark)

    Charabi, Samih Ahmed; Lassen, N A; Thomsen, J; Tos, M; Rossen, Karina Jervelund; Jacobsen, G K

    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. The relative tracer concentration and uptake were correlated to tumor volume determined by gadolinium DTPA enhanced MR, to prediagnostic duration of symptoms, to tumor vascularity expressed by the avera...

  2. Behaviors of cost functions in image registration between 201Tl brain tumor single-photon emission computed tomography and magnetic resonance images

    International Nuclear Information System (INIS)

    We studied the behaviors of cost functions in the registration of thallium-201 (201Tl) brain tumor single-photon emission computed tomography (SPECT) and magnetic resonance (MR) images, as the similarity index of image positioning. A marker for image registration [technetium-99m (99mTc) point source] was attached at three sites on the heads of 13 patients with brain tumor, from whom 42 sets of 99mTc-201Tl SPECT (the dual-isotope acquisition) and MR images were obtained. The 201Tl SPECT and MR images were manually registered according to the markers. From the positions where the two images were registered, the position of the 201Tl SPECT was moved to examine the behaviors of the three cost functions, i.e., ratio image uniformity (RIU), mutual information (MI), and normalized MI (NMI). The cost functions MI and NMI reached the maximum at positions adjacent to those where the SPECT and MR images were manually registered. As for the accuracy of image registration in terms of the cost functions MI and NMI, on average, the images were accurately registered within 3 deg of rotation around the X-, Y-, and Z-axes, and within 1.5 mm (within 2 pixels), 3 mm (within 3 pixels), and 4 mm (within 1 slice) of translation to the X-, Y-, and Z-axes, respectively. In terms of rotation around the Z-axis, the cost function RIU reached the minimum at positions where the manual registration of the two images was substantially inadequate. The MI and NMI were suitable cost functions in the registration of 201Tl SPECT and MR images. The behavior of the RIU, in contrast, was unstable, being unsuitable as an index of image registration. (author)

  3. Normal 201Tl SPECT myocardial scintigram - a basis for quantification of tomographic data using 1800 rotation

    International Nuclear Information System (INIS)

    Using 1800 rotation for 201Tl myocardial perfusion SPECT the influence of different myocardial wall thickness, depth-dependent resolution, attenuation and other facts is the reason for about 30% inhomogenity from anterolateral to posteroseptal myocardium in polar coordinate Bull's eye. It is very difficult for a visual observer to assess patients without knowledge of the corresponding normal distribution. We studied 25 normal males and calculated pixelwice vitality, washout rate between stress, 2-hr and 3.5-hr delay to obtain a normal Bull's eye reference databank. Before the patient's data can be analysed it is necessary to multiplicate them with the inverse normal Bull's eye. (author)

  4. Gamma radiation measurements and Monte Carlo computations following myocardial perfusion imaging with 201Tl

    International Nuclear Information System (INIS)

    In the current study, the time-dependent retention of 201Tl-thallous chloride (111 MBq) was measured in a 56-y-old man undergoing myocardial perfusion imaging. For 23 d following the 201Tl injection, total-body retained activity was measured by (i) in situ gamma spectrometry using a portable high-purity germanium (HPGe) detector and (ii) ex vivo urine radioassay using a shielded HPGe detector. The time-dependent decrease in total-body activity followed a monoexponential function, exp(-0.011 t), with an excellent correlation (R2=0.9988) between the experimental data and the fitted values. The effective half-life, Teff, of 201Tl (physical half-life, Tph: 72.9 h) was therefore 63 h and the biological half-life, Tb, 463 h=19.3 d, identical to those measured in the same patient in 1997 (i.e. 14 y ago). The time-dependent decrease in the urine activity concentration, which followed a monoexponential function, exp(-0.0115 t), corroborated the foregoing results. The correlation (R2=0.9939) between the experimental data and the fitted values was again excellent. The effective half-life, Teff, was 60.26 h and the biological half-life, Tb, 348 h = 14.5 d. Monte Carlo simulation using a simple model of the patient as a unit-density cylinder filled with water and containing a uniform distribution of 201Tl yielded photon flux results in reasonable agreement with the measured data. (authors)

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

    International Nuclear Information System (INIS)

    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 ?g/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)

  6. Clinical evaluation of {sup 201}Tl single photon emission computed tomography in patients with large opacities due to silicosis and in those with bronchogenic carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Sunami, Koji; Kishimoto, Takumi; Yonei, Toshiro; Ozaki, Shinji; Kimura, Kazuhi; Fujioka, Hideki; Ohke, Masashi; Ohnoshi, Taisuke [Okayama Rousai Hospital (Japan)

    1996-06-01

    {sup 201}Tl single photon emission computed tomography ({sup 201}Tl SPECT) was used to evaluate 18 patients with large opacities due to silicosis and 22 others with bronchogenic carcinoma. An early scan and a delayed scan were obtained and the retention index was calculated from the early ratio and the delayed ratio. In patients with silicosis, the retention index and the two ratios were significantly lower than in the patients with bronchogenic carcinoma (p<0.01). In patients with stable shadows on chest X-ray films due to large opacities of silicosis, the delayed ratio was the same as or lower than the early ratio. However, in patients with silicosis who had high activity in large opacities, the delayed ratio was higher than the early ratio. These results suggest that {sup 201}Tl SPECT is useful for evaluating the activity of large opacities in patients with silicosis and for differentiating large opacities caused by silicosis from those caused by bronchogenic carcinoma. (author)

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

    International Nuclear Information System (INIS)

    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)

  8. Effects of metabolically ischemic, but viable, myocardium on QT dispersion in patients with acute myocardial infarction. A study with resting I-123-BMIPP/thallium-201 myocardial single-photon emission computed tomography

    International Nuclear Information System (INIS)

    In chronic Q-wave myocardial infarction, QT dispersion is closely correlated with infarct size, but this correlation has not been evaluated for acute myocardial infarction (AMI). The effects of abnormal fatty acid metabolism on QT dispersion were examined in 123 patients with AMI who underwent resting iodine-123-15-iodophenyl 3-methyl pentadecanoic acid (BMIPP)/thallium-201 (201Tl) myocardial single photon emission computed tomography (SPECT) and electrocardiographic analysis in the subacute phase. The relationship between BMIPP and 201Tl was defined as match when the total defect score for BMIPP was equal to or smaller than that for 201Tl, and as mismatch when the total defect score for BMIPP was larger than that for 201Tl. Twenty-six patients (21%) demonstrated BMIPP-201Tl match and 97 (79%) demonstrated mismatch. Infarct size was closely correlated with QT dispersion (r=0.67, p201Tl match, but weakly correlated (r=0.30, p201Tl mismatch. For small infarctions, QT dispersion was significantly larger in patients with BMIPP-201Tl mismatch than in those with BMIPP-201Tl match (62±24 ms vs 41±18 ms, p=0.03), but did not differ between the 2 groups for large infarctions. This study shows that QT dispersion is influenced by infarct size and by the presence of metabolically ischemic but viable myocardium in patients with AMI. (author)

  9. Absolute quantitation of myocardial blood flow with 201Tl and dynamic SPECT in canine: optimisation and validation of kinetic modelling

    International Nuclear Information System (INIS)

    201Tl has been extensively used for myocardial perfusion and viability assessment. Unlike 99mTc-labelled agents, such as 99mTc-sestamibi and 99mTc-tetrofosmine, the regional concentration of 201Tl varies with time. This study is intended to validate a kinetic modelling approach for in vivo quantitative estimation of regional myocardial blood flow (MBF) and volume of distribution of 201Tl using dynamic SPECT. Dynamic SPECT was carried out on 20 normal canines after the intravenous administration of 201Tl using a commercial SPECT system. Seven animals were studied at rest, nine during adenosine infusion, and four after beta-blocker administration. Quantitative images were reconstructed with a previously validated technique, employing OS-EM with attenuation-correction, and transmission-dependent convolution subtraction scatter correction. Measured regional time-activity curves in myocardial segments were fitted to two- and three-compartment models. Regional MBF was defined as the influx rate constant (K1) with corrections for the partial volume effect, haematocrit and limited first-pass extraction fraction, and was compared with that determined from radio-labelled microspheres experiments. Regional time-activity curves responded well to pharmacological stress. Quantitative MBF values were higher with adenosine and decreased after beta-blocker compared to a resting condition. MBFs obtained with SPECT (MBFSPECT) correlated well with the MBF values obtained by the radio-labelled microspheres (MBFMS) (MBFSPECT = -0.067 + 1.042 x MBFMS, p 201Tl and dynamic SPECT. (orig.)

  10. Myocardial scintigraphic studies with 123I-MIBG, 201Tl and 99mTc-PYP in patients with cardiac amyloidosis

    International Nuclear Information System (INIS)

    Myocardial scintigraphic studies, using 123I-metaiodobenzylguanidine (MIBG), 99mTc-pyrophosphate (PYP) and 201Tl were performed in 4 patients with cardiac amyloidosis. In MIBG myocardial images, 2 patients with familial amyloid polyneuropathy (FAP) showed complete or partial defect and the other 2 with primary amyloidosis had normal myocardial uptake of MIBG. In PYP myocardial images, diffuse myocardial uptake of PYP was mild in 2 patients with FAP and moderate in the other 2. 201Tl myocardial images revealed normal myocardial uptake of 201Tl in 2 patients with FAP and 1 with primary amyloidosis, and intense myocardial uptake in the other one with primary amyloidosis. These results suggest that myocardial scintigraphies with PYP and 201Tl may be useful for the detection of cardiac amyloidosis and estimation of its pathophysiology. And MIBG myocardial scintigraphy may provide useful information about sympathetic nerve abnormalities which vary with type of the fibril protein, clinical syndromes and disease process of cardiac amyloidosis. (author)

  11. Influence of increased 201Tl lung uptake on the myocardial viability of the patients with dilated cardiomyopathy under congestive heart failure

    International Nuclear Information System (INIS)

    Influence of increased 201Tl lung uptake on the myocardial viability was studied in 15 patients with dilated cardiomyopathy under congestive heart failure. Rest and 4 hours delayed 201Tl SPECT were obtained. At the same time anterior planar images were collected. In 10 patients of 15 patients 201Tl lung heart ratio in SPECT (LHR) was larger than that in planar images. Maximal 201Tl lung uptake was noted at the lower left lung adjacent to the heart. In the delayed images 201Tl lung uptake diminished. In 10 patients the value of LHR in the delayed images was less than 0.5. By comparing initial images with delayed images it was proved to be difficult to determine the myocardial margin adjacent to the increased 201Tl lung uptake. In 2 patients lateral defects were concealed by the increased 201Tl lung uptake. In the remaining patients lateral wall was similar to the hypertrophic myocardium. The effect of scatter due to the increased 201Tl lung uptake was noted in the neighboring myocardium. In most cases %201Tl uptake in the septum was relatively depressed by increased %201Tl uptake in the lateral wall. In the delayed images pseudo-redistribution was noted in the septum. Mean value of differences in %201Tl uptake between initial and delayed images was 8(2-15)%. It was concluded that in case of increased 201Tl lung uptake SPECT could not accurately estimate myocardial viability by initial images and delayed images were necessary for precise estimation. (author)

  12. Study of washout rate in patients with chronic renal failure by dipyridamole 201Tl myocardial scintigraphy

    International Nuclear Information System (INIS)

    Fourteen patients with chronic renal failure (CRF) were studied by dipyridamole 201Tl myocardial scintigraphy. In this study, patients with coronary heart disease were excluded by clinical findings. 201Tl SPECT was performed at 8 min after injection of dipyridamole (0.56 mg/kg) and at a 3-hr delayed interval, and washout rates (WR) were calculated. Because UCG showed left ventricular hypertrophy (thickness; 13±2 mm) in CRF, the WR values were compared with those of hypertrophic cardiomyopathy (HCM)(n=9). In CRF, an average WR was 54.2±6.8% and was significantly higher than that in normal (46.2±9.1%, p<0.05, n=9), though WR in HCM was significantly low (26.9±11.4%, p<0.01). Hematocrit value was 24.5±3.2% in CRF and was significantly lower than that in normal (37.8±3.6%, p<0.001). On the other hand, hemoconcentration was observed in HCM (hematocrit; 44.6±3.6%, p<0.001). WR in CRF, HCM and normal had significant correlation with hematocrit values (r=-0.796, p<0.001). These results suggest that anemia or hemoconcentration may affect coronary blood flow and WR, and this should be considered when diagnosing coronary heart disease in CRF or HCM. (author)

  13. Myocardial imaging with 201Tl: an analysis of clinical usefulness based on Bayes' theorem

    International Nuclear Information System (INIS)

    Rest-exercise thallium-201 (201Tl) myocardial imaging and rest-exercise electrocardiography were performed in 137 patients with suspected coronary artery disease (CAD). The final diagnosis of coronary disease was made by arteriography. Sensitivity and specificity for the ECG and thallium studies alone or combined were then determined. Based on these data, the posttest probability of CAD with a normal or abnormal test was calculated using Bayes' theorem for disease prevalences ranging from 1% to 99%. The difference between the probability of disease with a normal test and the probability of disease with an abnormal test was also calculated for each prevalence range. The results demonstrate that 201Tl imaging discriminates between disease absence or presence better than does the ECG. However, both the ECG and thallium studies provide rather poor discrimination between disease and no disease when the disease prevalence is low (less than 0.20) or high (greater than 0.70). Because of this characteristic, it is unlikely that screening tests for CAD will prove useful unless the disease prevalence in the group under study is in the moderate (0.20 to 0.70) range

  14. Myocardial imaging with 201Tl at rest and during exercise. Comparison with coronary arteriography and resting and stress electrocardiography

    International Nuclear Information System (INIS)

    Myocardial imaging with intravenous thallium-201 (201Tl) was performed at rest and following maximal treadmill exercise in 101 patients with suspected coronary artery disease. Results were interpreted from Polaroid scintiphotos by three independent observers with complete interobserver agreement in 79%. Of 25 patients with no or insignificant coronary artery disease (201Tl image defect, one (4%) had an exercise 201Tl defect, none had an ECG Q wave, and four (16%) had exercise ST-segment depression. Among 76 patients with coronary artery disease (greater than or equal to 50% diameter stenosis), 58 (76%) had a defect on either the rest or exercise 201Tl image. The proportion of patients with an exercise image defect (50/76, 66%) was greater than the proportion with exercise ST depression alone (34/76, 45%; P 201Tl is easily accomplished with readily available imaging equipment. The image data enhanced the diagnostic sensitivity of stress electrocardiography, and provided spatial identification of the abnormal segment(s) of myocardium

  15. Myocardial scintigraphy with 201Tl in combination with pharmacological tests in the diagnosis of coronary heart diseases

    International Nuclear Information System (INIS)

    The paper presents the results from examination of 67 patients with coronary heart disease verified by a bicycle ergometric tests, 48 underwent 201Tl myocardial scintigraphy along with a dipyridamole test, 19, the scintigraphy in combination with an isoproterenol test. The feasibilities of employing the procedures in the diagnosis of coronary heart disease were compared by statistic analysis

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

    International Nuclear Information System (INIS)

    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 the influence of the judgement of defect, and provide higher resolution of images, the authors recommend +-10% 201Tl energy window for 201Tl/99Tcm simultaneous acquisition

  17. Noninvasive detection and localization of coronary stenoses in patients: comparison of resting dipyridamole and exercise 201Tl myocardial perfusion imaging

    International Nuclear Information System (INIS)

    Two noninvasive tests to detect and localize coronary stenoses were compared in a fully blinded protocol. 201Tl myocardial perfusion imaging (MPI) following maximal treadmill exercise and pharmacologic coronary vasodilation with intravenous dipyridamole (DP) was performed in 33 patients. 201Tl imaging defects in six myocardial perfusion regions were correlated with stenoses in their respective vascular distributions. Disease severity was determined with coronary arteriograms using a computer-assisted method. 198 myocardial regions were evaluated; 101 were supplied by at least one major artery with a greater than or equal to 50% stenosis (luminal diameter narrowing). The sensitivity and specificity for detecting a greater than or equal to 50% stenosis were 85% and 64% (p less than 0.005), respectively, for DP and 84% and 68% (p less than 0.005) for exercise-201Tl imaging. A particular combination of anterior and septal imaging defects was useful in detecting left anterior descending artery stenoses proximal to its first septal branch. DP administration was safe in this group of patients; however, 42% experienced transient chest pain. Although the overall sensitivity and specificity of the two methods were not significantly different, DP-MPI appeared more sensitive than exercise-MPI (70% vs 52%, p less than 0.01) in detecting coronary stenoses in the 40% to 60% range. DP-201Tl MPI provides a useful alternative test for potential coronary disease patients unable to perform maximal exercise

  18. Specific perfusion pattern in stress 201Tl myocardial scintigraphy of left main coronary artery disease

    International Nuclear Information System (INIS)

    The usefulness of stress 201Tl myocardial scintigraphy for identifying left main coronary artery disease was evaluated with data from 23 patients with 50% or more narrowing of the left main coronary artery and 56 patients with 75% or more narrowing of the major coronary arteries but without left main coronary artery involvement (no left main coronary artery disease). Quantitative evaluation of stress perfusion scintigrams in all five patients with narrowing of the left main coronary artery of 90% or more showed a characteristic perfusion pattern (left main pattern) of extensive homogeneous defect over the whole anterolateral segment and simultaneous defects in all radii of the high anteroseptal and high posterolateral segments. On the other hand, such a perfusion pattern was noted in only 1 of 18 patients with less than 90% stenosis of the left main coronary artery and in only 1 of 56 patients with no left coronary artery disease. (orig.)

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

    International Nuclear Information System (INIS)

    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.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Hiroshi; Misawa, Toshihiro; Kutsumi, Yasunori (Fukui Medical School, Matsuoka (Japan)) (and others)

    1991-01-01

    To determine quantitatively the discriminant and characteristics of cor pulmonale, {sup 201}Tl 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 (PaCO{sub 2}), while it was inversely correlated with arterial oxygen tension (PaO{sub 2}). However, there was no significant correlation between Tl-score and mPAP, TPR, PaCO{sub 2}, and PaO{sub 2} 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 {sup 201}Tl 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.).

  1. Noninvasive detection of regional myocardial perfusion abnormality with 201Tl and 81Rb

    International Nuclear Information System (INIS)

    Myocardial scintigrams were performed at rest and during exercise using 201Tl and 81Rb. Patients underwent graded ergometer exercise stress tests. In normals, myocardial images were horse-shoe of O-shaped and concentration of radionuclide was relatively uniform throughout the myocardium. In 13 patients with old myocardial infarctions, and abnormal Q waves, regional myocardial perfusion defects (cold area) were detected. Their locations correlated with sites of the abnormal Q waves. Two patients had no abnormal Q waves at the examination, but their scintigrams showed cold areas, the locations of which coincided with coronary angiographic findings. Exercise stress Ecg and stress scintigrams were performed. Myocardial perfusion defects, which developed from exercise stress, were detected in 9 of 10 positive exercise Ecg patients, 2 of 4 equivocal exercise Ecg patients, and 2 of 10 negative exercise Ecg patients. These 2 patients (exercise Ecg (-), stress scintigram (+)) had typical angina. Findings of exercise stress scintigrams coincided better with clinical findings than did those of exercise Ecg. These scintigraphic methods appear to be excellent for detection of noninvasive coronary heart disease noninvasively. (Evans, J.)

  2. Quantitative assessment of the infarct size with the unfolded map method of 201Tl myocardial SPECT in patient with acute myocardial infarction

    International Nuclear Information System (INIS)

    The unfolded map method of 201Tl single photon emission computed tomography (SPECT) was evaluated as to the ability to quantify and the clinical reliability in estimation of infarct size. The following results were obtained from basic experiments using a thoracic phantom. The defect area estimated by the unfolded map method was well correlated with the real defect area, in spite of overestimation of the defect area, when the defect area was determined by an isocount method (below 80% of maximum count) (y=1.941 + 2.292x, r=0.971). The defect volume estimated by short-axis images of 201Tl SPECT was closely correlated with real defect volume in spite of overestimation of defect volume (y=0.762 + 2.156x, r=0.982). When the defect area was estimated by division of the defect volume by the mean myocardial compartment thickness, it was closely correlated with real defect area (y=0.946 + 1.232x, r=0.990). When the volume was calculated from the summation of voxels in the regions districted by isocount threshold level at each section of the 99mTc SPECT, the optimal isocount threshold level (percentage to maximum count) was 55%. Then, the clinical reliability of the unfolded map method as infarct sizing was evaluated in 26 patients with acute myocardial infarction by comparing it with enzymatic method, Bull's eye method, and 99mTc pyrophosphate (PYP) SPECT method. In 14 first attack patients without right ventricular infarction, infarct area (IA) of the unfolded map method correlated most closely with the accumulated creatine kinase MB isoenzyme release (CK-MBr) (r=0.897), compared with the extent score (ES) (r=0.853) and the severity score (SS) (r=0.871) of Bull's eye method and the infarct volume (IV) (r=0.595) of 99mTc PYP SPECT. In conclusion, although the unfolded map method of 201Tl SPECT has the tendency for overestimating infarct size, it is accurate and clinically reliable in estimating infarct size. (author)

  3. Effects of diltiazem in patients with ischemic heart disease evaluation by exercise stress test and 201Tl myocardial scintigraphy

    International Nuclear Information System (INIS)

    In 15 ischemic heart disease patients including 6 with myocardial infarction, the effect of Diltiazem, a Ca-antagonist, was evaluated by exercise stress tests using an ergometer and by exercise stress 201Tl myocardial scintigraphy. Administration of Diltiazem significantly increased the exercise tolerance time from 6.6 +- 3.3 min. to 8.5 +- 3.2 min. (p 0.01). During exercise stress, heart rate was significantly decreased below the level of the controls and rate-pressure product, which is considered to be oxygen consumption index, was also decreased, while no significant change occurred in systolic pressure. Exercise stress 201Tl myocardial scintigraphy revealed some improvement of the defect in 5 of 8 cases. (Ueda, J.)

  4. 201-Tl myocardial scintigraphy using SPECT. Clinical evaluation based on the Bayes' theorem

    International Nuclear Information System (INIS)

    The results of 201-Tl myocardial scintigraphy using SPECT were analyzed by means of the Bayes' theorem with respect to the positive and negative predictive value. A first evaluation was performed on a case by case basis with respect to the decision coronary heart disease (CHD) yes or no comprising the total number of patients. Furthermore two subgroups were formed a) patients with myocardial infarction or b) without. In the second part segmental findings of the leftventricular myocardium were analyzed applying the same subdivision. The values of the post-test-probability were calculated and plotted as a function of 2 parameters: 1) the pre-test-probability and 2) the outcome of the test. The maximum of the probability-difference-curve and thus the highest gain in diagnostic information was achieved with positive test results for medium pre-test-probability (about 50%). A prefered application of myocardial scintigraphy using SPECT therefore is the diagnosis of patients with a medium pre-test-probability of CHD as well as therapy planning and follow-up. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

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

    International Nuclear Information System (INIS)

    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

  7. Value of myocardial 201Tl scintigraphy for the diagnosis of coronary heart disease in patients with blocked left peduncle of His' bundle

    International Nuclear Information System (INIS)

    Possible use of loading myocardial 201Tl scintigraphy is considered for patients with blocked left peduncle of His' bundle. The procedure is shown to be of considerable value for the prognosis of coronary heart disease in such patients

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

    DEFF Research Database (Denmark)

    Charabi, Samih Ahmed; Lassen, N A

    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. The relative tracer concentration and uptake were correlated to tumor volume determined by gadolinium DTPA enhanced MR, to prediagnostic duration of symptoms, to tumor vascularity expressed by the average number of intratumoral vessels using the endothelial marker CD31, and to the proliferative activity in the tumors expressed by positive staining with the monoclonal antibody MIB-1 for Ki-67. A positive 201TI enhancement was detected in 17 tumors (n = 17). Tumors U and C were statistically unrelated to tumor volume (p = 0.236 and p = 0.439). SPECT demonstrated all tumors > 0.8 cm3, but it had its limitation as a diagnostic modality of small intracanalicular tumors, when compared with gadolinium DTPA enhanced MR. Relating U and C in all tumors (n = 29) and the prospectively registered data on the prediagnostic duration of symptoms, a statistical significance was found (p = 0.012 and p = 0.015). No statistically significant correlation was observed between U and C and the proliferative activity of the tumors expressed by positive staining with the monoclonal antibody MIB-1 for Ki-67 (p = 0.063 and p = 0.086). A statistically significant correlation was noted between C and U in the operated group (n = 12) and tumor vascularity expressed by the average number of the intratumoral vessels (p = 0.003 and p = 0.014). SPECT was found to be superior to MR in determining VS growth potentials as it expresses tumor vascularity, which is essential for tumor growth. It seems that we now have an in vivo functional radiological modality capable of providing data on VS vascularity and determination of growth potential in the individual tumor. A high radioactive tracer uptake in the tumor corresponded to high tumor vascularity, indicating a high growth rate and vice versa.

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

    International Nuclear Information System (INIS)

    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)

  10. 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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  11. Evaluation of myocardial perfusion and left ventricular function by 201Tl scintigraphy after dipyridamole

    International Nuclear Information System (INIS)

    201Tl myocardial imaging was performed at rest and after dipyridamole (0.44 mg/kg) on 50 patients with known or suspected ischemic heart disease. The dipyridamole had no effect in 14 patients (group Dip.0). In 17 patients (group Dip +-) it significantly modified the contrast of the rest image (by increasing or decreasing a rest perfusion defect). In 19 patients (group Dip - Steal) the drug induced a paradoxical response interpreted as a coronary steal effect (an active region at rest becomes hypoactive after dipyridamole while an underperfused region at rest improves). All patients underwent coronary arteriography and left monoplane ventriculography; results were interpreted in relation to these angiographic data. The mean percentage of stenoses (per patient) was about the same in the three groups but it was found that, despite these stenoses, the patients of the group Dip - Steal had a good left ventricular function (EF = 0.62 +- 0.12). On the other hand, the ejection fraction was very poor in the two other groups (0.50 +- 0.17 and 0.48 +- 0.17). Moreover it was found that: (1) the frequency of high grade or even complete obstruction was notably less in group Dip - Steal (P < 0.05); (2) the frequency of angiographically visible collaterals was higher in group Dip - Steal (P < 0.05); (3) the left anterior descending artery was less diseased than the right coronary artery in group Dip - Steal (P < 0.05). These results have a real prognostic value for the assessment of the preserved cardiac performance in Dip - Steal patients despite severe stenoses, and are discussed in terms of compensatory collateral circulation and preservation of the coronary-flow reserve in the myocardium distal to a critical stenosis. (orig.)

  12. Low-dose single acquisition rest {sup 99m}Tc/stress {sup 201}Tl myocardial perfusion SPECT protocol: phantom studies and clinical validation

    Energy Technology Data Exchange (ETDEWEB)

    Dey, Thomas [RWTH Aachen University, Institute of Imaging and Computer Vision, Aachen (Germany); Backus, Barbra E.; Romijn, R.Leo [St. Antonius Hospital, Department of Nuclear Medicine, Nieuwegein (Netherlands); Wieczorek, Herfried [Philips Research, Eindhoven (Netherlands); Verzijlbergen, J.F. [St. Antonius Hospital, Department of Nuclear Medicine, Nieuwegein (Netherlands); Erasmus Medical Center, Department of Nuclear Medicine, Rotterdam (Netherlands)

    2014-03-15

    We developed and tested a single acquisition rest {sup 99m}Tc-sestamibi/stress {sup 201}Tl dual isotope protocol (SDI) with the intention of improving the clinical workflow and patient comfort of myocardial perfusion single photon emission computed tomography (SPECT). The technical feasibility of SDI was evaluated by a series of anthropomorphic phantom studies on a standard SPECT camera. The attenuation map was created by a moving transmission line source. Iterative reconstruction including attenuation correction, resolution recovery and Monte Carlo simulation of scatter was used for simultaneous reconstruction of dual tracer distribution. For clinical evaluation, patient studies were compared to stress {sup 99m}Tc and rest {sup 99m}Tc reference images acquired in a 2-day protocol. Clinical follow-up examinations like coronary angiography (CAG) and fractional flow reserve (FFR) were included in the assessment if available. Phantom studies demonstrated the technical feasibility of SDI. Artificial lesions inserted in the phantom mimicking ischaemia could be clearly identified. In 51/53 patients, the image quality was adequate for clinical evaluation. For the remaining two obese patients with body mass index > 32 the injected {sup 201}Tl dose of 74 MBq was insufficient for clinical assessment. In answer to this the {sup 201}Tl dose was adapted for obese patients in the rest of the study. In 31 patients, SDI and {sup 99m}Tc reference images resulted in equivalent clinical assessment. Significant differences were found in 20 patients. In 18 of these 20 patients additional examinations were available. In 15 patients the diagnosis based on the SDI images was confirmed by the results of CAG or FFR. In these patients the SDI images were more accurate than the {sup 99m}Tc reference study. In three patients minor ischaemic lesions were detected by SDI but were not confirmed by CAG. In one of these cases this was probably caused by pronounced apical thinning. For two patients no relevant clinical follow-up information was available for evaluation. The proposed SDI protocol has the potential to improve clinical workflow and patient comfort and suggests improved accuracy as demonstrated in the clinical feasibility study. (orig.)

  13. Low-dose single acquisition rest 99mTc/stress 201Tl myocardial perfusion SPECT protocol: phantom studies and clinical validation

    International Nuclear Information System (INIS)

    We developed and tested a single acquisition rest 99mTc-sestamibi/stress 201Tl dual isotope protocol (SDI) with the intention of improving the clinical workflow and patient comfort of myocardial perfusion single photon emission computed tomography (SPECT). The technical feasibility of SDI was evaluated by a series of anthropomorphic phantom studies on a standard SPECT camera. The attenuation map was created by a moving transmission line source. Iterative reconstruction including attenuation correction, resolution recovery and Monte Carlo simulation of scatter was used for simultaneous reconstruction of dual tracer distribution. For clinical evaluation, patient studies were compared to stress 99mTc and rest 99mTc reference images acquired in a 2-day protocol. Clinical follow-up examinations like coronary angiography (CAG) and fractional flow reserve (FFR) were included in the assessment if available. Phantom studies demonstrated the technical feasibility of SDI. Artificial lesions inserted in the phantom mimicking ischaemia could be clearly identified. In 51/53 patients, the image quality was adequate for clinical evaluation. For the remaining two obese patients with body mass index > 32 the injected 201Tl dose of 74 MBq was insufficient for clinical assessment. In answer to this the 201Tl dose was adapted for obese patients in the rest of the study. In 31 patients, SDI and 99mTc reference images resulted in equivalent clinical assessment. Significant differences were found in 20 patients. In 18 of these 20 patients additional examinations were available. In 15 patients the diagnosis based on the SDI images was confirmed by the results of CAG or FFR. In these patients the SDI images were more accurate than the 99mTc reference study. In three patients minor ischaemic lesions were detected by SDI but were not confirmed by CAG. In one of these cases this was probably caused by pronounced apical thinning. For two patients no relevant clinical follow-up information was available for evaluation. The proposed SDI protocol has the potential to improve clinical workflow and patient comfort and suggests improved accuracy as demonstrated in the clinical feasibility study. (orig.)

  14. Comparison of adenosine stress and exercise stress 201Tl myocardial perfusion imaging for diagnosis of coronary heart disease

    International Nuclear Information System (INIS)

    Objective: The aim of this study was to compare the diagnostic values of adenosine and exercise stress 201Tl myocardial perfusion imaging for detecting coronary heart disease (CHD). Methods: 41 patients with suspected CHD were randomly divided into two groups. In one group adenosine stress was submitted, the exercise stress myocardial SPECT was performed in another. Coronary angiography (CAG) was performed in each patient within 2 weeks before or after SPECT. The result of CAG was taken as 'gold standard of CHD. They compared the diagnostic value of two methods. Results: In adenosine group, the sensitivity, specificity, positive predictive value, negative predictive value, accuracy are 92.86%, 57.14%, 81.25%, 80.00%, 80.95% respectively. In exercise stress group, are 100%, 60.0%, 71.43%, 100%, 80.00% respectively. Detection rates of coronary artery lesions were 66.67% and 72.22% in two groups respectively. Conclusion Adenosine stress testing and exercise stress testing 201Tl myocardial perfusion imaging may provide similar value for detection of CHD. (authors)

  15. Nitrate administration to enhance the detection of myocardial viability by technetium-99m tetrofosmin single-photon emission tomography

    International Nuclear Information System (INIS)

    A comparison was performed between technetium-99m tetrofosmin myocardial perfusion tomography at baseline and after nitrate administration, using a 2-day protocol, and rest-reinjection thallium-201 single-photon emission tomography (SPET) studies in order to assess whether nitrates enhance the detection of viable myocardium with 99mTc-tetrofosmin. Fifteen patients with coronary artery disease, previous myocardial infarction and a left ventricular ejection fraction 201Tl rest-injection and 99mTc-tetrofosmin baseline-postnitroglycerin (0.4 mg sublingually) SPET studies, within 48 h. Tomograms based on the three spatial planes were divided into 15 segments and regional tracer uptake was quantitatively analysed. Viability was defined as presence of tracer uptake ≥50% of peak activity on baseline studies or after reversibility. The percentage of peak activity of 99mTc-tetrofosmin at baseline correlated with that of 201Tl (r=0.82, P 99mTc-tetrofosmin studies, 73 of the 225 segments that were analysed had 99mTc-tetrofosmin uptake from 40%±9% to 57%±9% of peak activity (P=0.003). All reversible segments after nitrate administration had viability criteria on 201Tl studies, but 20 segments that were non-viable on 99mTc-tetrofosmin studies were viable on 201Tl studies. Using a threshold value of ≥40% of peak activity, only seven segments remained non-viable on 99mTc-tetrofosmin studies. Overall agreement between 99mTc-tetrofosmin with nitrates and 201Tl-reinjection regarding the presence of myocardial viability was 90%. Detection of myocardial viability with 99mTc-tetrofosmin was enhanced after nitrate administration, correlating with viability criteria observed on thallium studies. (orig.). With 4 figs., 3 tabs

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

    International Nuclear Information System (INIS)

    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

  17. Comparison of correction techniques for simultaneous {sup 201}Tl/{sup 99m}Tc myocardial perfusion SPECT imaging: a dog study

    Energy Technology Data Exchange (ETDEWEB)

    Knesaurek, Karin; Machac, Josef [Division of Nuclear Medicine, The Mount Sinai Medical Center, New York (United States)

    2000-11-01

    We compared two correction methods for simultaneous {sup 201}Tl/{sup 99m}Tc dual-isotope single-photon emission computed tomography (SPECT). Both approaches use the information from the third energy window placed between the photopeak windows of the {sup 201}Tl and {sup 99m}Tc. The first approach, described by Moore et al, corrects only for the contribution of the {sup 99m}Tc to the {sup 201}Tl primary 70 keV window. We developed the three-window transformation dual-isotope correction method, which is a simultaneous cross-talk correction. The two correction methods were compared in a simultaneous {sup 201}Tl/{sup 99m}Tc sestamibi cardiac dog study. Three separate acquisitions were performed in this dog study: two single-isotope and one dual-isotope acquisition. The {sup 201}Tl single-isotope images were used as references. The total number of counts, and the contrast between the left ventricular cavity (LVC) and the myocardium, were used in 70 keV short-axis slices as parameters for evaluating the results of the dual-isotope correction methods. Three consecutive short-axis slices were used to calculate averaged contrast and the averaged total number of counts. The total number of the counts was 667 000 {+-} 500 and 414 500 {+-} 400 counts for the dual-isotope ({sup 201}Tl + {sup 99m}Tc) and single-isotope ({sup 201}Tl-only) 70 keV images, respectively. The corrected dual-isotope images had 514 700 {+-} 700 and 368 000 {+-} 600 counts for Moore's correction and our approach, respectively. Moore's method improved contrast in the dual-isotope 70 keV image to 0.14 {+-} 0.03 from 0.11 {+-} 0.02, which was the value in the 70 keV non-corrected dual-isotope image. Our method improved the same contrast to 0.22 {+-} 0.03. The contrast in the {sup 201}Tl single-isotope 70 keV image was 0.28 {+-} 0.02. Both methods improved the 70 keV dual-isotope images. However, our approach provided slightly better images than Moore's correction when compared with {sup 201}Tl-only 70 keV images. (author)

  18. Assessment of myocardial viability by exercise stress myocardial tomography with 201Tl

    International Nuclear Information System (INIS)

    Exercise stress (Ex) and redistribution (RD) myocardial tomography with Tl-201 has been widely used for evaluating myocardial viability. But recent studies have demonstrated that reinjection (ReI) study following RD study is necessary for detecting reversible ischemic myocardium. On the other hand, decreased myocardial washout of Tl-201 after Ex is an indicator of myocardial ischemia. So we have studied the usefulness of myocardial Tl-201 washout rate (WOR) for the evaluation of myocardial viability by comparing it with ReI images. Ex and RD myocardial tomographies were obtained immediately after Ex and 3 hours later. After RD study a small amount of Tl-201 was injected and ReI imaging was repeated. We studied 64 myocardial segments (in 58 patients with coronary artery disease) in which Ex-induced perfusion defects persisted in RD images. According to the changes of perfusion defects between Ex, RD and ReI images, they were classified into 3 types: Type I; perfusion defect on the RD image was identical to ReI image (75%). Type I was divided into 2 subgroups whether perfusion defect at Ex was unchanged (Ia, 42%) or improved (Ib, 33%) on the RD image. Type II; perfusion defect at Ex was reduced on the RD image and it improved furthermore at ReI image (17%). Type III; perfusion defect was the same at Ex and RD but it was reduced on the ReI image (8%). WOR less than 30% was defined as abnormal when Ex heart rate exceeded 120 bpm and lung-myocardial Tl-201 uptake ratio was less than 0.45. The differentiation between Type Ia and Type III is of great importance. History of myocardial infarction, effort angina and Ex induced ST depression could not differentiate these 2 groups. WOR abnormality was observed in all of Type III, but WOR was normal in Type Ia. In conclusion, WOR abnormality in Ex-RD myocardial imaging is useful for evaluating myocardial viability. ReI imaging is necessary for the precise evaluation of viable muscle mass and for inadequate Ex. (author)

  19. Myocardial gammagraphy with 201Tl chloride in diagnosis of ischaemic heart disease

    International Nuclear Information System (INIS)

    In a group of 60 patients, the diagnostic reliability was compared of perfusion gammagraphy of the heart muscle with 201Tl chloride at exercise and of the ECG exercise test, with that of X-ray coronarography as the standard diagnostic method for ischaemic heart disease. The method of thallium perfusion gammagraphy of the heart muscle was as to its effectiveness very close to the method of standard diagnosis and its results in the diagnosis of ischaemic heart disease were significantly better than the results of the ECG exercise test. (author)

  20. Comparative study of adenosine and exercise 201Tl myocardial perfusion tomographic imaging for detection of coronary heart disease

    International Nuclear Information System (INIS)

    To compare diagnostic accuracy of adenosine and exercise 201Tl myocardial perfusion tomographic imaging for detection of coronary heart disease (CHD) in patients with a normal rest ECG and no history of myocardial infarction, 81 patients with CHD and 10 normal control subjects underwent adenosine myocardial perfusion imaging, exercise nuclide myocardial perfusion imaging was performed in 117 patients with CHD and 16 normal control subjects, two groups also had coronary arteriography. Both exercise and adenosine testing parameters were analysed. It is shown: 1) The sensitivity and specificity for detection of CHD were 79% vs 80% for adenosine group and 81% vs 81% for exercise myocardial perfusion imaging group respectively. There was no significant difference in comparison with two matched groups (?2 = 1.13, ?2 = 0.18, ?2 = 0.12, P>0.05). 2) Side effects induced by adenosine accounted for 89% of patients, all symptoms were mild and disappeared quickly after the termination of the study except in 2 cases withdrawal of infusion needed because of severe angina pectoris. Adenosine myocardial perfusion imaging is a safe and sensitive method for detection of CHD. The diagnostic value of adenosine test is similar to that of exercise myocardial perfusion imaging and particularly useful in evaluating patients unable to perform exercise test or achieve adequate level of exercise

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

    Energy Technology Data Exchange (ETDEWEB)

    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 mellitus. (K.H.)

  2. 123I-MIBG myocardial scintigraphy in diabetic patients. Relationship with 201Tl uptake and cardiac autonomic function

    International Nuclear Information System (INIS)

    The purpose of this paper is to investigate the influence of diabetic myocardial damage (suspected myocardial damage; SMD) diagnosed by 201Tl-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 123I-MIBG injection. The heart to mediastinum uptake ratio (H/M) and washout ratio of 123I-MIBG (WR) were obtained from both planar images. Similarly, the difference between the 201Tl image and the 123I-MIBG image in the total uptake score (TUS) was taken as the difference in the total uptake score (?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 ?TUS, there was a statistically significant differences between AN [+] subgroups and controls. Similarly, the mean value for ?TUS was much higher in AN [+] subgroups than in AN [-] subgroups with or without SMD in diabetes mellitus. (K.H.)

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

    Energy Technology Data Exchange (ETDEWEB)

    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 mellitus. (K.H.)

  4. Stress-induced myocardial ischemia is associated with early post-stress left ventricular mechanical dyssynchrony as assessed by phase analysis of 201Tl gated SPECT myocardial perfusion imaging

    International Nuclear Information System (INIS)

    In 201Tl SPECT myocardial perfusion imaging (MPI) data are acquired shortly after the stress injection to assess early post-stress left ventricle (LV) function. The purpose of this study was to use 201Tl SPECT MPI to investigate whether stress-induced myocardial ischemia is associated with LV mechanical dyssynchrony. Enrolled in the study were 75 patients who were referred for dipyridamole stress and rest 201Tl gated SPECT MPI. The early post-stress scan was started 5 min after injection, and followed by the rest scan 4 h later. The patients were divided into three groups: ischemia group (N = 25, summed stress score, SSS, ?5, summed rest score, SRS, 201Tl gated SPECT MPI. (orig.)

  5. Comparison study of left ventricular ejection fraction measured by 201Tl gated myocardial imaging and 99mTc-red blood cell gated blood-pool imaging

    International Nuclear Information System (INIS)

    Objective: To explore the correlation of automatic quantification of left ventricular ejection fraction (LVEF) from gated myocardial perfusion SPECT with 201Tl and rest equilibrium gated blood- pool imaging with 99mTc-red blood cell. Methods: Rest gated myocardial perfusion SPECT with 201Tl was performed on 72 cases. AUTOQUANT 4.21 software was used to measure LVEF. Rest equilibrium gated blood-pool imaging was also performed within 24 h. The values of LVEF measured by two methods were calculated and compared. Results: (1)There were strong correlation between the LVEF measured by rest gated myocardial perfusion SPECT and rest equilibrium gated blood-pool imaging(r=0.554, P=0.000). There was no significant difference between the two methods (t=1.194, P>0.05). (2) There was no significant difference between the two methods among different disease groups. (3) The values of LVEF measured by two methods were (64.68 ± 10.77)% and (62.46±8.99)%. The values of LVEF measured by gated myocardial perfusion SPECT was higher 3.55% than rest equilibrium gated blood-pool imaging. Conclusion: There was good correlation between the LVEF measured with gated myocardial perfusion SPECT by AUTOQUANT 4.21 software and gated blood-pool imaging. The LVEF can be accurately evaluated using gated myocardial perfusion SPECT with 201Tl. The value of LVEF measured by gated myocardial perfusion SPECT was higher than rest equilibrium gated blood-pool imaging. (authors)

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

    International Nuclear Information System (INIS)

    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 201Tl redistribution, 2, 14, 3, 3, 4 segments were m anterior, lateral, inferior, apex, interventricular septal segment respectively. 5 all rest 99mTc-MIBI imagines display normal uptake. Conclusion: Simultaneous rest 99mTc-MIBI and stress 201Tl dual-isotopic myocardial perfusion SPECT imaging is an effective auxiliary method in the detection of hypertension and identification of Coronary Artery Disease. (authors)

  7. 201Tl-myocardial SPECT - first experiences with a simultaneous transmission emission acquisition for non-uniform patient-related attenuation correction

    International Nuclear Information System (INIS)

    In this study our first clinical experiences with simultaneous transmission and emission acquisition in 201Tl myocardial SPECT (T/E-SPECT) are discussed. The non-uniform attenuation (AK) was carried out with a triple-head camera (PRISM 3000, Picker Inc.) correction equipped with fanbeam collimators. A line source of 750 MBq 99mTc was used to construct the transmission profile. Prior to investigation patients got 80-120 MBq 201Tl-chloride intraveneously injected. The study comprises the evaluation of 40 patients, derived from the clinical routine. The investigation followed an usual one day protocol. Our results using T/E-SPECT reveal an almost equilibrated activity distribution between anterior and posterior myocardial wall. For this reason it is to be expected that T/E-SPECT provides more reliable information about the posterior myocardial wall, than the usual SPECT technique without attenuation correction. (orig./MG)

  8. Septal Q wave disappearance in V{sub 6} lead and myocardial damage comparison of 12-lead electrocardiography and {sup 201}Tl myocardial SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, Jun [Yokohama City Univ. (Japan). School of Medicine

    1998-01-01

    Septal Q wave disappearance in V{sub 6} has been thought to signify myocardial septal damage. In this study, to verify significance of septal Q wave disappearance in V{sub 6} in cases with anteroseptal myocardial damage, we compared ECG and {sup 201}Tl SPECT findings. The subject were 107 patients (80 males, 27 females, mean age 58.2{+-}10.1 years) who took exercise {sup 201}Tl SPECT because of suspicious of ischemic heart disease. The patients were divided into two groups. One was the patients with septal Q (septal Q (+) group) and the other was the patients without septal Q (septal Q (-) group). The definition of septal Q wave disappearance was that it was smaller than 0.025 mV. The patients with abnormal Q in V{sub 6} were excluded. A SPECT image was divided into 13 segments. Tl uptake scores were classified into 4 levels by visual evaluation at the each segments. Septal Q (-) group had a significantly higher rate of anteroseptal infarction than septal Q (+) group (p=0.01), and showed a significantly higher defect in anteroseptal area (p<0.01). The presence of septal Q wave disappearance has a 51% sensitivity for the diagnosis of anteroseptal myocardial damage and has a 77% specificity. These data suggest that septal Q wave disappearance in V{sub 6} may be one of parameters which assume anteroseptal myocardial damage. (author)

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

    International Nuclear Information System (INIS)

    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)

  10. Quantified myocardial SPECT: Comparative evaluation of 201Tl-chloride and 99mTc-hexakis-(2-methoxy-isobutyl-nitrile) (RP 30) in coronary multivascular disorder

    International Nuclear Information System (INIS)

    Ten patients with multivascular coronary disorder were selected for the comparative SPECT examinations using 99mTc-RP 30 or 201Tl-chloride, under stress and at rest. Good agreement of myocardial uptake of the two substances was observed under stress, but there were deviations from the computed redistribution indexes of both substances. The redistribution index of myocardial regions supplied by stenosed coronary arteries was above 40 p.c. The results obtained so far show an equal, if not superior sensitivity of 99mTc-RP 30 SPECT as compared to the thallium compound, for detection of myocardial stress-induced ischemia. (orig./MG)

  11. Relationship between insufficient redistribution in exercise thallium-201 myocardial single-photon emission computed tomography and reverse redistribution at rest

    International Nuclear Information System (INIS)

    It is widely accepted that perfusion defects in 3 to 4-h delayed images in exercise thallium-201 (201Tl) myocardial scintigraphy underestimate the viability of myocardium in the infarct region. In the present study, to examine the contribution of the condition of myocardium which demonstrates reverse redistribution in resting scintigraphy to the insufficiency of redistribution in the 4-h delayed image in exercise scintigraphy, we performed exercise and resting 201Tl myocardial single-photon emission computed tomography in 58 patients with acute myocardial infarction and a single diseased coronary artery. Twenty eight patients demonstrated reverse redistribution (group RR) and 28 showed a fixed defect (group FD) in resting scintigraphy. Redistribution in the 4-h delayed image in exercise scintigraphy was significantly more insufficient in group RR than in group FD (p<0.01), and the degree of the insufficiency of redistribution in exercise scintigraphy closely correlated with the degree of reverse redistribution in resting scintigraphy (r=0.79, p<0.001). We conclude that in patients with acute myocardial infarction, the condition of myocardium which demonstrates reverse redistribution in resting myocardial scintigraphy is related to the insufficiency of redistribution in the delayed image in exercise scintigraphy. (author)

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

    International Nuclear Information System (INIS)

    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.)

  13. Development and clinical application of an expert system for supporting diagnosis of 201Tl stress myocardial SPECT

    International Nuclear Information System (INIS)

    A consultation expert system which supports our computer aided reporting system was developed. The system was used for the evaluation of the two dimensional polar (bull's eye) display of 201Tl myocardial SPECT. The system consists of patients management (PM) and consultation expert systems (ES). The former is connected to image processors coupled with scinticameras. The bull's eye display of myocardial SPECT is transfered from image processor to the data base of PM. When inference request is made, the feature extraction program extracts information on localization, extent and severity of focal defects comparing count-rates pixel by pixel with the reference obtained from seven normal controls. The inference engine is activated to determine presence of focal defects utilizing diagnostic rules in the knowledge base. The results are sent back to PM and reported with the probability of assurance. Fifty eight patients with old myocardial infarction (OMI), angina pectoris (AP) and other diseases as well as normal controls were included in the study. The decision for presence or absence of focal defects by ES agreed with that by nuclear physicians (NP) in 301 segments among 330 (91%) in stress images. The presence of redistribution in delayed images agreed in 43 segments among 67 (64%). Image interpretation by ES agreed well with that of NP in patients with OMI (19/20) and AP (9/11). Seven were interpreted as normal by both ES and NP. The system is useful, as it provides NP with complementary and supportive information applicable to decision making and reporting. Further clinical experiences can improve knowledge base for better ES function. (author)

  14. Dual-isotope SPET201Tl rest/99Tc-MIBI stress: One-day protocol for pre-operative myocardial imaging?

    International Nuclear Information System (INIS)

    We compared the results of a rest 201Tl/stress 99mTc-MIBI protocol, both by means of separate single isotope and simultaneous dual isotope acquisition, with a standard stress/rest 99mTc-MIBI 2-day protocol in 11 patients with low probability of CAD and 14 patients with chronic CAD. In patients with CAD 406 segments (sgs) were analysed. In the standard protocol 119 sgs were classified as pathological of which 50.4% were fixed and 49.6% reversible defects. With the MIBI-stress/Tl-rest single 33% of 119 pathological sgs were fixed and 67% reversible defects. With the MIBI-stress/Tl-rest dual only 20% were fixed and 80% reversible defects. The reversibility of 59 MIBI-stress/MIBI-rest reversible defects was quantified: MIBI-stress/MIBI-rest 35 ± 16% MIBI-stress/Tl-rest single 50 ± 26% and MIBI-stress/Tl-rest dual 48 ± 22%. The results of 99mTc-MIBI rest and 201Tl rest studies in patients with chronic CAD are not the same. Dual-isotope 1-day 201Tl-rest/99mTc-MIBI-stress SPET data, acquired separately, may give fast and complete information on myocardial perfusion at stress and rest, respectively, and on myocardial viability. (orig.)

  15. When is /sup 201/Tl myocardial scintigraphy indicated. The view of a clinical cardiologist

    Energy Technology Data Exchange (ETDEWEB)

    Klepzig, H. Jr.; Kaltenbach, M.

    1987-12-01

    Myocardial scintigraphy with thallium-201 has met with good acceptance in cardiology and has proven its value. The method implies only low risk and yields diagnostic results that allow verification or disqualification of suspected myocardial ischemia in those cases where there is only reduced accuracy of the exercise electrocardiogram. (TRV).

  16. Differential diagnosis of idiopathic congestive cardiomyopathy and ischemic heart disease by echocardiography and 201Tl-myocardial scintigraphy

    International Nuclear Information System (INIS)

    The usefulness of various non-invasive methods such as electrocardiography, echocardiography and 201Tl myocardial scintigraphy in the differential diagnosis of idiopathic congestive cardiomyopathy (CCM) and ischemic heart disease (IHD) were evaluated. Eighteen cases with CCM and 9 cases with IHD were subjected. For this study patients with IHD showing dilated cavity (LVDd over 66 mm) and diffuse hypokinesis of the left ventricle in the echocardiogram were selected. Cardiothoracic ratio of CCM and IHD were 59.6 +- 6.3% and 58.3 +- 6.3% in average, respectively. In CCM, mean LVDd was 76.0 +- 5.6 mm and mean LVDs was 63.4 +- 7.3 mm. In IHD, mean LVDd was 74.7 +- 8.1 mm and mean LVds was 63.2 +- 4.6 mm. Both cardiothoracic ratios and echocardiographic findings showed no difference between CCM and IHD. Incidence of an abnormal Q wave in ECG was higher in IHD (2.72 leads per a case) than that in CCM (1.33 leads per a case). An abnormal Q wave in aVL was frequently (28%) observed in CCM but none in IHD. However, these ECG findings did not seem to be contributory to the differential diagnosis. Myocardial scintigraphic study revealed that 10 of 18 cases with CCM showed no perfusion defect or sparse uptake and others showed small and isolated defect in the apex or postero-lateral wall of the left ventricle, while 7 of 9 cases with IHD showed large perfusion defect over 15% in the anterior and inferior areas. However, small localized defects less than 14% in the apex were observed in both groups, 5 cases (27.8%) with CCM, and 2 cases (22.2%) with IHD, suggesting limitation of this method for the differential diagnosis. (J.P.N.)

  17. Estimation of perioperative myocardial infarction in patients under aorto-coronary bypass grafts with plasma level of myosin light chain I and 201Tl SPECT

    International Nuclear Information System (INIS)

    After aorto-coronary bypass grafts surgery plasma level of myosin light chain I, determined with monoclonal antibodies to myosin light chain I (LC-I), were studied in 12 patients (pts) without electrocardiographical perioperative myocardial infarction. Rest 201Tl myocardial images were collected before and after surgery. LC-I increased and reached peak levels (15±7 ng/ml) at 91±29 minutes after the aortic declamp. From peak levels LC-I rapidly decreased with fast half-time disappearance (1.4±0.9 hours). In 5 pts of 12 pts LC-I recovered to normal range and MB reached maximum levels (34±23 IU/L) at 18±9 hours after declamp. In 4 pts 201Tl images showed no changes. In 7 pts of 12 pts LC-I decreased to minimum levels (2.7±0.6 ng/ml) at 12±6 hours and then gradually increased to peak levels (5.6±0.9 ng/ml) on day 3±0.9. MB reached maximum level (61±20 IU/L) at 3.2±1 hours. In 201Tl images 3 pts showed suspected new lesion, 2 pts showed no changes and 2 pts showed improvement. No correlation was noted between peak LC-I level and duration of aortic declamp. No significant relation was suspected between early LC-I peak and irreversible myocardial cell injury. From close relationship between aortic declamp and appearance of LC-I peak, it was concluded that LC-I, accumulated during aortic clamp, was washed out by aortic declamp. Relation was suspected between ealy LC-I peak and myocardial injury during myocardial protection. Late LC-I peak may be useful for estimation of perioperative irreversible myocardial injury. (author)

  18. 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

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    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-infarction and remote ischaemia was 70% (kappa = 0.37) and 80% (kappa = 0.59) respectively. It is concluded that dobutamine stress echocardiography and {sup 201}Tl SPET have comparable accuracy for the diagnosis of infarct related and remote CAD in patients with previous myocardial infarction. The agreement between the methods is higher for the diagnosis of remote CAD than for that of peri-infarction ischaemia. (orig.) With 3 figs., 32 refs.

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

    International Nuclear Information System (INIS)

    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)

  20. Clinical studies on thallium-201 myocardial single-photon emission computed tomography in patients with ischemic heart disease

    International Nuclear Information System (INIS)

    In order to evaluate briefly the relative 3-dimensional distribution of 201Tl in the myocardium, a 2-dimensional polar map was developed from short axis tomograms of single-photon emission computed tomography (SPECT) using circumferential profile analysis. The data collected from 180 deg rotational scan around a body were used in clinical study to acquire the projection data in a short time, although, with a heart phantom study, there was more uniformity with the 360 deg collection than with 180 deg collection. So, the polar map of relative distribution and % washout rate (% WR) were created from 180 deg data collection. To detect ischemic area, the lower limit (M-SD) of the profile curve in 10 normal subjects was processed and compared with that of patients. Then, abnormal 201Tl distribution and % WR were identified comparing each patient's profile with the corresponding normal lower limits. In 24 patients with myocardial infarction, defect score (DS), estimated as infarcted size from the relative polar map, was compared with the size of abnormal wall motion in left ventriculography. There was a good correlation (r = 0.834) between them. Also, there were close correlations between DS and regional contraction (r = -0.869), and between DS and left ventricular ejection fraction (r = -0.775) respectively. In 24 patients with non-MI angina pectoris, the diagnostic sensitivity of exercise induced ischemia was 65 % and accuracy was 76 % by relative distribution map. However, the sensitivity of % WR map was superior (84 %) to that of relative map, especially in the patients with mild ischemia and multi-vessel disease. In conclusion, this comprehensive polar map method represented well a 3-dimensional myocardial distribution of 201Tl. The clinical usefulness in determination of infarct size and in diagnosis of myocardial ischemia were evaluated. (author)

  1. Effect of long-term cholesterol-lowering treatment with HMG-CoA reductase inhibitor (Simvastatin) of myocardial perfusion evaluated by thallium-201 single photon emission computed tomography

    International Nuclear Information System (INIS)

    Fifteen patients with either angina pectoris or old myocardial infarction, who had positive 201Tl single photon emission computed tomography (SPECT) imaging and coronary sclerosis of more than 50%, were treated with an HMG-CoA reductase inhibitor (simvastatin) for more than 1 year. They were compared with an untreated control group (n=25). Total cholesterol decreased 22% and high-density lipoprotein (HDL) increased 9% with simvastatin; both changes were significantly different from those in controls. Long-term simvastatin induced improvement of myocardial perfusion on 201Tl SPECT images both during exercise and at rest, which was also significantly different from controls. In addition, the improvement of myocardial perfusion on 201Tl SPECT images was clearly related to the improvements in cholesterol values, especially nonHDL cholesterol. Thus, the greater the decrease in nonHDL cholesterol, the greater the improvement in myocardial perfusion at rest or during exercise with long-term treatment using an HMG-CoA reductase inhibitor. These findings indicate that the improvements in cholesterol values caused by HMG-CoA reductase inhibitor therapy are related to improvements of myocardial perfusion seen on 201Tl SPECT images. (author)

  2. Clinical investigation of large perfusion defect cases with {sup 201}Tl exercise myocardial scintigraphy

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    Morota, Motoi; Kobayashi, Yasuhiko [Tokyo Medical Coll. (Japan)

    1999-02-01

    We investigated retrospectively the clinical significance of large perfusion defect on {sup 201}Thallium myocardial scintigraphy from the records of 833 patients during the past 3 years from 1991 to 1994. The patients were divided into 3 groups according to the extent of perfusion defect; cases with normal perfusion (n=561), with small perfusion defect (n=211) and with large perfusion defect (n=61). We found that the proportions of cases with large perfusion defect was significantly larger than that of cases with small perfusion defect in myocardial disease (MD; hypertrophic cardiomyopathy, dilated cardiomyopathy, and post myocarditis combined) (P<0.001). Analyzing patients with ischemic heart disease (IHD; angina pectoris and myocardial infarction) according to the severity of coronary artery lesion, the proportion of cases with large perfusion defect was significantly larger than that of cases with small perfusion defect in 3 vessel disease (P<0.001). Incidence of diabetes mellitus was significantly higher in patients with IHD than in those with MD in large perfusion defect group (P<0.01). As for symptoms in large perfusion defect group, the incidences of chest pain, chest oppression, and chest discomfort were significantly higher in patients with IHD than in those with MD (P<0.001), whereas the incidences of palpitation and shortness of breath were significantly higher in patients with MD (P<0.001). These results suggest that IHD with multiple artery lesions and MD underlie large perfusion defect on {sup 201}Thallium myocardial scintigraphy and that complication of diabetes mellitus and clinical symptoms may be useful in differentiating IHD from MD. (author)

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

    International Nuclear Information System (INIS)

    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 (?ES and ?SS) 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 ?ES and ?SS. 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 ?ES and ?SS. 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.)

  4. Significance of delayed redistribution on exercise 201Tl myocardial SPECT in patients with ischemic heart disease

    International Nuclear Information System (INIS)

    The purpose of this study was to evaluate the significance of delayed redistribution on 24-hr SPECT images. Exercise thallium-201 myocardial SPECT was performed using a sitting ergometer in a total of 39 patients with myocardial infarction (n=27) or angina pectoris (n=12). SPECT images were acquired immediately, 3 hours and 24 hours after exercise. Twenty-four hour images were evaluable in all patients. Delayed redistribution was seen in 14 patients (36%). It was seen in 8 of 27 infarcted areas (30%) and in 10 of 36 non-infarcted ischemic areas (28%). Infarcted areas showing delayed redistribution was associated with significantly decreased %Tl uptake on images immediately after exercise, as compared with infarcted areas without delayed redistribution. In this group, coronary stenosis was also significantly severe and was associated with definitive collateral circulation. Delayed redistribution is a useful means of evaluating viability of the myocardium accurately without the need for increasing exposure doses in patients with myocardial infarction especially when %Tl uptake is decreased immediately after exercise and coronary arteries are severely stenosed associated with collateral circulation. (N.K.)

  5. The evaluation of left ventricular eccentric hypertrophy by 201Tl-myocardial scintigraphy

    International Nuclear Information System (INIS)

    In order to elucidate the mechanism of left ventricular eccentric hypertrophy in conditions of volume overload, Tl-201 myocardial scintigraphy was performed in patients with aortic valve regurgitation and mitral valve regurgitation. There was a good relationship between the severity of Tl-defects, as determined by Tl-201 myocardial scintigraphy, and the changes in the T wave on the ECG on the one hand and the NYHA functional classification of heart diseases. In 17 of 18 patients where LVDd increased with increasing severity of Tl-defects and the defects were moderate to severe, LVDd was 65 mm or larger. There was a significant negative correlation between the washout rate for the whole circumference of the left ventricle, as determined by exercise Tl-201 SPECT, and LVDd (r=-0.603, p<0.01). The phenomenon of redistribution as determined by exercise Tl-201 myocardial scintigraphy was observed relatively early. Our results suggest that mechanical volume overload and ischemic changes are involved in left ventricular wall damage in left ventricular eccentric hypertrophy. For patients with moderate to severe Tl-defects valve replacement is indicated, no matter whether they may have heart failure or arrhythmia. (author)

  6. Results of RNV studies and 201Tl myocardial scintigraphy in patients with progressive systemic scleroderma (PSS)

    International Nuclear Information System (INIS)

    Prognosis of progressive systemic scleroderma (PSS) depends directly on the extent of visceral organ involvement, and in particular, on the cardiac, renal and pulmonary appearance. Therapeutic approaches therefore require periodic followup with non-invasive methods to evaluate the actual course of disease and the success of therapy. Tl-201 scintigraphy showed pathologic heart abnormalities in 47% and RNV in 23% of the PSS patients. Our results and published data reveal the sensitivity of both myocardial scans and RNV in the evaluation of patients with PSS. Other current methods for the diagnosis of heart diseases, however, such as echocardiography should also be performed. In patients with PSS coronary angiography, however, usually shows normal coronary vessels. (orig.)

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

    International Nuclear Information System (INIS)

    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

  8. 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

    International Nuclear Information System (INIS)

    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 bypass graft (CABG) surgery. A total of 39 patients with CAD was enrolled (34 men and 5 women), aged between 36 and 72 years (mean 58 ± 8 standard in years) who underwent both pre- and 3 months post-CABG myocardial SPECT. We analyzed 17 myocardial segments per patient. Perfusion status and wall motion were semi-quantitatively evaluated using a 4-point grading system. Viable myocardium was defined as dysfunctional myocardium which showed wall motion improvement after CABG. The left ventricular ejection fraction (LVEF) significantly increased from 37.8 ± 9.0% to 45.5 ± 12.3% (p 201Tl rest perfusion status (p = 0.024) were significant predictors of wall motion improvement. However, in multiple logistic regression analysis, stress/rest reversibility alone was a significant predictor for post-CABG wall motion improvement (p < 0.001). Stress/rest reversibility (impaired CFR) during dual-isotope gated myocardial perfusion SPECT was the single most important predictor of wall motion improvement after CABG.

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

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    Ito, Kazuki; Tanabe, Takuji; Yuba, Tatsuya; Doue, Tomoki; Adachi, Yoshihiko; Katoh, Shuuji [Asahi Univ., Gifu (Japan). Murakami Memorial Hospital; Sugihara, Hiroki; Azuma, Akihiro; Nakagawa, Masao

    2001-07-01

    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 <1.5 cm{sup 2}) included 6 patients, mildly stenostic group (1.5 cm{sup 2}{<=} valve area <2.5 cm{sup 2}) included 9. A 111 MBq of {sup 123}I-BMIPP was intravenously injected at rest, SPECT images were obtained at 15 min and 3 hours after injection. A 111 MBq of {sup 201}Tl was intravenously injected at rest, and SPECT images were obtained at 15 min after injection. Washout rate (WR) of {sup 123}I-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. {sup 123}I-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 (p<0.05). NE values were 480{+-}69 and 743{+-}295 in the mildly and severely stenotic groups, respectively. NE value was increased in severely stenotic group (p<0.05). Twelve patients showed normal uptake on both {sup 201}Tl and {sup 123}I-BMIPP myocardial SPECT. Three patients showed slightly reduced uptake on both {sup 201}Tl and {sup 123}I-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 heart failure group and severely stenotic group without apparent myocardial damage. Myocardial metabolism in the left ventricle might be influenced by right heart failure through, for example, NE and neurohormonal factors. (author)

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

    International Nuclear Information System (INIS)

    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-?-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)

  11. Diagnostic accuracy of supine and prone thallium-201 stress myocardial perfusion single-photon emission computed tomography to detect coronary artery disease in inferior wall of left ventricle

    International Nuclear Information System (INIS)

    Prone thallium-201 (201Tl) myocardial perfusion single-photon emission computed tomography (SPECT) reduces false-positive rates when evaluating inferior wall abnormalities by minimizing diaphragmatic attenuation. The present study investigates the diagnostic validity of prone 201Tl stress myocardial perfusion SPECT for detecting coronary artery disease in the inferior wall of the left ventricle in Japanese patients. Of the 104 consecutive patients who underwent 201Tl stress myocardial perfusion SPECT to diagnose coronary artery disease, we evaluated 46 who underwent image acquisition in both the supine and prone positions, and coronary angiography within 3 months thereafter. Images were acquired in the routine supine position immediately following 201Tl (111 MBq) injection and 4 h following early acquisition. Images were acquired in the prone position only during the early phase following supine acquisition. We evaluated the SPECT images of the inferior half segments of the left ventricle using a five-point defect scoring system. According to the coronary angiographic findings, we investigated the diagnostic accuracy of stress-rest supine, stress supine, stress prone, and combined supine-prone images. Reduced uptake in the stress supine image of the combined images was considered as attenuation when uptake was normal in the prone image. The sensitivity of the stress-rest supine, stress supine, stress prone, and stress-combined supine-prone images was 77%, 86%, 55%, and 55%, and the specificity was 71%, 54%, 79%, and 83%, respectively. Diagnostic accuracy was the highest in stress-rest supine images. Prone images tended to improve the specificity of detecting coronary artery disease in the inferior wall, but not diagnostic accuracy compared with stress-rest supine images because of decreased sensitivity. (author)

  12. Aspects of recovery from regional wall motion abnormalities after exercise in patients with ischemic heart disease using 201Tl myocardial dynamic SPECT

    International Nuclear Information System (INIS)

    Using 201Tl myocardial dynamic SPECT (dynamic SPECT), we studied various aspects of the recovery from exercise-induced ischemia, particularly the mechanism of delayed recovery from wall motion abnormality. The subjects were 23 patients with ischemic heart disease who underwent coronary angiography, exercise stress two-dimensional echocardiography (ESE), and dynamic SPECT. Using a 3-head SPECT system, dynamic SPECT was performed for 33 min consecutively from 5 min after the intravenous injection of 201TlCl (Tl). The regional early washout rate (early WR) was determined at 20, 29, and 38 min after Tl injection, and the delayed washout rate (delayed WR) was determined at 240 min. From the duration of regional wall motion abnormalities on ESE, the patients were divided into Group A (wall motion abnormalities persisting for ?20 min, n=8) and Group B (<20 min, n=15). At each point of assessment, early WR was significantly lower in Group A than in the control group (5 healthy subjects) and Group B (p<0.01). In addition, the early WR at 20 min was negative in all Group A patients. The present study suggests that a persistent relative and reduction in myocardial blood flow is one factor responsible for prolonged abnormal regional wall motion. (author)

  13. Exercise and rest myocardial scintigraphy with 201TlCl/99mTc-MIBI dual energy acquisition using triple-energy window scatter correction

    International Nuclear Information System (INIS)

    We carried out dual 201Tl/99mTc-MIBI imaging to reduce the time required for exercise myocardial scintigraphy. We investigated 4 different protocols. In protocol (A), Tl was injected at rest followed by the injection of MIBI at peak exercise. Dual SPECT images were obtained by 201Tl/99mTc simultaneous acquisition. Protocol (B) means reverse either, in which MIBI was injected at rest followed by the administration of Tl at peak exercise. In protocol (C), exercise was performed first with MIBI-injection, and then Tl was injected at rest one hour later. Simultaneous acquisition was also performed. In protocol (D), after the rest Tl-imaging, MIBI was injected at peak exercise, and then the MIBI-imaging was done. In protocol (A), (B) and (C), simultaneous acquisition was performed using TEW (Triple-Energy Window) scatter correction. Thanks to using dual isotopes, all procedures could be completed within 1-2 hours, which was much shorter than the conventional myocardial perfusion imaging. Scatter correction was useful for accurate diagnoses, when the simultaneous imaging is performed. (author)

  14. Evaluation of mandibular invasion by head and neck cancers using 99mTc-methylene diphosphonate or 99mTc-hydroxymethylene diphosphonate and 201Tl chloride dual isotope single photon emission computed tomography

    International Nuclear Information System (INIS)

    Whether a patient with head and neck cancer has mandibular invasion or not is important in determining the method of resection surgery. But, no modality is adequately reliable when used alone in the evaluation of mandibular invasion. Therefore, to more accurately diagnose mandibular invasion in head and neck cancer, we used a new modality, namely, 99mTc methylene diphosphonate (MDP) or 99mTc hydroxymethylene diphosphonate (HMDP) and 201Tl chloride dual isotope single photon emission computed tomography (Tc/Tl SPECT). The aim of this study is to disclose the usefulness of Tc/Tl SPECT in the assessment of mandibular invasion by head and neck cancers. 99mTc-MDP or -HMDP SPECT (Tc SPECT)s and 201Tl chloride SPECT (Tl SPECT)s were performed in 34 patients with suspected mandibular involvement of head and neck cancer. Thirty of 34 cases underwent both Tc/Tl SPECT and CT examination. Tc/Tl SPECT fusion images were obtained using the Automatic Registration Tool (ART, TOSHIBA, Japan) system. In the diagnosis of mandibular invasion on Tc/Tl SPECT fusion images, a problem was that the range of Tc and Tl uptake was changed by the condition of display used in the reconstruction and expression of the images. Then, prior to clinical evaluation, to reveal the most appropriate upper window level for display, a phantom study was performed. In a clinical study, the upper window level was set at 40 or 50%, which were verified to be the proper values in the preliminary study. The diagnostic accuracy obtained using Tc SPECT, Tc/Tl SPECT and CT was compared with the histopathological findings. Tc/Tl SPECT at 40 and 50% upper window level had higher specificity, accuracy, and positive predictive value (73.3%, 85.3%, 81.8%) than Tc SPECT alone (21.4%, 67.6%, 64.5%) and higher sensitivity and negative predictive value (94.7%, 91.7%) than CT (70.6%, 72.2%) for detecting mandibular invasion. Tc/Tl SPECT was a useful diagnostic procedure for the assessment of mandibular invasion by head and neck cancers. (author)

  15. 201Tl labelled myocardium tomoscanning

    International Nuclear Information System (INIS)

    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

  16. Precision of electrocardiographic diagnosis of myocardial infarction in the ventricular septal area. Comparison with 201-TlCl scintigraphy and coronary angiography

    International Nuclear Information System (INIS)

    The purpose of this study was to clarify the diagnostic accuracy of 3 electrocardiographic (ECG) indexes including Q waves in V1[QV1(+)], Q waves in V1 and V2 [QV1V2(+)], and absence of septal q waves in V6 [qV6(-)] for prediction of myocardial infarction (MI) in the interventricular septal area (IVS) using 201-TlCl myocardial scintigraphy. In addition, we also evaluated the relationship between these ECG indexes and the site of the culprit lesions in the left anterior descending artery (LAD). This study consisted of 115 patients (100 males; mean age, 60 years) with anteroseptal MI who underwent 201-TlCl myocardial scintigraphy in our hospital between January 1994 and December 1997. One hundred six of them also underwent coronary angiography (CAG). On extent maps obtained from SPECT images of 201-TlCl scintigraphy, the area of MI occupying the IVS area, using the proportion of the defect area in the IVS, was expressed as % defect area (%DA). Three patterns of %DA were defined as follows. A: 50%?%DA?100%; B: 70%?%DA?100%; and C: 90%?%DA?100%. On scintigraphic evaluations, %DA in patients with each of the 3 ECG indexes was significantly larger than %DA in patients without them (p=0.0002, p=0.0008, and p=0.0008, respectively). QV1(+) and qV6(-) showed good sensitivities only for pattern C (79% and 75%, respectively), but all ECG indexes showed low sensitivities for patterns A and B. Regarding specificity, QV1V2(+) showed the best values (76% for pattern A, 68% for pattern B, and 68% for pattern C) among the 3 ECG indexes. For prediction of the culprit lesions located proximal to the origin of the first septal branch, qV6(-) showed a relatively good sensitivity (67%) and specificity (67%). For prediction of MI in the IVS area, QV1(+) and qV6(-) showed good sensitivities when the MI was sufficiently large in size. QV1V2(+) showed relatively good specificities irrespective of the MI size. qV6(-) was the best predictive index for the culprit lesions located in the proximal site of the LAD. (author)

  17. Stress-induced myocardial ischemia is associated with early post-stress left ventricular mechanical dyssynchrony as assessed by phase analysis of {sup 201}Tl gated SPECT myocardial perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chien-Cheng; Shen, Thau-Yun [Show Chwan Memorial Hospital, Department of Cardiology, Changhua (China); Chang, Ming-Che [Changhua Christian Hospital, Department of Nuclear Medicine, Changhua (China); Hung, Guang-Uei [Chang Bing Show Chwan Memorial Hospital, Department of Nuclear Medicine, Changhua (China); China Medical University, Department of Biomedical Imaging and Radiological Science, Taichung (China); Chen, Wan-Chen [Chang Bing Show Chwan Memorial Hospital, Department of Nuclear Medicine, Changhua (China); Kao, Chia-Hung [China Medical University, Department of Biomedical Imaging and Radiological Science, Taichung (China); Chen, Ji [Emory University School of Medicine, Department of Radiology and Imaging Sciences, Atlanta, GA (United States)

    2012-12-15

    In {sup 201}Tl SPECT myocardial perfusion imaging (MPI) data are acquired shortly after the stress injection to assess early post-stress left ventricle (LV) function. The purpose of this study was to use {sup 201}Tl SPECT MPI to investigate whether stress-induced myocardial ischemia is associated with LV mechanical dyssynchrony. Enrolled in the study were 75 patients who were referred for dipyridamole stress and rest {sup 201}Tl gated SPECT MPI. The early post-stress scan was started 5 min after injection, and followed by the rest scan 4 h later. The patients were divided into three groups: ischemia group (N = 25, summed stress score, SSS, {>=}5, summed rest score, SRS, <5), infarct group (N = 16, SSS {>=}5, SRS {>=}5) and normal group (N = 34, SSS <5, SRS <5). LV dyssynchrony parameters were calculated by phase analysis, and compared between the stress and rest images. In the ischemia group, LV dyssynchrony was significantly larger during stress than during rest. On the contrary, LV dyssynchrony during stress was significantly smaller than during rest in the normal and infarct groups. LV dyssynchrony during rest was significantly larger in the infarct group than in the normal and ischemia groups. There were no significant differences in LV dyssynchrony during rest between the normal and ischemia groups. Stress-induced myocardial ischemia caused dyssynchronous contraction in the ischemic region, leading to a deterioration in LV synchrony. Normal myocardium had more synchronous contraction during stress. The different dyssynchrony pattern between ischemic and normal myocardium early post-stress may aid the diagnosis of coronary artery disease using {sup 201}Tl gated SPECT MPI. (orig.)

  18. Clinical significance of diffuse slow washout pattern (DSWO) on the exercise stress 201Tl SPECT myocardial imaging: Correlative study with influencing factors

    International Nuclear Information System (INIS)

    DSWO shown on the Bull's eye images was found in 98 of 1234 patients suspected of having coronary artery disease and examined with 201Tl myocardial SPECT imaging. 48 of these 98 patients underwent coronary arteriography. Comparison studies were performed between Bull's eye SPECT image, coronary arteriography and laboratory data. DSWO was found in 11 cases with single vessel disease (1VD), 18 cases with double vessel disease (2VD) and 21 cases with triple vessel disease (3VD). Three of 58 cases with stenosis of a cardiomyopathy. In the CAD group, DSWO appeared frequently accompanying hypertension, hyperlipemia and diabetes mellitus. These complications tended to increase in patients with 1VD and the stenosis less than 75%

  19. Acute and reperfused myocardial infarction: relations between 'reverse redistribution' of 201Tl at rest, micro-perfusion and myocardial viability

    International Nuclear Information System (INIS)

    The mechanism of 'reverse redistribution' (RR) of thallium after myocardial infarction remains obscure. In fact, the fixation of thallium depends on the coronary flow rate, microcirculation and cellular viability. We have studied the RR in 18 patients with normal coronary flow rate after reperfusion of artery of acute phase infarction but with a large range of micro-circulation alteration (evaluated by intracoronary contrast echography (ICCE)) and necrosis size. A thallium rest-redistribution achieved at the eighth day (8D) and 42D was compared with a perfusion score established by ICCE and analyses of the echographic regional kinetics achieved at 0D, 8D and 42D. At 8D a RR was observed in 16/18 patients with a 15 minute average defect of 25 ± 15% of myocardium extended up to 34 ± 13% at 4 hours. At 42D only 6/18 patients retained a RR while the average changes in the size of defect were not significant. The defect measured at 8D on the 15 min. image alone showed to be significantly correlated with the perfusion score while the patients with bad micro-perfusion had defects significantly larger than the others. On the other side the size of the same defect at 15 min. showed to be correlated to that of redistribution at 42D as well as the number of the akinetic segments at 42D. In conclusion, a large a RR is present at 8D after acute reperfusion of a myocardial infarction and tends to vanish at 42D. The 15 minute images reflect essentially the micro-perfusion. The last one being a necessary condition of myocardial salvation, the size of the 15 minute defect is also correlated to the viability indices evaluated at 42D

  20. 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

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Woo [Dept. of Nuclear Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam (Korea, Republic of); So, Young [Dept. of Nuclear Medicine, Konkuk University School of Medicine, Seoul (Korea, Republic of); Kim, Ki Bong; Lee, Dong Soo [Seoul National University Hospital, Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2014-04-15

    The aim of this study was to investigate the most robust predictor of myocardial viability among stress/rest reversibility (coronary flow reserve [CFR] impairment), {sup 201}Tl perfusion status at rest, {sup 201}Tl 24 hours redistribution and systolic wall thickening of {sup 99m}Tc-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 bypass graft (CABG) surgery. A total of 39 patients with CAD was enrolled (34 men and 5 women), aged between 36 and 72 years (mean 58 ± 8 standard in years) who underwent both pre- and 3 months post-CABG myocardial SPECT. We analyzed 17 myocardial segments per patient. Perfusion status and wall motion were semi-quantitatively evaluated using a 4-point grading system. Viable myocardium was defined as dysfunctional myocardium which showed wall motion improvement after CABG. The left ventricular ejection fraction (LVEF) significantly increased from 37.8 ± 9.0% to 45.5 ± 12.3% (p < 0.001) in 22 patients who had a pre-CABG LVEF lower than 50%. Among 590 myocardial segments in the re-vascularized area, 115 showed abnormal wall motion before CABG and 73.9% (85 of 115) had wall motion improvement after CABG. In the univariate analysis (n = 115 segments), stress/rest reversibility (p < 0.001) and {sup 201}Tl rest perfusion status (p = 0.024) were significant predictors of wall motion improvement. However, in multiple logistic regression analysis, stress/rest reversibility alone was a significant predictor for post-CABG wall motion improvement (p < 0.001). Stress/rest reversibility (impaired CFR) during dual-isotope gated myocardial perfusion SPECT was the single most important predictor of wall motion improvement after CABG.

  1. Quantitative rotational tomography with 201Tl and 99mTc 2-methoxy-isobutyl-isonitrile. A direct comparison in normal individuals and patients with coronary artery disease

    International Nuclear Information System (INIS)

    We tested the hypothesis that 99mTc 2-methoxy-isobutyl-isonitrile (99mTc MIBI), a new radiopharmaceutical for myocardial perfusion imaging, provides accurate noninvasive detection of coronary artery disease (CAD). Imaging in patients after exercise and at rest with 99mTc MIBI was compared with imaging after exercise and redistribution with 201Tl in 12 normal subjects and 38 patients with angiographic documentation of CAD (greater than or equal to 50% diameter stenosis). We used single-photon emission computed tomography (SPECT) and computer quantitation of regional tracer distribution. The quality of reconstructed images with 99mTc MIBI judged visually was superior to that of 201Tl in 88% of all studies performed and was comparable in the others. With the limits of normal as 2.5 SD below the mean of gender-matched normal volunteers, 201Tl SPECT identified 32 and 99mTc MIBI identified 36 patients with CAD (p = 0.2). 201Tl SPECT identified 45 of 75 (60%) and 99mTc MIBI identified 59 of 75 (79%) stenosed coronary arteries (p less than 0.05). The quantitative severity of perfusion defects was similar for the two tracers. 201Tl SPECT identified 104 reversibly ischemic myocardial segments compared with 134 with 99mTc MIBI (p less than 0.05). Thus, SPECT myocardial perfusion imaging with 99mTc MIBI and computer quantitation provides an accurate method for the noninvasive detection of significant coronary artery disease. Furthermore, image quality is generally superior to 201Tl, and reversibly ischemic myocardial segments may be better identified with 99mTc MIBI

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

    International Nuclear Information System (INIS)

    The effects of ischemia-reperfusion-induced myocardial damage on the single pass extraction and retention of 64Cu-pyruvaldehyde-di-(N4-methylthiosemicarbazone) (64Cu-PTSM) in perfused rat hearts were compared to these effects on that of 201Tl and 14C-iodoantipyrine. 201Tl and 14C-iodoantipyrine did not show significant changes, but in the case of 64Cu-PTSM, the single pass extraction and retention was reduced with reperfusion. These findings indicate that ischemia-reperfusion-induced myocardial damage decrease the generator-produced 62Cu-labeled 62Cu-PTSM extraction and retention, and that 62Cu-PTSM might have potential not only as a blood flow tracer but also as a functional tracer. (author)

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

    International Nuclear Information System (INIS)

    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)

  4. 201Tl-myocardial scintigraphy: Current status in coronary artery disease, results of sensitivity/specificity in 3092 patients and clinical recommendations

    International Nuclear Information System (INIS)

    This review is concerned with qualitative and quantitative sectorial 201Tl-redistribution analysis of exercise myocardial scintigraphy (EMS). In 3092 cases the sensitivity (specificity) was on average 83(90)%, the average CAD prevalence scintigraphy (EMS). In 3092 cases the sensitivity (specificity) was in average 83(90)%, the average CAD prevalence being 71%. Sensitivity (Se) for EMS (ExECG) increased from 73(43)% in single vessel disease through 83(69)% in double vessel to 90(77)% in triple disease (n = 879); average Se was 77% for LAD-, 79% for RCA- and 65% for LCX-stenosis. Se for detection of the real extension of CAD conversely decreased from 59% in SVD through 41% in DVD down to 33% in TVD. Clinical recommendations for EMS and rest scans are outlined in CAD (atypical angina, follow-up after bypass-surgery, percutaneous transluminal angioplasty), in non-coronary artery diseae (non-ischemic cardiomyopathies, right ventricular hypertrophy) and in pediatric cardiology. (orig.)

  5. 201Tl heart studies

    International Nuclear Information System (INIS)

    At the annual meeting of the Society of Nuclear Medicine there was a preponderance of papers dealing with the heart. The most impressive papers detailed the use of monovalent cation 201Tl in the evaluation of coronary artery disease. Thallium-201 behaves like potassium in that it enters heart muscle quickly and persists in that organ for several hours. It is unlike most radioactive potassium analogues used for heart studies in that: (1) its gamma energy peaks (69 keV and 80 keV) are more easily collimated with resultant image improvement, (2) its physical half life of 72 hours is sufficiently short to attain high counting rates without too much radiation and is sufficiently long so that storage is not prohibitive, (3) its short half life and lack of Beta radiation results in lower radiation to the patient, and (4) its uptake in heart is greater and uptake in liver and stomach less than other potassium analogues

  6. Computer-aided semi-quantitative myocardial scintiscanning using 201-Tl in routine examinations to diagnose coronary heart disease

    International Nuclear Information System (INIS)

    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)

  7. Relation between myocardial damage and disease activity in patients with systemic lupus erythematosus by exercise {sup 201}Tl scintigraphy

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    Kuzumoto, Masayuki [Nara Medical Univ. (Japan)

    1997-08-01

    Myocardial damage in patients with systemic lupus erythematosus (SLE) was evaluated using exercise thallium-201 myocardial scintigraphy, and the relationship between myocardial damage and disease activity of SLE was examined. Twenty-seven patients (26 women and 1 man, mean age 43 years), in whom extramural coronary artery lesions were excluded by coronary angiogram or presumed to be excluded by exercise electrocardiogram, were enrolled in this study. The mean duration of disease and the mean duration of corticosteroid therapy in these patients were 94 and 77 months, respectively. Exercise thallium-201 scintigraphy was performed twice (mean interval, 30 months) to evaluate the progression of myocardial damage. Myocardial ischemia as an index of myocardial damage was evaluated by visual analysis and ischemic score (IS). The changes in myocardial ischemia were categorized into 3 groups: improved, unchanged or worsened. The disease activity of SLE was determined by the SLE Disease Activity Index (SLEDAI), and the changes in this index were classified into the same three categories, as evaluated every six months between the two scintigraphic examinations. Disease activity was significantly correlated with myocardial ischemia (p<0.05), and with myocardial ischemia as diagnosed by {Delta}IS (difference in ischemic score between the first and second thallium-201 scintigrams: p<0.005). But neither the duration of disease nor the duration of corticosteroid therapy was correlated with IS at the first scintigraphy. These results indicate that control of SLE disease activity may be critical in the treatment of myocardial damage resulting from vascular lesions, especially intramyocardial small-artery disease, in patients with SLE. (author)

  8. Clinical evaluation of 123I-BMIPP myocardial SPECT in patients with hypertensive heart disease and hypertrophic cardiomyopathy. Comparison with the findings of 201Tl SPECT and Gd enhanced magnetic resonance imaging

    International Nuclear Information System (INIS)

    123I-BMIPP SPECT (123I-BMIPP), 201Tl SPECT (201Tl), and Gd-DTPA enhanced magnetic resonance myocardial imaging (MR) were performed in patient groups with hypertensive heart disease (HHD), apical hypertrophic cardiomyopathy (APH), and hypertrophic cardiomyopathy without APH (HCM). SPECT was divided into 20 segments and each segment was scored as one of 4 grades (0=normal; 1=mildly decreased; 2=severely decreased; and 3=defect) according to the RI uptake. Gd enhancement in MR was interpreted visually. A decreased in the uptake of 123I-BMIPP showed in 54 of 141 hypertrophic (>13 mm, measured by ultrasonic cardiography) segments in HHD, in 32 of 66 in APH and in 103 of 207 in HCM respectively. Whereas 201Tl SPECT showed decreased uptake in 18 of 141 hypertrophic segments, in 18 of 66 in APH, and in 27 of 207 in HCM, respectively 123I-BMIPP showed a higher incidence of these scintigraphic abnormalities than did 201Tl in the hypertrophic segments. And also in the hypertrophic segments, decreased in the uptake of 123I-BMIPP occurred more frequently in HCM than in HHD. In HCM, decreased 123I-BMIPP uptake appeared more frequently in segments 1, 2, 9, and 10 (antero-septal junction) than in other segments, but in APH, such decreases occurred more often in segments 17, 18, 19, and 20 (apex). Enhanced signal intensity with Gd-DTPA appeared in more segments in the HCM group than in the APH or HHD groups. We concluded that HCM had the most extensive and severe structural changes-including metabolic and ischemic changes-among three groups, and that the combination of these three examinations was useful for evaluating the characteristics of hypertrophic myocardium. (author)

  9. Incremental value of 24-hour delayed imaging in 201Tl stress myocardial perfusion studies (MPS) with an 'early rest reinjection' protocol

    International Nuclear Information System (INIS)

    Full text: One hundred patients (pts) undergoing stress MPS had 24 h imaging for fixed defects at 4 h delayed imaging. 53 had prior myocardial infarction (MI) and 71 were males. Stress employed isotonic exercise with dipyridamole (0.56 mg kg-1) infusion in 57 pts, exercise alone in 33 and dipyridamole alone in 10. All pts with stress defects had rest-reinjection of 40 MBq of 201Tl after stress imaging had been completed, and most had sublingual nitrate therapy 10 min before reinjection. MPS from the 100 pts (15% of total) were read without clinical data, using a 20 segment scoring system. 51 pts showed -2 segments improvement between 4 and 24 h scores, but 22 pts had shown reversibility between stress and 4 h imaging and the further change did not alter interpretation. The other 29 pts (group A) showed clinically important change in 24 h scores, leaving 71 pts without clinical change (group B). Segmental improvement between 4 and 24 h in group A was 4.62 ± 2.18 and 1.18 ± 1.48 in group B (P = 0.02). Group A stress defect scores were not greater (10.90 ± 3.60) or more severe (3.72 ± 3.06) than in group B (8.92 ± 4.34 and 2.79 ± 3.11); 18 group A pts had MI compared with 38 group B pts. No significant correlation was found between improved 4-24 h scores and parameters of stress-LV dysfunction. There is benefit from 24 h, 201TI MPS in patients with persisting 4 h defects, despite early rest-reinjection and acute nitrate therapy

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

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

  12. Clinical assessment of effects of nitroglycerin ointment in patients with angina pectoris by quantitative stress 201Tl myocardial scintigraphy

    International Nuclear Information System (INIS)

    The effects of nitroglycerin ointment (NGO) on angina pectoris (AP), especially the increase in regional coronary blood flow were clinically examined using stress Tl-201 myocardial scintigraphy in 26 patients with AP. Scintigraphic findings included: (1) an improvement of perfusion defect due to an increased Tl-201 uptake in ischemic areas, (2) an improvement of defect in spite of unchanged uptake in ischemic areas, and (3) no improvement of defect. From these findings, two mechanisms of NGO action are considered in the presence or absence of the coronary artery response (spasm or an increased coronary artery tonus) which plays an important role in the occurrence of AP. That is, there seems to be an increased regional coronary blood flow resulting from the dilatation of the coronary artery, or the lowered pre- or post-cardiac load. (Namekawa, K.)

  13. Fractioning and control of 201 Tl chloride for clinical use

    International Nuclear Information System (INIS)

    Heart scintigraphy with 201 Tl chloride is largely used to study myocardial perfusion in several diseases as a fundamental tool in clinical or surgical approaches. Due to the high price of 201 Tl chloride, the Centro de Medicina Nuclear decided to import such a radionuclide in bulk form in order to reduce the price of individual doses, making the method more accessible to the medical community in the whole country. This paper describes the efficacy of the fractioning technique as well quality control of the thallium-201 furnished by this Institution, performed in 117 shipments. (author)

  14. Dual myocardial scintigraphic imaging using {sup 123}I-BMIPP and {sup 201}Tl in patients with Duchenne`s progressive muscular dystrophy

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    Sasaki, Akira [Kyorin Univ., Mitaka, Tokyo (Japan). School of Medicine

    1996-03-01

    Dual single photon emission computed tomography (SPECT) was performed in 30 patients with Duchenne`s muscular dystrophy (DMD) using {sup 201} thallium (Tl) for myocardial perfusion {sup 123}I-{beta}-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).

  15. Comparison of exercise-stress single photon emission computed tomography with thallium-201 reinjection and postextrasystolic potentiation to assess myocardial viability in patients with myocardial infarction

    International Nuclear Information System (INIS)

    Myocardial viability was examined in 20 patients with myocardial infarction 24±3 (mean±standard deviation) days after onset. Postextrasystolic potentiation (PESP) was measured by left ventriculography and thallium-201 (Tl) single photon emission computed tomography (SPECT) redistribution was assessed after stress loading and reinjection of Tl. The results were compared with the improvement of left ventricular segmental wall motion after coronary revascularization which was performed successfully in all patients. The uptake of Tl was impaired initially in 41 segments, classified into three groups: normal group, 13 segments with smooth reversion to normal; new fill-in group, 15 segments with a new fill-in after reinjection of Tl; no fill-in group, 13 segments with no fill-in after reinjection. When evaluated by the PESP before coronary revascularization, segmental wall motion was significantly augmented in all segments in the normal group and new fill-in group (p<0.001), but not in the no fill-in group. After coronary revascularization, left ventriculography revealed that segmental wall motion was significantly improved in normal group and new fill-in group, but not in the no fill-in group except for mild improvement in five segments. The sensitivity and specificity of PESP (90% and 93%) and Tl SPECT (80% and 100%) for improvement of segmental wall motion after the coronary revascularization were very high, with the accuracy of either method attaining 87%. This result indicates that both Tl SPECT and PESP are useful for detecting viable myocardium in patients with recent myocardial infarction. (author)

  16. Comparative study of 201Tl-scintigraphic image and endomyocardial biopsy findings in patients with dilated cardiomyopathy

    International Nuclear Information System (INIS)

    201Tl-SPECT image was compared with the findings of endomyocardial biopsy in patients with dilated cardiomyopathies (DCM), and diagnostic value of 201Tl pathy pattern image for fibrosis with DCM was evaluated. Serial 22 patients diagnosed as DCM with endomyocardial biopsy findings were selected for this study (age: 50±17 y.o., male/female=17/5). Patchy pattern of 201Tl-SPECT image was visually classified into 4 stages according to the severity of inhomogeneous defect, and pathologic findings of fibrosis was also classified into 4 according to the severity of fibrosis (0: none, 1: mild, 2: moderate, 3: severe). Ejection fraction calculated from left ventriculography and end-diastolic dimension by echocardiography were also compared with 201Tl-SPECT image. Out of 22 patients, 21 patients (95%) showed fibrosis, and 18 patients (82%) showed patchy pattern with 201Tl-SPECT. Severity of patchy pattern was not in good relation to that of fibrosis (r=0.374). 201Tl image was not related to the function nor dimension. Four autopsy studies revealed a good relation of macroscopic severity, spatial distribution of fibrosis and inhomogeneous 201Tl-defect pattern before death. Patchy pattern of 201Tl-SPECT image will show the myocardial fibrosis in patients with DCM, and is independent of the function. 201Tl-SPECT may show more clinically useful findings of spatial distribution and severity of fibrosis with focal myocardial biopsy. (author)

  17. Differentiation of transiently ischemic from infarcted myocardium by serial imaging after a single dose of 201Tl

    International Nuclear Information System (INIS)

    Myocardial 201Tl uptake and regional blood flow by the microsphere technique were determined in anesthetized dogs undergoing either 20 min of coronary occlusion and 100 min of reperfusion (N = 10) or 120 min of occlusion (N = 4). In both groups, 201Tl was injected intravenously after 10 min of occlusion. In transiently occluded dogs, regional flow at the time of 201Tl administration was reduced to 8 +- 3 percent of normal flow in endocardial layers of the central ischemic zone. After 100 min of reperfusion, flow values were not significantly different from normal. 201Tl activity after reperfusion rose to 56 +- 5 percent of normal, demonstrating that redistribution of the radionuclide occurred during the reflow period. In animals with persistent occlusion, there was a significant relationship between 201Tl uptake and flow (r = 0.95) and no evidence of redistribution of 201Tl during the two hour occlusion period. In another five dogs receiving 201Tl, serial gamma camera images obtained during reperfusion showed increasing uptake of the tracer in apical defects which returned to normal by 4 hours of reflow. Thirteen patients with stable angina received 2 mCi of 201Tl intravenously at peak exercise, and multiple gamma camera images obtained serially. All demonstrated zones of diminished 201Tl uptake 10 min after exercise. Defects which disappeared within 1-6 hours postexercise corresponded to areas supplied by coronary arteries with significant stenoses. Persistent defects were present in regions of old myocardial infarction. Six patients with acute myocardial infarction demonstrated 201Tl myocardial defects which showed no significant change over 6 hours. Redistribution of 201Tl into ischemic myocardium was demonstrated during transient coronary occlusion in dogs and after exercise stress in man

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

    International Nuclear Information System (INIS)

    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)

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

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    Matsumura, Kentaro; Nakase, Emiko; Serizawa, Takashi; Kubota, Shinobu; Kawai, Ichiro; Saito, Takayuki; Haiyama, Tohru (Kyoto Minami Hospital (Japan))

    1992-08-01

    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. Prognostic value of myocardial perfusion single-photon emission computed tomography for the prediction of future cardiac events in a Japanese population. A middle-term follow-up study

    International Nuclear Information System (INIS)

    The prognostic value of rest 201Tl/stress 99mTc-tetrofosmin myocardial perfusion single-photon emission computed tomography (SPECT) for the prediction of future hard cardiac events, including acute myocardial infarction (AMI), unstable angina (UAP) and cardiac death, and the implications for risk stratification has not yet been defined in a Japanese population. The 1,988 patients who underwent rest 201Tl/stress 99mTc-tetrofosmin SPECT were identified and followed up for the occurrence of AMI, UAP and cardiac death. The mean follow-up interval was 26.9±15.8 months. The 142 patients were revascularized within 60 days after SPECT and they were censored from the prognostic analysis. Summed stress score (SSS), summed rest score and summed difference score (SDS) were calculated using a 5-point scoring (Normal: 0, No uptake: 4) and a 20-segment model; 22 cases of myocardial infarction, 31 of UAP and 22 cardiac deaths occurred (1.2%, 1.7% and 1.2%, respectively). Multivariate Cox regression analysis showed that hypertension (Wald 6.37, p<0.05) and SDS (Wald 8.77, p<0.01) were independent predictors of AMI and UAP. Advanced age (Wald 16.0, p<0.001), SSS (Wald 10.9, p<0.01) and SDS (Wald 4.58, p<0.05) were independent predictors of cardiac death. Myocardial perfusion SPECT yields prognostic information toward the identification of acute coronary syndrome and cardiac death. (author)

  1. Thallium-201 single photon emission computed tomography in patients with symptoms of heart disease and non-significant coronary artery lesions

    International Nuclear Information System (INIS)

    Polar presentations of coronary angiograms and myocardial 201Tl SPECT were compared in 44 patients without significant coronary artery disease (201Tl SPECT overlap but are not congruent. Coronary angiography describes morphology of large coronary vessels, whereas 201Tl SPECT contains information of large and small vessel perfusion as well as membrane transport of 201Tl ions. (orig.)

  2. A comparison between terminally radioiodinated hexadecenoic acid (sup(*)I-HA) and 201Tl-thallium chloride in the dog heart

    International Nuclear Information System (INIS)

    The regional myocardial distribution of 131I-16-iodo-9-hexadecenoic acid (131I-HA) and 201Tl-thallium chloride (201TlCl) was determined in normal dogs and after occlusion of a coronary artery. The uptake of 131I-HA was about 20% lower than that of 201TlCl but the ratio 201Tl/131I was the same for the whole myocardium within narrow limit for normal as well as infarcted tissue. The potential of 123I-HA as a radiopharmaceutical for diagnosis of myocardial defects is discussed. (orig.)

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

    International Nuclear Information System (INIS)

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

    International Nuclear Information System (INIS)

    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)

  5. Identification of myocardial viability by exercise/reinjection myocardial single photon emission computed tomography

    International Nuclear Information System (INIS)

    The present study explored the value and limitation of exercise/reinjection myocardial single photon emission computed tomography (SPECT) for assessing myocardial viability in 6 patients with angina pectoris (AP), 19 with acute myocardial infarction (AMI), and 6 with old myocardial infarction (OMI) associated with AP. Exercise (E) early and delayed images were acquired after iv injection of Tl-201 (111 MBq), and the subsequent reinjection (REINJ) images were acquired 15 min after iv reinjection of Tl-201 (37 MBq). Within one week after REINJ scanning, rest (R) early and delayed myocardial SPECT scannings were performed for comparison. E-early, E-delayed, REINJ, R-early, and R-delayed images were quantitatively evaluated by using visual interpretation and Bull's eye display. Visual interpretation of perfusion defects in 20 segments of the myocardium was scored on a 0-4 scale. In Bull's eye display, extent score (ES) and severity score (SS) were calculated from mean±2 SD obtained from normal volunteers; and the degree of improvement for ischemia was expressed as %ES and %SS by dividing each score on E-delayed, REINJ, R-early, and R-delayed images by each of them on E-early images. The group of AMI patients had significantly increased redistribution on REINJ, R-early, and R-delayed images, as compared with the other two groups. Similarly, in this group, both %ES and %SS were significantly improved on these images, as compared with the E-delayed image. The other groups of AP and OMI patients had, however, no significant changes in either %ES or %SS on the E-early, E-delayed, REINJ, R-early, and R-delayed images. Since the solitary use of exercise scanning underestimated myocardial viability in the case of AMI, an additional REINJ scanning may be used in place of rest scanning in terms of its simplicity. (N.K.)

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

    International Nuclear Information System (INIS)

    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)

  7. Quantification of the extent and severity of myocardial ischemia in single-vessel disease using stress-redistribution thallium-201 single-photon emission computerized tomography

    International Nuclear Information System (INIS)

    Single-vessel coronary artery (CA) disease (SVD) is not uniformly benign: long-term prognosis is likely to be related to the extent (E) and severity (S) of myocardial ischemia (isch). To assess the ability of stress thalium-201 (Tl) single photon emission computerized tomography (SPECT) to quantify E and S of isch, the authors studied 15 patients (pts) without myocardial infarction who had SVD (8 LAD, 4 RCA, and 3 LCX). SPECT cuts were analyzed using maximum count circumferential profiles (CPs) which were compared with previously established normal (nl) limits derived from 20 nl pts. E of isch was defined as the % of the CP points falling below nl, S and depth (D) of ischemia respectively expressed the total and the mean % by which the abnormal points fell below normal limits. Although all pts had SVD, the range of E, S and D of isch was wide (0 to 48% and 0 to 38% and 0 to 20% respectively). CA scores (CS) were derived using a 15-point system accounting for the distribution of the diseased CA, location, and degree of stenosis, and collateral supply. CS varied from 1.2 to 8. E and S significantly correlated with CS (r=.74,p=.001, and r=.78, p=.000, respectively). The 6 pts with a D ? .1 had 75% CA stenosis whereas 5 of the 9 pts with D <.1 had only 50-75% stenosis. Thus, the authors conclude that: 1) pts with SVD have highly differing degrees of isch; 2) E, S and D scores from Tl SPECT correlate favorably with the angiographic extent and severity of disease; and 3) SPECT offers potential for quantification of the magnitude of isch and may become a useful, noninvasive prognostic indicator

  8. Hemodynamic significance of diffuse lung uptake of 201Tl in heart diseases

    International Nuclear Information System (INIS)

    Clinical significance of diffuse lung uptake of 201Tl was studied in 244 cases of various heart diseases. The grade of lung uptake of 201Tl was assessed by total lung uptake ratio (L/T), maximal lung uptake ratio (Max/T), lung to myocardium or mediastinum counts ratio (M/H or M/Med) and visual grade. L/T, Max/T, M/H and M/Med were directly correlated with pulmonary arterial pressure (PCW), and inversely correlated with cardiac output (CO) and cardiac index (CI). Among them, L/T was the best index to assess PCW, that was correlated with PCW (r=0.65), CO (r=-0.53) and CI (r=-0.45). The visual grade of 201Tl lung uptake was correlated with L/T, and the increased lung uptake was associated with a higher PCW and a lower CO as well as a lower CI. Diffuse increased lung uptake of 201Tl was observed in 29 of 41 cases (70.7%) with myocardial infarction, 25 of 29 cases (86.2%) with mitral valvular diseases and 9 of 10 cases (90.0%) with combined valvular diseases, in addition, in most cases with left heart failure and cases of NYHA 3 and 4, but that was not rarely observed in cases of NYHA 2 and without left heart failure. In heart diseases, 201Tl myocardial scintigraphy seems to be valuable for detection of left heart failure including pulmonary congestion and interstitial pulmonary edema. Total lung uptake ratio (L/T) may be useful for estimation of PCW, and the visual grade of 201Tl lung uptake may be applicable as routine index for grading of lung uptake of 201Tl. (author)

  9. 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

    International Nuclear Information System (INIS)

    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. In conclusion, BMIPP SPECT imaging is useful for detecting the areas of ischemic myocardium caused by coronary artery stenosis in children with KD. (author)

  10. 201Tl scintigraphy in primary lung cancer

    International Nuclear Information System (INIS)

    Tumor scintigraphy with 201Tl chloride was studied in 153 cases with primary lung cancer, the findings were compared with these of various other respiratory diseases, and some attempts to improve scintigraphic diagnosis were made. Positive results were obtained in not only malignant conditions such as primary lung cancer, metastatic lung tumor and malignant mediastinal tumor, but also benign conditions such as benign thymoma, pneumonia, pulmonary tuberculosis and so on. In primary lung cancer, 139 of 153 cases (90.8 %) had positive results, demonstrating the presence of a primary focus in cases of pleural effusion or atelectasis, and metastatic foci in the hilum and mediastinum. The ratio of the maximal count in primary focus to the upper mediastinum ranged from 0.5 to 4.2 with a mean value ± S.D. of 1.8 ± 0.6, and the ratio of total counts of the primary focus to the administered dose of 201Tl (uptake ratio) ranged from 0.02 % to 0.98 % with a mean value ± S.D. of 0.27 ± 0.18 %. The degree of 201Tl uptake in primary focus correlated with bronchial blood flow and it was higher in cases of T2 and T3 than T1, but no correlation with histological type was found. Joint use of 201Tl scintigraphy and perfusion lung scintigraphy was valuable to improve the anatomical orientation of the image and to assess the significance of the distribution of both radiotracers. Radionuclide angiocardiography with 201Tl contributed to demonstrate vena cava superior syndrome and impairment of the pulmonary perfusion, and to calculate the uptake ratio of 201Tl in various regions including tumor. 201Tl scintigraphy seems to be useful in detecting right ventricular hypertrophy, pericardial effusion, bleomycin pneumonitis and other cardio-pulmonary complications as well as the presence and extent of primary lung cancer. (author)

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

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    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)

  12. Clinical usefulness of 11C-MET PET and 201Tl SPECT for differentiation of recurrent glioma from radiation necrosis

    International Nuclear Information System (INIS)

    The clinical usefulness of L-methyl-11C-methionine positron emission tomography (11C-MET PET) and thallium-201 single photon emission computed tomography (201Tl SPECT) for distinguishing glioma recurrence from radiation-induced changes was evaluated. Ten patients with lesions highly suggestive of recurrent glioma on magnetic resonance imaging underwent 11C-MET PET and 201Tl SPECT studies. Two patients were examined twice, so a total of 12 studies were performed. The clinical diagnoses were five recurrent gliomas and seven radiation necrosis. The five recurrent gliomas appeared as increased uptakes on both 11C-MET PET and 201Tl SPECT scans. Four of the seven radiation necrosis lesions also appeared as increased uptakes on the 201Tl SPECT scans. In contrast, only one radiation necrosis appeared as increased uptake on the 11C-MET PET scans. There was no significant difference in 201Tl SPECT indices between radiation necrosis and tumor recurrence, but the ratio of the differential absorption ratio of tumor tissue to that of the homologous contralateral gray matter in PET of recurrent glioma was significantly higher than that of radiation necrosis. 11C-MET PET is superior to 201Tl SPECT for the differentiation of tumor recurrence from radiation necrosis and delineation of the extent of the tumor. (author)

  13. Diagnostic significance of positive I-123 BMIPP despite negative stress Tl-201 myocardial imaging in patients with suspected coronary artery disease

    International Nuclear Information System (INIS)

    There is frequently discordance in the interpretation of myocardial single-photon emission computed tomography images using both rest iodine-123 15-(p-iodophenyl)-3-(R, S) methylpentadecanoic acid (BMIPP) and stress thallium-201 (201Tl); that is, negative BMIPP vs positive 201Tl studies. However, little attention has been paid to reverse discordance (ie, positive BMIPP despite negative stress 201Tl). In the present study 105 consecutive patients with suspected coronary artery disease (CAD) who underwent both rest BMIPP and stress 201Tl imaging were evaluated. No patient with previous myocardial infarction was included. Scintigraphic studies revealed that BMIPP was in concordance with 201Tl in 71 patients: both were positive in 38 and negative in 33, whereas both were discordant in 20 and reverse discordant in 14. In patients with reverse discordance, the pattern of BMIPP abnormality was segmental in 8 and spotty in 6; the former was related to coronary territory. Based on the BMIPP findings and clinical symptoms, 7 patients with positive BMIPP despite negative 201Tl underwent coronary angiography: 3-vessel CAD was found in 3 patients, 2-vessel CAD in 1, coronary spasm in 2, and insignificant lesions in 1. In the remaining 7 patients, no cardiac event was observed during 2-year follow-up. In patients showing positive BMIPP despite negative 201Tl, a segmental BMIPP perfusion abnormality indicates a high likelihood for CAD, despite normal stress 201Tl imaging. Thus, adding BMIPP to 201Tl imaging may help to better identify patients with significant CAD, including multivessel disease. (author)

  14. Thallium-201 myocardial single photon emission computed tomography after isoproterenol infusion in diagnosing ischemia heart disease

    International Nuclear Information System (INIS)

    Patients with obstructive atherosclerotic disease of the peripheral arteries are often unable to undergo a standard Treadmill test for evaluation of concomitant coronary artery diseases. To establish an alternative method of testing, 27 patients had intravenous infusion of isoproterenol, up to 1.0 ?g/kg, in conjugation with myocardial thallium-201 single photon emission computed tomography (SPECT). All underwent coronary angiography. Thallium-201 myocardial SPECT after isoproterenol infusion was found to have 100 % sensitivity and 100 % specificity for detecting coronary artery diseases (stenotic or occluded coronary arteries with or without myocardial infarction) and 87 % sensitivity and 100 % specificity for detecting stenotic coronary arteries with viable regional myocardium. No major complication was experienced during and after this study. It is concluded that serial thallium-201 myocardial SPECT after isoproterenol infusion is safe, reliable and useful for detecting coronary artery disease when standard exercise test is not feasible. (author)

  15. 201Tl scintiscanning of the myocardium following radiotherapy of the thoracic region

    International Nuclear Information System (INIS)

    40 patients were examined by 201Tl scintiscanning after radiotherapy of the thoracic region in breast cancer and metastasizing testicular tumors, resp. The results allowed to evaluate the clinical and electrocardiographic findings in 105 follow-up patients. From 40 patients with the greater part having no cardiac symptoms, 22 revealed irreversible 201Tl fixation disturbances and 10 storage deficiency under stress with repletion after rest. These findings are interpreted as myocardial fibrosis or ischemic reaction due to radiotherapy and conclusions for follow-up checks are recommended

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

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    Kurata, Chinori; Uehara, Akihiko; Sugi, Toshihiko; Yamazaki, Keisuke [Hamamatsu Univ. School of Medicine, Shizuoka (Japan); Tawarahara, Kei; Mikami, Tadashi; Matoh, Fumitaka; Odagiri, Keiichi

    2000-06-01

    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 {sup 201}Tl 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 {sup 201}Tl 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 {sup 201}Tl 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 {sup 201}Tl SPECT is useful for evaluating myocardial ischemia even in the elderly, but exercise electrocardiography has limitations such as lower specificity in the elderly than {sup 201}Tl SPECT. (author)

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

    International Nuclear Information System (INIS)

    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)

  18. Examinations of ischemic heart diseases by sup(201)Tl perfusion under stress

    International Nuclear Information System (INIS)

    Scintigraphic examinations of the myocardial perfusion was carried out by means of sup(201)Tl perfusion. The results obtained in 23 cases are correlated with data of coronarography carried out subsequently. The sensitivity of the new non-invasive technique was found to be 77%, its specificity 90%. (L.E.)

  19. Quantitative analysis of myocardial tracer distribution in patients with ischemic heart disease. Comparison of 201Tl and 123I-15-(p-iodophenyl)-3-methylpentadecanoic acid (BMIPP)

    International Nuclear Information System (INIS)

    Quantitative assessment of myocardial tracer uptake in stress-delayed thallium and resting BMIPP imaging was performed in 24 patients with coronary artery disease. Each distribution was displayed on the bull's eye polar map and % uptake of each distribution was calculated as a mean value in 9 myocardial segments on the polar map. Redistribution index (% delayed uptake minus % stress uptake on thallium images) and discordance index (% delayed thallium uptake minus % BMIPP uptake) were also calculated. Each parameter was compared to the visual uptake score and wall motion score on contrast left ventriculography. Excellent correlations were obtained between % uptake and the uptake score in each tracer. The % thallium and BMIPP uptake also correlated with regional wall motion score. Furthermore, a significant correlation was observed between redistribution and discordance indexes in the mildly hypoperfused segments. These data indicate that the quantitative analysis of thallium and BMIPP distributions seems to be valuable to understand relationship between perfusion and regional wall motion. The discordant BMIPP uptake may represent asynergic but viable segments. However, several important factors, such as attenuation factor should be also taken into consideration for such quantitative analysis. (author)

  20. Clinical evaluation of single-photon emission computed tomography for Tl-201 myocardial imaging

    International Nuclear Information System (INIS)

    Single-photon emission computed tomography (SPECT) for Tl-201 myocardial imaging using a rotating gamma camera was evaluated for clinical diagnostic efficacy of myocardial infarction. Thirty-three cases with prior myocardial infarction and 28 cases without myocardial infarction were injected with 2 - 4 mCi of Tl-201 at rest. Planar imaging was performed for 5 views (ANT, LAO-30, 45, 60, L-LAT) and followed by SPECT. Overall time of the studies was within one hour. Results were as follows: (1) Sensitivity, specificity and overall accuracy for myocardial infarction diagnosis of SPECT system showed 96.9%, 78.6% and 88.5% respectively. In comparison with planar imaging, SPECT significantly improved sensitivity, however decreased specificity and slightly improved accuracy. (2) Overall interpretation of transaxial, coronal and sagittal images were required for the detection of myocardial infarction. (3) SPECT images showed more clearly findings of infarction than planar imaging and extension of myocardial infarction on SPECT images showed relatively well correlation with ECG diagnosis. (author)

  1. A comparison of prone SPET and left lateral (decubitus) planar imaging for inferior wall attenuation artefact in 201Tl myocardial imaging

    International Nuclear Information System (INIS)

    Full text: Inferior wall attenuation artefacts are a major problem in supine SPET (S-S) myocardial perfusion imaging. SPET imaging with the patient lying in the prone position (P-S) and left lateral planar imaging with the patient lying in the right lateral decubitus position (LL) ameliorate this artefact. This study attempts to define the clinical role of P-S and LL imaging in characterizing S-S inferior wall defects. 21 patients with an inferior wall defect on S-S then had LL and rapid P-S imaging. All images were performed with a GE Optima NX gamma camera using GENIE acquisition and processing. All SPETs used 16 stops (32 frames) through 90 deg, with 40 s per stop for SS and 14 s per stop for P-S. LL images were acquired for 150 s. All images were assessed for adequacy and inferior wall scored for 0 = no, 1 mild, 2 moderate and 3 = severe defects. Statistical analysis was performed using the Wilcoxon rank sum test for matched pairs. All images were adequate for analysis. Significantly fewer defects were seen in P-S vs S-S, LL vs S-S (P 0.88); however; there was a difference (P < 0.05) in the subgroup (n = 7) with moderate defects on S-S imaging but no LL defect. In conclusion, most inferior wall defects seen on S-S imaging can be attributed to either attenuation or true perfusion defects with the use of LL imaging. Prone imaging may only be helpful where the inferior defect is of moderate severity but no LL defect is seen

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

    Directory of Open Access Journals (Sweden)

    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.

  3. 201Tl-redistribution analysis in early and delayed myocordial scintigrams of patients with coronary heart disease (CHD)

    International Nuclear Information System (INIS)

    Scans were performed on 8 healthy subjects and 25 with coronary heart disease proven by angiography and ventriculography including 6 with previous myocardial infarction at rest, exercise, and 1 and 2 h after exercise. Data were collected by a gamma camera interfaced to a data collection system. In healthy subjects 201Tl distribution was homogeneous at rest and after exercise, the count rate ranging between 100% - as set in the region of maximum - and 80% over other regions of myocardium. In 19 patients with coronary heart disease it was uniform only at rest; 6 patients with previous myocardial infarction had locally diminished 201Tl uptake even at rest. In patients with coronary heart disease without previous myocardial infarction, scans made immediately after exercise showed significant 201Tl hypofixation in region of minimum, the count rate of which was less than 80% of the count rate as determined over region of maximum, 201Tl uptake. Scans made 1 and 2 h after exercise had filling-in of 201Tl within the region of minimum the count rate of which returned to the normal range of at least 80% of the count rate measured over region of maximum uptake. This return to resting distribution was called 201Tl redistribution. Six patients with coronary heart disease and previous myocardial infarction had 201Tl defects larger after exercise than at rest, without redistribution being observed. Redistribution in late postexercise scans is a sign of reversible ischemia in coronary heart disease. Scans at rest may be omitted in coronary heart disease, because transient ischemia is undetectable, unless spontaneous angina occurs during scan procedure. (orig.)

  4. Computer-aided diagnosis in two-phase 201Tl-SPECT of thoracic lesions

    International Nuclear Information System (INIS)

    Aim: the retention index, a traditionally quantitative analysis of two-phase 201Tl single photon emission computed tomography (SPECT) of the chest, is manually calculated by experienced physicians from comparable 2-D ROI. However, a 3-D ROI would provide more information than a 2-D ROI extracted from a single frame of SPECT. We propose a new diagnostic system, computer-aided diagnosis (CAD), to automatically detect suspicious lesions as 3-D objects on chest 201Tl-SPECT, and assist the physician in interpreting these images. Patients, methods: seventy patients with thoracic lesions and confirmed diagnoses were enrolled to test this automatic CAD system. The reliability of the CAD system in detecting lesions as 3-D objects was compared to the 2-D ROI of 201Tl-SPECT found by the manually visualized method. Furthermore, we also proposed a novel index, the retention index using the heart (RIH), to differentiate high retention (slow clearance, increasing target to heart ratio) as a criterion for a malignant lesion, from low retention (faster clearance, small or no increase of the target to heart ratio) for benign lesions. Results: the CAD system can achieve a detection rate of 100% in automatically searching for thoracic lesions in 201Tl-SPECT. In diagnostic performance, the CAD system with the RIH of comparable 3-D objects has an area under the ROC curve of 0.86, higher than the 0.78 of the traditional RI method (p = 0.198). Conclusion: the CAD system of two-phase 201Tl-SPECT is a promising tool for detecting and diagnosing thoracic lesions with a diagnostic accuracy of 0.81. (orig.)

  5. Usefulness of dynamic 201TlCl SPECT for differential diagnosis of ring-enhancing brain lesions

    International Nuclear Information System (INIS)

    Glioblastoma (GB), metastatic brain tumor (ME), and brain abscess (AB) show ring enhancement on imaging, and their differentiation is difficult. We performed dynamic 201TlCl SPECT in patients with these 3 diseases, and investigated the diagnostic usefulness of differences in their accumulation dynamics. The subjects were 41, 37, and 11 patients with GB, ME, and AB, respectively, who underwent single photon emission tomography (SPECT). Dynamic scan every minute for 15 minutes was initiated immediately after the administration of 201TlCl. All data for the 15 minutes were added up and designated as static data, and the thallium index (TL index) was calculated from the ratio of uptake in the tumorous region to that in the contralateral normal brain region. Data per minute were summed every 3 minutes and designated as dynamic data, and the time-activity ratio curve (TARC) was drawn using the tumor/contralateral normal brain uptake ratio. The TARC was approximated to a linear function, and its slope was compared between the 3 disease groups. The TL index was 5.16±1.95 (mean±standard deviation (SD)) in GB, 3.63±1.71 in ME, and 2.60±1.52 in AB, showing a greater uptake in GB than in ME and AB (p201TlCl uptake in GB (p201TlCl uptake in tumors by dynamic 201TlCl SPECT may be a simple, useful evaluation method for the differential diagnosis of ring-enhancing brain lesions. (author)

  6. Comparison of myocardial Perfusion imaging by thallium-201 single-photon emission computed tomography with SUNY4001 (adenosine) and exercise. Crossover clinical trial at multi-center

    International Nuclear Information System (INIS)

    We compared the ischemic diagnosis ability and adverse events of 201Tl myocardial perfusion imaging with SUNY4001 (adenosine) stress to that with exercise (ergometer) stress both on random crossover trial. Thirty one known or suspected chronic stable angina patients who are able to exercise and 10 healthy volunteers were enrolled for the trial. The early and delayed images were obtained by SPECT imaging. The concordance of diagnoses [ischemia vs. no ischemia] between the two types of stresses was 97.3% (36/37) [Kappa: 0.9068]. The sensitivity and specificity based on the exercise test were 100% (6/6) and 96.8% (30/31) respectively. The incidence of adverse events caused by SUNY4001 and the exercise were 44.7% (17/38) and 52.6% (20/38), respectively. Major adverse events caused by SUNY4001 were blood pressure (BP) decrease, flushing and headache. And those by exercise were ST decrease, dyspnea and chest pain. None of the adverse events required the intervention or caused life-threatening complication in the trial. The trial showed that the ischemic diagnosis ability and safety of 201Tl scintigraphy with SUNY4001 stress are almost equal to those of the exercise stress that is considered as the standard stress method. We concluded that 201Tl imaging with SUNY4001 is safe and useful for detecting ischemic heart disease, especially for patients unable to exercise adequately. (author)

  7. Myocardial infarct quantification in the dog by single photon emission computed tomography

    International Nuclear Information System (INIS)

    Radionuclide techniques for sizing acute myocardial infarction have been hampered by the intrinsic limitations of the scintillation camera. Emission computed tomography can overcome these limitations. Single photon emission computed tomograms of the distribution of technetium-99m pyrophosphate in acute anterior and posterior infarcts were obtained in 16 dogs after death. Tomograms were also obtained in 10 dogs during life without gating. The size of the infarcts was determined by staining gross sections of the heart with nitro blue tetrazolium, dissecting out the infarcted tissue and weighing it. Infarct sizes were determined from the tomographic images and compared with the measured infarct sizes. Good images showing the location and three-dimensional extent of the infarcts were obtained in all dogs. The measured and calculated infarct sizes correlated well (r = 0.85). Comparison of the calculated sizes in the living (non-gated) and dead (physiologically gated) animals showed reasonable agreement (r = 0.87). Single photon emission computed tomography is a feasible and useful technique for localizing and sizing acute myocardial infarctions

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

    International Nuclear Information System (INIS)

    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

  9. Assessment of left ventricular function by electrocardiogram-gated myocardial single photon emission computed tomography using quantitative gated single photon emission computed tomography software

    International Nuclear Information System (INIS)

    Electrocardiogram (ECG)-gated myocardial single photon emission computed tomography (SPECT) can assess left ventricular (LV) perfusion and function easily using quantitative gated SPECT (QGS) software. ECG-gated SPECT was performed in 44 patients with coronary artery disease under post-stress and resting conditions to assess the values of LV functional parameters, by comparison to LV ejection fraction derived from gated blood pool scan and myocardial characteristics. A good correlation was obtained between ejection fraction using QGS and that using cardiac blood pool scan (r=0.812). Some patients with myocardial ischemia had lower ejection fraction under post-stress compared to resting conditions, indicating post-stress LV dysfunction. LV wall motion and wall thickening were significantly impaired in ischemic and infarcted myocardium, and the degree of abnormality in the infarcted areas was greater than in the ischemia area. LV functional parameters derived using QGS were useful to assess post-stress LV dysfunction and myocardial viability. In conclusion, ECG-gated myocardial SPECT permits simultaneous quantitative assessment of myocardial perfusion and function. (author)

  10. Effects of ouabain on 201Tl and 99mTc MIBI kinetics in rat myocardium

    International Nuclear Information System (INIS)

    The aim of this study was to investigate the effect of ouabain (inhibitor of Na-K ATPase) in the myocardial uptake and clearance of 201Tl and 99mTc MIBI using rats. Time activity curves of three groups were measured by CsI miniature detector for 15 min after the administration of each radiopharmaceutical. Groups were divided as follows: 1) control group (CON group), 2) early phase 15 min after the administration of ouabain (OU15 group), and 3) late phase 120 min after the administration of ouabain (OU120 group). Main organs of rats including myocardium were resected at 1 min and 15 min after the administration of 201Tl or 99mTc MIBI under the anesthesia of pentobarbital sodium. The uptake (%ID/g) of 201Tl or 99mTc MIBI was measured by well type scintillation counter. The uptake of 201Tl of OU15 group was significantly higher than CON group (OU15: 10.81±1.90, CON: 1.86±0.42) and cleared more rapidly. On the contrary, OU120 group showed lower uptake (1.70±0.21) and slower clearance than OU15 group. Time activity curve of OU15 group indicated the accelerated washout compared with CON group. However, OU120 group showed significantly the reduced washout (CON group: 19%, OU15 group: 22%, OU120 group: 9%). On the other hand, the uptake and time activity curves of 99mTc MIBI were not influenced by ouabain administration. In conclusion, myocardial uptake and clearance of 99mTc MIBI were not related to Na-K ATPase activity, while those of 201Tl were markedly influenced by Na-K ATPase. (author)

  11. Evaluation of exercise thallium-201 myocardial single photon emission computed tomography in silent myocardial ischemia

    International Nuclear Information System (INIS)

    To evaluate the diagnostic significance of exercise Tl-201 myocardial SPECT in silent myocardial ischemia, 41 patients with angiographically-proven coronary artery disease (27 effort angina, 14 postinfarction angina) were tested using this method. Double product (blood pressure x heart rate) during exercise was used as a hemodynamic parameter. Thirty-two projections were obtained throughout 180 degrees by a rotating gamma camera, immediately, and four hours after exercise. Myocardial Tl-201 washout rate of the entire left ventricle was presented in two-dimensional polar function maps. Normal lower limit of myocardial Tl-201 washout rate was defined as mean-2SD of normals, and the region with a washout rate lower than normal was defined as an ischemic region. The location of myocardial ischemia was visually determined using a Bull's eye polar map. The ischemic size was quantified by the defect volume ratio (ratio of the ischemic myocardium to total myocardium). Coronary lesions were quantitatively assessed by the Pujadas score using coronary angiography. Results were as follows: There was no significant difference between painful myocardial ischemia and silent myocardial ischemia according to double product and the Pujadas scores. In most silent ischemia, the region of the reduced washout rate was in the inferior or lateral area of the Bull's eye polar map, whereas it was in the anterior area in painful ischemia . The defect volume ratio indicating the extent of ischemia was smaller in silent ischemia than in painful ischemia. In conclusion, the ischemic location and size may be contributing factors in silent myocardial ischemia. (author)

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

    International Nuclear Information System (INIS)

    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.)

  13. Abnormal 201Tl limb scan due to unilateral tremor

    International Nuclear Information System (INIS)

    A abnormal intra- and interextremity distribution pattern on 201Tl was observed on the limb scan of a patient with a unilateral tremor. This is ascribed to the increased blood flow in the muscles responsible for the tremor. The suggestion is made that the existence of tremor should be considered as a possible explanation for unexpected abnormalities on 201Tl limb scintigrams

  14. Comparative study of 201Tl reinjection tomography and combined use of 13N-ammonia and 18F-fluorodeoxyglucose positron emission tomography for detection of viable myocardium

    International Nuclear Information System (INIS)

    Objective: To compare the clinical value of 201Tl reinjection tomography and combined use of 13N-ammonia (NH3) regional myocardial perfusion and 18F-fluorodeoxyglucose (FDG) positron emission tomography transfer function and for the myocardium. Methods: The authors performed exercise 201Tl SPECT (Tl SPECT) on 20 patients with myocardial infarction and obtained standard 201Tl exercise-redistribution images. 201Tl was reinjected immediately after redistribution study, and the images were then acquired as also. The 20 patients also underwent PET imaging with 13N-NH3 and 18F-FDG (NH3-FDG PET) within one week of the above study. Vertical and horizontal long axis cuts were divided into nine segments, and uptakes of radioisotope were evaluated into four classes visually (Defect score, DS) (0:normal uptake, 3:severely reduced). Quantitative evaluation was performed on the vertical and horizontal long axis cuts of 201Tl redistribution, reinjection and FDG PET images using regions of interest. The relative myocardial 201Tl uptake and 18F-FDG uptake (% ID) were expressed as the percentage of this reference region accounted for of the maximal counts. Results: In 48 segments identified as viable by the NH3-FDG PET images, 45 (93.8%) segments were also identified as viable by the 201Tl redistribution imaging. Of 24 segments with severe irreversible defects on the 201Tl redistribution imaging, 87.5% of the segments were concordantly confirmed by 201Tl reinjection and NH3-FDG PET images with 37.5% identified as viable and 50% identified as scar. There was no significant difference in the average % ID, furthermore, regression analysis revealed a high positive correlation in the segmental % ID between 201Tl reinjection and FDG PET images in the 61 segments with myocardial infarction (r = 0.722). Conclusions: The results show that 201Tl reinjection tomography is of similar accuracy with NH3-FDG PET for detection of viable myocardium and possess important clinical practice value

  15. The assessment of fatty acid metabolism using single photon emission computed tomography with Iodine-123-p-iodophenyl-3-(R,S)-methyl pentadecanoic acid (BMIPP) in patients with subacute myocardial infarction. Comparison with left ventricular regional wall motion and myocardial perfusion with Tl-201

    International Nuclear Information System (INIS)

    Fatty acid metabolism, myocardial perfusion and left ventricular wall motion in the subacute stage of myocardial infarction were investigated in 42 patients (33 males and 9 females). At about 3 weeks after crisis, SPECTs (single photon emission computed tomography) were carried out at 20 min after intravenous injection of 123I-BMIPP (4 mCi) for 15 min and at 6 min after 201Tl (2 mCi) using Toshiba GCA-9300A/HG apparatus which having 3 detectors. Reconstruction was done on the short axis, vertical long axis and transaxis of the left ventricle. Myocardium was divided to 7 regions according to AHA classification. Wall motion was evaluated by echocardiography, which was also used for identification of the infarcted area together with electrocardiograph. Patients were found to have a good (A: 24 patients) and impaired (B: 18) wall motion, who were further divided to those undergone with (1) or without (2) the re-perfusion therapy. Following statistically significant difference was found: For BMIPP accumulation, B>A and B2>others and for Tl score, B>A and B2>others. Dissociation between BMIPP and Tl scores of >1 was not found in all groups. In A2 group, a dissociation with a significantly lower BMIPP score (<3) than B2 was recognized. It was concluded that the degree of the ischemic lesion and recovery of wall motion of myocardium of subacute infarction stage can be reflected by the fatty acid metabolism, perfusion and dissociation. (K.H.)

  16. Prediction of left ventricular dilatation with thallium-201 SPET imaging after primary angioplasty in patients with acute myocardial infarction

    International Nuclear Information System (INIS)

    Progressive ventricular dilatation is an important prognostic factor in patients with acute myocardial infarction. We evaluated clinical, angiographic, echocardiographic and thallium-201 single-photon emission tomography (SPET) imaging variables predictive of the change in left ventricular volume during a 7-month follow-up period after primary angioplasty in patients with acute myocardial infarction. Thirty-six patients with first acute myocardial infarction treated with primary angioplasty within 12 h of onset underwent 201Tl SPET imaging (5.8±2.1 days after angioplasty). Changes in left ventricular volume were assessed over the 7-month period. The left ventricle dilated significantly after angioplasty (P201Tl uptake 2=0.41, P201Tl uptake 2 with positive and negative predictive values of 85% (17/20) and 75% (12/16), respectively. It is concluded that, following primary angioplasty in patients with acute myocardial infarction, the extent of myocardial infarction assessed by 201Tl SPET can identify those who will develop ventricular dilatation during the subsequent 7 months. (orig.)

  17. The optimum technique for 201Tl tomography of myocardium: an investigation using phantoms

    International Nuclear Information System (INIS)

    Rotating gamma-camera tomography is used for 201Tl perfusion imaging to detect myocardial ischaemia or infarction. Variables which can affect the utility of the images include acquisition time, collimator sensitivity and resolution, spatial filtering, reconstruction matrix and display parameters. An 'Iowa' design myocardial phantom containing 201Tl, with a defect representing an unperfused area, was used to study the effect of these variables. Receiver operator characteristic (ROC) curves and contrast ratios indicated that filtering the acquisition data with a count-dependent (Metz) filter before reconstruction and using a narrow slice width gave best results. No single collimator was superior for all four defect locations investigated but low-energy general purpose and high-resolution collimators were preferred to those with greater sensitivity. Reducing acquisition time by a factor of four compared with that for routine patient imaging affected contrast ratio, uniformity and area under ROC curves insignificantly, provided the optimum reconstruction was used. Displaying tomographic sections in colour gave no improvement in ROC curves over monochrome images. Data acquisition time or administered 201Tl radioactivity might therefore be reduced below the 25 min and 80 MBq often used for patient studies. (author)

  18. Identification of viable myocardium using 99mTc-tetrofosmin scintigraphy. Comparison with 201Tl redistribution-reinjection images

    International Nuclear Information System (INIS)

    The purpose of this study was to clarify the diagnostic value of identifying viable myocardium using 99mTc-Tetrofosmin scintigraphy. Twenty-one patients with chronic coronary artery disease were studied using 201Tl exercise myocardial scintigraphy with reinjection and 99mTc-Tetrofosmin exercise myocardial scintigraphy. All patients had a history of old myocardial infarction. For 99mTc-Tetrofosmin scintigraphy, 222 MBq of 99mTc-Tetrofosmin was injected during exercise, and exercise images were obtained 20 min thereafter. Three hours later, 666 MBq of 99mTc-Tetrofosmin was injected at rest, and images were obtained 40 min and 220 min later. Myocardial viability in the 99mTc-Tetrofosmin scintigraphy was estimated as fill-in findings (FF) or over 50% of %RI uptake (%TF) in the rest image. Myocardial viability in the 201Tl scintigraphy was estimated as redistribution (RD), full-in findings in the reinjection image (FR) or over 50% of %RI uptake in the reinjection image (%TL). Sixteen of the 21 patients (76%) who underwent 201Tl scintigraphy (RD 10, FR 3, %TL 3 cases) and 15 of the 21 patients (71%) who underwent 99mTc-Tetrofosmin scintigraphy (FF 11, %TF 4 cases) had viable myocardium in the infarcted area. A comparison between the 99mTc-Tetrofosmin rest images obtained 40 min after the injection and that of 220 min revealed no redistribution findings. The %RI uptake of the infarcted area in the resting 99mTc-Tetrofosmin image (47±16%) was slightly lower than that in the 201Tl reinjection image (52±16%). In conclusion, viable myocardium was as clearly identified by 99mTc-Tetrofosmin, as by 201Tl scintigraphy. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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 denoising methods studied. In conclusion, the multi-scale platelet denoising method applied on raw projection images provides more efficient noise reduction while preserving image quality in a myocardial phantom SPECT imaging as compared to the Butterworth filter applied either on projection or reconstructed images. However, this trend in favour of the platelet denoising method was not observed on clinical data reconstructed either without or with attenuation correction

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

    Science.gov (United States)

    Skiadopoulos, S.; Karatrantou, A.; Korfiatis, P.; Costaridou, L.; Vassilakos, P.; Apostolopoulos, D.; Panayiotakis, G.

    2009-10-01

    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 denoising methods studied. In conclusion, the multi-scale platelet denoising method applied on raw projection images provides more efficient noise reduction while preserving image quality in a myocardial phantom SPECT imaging as compared to the Butterworth filter applied either on projection or reconstructed images. However, this trend in favour of the platelet denoising method was not observed on clinical data reconstructed either without or with attenuation correction.

  4. Leg 201Tl-SPECT in chronic exertional compartment syndrome

    International Nuclear Information System (INIS)

    Leg 201Tl-SPECT in chronic exertional compartment syndrome Background: The chronic exertional compartment syndrome is one of the most frequent origins regarding leg pain due to sport training. The diagnosis can be established by invasive compartment pressure measurement. The aim of this study is to evaluate the role that could have 201Tl-SPECT for patients with suspicion of compartment syndrome. Patients and methods: 51 leg 201Tl-SPECT exams were performed (exercise - and rest without reinjection) in 49 patients; 28 had compartment syndrome confirmed by pressure measurement. About 100 MBq of 201Tl were injected during exercise, when pain appeared or at least after 25 minutes exercise. We studied mean percentages of level uptake for each compartment, referred to the maximal uptake of both legs. Results: 47 compartments were concerned by compartment syndrome and 361 compartments were not. Scintigraphic patterns in compartments are reversible ischaemia (45%), uptake stability (36%) or reverse redistribution (19%); these patterns are not linked to compartment syndrome. However, there is a significant difference of rest 201Tl level uptake between compartments with and without compartment syndrome and a significant correlation between muscular pressure measurement and rest level uptake. Conclusion: 201Tl-SPECT shows that only ischaemia does not explain compartment syndrome. Moreover, it allows to predict pressure variation during exercise but it does not offer any interest in order to select patients for muscular invasive pressure measurement. (author)

  5. Microcystic meningioma with late-phase accumulation on Thallium-201 single-photon emission computed tomography. Case report

    International Nuclear Information System (INIS)

    Microcystic meningiomas are rare but benign brain tumors. Previous reports have shown that Thallium-201 single-photon emission computed tomography (201Tl SPECT) demonstrated a higher late-phase accumulation of 201Tl in malignant or recurrent meningiomas than in nonaggressive meningiomas. No study has reported 201Tl SPECT findings in microcystic meningiomas. We here describe a case of a microcystic meningioma with a high 201Tl SPECT retention rate in a 62-year-old woman who complained of headache. Computed tomography revealed an intracranial tumor in the right frontal lobe. Moreover, 201Tl SPECT revealed a high uptake of 201Tl in the tumor, which was particularly prominent in the delayed phase. The uptake index on an early image was 1.46 and that on a delayed image was 1.35. Therefore, the retention index was 0.92. After 2 years of tumor growth, we performed successful radical resection, and histological examination revealed the presence of a microcystic meningioma. Therefore, we concluded that 201Tl SPECT may be useful for the preoperative diagnosis of microcystic meningiomas and that late-phase accumulation of 201Tl is not a specific finding of malignant brain tumors. Therefore, we need to be careful in the evaluation and judgment of high retention in a delayed image of 201Tl SPECT. (author)

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

    International Nuclear Information System (INIS)

    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)

  7. Value of 123I-BMIPP scintigraphy in patients with ischemic heart disease. Comparison with exercise 201Tl SPECT

    International Nuclear Information System (INIS)

    To evaluate 123I labeled beta-methyl-branched fatty acid (BMIPP) myocardial uptake at rest in the segment with and without stress induced ischemia in patients with coronary artery disease, 123I-beta-methyl-branched fatty acid myocardial scintigraphy was performed at rest and was compared with the findings of stress-reinjection 201Tl myocardial scintigraphy in 31 patients with coronary artery disease. In 159 ischemic myocardial segments, equally decreased uptake on both reinjection 201Tl and fatty acid images was observed in 64 segments, more severely decreased uptake of fatty acid in 76 segments, and more severely decreased uptake of reinjection thallium in 19 segments. On the other hand, in 53 non-reversible defects, each patterns was observed in 41, 3, and 9 segments respectively. When comparing the ischemic segments with more reduced uptake of fatty acid than reinjection thallium (Group 1) and the ischemic segments with equally or less reduced fatty acid uptake than reinjection thallium (Group 2), wall motion was more severely impaired in Group 1 than in Group 2 (severe hypo- to dyskinesis was present in 32 of 54 segments in group 1 and in 21 of 75 segments in group 2, p201Tl in the segments with stress induced ischemia and wall motion was more impaired in these segments. BMIPP myocardial imaging may provide information on metabolic alterations at rest independent of perfusion abnormalities in patients with coronary artery disease. (author)

  8. The most suitable parameter to distinguish brain tumor using 201Tl-chloride and SPECT

    International Nuclear Information System (INIS)

    We performed 201Tl single photon emission CT (SPECT) studies on 62 patients with brain tumors prior to any therapy for the tumor. Ten lesions of ope-scar and 17 patients without brain tumor were also studied. The SPECT imaging was initiated 5 min (early image) and 4 hour (delayed image) after injection with 74 MBq of 201Tl-chloride. For a semi-quantitative analysis, we used the ratio of delayed count density to the early count density of the tumor (Td/Te), the ratio of tumor to normal brain tissue (Te/Te) on the early SPECT and the index of T/B ((Td/Te)/(Bd/Be)). Delay to early ratio of 34 normal brain tissue (Bd/Be) was 1.22±0.15 and tended to decrease with the age. The Td/Te ratio of meningioma and region of operation scar was about 0.75 which was less than that of normal brain tissue. In 31 patients with astrocytic tumor, Td/Te ratio was clearly higher in poorly differentiated tumor than in well differentiated one. The index of Td/Te ratio was superior to Te/Be or T/B ratio for differentiating brain tumor and grading astrocytic tumor. (author)

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

    Directory of Open Access Journals (Sweden)

    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.

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

    International Nuclear Information System (INIS)

    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

  11. Use of ECG-gated single-photon emission tomography to assess the evolution of perfusion after acute myocardial infarction

    International Nuclear Information System (INIS)

    Serial improvement in myocardial perfusion images from the acute or subacute to the chronic stage of acute myocardial infarction (AMI) has been attributed to improved coronary microcirculation or cell function after acute ischaemia and reperfusion. However, conventionally used non-gated imaging cannot eliminate the effect of improved regional contraction. We studied the possibility that such scintigraphic improvement reflects the functional recovery by using ECG-gated myocardial perfusion imaging with technetium-99m sestamibi. Nineteen AMI patients who received acute reperfusion therapy underwent ECG-gated myocardial single-photon emission tomography (SPET) in the subacute and chronic stages. Serial changes in regional image count distributions were analysed on the non-gated, end-diastolic (ED) and end-systolic (ES) images by using segmental mean percent peak activity (MPA) and ?MPA (MPA in chronic stage - MPA in subacute stage) on bull's-eye polar maps. These changes were compared with those in regional wall motion on biplane left ventriculography (LVG) from the acute (just after reperfusion) to the chronic stage. During the follow-up, regional wall motion remained the same in 42 (group A) but improved in 17 (group B) of the 59 ischaemically compromised segments. MPA showed no improvement in group A but significant improvement in group B on the non-gated and ES images (P<0.0001 and P<0.001, respectively). However, MPA on the ED images showed no improvement in either group. In the follow-up study of AMI, the scintigraphic improvement documented on the non-gated myocardial images appears to be mainly related to the recovery of wall thickening and not to a real improvement in myocardial perfusion. Therefore, ECG-gated myocardial imaging, which enables simultaneous assessment of changes in perfusion and contraction, is preferable to conventional non-gated imaging for follow-up of AMI. (orig.)

  12. Preparation of 201Tl for medical use from 203Tl enriched target

    International Nuclear Information System (INIS)

    Cyclotron production of 201Tl from 203Tl enriched targets has made possible the preparation of 201Tl for medical use. The optimal proton activation conditions, a new radiochemical separation and analytical controls of 201Tl are described in detail. (author)

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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.)

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

    International Nuclear Information System (INIS)

    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)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  17. Single-photon emission computerized tomography for the determination of a site and extent of acute myocardial infarction

    International Nuclear Information System (INIS)

    Results of plane santigraphy of myocardium (PSM) and single-photon emission computerized tomography (SPECT) of heart with 99mTc-pyrophosphate are compared to study diagnostic value of the latter in the determination of focal changes in myocardium, ascertaining localization and propagation of the disease focus in patients with myocardial infarction (MI). 40 patients have been examined. Localization and propagation of the process were determined by the inclusion of RP in necrosis focus at a certain number of sections. It is ascertained that SPECT permits to determine IM localization and its propagation more precisely than PSM. For IM of front localization (according to SPECT data) sections in all orthogonal planes proved to be informative, for IM of lower localization-saggital and frontal ones, and for the lateral IM - axial and frontal sections

  18. Advanced quantitative 201-Tl gated SPECT (QGS-A) images for the assessment of left ventricular function and volumes. Comparison with two-dimensional echocardiography

    International Nuclear Information System (INIS)

    The aim of this study was to assess the clinical significance and validity of the advanced quantitative 201-Tl and 99m-Tc gated SPECT (QGS-A) methods. We studied 79 patients (48 men, 31 women; mean age 70±14 yr) with cardiomyopathy (n=4) and ischemic (n=57) or congestive heart disease (n=18). All subjects were investigated as to the correlation between values with QGS-A and UCG. Either 201-Tl (n=51) or 99m-Tc (n=28) gated SPECT was performed at rest (n=48) or stress (n=31) stage followed by UCG within one month. Gated SPECT data, including EDV, ESV, and LVEF, were quantified by using an automatic algorithm as QGS-A, whereas UCG data (EDV, ESV, and LVEF) were determined by the standard technique. A significant correlation was found between 201-Tl or 99m-Tc QGS-A and UCG with respect to EDV, ESV, and LVEF (201-Tl: r=0.761, 0.882, 0.819; 99m-Tc: r=0.515, 0.765, 0.695, respectively, all p values <0.01), regardless of the use of rest images. The mean values of EDV, ESV, and LVEF calculated by QGS-A were significantly lower than those of UCG (all p values <0.01). LV volumes and LVEF calculated by both 201-Tl and 99m-Tc QGS-A were significantly correlated with those obtained by UCG. These findings support the clinical significance and validity of 201-Tl and 99m-Tc QGS-A for simultaneously assessing both LV function and myocardial perfusion imaging. (author)

  19. 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?

    OpenAIRE

    Hamid Javadi; Ali Mahmoud-Pashazadeh; Abdollatif Amini

    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...

  20. Utility of QGS for 201Tl electrocardiogram-gated SPECT in cardiac function evaluations

    International Nuclear Information System (INIS)

    QGS (quantitative gated SPECT) was applied to 201Tl SPECT, whose images are inferior to those of Tc SPECT, and its utility was evaluated. More specifically, the cardiac function index was calculated by QGS, and local wall motion was evaluated visually. Accuracy was assessed by comparison with left ventriculography. The subjects were 29 patients (21 males, 8 females; 6 with myocardial infarction, 18 with stenocardia, 2 with pericardial disease, 3 with other heart diseases) who had undergone myocardial scintigraphy and left ventriculography between February and May, 2000. 201Tl (74 or 111 MBq) was administered to all patients. The resting image was obtained 10 minutes later, and the delayed image during loading was obtained 4 hours later. The conditions for acquiring the images were as follows. Two detectors were arranged at a 90-degree angle in the form of an L. The 180 degrees from 45 degrees right anterior oblique (RAO) to 45 degrees left posterior oblique (LPO) were divided into 30 sections at 6-degree intervals, and the image in each section was acquired for 60 seconds. The matrix was 64 x 64. As a cardiac function index, the left ventricular ejection function (LVEF) obtained by electrocardiogram-gated SPECT (QGS-EF) at the rest (14 cases) and the QGS-EF on the delayed images (15 cases) were compared with the LVEF determined by left ventriculography (LVG-EF). There was an excellent positive correlation between the data obtained by two methods, with a correlation coefficient of r=0.93 (y=1.04x-0.04). Most of the difference between the values fell within two standard deviations, and the error was in the clinically allowable range. There was no significant difference between the correlation coefficient at rest and during loading or between the cases that showed an obvious defect on the image and those that did not. The local wall motion of the left ventricle was visually evaluated in five stages in two directions (RAO, 30 degrees, and LAO, 60 degrees). The motion scores in the QGS image and the LVG image agreed in 124 (67.4%) of 184 areas. A difference of one level in the score was shown in 42 areas (22.8%) and a difference of 2 or more levels in the score in 18 areas (9.8%). The results demonstrated that evaluation of myocardial blood-flow functions by 201Tl electrocardiogram gated SPECT is possible. (K.H.)

  1. Clinical significance of reverse redistribution on thallium-201 single-photon emission computed tomography in patients with acute myocardial infarction

    International Nuclear Information System (INIS)

    To determine the clinical significance of reverse redistribution (RR), resting thallium-201 myocardial single-photon emission computed tomography was performed once or twice in 80 patients in subacute phase (1 week to 2 months) of myocardial infarction. Thirty eight patients demonstrated RR on at least one study (group RR) and 32 a fixed defect only (group FD). Group RR had significantly smaller defects than group FD. Standardizing the relation of the severity of wall motion abnormality of left ventricle on echocardiogram with that of perfusion defect, in group RR wall motion abnormality in the acute and subacute phase reflected the defect of delayed image, while that in chronic phase, which was thought to reflect the viability of myocardium in the infarct region, reflected the defect of initial image. In serial thallium-201 studies, only the defect of delayed image of group RR improved on the second study, while the defect of initial image of group RR and defect of group FD did not improve. Wall motion of group RR improved with the disappearance of RR, and when RR remained, wall motion did not improve so much. We concluded that RR was thought to be demonstrated in viable myocardium with severe wall motion abnormality. (author)

  2. The standardization of 201Tl by liquid scintillation coincidence counting

    International Nuclear Information System (INIS)

    A high quality solution of 201Tl produced at the National Accelerator Centre in South Africa has been standardized by liquid scintillation coincidence counting. An analysis of the counting efficiency relating to the standardization is described. An ampoule containing a sample of the solution was sent to the Bureau International des Poids et Mesures for comparative measurement. The registration table and a plot based thereon are presented. 12 refs., 6 figs., 3 tabs

  3. Cardiofocal collimators for gated single-photon emission tomographic myocardial perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Everaert, H.; Vanhove, C.; Franken, P.R. [Division of Nuclear Medicine, University Hospital, Free University of Brussels (AZ VUB), Brussels (Belgium); Hamill, J.J. [Nuclear Medicine Group, Siemens Medical Systems Inc., Hoffman Estates, Ill. (United States)

    1998-01-01

    In this article the feasibility and accuracy of gated SPET myocardial perfusion imaging using a triple-head camera equipped with CFC, is evaluated. Twenty patients with a history of myocardial infarction were studied. SPET myocardial perfusion images, gated in eight time bins, were acquired in a random sequence with a PHC and a CFC for each patient. Imaging was started 60 min after the injection of 925 MBq of technetium-99m tetrofosmin at rest. The extent (EXT) and severity (SEV) of perfusion defects were quantified on polar maps using the non-gated data. Left ventricular volumes [end-diastolic volume (EDV), end-systolic volume (ESV)] and ejection fraction (LVEF) were calculated from gated data using the Cedars-Sinai program. In 17 of 20 patients the complete left ventricle was positioned within the useful field of view of the CFC. The results in respect of perfusion, volumes and ejection fraction were almost identical to those obtained with the PHC. The mean difference{+-}SD between the CFC and the PHC was -2.30{+-}7.16 (% of LV area) for EXT, -0.48{+-}2.90 for SEV (arbitrary units), -1,50{+-}5.25 (ml) for EDV and 0.53{+-}4.10 (%) for LVEF. The largest differences in EXT and LV volumes were observed in patients in whom a part of the LV was not positioned within the useful field of view. We conclude that, for the mfjority of patients, identical information with regard to both perfusion and function can be derived from gated SPET myocardial perfusion studies obtained with PHCs or with CFCs. Because of the greater sensitivity, however, a much shorter acquisition time is required with CFCs. (orig.) With 5 figs., 2 tabs., 5 refs.

  4. Cardiofocal collimators for gated single-photon emission tomographic myocardial perfusion imaging

    International Nuclear Information System (INIS)

    In this article the feasibility and accuracy of gated SPET myocardial perfusion imaging using a triple-head camera equipped with CFC, is evaluated. Twenty patients with a history of myocardial infarction were studied. SPET myocardial perfusion images, gated in eight time bins, were acquired in a random sequence with a PHC and a CFC for each patient. Imaging was started 60 min after the injection of 925 MBq of technetium-99m tetrofosmin at rest. The extent (EXT) and severity (SEV) of perfusion defects were quantified on polar maps using the non-gated data. Left ventricular volumes [end-diastolic volume (EDV), end-systolic volume (ESV)] and ejection fraction (LVEF) were calculated from gated data using the Cedars-Sinai program. In 17 of 20 patients the complete left ventricle was positioned within the useful field of view of the CFC. The results in respect of perfusion, volumes and ejection fraction were almost identical to those obtained with the PHC. The mean difference±SD between the CFC and the PHC was -2.30±7.16 (% of LV area) for EXT, -0.48±2.90 for SEV (arbitrary units), -1,50±5.25 (ml) for EDV and 0.53±4.10 (%) for LVEF. The largest differences in EXT and LV volumes were observed in patients in whom a part of the LV was not positioned within the useful field of view. We conclude that, for the mfjority of patients, identical information with regard to both perfusion and function can be derived from gated SPET myocardial perfusion studies obtained with PHCs or with CFCs. Because of the greater sensitivity, however, a much shorter acquisition time is required with CFCs. (orig.)

  5. A new dynamic myocardial phantom for the assessment of left ventricular function by gated single-photon emission tomography

    International Nuclear Information System (INIS)

    Gated myocardial perfusion single-photon emission tomography (SPET) has been used for the measurement of left ventricular (LV) function and validated by means of comparison with other imaging modalities. We have designed a new dynamic myocardial phantom in order to validate the LV function as assessed by the use of gated myocardial perfusion SPET. The phantom consists of two half-ellipsoids (an endocardial surface and an epicardial surface) and a thorax. The myocardial space is filled with a radioactive solution. The endocardial surface moves continuously towards and away from the epicardial surface in the longitudinal axis to vary the LV volume [143 ml at end-diastole (ED), 107 ml at end-systole (ES)] and thickness (apex 8 mm at ED and 26 mm at ES, midplane 8 mm). The mean values of wall motion (WM) for the apical midplane region and the basal midplane region were 5 mm and 2 mm, respectively. Gated myocardial SPET was performed during 8 and 16 intervals. These projection data sets were processed using a Butterworth filter with an order of 5 and a critical frequency of 0.34 cycles/cm. LV function was calculated using the quantitative gated SPET (QGS) algorithm. The LV function values estimated by gated SPET during 16 intervals [22% for ejection fraction (EF), 3.7 mm for WM of the apical midplane, 1.7 mm for WM of the basal midplane] closely resembled actual LV functions [25% for EF, 5 mm for WM of the apical midplane, 2 mm for WM of the basal midplane]. However, the estimated values during 8 intervals were smaller than those during 16 intervals (19% for EF, 3.3 mm for WM of the apical-midplane, 1.1 mm for WM of the basal-midplane). The estimated LV volumes closely correlated with the actual volumes (r=0.99 for 16 intervals, r=0.95 for 8 intervals). Utilizing this phantom, LV function estimated using gated myocardial SPET can be compared with actual values. (orig.)

  6. A new dynamic myocardial phantom for the assessment of left ventricular function by gated single-photon emission tomography.

    Science.gov (United States)

    Kubo, N; Morita, K; Katoh, C; Shiga, T; Konno, M; Tsukamoto, E; Morita, Y; Tamaki, N

    2000-10-01

    Gated myocardial perfusion single-photon emission tomography (SPET) has been used for the measurement of left ventricular (LV) function and validated by means of comparison with other imaging modalities. We have designed a new dynamic myocardial phantom in order to validate the LV function as assessed by the use of gated myocardial perfusion SPET. The phantom consists of two half-ellipsoids (an endocardial surface and an epicardial surface) and a thorax. The myocardial space is filled with a radioactive solution. The endocardial surface moves continuously towards and away from the epicardial surface in the longitudinal axis to vary the LV volume [143 ml at end-diastole (ED), 107 ml at end-systole (ES)] and thickness (apex 8 mm at ED and 26 mm at ES, midplane 8 mm). The mean values of wall motion (WM) for the apical midplane region and the basal midplane region were 5 mm and 2 mm, respectively. Gated myocardial SPET was performed during 8 and 16 intervals. These projection data sets were processed using a Butterworth filter with an order of 5 and a critical frequency of 0.34 cycles/cm. LV function was calculated using the quantitative gated SPET (QGS) algorithm. The LV function values estimated by gated SPET during 16 intervals [22% for ejection fraction (EF), 3.7 mm for WM of the apical midplane, 1.7 mm for WM of the basal midplane] closely resembled actual LV functions [25% for EF, 5 mm for WM of the apical midplane, 2 mm for WM of the basal midplane]. However, the estimated values during 8 intervals were smaller than those during 16 intervals (19% for EF, 3.3 mm for WM of the apical-midplane, 1.1 mm for WM of the basal-midplane). The estimated LV volumes closely correlated with the actual volumes (r=0.99 for 16 intervals, r=0.95 for 8 intervals). Utilizing this phantom, LV function estimated using gated myocardial SPET can be compared with actual values. PMID:11083542

  7. Computerized study with 201Tl of the gold thyroid node

    International Nuclear Information System (INIS)

    Because of its physical and potassium-metabolic characteristics 201Tl is more suitable than 131Cs for radioisotopic studies of the cold thyroid nodule, with the further diagnostic possibility of quantitatively assessing intranodular behaviour for a specific differentiation among different kinds of neoformations. Using a gamma-camera on line with a computer data processing device, sequential scintiscans were recorded for the first 20-30 min after i.v. administration of 15-20 ?Ci/kg of radiothallium; delayed sequences were taken at 40-60 min if intranodular uptake appeared. A quantitative appraisal was made of the differential 201Tl uptake-ratio between nodule and healthy thyroid tissue (density-index) and the multiparameter analysis of thyroid time/activity curves generated on the relative regions of interest (ROIs). This computerized study, in 120 out of 293 patients submitted to this radiothallium test, has shown a) diagnostic agreement between clinical-histological and radioisotopic findings in 76 out of 79 colloid-cystic or degenerative neoformations, in all 16 malignant and in 23 out of 25 hyperplastic benign nodules; b) significant statistical difference of the density-index in solid versus cystic but not between benign and malignant nodules; c) different 201Tl kinetics behaviour in different kinds of solid thyroid lesions with a satisfactory statistical difference of the radiothallium nodular dissappearance-index. (orig.)

  8. The role of thallium-201 single photon emission tomography in the investigation and characterisation of brain tumours in man and their response to treatment

    International Nuclear Information System (INIS)

    The aim of this study was to characterise brain tumour type and treatment response in relation to the uptake of thallium-201. 201Tl single photon emission tomography (SPET) was performed in 58 patients with brain tumours. Fifty-six patients were utilised for the statistical comparison of the early and delayed 201Tl indices expressed as the ratio of tumour to contralateral cerebral hemisphere uptake. The retention index of 201Tl in the tumour tissue calculated from the early and delayed scans was also analysed. Furthermore, in 56 patients with 58 brain tumours, a comparison was made of the diagnostic value of high 201Tl uptake and gadolinium diethylene triamine penta-acetic acid (Gd-DTPA) enhancement on MRI scans. Although high 201Tl uptake was observed in viable malignant gliomas, brain metastases, meningiomas and malignant teratoma, the viable malignant gliomas could not be differentiated from brain metastases and extracerebral tumours by means of 201Tl indices. 201Tl SPET failed to diagnose a viable ring-enhanced tumour with a thin rim and small tumours of less than 1.5 cm in diameter visualised by Gd-DTPA-enhanced MRI. In spite of this, 201Tl SPET appears to be effective for determination of the malignant viability of tumours. (orig.)

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

    International Nuclear Information System (INIS)

    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.)

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

    International Nuclear Information System (INIS)

    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

  11. Single photon emission computed tomography of technetium-99m tetrofosmin myocardial perfusion imaging in patients with systemic lupus erythematosus-A preliminary report

    International Nuclear Information System (INIS)

    The purpose of this study was to evaluate the utility of single-photon emission computed tomography (SPECT) of technetium-99m tetrofosmin (Tc-99m TF) myocardial perfusion imaging to detect myocardial involvement in patients with systemic lupus erythematosus (SLE). Three groups of subjects-group 1: 25 SLE female patients with non-specific cardiac symptoms and signs, group 2: 25 female SLE patients without any cardiac symptoms and signs, and group 3: 25 female healthy controls-were evaluated by comparing rest and dipyridamole-stress Tc-99m TF myocardial perfusion SPECT. Tc-99m TF myocardial perfusion SPECT revealed perfusion defects in 88% and 40% of the cases in groups 1 and 2, respectively. However, no cases in group 3 demonstrated myocardial perfusion defects. Tc-99m TF myocardial perfusion SPECT is a useful noninvasive imaging modality to detect cardiac involvement in SLE patients with or without cardiac symptoms and signs. (author)

  12. Single photon emission computed tomography of technetium-99m tetrofosmin myocardial perfusion imaging in patients with systemic lupus erythematosus-A preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Jen-Jhy; Hsu, Hsiu-Bao; Sun, Shung-Shung; Kao, Chia-Hung [China Medical Coll., Taichung, Taiwan (China). Hospital; Wang, Jhi-Joung [Chi-Mei Medical Center, Tainan, Taiwan (China); Ho, Shung-Tai [National Defense Medical Center, Taipei, Taiwan (China). School of Medicine

    2003-01-01

    The purpose of this study was to evaluate the utility of single-photon emission computed tomography (SPECT) of technetium-99m tetrofosmin (Tc-99m TF) myocardial perfusion imaging to detect myocardial involvement in patients with systemic lupus erythematosus (SLE). Three groups of subjects-group 1: 25 SLE female patients with non-specific cardiac symptoms and signs, group 2: 25 female SLE patients without any cardiac symptoms and signs, and group 3: 25 female healthy controls-were evaluated by comparing rest and dipyridamole-stress Tc-99m TF myocardial perfusion SPECT. Tc-99m TF myocardial perfusion SPECT revealed perfusion defects in 88% and 40% of the cases in groups 1 and 2, respectively. However, no cases in group 3 demonstrated myocardial perfusion defects. Tc-99m TF myocardial perfusion SPECT is a useful noninvasive imaging modality to detect cardiac involvement in SLE patients with or without cardiac symptoms and signs. (author)

  13. Impact of Co-morbidity on the Risk of First-Time Myocardial Infarction, Stroke, or Death After Single-Photon Emission Computed Tomography Myocardial Perfusion Imaging

    DEFF Research Database (Denmark)

    Schelde, Astrid Blicher; Schmidt, Morten

    2014-01-01

    The impact of co-morbidity on the cardiovascular risk after single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI) remains unclear. We examined the association between a normal versus abnormal SPECT MPI scan on 10-year risk of myocardial infarction, stroke, and all-cause death, overall and according to co-morbidity level. We identified all patients without previous myocardial infarction or cerebrovascular disease, who had an SPECT MPI performed at Aarhus University Hospital Skejby during 1999 to 2011. We categorized the SPECT MPI scan as normal (no defects) or abnormal (reversible and/or fixed defects). Using nationwide medical registries, we obtained information on co-morbidity level (using Charlson co-morbidity index) and outcomes. We used Cox regression to compute hazard ratios with 95% confidence intervals (CIs), adjusting for gender, age, and co-morbidity level. Among 7,040 patients, 4,962 (70%) had normal scans and 2,078 (30%) abnormal scans. Patients with a normal versus abnormal scan had a 10-year risk of 5.7% versus 10.9% for myocardial infarction, 6.0% versus 7.8% for stroke, and 16.5% versus 29.0% for all-cause death. After adjustment, an abnormal scan was associated with increased risk of myocardial infarction (adjusted hazard ratio 1.73, 95% CI 1.37 to 2.18) and all-cause death (1.42, 95% CI 1.23 to 1.65) but not stroke (1.12, 95% CI 0.86 to 1.45). Co-morbidity level did not affect substantially the association between the scan result and the outcomes. In conclusion, independently of co-morbidity level, an abnormal SPECT MPI scan was associated with an increased 10-year risk of myocardial infarction and all-cause death but not stroke.

  14. 123I-HDA and 201Tl-chloride: A comparative study in coronary artery disease

    International Nuclear Information System (INIS)

    By means of the 7-pinhole collimator technique 21 patients with CAD and 7 patients with acute myocardial infarction were examined scintigraphically both with 201-Tl and 123-I-Heptadecanoic acid. The results obtained with both tomographic techniques were concordant. MI's and scars are displayed in the same fashion as regions of diminished or absent accumulation of radioactivity. Some of the patients with acute MI present the defect in the fatty acid scintigram as cold-warm-lesion, i.e. diminished tracer accumulation in the early image and fill-in in the late image (so-called d-type-lesion). These lesions were not observed in cases of stress induced ischemia. Therefore it is not possible to sustain hypothesis that these lesions correlate with borderline perfused myocardium. (Author)

  15. The observation of 201TlCl scintigraphy in thyroid follicular adenoma

    International Nuclear Information System (INIS)

    201TlCl scintigraphy in 19 cases of thyroid follicular nodules after 99mTc scintigraphy visualized a thyroid cold nodules. The results showed that 201TlCl uptake in cold nodules of 6 cases still remained deficient. 201TlCl uptake of 10 nodules was the same as normal thyroid tissue, whereas that of 3 nodules higher than normal thyroid tissue. The overall positivity was 13/19

  16. Effect of scatter correction on quantification of myocardial SPECT and application to dual-energy acquisition using triple-energy window method

    International Nuclear Information System (INIS)

    Triple-energy window (TEW) method is a simple and practical approach for correcting Compton scatter in single-photon emission tracer studies. The fraction of scatter correction, with a point source or 30 ml-syringe placed under the camera, was measured by the TEW method. The scatter fraction was 55% for 201Tl, 29% for 99mTc and 57% for 123I. Composite energy spectra were generated and separated by the TEW method. Combination of 99mTc and 201Tl was well separated, and 201Tl and 123I were separated within an error of 10%; whereas asymmetric photopeak energy window was necessary for separating 123I and 99mTc. By applying this method to myocardial SPECT study, the effect of scatter elimination was investigated in each myocardial wall by polar map and profile curve analysis. The effect of scatter was higher in the septum and the inferior wall. The count ratio relative to the anterior wall including scatter was 9% higher in 123I, 7-8% higher in 99mTc and 6% higher in 201Tl. Apparent count loss after scatter correction was 30% for 123I, 13% for 99mTc and 38% for 201Tl. Image contrast, as defined myocardium-to-left ventricular cavity count ratio, improved by scatter correction. Since the influence of Compton scatter was significant in cardiac planar and SPECT studies; the degree of scatter fraction should be kept in mind both in quantification and visual interpretation. (author)

  17. Utility of 123I-?-methyl iodophenyl pentadecanoic acid (BMIPP) myocardial scintigraphy in the diagnosis of the cardiac involvement in sarcoidosis

    International Nuclear Information System (INIS)

    We evaluated the utility of myocardial scintigraphy using 123I-?-methyl iodophenyl pentadecanoic acid (123I-BMIPP) in the diagnosis of cardiac sarcoidosis. Myocardial single photon emission computed tomographies (SPECT) with 123I-BMIPP and 201Tl were performed in 26 patients with sarcoidosis. Each of basal and mid left ventricular levels of the short axis image of SPECT was divided into 6 segments, and the apical lesion obtained from the long axis image of SPECT was added making 13 segments in all. Then we got the defect score including four steps from normal uptake to defect. We examined the correlation between the defect score of 123I-BMIPP and that of 201Tl. Significant correlations were observed between defect score of 123I-BMIPP and 201Tl. The reduction of uptake in myocardial SPECT with 123I-BMIPP reflects cardiac involvement in the patients with sarcoidosis. The results suggest the usefulness of the myocardial scintigraphy with 123I-BMIPP in the diagnosis of cardiac involvement in sarcoidosis. (author)

  18. 201Tl scintigraphy in postoperative detection of thyroid cancer: a comparative study with 131I

    International Nuclear Information System (INIS)

    201Tl scintigraphy was performed to visualize malignant lesions postoperatively in 28 patients with thyroid cancer. The results were compared with those of 131I and/or /sup 99m/Tc pertechnetate scintigraphy. Of eight patients who had malignant lesions and no normal thyroid tissue, 201Tl concentration was observed in seven, while 131I concentration was observed in only three. All of four patients who had malignant lesions and did have remaining normal thyroid tissue showed concentrations of 201Tl. 201Tl scintigraphy can be performed without any preparation and may be useful in depicting residual and recurrent lesions regardless of the presence of normal thyroid tissue

  19. Comparative study of myocardial perfusion imaging by TL-201 single-photon ECT and N-13 ammonia positron CT

    International Nuclear Information System (INIS)

    Thallium (Tl) single-photon emission CT (SPECT) has been available for three-dimensional evaluation of myocardial perfusion. To assess the value and limitation of Tl SPECT, the images were compared with N-13 ammonia positron CT(PCT) in phantom and clinical studies. SPECT was performed by gamma camera rotation over 1800 after Tl 2 mCi injection. PCT was performed using 4 detector ring whole-body PCT device after N-13 ammonia 20 mCi injection. Acquisition time was 16 min for SPECT and 20 min (transmission) plus 10 min (emission) for PCT. No attenuation correction was done in SPECT, while in PCT it was accurately performed from the transmission data. Collected counts in a single slice were 100-180K by SPECT and 5-12M by PCT. The spatial resolution was about 16 mm for SPECT and 8 mm for PCT in FWHM. Because of better resolution and higher count statistics, PCT delineated fine cardiac structures, such as papillary muscles and apical thinning, while the myocardium looked thicker in SPECT due to poorer resolution. Regional distribution was comparatively evaluated by circumferential profile methods in the same plane in 5 normal cases. As compared to PCT, Tl distribution was less in the septal and posterior regions, and more in the lateral region due to photon attenuation. The authors conclude that Tl SPECT provides poorer images due to inadequate count density with poor resolution, as compared to PCT. It has severe limitation for quantitative evaluation of myocardial perfusion. However, one of the advantages of SPECT is that cardiac short-axis and long-axis sections can easily be reorganized

  20. The dobutamine stress Tl-201 myocardial single photon emission computed tomography for coronary artery stenosis caused by Kawasaki disease

    International Nuclear Information System (INIS)

    Noninvasive cardiac imaging with pharmacologic stress Tl-201 single photon emission computed tomography (SPECT) as an alternative to exercise test is now getting popular for patients with Kawasaki disease. Dobutamine infusion produces hemodynamic change which is quite similar to exercise induced hemodynamic change. Material consisted of 17 patients (13 males, 4 females) with coronary occlusion or significant coronary stenosis (?75% diameter stenosis) caused by Kawasaki disease. After step-wise infusion of dobutamine up to 40 ?g/kg/min., quantitative analysis of Tl-201 SPECT was obtained. No patient had a symptomatic arrhythmia or severely stress-induced ischemia. The sensitivity and specificity of dobutamine induced perfusion defects were 65% (11 to 17) and 92% (1 of 13) respectively. The sensitivity was 87% (7 of 8) in patients with the left coronary artery lesions and 46% (6 of 13) in patients with the right coronary artery lesions. We conclude that a quantitative analysis of Tl-201 SPECT after step-wise infusion of dobutamine is a safe and clinically useful method for detection of stress-induced myocardial ischemia in coronary artery stenosis caused by Kawasaki disease. (author)

  1. Myocardial sestamibi single-photon emission tomography: variations in reference values with gender, age and rest versus stress?

    International Nuclear Information System (INIS)

    Reference data files support the evaluation of myocardial perfusion single-photon emission tomography (SPET). The aim of this study was to create a large reference data base for technetium-99m sestamibi SPET, age and gender matched to the general patient population. One hundred and twenty-eight healthy volunteers (76 males and 52 females) with a likelihood of coronary artery disease of less than 5% underwent rest and maximal exercise 99mTc-sestamibi SPET with a 2-day protocol and 180 elliptical rotation. The normalized activity values of 99mTc-sestamibi in the inferior wall differed significantly between men and women. Age variations were found for men in the anterior wall. Normalized activity values in all four walls were strikingly similar during rest and stress. Our results suggest that the use of reference files in 99mTc-sestamibi SPET requires a gender- and, for males, possibly an age-matched reference population. Different reference files at rest and during stress might not be necessary. (orig.). With 3 figs., 3 tabs

  2. Myocardial uptake of thallium-201 diethyldithiocarbamate (Tl-201-DDC) in cultured heart cells and in humans

    International Nuclear Information System (INIS)

    We assessed the feasibility of SPECT imaging with 201Tl-diethyldithiocarbamate (201Tl-DDC), a new cerebral blood flow tracer with little redistribution, expecting to observe less extensive redistribution than with 201Tl-chloride. Myocardial sections were obtained in three patients presenting with documented coronary artery disease and injected at peak exercise with 100 MBq 201Tl-DDC. In two patients there was a clear redistribution phenomenon at four h after injection. In cultured myocardial cells of newborn rats, the uptake and washout of 201Tl-chloride and 201Tl-DDC were compared. The 201Tl-DDC uptake was lower than 201Tl-chloride (transmembrane gradients were respectively 89±10 and 4.1±0.2, mean±sem, n=14, P201Tl-chloride in the cells was 4% vs 19% for 201Tl-DDC. It is concluded that although myocardial imaging is feasible with 201Tl-DDC, this agent redistributes significantly with time. (orig.)

  3. Transverse CAT of the myocardium with 201 Tl

    International Nuclear Information System (INIS)

    A new computerized axial tomographic (CAT) scanner (J and P Tomoscanner) which enables the transverse section viewing of any organ labelled by one of the monophotonic gamma-ray emitting tracers commonly used in Nuclear Medicine, has been recently commercialized. Its abilities in visualing the 201 Tl labelled myocardium are evaluated with normal hearts and patients with documented infarctions. Positive results have been obtained, allowing an interesting approach to the estimation of the anatomical extent of necrosis. (orig.) 891 MG/orig. 892 MBE

  4. Early effects of gamma knife radiosurgery on brain metastases. Assessment by 201TlCl SPECT and 99mTc-DTPA-human serum albumin SPECT

    International Nuclear Information System (INIS)

    Thallium-201 chloride (201TlCl) single photon emission computed tomography (SPECT) was used to determine tumor viability, and the early and delayed images of technetium-99m-diethylenetriaminepentaacetic acid-human serum albumin (99mTc-HSA-D) SPECT were used to assess tumor vascularity and permeability, respectively, in 17 patients with 18 brain metastases. SPECT was performed before, 1 week after, and 1 month after radiosurgery. The ratios of 201Tl and 99mTc-HSA-D uptake in a tumor were expressed as a ratio to uptake in the corresponding normal contralateral areas (uptake index). Magnetic resonance imaging with gadolinium was used to determine tumor volume. 201Tl index decreased significantly 1 week (p99mTc-HSA-D indices of early and delayed images obtained at 1 week after radiosurgery were not significantly different from the pretreatment values. However, both were significantly low (p<0.05) 1 month after radiosurgery. No change in tumor volume was detected 1 week following radiosurgery, but there wag a significant decrease (p<0.005) after 1 month. The reduction in tumor viability that occurs before the appearance of evidence of tumor shrinkage represents the early effect of radiosurgery on brain metastases. Reduction in tumor size, vascularity, and permeability occur subsequently. (author)

  5. Clinical evaluation of 99mTc-CPI myocardial perfusion single photon emission computerized tomography in the diagnosis of coronary heart disease

    International Nuclear Information System (INIS)

    Two normal subjects, 5 patients with old myocardial infarction (OMI) and 4 patients with angina pectoris were examined by rest single photon emission computerized tomography revealed that the right ventricular was not imaged, the left ventricular was well exposed in the normal subjects. All the 9 patients had defects in the left ventricle. comparison of SPECT with 99mTc-CPI with selective coronary arteriography (SCA), echocardiography (UCG), dynamic electrocardiography (DCG) and electrocardiographic (ECG)-exercise test in the diagnosis of myocardial ischemia or necrosis has demonstrated the former to be more significantly sensitive than the latter four. Good agreement between SPECT and SCA has been confirmed

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

    International Nuclear Information System (INIS)

    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 (?PSI). 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

  7. Dipyridamole loaded 201Tl muscle scintigraphy in the diagnosis of obliterative peripheral arterial disease

    International Nuclear Information System (INIS)

    In peripheral obliterative arterial disease the administration of 201Tl decreases the isotope activity in the muscle of thigh and calf. On dipyridamole (Persantin) application the isotope accumulation further diminishes in the affected muscles. There was a correlation between the data of 201Tl muscle scintigraphy and the transfemoral arteriography. (author) 20 refs.; 2 figs

  8. Fundamental studies of myocardial defect size quantification using positron emission tomography and single photon emission computed tomography

    International Nuclear Information System (INIS)

    In Flurine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) acquisition, a transmission scan is usually performed before the PET tracer injection (cold transmission method), followed by a subsequent emission scan. However, this procedure is time consuming. An alternative approach, in which the transmission scan is performed after the emission scan (hot transmission method), would significantly reduce the time required for data acquisition. Recently, three-dimensional PET acquisition (3D PET) has become available. The counting sensitivity is much higher in 3D PET than in conventional two-dimensional PET (2D PET), resulting in a shorter acquisition time and reduced radiation exposure for the patient. On the other hand, 18F-FDG imaging using single photon emission computed tomography (SPECT), a more widely available method than PET, has emerged as an alternative to PET. The purpose of this study was to investigate the accuracy of measurement of myocardial defect sizes by these new techniques, using a chest phantom. Acquisitions were performed using an elliptical cylinder chest phantom. Plastic inserts, ranging in size from 2-60% of the myocardium (n=12), were used as simulated models of transmural myocardial infarction. Fluorine-18 was given into each part of the phantom. PET imaging with cold and hot transmission methods, 3D PET, and SPECT imaging were performed with different acquisition times and different radioisotope concentrations. All PET and SPECT data were analyzed using a semiquantitative polar map approach. Defect sizes were quantified using various cutoff thresholds, and were expressed as a percentage of the left ventricular myocardium. The PET and SPECT measurements were compared with the true defect sizes. Among the various cutoff levels tested, the mean absolute difference between the measured and true defect sizes was minimal at 50% of peak activity for both PET and SPECT. The PET measurements with the hot transmission method showed an excellent correlation with true defect sizes, and the mean absolute error of measurements were similar between the hot and cold transmission methods. In particular, the mean absolute error of 3D PET measurements was smaller than 2D PET for a short acquisition time (10 seconds) and low radioisotope concentrations (25 kBq/ml and 50 kBq/ml). Finally, the SPECT measurements were similar to the PET measurements and closely correlated with the true defect sizes. In conclusion, cardiac PET imaging with these new acquisition techniques is feasible, and 3D PET is more useful than 2D PET in respect of the short acquisition times and low radioisotope concentrations. Furthermore, 18F-FDG SPECT imaging may also be useful to delineate viable myocardium from scarred myocardium in a manner similar to PET. (author)

  9. Detection of impaired fatty acid metabolism in right ventricular hypertrophy. Assessment by I-123 ?-methyl iodophenyl pentadecanoic acid (BMIPP) myocardial single-photon emission computed tomography

    International Nuclear Information System (INIS)

    The subjects consisted of 6 patients with chronic obstructive pulmonary disease, 4 with primary pulmonary hypertension, 2 each with refractory pulmonary tuberculosis, tricuspid insufficiency, pulmonary embolism, 1 each with atrial septal defect, ventricular septal defect (Eisenmenger complex), Ebstein anomaly, and endocardial defect, and 7 healthy controls. SPECT imaging with Tl-201 (Tl) and I-123 BMIPP, and Tc-99m RBC first pass and gated blood pool scintigraphy were performed. Based on Tl planar images, the subjects were classified into 3 groups: 7 patients with no RV visualization (Group A), 11 with moderate RV visualization (Group B) and 9 with marked RV visualization (Group C). As a semi-quantitative evaluation by a myocardial SPECT, 3 regions in 3 representative short axial images were divided into 9 segments, each of which was graded from 0 to +3, and their sum was calculated as the RV score. The right ventricular ejection fraction (RVEF and the left ventricular ejection fraction were obtained by Tc-99m RBC cardiac scintigraphy. The groups with marked visualization of the right ventricle had lower RVEF, and there was a good correlation between the RVEF and the RV score with both a and BMIPP. Although a good correlation was demonstrated between the RV score with Tl and BMIPP in Groups A and B, in Group C, in which there was marked RV Tl visualization, the RV score with BMIPP was significantly smaller than with Tl. These findings suggest that impaired fatty acid metabolism may exist in severely hypertrophic right ventricle due to RV overload. (K.H.)

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

    Directory of Open Access Journals (Sweden)

    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 ?2 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.

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

    International Nuclear Information System (INIS)

    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)

  12. The progress of assessment of myocardial viability by delayed-enhanced magnetic resonance imaging and positron emission tomography and single-photon emission computed tomography

    International Nuclear Information System (INIS)

    Coronary artery disease (CAD)is one of the most common diseases that results in the different degree of myocardial damage. Thus, only viable myocardium in patients can get benefit from the myocardial revascularization. The accurate differentiation of viable and nonviable myocardium is crucial for therapy planning in patients with coronary artery disease and left ventricular dysfunction. Clinically, traditional techniques such as echocardiography, positron emission tomography, and single photon emission computed tomography have established roles. With the recent MRI technical developments allowing for a combined assessment of perfusion and irreversible damage with late enhancement imaging, MRI will now play a major role in the assessment of myocardial viability. Through the technique of delayed-enhancement MRI (DE-MRI), viable and infarcted myocardium can be simultaneously identified in a manner that closely correlates with histopathology findings. (authors)

  13. Transient QT interval prolongation with inverted T waves indicates myocardial salvage on dual radionuclide single-photon emission computed tomography in acute anterior myocardial infarction

    International Nuclear Information System (INIS)

    In patients with acute myocardial infarction (AMI), transient QT interval prolongation with a prominent negative T wave is frequently observed in cases of early spontaneous reperfusion and often indicates a good prognosis. Additionally, in nuclear cardiac imaging, technetium-99m/thallium-201 overlap on dual single-photon emission computed tomography (dual SPECT) in AMI patients indicates the presence of viable myocardium and early recanalization. To elucidate the clinical significance of this transient QT interval prolongation, 34 patients (64±8 years) admitted within 24 h of the onset of anterior AMI were enrolled and classified into 2 groups according to the presence (group A, n=24) or absence (group B, n=10) of scintigraphic overlap on simultaneous dual SPECT imaging. The maximal QTc interval was 0.59±0.06 s in group A and 0.52±0.06 s in group B (p<0.01). The peak creatine kinase was lower in group A (2650±2160 IU/L) than in group B (3490±2060 IU/L). The left ventricular ejection fraction (LVEF) at discharge was 62±11% in group A and 49±14% in group B (p<0.01). The scintigraphic overlap group had a smaller infarct and better LVEF, which suggests that the QT interval prolongation that appears transiently in the acute phase of AMI indicates scintigraphically the presence of salvaged myocardium. (author)

  14. Statistical indices of 201Tl distribution in the myocardium in various diseases

    International Nuclear Information System (INIS)

    A study was made of the diagnostic potentialities of a histogram analysis of scintillation counting distribution on myocardium scans using 201Tl in 9 patients with dilatational cardiomyopathy, 12 patients with coronary heart disease and 6 patients with primary pulmonary hypertension. Scans were recorded 10 min., 4 and 24 h after a single administration of 201Tl at rest in the front-forward, 45 deg left forward oblique and left lateral projections. The author showed a possibility of group distinction by scintillation counting distribution in the heart area on myocardium scans using 201Tl, the distinguishing information being within the interval of 41-80% of maximum intensity in this area

  15. Myocardial imaging with thallium-201 for assessment of regional myocardial perfusion and viability after intracoronary thrombolytic therapy

    International Nuclear Information System (INIS)

    Whereas coronary arteriography demonstrates success of reflow or recanalization after intracoronary thrombolysis, myocardial perfusion imaging with thallium-201 (201Tl) permits assessment of viability of reperfused myocytes. The initial distribution of 201Tl in the myocardium immediately after intravenous injection is the result of both blood flow delivery of the radionuclide to the heart and the extraction fraction for 201Tl. If 201Tl is administered during a period of coronary occlusion, a scintigraphic defect will be observed in the territory of the occluded vessel. If, subsequently, blood flow is restored, as with reperfusion, and cellular kinetics transport of 201Tl returns to normal, myocardial regions initially deprived of 201Tl will demonstrate delayed redistribution and the defect will tend to normalize within several hours. In a sustained coronary occlusion, the defect will persist after 201Tl injection. Specific imaging protocols that have been or can be used to assess thrombolytic therapy are reviewed. If intracoronary streptokinase infusion is associated with a substantial enhancement of perfusion and preservation of cellular integrity in the ischemic zone, delayed 201Tl images obtained several hours after intravenous injection of the radionuclide will demonstrate significantly more 201Tl activity than the images before reflow. Direct intracoronary injections of 201Tl down the infarct vessel have also been used to evaluate the benefit of thrombolytic therapy by the demonstration of increased 201Tl uptake after reperfusion in the ischemic zone. Finally, computer methods for subtracting serial images obtained after two separate intravenous 201Tl injections administered before and after streptokinase infusion might be used to derive a ''functional image'' of the ischemic region that would quantitatively be proportional to the amount of myocardial salvage achieved

  16. Effect of diltiazem on myocardial infarct size estimated by enzyme release, serial thallium-201 single-photon emission computed tomography and radionuclide angiography

    International Nuclear Information System (INIS)

    Diltiazem is a calcium antagonist with demonstrated experimental cardioprotective effects. Its effects on myocardial infarct size were studied in 34 patients admitted within 6 hours after the first symptoms of acute myocardial infarction. These patients were randomized, double-blind to placebo or diltiazem (10-mg intravenous bolus followed by 15 mg/hr intravenous infusion during 72 hours, followed by 4 X 60 mg during 21 days). Myocardial infarct size was assessed by plasma creatine kinase and creatine kinase-MB indexes, perfusion defect scores using single-photon emission computed tomography with thallium-201 and left ventricular ejection fraction measured by radionuclide angiography. Tomographic and angiographic scanning was performed serially before randomization, after 48 hours and 21 days later. Groups were comparable in terms of age, sex, inclusion time and baseline infarct location and size. Results showed no difference in creatine kinase and creatine kinase-MB data between controls and treated patients, a significant decrease in the perfusion defect scores in the diltiazem group (+0.1 +/- 3.0 placebo vs -2.2 +/- 1.9 diltiazem, p less than 0.02) and a better ejection fraction recovery in the diltiazem group (-4.2 +/- 7.4 placebo vs +7.7 +/- 11.2 diltiazem, p less than 0.05). Myocardial infarct size estimates from perfusion defect scores and enzyme data were closely correlated. These preliminary results suggest that diltiazem may reduce ischemic injury in acute myocardial infarction

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

    International Nuclear Information System (INIS)

    Dual single photon emission computed tomography (SPECT) was performed in 31 patients with Duchenne's progressive muscular dystrophy (DMD) using 123I-?-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)

  18. Clinical evaluation of 201Tl-chloride scintigraphy for breast tumors

    International Nuclear Information System (INIS)

    Fifty-two patients with breast tumors were scintigraphed with 201Tl-chloride. Each one was given a histological diagnosis after surgery or excisional biopsy. In 39 cases of primary breast cancer, 27 cases (69.2 %) showed a positive figure by 201Tl-chloride scintigraphy. In five cases of local recurrent breast cancer, four cases (80 %) showed a positive figure. In examining each histological type of primary breast cancer, in 10 cases of papillotubular carcinoma, seven (70 %) were positive with 201Tl-chloride. In 20 patients with medullary tubular carcinoma, 17 cases (85 %) revealed a positive figure. In nine cases of scirrhous carcinoma, only three cases (33.3 %) were positive. Some cases showed an accumulation in the metastatic lymph nodes of the axilla with 201Tl-chloride. In three cases of phyllodes tumor, two cases (66.7 %) were positive. On the other hand, all cases of benign breast tumors showed a negative figure by 201Tl-chloride scintigraphy. As to the uptake ratio of 201Tl-chloride into the breast carcinoma tissue, it was observed that papillotubular carcinoma absorbed 5.8 times as much as normal mammary gland tissue, medullary tubular carcinoma absorbed 4.7 times as much, scirrhous carcinoma absorbed 3.3 times as much as normal mammary gland tissue. In recurrent breast cancer, 201Tl-chloride scintigraphy is a useful procedure in determining the malignant area and in judging the effect of treatment. From the above mentioned results, it was concluded that 201Tl-chloride has specific affinity for malignant breast tumors and it is also very useful tumor-seeking agent to detect the early recurrent breast cancer. (author)

  19. Comparison of 201Tl-SPECT and MRI using Gd-DTPA for glioma

    International Nuclear Information System (INIS)

    201Tl-SPECT was performed in 25 patients with a pathological diagnosis of glioma. The lesion-to-normal (L/N) ratio of the glioblastoma group (n=7) was found to be higher than that of the low-grade glioma group (n=7; Mann-Whitney U-test, p201Tl accumulation in the tumor corresponded to contrast enhancement on MRI in 95% of cases. An insufficient blood-brain barrier was considered to be the primary contributor to 201Tl accumulation. In five cases, there was a discrepancy between the extent of 201Tl accumulation and the Gd-DTPA enhanced area. In these cases, the area of 201Tl accumulation was larger than the area of Gd-DTPA enhancement. This may result from damage to the blood-brain barrier that is not severe enough to be detected with Gd-DTPA or from additional factors other than change in the blood-brain barrier. 201Tl-SPECT is able to demonstrate the extent of glioma more accurately than contrast-enhanced MRI. (author)

  20. Evaluation of thallium-201 washout in patients with ischemic heart disease using ring-type single photon emission CT

    International Nuclear Information System (INIS)

    With the emergence of single photon emission computed tomography (SPECT), thallium-201 (Tl) myocardial scanning has become the important diagnostic procedure of choice for ischemic heart disease; however, clinical and diagnostic aspects still remain unclear. The present study explored kinetics of Tl within the myocardium using ring-type SPECT that allows rapid sequential scanning. Three groups containing five patients with effort angina pectoris (EAP), old myocardial infarction (OMI), or chest pain syndrome (CPS), were scanned during exercise five times at five min intervals after injection of 2.5 - 4.0 mCi of Tl, and subsequently scanned at one, two, and three hr later. Time-activity curves and washout rates in five regions of interest were examined. At 30 min, washout rate was 10 % in the EAP and OMI groups and 0.2 % in the CPS group, showing significant difference between the former two groups and the latter group. This implies that ring-type SPECT may play an important role in elucidating the mechanism of Tl washout and myocardial blood flow, although it has still disadvantages of limited transaxial three scans and inability to correct scattered rays. (Namekawa, K.)

  1. Comparative evaluation of some analyses of stress-redistribution thallium-201 myocardial SPECT for myocardial ischemia

    International Nuclear Information System (INIS)

    Stress-redistribution thallium-201 (201Tl) myocardial single photon emission CT was performed in 55 patients with effort angina and 10 normal subjects. Visual interpretation and some quantitative expressions, which were maximum-count circumferential profile for myocardial distribution of 201Tl, segmental washout rate and each Bull's eye display, were analyzed to evaluate detectability for the territories of stenotic coronary arteries. The sensitivity of the visual method for detection of disease in LAD and RCA was fairly good and the specificity in each of the coronary artery was the highest in every analyses. However, the sensitivity for LCX and detectability in patient with multiple vessel disease were low. Accuracies of circumferential profile analysis and two Bull's eye display were equal or low as compared with visual method. Sensitivity of segmental washout rate was the highest value in every analyses and showed good results even in the patient with LCX lesion or multiple vessel disease. Washout rate score, which was calculated as the area between the washout rate profile curve and normal lower limits in the abnormal region, correlated well with severity of % coronary artery lumen diameter reduction. So we conclude that the visual method in combination with washout rate analysis is useful diagnostic method for detecting and evaluating patient with effort angina. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. Does redistribution in exercise thallium-201 single photon emission computerized tomograms imply ischemia of viable muscle in patients with old myocardial infarction?

    International Nuclear Information System (INIS)

    This study was designed to determine whether redistribution in an area presumed to be infarcted might reflect ischemia of the corresponding residual myocardium on exercise Tl-201 myocardial scintigrams. The subjects were 100 patients with old anteroseptal myocardial infarction who underwent exercise Tl-201 myocardial single photon emission computed tomography. The maximum circumferential profile curve, obtained from the short-axial SPECT images, was quantitatively analyzed for redistribution. The difference in average %Tl uptake of defect areas between initial and delayed (3 hr) images was used as redistribution index (Δ%Tl uptake). Lactate extraction ratio (ΔLER) on atrial pacing was used as ischemic index. The patients were divided into the group in which ischemia was presumed (the ΔLER<0 group) and the group in which it was not presumed (the ΔLER≥0 group). Δ%Tl uptake was 12±7% in the ΔLER<0 group and 3±5% in the ΔLER≥LER group. In the ΔLER≥0 of 60 patients, the highest Δ%Tl uptake was 10%. These findings suggest that redistribution associated with Δ%Tl uptake of more than 10% may strongly reflect ischemia of the residual myocardium in old myocardial infarction. (N.K.)

  4. Sodium bicarbonate-augmented stress thallium myocardial scintigraphy

    International Nuclear Information System (INIS)

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

  5. Sodium bicarbonate-augmented stress thallium myocardial scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-04-01

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

  6. Separation of Tl(I)-Pb(II) by liquid-liquid extraction with diethyldithiocarbamic acid. Isolation of 201Tl

    International Nuclear Information System (INIS)

    The production of 201Tl is described. Natural thallium is irradiated with protons and the induced 201Pb is separated from the target by liquid-liquid extraction with diethyldithiocarbamic acid in chloroform. 201Tl is separated from the mother activity (201Pb) by liquid-liquid extraction with the same reagent. The decontamination of the final product (carrier free 201TlCl) is >=5x106 from the thallium of the target and >5x104 from lead isotopes. (author)

  7. Clinical value of 201Tl lung/heart ratio during exercise in hypertensive patients with coronary artery disease

    International Nuclear Information System (INIS)

    Objective: The purpose of the study was to evaluate the relationship between 201Tl lung/heart ratio during exercise and left ventricular diastolic function and its diagnostic value on severity of coronary artery disease. Methods: One hundred and two patients with documented coronary artery disease were divided into three groups, including no hypertension, hypertension without or with left ventricular hypertrophy groups. Exercise/delay 201Tl myocardial perfusion tomography was performed on all patients included. Lung/heart ratio was defined on the anterior planar image obtained during exercise tomography. Results: The lung/heart ratios during exercise in no hypertension (0.43 +- 0.09, P0.05). The lung/heart ratios of multi-vessel disease subgroup in no hypertension (0.46 +- 0.10 vs 0.40 +- 0.09, P0.05). When lung/heart ratio was≥0.45, the sensitivities for predicting the presence of multi-vessel disease were 82%, 90%, 40% and specificities were 75%, 75%, 45%, respectively, in no hypertension, hypertension without and with hypertrophy groups. In no hypertension (r=0.402, P0.05). In no hypertension (r=-0.413, P<0.01), hypertension without (r=-0.662, P<0.01) and with hypertrophy groups (r=-0.408, P<0.05), lung/heart ratios all showed a significant reverse correlation with correspondent E/A ratios. Conclusions: The exercise lung/heart ratios has a better diagnostic value for multi-vessel disease and left ventricular diastolic function abnormalities of coronary artery disease with or without hypertension, but not for multi-vessel disease in hypertension patients complicated with myocardial hypertrophy

  8. Stress 201Tl-scintigraphy of the myocardium - comparison with veloergometry and selective coronary arteriography in patients with chronic ischeemic heart disease

    International Nuclear Information System (INIS)

    The study has been carried out on 53 patients with complaints of pain with anterior thoracal localization, clinically diagnosed as stable angina pectoris at mild physical efforts; 31 of the patients had a case history of passed myocardial infarction. All patients have been subjected to right-and left-side cardiac catheterization, left ventricular ventriculography and standard selective coronary arteriography 3 to 20 days before or after stress scintigraphy (SS) with 201Tl-chloride. SS is carried out on a static veloergometer by stepwise loading; every 6 min a registration of the 6 thorax ECG-deviations is made and the arterial pressure is mesured. 201Tl-chloride (74 MBk) is injected at the pick of the physical burden. The myocardial perfusion is visualized on 'Nuclear Ohio' gamma camera with a parallel collimator in 3 projections in the course of 6 min for each projection, which allows to evaluate the perfusion of 9 segments of the myocardium. Two hours after the physical loading the myocardial perfusion at rest is studied by the same method. The comparative study shows a considerable advantage of the Tl-SS compared to veloergometry of patients with insignificant haemodynamic coronary stenosis: it allows a precise evaluation of the myocardial perfusion in cases when the appraisal of ECG-changes after a physical loading is difficult. 3 tabs., 5 refs

  9. Study of the predictors and lesion characteristics of ischemic heart disease patients with false negative results in stress myocardial perfusion single-photon emission tomography

    International Nuclear Information System (INIS)

    The predictors and lesion morphology of patients with ischemic heart disease testing false negative results in stress myocardial perfusion single-photon emission computed tomography (SPECT) was investigated. Subjects were 58 consecutive patients who underwent coronary angiography (CAG), even though they showed normal findings in stress myocardial perfusion SPECT. Age, gender, methods of stress, perfusion agent, coronary risk factors, angina symptoms, and electrocardiographic changes were investigated as predictors by multivariate analysis. For lesion morphology, significant stenotic lesions were studied for morphological characteristics and reference diameter (RD), percentage diameter stenosis (%DS), minimum lumen diameter (MLD), and lesion length (LL) were measured. CAG revealed 30 significant stenotic lesions in 18 patients. Logistic regression analysis revealed significant predictors to be age (odds ratio (OR) 1.118, p<0.05), typical anginal pain (OR 21.09, p<0.01), and hypertension (OR 8.336, p<0.05). For lesion morphology, there were only 2 diffuse lesions and the mean RD, %DS, MLD, and LL were 3.03±0.9 mm, 63.1±9.3%, 1.13±0.49 mm, and 13.2±7.0 mm, respectively. Sufficient caution is believed necessary in the interpretation of normal findings of stress myocardial perfusion SPECT when the patient is elderly, complains of typical anginal pain, or has hypertension. In regard to characteristics of lesion morphology, there were hardly any diffuse lesions. (author)

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

    International Nuclear Information System (INIS)

    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: ?end-systolic volume (?ESV), ?end-diastolic volume (?EDV) and ?ejection fraction (?EF). Myocardial stunning defined either as ?ESV ?5 ml, ?EDV ?5 ml or ?EF ?-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% ?ESV ?5 ml or ?EDV ?5 ml than in those without, whereas ?EF ?-5% did not predict events. Multivariate analysis demonstrated that LVEF ?45% was the independent predictor for cardiac events. Nevertheless, ?EDV ?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)

  11. Assessment of ischemic heart disease by dipyridamole stress electrocardiographic gated myocardial single photon emission computed tomography with technetium-99m tetrofosmin

    International Nuclear Information System (INIS)

    Simultaneous assessment of stress perfusion and rest function is possible with gated single photon emission computed tomography (SPECT) using stress injected technetium-99m (99mTc) tetrofosmin (TF). The feasibility of dipyridamole stress electrocardiographic gated myocardial SPECT (GSPECT) with TF was examined as an alternative to conventional stress/rest imaging. Fifty-one patients underwent stress GSPECT. 740 MBq of TF was administered 3 min after dipyridamole infusion. GSPECT acquisition was performed one hour after the injection. Additional rest SPECT was performed on another day only in patients with abnormal perfusion on stress images. Perfusion and thickening were analyzed visually on 17 segments of the left ventricle. Percentage of wall thickening (%WT) was also calculated in 17 segments of the polar map. Thirty-two of 51 patients (63%) had normal stress perfusion and normal rest thickening. Nineteen of 51 patients (37%) had abnormal perfusion on stress images. Among 157 abnormal perfusion segments of the 19 patients, 139 segments (89%) had thickening and the rest (11%) had no thickening. %WT was higher in the reversible segments with or without thickening. There was better agreement for the identification of normal segments and the presence of reversibility between stress GSPECT and the conventional stress/rest study in patients without previous myocardial infarction than in those with previous myocardial infarction (89% vs 79%). These results suggest that stress GSPECT may substitute for conventional stress/rest perfusion study in patients without previous myocardial infarction, allowing shorter examination time and lower cost. However, stress GSPECT does not replace the need for rest perfusion study in patients with previous myocardial infarction, because of underestimation of viability, but %WT may eliminate this underestimation. (author)

  12. 99mTc-MIBI and 201Tl imaging of thyroid with cold nodule

    International Nuclear Information System (INIS)

    Objective: To investigate clinical value of 99mTc-MIBI and 201Tl imaging of thyroid with cold nodule. Methods: 87 patients with cold thyroid nodule were imaged with 99mTc-MIBI (early 15 min, delayed 60 min) and 201Tl (early 15 min, delayed 120 min). Results of interest (ROIs) were generated over the cold nodule and normal tissue on each image by semi-quantification method. The semi-quantitative analysis was performed by using a lesion to non-lesion ratio of early (ER) and delayed (DR) images. Retention index (RI) was calculated by dividing delayed-early subtraction to product ER. Results: there was significant difference in the ER, DR and RI between malignant and benign lesions for 99mTc-MIBI and 201Tl (p0.05), but there was significant difference between carcinoma and cystic adenoma for 201Tl imaging (p99mTc-MIBI and 201Tl imaging of thyroid cold nodule using ER, DR and RI have good clinical application value

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

    Energy Technology Data Exchange (ETDEWEB)

    Taki, Junichi; Ichikawa, Akihiro; Nakajima, Kenichi; Tonami, Norihisa [Department of Nuclear Medicine, Kanazawa University School of Medicine, Kanazawa (Japan); Kawasuji, Michio [Department of Surgery (I), Kanazawa University School of Medicine, Kanazawa (Japan)

    1997-12-01

    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 {sup 201}Tl 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.) With 2 figs., 4 tabs., 32 refs.

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

    International Nuclear Information System (INIS)

    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.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Cannon, R.O. 3d.; Dilsizian, V.; O' Gara, P.T.; Udelson, J.E.; Schenke, W.H.; Quyyumi, A.; Fananapazir, L.; Bonow, R.O. (National Institutes of Health, Bethesda, MD (USA))

    1991-05-01

    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 {sup 201}Tl scintigraphy and, during the same week, measurement of myocardial lactate metabolism and hemodynamics during pacing stress. Thirty-seven patients (74%) had one or more {sup 201}Tl abnormalities that completely normalized after 3 hours of rest; 26 had regional myocardial {sup 201}Tl 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 {sup 201}Tl abnormalities, 27 (73%) had metabolic evidence of myocardial ischemia during rapid atrial pacing compared with four of 13 patients (31%) with normal {sup 201}Tl scans (p less than 0.01). Eleven patients had apparent cavity dilatation as their only {sup 201}Tl abnormality; their mean postpacing left ventricular end-diastolic pressure was significantly higher than that of the 13 patients with normal {sup 201}Tl 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 {sup 201}Tl abnormalities. Patients with ischemic ST segment responses to exercise had an 80% prevalence rate of reversible {sup 201}Tl abnormalities and a 70% prevalence rate of pacing-induced ischemia. However, 69% of patients with nonischemic ST segment responses had reversible {sup 201}Tl abnormalities, and 55% had pacing-induced ischemia. Reversible {sup 201}Tl abnormalities during exercise stress are markers of myocardial ischemia in hypertrophic cardiomyopathy and most likely identify relatively underperfused myocardium.

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

    International Nuclear Information System (INIS)

    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

  17. Evaluation of myocardial viability with technetium-99m hexakis-2-methoxyiso-butylisonitrile and iodine-123 phenylpentadecanoic acid and single photon emission tomography

    International Nuclear Information System (INIS)

    We applied combined planar and single photon emission tomography (SPET) to the non-invasive estimation of the left ventricular ejection fraction (LVEF), myocardial blood flow and free fatty acid uptake in the heart. Of the 31 patients with coronary artery disease, 25 had a previous myocardial infarction. All patients had at least one persistent perfusion defect on the stress-rest technetium-99m-Sestamibi study, and the results revealed 46% persistent perfusion defects. As a part of the perfusion study, the LVEF was measured at rest using the first-pass 99mTc-Sestamibi injection. Iodine-123 pPPA imaging at rest was performed within 2 weeks of the perfusion study. The 6-mm transaxial, sagittal and coronal slices of the perfusion and 123I-pPPA studies were reconstructed. Moreover an index of metabolic reserve (MR) was calculated by dividing the bull's eye of the 123I-pPPA study by the bull's eye of resting 99mTc-Sestamibi. Fourteen segments (25%) had a normal 123I-pPPA uptake with a MR value of 96%. Twenty-two segments (39%) had a partial 123I-pPPA uptake with a MR of 74%, whereas 21 segments (36%) had no 123I-pPPA uptake and a very low MR of 36%. There was a highly significant correlation between LVEF and MR. These findings suggest that it is possible to identify viable myocardium by measuring contractile function and myocardial perfusion and by combining these parameters with myocardial fatty acid uptake studies. (orig.)

  18. Estimation of Myocardial Ischemia by Diastolic Strain Analysis in Exercise Stress Echocardiography. Comparison with exercise thallium-201 single photon emission computed tomography

    International Nuclear Information System (INIS)

    The feasibility of detecting persistent regional left ventricular abnormal relaxation due to myocardial ischemia using strain echocardiography several minutes after exercise was investigated. Consecutive 27 patients (mean age 65±9 years, 21 males, 6 females) with suspected coronary artery disease were enrolled. Strain echocardiographic images were acquired at the mid segments of the left ventricular wall before and 5 min after exercise in the apical long-axis, two-chamber and four-chamber views. Strain curves were obtained at each segment, and peak values of strain at the closure of aortic valve (A) and at one third of diastolic duration (B) were measured. Strain diastolic index (SDI) was calculated as (A-B)/A x 100%. The ratio of SDI before exercise to that after exercise was defined as the SDI ratio and compared with exercise thallium-201 single photon emission computed tomography (SPECT) as the reference standard to detect myocardial ischemia. A total of 162 segments were evaluated. Based on the results of exercise SPECT, 119 segments were classified as non-ischemic segments, and 43 as ischemic segments. Ischemic segments showed significant decreases in SDI before and after exercise, whereas non-ischemic segments showed no significant differences in SDI before and after exercise. SDI ratio was significantly decreased in ischemic segments, but not in non-ischemic segments. SDI ratio with a cut off value of 0.51 had a sensitivity of 91% and a specificity of 89% to detect myocardial ischemia in the receiver-operating characteristics. Strain echocardiography can provide quantitative assessment of myocardial ischemia by detecting post-ischemic regional left ventricular delayed relaxation even 5 min after exercise. (author)

  19. Removal of 99mTc and 201Tl by means of Lemna Gibba

    International Nuclear Information System (INIS)

    In this work the capacity of the water macrophyte Lemna gibba coming from San Pedro Tultepec in the Mexico State was studied to remove the radioisotopes 99mTc and 201Tl, in order to show the capacity of this macrophyte for to treat some radioactive waste flowing that could contain this radioisotopes type. The removal capacity of 99mTc and 201Tl of the macrophyte Lemna gibba was determined using the batch method. In accordance with the values of the obtained Kd, the Lemna gibba with a size of particle diameter among 1mm - 300 ?m presents a better adsorption of 99mTc. The 201Tl is adsorbed better in the bioadsorbent when it has a size of particle diameter <150?m. (Author)

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Strydhorst, Jared H., E-mail: jared.strydhorst@gmail.com; Ruddy, Terrence D.; Wells, R. Glenn [Cardiac Imaging, University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, Ontario K1Y 4W7 (Canada)

    2015-04-15

    Purpose: Our goal in this work was to investigate the impact of CT-based attenuation correction on measurements of rat myocardial perfusion with {sup 99m}Tc and {sup 201}Tl single photon emission computed tomography (SPECT). Methods: Eight male Sprague-Dawley rats were injected with {sup 99m}Tc-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 {sup 201}Tl 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 {sup 99m}Tc in the heart was also quantified with and without attenuation correction. Results: For {sup 99m}Tc 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 {sup 201}Tl images. Interscan and inter-rat reproducibilities of relative segmental perfusion were 2.7% and 3.9%, respectively, for the uncorrected {sup 99m}Tc scans, and 3.6% and 4.3%, respectively, for the {sup 201}Tl 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.

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

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

  4. 201Tl brain SPECT in differentiating central nervous system lymphoma from toxoplasmosis in AIDS patients

    International Nuclear Information System (INIS)

    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)

  5. High-contrast film copying for 201Tl cardiac image processing

    International Nuclear Information System (INIS)

    To evaluate the usefulness of high-contrast film copying as an economical means of enhancing contrast in 201Tl cardiac images, stress and rest studies of 47 patients with and 19 patients without coronary artery disease were evaluated. A total of 66 sets of four different image formats were independently interpreted by five observers. The analysis of the receiver operating characteristic curves suggested that the high-contrast film copies were superior to their original analog images and comparable with computer-processed images in diagnostic yield. It appears that contrast enhancement by simple film copying can improve the accuracy of 201Tl image interpretation

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

    International Nuclear Information System (INIS)

    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 tabTo 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 <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. h

  7. Clinical studies on thallium-201 myocardial perfusion imaging in patients with ischemic heart disease

    International Nuclear Information System (INIS)

    201Tl myocardial perfusion imaging in patients with ischemic heart disease was discussed. Infarcted areas, which had been diagnosed with electrocardiograms and coronary arteriograms of 27 patients with cardial infarction, were visualized as a decrease or a defect of myocardial uptake of 201Tl on their rest myocardial perfusion images (MPI). The pictures of them obtained from rest MPI were well correlated with their coronary arteriograms. Myocardial uptake of 201Tl was increased by exercise in normal subjects, but decreased uptake of RI was observed on stress MPI of 12 patients with effort angina and 5 of 6 patients with cardial infarction. These findings were also observed in their postexertion electrocardiogram. To visualize images more clearly, an phantom experiment was performed and clear images close to the actual size were obtained. Ratio of myocardial uptake of 201Tl in ischemic areas after exercise was decreased significantly in patients with angina and cardiac infarction, though myocardial uptake of 201Tl in healthy subjects was not changed by exercise. A defect of myocardial uptake of 201Tl was induced by methacholine in 4 patients with a variant form of angina and was induced by exercise in 2. Improvement of myocardial uptake of 201Tl was observed on images of patients in whom blood flow in local myocardium had been improved after the operation to make bypass. (Tsunoda, M.)

  8. Effects of exercise on kinetics and distribution of 43K and 201Tl in isolated myocardium: concise communication

    International Nuclear Information System (INIS)

    Kinetics and distribution of K-43 and Tl-201 were studied in isolated myocardial tissue from rats to assess the effects of exercise. The experimental design was as follows. Rats in some groups were forced to swim for 2 hr; immediately after swimming, they were injected with 0.2 mCi of 43KCl or 201TlCl; at 0.5 or 3 hr after injection they were killed and a myocardial segment was obtained and subjected to washouts with nonradioactive Krebs fluid in a special chamber. The radioactivity remaining in the tissue was recorded continuously for 1 hr. In control groups (''rested'') the exercise was omitted. Altogether there were four groups of ten animals each for both K-43 and Tl-201. A three-compartment model (extracellular, main intracellular, and subcellular) was used; transport rate constants and relative compartment sizes were determined. The most striking finding was the unchangeability of K-43 parameters with regard to experimental condition (rest compared with exercise) and sampling time (0.5 compared with 3 hr after radionuclide injection). On the other hand, Tl-201 parameters were modified by exercise and sampling time. Notable differences between K-43 and Tl-201 kinetics were found. The hypothesis that alterations at the cellular level may affect regional myocardial distribution of a radionuclide is discussed

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

    Energy Technology Data Exchange (ETDEWEB)

    Bartram, P.; Hanel, B.; Gustafsson, F.; Mortensen, J.; Hesse, B. [Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital (Denmark); Toft, J. [Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital (Denmark)]|[Copenhagen City Heart Study, Epidemiological Research Unit (Denmark); Ali, S. [Dept. of Cardiology, Copenhagen University Hospital (Denmark)

    1998-09-01

    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.) With 1 fig., 26 tabs., 22 refs.

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

    International Nuclear Information System (INIS)

    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.)

  11. Phantom study of thallium-201 myocadial single photon emission computed tomography for evaluating its ability to quantify residual myocardium in infarct area

    International Nuclear Information System (INIS)

    We studied the relationship between the count of myocardial wall in single photon emission computed tomography (SPECT) image and the thickness of wall or the concentration of Thallium-201 (Tl) in wall. For this purpose, we used phantom of thorax and myocardium. Thoracic phantom consists of mediastinum filled with low concentrated Tl solution and lung filled with wooden tip. Myocardial phantom consists of eight parts (upper and lower parts of anterior wall, septum, posteroinferior wall and lateral wall). In one phantom we changed the thickness of wall (10 mm, 7.5 mm, 5 mm, 2.5 mm, 0 mm) and in another phantom we changed the Tl concentration (100 %, 75 %, 50 %, 25 %, 0 %). In our results, the thickness and the concentration correlated well with the count and five grades (100 %, 75 %, 50 %, 25 %, 0 %) were well separated though it was said that SPECT is inaccurate in quantification. But in 180 deg half scan, the count of upper part was 10 - 15 % lower than that of lower part and the count of posteroinferior wall was about 10 % lower than that of anterior wall. We have to take it into account in quantification. In conclusion, using Tl-201 myocardial SPECT residual myocardium in infarct area can be evaluated from the severity of defect, and from that the severity of ischemia can be evaluated. (author)

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

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    Chen, Liguang; Nohara, Ryuji; Hirai, Taku [Kyoto Univ. (Japan). Graduate School of Medicine] (and others)

    2001-06-01

    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 ({sup 201}Tl) and {sup 123}I-({rho}-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 {sup 201}Tl and BMIPP ({sup 201}Tl, 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)

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

    International Nuclear Information System (INIS)

    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-(?-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)

  14. Evaluation of 201Tl-DDC as a cerebral blood flow tracer

    International Nuclear Information System (INIS)

    We studied rCBF in 28 patients (cerebrovascular disease, epilepsy, migraine, dementia) by means of 201Tl-DDC (Diethyldithiocarbamate) and SPECT and, for comparison, all patients underwent also a control SPECT study with IMP or HMPAO. DDC-SPECT images are comparable to SPECT images using IMP or HMPAO. In addition, DDC seems to offer some advantages. (orig./MG)

  15. Segmental analysis of 201-Tl emission computerized tomography of the heart. Evaluation by coronarographic data

    International Nuclear Information System (INIS)

    Segmental analysis of SPECT 201-Tl stress study of the heart is a very sensitive and specific method highly predictive for coronary arteriosclerotic disease in the studied population. Distinction between single and multivessel disease was possible in 75% of the cases. In comparison with planar scintigraphy anomalies of the infero-posterior wall are better visualized

  16. Incomplete redistribution in delayed thallium-201 single photon emission computed tomographic (SPECT) images: an overestimation of myocardial scarring

    International Nuclear Information System (INIS)

    To determine if incomplete redistribution at 4 h in exercise tomographic thallium-201 studies is always due to a myocardial scar, 141 patients were evaluated before and after a total of 160 successful percutaneous transluminal coronary angioplasty procedures. Thallium studies were analyzed using polar bull's-eye maps. For both immediate and delayed images, abnormalities were quantified as a thallium score by calculating a standard deviation-weighted sum of pixels greater than 2.5 SD below gender-matched normal limits. One hundred forty-four of 160 studies indicated abnormalities before angioplasty. Of these 144, incomplete redistribution occurred in 111 (77%): 16 (14%) in patients with and 95 (86%) in patients without prior Q wave myocardial infarction. After angioplasty, improvement in delayed image score occurred in 8 (50%) of 16 patients with prior infarction and 72 (76%) of 95 patients without prior infarction (p less than 0.05). After angioplasty, delayed images were normal in 1 (6%) of 16 patients with prior infarction and 32 (34%) of the 95 without (p less than 0.05). Before angioplasty, delayed image scores were positively correlated with scores in the immediate postexercise images in patients with (r = 0.84) and those without (r = 0.69) prior infarction. To determine if additional delayed images could help differentiate scar from ischemia, an 8 to 24 h delayed image was obtained in each of 40 other patients with incomplete redistribution at 4 h. Of 28 patients without prior infarction, 15 had no redistribution, and 13 had further redistribution at 8 to 24 h

  17. Estimation of the lung uptake ratio of 201Tl in cardiopulmonary diseases

    International Nuclear Information System (INIS)

    On intravenous administration of 201TlCl (2-3mCi), the initial transit of it through the heart and lungs as well as subsequent uptake by the lung were recorded in the supine position using a scintillation camera coupling to a small digital computer. Leaving the patient in the same position the anterior image of perfusion lung scintigram with sup(99m)Tc-macroaggregated albumin or transmission scintigram with a point source of sup(99m)TcO4- taken. The radioactivity of total injected dosage (T) was calculated from the counts of the entire region on the initial transit of the tracer bolus through the heart and lungs, and counts per each pixel (E), total counts (L) and number of pixels (A) in the unilateral lung were calculated from the anterior image of 201Tl on which the isocount map of the perfusion lung scintigram or transmission one was superimposed. By these procedures, the uptake ratio of 201Tl per unilateral lung, the mean and each uptake ratio per pixel in the unilateral lung were calculated by L/T, L/T.A and E/T. Following results were obtained; 1) The mean value of the uptake ratio of it per unilateral lung in the right and left lung, were 1.5+-0.9%, 1.2+-0.6% in healthy lung; 3.2+-1.7%, 1.8+-1.0% in diffuse pulmonary diseases and 4.0+-1.6%, 2.5+-1.3% in cardiac diseases with left heart failure, respectively. 2) In the two groups using the perfusion lung scintigram and transmission one, the mean uptake ratio per pixel and number of pixels in the unilateral lung showed significant difference, but the uptake ratio per the unilateral lung did no significant difference. 3) These techniques are seemed to be useful for quantifying the lung uptake ratio of 201Tl on the lung scintigram with 201TlCl. (author)

  18. Myocardial infarction determined by technetium-99m pyrophosphate single-photon tomography complicating elective coronary artery bypass grafting for angina pectoris

    International Nuclear Information System (INIS)

    The incidence of acute myocardial infarction (AMI) complicating coronary artery bypass grafting (CABG) has previously been based on concordance of electrocardiographic, enzymatic and scintigraphic criteria. Technetium-99m pyrophosphate (Tc-PPi) single-photon emission computed tomography now enables detection of AMI with high sensitivity and specificity. Using this technique, perioperative AMI was detected in 12 of 58 patients (21%) undergoing successful elective CABG for stable angina pectoris. Stepwise multivariate logistic regression analysis was performed to compare the predictive value of preoperative (New York Heart Association class, left ventricular ejection fraction and use of beta blockers) and intraoperative (number of grafts constructed, use of internal mammary anastomoses, use of sequential saphenous vein grafts, smallest grafted distal vessel lumen caliber and aortic cross-clamp time) variables. Preoperative New York Association class (p = 0.04) and smallest grafted distal vessel lumen caliber (p = 0.03) were significant multivariate predictors of perioperative AMI. Only 1 perioperative patient with AMI (and 1 pyrophosphate-negative patient) developed new Q waves. Serum creatine kinase-MB was higher in patients with AMI by repeated measures analysis of variance (p = 0.0003). Five AMIs occurred in myocardial segments revascularized using sequential saphenous vein grafts, and 7 in segments perfused by significantly stenosed epicardial vessels with distal lumen diameter and perfusion territory considered too small to warrant CABG. At 6-month follow-up, the mean left ventricular ejection fraction increased from 0.61 to 0.65 in Tc-PPI-negative patients (p = 0.01), but not in perioperative patients with AMI

  19. Iodine-123 N-methyl-4-iododexetimide: a new radioligand for single-photon emission tomographic imaging of myocardial muscarinic receptors

    International Nuclear Information System (INIS)

    Cardiac muscarinic receptor ligands suitable for positron emission tomography have previously been characterised. Attempts to develop radioligands of these receptors suitable for single-photon emission tomographic (SPET) imaging have not been successful due to high lung retention and high non-specific binding of previously investigated potential tracers. The purpose of this study was to evaluate the biodistribution and in vivo imaging characteristics of a new radiopharmaceutical, [123I]N-methyl-4-iododexetimide. Biodistribution studies performed in rats showed high cardiac uptake (2.4% ID/g) 10 min after injection with a heart to lung activity ratio of 5:1. Specificity and stereoselectivity of cardiac binding were demonstrated using blocking experiments in rats. Dynamic imaging studies in anaesthetised greyhounds demonstrated rapid and high myocardial uptake and low lung binding with stable heart to lung activity ratios of >2.5:1 between 10 and 30 min, making SPET imaging feasible. Administration of an excess of an unlabelled muscarinic antagonist, methyl-quinuclidinyl benzylate rapidly displaced myocardial activity to background levels and the pharmacologically inactive enantiomer, [123I]N-methyl-4-iodolevetimide, had no detectable cardiac uptake, indicating specific and stereoselective muscarinic receptor binding. SPET revealed higher activity in the inferior than in the anterior wall, this being consistent with previously described regional variation of cardiac parasympathetic innervation. [123I]N-methyl-4-iododexetimide shows promise as an imaging agent for muscarinic receptor distribution in the heart and may be helpful in evaluating diverse cardiac diseases associated with altered muscarinic receptor function, including heart failure and diabetic heart disease. (orig.)

  20. Measurement of infarct size in acute canine myocardial infarction by single-photon emission computed tomography with technetium-99m pyrophosphate

    International Nuclear Information System (INIS)

    The location and extent of myocardial infarction (MI) are important predictors of patient course. The current study tests the hypothesis that MI size could be measured accurately using rotating gamma camera single-photon emission computed tomography (SPECT) and technetium-99m pyrophosphate (PPi) and that the accuracy of these measurements was independent of MI location and transmural or nontransmural distribution. SPECT was performed in 38 dogs 48 hours after ligation of the left anterior descending coronary artery (14 dogs) or left circumflex coronary artery (LC) (24 dogs) at the mid-level or below. The boundary of PPi uptake in each slice was marked automatically using an algorithm that combined a directional derivative and a threshold, and required continuity of the boundary in 3 dimensions. The total number of volume elements that showed abnormal tracer uptake were summed, corrected to absolute volume, and multiplied by the specific weight of cardiac muscle. Scintigraphic MI weight was compared with pathologic MI weight. There was an excellent correlation between scintigraphic and pathologic MI weight. The poorer correlation for nontransmural compared with transmural MIs is most likely a function of size alone

  1. Medium- to long-term prognostic impact of dipyridamole thallium-201 myocardial single-photon emission computed tomography in elderly patients

    International Nuclear Information System (INIS)

    Dipyridamole thallium-201 single-photon emission computed tomography (SPECT) has not been extensively evaluated for risk stratification and the medium- to long-term prognostic value in elderly cardiac patients who are unable to exercise. The present study group comprised 210 consecutive patients aged at least 70 years with known or suspected coronary artery disease (CAD). The SPECT findings were classified as a reversible, fixed, or combined (reversible and fixed) defect. Of the 210 patients, 201 (77±5 years, 85 male) were successfully followed for 49±26 months. Thirteen (7%) patients had cardiac events: cardiac death (n=10), non-fatal myocardial infarction (n=1), or coronary artery bypass grafting (n=2). Cardiac events occurred in 3 of 112 patients with normal SPECT and in 10 of 89 patients with an abnormal scan (0.7%/year vs 2.8%/year, p=0.01). Stepwise Cox regression analysis revealed that the significant predictors of cardiac events were combined defects (relative risk 7.3) and the number of defect areas (relative risk 4.4). The predictive value of dipyridamole thallium-201 SPECT is maintained over 4 years in mixed populations of elderly CAD patients who are unable to exercise. (author)

  2. 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

    Energy Technology Data Exchange (ETDEWEB)

    Koitabashi, Norimichi; Toyama, Takuji; Hoshizaki, Hiroshi [Gunma Prefectural Cardiovascular Center, Maebashi (Japan)] [and others

    2000-04-01

    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 V{sub 2}, V{sub 3} and V{sub 4} leads. In patients with angina pectoris, ST depression was frequently found in the II, III, aV{sub F}, V{sub 5} and V{sub 6} 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)

  3. 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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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 thery disease detection with reference to the angiographic data. (orig.). With 14 figs., 2 tabsA 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 t

  5. Superconducting Single Photon Detectors:

    OpenAIRE

    Dorenbos, S. N.

    2011-01-01

    This thesis is about the development of a detector for single photons, particles of light. New techniques are being developed that require high performance single photon detection, such as quantum cryptography, single molecule detection, optical radar, ballistic imaging, circuit testing and fluorescence spectroscopy. Superconducting single photon detectors (SSPDs) are sensitive to single photons from the ultraviolet to the near infrared. In this thesis steps has been taken towards improvi...

  6. Evaluation of cellular viability by quantitative autoradiographic study of myocardial uptake of a fatty acid analogue in isoproterenol-induced focal rat heart necrosis

    International Nuclear Information System (INIS)

    Previous studies led us to hypothesize that a fatty acid analogue, 15-p-iodophenyl-?-methyl pentadecanoic acid (IMPPA or BMIPP), which is taken up but not quickly metabolized by heart cells, would be a more suitable tracer of cellular viability that 201Tl. Biodistribution studies of 1-14C-IMPPA in conscious, freely moving rats showed that the concentration ratio of radioactivity in the heart with respect to the blood was about 8 for at least 60 min after intravenous administration, permitting its use as a putative tracer in these conscious, freely moving rats. Thereafter, the myocardial uptake of 14C-IMPPA was studied in isoproterenol-treated rats (daily treatment for 10 days in order to induce cardiac hypertrophy and necrotic foci) with respect to control ones. Comparison of myocardial localizations by quantitative autoradiography of the uptake of 201Tl and 14C-IMPPA with that of triphenyltetrazolium chloride (TTC) staining enabled comparative evaluation of nutritional blood flow, localization and uptake of 14C-IMPPA and necrotic foci size. Distributions of 14C-IMPPA and 201Tl in control rats' hearts were homogenous, like TTC staining. In infarcted hearts, areas of decreased 14C-IMPPA uptake were nearly the same (100%±5%) as those unstained by TTC. These areas were larger than those showing a decrease in thallium uptake (about 70%±5% of the total scar size). Therefore, IMPPA seems to be a more accurate and sensitive indicator of necrosis localization compared with thallium. It may be a useful agent for assessment of myocardial viability by single photon emission tomography (SPET) imaging. (orig.)

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

    International Nuclear Information System (INIS)

    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 ? 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 than conventional SPECT. Further assessment in a larger patient population may be needed to confirm this observation. (orig.)

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

    International Nuclear Information System (INIS)

    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. ? 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 0.04. Sensitivity, specificity, negative and positive predictive values for SPECT were, respectively, 100%, 75%, 100% and 60%. For MCE these values were, respectively, 20%, 76%, 71.4% and 50%. Conclusion: SPECT demonstrated to be a reliable technique in the discrimination of patients with an ACE among those who were admitted with acute chest pain at emergency room. MCE was less useful in this setting

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

    Energy Technology Data Exchange (ETDEWEB)

    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 assessment better than conventional SPECT. Further assessment in a larger patient population may be needed to confirm this observation. (orig.)

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

    International Nuclear Information System (INIS)

    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 irrespective of CACS. Further studies incorporating prognostic follow- up are required. (author)

  11. 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

    International Nuclear Information System (INIS)

    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.)

  12. Indications and evaluation of coronary artery bypass grafting with myocardial single photon emission tomography using 123I-BMIPP. A new tracer of myocardial metabolism of fatty acid

    International Nuclear Information System (INIS)

    To evaluate viability and severity of ischemically damaged myocardium,myocardal single emission tomography (SPECT) using 123I-BMIPP (BMIPP), a new tracer of myocardial metabolism of fatty acid, was performed before and after coronary artery bypass grafting (CABG). 201TI myocardial SPECT (TI) and left ventriculography (LVG) were also used.Thirty-three revascularized areas in eight patients were investigated. Areas showing good redistribution on TI and normal uptake on BMIPP indicated good viability and simple ischemic myocardium. Postoperative uptake of both tracers returned to normal levels. Areas showing good redistribution on TI and severely decreased uptake on BMIPP indicated jeopardized myocardium with severe ischemia. All such areas were seen in patients with unstable angina.Postoperative uptake of both tracers returned to normal levels. Areas showing poor redistribution or severely decreased uptake on TI and slight uptake on BMIPP indicating hibernating areas. Postoperative uptake became normal or better than preoperative uptake on TI necrosis. However on BMIPP, the uptake was unchanged or recovered slightly. Areas showing complete defect in TI and BMIPP indicated necrosis and had no viabilty. Postoperatively the defect in both tracers were unchanged. Therefore, these areas required no revascularization. The ischemic state of myocardium could be assessed by evaluation of uptake patterns of BMIPP and TI using myocardial SPECT. Therefore, using this new tracer of myocardial fatty acid metabolism 'BMIPP' is useful for deciding culprit and viable lesions requiring coronary revascularization and evaluating therapeutical effects

  13. Study of myocardial viability using thallium-201 in patients with a history of infarctions: Is reinjection necessary?

    International Nuclear Information System (INIS)

    An analysis was performed of 84 patients with a history of myocardial infarction using the thallium-single photon emission computed tomography (SPECT) test and employing the technique of reinjection of the radioisotope 201Tl at rest. A study was conducted during the period of maximum stress, four hours and one hour after reinjection of 37 MBq of 201Tl. The presence and extent of reperfusion was determined. In addition, the incidence of ischaemia was correlated with four clinical parameters which might influence its occurrence: development period of the infarction (greater or less than 30 days), Q wave in the electrocardiogram, prior use of streptokinase, and angina. Twenty-seven patients exhibited partial reperfusion at rest which increased significantly in 14 of the patients after thallium reinjection. Moreover, 22 patients only exhibited reperfusion with reinjection. There was no relation between the clinical parameters evaluated and the incidence of ischaemia. In conclusion, with thallium reinjection 43% more patients can be detected with viable areas of myocardium which are not evident at rest. The clinical parameters evaluated are no help in predicting ischaemia with thallium. The routine use of reinjection is recommended to evaluate myocardial viability in patients with a history of infarction. (author). 14 refs, 2 figs

  14. Use of 123I-BMIPP single-photon emission tomography to estimate areas at risk following successful revascularization in patients with acute myocardial infarction

    International Nuclear Information System (INIS)

    Previous studies have indicated that iodine-123 labelled ?-methyliodophenyl pentadecanoic acid (BMIPP), an iodinated fatty acid analogue, can identify persistent alteration of fatty acid metabolism after restoration of blood flow. To assess whether fatty acid imaging can delineate areas at risk following successful revascularization in patients with acute myocardial infarction (AMI), BMIPP findings at 1 week post AMI were compared with perfusion imaging before and after revascularization therapy. Sixty-five patients with AMI underwent technetium-99m tetrofosmin single-photon emission tomography (SPET) before m (TF0) and 1 week (TF1) after successful revascularization therapy. BMIPP SPET was also performed under a fasting state at 1 week (BM1) post AMI. The extent scores were calculated from the defect scores in 20 segments. The BM1 score (7.7±3.9) was similar to the TF0 score (8.8±4.2) (r=0.86, P<0.0001), but significantly higher than the TF1 score (5.8±3.9) (P<0.0001). A significant correlation was observed between the BM1 score and TF0 score (r=0.86, P<0.0001). Among a total of 1300 segments, the BM1 score was identical to the TF0 score in 1156 (88.9%). These data indicate that the ability of BMIPP imaging at 1 week post AMI to identify areas at risk is similar to that of tetrofosmin perfusion imaging in the acute phase. This may be due to the impairment of fatty acid uptake and metabolism reflecting prior severe ischaemic insult which persists at least 1 week after recovery of perfusion in the acute phase of AMI. (orig.)

  15. Classification of 201TL and sup(99m)Tc-pertechnetate leg scan patterns and evaluation of their clinical significance

    International Nuclear Information System (INIS)

    Classification of the 201Tl and sup(99m)Tc-pertechnetate (sup(99m)TcOsub(4-)) leg scan patterns and their clinical significance were evaluated in the patients with ischemic diseases of the lower extremities (IDL) Five patterns were distinguished in both 201Tl and sup(99m)TcOsub(4-) leg scans; A: decreased activity throughout the affected leg, B: localized decreased activity in the affected leg, C: localized decreased activity associated with increased activity in the affected leg, D: generalized of localized increased activity in the affected leg and E: no laterality of the activity. 201Tl and sup(99m)TcOsub(4-) leg scan patterns were agreed in 55% of the patients. 201Tl leg scan had tendency to correlate the level of the vascular lesion in pattern B and C,However, diagnosis of the level of the lesion was difficult from the leg scan. Pattern D of the 201Tl leg scan was associated with increased blood flow in the affected leg on radionuclide angiography in 42% of the patients. After surgery, sup(99m)TcOsub(4-) leg scan tended to show pattern D, especially in the patients with lumbar sympathectomy. Patterns A, B and C were thought to suggest the ischemia. Patterns C and D were thought to express reactive hyperemia induced by the ischemic lesion. In the 60 preoperative IDL, sensitivity of 201Tl leg scan alone was 76% and that of combined use of 201Tl and sup(99m)TcOsub(4-) leg scans was 85%. Addition of radionuclide angiography increased sensitivity of IDL upto 98% and accuracy was 98%. Combined use of 201Tl and sup(99m)TcOsub(4-) leg scans and radionuclide angiography was useful for detection of IDL, and was also useful for evaluation of the results of the surgical intervention. (J.P.N.)

  16. Dosimetry of four heart-imaging radionuclides: 43K, 81Rb, 129Cs, and 201Tl

    International Nuclear Information System (INIS)

    In conjunction with research into the relative clinical suitability of radionuclides for heart imaging, estimates of the radiation dose from 43K, 81Rb, 129Cs, and 201Tl were calculated. Estimates of absorbed radiation dose for the heart, kidneys, liver, lungs, testes, and whole body of the standard man were computed from published distribution data in rats via the MIRD method by assuming that the concentration in each organ per initial mean whole-body concentration is the same in rats and humans. The whole-body absorbed radiation doses from 81Rb, 129Cs, 201Tl, and 43K are 0.08, 0.17, 0.24, and 0.60 rads/mCi administered intravenously. In general, the organ doses for the four radionuclides follow the same order

  17. Effects of low-dose dobutamine on left ventricular function in normal subjects as assessed by gated single-photon emission tomography myocardial perfusion studies

    Energy Technology Data Exchange (ETDEWEB)

    Everaert, H.; Vanhove, C.; Franken, P.R. [Div. of Nuclear Medicine, University Hospital, Free University of Brussels (Belgium)

    1999-10-01

    Electrocardiography gated single-photon emission tomography (gated SPET) allows the assessment of regional perfusion and function simultaneously and in full spatial congruency. In this study changes in global and regional left ventricular function in response to dobutamine infusion were assessed in ten healthy volunteers using sequential gated SPET myocardial perfusion acquisitions. Four consecutive gated SPET images were recorded 60 min after injection of 925 MBq technetium-99m tetrofosmin on a three-head camera equipped with focussing collimators. Two acquisitions were made at rest (baseline 1 and 2), and the third and fourth acquisitions were started 5 min after the beginning of the infusion of 5 and 10 {mu}g kg{sup -1} min{sup -1} dobutamine, respectively. Systolic wall thickening (WT) was quantified using a method based on circumferential profile analysis. Left ventricular ejection fraction (LVEF) and volumes were calculated automatically using the Cedars-Sinai program. Nine of the ten subjects presented a definite increase in WT during dobutamine infusion. WT increased on average from 46%{+-}14% at baseline to 71%{+-}23% (range: 37%-106%; P<0.05) during 5 {mu}g kg{sup -1} min{sup -1} dobutamine infusion and to 85%{+-}25% (range: 62%-123%; P<0.05 with respect to WT at 5 {mu}g kg{sup -1} min{sup -1}) during 10 {mu}g kg{sup -1} min{sup -1} dobutamine infusion. Apical segments showed the largest WT at baseline. The average WT response to dobutamine was similar for all parts of the myocardium. It is concluded that changes in WT induced by infusion of low-dose dobutamine can be assessed by sequential gated SPET myocardial perfusion studies. The ''stress gated SPET'' protocol proposed in this study might be helpful to distinguish viable from scar tissue in patients with coronary artery disease, by demonstrating a preserved inotropic response in hypoperfused myocardium. (orig.)

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

    International Nuclear Information System (INIS)

    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

  19. Differential diagnosis between recurrence of brain tumor and radiation necrosis by 201Tl SPECT

    International Nuclear Information System (INIS)

    In order to differentiate recurrence of brain tumor from radiation necrosis, we performed 201Tl brain SPECT in 16 post-operative patients. Five of them had residual anaplastic astrocytoma. Final diagnosis of the other 11 patients was recurrent astrocytoma (n=6), cerebral radiation necrosis (n=5), based on re-operation (n=9) and more than one year follow-up findings (n=2). Early and delayed images were obtained at 10?15 min. and 4 hrs. after i.v. injection of 111 MBq of 201Tl chroride. Counts ratio of a lesion to the normal brain (L/N) was calculated by creating rectangular ROI over each area. All of the patients with recurrent or residual tumor showed L/N ratios of more than 2.5 on the early images (mean 4.70 ± 2.65). On the other hand, L/N ratios on the early images were less than 2.5 in patients with radiation necrosis (mean 2.05 ± 0.25, p201Tl brain SPECT may be useful in differentiating recurrence of brain tumor from radiation necrosis. (author)

  20. The diagnostic significance of diffuse lung uptake of 201Tl chloride in diffuse interstitial pneumonia

    International Nuclear Information System (INIS)

    Scintigraphy with 201TlCl and 197HgCl2 was performed in 323 patients with various respiratory diseases. Diffuse, marked bilateral lung uptake of 201Tl or 197Hg was demonstrated in 2 of 3 cases with hypersensitivity pneumonitis, 26 of 29 cases with silicosis and 28 of 29 cases with diffuse interstitial pneumonia, but in diffuse panbronchiolitis, chronic bronchitis and pulmonary emphysema, only slight lung uptake or negative results were obtained in most cases. In diffuse interstitial pneumonia, no close correlation was observed between the grade of the lung uptake and the various clinical findings such as fever, cough, rales, ESR, S-LDH, ?1-globulin, %VC, PaO2 and so on. With regard to roentgenological findings, marked lung uptake was observed in cases not only with reticulonodular shadows but also those with ring shadows and those without any shadows. Concerning the microscopic findings of lung biopsy specimens, marked uptake was observed in cases with slight interstitial fibrosis as well as infiltration of mononuclear cells. The right ventricle was visualized in 13 of 19 cases (68.4%) with diffuse interstitial pneumonia. Lung scintigraphy with 201Tl chloride is non-invasive and seems a more sensitive indicator of diffuse intersitial changes such as inflammatory disorders than the clinical findings, chest X-ray and so on. (author)

  1. Biodistributions of radioactive alkaline metals in tumor bearing animals: Comparison with 201Tl

    International Nuclear Information System (INIS)

    The retention values for 42K, 86Rb and 134Cs in the tissues and blood were quite similar to those for 201Tl, but were very different from those for 22Na. In an experiment for subcellular fractionation of tumors, most of these nuclides were localized in the supernatant fraction, with small amounts in other fractions. The concentration ratios for these nuclides in each fraction were approximately constant regardless of the time after administration. Radioactive alkaline metals in the supernatant fraction of the tumor homogenate existed mostly as free ions and were bound to protein in other fractions of tumor tissue. These results were essentially the same as those for 201Tl. Ouabain suppression studies indicated that 201Tl is taken up into the tumor cells partly through Na+, K+-ATPase of their membranes. Ionic radii of alkaline metals and thallium were related to their blood and tumor retention values. This relationship suggested that monovalent cations whose ionic radii exceed 0.133 nm, and which exist as free ions in the tissue fluids, behave like the potassium ion. Potassium and K analogs (Tl, Rb, Cs) are avidly taken up into viable tumor cells whose Na+, K+, ATPase activity is elevated. Therefore, suitable radionuclides of K and K analogs can be excellent agents for visualization of viable tumor tissues. (orig.)

  2. Clinical evaluation of myocardial SPECT using 99mTc-tetrofosmin (PPN 1011) in patients with ischemic heart disease

    International Nuclear Information System (INIS)

    Myocardial SPECT was performed in seven patients with ischemic disease using 99mTc-tetrofosmin (PPN 1011) and 201Tl. A comparison of findings between 99mTc-tatrofosmin and 201Tl on each segment by segmental analysis showed concordance in 70% of total segments and showed discordance in 45% of posterior-inferior segments. Positive predictive value of 99mTc-tetrofosmin was superior to that of 201Tl in the infero-posterior segments. 99mTc-Tetrofosmin was considered to be a useful agent for evaluation of myocardial perfusion in the ischemic heart disease, especially in infero-posterior myocardial wall of the left ventricle. (author)

  3. Effect of eating on thallium myocardial imaging

    International Nuclear Information System (INIS)

    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

  4. Sex-specific criteria for interpretation of thallium-201 myocardial uptake and washout studies

    International Nuclear Information System (INIS)

    A study was undertaken to determine the effect of gender on criteria for the quantitative analysis of exercise-redistribution 201Tl myocardial scintigraphy. The studies of 26 normal females and 23 normal males were subjected to bilinear interpolative background subtraction and horizontal profile analysis. Significant sexual differences were found in both regional uptake ratios and washout rates. These differences primarily reflected a proportionately decreased anterior and upper septal uptake in females, and faster washout in females. Faster myocardial 201Tl washout rates in females could not be clearly ascribed to either a physiological or artifactual explanation. It is concluded that since important differences exist between males and females in the detected pattern of 201Tl myocardial uptake and washout, sex-specific criteria may enhance the predictive accuracy of exercise-redistribution 201Tl myocardial scintigraphy

  5. Thallium-201 myocardial SPECT findings at rest in sarcoidosis

    International Nuclear Information System (INIS)

    In 41 patients with sarcoidosis (diagnosed according to criteria recommended by the Committee on Diffuse Pulmonary Disease, Ministry of Health and Welfare, Japan 1988), thallium-201 (201Tl) myocardial SPECT was performed to investigate: the ability of 201Tl SPECT to detect cardiac involvement of sarcoidosis with images recorded at rest and 2 hours later, and the relationships between 201Tl myocardial SPECT findings and the activity of sarcoidosis or endomyocardial biopsy findings. As to the abnormal findings in 201Tl myocardial SPECT, a low density area was seen in 13 of 41 cases (31.7%) and non-uniform uptake was found in 17 cases (41.5%), the mean washout ratio (n=39) was 16.5±7.4%, which is significantly lower than that found in normal subjects, 23.9±7.5% (n=10). Of the 19 patients judged visually to be normal, 5 patients had a reduced mean washout ratio less than 12%. Thus, the incidence of abnormal findings including all types of abnormality in sarcoidosis was 63.4% (26/41 cases). As measured by the serum ACE (angiotensin converting enzyme) or lysozyme level, or the presence of more than 30% symphocyte fraction in BALF (broncho-alveolar lavage fluid), 20 (80%) of 25 cases with 201Tl abnormality were judged to be active sarcoidosis, while only 6 (37.5%) of 16 cases with normal findings on 201Tl SPECT were judged to be active. This suggest that there is a significant relationship between the presence or absence of an abnormal finding on 201Tl myocardial SPECT and the activity of sarcoidosis. Among 13 patients examined by endomyocardial biopsy, 10 patients had abnormal findings on 201Tl myocardial SPECT and 7 of these 10 patients had no histological evidence of cardiac sarcoidosis. In all of these 7 patients, however, sarcoidosis was judged to be active. This suggest that endomyocardial biopsy is of limited value in the diagnosis of cardiac sarcoidosis. (author)

  6. 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

    International Nuclear Information System (INIS)

    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)

  7. Usefulness of 99mTc-methoxy-iso-butyl-isonitrile myocardial single photon emission computed tomography during infusion of low-dose dobutamine and nitroglycerin. Evaluation of myocardial viability

    International Nuclear Information System (INIS)

    This study evaluated myocardial viability with 99mTc-methoxy-iso-butyl-isonitrile (MIBI) single photon emission computed tomography (SPECT) during infusion of low-dose of dobutamine (DOB) and nitroglycerin (NTG). The subjects were 13 patients with coronary artery disease associated with wall motion abnormalities. Myocardial SPECT with MIBI was performed during infusion of NTG followed by infusion of DOB. Rest MIBI study was also performed on a separate day. The regional uptake of MIBI was visually evaluated by scoring (from 0=normal to 3=defect) in 9 regions of left ventricular wall in comparison with LVG or echocardiography data. The regional uptake of MIBI was quantitatively evaluated in 33 segments of left ventricular wall by a computer. The uptake of MIBI during infusion of both DOB and NTG was compared with that at rest study in the region of wall motion abnormalities. The mean uptake score of MIBI during infusion of both DOB and NTG and that of MIBI at rest was 1.8 and 2.1, respectively. The uptake of MIBI was significantly improved by infusion of both DOB and NTG (p<0.01). Percent of the peak activity of MIBI during infusion of both DOB and NTG and that of MIBI at rest in the region where the uptake score had been improved was 76.6±12.7% versus 74.0±13.1% (p<0.01). Percent of the peak activity of MIBI in the region where the uptake score had not been improved was 60.1±18.1% versus 60.7±18.7% (NS). Quantitative study also showed a significant improvement of MIBI uptake on the study of DOB and NTG. These results suggest that MIBI SPECT during infusion of both DOB and NTG infusion might be useful for evaluating myocardial viability. (S.Y.)

  8. Usefulness of thallium-201 single photon emission computed tomography to quantify the malignancy grade of brain tumors

    International Nuclear Information System (INIS)

    Preoperative thallium-201 (201Tl) single photon emission computed tomography (SPECT) was used to evaluate the histological malignancy in 24 patients with brain tumors. A corrected L/E ratio was calculated based on the ratio of thallium uptake in the tumor on early images versus the tumor in the delayed images (L/E ratio) corrected for thallium uptake in the contralateral cerebral hemisphere. The corrected L/E ratio in benign brain tumors was 0.79±0.23, significantly different to 1.32±0.25 in high grade astrocytomas (p201Tl SPECT using the corrected L/E ratio is effective for determining the malignant viability of tumors. (author)

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

    International Nuclear Information System (INIS)

    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

  10. Single photon quantum cryptography

    CERN Document Server

    Beveratos, A; Gacoin, T; Villing, A; Poizat, J P; Grangier, P; Beveratos, Alexios; Brouri, Rosa; Gacoin, Thierry; Villing, Andre; 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 an equivalent system based on attenuated light pulses.

  11. Single photon quantum cryptography.

    Science.gov (United States)

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

    2002-10-28

    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 color center in a diamond nanocrystal. The quantum bit error rate is less that 4.6% and the secure bit rate is 7700 bits/s. The overall performances of our system reaches a domain where single photons have a measurable advantage over an equivalent system based on attenuated light pulses. PMID:12398636

  12. The value of gallium-67 and thallium-201 whole-body and single-photon emission tomography images in dialysis-related {beta}{sub 2}-microglobulin amyloid

    Energy Technology Data Exchange (ETDEWEB)

    Yen Tzuchen; Tzen Kaiyuan [Dept. of Nuclear Medicine, Chang Gung Memorial Hospital, Taipei Medical Center and School of Medicine, Chang Gung University (Taiwan); Chen Kuosu; Tsai Chijuen [Dept. of Nephrology, Chang Gung Memorial Hospital at Keelung (Taiwan)

    2000-01-01

    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 {beta}{sub 2}-microglobulin amyloid ({beta}{sub 2}-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, {sup 67}Ga and {sup 201}Tl whole-body and SPET images were then acquired. If any {sup 67}Ga and/or {sup 201}Tl uptake was observed, a CT-guided biopsy was done. In those patients who had articular and/or peri-articular uptake of {sup 99m}Tc MDP, {sup 67}Ga and/or {sup 201}Tl and who were pathologically proven to have {beta}{sub 2}-MA, {sup 99m}Tc MDP, {sup 67}Ga and {sup 201}Tl 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 {sup 99m}Tc MDP uptake. Among these eight, six had intense {sup 99m}Tc MDP, {sup 67}Ga and {sup 201}Tl 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 {sup 67}Ga and {sup 201}Tl scans but less obvious changes in uptake of {sup 99m}Tc-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 {sup 67}Ga and {sup 201}Tl 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 {sup 99m}Tc-MDP whole-body bone scan can both detect active and pre-existing inactive deposits of {beta}{sub 2}-MA. {sup 67}Ga and {sup 201}Tl scans are helpful to differentiate active from inactive deposits of {beta}{sub 2}-MA and to evaluate the therapeutic effect on these patients. SPET images are usually needed to distinguish articular and peri-articular lesions from bone lesions. (orig.)

  13. The value of gallium-67 and thallium-201 whole-body and single-photon emission tomography images in dialysis-related ?2-microglobulin amyloid

    International Nuclear Information System (INIS)

    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 ?2-microglobulin amyloid (?2-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 ?2-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 ?2-MA. 67Ga and 201Tl scans are helpful to differentiate active from inactive deposits of ?2-MA and to evaluate the therapeutic effect on these patients. SPET images are usually needed to distinguish articular and peri-articular lesions from bone lesions. (orig.)

  14. Removal of {sup 99m}Tc and {sup 201}Tl by means of Lemna Gibba; Remocion de {sup 99m}Tc y {sup 201}Tl mediante Lemna Gibba

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez R, E.; Carreno de L, M. C.; Cuevas S, J. C.; Hernadez T, U. O. [Instituto Tecnologico de Toluca, Av. Tecnologico s/n, Fraccionamiento La Virgen, 52149 Metepec, Estado de Mexico (Mexico); Monroy G, F., E-mail: edelmiraf@yahoo.com [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2012-10-15

    In this work the capacity of the water macrophyte Lemna gibba coming from San Pedro Tultepec in the Mexico State was studied to remove the radioisotopes {sup 99m}Tc and {sup 201}Tl, in order to show the capacity of this macrophyte for to treat some radioactive waste flowing that could contain this radioisotopes type. The removal capacity of {sup 99m}Tc and {sup 201}Tl of the macrophyte Lemna gibba was determined using the batch method. In accordance with the values of the obtained K{sub d}, the Lemna gibba with a size of particle diameter among 1mm - 300 {mu}m presents a better adsorption of {sup 99m}Tc. The {sup 201}Tl is adsorbed better in the bioadsorbent when it has a size of particle diameter <150{mu}m. (Author)

  15. Regional wall thickening in gated myocardial perfusion SPECT in a Japanese population: effect of sex, radiotracer, rotation angles and frame rates

    International Nuclear Information System (INIS)

    Gated single-photon emission computed tomography (SPECT) imaging of myocardium by 99mTc and 201Tl is used extensively to measure quantitative cardiac functional parameters. However, factors affecting normal values for myocardial functional parameters and population-specific standards have not yet been established. The aim of the study was to determine the effect of sex, radiotracer, rotation angles and frame rates on resting myocardial wall thickening (WT) and to develop a Japanese standard of normal values for WT. Data from a total of 202 patients with low possibility of having cardiac problems were collected from nine hospitals throughout Japan. Patients were divided into five groups according to study protocol, and WT was evaluated according to the 17-segment and four-region (basal, mid and apical regions and the apex) polar map distribution. WT was generally higher in women than in men irrespective of the use of radiotracers, rotation angles or frame rates, and the difference was highly significant in the mid and apical regions. In any protocol used, resting myocardial thickening in the apex was higher than in the mid and apical regions, and thickening was lowest in the basal region, suggesting heterogeneous regional myocardial thickening (%) in normal subjects. Different rotation angles showed no significant change on WT, but different frame rates and tracers showed significant WT change in both sexes. Percent thickening of the myocardium was significantly higher in imaging by 99mTc-labelled tracers than in 201Tl. Sex, radiotracers and frame rates had a significant effect on myocardial thickening, and the importance of population-specific standards should be emphasized. A normal database can serve as a standard for gated SPECT evaluation of myocardial thickening in a Japanese population and might be applicable to Asian populations having a similar physique. (orig.)

  16. 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

    International Nuclear Information System (INIS)

    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)

  17. Assessment of vascularity and permeability in brain tumor using SPECT and 99mTc-DTPA-human serum albumin in relation to 201Tl SPECT

    International Nuclear Information System (INIS)

    Single photon emission computed tomography (SPECT) using technetium-99m-DTPA-human serum albumin (99mTc-HSA-D) and thallium-201 chloride (201Tl) was simultaneously performed on 25 patients with brain tumors; 10 with brain metastasis, 8 with astrocytoma (Gr. 3) and 7 with meningioma. The early image was obtained 10 minutes after 99mTc-HSA-D (740 MBq) injection, and the delayed image was taken 5 hours after the injection. HSA-D index, based on the ratio of 99mTc-HSA-D uptake in the tumor versus the cortical area, was calculated on each image, and compared with Tl index (tumor/contralateral cerebrum ratio). HSA-D delayed index was significantly greater than HSA-D early index in all tumor types (p<0.05 by the Wilcoxon ranked sign test). Linear correlation between HSA-D early index and HSA-D delayed index was significant in astrocytoma (GR. 3) (p<0.01) and meningioma (p<0.001), and a linear correlation between HSA-D delayed index and Tl index was significant in astrocytoma (Gr. 3) (p<0.05). It is concluded that HSA-D early index and delayed index could reflect tumor vascularity and permeability, respectively, and provide supplementary information for Tl index. (author)

  18. Discrimination capabilities of fine- needle aspiration combined with serum thyroglobulin and 201Tl scintigraphy of thyroid nodules

    International Nuclear Information System (INIS)

    The sensitivity and N.P.V. by 201Tl scintigraphy which nodular uptake was higher and equal to normal thyroid tissue on early scan without quantitative washout were higher than those of FNA combined with the serum thyroglobulin level (sensitivity; 96.9%, 53.1-75.0%, N.P.V. 96.3%, 72.2-80.5%, respectively p201Tl scintigraphy is more useful for discrimination of benign and malignant thyroid nodules than fine- needle aspiration combined with serum thyroglobulin. (author)

  19. Sequential change of SPECT using 201Tl chloride during the treatment of intracranial gliomas

    International Nuclear Information System (INIS)

    The authors followed up the change in SPECT using 201Tl chloride (Tl-SPECT) according to the course of treatment of intracranial gliomas and analyzed the difference in Tl-SPECT between the stable and progressive groups. The subjects were 26 series of supratentorial gliomas subjected to Tl-SPECT before and after the treatment (radiotherapy and chemotherapy). They were put on Tl-SPECT after 10 minutes (early image) and 4 hours (delayed) following intravenous injection of 74 MBq of 201Tl. Besides, RI count ratio (L/N) in the tumor lesion (L) to the contralateral parenchyma (N) was measured. The patients were divided into stable and progressive groups judging from the therapeutic efficacy. The change in L/N ratio before and after the treatment was analysed. The stable group showed a significant post-treatment decrease in L/N ratio compared with a significant post-treatment increase for the progressive group. This suggested that Tl-SPECT would change according to the course of treatment and aid in the therapeutic judgement in gliomas. (author)

  20. Computer simulation of temperature distribution on a solid target for 201Tl production

    International Nuclear Information System (INIS)

    Thallium-201 is of great interest in nuclear medicine for diagnostic purposes. It is produced by the 203Tl(p,3n)201Pb nuclear reaction. Since the target for 201Tl production is a solid target and the maximum beam current for the irradiation has a direct relation with its temperature surface, therefore, the control of temperature during the irradiation is essential. Designing a proper cooling system is one of the important and determining parameters in radionuclide production efficiency. Non-controlled temperature would cause melting and consequently loss of target materials that could be very costly especially when an isotopically enriched material is used. In this study, the heat transfer and temperature distribution on the target has been simulated based on a computational fluid dynamics (CDF) code for the thermal behavior of the target during the irradiation and under the different beam currents, cooling flow rates and target designing. The results on the routinely used target for the production of 201Tl in AMIRS, showed that there was a good linearity between proton beam currents (in the range of 100-350 ?A) and maximum temperature on the thallium target (345-458 K). The results also showed that the flow rate of the cooling water can be brought down (from routinely used 45 L/min) to 15 L/min without any risk of melting of target material. (authors)

  1. Diagnosis of right ventricular myocardial infarction by nuclear medicine

    International Nuclear Information System (INIS)

    Gated blood pool scintigraphy with sup(99m)Tc-RBC and exercise 201Tl-myocardial scintigraphy were performed in 4 patients with right ventricular myocardial infarction diagnosed by myocardial scars at bypass surgery, or Swan-Ganz catheterization and echocardiography. Exercise 201Tl-myocardial scintigraphy performed in 2 patients failed to reveal the right ventricle at exercise. Phase analysis and cinematographic display by gated blood pool scintigraphy revealed the disturbance in the movement of the right ventricular inferior wall in all cases. Therefore, this method is considered valuable in the diagnosis of the right ventricular infarction. (Namekawa, K.)

  2. Single-photon imaging

    International Nuclear Information System (INIS)

    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.)

  3. Delayed redistribution in thallium 201 SPECT myocardial perfusion studies

    International Nuclear Information System (INIS)

    Stress 201Tl myocardial perfusion studies are useful in differentiating viable, reversibly ischemic from infarcted myocardium. A perfusion defect that shows redistribution 2 to 4 h after 201Tl injection is diagnostic of ischemia, while a fixed defect suggests infarction. However, occasional patients with a fixed defect at 4 h have redistribution at 24 h. This study evaluates the frequency and significance of this delayed redistribution with SPECT 201Tl. Patients with either no or incomplete redistribution at 4 h had repeat imaging 18 to 48 h later. Delayed redistribution was seen in 8/26 (31 percent). Four had incomplete and four had no redistribution at 4 h. Delayed redistribution with SPECT 201Tl is more common than generally appreciated, and we recommend delayed images in patients with fixed perfusion defects or incomplete redistribution at 4-h imaging, particularly in patients with previous infarctions for whom a revascularization procedure is being considered

  4. Utilidad de la tomografía computarizada de emisión de fotón único sincronizada con el electrocardiograma para la detección de isquemia miocárdica silente en diabéticos tipo 2 / Gated single photon emission computer tomography for the detection of silent myocardial ischemia

    Scientific Electronic Library Online (English)

    Yamilé, Peña Q; Marco Antonio, Coca P; Juan Felipe, Batista C; José, Fernández-Britto R; Rodobaldo, Quesada P; Andria, Peña C.

    2009-08-01

    Full Text Available [...] Abstract in english 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. Materi [...] al and methods: Electrocardiogram, stress test and gated-SPECT were performed on 102 type 2 diabetic patients aged 60 ± 8 years without cardiovascular symptoms. AH 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, specifity 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.

  5. Utilidad de la tomografía computarizada de emisión de fotón único sincronizada con el electrocardiograma para la detección de isquemia miocárdica silente en diabéticos tipo 2 Gated single photon emission computer tomography for the detection of silent myocardial ischemia

    Directory of Open Access Journals (Sweden)

    Yamilé Peña Q

    2009-08-01

    Full Text Available 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. AH 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, specifity 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.

  6. 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

    International Nuclear Information System (INIS)

    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)

  7. 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

    Energy Technology Data Exchange (ETDEWEB)

    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)

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

    International Nuclear Information System (INIS)

    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 11.2?Sv/h ±2.3 and 43.1?Sv/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 2.7?Sv/h, and for 99mTc-MIBI was 18.1 and 9.8?Sv/h in a working day. (author)

  9. Evaluation of 99mTc-ECD SPECT for the detection of brain tumor. Comparison with 201Tl SPECT

    International Nuclear Information System (INIS)

    For the evaluation of brain tumor (n=15), we performed both dynamic and static 99mTc-ECD (ECD) SPECT studies. 201Tl SPECT was also used for comparison with the results of ECD SPECT. Dynamic ECD SPECT was obtained following the injection of 600 MBq of ECD. Five min after the injection of ECD, static ECD SPECT was performed. 201Tl SPECT was obtained 10 min after the injection of 74 MBq. Abnormal uptake was recognized in 7 of 15 tumors with dynamic ECD; 5 of 7 meningiomas, 1 of 1 glioblastoma and 1 of 1 astrocytoma. However, no abnormal uptake was seen in 3 of 3 benign tumors (1 low grade astrocytoma, 1 hemangioma, 1 craniopharyngioma) and in 2 of 2 brain metastases. In contrast abnormal uptake was seen in 11 of 15 tumors with 201Tl; 7 of 7 meningiomas, 2 of 2 brain metastases, 1 of 1 glioblastoma and 1 of 1 craniopharyngioma. No abnormal uptake was seen in 3 of 3 benign tumors (1 hemangioma and 2 low grade astrocytomas). Equivocal uptake was seen in 1 low grade astrocytoma with dynamic ECD and 201Tl. The mechanism of the accumulation of dynamic ECD to brain tumor is unclear. However, it may reflect not only blood flow, but also metabolism. (author)

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

    International Nuclear Information System (INIS)

    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 11.2?Sv/h ±2.3 and 43.1?Sv/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 2.7?Sv/h, and for 99mTc-MIBI was 18.1 and 9.8?Sv/h in a working day. (author)

  11. Simultaneous dual myocardial imaging with iodine-123-?-methyl iodophenyl-pentadecanoic acid (BMIPP) and thallium-201 in patients with coronary heart disease

    International Nuclear Information System (INIS)

    To assess the clinical value of simultaneous dual myocardial imaging with iodine-123-?-methyl-iodophenyl-pentadecanoic acid (123I-BMIPP) and thallium-201 (201TL), myocardial imaging was performed at rest and during execise in seven patients with coronary heart disease. When 123I-BMIPP and 201Tl images were compared, the initial exercise and resting images agreed 87% and 64%, respectively. In the initial resting images, the regional uptake of 123I-BMIPP was frequently less than that of 201Tl. The incidence of exercise-induced reversible defects by 201Tl in the Tl>BMIPP regions was significantly higher than that in the Tl=BMIPP regions (57% vs 4%, pBMIPP regions was also significantly higher than that in the Tl=BMIPP regions (91% vs 38%, pBMIPP) was found more frequently in regions with abnormal wall motion than in regions with normal wall motion (hypokinetic regions; 68%, severe hypokinetic or akinetic regions; 50%, vs normokinetic regions; 4%, p123I-BMIPP correlated closely with that of 201Tl in normal myocardium and the uptake of both 123I-BMIPP and 201Tl was severely reduced in myocardium with severe ischemia during exercise and prior infarction. These results indicate that dual myocardial imaging with 123I-BMIPP and 201Tl may provide a unique means of identifying patients with metabolically disturbed myocardium, such as hibernating and stunned myocardium. (author)

  12. Single photon emission computerized tomography

    International Nuclear Information System (INIS)

    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.)

  13. Single-photon sources

    International Nuclear Information System (INIS)

    The concept of the photon, central to Einstein's explanation of the photoelectric effect, is exactly 100 years old. Yet, while photons have been detected individually for more than 50 years, devices producing individual photons on demand have only appeared in the last few years. New concepts for single-photon sources, or 'photon guns', have originated from recent progress in the optical detection, characterization and manipulation of single quantum objects. Single emitters usually deliver photons one at a time. This so-called antibunching of emitted photons can arise from various mechanisms, but ensures that the probability of obtaining two or more photons at the same time remains negligible. We briefly recall basic concepts in quantum optics and discuss potential applications of single-photon states to optical processing of quantum information: cryptography, computing and communication. A photon gun's properties are significantly improved by coupling it to a resonant cavity mode, either in the Purcell or strong-coupling regimes. We briefly recall early production of single photons with atomic beams, and the operation principles of macroscopic parametric sources, which are used in an overwhelming majority of quantum-optical experiments. We then review the photophysical and spectroscopic properties and compare the advantages and weaknesses of various single nanometre-scale objects used as single-photon sources: atoms or ions in the gas phase and, in condensed matter, organic molecules, defect centres, semiconductor nanocrystals and heterostructures. As new generations of sources are developed, coupling to cavities and nano-fabrication techniques lead to improved characteristics, delivery rates and spectral ranges. Judging from the brisk pace of recent progress, we expect single photons to soon proceed from demonstrations to applications and to bring with them the first practical uses of quantum information

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

    International Nuclear Information System (INIS)

    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)

  15. A new classification of lung cancer from a nucleomedical viewpoint using quantitative 201Tl and 67Ga scans in relation to histological type

    International Nuclear Information System (INIS)

    The possibility of nucleomedically classifying lung cancer was studied with quantitative 201Tl and 67Ga scans. Fundamental experiments with phantoms were performed to correct 201Tl and 67Ga uptake by tumors, and a clinical study based on these experiments was carried out on 31 patients with lung cancer. The classification of lung cancer was impossible by measuring either 201Tl uptake or 67Ga uptake alone, but was possible by calculating the Crude Uptake Ratio (CUR), the ratio of 201Tl uptake to 67Ga uptake by tumors on the same patients. Fifteen adenocarcinomas had a high CUR of 1.45 +- 0.77, many of them taking up more 201Tl than 67Ga. Nine epidermoid carcinomas had a CUR of 0.34 +- 0.25, significantly lower than adenocarcinomas (p67Ga than 201Tl. Two adenosquamous carcinomas had a CUR of 0.95 +- 0.19, intermediate between adenocarcinomas and epidermoid carcinomas. CURs varied greatly ranging from 0.03 to 4.31 and the 31 patients showed a continuous arrangement from low-CUR epidermoid carcinoma to high-CUR adenocarcinoma. The measurement of 201Tl and 67Ga uptake by the tumors was found to enable not only the nucleomedical classification but the presumption of various histogeneses in lung cancer. (author)

  16. 201Tl SPECT for evaluation of brain tumors as compared with 123I-IMP SPECT and 18F-FDG PET

    International Nuclear Information System (INIS)

    Clinical usefulness of 201Tl SPECT for evaluation of brain tumors was studied in comparison with 123I-IMP SPECT and 18F-FDG PET. 201Tl SPECT and 123IMP SPECT were performed in 73 patients with brain neoplasm (group 1) and 15 patients with non-tumor cerebral diseases (group 2). Among them, 31 patients in group 1 and 5 patients in group 2 received 18F-FDG PET. SPECT was done with a ring type machine (HEADTOME SET011) and PET with a neuro PET (PCT H1). Forty-eight of 73 (65.8%) patients in group 1 showed increased accumulation of 201Tl in tumor site, whereas only 9 (12.3%) patients showed increased radioactivity of 123I-IMP in the lesion. Eighteen of 31 (58.1%) patients with neoplasm demonstrated increased regional cerebral metabolic rate of glucose (rCMRgl) in the lesion. Only two out of 15 (13.3%) patients with non-tumor lesion demonstrated increased accumulation of 201Tl. None of them showed accumulation of 123I-IMP or increased rCMRgl. Patients with malignant neoplasm demonstrated higher uptake of 201Tl in the lesion than those with benign neoplasm or non-tumor lesions. Post-therapeutic patients with glioblastoma or metastatic tumors showed lower 201Tl uptake than before therapy. Superimposed images of both 201Tl and 123I-IMP resemble rCMRgl functional images, suggesting increased 201Tl radioactivity in viable tumor tissue with decreased radioactivity in surrounding areas. 201Tl SPECT is useful for diagnosis of brain tumors and evaluation of effectiveness of therapy or evidence of residual tumor tissue. It may differentiate malignant tumors from benign tumors or non-tumor intracranial diseases including radiation injury and detect tumor recurrence earlier. (author)

  17. [Myocardial tissue vitality: clinical relevance, pathophysiology and identification].

    Science.gov (United States)

    Bax, J J; Cornel, J H; Poldermans, D; van Eck-Smit, B L; van der Wall, E E

    1998-01-10

    Heart failure is an increasing clinical problem because of the rising frequency of admissions and the high mortality. Excellent long-term results are obtained with heart transplantation, whereas the long-term prognosis is poor when patients are treated medically. It has recently been demonstrated that, in patients with depressed left ventricular (LV) function, revascularization may be an alternative form of therapy, since improvement of LV function, which is an important prognostic factor, may occur after coronary revascularization. Recovery of LV function after revascularization may occur in patients with dysfunctional but viable myocardium, whereas no recovery can be expected in patients with scar tissue. Improvement of LV function after revascularization can be explained on the basis of the concept of myocardial tissue vitality': chronically ischaemic myocardium temporarily loses the facility to contract, but the contraction is regained after revascularization (once the ischaemia is eliminated). For the selection of patients who may profit by a revascularization procedure, techniques have been developed for the identification of dysfunctional but viable tissue. The myocardial glucose metabolism can be visualized by administration of 18F desoxyglucose (FDG) and imaging by positron emission tomography or 'single photon emission computer tomography'. Vital tissue shows diminished perfusion with intact glucose metabolism (FDG perfusion mismatch); a vital tissue shows diminished perfusion without glucose metabolism (FDG perfusion match). Scintigraphy of the membrane of the myocardial cell can also be investigated using 201Tl scintigraphy. Reserve contractility of the myocardium can be visualized by echocardiography during administration of dobutamine. PMID:9556996

  18. Single-photon Optomechanics

    CERN Document Server

    Nunnenkamp, A; Girvin, S M

    2011-01-01

    Optomechanics experiments are rapidly approaching the regime where the radiation pressure of a single photon displaces the mechanical oscillator by more than its zero-point uncertainty. We show that in this limit the power spectrum has multiple sidebands and that the cavity response has several resonances in the resolved-sideband limit. Using master-equation simulations, we also study the crossover from the weak-coupling many-photon to the single-photon strong-coupling regime. Finally, we find non-Gaussian steady-states of the mechanical oscillator when multi-photon transitions are resonant. Our study provides the tools to detect and take advantage of this novel regime of optomechanics.

  19. Comparison of the myocardial uptake of a technetium-labeled isonitrile analogue and thallium

    International Nuclear Information System (INIS)

    The myocardial transmicrovascular transport of thallium-201 (201Tl) and technetium-99m hexakis(2-methoxyisobutylisonitrile) (MIBI) were compared during variable blood flow levels in nine blood-perfused, isolated rabbit hearts. Seventeen injections of radiolabeled albumin and EDTA as well as 201Tl and MIBI were performed by indicator-dilution techniques. When coronary flow was varied from 0.52 to 3.19 ml/g/min, myocardial extraction for MIBI averaged 0.38 +/- 0.09 (SD) whereas 201Tl myocardial extraction averaged 0.73 +/- 0.10 (p less than 0.001). Net extraction, which was calculated using end points of 1.8-4.9 minutes, averaged 0.41 +/- 0.15 for MIBI and was less than the 201Tl net extraction of 0.57 +/- 0.13 (p less than 0.001). The mean capillary permeability-surface area product for MIBI (0.44 +/- 0.13 ml/g/min) was one third of 201Tl (1.30 +/- 0.45 ml/g/min; p less than 0.001). However, parenchymal cell permeability-surface area product for MIBI (47.58 +/- 25.85 ml/g/min) was much higher than 201Tl (6.52 +/- 6.51 ml/g/min; p less than 0.0001), and apparent cellular volume of distribution for MIBI (15.15 +/- 3.31 ml/g) was also higher than 201Tl (10.19 +/- 4.00 ml/g; p less than 0.01). These data suggest that capillary permeability for 201Tl is greater than MIBI, but the reverse is true at the parenchymal cell wall. In addition, a new blood-perfused preparation is used for indicator-dilution techniques, and previously developed modeling analyses are also extended to these experiments

  20. Indistinguishability of independent single photons

    OpenAIRE

    Sun, F. W.; Wong, C W

    2008-01-01

    The indistinguishability of independent single photons is presented by decomposing the single photon pulse into the mixed state of different transform limited pulses. The entanglement between single photons and outer environment or other photons induces the distribution of the center frequencies of those transform limited pulses and makes photons distinguishable. Only the single photons with the same transform limited form are indistinguishable. In details, the indistinguish...

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

    Directory of Open Access Journals (Sweden)

    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

  2. Improved Diagnostic Performance of Thallium-201 Myocardial Perfusion Scintigraphy in Coronary Artery Disease: from Planar to Single Photon Emission Computed Tomography Imaging

    Directory of Open Access Journals (Sweden)

    Ming-Fong Tsai

    2002-08-01

    Full Text Available Background: This study was performed to compare Tl-201 myocardial perfusion singlephoton emission computed tomography (SPECT with planar scintigraphy inthe diagnosis of coronary artery disease (CAD.Methods: Retrospectively, 240 of 3262 patients, with exercise-redistribution Tl-201myocardial perfusion scintigraphy performed between January 1990 andOctober 1997, were analyzed to compare Tl-201 scintigraphy and coronaryarteriography. Within 30 days, all 240 patients underwent both coronaryarteriography and exercise-redistribution Tl-201 myocardial perfusionscintigraphy with 86 SPECT and 154 planar images acquired.Results: The sensitivities of Tl-201 myocardial perfusion scintigraphy in individualcoronary arteries including left anterior descending (LAD artery, left circumflex(LCX artery, and right coronary artery (RCA, were 77%/72%,31%/30%, and 77%/50% in the SPECT/planar study groups, respectively.The sensitivities of CAD detection in patients with single-vessel, double-vessel,and triple-vessel diseases were 96%/82%, 91%/85%, and 96%/90% inthe SPECT/planar study groups, respectively.Conclusion: SPECT images provide greater advantages over planar images for betterdetection of the number, location, and extent of CAD. Cardiac SPECT doesimprove the accurate interpretation in abnormal Tl-201 distributions due tothe higher contrast resolution and better separation of overlapping myocardialregions.

  3. Localisation of enlarged parathyroid glands: 201Tl-sup(99m)Tc subtraction scintigraphy compared with 5 MHz sonography

    International Nuclear Information System (INIS)

    Fifty patients clinically suspected of having primary hyperparathyroidism were examined by scintigraphy (201Tl-sup(99m)Tc subtraction) and sonography (5 MHz). In 28 cases, the results of subtraction scintigraphy, and in 26 cases, the results of sonography were checked by operation. In 25 patients there was a solitary parathyroid adenoma and in two, primary hyperplasia. In one patient all four parathyroid glands were normal. Subtraction scintigraphy had a sensitivity of 90% and a specificity of 98%, while sonography had a sensitivity of 82% and a specificity of 95%. The combination of 201Tl-sup(99m)Tc subtraction scintigraphy as a functional investigation and sonography as a structural imaging method produced a sensitivity of 96% and is therefore superior to all other methods of localisation for normally situated glands. Diagnostic certainty is reduced by the presence of a nodular thyroid. (orig.)

  4. 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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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.)

  7. Feasibility of simultaneous dual-isotope myocardial perfusion acquisition using a lower dose of sestamibi

    International Nuclear Information System (INIS)

    The feasibility of simultaneous dual-isotope myocardial perfusion imaging was assessed using a ca. 12 mCi dose of technetium-99m sestamibi (MIBI) and ca. 3 mCi thallium-201. Planar and single-photon emission tomographic (SPET) data from 40 patients (41 studies) imaged with both a single- and a dual-isotope protocol were analyzed. Rest injected 201Tl (pure-Tl) images were acquired using 20% windows at 70 and 166 keV about 15 min after the 201Tl injection. Patients were then stressed, and at peak stress 99mTc-sestamibi was injected. About 30 min later 99mTc data were recorded with a 20% window center at 140 keV, and simultaneous 201Tl (dual-Tl) data were recorded with a single 20% window centered at 80 keV. Total myocardial counts based on SPET data in the dual-T1 images were increased by 18.61%±2.91% (SEM) (range: -12.8% to 84.1%) compared to pure-Tl images. Region of interest analysis revealed the greater increase in counts in the apical region and the least in the lateral wall. Pure Tl and dual-Tl images were visually evaluated for image quality (IQ) on a five-point scale (0=uncacceptable to 4=excellent). Dual-Tl IQ was lower than that of pure-Tl in 61% of cases, and similar in 37% (12% of the pure-Tl and 41% of the dual-Tl images fell into the 0 and 1 categories). Thallium perfusion abnormalities were of similar extent in 70% of segments, less severe in 18%, and more severe in 12%. There was an inverse correlation with patient weight, such that patients weighing more than 180 lbs had substantially worse images than those below this cutoff value. While dual-tracer images are of lower quality, they are interpretable if the patient is not severely overweight. (orig.)

  8. Single photons on demand

    International Nuclear Information System (INIS)

    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.)

  9. Iodine-123 phenylpentadecanoic acid: detection of acute myocardial infarction and injury in dogs using an iodinated fatty acid and single-photon emission tomography

    International Nuclear Information System (INIS)

    The ability of an iodinated fatty acid, iodine-123 phenylpentadecanoic acid (1-123 PPA), and single-photon emission computed tomography (SPECT) to detect myocardium injured by temporary or permanent coronary arterial occlusion was evaluated. In 5 control dogs, 11 dogs that underwent 90 to 120 minutes of fixed left anterior descending coronary artery (LAD) occlusion, and 8 dogs that underwent 90 minutes of temporary LAD occlusion and up to 90 minutes of reflow, 2 to 6 mCi of I-123 PPA were injected and the dogs were imaged with SPECT. Control dogs showed relatively uniform uptake and clearance of I-123 PPA in similar left ventricular (LV) regions. Dogs with permanent LAD occlusion were identified by computer algorithm as having regions of decreased I-123 PPA uptake in the infarct-related area and a reduced rate of I-123 PPA clearance (-9.4% in infarct sectors [washin], +3.7% in sectors adjacent to the area of infarction, and +15.4% in control LV sectors [p less than 0.01]). Dogs with temporary LAD occlusion and reperfusion had decreased clearance of I-123 PPA from the regions with infarction; I-123 PPA clearance was -5.2 +/- 16.4% in infarct sectors, 12.7 +/- 7.4% in periinfarct zones, and 30.4 +/- 12% in control LV regions. These data demonstrate that tomographic analysis of I-123 PPA uptake and clearance permits the relatively noninvasive detection of LV myocardium injured by permanent or temporary LAD occlusion and reperfusion

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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

  12. Cardiac functional mapping for thallium-201 myocardial perfusion, washout, wall motion and phase using single-photon emission computed tomography (SPECT)

    International Nuclear Information System (INIS)

    A method for three-dimensional functional mapping of Tl-201 myocardial uptake, washout, wall motion and phase was developed using SPECT. Each parameter was mapped using polar display in the same format. Normal values were determined in Tl-201 exercise study in 16 patients. Myocardial counts were lower in the septum and inferior wall and the difference of counts between anterior and inferior walls were greater in man compared with the perfusion pattern in woman. Washout was slower at septum and inferior wall in man, and slightly slower at inferior wall in woman. In gated blood-pool tomography, length-based and count-based Fourier analyses were applied to calculate the parameters of contraction and phase. The results of both Fourier analyses generally agreed; however, the area of abnormality was slightly different. Phase maps were useful for the assessment of asynergy as well as in patients with conduction disorders. These cardiac functional maps using SPECT were considered to be effective for the understanding of three-dimensional informations of cardiac function. (author)

  13. Value of 201Tl imaging in predicting therapeutic 131I uptake in patients with thyroglobulin-positive but 131I scan-negative differentiated thyroid carcinoma

    International Nuclear Information System (INIS)

    Background: Serum thyroglobulin assay and 131Iodine (1311) whole body scan are considered complementary in detecting malignant thyroid tissue or metastases. A large number of patients, however, are encountered presenting with scan-negative, thyroglobulin-positive differentiated thyroid carcinoma posing a dilemma in therapeutic management. One of the first alternative scanning agents to be employed is 201Thallium (201Tl). Recent studies have demonstrated its usefulness in identifying lesions that are not visualized with traditional 131I whole body scan. It is not clear, however, whether 201Tl scan helps in the decision-making for subsequent 131I therapy. This study was conducted to determine if 201Tl scan can predict therapeutic 131I uptake and to define the clinical role of 201Tl scanning in these patients. Methods and results: A total of 12 patients (20-63 y/o), 5 males and 7 females, underwent surgery for differentiated thyroid cancer and all had serum thyroglobulin values above 10 ng/ml and normal TPO autoantibodies. Pre-therapy 131I scan using 111 MBq (3mCi) of 131I were obtained. As required for inclusion, all patients had negative pre-therapy scan and negative TPO autoantibody results and underwent 20lTl scanning within 3 weeks. All patients were given 131I therapy (3.7-5.5 GBq or 100-150 mCi) between one to two months after 201Tl scanning. Within a week after therapy, all patients underwent whole body 1311 scanning. 201Tl imaging demonstrated thyroid remnants in 9 out of 12 patients having positive 201Tl scan but negative pre-therapy 1311 scan. However, only 2 of the positive 201Tl scans showed 131I uptake post-therapy (positive predictive value of 20%). None of the subjects presented with a negative 201Tl scan and a positive post-therapy 131I scan. Conclusion: Our study suggests that evidence of remnants or metastases on 201Tl scanning may be an inappropriate basis for the decision to proceed with 131I therapy. The role of 20lTl imaging in this subset of patients may be limited to localization of metastases for surgical excision or localized radiation therapy. (authors)

  14. A comparative study of 201Tl scintigraphy and three-phase bone scintigraphy following therapy in patients with bone and soft-tissue tumors

    International Nuclear Information System (INIS)

    The purpose of this study was to evaluate the usefulness of 201Tl scintigraphy in comparison with three-phase bone scintigraphy in the differentiation of residual/recurrent tumors from post-therapeutic changes, in patients previously treated for bone and soft-tissue tumors. Thirty-five 201Tl and three-phase bone scintigraphy scans were obtained for 30 patients with a history of bone or soft-tissue tumor who had undergone chemotherapy, radiation therapy, tumor resection, or a combination of these treatments. The planar 201Tl images were acquired 10 mins (early) and 2 hrs (delayed) after the intravenous injection of 111 MBq 201Tl-chloride. Three-phase bone scintigraphy was performed using 740 MBq 99mTc-HMDP at the same lesion site as for 201Tl imaging. The blood flow images were obtained every 10 sec for 2 mins and were immediately followed by the blood pool image after 5 mins. Three to 4 hrs later, bone images were obtained. 201Tl and three-phase bone scintigraphies were correlated with the histopathologic findings and/or clinical follow-up of more than 3 months. Of the 35 cases, 15 were free of disease and 20 had residual or recurrent tumors. Of the 20 residual or recurrent cases, all had true-positive 201Tl early and delayed scans, while bone scintigraphy was true-positive on the blood flow, blood pool and bone images in 16, 18 and 12 cases, respectively. 201Tl early and delayed images and 99mTc-HMDP blood flow and blood pool images were false-positive in one patient. The histology of this false-positive case showed the presence of lymph proliferative tissue. Although 201Tl uptake after treatment does not always indicate recurrence, 201Tl scintigraphy may still be more useful than three-phase bone scintigraphy in the follow-up of patients with bone and soft-tissue tumors following therapy. (author)

  15. Pathophysiology of technetium-99m stannous pyrophosphate and thallium-201 scintigraphy of acute anterior myocardial infarcts in dogs

    International Nuclear Information System (INIS)

    In 17 dogs with acute myocardial infarcts produced by ligation of the proximal left anterior descending coronary artery, a comparative study was made of myocardial scintigrams obtained with technetium-99m stannous pyrophosphate (/sup 99m/Tc-PYP) and thallium-201 (201Tl), tissue levels of /sup 99m/Tc-PYP and 201Tl uptake, histopathologic alterations, and regional myocardial perfusion measured with radioactive microspheres. Nine of the 10 hearts examined histologically had transmural infarcts with outer peripheral, inner peripheral, and central zones characterized by distinctive histopathologic features. A progressive reduction in myocardial blood flow was demonstrated between normal myocardium and the centers of the infarcts, and correlated well with progressive reduction in 201Tl uptake in the same regions. Marked /sup 99m/Tc-PYP concentration occurred in areas with partial to homogeneous myocardial necrosis and residual perfusion located in the outer peripheral regions of the infarcts. The latter areas also were characterized by the presence of muscle cell calcification. The patterns of distribution of /sup 99m/Tc-PYP and 201Tl explained the filling defects on 201Tl myocardial scintigrams and the doughnut patterns on /sup 99m/Tc-PYP myocardial scintigrams in dogs with transmural infarcts. One dog with a subendocardial infarct had a small homogeneous area of activity on the /sup 99m/Tc-PYP myocardial scintigram; and showed marked uptake of /sup 99m/Tc-PYP in subendocardial areas of extensive necrosis and calcification still receiving some coronary perfusion. Thus, the data indicate that the status of regional myocardial perfusion is a key determinant for the occurrence of distinctive patterns of myocardial necrosis and for the scintigraphic detection of acute myocardial infarcts with /sup 99m/Tc-PYP and 201Tl

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

    International Nuclear Information System (INIS)

    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

  17. Assessment of the effect of revascularization early after CABG using ECG-gated perfusion single-photon emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kubo, Shigeto; Tadamura, Eiji; Kudoh, Takashi; Inubushi, Masayuki; Konishi, Junji [Dept. of Nuclear Medicine and Diagnostic Imaging, Kyoto University Graduate (Japan); Ikeda, Tadashi; Koshiji, Takaaki; Nishimura, Kazunobu; Komeda, Masashi [Dept. of Cardiovascular Surgery, Kyoto University (Japan); Tamaki, Nagara [Dept. of Nuclear Medicine, Hokkaido University, Sapporo (Japan)

    2001-02-01

    When an arterial graft is used, reversible perfusion defects on single-photon emission tomography (SPET) perfusion images are occasionally observed early after coronary artery bypass graft surgery (CABG), owing to the restricted flow capacity. The purpose of this study was to determine whether the functional information obtained with electrocardiography (ECG)-gated perfusion SPET could be helpful in evaluating the effect of revascularization early after CABG. Twenty-three patients (18 men and 5 women, mean age 65{+-}9 years) underwent stress/re-injection thallium-201 ECG-gated SPET before and 4 weeks after CABG (13 with exercise and 10 with dipyridamole). Patency of all grafts was confirmed by coronary angiography 1 month after CABG. Cardiac functional data including the left ventricular ejection fraction (LVEF) and the transient ischaemic dilatation (TID) ratio were analysed using a commercially available automated program. The conventional stress and re-injection tomograms were interpreted by means of a five-point scoring system in a nine-segment model. Stress-induced reversible {sup 201}Tl perfusion defects were present in 64% of the myocardial segments bypassed by patent arterial grafts, in contrast to 42% of the myocardial segments bypassed by patent venous grafts ({chi}{sup 2}=7.8, P=0.005). Of the 23 patients, 12 showed improvement in summed ischaemic scores (group 1), while 11 had no change or deterioration (group 2), although all grafts were patent on postoperative catheterization. The TID ratio improved in both group 1 and group 2 before and after CABG (1.14{+-}0.13 vs 0.99{+-}0.07, P=0.001 and 1.09{+-}0.07 vs 0.94{+-}0.05, P=0.002, respectively). However, LVEF did not significantly improve in group 1 or group 2 after CABG (42.5%{+-}9.9% vs 47.5%{+-}11.8%, and 52.1%{+-}7.5% vs 53.1%{+-}5.9%, respectively). Perfusion imaging or LVEF assessment is of limited value early after CABG. The TID ratio obtained with ECG-gated perfusion SPET may be a useful marker to evaluate the effect of revascularization early after surgery. (orig.)

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

    International Nuclear Information System (INIS)

    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

    International Nuclear Information System (INIS)

    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. Evaluation of bone and soft tissue lesion using 99mTc-MIBI. Comparison with 201Tl and the relation to chemotherapeutic effect

    International Nuclear Information System (INIS)

    Thirty-five patients with bone and soft tissue lesions were studied with 99mTc-MIBI and 201Tl to compare the uptake of two tracers. Planar images were obtained 15 min (early image) and 3 hr (delayed image) after the injection of both tracers. Images were evaluated visually and quantitatively using uptake ratio (lesion/background). In visual analysis, 23 of 35 patients showed similar uptake of both tracers, 9 showed more intense uptake of 99mTc-MIBI than 201Tl, and 3 showed more intense uptake of 201Tl than 99mTc-MIBI on early images. On delayed images, 21 of 32 patients showed similar uptake of both tracers, 3 showed more intense uptake of 99mTc-MIBI than 201Tl, and 8 showed more intense uptake of 201Tl than 99mTc-MIBI. In quantitative analysis, similar 201Tl and 99mTc-MIBI uptake ratios were obtained on early images. On delayed images, 99mTc-MIBI uptake ratios are less than that of 201Tl, but the difference was not significant. In some cases, 99mTc-MIBI accumulation was washed out on delayed images, therefore the early image is essential to evaluate 99mTc-MIBI accumulation. In all cases with the uptake ratios less than 1.20 on delayed 99mTc-MIBI images, chemotherapy was not effective. In malignant tumors, decreased uptake of 99mTc-MIBI accumulation on delayed images may indicate that chemotherapy is not effective. Delayed 99mTc-MIBI image may be a potential marker predicting chemotherapeutic effect in malignant bone and soft tissue tumors. (author)

  1. 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

    International Nuclear Information System (INIS)

    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 identification of viable myocardium, but delayed contrast enhanced MRI showed significant different pooled sensitivity in comparison to low-dose dobutamine stress echocardiography. (authors)

  2. Myocardial gated single photon emission tomography (GSPECT) in men and women with low probability of coronary artery disease - qualitative assessment of beating slices and polar plots

    International Nuclear Information System (INIS)

    Assessment of the variability of regional wall motion and thickening in men and women with normal left ventricular contraction and low probability of CAD by GSPECT. The rest 99mTcMyoview GSPECT protocol (700 Mbq) was performed in 28 women and 14 men. Qualitative beating slices - QLGS and polar plots - QGS were analyzed independently by scoring the colour scale (1 - severe impairment, 4 - normal). Then the regional wall motion and thickening in the anterior, lateral, inferior walls, the septum and apex were estimated. In all patients the motion in the inferior wall and septum assessed on polar maps were significantly different than one in QLGS but better in the apex. Regional wall thickening was underestimated in QGS polar plots in the anterior wall, septum, inferior and lateral wall. End diastolic and end systolic volumes were significantly greater in men (90±29, 69±25, p<0.02 and 40±20, 22±12, p<0.002 for EDV and ESV respectively). In the later group all walls except the inferior showed higher QGS thickening score in comparison to men. The motion score in the anterior wall was also significantly bigger (p<0.05). The visual regional motion and thickening assessment on beating slices in gated SPECT seems to be more reliable than polar plots in patients with normal left ventricular contraction and low probability of coronary artery disease. Gated SPECT polar maps show better myocardial thickening in women probably due to the smaller left ventricle size and subsequent partial volume effect. (author)

  3. The evaluation of cardiac function and the effect of therapy in acute myocardial infarction

    International Nuclear Information System (INIS)

    The cardiac function and the effect of therapy in patients with acute myocardial infarction (AMI) were assessed in over 100 patients by analysis of 201Tl-scintigraphy and 99mTc-gated pool study in our ICU. The cardiac function and 201Tl-defect ratio were compared with the results obtained in chronic phase. Sixteen of them were treated with intravenous urokinase (UK) within 6 hours from onset. The other 18 patients without UK treatment served as a control group. Significant correlation was recognized between 201Tl-defect ratio and peak-CPK levels, peak-GOT levels, peak-LDH levels. Significant correlation (r = -0.655, r = -0.713) were found between 201Tl-defect ratio and LVEF in acute and chronic phase. The UK group showed a significant increase of LVEF as compared with the control group in patients with antero-septal (A/S) AMI. In inferior (INF) AMI, no significant differences were observed UK and control group in LVEF, RVEF and 201Tl-defect ratio. In chronic phase, improvements of LVEF and 201Tl-defect ratio were observed in patients with A/S AMI. But no significant differences of LVEF, RVEF and 201Tl-defect ratio were observed in A/S AMI in acute and chronic phase. The UK group showed a significant increase of LVEF (50.1 %) as compared with the control group of A/S AMI in chronic phase. We have demonstrated that a combination of 201Tl-scintigraphy and 99mTc-gated pool study are useful techniques in ICU, to evaluate the cardiac function and the effect of thrombolysis therapy and thus greatly contribute to the primary care of AMI cases. (author)

  4. Diagnostic utility of myocardial imaging using 123I-labeled beta-methyl-iodophenyl pentadecanoic acid in ischemic heart disease

    International Nuclear Information System (INIS)

    We evaluated the myocardial metabolism in the acute subacute phases of myocardial infarction or unstable angina using 123I-labeled beta-methyl-iodophenyl pentadecanoic acid (BMIPP). We then compared those findings with (1) myocardial perfusion images obtained with 201TlCl and (2) the regional and global left ventricular function determined by left ventriculography. Thirty-one patients were examined, consisting of 16 with acute myocardial infarction (6.8±2.6 days after onset), 8 with subacute myocardial infarction (35±3.0 days after onset) and 7 with unstable angina. The BMIPP images showed a larger uptake-defect than 201TlCl images in the patients in the acute or subacute phase of myocardial infarction. This finding was especially remarkable in the acute phase after successful coronary revascularization therapy. Moreover, in such cases, the myocardial BMIPP uptake improved to the same degree as 201TlCl one month later. The decrease in myocardial uptake of BMIPP agreed well with the decrease in regional wall motion in the acute and subacute phases of myocardial infarction. In contrast, the myocardial perfusion of 201TlCl did not always agree with the regional wall motion in stunned or hybernating myocardium, where BMIPP showed an uptake-defect in the acute phase but improved in the subacute phase. Thus, BMIPP is surmised to be able to depict fatty acid metabolism in in vivo myocardial imaging. (author)

  5. Disease stage classification in hypertrophic cardiomyopathy by dual analysis of iodine-123-labeled metaiodobenzylguanidine and thallium-201 myocardial scintigraphies

    International Nuclear Information System (INIS)

    Many patients with hypertrophic cardiomyopathy (HCM) gradually changes from typical myocardial hypertrophy to dilated cardiomyopathy-like features. However, it is difficult to estimate the disease stage in HCM. To determine the disease stage, dual analysis of iodine-123-labeled metaiodobenzylguanidine (123I-MIBG) and thallium-201 (201Tl) myocardial scintigraphies were performed in 108 HCM patients. According to the scintigraphic distribution patterns, patients were divided into three groups. Group A (n=15): normal distributions of both 123I-MIBG and 201Tl, group B (n=71): normal 201Tl and low 123I-MIBG patterns, group C (n=22): low distributions of both scintigraphies. The decrease in 201Tl uptake was observed in only group C. Concerning 123I-MIBG, heart-to-mediastinum ratio (H/M) and washout rate (WOR) had good correlations with left ventricular systolic functions. H/M was decreased and WOR was increased in order of C, B and A groups. Left ventricular diastolic function reflected by isovolumic relaxation time was longer in group B than in group A. Attenuated left ventricular hypertrophy, enlarged left ventricular volumes, impaired left ventricular functions and serious clinical symptoms were observed in only group C. Myocardial sympathetic abnormalities in group B may be mainly due to myocardial hypertrophy, and those in group C may be due to myocardial injury. Dual analysis of 123I-MIBG and 201Tl scintigraphies may be useful to classify disease stages of HCM. (author)

  6. Study on different imaging time of late 201Tl thyroid imaging to differentiate malignant from benign thyroid nodules

    International Nuclear Information System (INIS)

    This study was undertaken to clarify better time to initiate the late 201Tl thyroid imaging to differentiate malignant thyroid nodules from benign ones. Thyroid images were obtained at 5 min, 1 and 3 hr after i.v. injection of 74 MBq of 201Tl chloride. The early (5 min) and late (1 or 3 hr) 201Tl images were compared in pathologically proven 38 malignant and 48 benign nodules of 83 patients. The lesion activity (LA) on the early image was visually graded as no uptake (-), slight uptake less than the surrounding thyroid tissue uptake (SITU) (±), uptake equal to the STTU (+), and uptake more than the STTU (++). The change of LA relative to the STTU from the early image to the late image was visually graded as decreasing (D), unchanged (U) or increasing (I) pattern when the LA was (±) to (++). The benign or malignant possibility at 1 hr and 3 hr in each lesion pattern was as follows: When the LA was (-) or D, the benign possibility was 95% (35/37) and 85% (39/46). When the LA was I, the malignant possibility was 96% (27/28) and 91% (21/23). When the LA is U, the diagnosis was equivocal: malignancy; 43% (9/21) at 1 hr and 59% (10/17) at 3 hr. The positive LA had a tendency to decrease with time irrespective of tumor character. The 1 hr image was statistically better than the 3 hr image as a late image. Comparative diagnosis of 5 min and 1 hr images with the criteria of I and U lesions being malignant and others being benign seems to be the best not to overlook malignant nodules: negative predictive value of 95% and sensitivity 95%. (author)

  7. Diagnostic value of early and delayed 201Tl thyroid scintigraphy in the evaluation of cold nodules for malignancy

    International Nuclear Information System (INIS)

    We performed 201Tl thyroid scintigraphy using an early and delayed scanning technique in 34 patients exhibiting cold nodules on sup(99m)Tc scans. Of the 29 benign nodules, 27 were correctly diagnosed as being negative, i.e. 93% specificity. However, two of five malignant nodules failed to concentrate activity on both the early and delayed scans. The low sensitivity (60%) of this method for detecting carcinomas limits its clinical value in the routine diagnostic work-up of patients with suspected thyroid cancer. Our findings are in contrast to previous more optimistic reports. (orig.)

  8. Myocardial uptake of thallium and rubidium during alterations in perfusion and oxygenation in isolated rabbit hearts

    International Nuclear Information System (INIS)

    The comparative effects of altered cellular function and coronary perfusion on myocardial 201Tl and 83Rb uptake were evaluated in three groups of isolated rabbit hearts having isovolumic contractions. Paired-indication dilution experiments were performed with 201Tl, 83Rb, and 111In-labeled albumin as an intravascular reference marker. In Group A hearts (n = 12), isotope transport was determined during control, hypoxia, and ischemia. In Group B hearts (n = 8), isotope transport was measured at control flow and again at a 50% and 80% reduction. In Group C hearts (n = 8) only 201Tl uptake was determined at control and following coronary reperfusion. Myocardial 201Tl and 83Rb transport were not significantly different and were proportional to flow. Although all interventions caused significant hemodynamic alterations, neither tracer was affected by hypoxia at constant flow. Thallium-201 permeation, however, was transiently decreased immediately after coronary reperfusion. We conclude that myocardial uptake of 201Tl and 83Rb are similar and directly related to flow, but do not reflect hypoxia induced cellular dysfunction

  9. Effect of attenuation correction on myocardial thallium-201 distribution in patients with a low likelihood of coronary artery disease

    International Nuclear Information System (INIS)

    Regional variation of tracer distribution is seen in uncorrected thallium-201 images of normal hearts. This study evaluates the effect of attenuation correction on myocardial 201Tl distribution in patients with low risk of coronary artery disease. An L-shaped dual-detector single-photon emission tomographic system equipped with a pair gadolinium-153 scanning line sources was used for sequential emission/transmission imaging in 36 patients (14 men and 22 women) with less than 5% risk for coronary artery disease. Uncorrected emission images were reconstructed using filtered backprojection (FBP) whereas the attenuation corrected (AC) images were iteratively reconstructed using the attenuation map computed form the transmission data. Both sets of images were reorientated into short axis, vertical long axis and horizontal long axis images. For quantification data were reconstructed into polar plots and count density estimated in 17 myocardial segments. The population % standard deviation for each segment of AC data was significantly smaller than that for FBP data, indicating improved homogeneity of tracer distribution. In men the anterior-basal inferior activity ratio improved from 1.20 for FBP to 0.96 for AC (stress) and from 1.23 for FBP to 0.98 for AC (delay) (P201Tl distribution in patients with low risk of coronary artery disease. An L-shaped dual-detector single-photon emission tomographic system equipped with a pair gadolinium-153 scanning line sources was used for sequential emission/transmission imaging in 36 patients (14 men and 22 women) with less than 5% risk for coronary artery disease. Uncorrected emission images were reconstructed using filtered backprojection (FBP) whereas the attenuation corrected (AC) images were iteratively reconstructed using the attenuation map computed form the transmission data. Both sets of images were reorientated into short axis, vertical long axis and horizontal long axis images. For quantification data were reconstructed into polar plots and count density estimated in 17 myocardial segments. The population % standard deviation for each segment of AC data was significantly smaller than that for FBP data, indicating improved homogeneity of tracer distribution. In men the anterior-basal inferior activity ratio improved from 1.20 for FBP to 0.96 for AC (stress) and from 1.23 for FBP to 0.98 for AC (delay) (P<0.0001). In women the anterior-basal inferior activity ratio changed from 1.08 for FBP to 0.94 for AC (stress) and from 1.08 for FBP to 0.93 for AC (delay) (P<0.001). The apex of AC images showed a d

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

    International Nuclear Information System (INIS)

    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

  11. Nanodiamond Emitters of Single Photons

    Directory of Open Access Journals (Sweden)

    Vlasov I.I.

    2015-01-01

    Full Text Available Luminescence properties of single color centers were studied in nanodiamonds of different origin. It was found that single photon emitters could be realized even in molecularsized diamond (less than 2 nm capable of housing stable luminescent center “silicon-vacancy.” First results on incorporation of single-photon emitters based on luminescent nanodiamonds in plasmonic nanoantennas to enhance the photon count rate and directionality, diminish the fluorescence decay time, and provide polarization selectivity are presented.

  12. Standardization and half-life of 201Tl by the 4?(x,e)-? coincidence method with liquid scintillation counting in the 4?-channel

    International Nuclear Information System (INIS)

    A high-quality solution of 201Tl has been standardized by the 4?(x,e)-? coincidence method in conjunction with efficiency extrapolation. Liquid scintillation was utilized for the detection of the X-rays and electrons in the 4?-channel. The accuracy of the technique was verified by submitting a standardized sample to the International Reference System (SIR) for comparison with activity results obtained from other methods. The decay of one of the sources was followed over a 2-week period by measuring the activity with this direct method on 91 occasions. The resulting 201Tl half-life was (3.0400 ± 0.0028) days. (Author)

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

    International Nuclear Information System (INIS)

    In the present work the procedure for the standardization of radionuclides using the 4?(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 4?(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 ?g 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)

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

    Science.gov (United States)

    Wu, Ming-Che; Tsai, Cheng-Ting; Lin, Hui-Chun; Sun, Fang-Ju; Lin, Ku-Hung

    2015-11-01

    We analyzed the left-ventricular functional data obtained by cardiac-gated single-photon emission computed tomography myocardial perfusion imaging (MPI) with thallium-201 (Tl-201) and technetium-99m-sestamibi (MIBI) protocols in different groups of patients, and compared the data between Tl-201 and MIBI. Two hundred and seventy-two patients undergoing dipyridamole stress/redistribution Tl-201 MPI and 563 patients undergoing 1-day rest/dipyridamole stress MIBI MPI were included. Higher mean stress ejection fraction (EF), rest EF, and change in EF (?EF) were noticed in the normal MPI groups by both Tl-201 and MIBI protocols. Higher mean EF was observed in the females with normal MPI results despite their higher mean age. Comparisons between the Tl-201 and MIBI groups suggested a significant difference in all functional parameters, except for the rest end diastolic volume/end systolic volume and ?EF between groups with negative MPI results. For the positive MPI groups, there was no significant difference in all parameters, except for the change in end diastolic volume and change in end systolic volume after stress between both protocols. The Tl-201 provides comparable left-ventricular functional data to MIBI cardiac-gated single-photon emission computed tomography in patients with positive MPI results, and may therefore be undertaken routinely for incremental functional information that is especially valuable to this patient group. PMID:26678935

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

    International Nuclear Information System (INIS)

    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)

  16. Single-photon decision maker

    CERN Document Server

    Naruse, Makoto; Drezet, Aurelien; Huant, Serge; Aono, Masashi; Hori, Hirokazu; Kim, Song-Ju

    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 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.

  17. Single-photon decision maker

    Science.gov (United States)

    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.

  18. Ramsey interference with single photons

    CERN Document Server

    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...

  19. Prognostic Contribution of Exercise Capacity, Heart Rate Recovery, Chronotropic Incompetence, and Myocardial Perfusion Single-Photon Emission Computerized Tomography in the Prediction of Cardiac Death and All-Cause Mortality.

    Science.gov (United States)

    Arbit, Boris; Azarbal, Babak; Hayes, Sean W; Gransar, Heidi; Germano, Guido; Friedman, John D; Thomson, Louise; Berman, Daniel S

    2015-12-01

    Chronotropic incompetence, measured by the percentage (%) of heart rate (HR) reserve achieved (%HR reserve), abnormal HR recovery, reduced exercise capacity (EC), and myocardial perfusion single-photon emission computerized tomography (SPECT MPS) abnormalities are known predictors of all-cause mortality (ACM) and cardiac death (CD). The aim of this study was to determine if EC, %HR reserve, and HR recovery add incremental value to MPS in the prediction of ACM and CD. A total of 11,218 patients without valvular disease and not on ? blockers underwent symptom-limited exercise MPS. %HR reserve was (peak HR - rest HR)/(220 - age - rest HR) × 100, with %HR reserve exercise was considered abnormal. Poor EC was defined as exercise duration ?6 minutes (7 metabolic equivalents). Summed stress scores (SSSs) were calculated using a 20-segment, 5-point MPS model. Statistical analysis was performed using Cox regression models. There were 445 deaths (148 CD) during a mean follow-up of 3.2 ± 2.5 years. In multivariate analysis, the independent predictors of ACM were age, ?(2) = 154.81; EC, ?(2) = 74.00; SSS, ?(2) = 32.99; %HR reserve, ?(2) = 24.74; abnormal electrocardiogram at rest, ?(2) = 23.13; HR recovery, ?(2) = 18.45; diabetes, ?(2) = 17.75; and previous coronary artery disease, ?(2) = 11.85 (p ?0.0006). The independent predictors of CD were SSS, ?(2) = 54.25; EC, ?(2) = 49.34; age, ?(2) = 46.45; abnormal electrocardiogram at rest, ?(2) = 30.60; previous coronary artery disease, ?(2) = 20.69; Duke treadmill score, ?(2) = 19.50; %HR reserve, ?(2) = 11.43; diabetes, ?(2) = 10.23 (all p ?0.0014); and HR recovery, ?(2) = 5.30 (p = 0.0214). The exercise variables showed increases in Harrell's C static and net improvement reclassification, with EC showing the strongest incremental improvement in predicting ACM and CD (respective C-index 76.5% and 83.3% and net reclassification index 0.3201 and 0.4996). In conclusion, EC, %HR reserve, and HR recovery are independent predictors of ACM and CD and add incremental prognostic value to extent and severity of MPS. PMID:26482180

  20. Attenuation-corrected thallium-201 single-photon emission tomography using a gadolinium-153 moving line source. Clinical value and the impact of attenuation correction on the extent and severity of perfusion abnormalities

    International Nuclear Information System (INIS)

    The aim of the study was to test the clinical value of attenuation-corrected (AC) thallium-201 single-photon emission tomography using a moving gadolinium-153 line source in a group of patients in whom coronary angiography was planned because of clinically suspected coronary artery disease (CAD). Furthermore, we wanted to test the impact of AC on assessment of the extent and severity of perfusion abnormalities. A total of 107 patients planned to undergo coronary angiography were included in the study. In each patient, AC and NC (non-corrected) 201Tl SPET was performed. AC and NC images were evaluated visually as well as by a 31-segment semiquantitative analysis and the findings were correlated with angiographic results. Patients were assigned to two groups: group A with angina and no previous cardiac infarction or intervention and group B with known CAD because of previous myocardial infarction or intervention. With visual analysis, NC revealed a sensitivity of 88.9% in group A and 74.3% in group B, compared to 94.4% in group A and 94.3% in group B with AC. Specificity for NC was calculated to be 68.7% for a group A and 91.3% for group B. AC demonstrated significantly higher specificity of 83.9% and 100%, respectively. This effect was particularly demonstrated for males and bicycle workload. The extent and severity of perfusion abnormalities were significantly influenced by the use of AC, in that significantly fewer abnormal and less severely abnormal segments were demonstrated in the segmental analysis as compared to NC; this was especially true for the vascular territory of the left anterior descending artery and the right coronary artery.(orig./MG)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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)

  3. Single photon searches at PEP

    Energy Technology Data Exchange (ETDEWEB)

    Hollebeek, R.

    1985-12-01

    The MAC and ASP searches for events with a single photon and no other observed particles are reviewed. New results on the number of neutrino generations and limits on selection, photino, squark and gluino masses from the ASP experiment are presented.

  4. Single photon searches at PEP

    International Nuclear Information System (INIS)

    The MAC and ASP searches for events with a single photon and no other observed particles are reviewed. New results on the number of neutrino generations and limits on selection, photino, squark and gluino masses from the ASP experiment are presented

  5. Investigation of the biokinetics of thallium-201 and technetium-99m-stannous-pyrophosphate by experimentally induced myocardial infarction of the cat

    International Nuclear Information System (INIS)

    The radionuclide distributions of the imaging agents 201Tl and sup(99m)Tc-Sn-PyP were studied in the infarcted heart of the cat. After 24 h. experimentally induced myocardial infarction, tracer concentrations of about 100 myocardial tissue samples taken from each heart were determined. The distribution patterns of the two radionuclides were compared. (author)

  6. Detection of coronary artery disease using 12-lead electrocardiogram and simultaneous dual myocardial imaging with iodine-123-?-methyl iodophenyl-pentadecanoic acid (BMIPP) and thallium-201 in patients with unstable angina

    International Nuclear Information System (INIS)

    We investigated the usefulness of 12-lead electrocardiogram and simultaneous single-photon emission computed tomography (SPECT) with 123I-?-methyl iodophenyl-pentadecanoic acid (BMIPP) and thallium-201 (201Tl) for detecting coronary artery disease (CAD) in 54 consecutive patients with unstable angina. Discordant BMIPP uptake was defined as less 123I-BMIPP uptake than 201Tl uptake in 123I-BMIPP/201Tl dual SPECT. In the detection of CAD, ischemic electrocardiographic change during anginal attack had high sensitivity and low specificity, while discordant BMIPP finding had low sensitivity and high specificity. In patients showing ST depression during anginal attack, discordant BMIPP uptake showed high sensitivity and high specificity for detecting CAD. In conclusion, both 12-lead electrocardiogram during anginal attack and discordant BMIPP uptake are useful in detecting CAD in patients with unstable angina. (author)

  7. Clinical significance of increased lung/heart ratio in 210Tl stress myocardial image

    International Nuclear Information System (INIS)

    230 cases were studied with 201Tl stress image. The results showed that the lung/heart ratio closely correlated with the presence and severity of coronary heart disease (CHD). Among them, 18 cases (7.8%) showed significantly elevated lung/heart ratio (> 0.50). It was confirmed that all of the 18 cases have severe CHD with left ventricular insufficiency. The author emphasizes that measurement of the lung/heart ratio during 201Tl stress myocardial image may be useful for the assessment of the severity, evalation of the left ventricular function and judgement of prognosis in CHD

  8. Teleportation using squeezed single photons

    OpenAIRE

    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.

  9. Relationship between thallium-201 myocardial SPECT and findings of endomyocardial biopsy specimens in dilated cardiomyopathy

    International Nuclear Information System (INIS)

    The purpose of this study was to clarify which myocardial histological findings associated with dilated cardiomyopathy (DCM) are reflected in quantitative 201Tl myocardial SPECT. We obtained studied SPECT images from 21 patients with DCM 10 minutes and 2 hours after they received an injection of 111 MBq 201Tl at rest. We calculated the percent coefficient of variation of myocardial 201Tl counts [%CV(Tl)], the washout rate (WR), standard deviation of WR [SD(WR)], extent score (ES) and severity score (SS). We used image analysis to measure % fibrosis, % myocytes, the ratio of fibrous tissue to myocyte tissue (F/My), myocyte size and standard deviation of myocyte size [SD(My)] in left ventricular endomyocardial biopsy specimens. The %CV(Tl) was correlated with % fibrosis and F/My. The ES and SS also correlated with F/My. The correlation between SD(WR) and SD(My) was significant. The present findings suggest that %CV(Tl), ES and SS of rest 201Tl SPECT reflect myocardial fibrosis and that the standard deviation of washout reflects the distribution of myocyte size. (author)

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    In a preliminary study, the delineation of myocardial infarctions using thallium-201 with a conventional gamma camera has been compared with the results obtained with a tomographic positron camera using rubidium-81. Six patients with documented myocardial infarcts were studied with both methods, collecting 300,000 counts per image. The four projections obtained sequentially with thallium required about 60 minutes. Four tomographic planes recorded simultaneously with positron system required about 20 minutes imaging time. The image quality was approximately the same for both systems, which demonstrated the lesions well. The positron system thus appears to be superior in performance and, in connection with digital methods, is capable of flexible extension to any number of simultaneous planes of focus and to reconstructive imaging

  12. 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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  13. Evaluation of primary lung cancer and mediastinal lymph node metastasis using 99mTc-MIBI. Comparison with 201Tl and relation to chemotherapeutic effect

    International Nuclear Information System (INIS)

    We compared the detectability of 99mTc-MIBI and 201Tl-chloride for primary lung cancer and mediastinal lymph node metastasis. We also analyzed the relationship between 99mTc-MIBI uptake and effectiveness of chemotherapy in patients with small cell lung cancer. The subjects were forty-six primary lesions and 8 mediastinal metastatic lymph nodes confirmed by operation, and dual-isotope SPECT technique was performed at both 20 min and 180 min after tracer injection. A tumor to normal lung ratio on both early (ER) and delayed image (DR) and retention index (RI) were calculated. The positive rates of 99mTc-MIBI(early; 82.6%, delayed; 54.3%) were comparable to 201Tl in most primary tumor (87.0% and 84.8%). Whereas tumor smaller than 3 cm diameter was poorly visualized on both 99mTc-MIBI (25% and 0%) and 201Tl and (37.5% and 37.5%). Detectabilities of metastatic mediastinal lymph nodes of 99mTc-MIBI (62.5% and 25.0%) was comparable to those of 201Tl (62.5% and 50.0%). Regarding effectiveness of chemotherapy, NC group showed lower uptake of 99mTc-MIBI and significant lower value of RI compared to PR group. We concluded that early image of 99mTc-MIBI SPECT can be helpful in detecting primary lung cancer and metastatic mediastinal lymph node. Additionally, it might be useful for predicting the effects of chemotherapy in small cell lung cancer. (author)

  14. Use of 99mTc-MIBI scintigraphy in the evaluation of the response to chemotherapy for osteosarcoma. Comparison with 201Tl scintigraphy and angiography

    International Nuclear Information System (INIS)

    In the treatment of osteosarcoma, the chemotherapeutic effect influences decisions regarding the surgical margin, continuation of chemotherapy, and choice of anticancer drugs for further chemotherapy. Therefore, it is necessary to evaluate the response to chemotherapy in the middle of the chemotherapy course. In this study, we investigated the use of 99mTc-hexakis-2-methoxyisobutyl-isonitrile (99mTc-MIBI) scintigraphy in evaluating the response to chemotherapy of patients with osteosarcoma in comparison with 201Tl scintigraphy and angiography. A total 45 patients with osteosarcoma were examined using 99mTc-MIBI scintigraphy, 201Tl scintigraphy, and angiography to evaluate their response to chemotherapy. The percentage reduction in the uptake ratios (?UR) calculated as 100 x [(prechemotherapy value - postchemotherapy value)/prechemotherapy value] were compared with histological assessments. Similarly, changes in tumor vascularity assessed by angiograms were compared with histological assessments. On the angiographic findings, the results were classified as complete response (CR), partial response (PR), no change (NC), or progressive disease (PD). On the images, ?UR in 99mTc-MIBI ?30% and ?UR in 201Tl ?30% were classified as responder, as were CR and PR in angiograms. The therapeutic effect was assessed by histopathological examination of the resected specimens. The tumors of poor responders showed less than 90% necrosis, whereas the tumors of good responders showed 90% or more necrosis. Sensitivity, specificity, and accuracy were 73.9, 84.2, and 78.6%, respectively, for 99mTc-MIBI (?=0.57); 80.0, 61.1, and 72.1%, respectively, for 201Tl (?=0.42); and 91.7, 35.0, and 65.9%, respectively for angiography (?=0.28). 99mTc-MIBI could be effectively used to predict the final response to chemotherapy of osteosarcoma. (author)

  15. ROC analysis of tumor detectability using 201Tl (I) chloride and 99mTc (I) hexakis (2-methoxy-2-isobutylisonitrile)

    International Nuclear Information System (INIS)

    We investigated tumor detectability of bronchial carcinoma using 201Tl and 99mTc-MIBI with planar scintigraphy and SPECT. We studied 30 tumor patients and 7 patients with coronary artery disease in a clinical phase III trial. The lung was partitioned into 6 areas, which were read independently, to provide a sufficiently large sample of tumor-free reference regions. We calculated the statistical power for the comparison of sensitivities at a given specificity of 95% (TPF-test) to demonstrate that the subdivision of the lung and the application of the bivariate binormal ROC model allows an objective assessment of diagnostic performance even for the small sample size of our study. There were no significant differences between 201Tl and 99mTc-MIBI for both observers; therefore, no advantage of 99mTc-MIBI over 201Tl for tumor scintigraphy could be demonstrated. SPECT was significantly superior to planar scintigraphy and sould be preferred for tumor detection in the thorax. (orig.)

  16. Defect images in stress thallium-201 myocardial scintigraphy in patients with complete left bundle branch block. Comparison of exercise stress and pharmacological stress

    International Nuclear Information System (INIS)

    Stress thallium-201 (201Tl) myocardial scintigraphy can demonstrate perfusion abnormalities, especially in the septum in patients with complete left bundle branch block (CLBBB) even with angiographically normal coronary arteries. Differences in the images between exercise and pharmacological stress 201Tl myocardial scintigraphy were evaluated in patients with CLBBB and normal coronary arteries. Forty-five patients with CLBBB underwent exercise stress using treadmill or pharmacological (adenosine triphosphate) stress 201Tl myocardial scintigraphy from October 1997 to February 2003. Patients with myocardial diseases were excluded, such as cardiomyopathy and coronary artery diseases detected by echocardiography and/or cardiac catheterization. The myocardial segment was classified according to the American Heart Association style for coronary artery disease. Peak blood pressure levels and heart rates were significantly higher in the exercise stress group than in the pharmacological stress group (p201Tl myocardial scintigraphy according to the stress method. Moreover, defects also occurred in areas other than the septum. Blood pressure and heart rate were involved in the mechanisms of defects in left bundle branch block. (author)

  17. Quantitative single photon emission tomography

    International Nuclear Information System (INIS)

    Single photon emission tomography (SPET) is using nuclear medicine methods to allow functional imaging of organs. This paper describes realization of a quantitative SPET visualization, which can be achieved if gamma photon attenuation and scattering are included in the image reconstruction process. Iterative image reconstruction procedures, necessary for quantitative imaging, require knowledge of projection matrix. For its determination an efficient and clinically applicable model is proposed; the model treats both attenuation (based on known attenuation map) and multiple scattering (using buildup factors). Obtained results are compared with those obtained by MC simulation (author)

  18. Myocardium scanning with 201TL-chloride in ischemic heart disease

    International Nuclear Information System (INIS)

    Results of myocardial scanning with 210TL-chloride in ischemic herart disease are repoorted. An avearge dose of 500 microcurie and antero-posterior or lateral projection scanning with coloured registration are recommended. The scintigraphic pattern of the normal myocardium and the pathological changes, manifested by reduced isotope fixation, depending on the severity of the damage, are described. The diffuse pathological changes in the myocardium in ischemic heart disease are manifested by diffuse hypofixation of the radionuclide. The focal lesions in ischemic heart disease were manifested by characteristic changes: the infarctions of the posterior wall show a relatively clear scanographic picture on antero-posterior projection, with cold or cool zones in the median sections of the myocardium picture. Infarctions of the anterior myocardial wall, depending on how sizable they are, on antero-posterior projection are seen to occupy the lateral and central parts of the heart muscle. In the left oblique projection the pathologic process is projected frontally and centrally. (A.B.)

  19. Usefulness of 201Tl chloride quantitative gated SPECT in patients with cardiac sarcoidosis

    International Nuclear Information System (INIS)

    To examine the usefulness of thallium-201 quantitative gated SPECT (QGS) in patients with cardiac sarcoidosis, thirteen patients with systemic sarcoidosis, were examined by thallium-201 QGS and echocardiography. They were divided into two groups, A and B, with or without cardiac involvement of sarcoidosis according to the Japanese Ministry of Health and Welfare guidelines for cardiac sarcoidosis. Distribution abnormality was detected both in group A and group B, suggesting cardiac involvement caused by sarcoidosis in both groups, and the unreliability of these guidelines. The left ventricular (LV) wall was divided into 5 segments. The overall agreement between thallium-201 QGS and echocardiography for regional wall motion assessment of the LV was 72% (44/65 segments) suggesting the reliability of thallium-201 QGS for regional wall motion measurement. Among 44 segments with distribution abnormality, 17 segments had wall motion abnormality. Distribution abnormality with wall motion abnormality may reflect irreversible myocardial damage such as scar-like lesion, whereas distribution abnormality without wall motion abnormality may reflect the inflammatory stage, which can respond to steroid therapy. Thallium-201 QGS plays an important role in the diagnosis and follow up of cardiac involvement in patients with sarcoidosis, since this method is noninvasive, can be performed repeatedly and is suitable for simultaneous assessment of regional/total function and myocardial damage of the left LV. (author)

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

    International Nuclear Information System (INIS)

    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)

  1. Application of nuclear medicine for acute myocardial infarction in critical care center

    International Nuclear Information System (INIS)

    To evaluate the acute myocardial infarction, we studied 180 201Tl myocardial scintigraphys and 73 99mTc-HMDP myocardial scintigraphys. In our center, 99mTc-HMDP positive rate was 75.2%. This data suggests the limitation of planar image, therefore its positive ratio of the small infarction group (peak CPK, less than 1000) was remarkably low. Otherwise in the thrombolysis therapy group, there was some discrepancy between 201Tl and 99mTc-HMDP images. In the reperfused group, the positive image of 99mTc-HMDP compatible with the Parkey's 0?2 grade and in the non-reperfused group, the Parker's 3?4 grade, corresponded the degree of myocardial ischemia. The right ventricular image was demonstrated in the collateral group in patients with acute inferior myocardial infarction. (author)

  2. Better Randomness with Single Photons

    CERN Document Server

    Oberreiter, Lukas

    2014-01-01

    Randomness is one of the most important resources in modern information science, since encryption founds upon the trust in random numbers. Since it is impossible to prove if an existing random bit string is truly random, it is relevant that they be generated in a trust worthy process. This requires specialized hardware for random numbers, for example a die or a tossed coin. But when all input parameters are known, their outcome might still be predicted. A quantum mechanical superposition allows for provably true random bit generation. In the past decade many quantum random number generators (QRNGs) were realized. A photonic implementation is described as a photon which impinges on a beam splitter, but such a protocol is rarely realized with non-classical light or anti-bunched single photons. Instead, laser sources or light emitting diodes are used. Here we analyze the difference in generating a true random bit string with a laser and with anti-bunched light. We show that a single photon source provides more r...

  3. Thallium-201 myocardial imaging in unstable angina and variant angina

    International Nuclear Information System (INIS)

    It is of clinical relevance in the coronary care unit to evaluate the potential role of 201Tl scintigraphy in patients with unstable angina. In the present chapter the authors discuss 1) the pattern of 201Tl scintigraphy in patients with unstable angina; and 2) the potential predictive value of 201Tl scintigraphy in identifying patients with unstable angina who have a poorer prognosis or greater tendency to subsequently develop acute myocardial infarction. All patients with unstable angina pectoris were purposely studied during the pain free period. It seemed conceivable that injecting 201Tl during an anginal attack would result in a high percentage of scintigraphic defects and probably diminish a potential discriminative value of the method. Moreover in clinical practice the majority of patients arrive at the coronary care unit some time after the last anginal attack. If a diagnostic test performed at this time could distinguish high and low risk patients, important therapeutic decisions might be made at the earliest possible times. (Auth.)

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

    International Nuclear Information System (INIS)

    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

  5. Comparison of myocardial imaging with iodine-123-iodophenyl-9-methyl pentadecanoic acid and thallium-201-chloride for assessment of patients with exercise-induced myocardial ischemia

    Energy Technology Data Exchange (ETDEWEB)

    Chouraqui, P.; Maddahi, J.; Henkin, R.; Karesh, S.M.; Galie, E.; Berman, D.S. (Cedars-Sinai Medical Center, Los Angeles, CA (USA))

    1991-03-01

    Iodine-123-iodophenyl-9-methyl-pentadecanoic acid (({sup 123}I)MPDA) and thallium-201 ({sup 201}Tl) were sequentially injected in 11 patients during exercise-induced myocardial ischemia. Simultaneous dual-energy planar images were obtained at 5 min, 3 and 5 hr. All studies were concordantly either positive (8/11) or negative (3/11) by both radionuclides. Exact agreement for segmental uptake was 93%, 94% and 94% for 5-min, 3- and 5-hr images, respectively. Exact agreement for defect reversibility by 3 and 5 hr were 95% and 92%. The initial defect contrasts and myocardial-to-lung ratios were similar by both agents but myocardial-to-liver ratio was lower by ({sup 123}I)MPDA at 5 min, which became similar to {sup 201}Tl at 5 hr. Normal percent myocardial clearances of both agents were comparable and significantly higher than those in defect zones. Thus ({sup 123}I)MPDA is suitable for myocardial imaging and correlates closely with {sup 201}Tl for initial postexercise myocardial uptake and defect reversibility. Defect reversibility appears to result from differential myocardial clearance from normal and ischemic regions.

  6. Single photon time resolution spectra

    International Nuclear Information System (INIS)

    Using the technology of the single photon time resolution, we have studied the time characters of light emission both in SQS mode and in G-M mode. The results show that the SQS streamer has a delay relative to the primary avalanche and its lasting time is about 10∼30 ns which depends on the contents of the quenching gas and the anode high voltage, and lasting time in the G-M mode is a few μs. It has fully demonstrated the SQS mode and G-M mode is a few μs. It has fully demonstrated the SQS mode and G-M mode are quite different each from other

  7. Spectral compression of single photons

    CERN Document Server

    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...

  8. Study on the assessment and improvement of diagnostic efficacy of myocardial scintigraphy for ischemic heart diseases

    International Nuclear Information System (INIS)

    In order to improve the diagnostic efficacy of two nuclides, sup(99m)technetium pyrophoshate (sup(99m)Tc-PYP) and thallium 201 (201Tl) in the diagnosis of coronary ischemic diseases, their quantitative evaluation and loading methods were studied, and the scintigrams with these nuclides were compared with coronary angiograms (CA). With sup(99m)Tc-PYP, 22 cases (5 normals and 17 patients with coronary heart diseases (CHD)) were examined through the myocardium/thoracic vertebra (M/Th) ratio. The positive M/Th ratio was more than 1.2 and the best imaging time was 60-90 minutes after injection. The specificity of the sup(99m)Tc-PYP scintigram correlated well with CA but its sensitivity did not. The 201Tl uptake with the 201Tl scintigram using the regional cardiac muscle blood flow method was examined in 61 patients with CHD. In comparison with CA, the specificity of the 201Tl scintigram was 97-100% and its sensitivity was 50%. By experimental studies it was found, by using the myocardium/liver ratio on 12 dogs and the isocount display method on 10 patients with angina pectoris, that the glucose-insulin tolerance method increased the 201Tl uptake in the myocardium. It can be concluded that the M/Th ratio is useful in the diagnosis of unstable angina, but the quantitative method of 201Tl is not adequate to use as a diagnostic device. From the metabolic point of view, the further study, such as using PET, is needed because these scintigrams clearly reflect not only the coronary blood flow but also the myocardial metabolism. (author)

  9. Caffeine reduces dipyridamole-induced myocardial ischemia

    International Nuclear Information System (INIS)

    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

  10. Single photon response of photomultiplier tubes

    International Nuclear Information System (INIS)

    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.)

  11. Thallium-201 uptake ratio correlated with myocardial mass ratio in chronically hypertrophied rat hearts induced by preferential pressure or volume overload

    International Nuclear Information System (INIS)

    Hemodynamic measurements, left to right myocardial ventricular mass ratio and myocardial thallium-201 (201Tl) uptake ratio were measured in 6 normal and the following 30 experimental rats (each group, n=6). Right ventricular (RV) pressure overload (PO) was induced by administration of monocrotaline. RV volume overload (VO) was induced by suturing a pulmonary valve to the pulmonary artery. Biventricular (BV) VO was induced by creation of an aortocaval fistula. Left ventricular (LV) PO was induced by constriction of the ascending aorta and LVVO was induced by destruction of the aortic valves. RV mass to body weight (BW) was significantly increased in RPVO, RVVO and BVVO models compared with the control. LV mass to BW was significantly increased in LVPO, LVVO models. RV peak systolic pressure (PSP) was significantly increased in RVPO, BVVO and LVVO models, and LVPSP was significantly increased in LVPO, BVVO and LVVO models. LV/RV mass ratio was significantly decreased in RVPO, RVVO and BVVO models, and was significantly increased in LVPO and LVVO models. LV/RV myocardial 201Tl uptake ratio was significantly decreased in RVPO and RVVO models, and was significantly increased in LVPO and LVVO models. Linear regression analysis showed an excellent correlation between LV/RV myocardial 201Tl uptake ratio and LV/RV mass ratio. Although the presence of significant correlation between LV/RV pressure ratio and LV/RV myocardial 201Tl uptake ratio was confirmed in PO models, rather poor correlation was observed in VO models. Our results suggest that LV/RV myocardial mass ratio as well as LV/RV pressure ratio can be evaluated by LV/RV myocardial 201Tl uptake ratio in chronic overload models. (S.Y.)

  12. A study of thallium scintigraphy for myocardial infarction performed within 72 hours of attack

    International Nuclear Information System (INIS)

    In 40 cases undergoing 201Tl myocardial scanning within 72 hours of attack of myocardial infarction, a significant correlation was found between the infarct size determined by myocardial scanning and the size of the infarction estimated on the basis of ECG findings and serum enzymes. The group with high pulmonary capillary wedge pressure was the group with low Tl scores. The group showing dyskinesis and aneurysm in left ventriculography showed low Tl scores and a significant correlation between the ejection fraction calculated from left ventriculograms and the Tl score. The above date indicate that 201Tl myocardial scanning in the acute phase after attack of infarction reflects the infarction size and cardiac function. (Chiba, N.)

  13. Comparison of myocardial thallium and ?-methyl iodophenyl pentadecanoic acid (BMIPP) distribution in cardiomyopathy hamster

    International Nuclear Information System (INIS)

    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 ?Ci) 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)

  14. Localization of exercise-induced myocardial ischemia with single view and biplanar radionuclide ventriculography: Validation in single vessel coronary disease

    Energy Technology Data Exchange (ETDEWEB)

    Currie, P.J.; Kelly, M.J.; Kalff, V.; Anderson, S.T.; Lim, Y.L.; Pitt, A.

    1985-08-01

    The ability of single view and biplanar radionuclide ventriculography (RVG) to determine the location of myocardial ischemia during maximal graded supine bicycle exercise was assessed in 50 patients with chest pain, no prior myocardial infarction, and a single coronary stenosis of >=50% luminal diameter narrowing at coronary angiography. A biplane collimator was used so that both right anterior oblique (RAO) gated first-pass and left anterior oblique (LAO) equilibrium RVG could be performed at rest and exercise. Results were compared with those obtained using 4-view /sup 201/Tl myocardial scintigraphy in the same patients. Regional wall motion abnormalities (WMA) and /sup 201/Tl perfusion defects were detected and assigned to individual coronary vessels by agreement of two of three independent observers, who read all studies blind along with those from control subjects with chest pain but no angiographically significant coronary artery disease. When scintigraphic abnormalities were detected, both biplanar RVG (36/39=92%) and /sup 201/Tl (25/25=100%) were more frequently correct in predicting the stenosed vessel than single view LAO RVG (24/32=75%) (P < 0.05). At RVG only inferior WMA, in the RAO view, predicted right coronary stenosis. Only posterolateral WMA, in the LAO view, predicted left circumflex stenosis. Thus biplanar, but not single view, LAO exercise RVG is a reasonable alternative to exercise /sup 201/Tl for localizing exercise-induced ischemic abnormalities to individual coronary stenosis.

  15. Localization of exercise-induced myocardial ischemia with single view and biplanar radionuclide ventriculography: Validation in single vessel coronary disease

    International Nuclear Information System (INIS)

    The ability of single view and biplanar radionuclide ventriculography (RVG) to determine the location of myocardial ischemia during maximal graded supine bicycle exercise was assessed in 50 patients with chest pain, no prior myocardial infarction, and a single coronary stenosis of >=50% luminal diameter narrowing at coronary angiography. A biplane collimator was used so that both right anterior oblique (RAO) gated first-pass and left anterior oblique (LAO) equilibrium RVG could be performed at rest and exercise. Results were compared with those obtained using 4-view 201Tl myocardial scintigraphy in the same patients. Regional wall motion abnormalities (WMA) and 201Tl perfusion defects were detected and assigned to individual coronary vessels by agreement of two of three independent observers, who read all studies blind along with those from control subjects with chest pain but no angiographically significant coronary artery disease. When scintigraphic abnormalities were detected, both biplanar RVG (36/39=92%) and 201Tl (25/25=100%) were more frequently correct in predicting the stenosed vessel than single view LAO RVG (24/32=75%) (P201Tl for localizing exercise-induced ischemic abnormalities to individual coronary stenosis. (orig.)

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

    International Nuclear Information System (INIS)

    Thallium-201 (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 minutes of infusion. Myocardial SPECT imaging was begun 5 minutes and 3 hours after the end of adenosine infusion. For evaluating the presence of perfusion defects, 2 short axis images at the basal and spical levels and a vertical long axis image at the mid left ventricle were used. The regions with decreased 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, p201Tl myocardial imaging during adenosine infusion was considered to be safe and useful for evaluating the patients with ischemic heart disease. (author)

  17. Evaluation of the clinical usefulness of a new myocardial imaging agent, 99mTc-tetrofosmin (PPN1011)

    International Nuclear Information System (INIS)

    The clinical usefulness of a new myocardial perfusion imaging agent, 99mTc-1,2-bis [bis (2-ethoxyethyl) phosphino] ethane (99mTc-Tetrofosmin, (PPN1011) was evaluated in 355 patients with various heart diseases. Both 1 and 2 day protocols resulted in images that were significantly clearer than those of 201Tl. The absence of significant drug related adverse reaction supported the safety of the agent for clinical use. Regional abnormalities detected by coronary arteriography agreed with 99mTc-Tetrofosmin SPECT findings in 74% and with 201Tl SPECT in 78% of this study. Eighty-four percent of an abnormalities were detected with 99mTc-Tetrofosmin SPECT, as compared with those detected with 201Tl SPECT (88.4%). The complete concordance ratio between 99mTc-Tetrofosmin and 201Tl images in segmental analysis was 87-89% at rest and stress. Since 99mTc-Tetrofosmin SPECT was judged clinically useful in 93.2% (331/255) of the patients studied, it is concluded that 99mTc-Tetrofosmin is a promising agent for myocardial perfusion imaging. The simple labeling procedure without heating and cooling is suitable for emergency administration. Reconditioning of myocardial perfusion could be evaluated with 99mTc-Tetrofosmin injection before and after interventional therapy. These are additional features of the agent for clinical use. (author)

  18. [Myocardial involvement in rhabdomyolysis caused by acute heroin intoxication].

    Science.gov (United States)

    Melandri, R; De Tommaso, I; Zele, I; Rizzoli, D; Rapezzi, C; Pezzilli, R; Re, G; Fontana, G

    1991-06-01

    It is well known that heroin overdose may cause rhabdomyolysis. Sometimes a myocardial involvement complicates its course. We report a case of heroin intoxication followed by rhabdomyolysis associated with myocardial injury, with symptoms, laboratory findings, ECG and echocardiography features of non-Q wave infarction. However, a 201 Tl myocardial scintigraphy, performed after patient discharging, did not show any abnormality. We think that heroin has a direct myotoxic effect on both myocardium and skeletal muscle. Yet we cannot exclude that hypoxia, acidosis, vasoconstrictive substances released by muscle necrosis, or hypersensitivity reactions associated with heroin or some of its adulterants are involved in myocardial injury. PMID:1924987

  19. Single-photon source characterization with infrared-sensitive superconducting single-photon detectors

    OpenAIRE

    Hadfield, Robert H.; Stevens, Martin J.; Mirin, Richard P.; Nam, Sae Woo

    2006-01-01

    Single-photon sources and detectors are key enabling technologies in quantum information processing. Nanowire-based superconducting single-photon detectors (SSPDs) offer single-photon detection from the visible well into the infrared with low dark counts, low jitter and short dead times. We report on the high fidelity characterization (via antibunching and spontaneous emission lifetime measurements) of a cavity-coupled single-photon source at 902 nm using a pair of SSPDs. The twin SSPD scheme...

  20. Study of single photon production at AMY

    International Nuclear Information System (INIS)

    Using 148 pb-1 data collected by the AMY detector, we have observed 4 single photon production events, while 4.0 events are expected from e+e- ? ???-bar. So far, we observed no significant excess of single photon production events over the Standard Model prediction. (J.P.N.)

  1. Myocardial uptake of meta-(/sup 123/I)-iodobenzylguanidine ((/sup 123/I)-MIBG) in patients with myocardial infarct

    Energy Technology Data Exchange (ETDEWEB)

    Fagret, D.; Comet, M.; Wolf, J.E.

    1989-09-01

    Meta-/sup 123/I-iodobenzylguanidine (/sup 123/I-MIBG), which is an analog of norepinephine, can be used to evaluate the integrity and function of sympathetic nerve endings in the heart. Myocardial uptake of /sup 123/I-MIBG was studied in 30 myocardial infarction patients and compared with the distribution of blood flow assessed with /sup 201/Tl. It was found that when a cold defect appeared on the /sup 201/Tl scintigram, its localization was identical to the cold defect on the /sup 123/I-MIBG scintigram. On the other hand, in three cases, a defect was found on the /sup 123/I-MIBG scintigram, corresponding to the electrocardiographic localization of the infarct, whereas the /sup 201/Tl scintigram was normal. Most strikingly, the present study shows that drugs (antagonists of the adrenergic receptors, calcium antagonists, amiodarone) decrease or even abolish (as in the case of labetalol) myocardial uptake of /sup 123/I-MIBG. Consequently, any interpretation of the /sup 123/I-MIBG scintigram must take into account the treatment administered. (orig.).

  2. Purification of single-photon entanglement.

    Science.gov (United States)

    Salart, D; Landry, O; Sangouard, N; Gisin, N; Herrmann, H; Sanguinetti, B; Simon, C; Sohler, W; Thew, R T; Thomas, A; Zbinden, H

    2010-05-01

    Single-photon entanglement is a simple form of entanglement that exists between two spatial modes sharing a single photon. Despite its elementary form, it provides a resource as useful as polarization-entangled photons and it can be used for quantum teleportation and entanglement swapping operations. Here, we report the first experiment where single-photon entanglement is purified with a simple linear-optics based protocol. In addition to its conceptual interest, this result might find applications in long distance quantum communication based on quantum repeaters. PMID:20482160

  3. Using adaptive neuro-fuzzy inference system technique for crosstalk correction in simultaneous 99mTc/201Tl SPECT imaging: A Monte Carlo simulation study

    International Nuclear Information System (INIS)

    This work presents a simulation based study by Monte Carlo which uses two adaptive neuro-fuzzy inference systems (ANFIS) for cross talk compensation of simultaneous 99mTc/201Tl dual-radioisotope SPECT imaging. We have compared two neuro-fuzzy systems based on fuzzy c-means (FCM) and subtractive (SUB) clustering. Our approach incorporates eight energy-windows image acquisition from 28 keV to 156 keV and two main photo peaks of 201Tl (77±10% keV) and 99mTc (140±10% keV). The Geant4 application in emission tomography (GATE) is used as a Monte Carlo simulator for three cylindrical and a NURBS Based Cardiac Torso (NCAT) phantom study. Three separate acquisitions including two single-isotopes and one dual isotope were performed in this study. Cross talk and scatter corrected projections are reconstructed by an iterative ordered subsets expectation maximization (OSEM) algorithm which models the non-uniform attenuation in the projection/back-projection. ANFIS-FCM/SUB structures are tuned to create three to sixteen fuzzy rules for modeling the photon cross-talk of the two radioisotopes. Applying seven to nine fuzzy rules leads to a total improvement of the contrast and the bias comparatively. It is found that there is an out performance for the ANFIS-FCM due to its acceleration and accurate results

  4. Using adaptive neuro-fuzzy inference system technique for crosstalk correction in simultaneous 99mTc/201Tl SPECT imaging: A Monte Carlo simulation study

    Science.gov (United States)

    Heidary, Saeed; Setayeshi, Saeed

    2015-01-01

    This work presents a simulation based study by Monte Carlo which uses two adaptive neuro-fuzzy inference systems (ANFIS) for cross talk compensation of simultaneous 99mTc/201Tl dual-radioisotope SPECT imaging. We have compared two neuro-fuzzy systems based on fuzzy c-means (FCM) and subtractive (SUB) clustering. Our approach incorporates eight energy-windows image acquisition from 28 keV to 156 keV and two main photo peaks of 201Tl (77±10% keV) and 99mTc (140±10% keV). The Geant4 application in emission tomography (GATE) is used as a Monte Carlo simulator for three cylindrical and a NURBS Based Cardiac Torso (NCAT) phantom study. Three separate acquisitions including two single-isotopes and one dual isotope were performed in this study. Cross talk and scatter corrected projections are reconstructed by an iterative ordered subsets expectation maximization (OSEM) algorithm which models the non-uniform attenuation in the projection/back-projection. ANFIS-FCM/SUB structures are tuned to create three to sixteen fuzzy rules for modeling the photon cross-talk of the two radioisotopes. Applying seven to nine fuzzy rules leads to a total improvement of the contrast and the bias comparatively. It is found that there is an out performance for the ANFIS-FCM due to its acceleration and accurate results.

  5. Using adaptive neuro-fuzzy inference system technique for crosstalk correction in simultaneous {sup 99m}Tc/{sup 201}Tl SPECT imaging: A Monte Carlo simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Heidary, Saeed, E-mail: saeedheidary@aut.ac.ir; Setayeshi, Saeed, E-mail: setayesh@aut.ac.ir

    2015-01-11

    This work presents a simulation based study by Monte Carlo which uses two adaptive neuro-fuzzy inference systems (ANFIS) for cross talk compensation of simultaneous {sup 99m}Tc/{sup 201}Tl dual-radioisotope SPECT imaging. We have compared two neuro-fuzzy systems based on fuzzy c-means (FCM) and subtractive (SUB) clustering. Our approach incorporates eight energy-windows image acquisition from 28 keV to 156 keV and two main photo peaks of {sup 201}Tl (77±10% keV) and {sup 99m}Tc (140±10% keV). The Geant4 application in emission tomography (GATE) is used as a Monte Carlo simulator for three cylindrical and a NURBS Based Cardiac Torso (NCAT) phantom study. Three separate acquisitions including two single-isotopes and one dual isotope were performed in this study. Cross talk and scatter corrected projections are reconstructed by an iterative ordered subsets expectation maximization (OSEM) algorithm which models the non-uniform attenuation in the projection/back-projection. ANFIS-FCM/SUB structures are tuned to create three to sixteen fuzzy rules for modeling the photon cross-talk of the two radioisotopes. Applying seven to nine fuzzy rules leads to a total improvement of the contrast and the bias comparatively. It is found that there is an out performance for the ANFIS-FCM due to its acceleration and accurate results.

  6. Biokinetics of 201Tl

    International Nuclear Information System (INIS)

    In retention of Tl in blood is similar to that of K. Animal experiments and studies in humans have shown a half-life of 5 min for Tl elimination from blood. In contrast, renal clearance is only 4% during the first 24 h. After i.v. application, Tl is quickly distributed throughout the organism with the highest concentrations in the kidneys. In humans, the biological half-live is 9.8 d, i.e. the effective half-life is 5 h. Tl biokinetics can be influenced by various factors and by certain drugs. (MG)

  7. Use of myocardial perfusion imaging and estimation of associated radiation doses in Germany from 2005 to 2012

    Energy Technology Data Exchange (ETDEWEB)

    Lindner, O.; Burchert, W. [University Hospital of the Ruhr University Bochum, Institute of Radiology, Nuclear Medicine and Molecular Imaging, Heart and Diabetes Center North Rhine-Westphalia, Bad Oeynhausen (Germany); Bengel, F.M. [Hanover Medical School, Department of Nuclear Medicine, Hanover (Germany); Hacker, M. [Medical University of Vienna, Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Vienna (Austria); Schaefer, W. [Kliniken Maria Hilf GmbH, Clinic of Nuclear Medicine, Moenchengladbach (Germany); Collaboration: Working Group Cardiovascular Nuclear Medicine of the German Society of Nuclear Medicine

    2014-05-15

    For several years the Working Group Cardiovascular Nuclear Medicine of the German Society of Nuclear Medicine has been performing a regular survey to obtain information on technique, utilization and development of myocardial perfusion scintigraphy (MPS). Currently, data of six surveys from 2005 to 2012 are available. The aim of this paper is to deliver a general and comprehensive overview of all surveys documenting the course of patient doses over time and the development of the method. A one-page questionnaire with number of MPS patients, number of stress and rest MPS, referral structure and several technical issues was sent to all centres performing MPS in Germany and evaluated. With the data on protocol utilization, effective MPS patient doses were estimated. MPS per million population (pmp) varied between 2,380 and 2,770. In 2012, MPS pmp showed a slight increase for the first time. From 2005 to 2009 the angiography to MPS ratio increased from 3.4 to 4.4, and the revascularization to MPS ratio decreased from 0.66 to 0.53. In 2012, both indices demonstrated an opposite trend for the first time (4.1 and 0.55). A total of 108 centres participated in all surveys. They showed an increase in MPS patients of 4.0 % over the reporting period. In 2012, more than 50 % of the centres experienced no change or an increase in MPS numbers. The leading single competitor was MRI, followed by angiography and stress echocardiography. {sup 201}Tl studies have decreased since 2005 from 20 to 5 %. {sup 99m}Tc MPS studies showed a mild increase in 2-day protocols. In 2012, the average effective dose per patient was estimated at 7.4 mSv. Due to the decreasing use of {sup 201}Tl, a mild decline over the observation period can be documented. Dynamic exercise stress was the most common stress test and adenosine the leading pharmacological stress agent, with a growing percentage. In 2012, the regadenoson percentage was 9 %. Gated single photon emission computed tomography (SPECT) noted an increasing acceptance with >70 % in 2012. The segmental scoring of perfusion studies had a low acceptance. Ambulatory care cardiologists represented the major referral group. Germany has a moderate to moderate-high MPS utilization rate. Nevertheless, coronary artery disease (CAD) diagnosis and disease management are dominated by angiography. The survey data reveal a positive trend in MPS and a decrease in average patient dose reflecting good practice with guideline adherence, the implementation of technical improvements and success in training. (orig.)

  8. Use of myocardial perfusion imaging and estimation of associated radiation doses in Germany from 2005 to 2012

    International Nuclear Information System (INIS)

    For several years the Working Group Cardiovascular Nuclear Medicine of the German Society of Nuclear Medicine has been performing a regular survey to obtain information on technique, utilization and development of myocardial perfusion scintigraphy (MPS). Currently, data of six surveys from 2005 to 2012 are available. The aim of this paper is to deliver a general and comprehensive overview of all surveys documenting the course of patient doses over time and the development of the method. A one-page questionnaire with number of MPS patients, number of stress and rest MPS, referral structure and several technical issues was sent to all centres performing MPS in Germany and evaluated. With the data on protocol utilization, effective MPS patient doses were estimated. MPS per million population (pmp) varied between 2,380 and 2,770. In 2012, MPS pmp showed a slight increase for the first time. From 2005 to 2009 the angiography to MPS ratio increased from 3.4 to 4.4, and the revascularization to MPS ratio decreased from 0.66 to 0.53. In 2012, both indices demonstrated an opposite trend for the first time (4.1 and 0.55). A total of 108 centres participated in all surveys. They showed an increase in MPS patients of 4.0 % over the reporting period. In 2012, more than 50 % of the centres experienced no change or an increase in MPS numbers. The leading single competitor was MRI, followed by angiography and stress echocardiography. 201Tl studies have decreased since 2005 from 20 to 5 %. 99mTc MPS studies showed a mild increase in 2-day protocols. In 2012, the average effective dose per patient was estimated at 7.4 mSv. Due to the decreasing use of 201Tl, a mild decline over the observation period can be documented. Dynamic exercise stress was the most common stress test and adenosine the leading pharmacological stress agent, with a growing percentage. In 2012, the regadenoson percentage was 9 %. Gated single photon emission computed tomography (SPECT) noted an increasing acceptance with >70 % in 2012. The segmental scoring of perfusion studies had a low acceptance. Ambulatory care cardiologists represented the major referral group. Germany has a moderate to moderate-high MPS utilization rate. Nevertheless, coronary artery disease (CAD) diagnosis and disease management are dominated by angiography. The survey data reveal a positive trend in MPS and a decrease in average patient dose reflecting good practice with guideline adherence, the implementation of technical improvements and success in training. (orig.)

  9. Effects of heart rate on myocardial thallium-201 uptake and clearance

    International Nuclear Information System (INIS)

    The effects of heart rate on the myocardial uptake and clearance of 201Tl were studied prospectively in seven healthy men, mean age 43 +/- 7 (s.d.) yr. Initial and delayed (3 hr) thallium images were obtained in three views after three bicycle exercise tests: to maximal, 80% and 60% of predicted maximal heart rate. The mean of three views initial myocardial 201Tl uptake was higher at maximal than at both 80% and 60% of predicted maximal heart rate, being 81% (p less than 0.01) and 60% (p less than 0.01) of maximal activity, respectively. The myocardial activity in the delayed images was identical. There was a linear relationship between heart rate and the initial myocardial activity, r = 0.86 (p less than 0.001). The mean (range) 201Tl clearance was 58% (51-65), 47% (34-56), and 34% (22-49) (all differences p less than 0.01), respectively. Concordance among the three individual views in estimating clearance was best for the highest exercise level. There was a linear relationship between heart rate and clearance, r = 0.80 (p less than 0.001). Clearance was altered by only 1.67 x 10%/heart bpm (0.024 hr/heart beat). Clearance in the liver, spleen and lungs increased at submaximal exercise levels. Thus, a linear relationship between heart rate and clearance is the result of changes in the initial exercise myocardial 201Tl activity. Submaximal exercise may reduce reproducibility of clearance estimation, and the change of myocardial clearance with heart rate seems less than previously suggested

  10. Exercise study of thallium-201 myocardial imaging and coronary arteriography

    International Nuclear Information System (INIS)

    Myocardial imaging with intravenous thallium-201 (Tl) was performed following bycycle ergometer exercise (Ex) and redistribution study (Rd) was performed after 4 hours of injection in 16 patients suspected coronary artery disease (CAD). Of 5 patients with no or insignificant CAD (= 75% diameter stenosis, 6 with angina pectoris, 5 with old myocardial infarction), 6(55%) had Ex Tl defect (Sensitivity 55%), 5 of 6 patients (83%) had significant collateral circulation, and 7(64%) had Ex ST-segment depression. We conclude that positive Ex Tl-myocardial imaging is highly suggestive of CAD (Predictive value 100%). (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1991-08-01

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

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

    International Nuclear Information System (INIS)

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

  13. Cavity-based single-photon sources

    OpenAIRE

    Kuhn, A; Ljunggren, D

    2010-01-01

    We introduce the basic concepts and characteristic properties of single-photon emitters based on resonator effects in optical cavities, and provide a review of the most prominent implementations. First we discuss the elementary principles of cavity quantum electrodynamics, which determine how single quantum systems couple to the quantised field modes of optical resonators, and then show how to exploit these principles in order to generate single photons on demand. Furthermore, we elucidate ho...

  14. Correlation between thallium-201 myocardial perfusion defects and the functional severity of coronary artery stenosis as assessed by pressure-derived myocardial fractional flow reserve

    International Nuclear Information System (INIS)

    Although a relationship between the coronary pressure-derived fractional flow reserve (FFR) and the presence of myocardial ischemia as demonstrated by radionuclide imaging has been reported in a select group of patients, it remains to be established whether this relation also holds true in actual clinical settings with a heterogeneous group of patients. Accordingly, 194 coronary vessels and their supply territories were evaluated in 165 consecutive patients with suspected or known coronary artery disease. An FFR 201Tl (p201Tl reversibility score (r=-0.62; p<0.0001). These results suggest that the FFR has a significant relationship with scintigraphic evidence of myocardial ischemia and can be regarded as a marker of its presence or absence in patients in actual clinical settings. (author)

  15. Imaging of cocaine-induced global and regional myocardial ischemia

    International Nuclear Information System (INIS)

    Severe and often fatal cardiac complications have been reported in cocaine users with narrowed coronary arteries caused by atherosclerosis as well as in young adults with normal coronaries. The authors have found that in normal dogs cocaine induces severe temporary hypoperfusion of the left ventricle as indicated by a significantly lower 201Tl concentration compared to the baseline state. The most significant decrease in uptake occurred 5 min after injection and was more pronounced in the septal and apical segments. Following intravenous administration of cocaine, instead of gradual disappearance of 201Tl from the left ventricle, there was continuous increase in 201Tl concentration in the left ventricle. These imaging experiments indicate that the deleterious effects of cocaine on the heart are probably due to spasm of the coronaries and decreased myocardial perfusion. Since spasm of the large subpericardial vessels does not seem to explain the magnitude of the increased coronary resistance and decreased coronary flow after cocaine as described in the literature, it is suggested that microvascular spasm of smaller vessels plays a major role in the temporary decrease in perfusion. The data may also suggest that severe temporary myocardial ischemia is probably the initiating factor for the cardiac complications induced by cocaine

  16. Myocardial perfusion imaging for the detection of coronary heart disease

    International Nuclear Information System (INIS)

    A method of myocardial perfusion imaging using 201Tl is described. Thallium is able to substitute for potassium in biological systems including transport by the sodium--potassium ATP-ase system. The high extraction efficiency of the heart for 201Tl offers a method whereby a tracer may be administered intravenously and is concentrated to a significant degree by the heart. However, only about 3 to 4 percent of the dose administered lodges in the myocardium. Experiments with dogs indicated that the regional distribution of Tl in the heart reflects the regional distribution of blood flow. The goal is to develop a procedure that can detect those patients with significant disease prior to the onset of a catastrophic event and studies are being undertaken to improve the sensitivity of the method for the detection of smaller lesions in the myocardium

  17. Effect of beta blockade on single photon emission computed tomographic (SPECT) thallium-201 images in patients with coronary disease

    International Nuclear Information System (INIS)

    We evaluated the effect of beta blockers on thallium-201 (Tl-201) single photon emission computed tomographic (SPECT) imaging in 12 patients with coronary disease using an automated computer algorithm. Maximal exercise heart rate and blood pressure were reduced and exercise time was increased with beta blockers. Estimated stress defect size decreased from 47 +/- 36.3 gm during placebo treatment to 32 +/- 27.1 gm during beta blocker therapy (-32%; p less than 0.01). The placebo treatment redistribution defect was estimated to be 28 +/- 29.8 gm. It fell to 15 +/- 23.3 gm with beta blockade (-46%; p less than 0.005). All patients had a stress Tl-201 defect during placebo treatment and eight had redistribution defects consistent with residual scar. During beta blocker therapy, 2 of 12 patients had normal stress-redistribution studies and only five patients had redistribution defects. Beta blockade can reduce exercise and redistribution Tl-201 SPECT defect size significantly while simultaneously increasing exercise time and reducing angina. Beta blockers may unmask or may eliminate evidence of redistribution. Tl-201 SPECT imaging may be useful in defining the reduction in ischemia produced by cardiac drugs

  18. Physiological studies of environmental pollutants. Progress report, September 1, 1975--May 31, 1976. [/sup 210/Po, /sup 203/Pb, /sup 201/Tl, /sup 207/Bi, /sup 65/Zn

    Energy Technology Data Exchange (ETDEWEB)

    Lengemann, F W; Wentworth, R A

    1976-01-01

    In the past year we have looked at the transfer of some members of the actinide decay series into milk of goats. These were /sup 210/Po, /sup 203/Pb, /sup 201/Tl and /sup 207/Bi. All of these appeared in milk after oral ingestion but at levels less than 1 percent per liter. In addition we have looked at the transfer of /sup 65/Zn into milk of goats after oral and I.V. doses; the experiments are incomplete at this time. In controlled temperature studies it was found that 6.6 times as much radioiodine was secreted into milk when goats were at 33/sup 0/ as opposed to 5/sup 0/C. When radioiodine is put into the mammary gland the transfer from milk to body is rapid; more rapid than is the case for /sup 65/Zn. The analysis of these data indicate the need for a model capable of handling expansion of a compartment.

  19. Simple microcavity for single-photon generation.

    Science.gov (United States)

    Plakhotnik, Taras

    2005-04-18

    A new design of an optical resonator for generation of single-photon pulses is proposed. The resonator is made of a cylindrical or spherical piece of a polymer squeezed between two flat dielectric mirrors. The mode characteristics of this resonator are calculated numerically. The numerical analysis is backed by a physical explanation. The decay time and the mode volume of the fundamental mode are sufficient for achieving more than 96% probability of generating a single-photon in a single-mode. The corresponding requirement for the reflectivity of the mirrors (~99.9%) and the losses in the polymer (100 dB/m) are quite modest. The resonator is suitable for single-photon generation based on optical pumping of a single quantum system such as an organic molecule, a diamond nanocrystal, or a semiconductor quantum dot if they are imbedded in the polymer. PMID:19495201

  20. Measurement of the healing ability of ischemic ulcers in the lower limbs in chronic arterial obstructive disease using 201Tl-Cl

    International Nuclear Information System (INIS)

    Evaluation of the healing ability of ischemic ulcers by a method involving measurement of the ulcer index (U. I.) and mean ulcer index of toes (mU. I.) using 201Tl-Cl before and after the treatment of chronic arterial obstructive disease accompanied by ischemic ulcer was studied. The lesions consisted of 56 ulcers in 41 limbs. Reactive hyperemia following avascularization stress was used for measurement, and U. I. was determined according to the method of Siegel et al. For cases with toe ulcers, the mU. I. was measured from plantar scintigrams, twice under stress and upon redistribution after 3 hours' rest. The following results were obtained. 1) The healing ability of the cases with a U. I. value of more than 1.4 was good, but even among cases with a pretreatment U. I. of 0.9 - 1.4, ulcer healing was also good in cases in which the U. I. was maintained above 1.4 as a result of various treatments. 2) Significant increases in U. I. were observed in the arterial reconstruction group after treatment, compared to the conservative treatment group and the lumbar sympathectomy group. 3) The healing ability was good in cases with an mU. I. of more than 1.2 at stress except for 2 ASO cases complicated by diabetes. 4) Although it was difficult to prognosticate the healing ability of cases with an mU. I. of less than 1.2 before treatment, healing ability could be evaluated after treatment on the basis of the appearance of significant increase in blood flow on stress in the ulcerated toes. 5) A stress index seemed to reflect the ischemic conditions in ulcerated toes in relation to stress. 6) U. I. and mU. I. measured using 201Tl-Cl were significantly correlated with the degree of inflammatory and reactive hyperemia in the floor of ulcers and in the ulcerated toes. (J.P.N.)

  1. Clinical evaluation of multidrug-resistance in lung cancers with dual-isotope 99Tcm-MIBI and 201Tl SPECT imaging

    International Nuclear Information System (INIS)

    Objective: Multidrug-resistance (MDR) may be a powerful impact on chemotherapy of lung cancers. In vivo detecting MDR of lung cancer using dual-isotope 99Tcm-methoxyisobutylisonitrile (MIBI) and 201Tl SPECT imaging was evaluated. Methods: Eighty patients with lung cancer underwent dual-isotope SPECT study before chemotherapy. Regions of interest (ROI) were placed over the tumors (T), contralateral normal lung tissue (N) and heart (H) on transverse view, and T/N uptake ratio, T/H uptake ratio, clearance rate and retention index of both isotopes were calculated. These results were compared with the efficacy of the chemotherapy according to the following classification. Tumor regression greater than 50%, tumor regression greater than 30% and less than 50%, tumor regression less than 30% and tumor enlargement was recorded as partial and complete response (PR and CR), median response (MR), no response (NR) and progression (PQ), respectively. Results: 1) All parameters of 201Tl were of no significant relationship with the efficacy of chemotherapy. 2) The parameters of 99Tcm -MIBI uptake ratio, 99Tcm-MIBI clearance rate and 99Tcm-MIBI retention index with heart as background were superior to that with contralateral normal lung tissue as background. The values of 99Tcm-MIBI retention index were 0.24 +- 0.08, 0.20 +- 0.11, 0.16 +- 0.08, 0.14 +- 0.05 in CR, MR, NR, PQ, respectively. 3) When 99Tcm -MIBI clearance rate >20% was used as positive threshold, the positive and negative predictive values for NR and PQ were 71.2% and 64.3%, respectively. And when 99Tcm-MIBI retention index 99Tcm-MIBI SPECT imaging is a useful method for in vivo detection of MDR of lung cancers

  2. Factors affecting the myocardial activity acquired during exercise SPECT with a high-sensitivity cardiac CZT camera as compared with conventional Anger camera

    International Nuclear Information System (INIS)

    Injected doses are difficult to optimize for exercise SPECT since they depend on the myocardial fraction of injected activity (MFI) that is detected by the camera. The aim of this study was to analyse the factors affecting MFI determined using a cardiac CZT camera as compared with those determined using conventional Anger cameras. Factors affecting MFI were determined and compared in patients who had consecutive exercise SPECT acquisitions with 201Tl (84 patients) or 99mTc-sestamibi (87 patients) with an Anger or a CZT camera. A predictive model was validated in a group of patients routinely referred for 201Tl (78 patients) or 99mTc-sestamibi (80 patients) exercise CZT SPECT. The predictive model involved: (1) camera type, adjusted mean MFI being ninefold higher for CZT than for Anger SPECT, (2) tracer type, adjusted mean MFI being twofold higher for 201Tl than for 99mTc-sestamibi, and (3) logarithm of body weight. The CZT SPECT model led to a +1 ± 26 % error in the prediction of the actual MFI from the validation group. The mean MFI values estimated for CZT SPECT were more than twofold higher in patients with a body weight of 60 kg than in patients with a body weight of 120 kg (15.9 and 6.8 ppm for 99mTc-sestamibi and 30.5 and 13.1ppm for 201Tl, respectively), and for a 14-min acquisition of up to one million myocardial counts, the corresponding injected activities were only 80 and 186 MBq for 99mTc-sestamibi and 39 and 91 MBq for 201Tl, respectively. Myocardial activities acquired during exercise CZT SPECT are strongly influenced by body weight and tracer type, and are dramatically higher than those obtained using an Anger camera, allowing very low-dose protocols to be planned, especially for 99mTc-sestamibi and in non-obese subjects. (orig.)

  3. Myocardial SPECT in children with sickle cell disease

    International Nuclear Information System (INIS)

    Aim: While cerebral and bones strokes are well documented in children with sickle cell disease (SCD), impairment of myocardial perfusion is an unknown complication. Conventional techniques such as exercise testing and echocardiography have a low sensitivity and specificity to detect myocardial ischemia in patients with SCD. The aim of this prospective study was to assess myocardial perfusion with 201Tl SPECT in children with SCD. Materials and Methods: Twenty-two patients, aged 12 ± 4 years, were included. Myocardial perfusion was assessed by 201Tl SPECT after stress and 3 hours later after reinjection on a single head gammacamera equipped with a LEAP collimator (64x64 matrix size format, 30 projections over 1800, 30 seconds per step). Left ventricular ejection fraction (LVEF) was assessed by equilibrium radionuclide angiography at rest on the same day. Results: Myocardial perfusion was impaired in 13/22 patients: 8 had reversible defects and 5 had fixed defects. The left ventricular cavity was dilated in 13/22 patients. The mean LVEF was 63 ± 9%. There was no relationship between myocardial perfusion and left ventricular dilation or function. Conclusion: Myocardial perfusion is frequently impaired in children with SCD. Treatment with hydroxyurea should be considered in SCD patients with perfusion defects

  4. Room temperature stable single-photon source

    CERN Document Server

    Beveratos, A; Brouri, R; Gacoin, T; Poizat, J P; Grangier, P; Beveratos, Alexios; Kuehn, Sergei; Brouri, Rosa; Gacoin, Thierry; Poizat, Jean-Philippe; Grangier, Philippe

    2001-01-01

    We report on the realization of a stable solid state room temperature source for single photons. It is based on the fluorescence of a single nitrogen-vacancy (NV) color center in a diamond nanocrystal. Antibunching has been observed in the fluorescence light under both continuous and pulsed excitation. Our source delivers 2*10^4 single-photon pulses per second at an excitation repetition rate of 10 MHz. The number of two-photon pulses is reduced by a factor of five compared to strongly attenuated coherent sources.

  5. Fiber-assisted Single Photon Spectrograph

    CERN Document Server

    Avenhaus, Malte; Mosley, Peter J; Silberhorn, Christine

    2009-01-01

    We demonstrate the implementation of a fiber-integrated spectrograph utilizing chromatic group velocity dispersion (GVD) in a single mode fiber. By means of GVD we stretch an ultrafast pulse in time in order to spectrally resolve single photons in the time domain, detected by single photon counting modules with very accurate temporal resolution. As a result, the spectrum of a very weak pulse is recovered from a precise time measurement with high signal to noise ratio. We demonstrate the potential of our technique by applying our scheme to analyzing the joint spectral intensity distribution of a parametric downconversion source at telecommunication wavelength.

  6. Assessment of myocardial fatty acid metabolism in patients with vasospastic angina using 123I-BMIPP myocardial SPECT

    International Nuclear Information System (INIS)

    Myocardial perfusion and fatty acid metabolism may be unpaired in the patients of vasospastic angina (VSA), because abnormal regional wall motion of left ventricle has been shown in some cases of VSA without apparent history of myocardial infarction. To study the clinical utility of 123I-BMIPP scintigraphy in diagnosis of myocardial ischemia in VSA, both 123I-BMIPP (rest) and 201Tl (exercise) SPECT were performed in the 20 patients of VSA diagnosed by coronary angiography. Defect scores were calculated visually from the 17 segments of myocardial images and were compared with patient's anginal history, period from last attack, numbers of attack, left ventricular (LV) ejection fraction and severity of regional LV wall motion abnormality. 123I-BMIPP SPECT images showed decreased tracer uptake in 14 cases of 20 (70%) VSA patients. Exercise 201Tl SPECT images showed decreased tracer uptake in 3 cases of 20 (15%) of patients. Severity of regional LV wall motion abnormality was correlated with defect score of BMIPP. Though total defect score of BMIPP did not correlate with patient's anginal history, number of symptoms and LV ejection fraction, correlated inversely with period from last attack. It was suggested that 123I-BMIPP myocardial SPECT images in VSA patients showed 'memories' of myocardial ischemic damages induced by vasospasm. In summary, 123I-BMIPP myocardial SPECT images could be a useful test for diagnosis and evaluation of VSA. (author)

  7. Analysis of papillary muscle images on planar thallium-201 myocardial scintigrams in various heart diseases

    International Nuclear Information System (INIS)

    201Tl myocardial imaging can, noninvasively, visualize the various cardiac structures such as the left ventricle, right ventricle and, occasionally, the atrium. We have noted that certain patients exhibit a prominent appearance of the papillary muscle on a scintigram. Thus, we analyzed 201Tl myocardial scintigrams for evidence of activity which corresponded to the anterolateral (A-PM) and posteromedial (P-PM) papillary muscles. Twenty normal subjects, 81 patients with ischemic heart disease (IHD), 11 with hypertrophic cardiomyopathy (HCM) and 13 with dilated cardiomyopathy (DCM) were examined. Patients with DCM had rest imaging only, while the remaining ones performed exercise studies. The prevalence of a positive A-PM image was not high (9%-23%) and there was no significant difference among groups. The P-PM was seen in only 15% of the normal group and in 18% of the HCM group, while the prevalence was high in the IHD (34.6%) and DCM (53.8%) groups. In the IHD, the positive images of the P-PM were largely from the sub-group with single vessel left anterior descending (LAD) coronary artery disease (78.9%). However, even in the presence of a defect in the left ventricular wall supplied by the LAD coronary artery, the patients with multi-vessel coronary artery disease did not tend to disclose the P-PM on the scintigram (30.8%). Thus, we conclude that positive P-PM imaging on a planar 201Tl myocardial scintigram is frequently observed under some cardiac states and seems to be related to reduced wall motion, sound blood supply to the P-PM and the existence of a defect in the anterior left ventricular wall overlapping the P-PM. When we analyze the planar 201Tl myocardial scintigram, not only the left and right ventricles, but also the PM should be assessed. (orig.)

  8. Influence of age on serial change in TL/BMIPP dual isotope SPECT images after direct PTCA in patients with acute myocardial infarction

    International Nuclear Information System (INIS)

    The purpose of this study was to investigate the influence of age on serial change in 201TlCl (TL) and 123I-BMIPP (BMIPP) dual isotope single photon emission computed tomography (SPECT) images after direct PTCA in patients (pts) with acute myocardial infarction (MI). Dual SPECT with TL and BMIPP at rest, radionuclide ventriculography for left ventricular ejection fraction (LVEF), and two-dimensional echocardiography for wall motion analysis were performed in 26 pts at the subacute and chronic phases after direct PTCA for acute MI. A defect score (DS) for SPECT images was interpreted as normal: 0, mildly decreased: 1, moderately or severely decreased: 2, complete defect: 3. The difference in DS between TL and BMIPP was defined as the mismatch score (MS). DS in BMIPP was greater than that in TL at the subacute phase in all pts. Significant improvement in the wall motion score was recognized in pts who showed TL/BMIPP discrepancy at the subacute phase. Pts were classified by age into two groups; group I: younger than 65 years old (n=18); group II: 65 years and older (n=8). Improvement of MS from the subacute to chronic phase was significant in group I (5.2±1.9 to 3.2±1.9, p=0.0001), whereas not significant in group II (6.2±2.9 to 6.1±2.9, NS). There was a significant negative correlation between relative MS (ratio of subacute MS to chronic MS) and age (r=-0.78, p<0.0001). No significant correlation was observed between age and improvement in LVEF. There results indicate that disordered myocardial fatty acid metabolism, reflected by TL/BMIPP discrepancy, persist longer in elderly pts than younger pts after acute MI. (author)

  9. Effect of nicardipine on painless myocardial ischemia

    International Nuclear Information System (INIS)

    201Tl myocrdial scintigraphy was performed in 29 patients with coronary heart diseaes and painless myocardial ischemic episodes revealed during a long-term monitoring of ST segment. The paintless ST segment depression episodes and long high-amplitude painless ST segment elevations were found to be indicative of a significant severity of pathological processes in the myocardium. A 12-day nicardipine monotherapy produced antianginal and hypotensive effects and contributed to decrease in the frequency, duration, and amplitude of painless ST-segment depressions and in the duration of paintless ST-segment elevations

  10. Interactive Screen Experiments with Single Photons

    Science.gov (United States)

    Bronner, Patrick; Strunz, Andreas; Silberhorn, Christine; Meyn, Jan-Peter

    2009-01-01

    Single photons are used for fundamental quantum physics experiments as well as for applications. Originally being a topic of advance courses, such experiments are increasingly a subject of undergraduate courses. We provide interactive screen experiments (ISE) for supporting the work in a real laboratory, and for students who do not have access to…

  11. Single Photon Experiments and Quantum Complementarity

    Directory of Open Access Journals (Sweden)

    Georgiev D. D.

    2007-04-01

    Full Text Available Single photon experiments have been used as one of the most striking illustrations of the apparently nonclassical nature of the quantum world. In this review we examine the mathematical basis of the principle of complementarity and explain why the Englert-Greenberger duality relation is not violated in the configurations of Unruh and of Afshar.

  12. Single photon tomoscintigraphy: evolution and future prospects

    International Nuclear Information System (INIS)

    The purpose of this report is to review single photon emission computed tomography systems using conventional rotating gamma cameras, their evolution and future prospects and systems using multi-crystal gamma cameras (TOMOMATIC, HEADTOME, MULTI-X 810, SPRINT) and annular single crystal cameras (MUMPI, ASPECT)

  13. Effect of verapamil on myocardial ischemia in patients with hypertrophic cardiomyopathy

    International Nuclear Information System (INIS)

    The effect of verapamil myocardial ischemia in patients with hypertrophic cardiomyopathy (HCM) was evaluated exercise myocardial 201TlSPECT (EX-Tl). EX-Tl was performed before and after 8.1±6.1 weeks of oral administration of verapamil (240 mg/day) on 20 patients with HCM who showed transient 201Tl perfusion defects under control conditions. SPECT images were divided into nine segments. The 201Tl perfusion defect was visually scored and evaluated for four grades in each segment and the sum total grade was calculated as the defect score. Transient dilation index was calculated as a reflection of subendocardial ischemia. Improvements in defect score were demonstrated in 18 of 20 patients after administration of verapamil. The mean defect score decreased significantly from 5.1±2.3 to 2.5±2.4 (p<0.001). Although 18 of 20 patients showed abnormal transient dilation index under control conditions, 16 showed improvement and 12 were normalized after verapamil therapy. Mean transient dilation index decreased from 1.24±0.19 to 1.08±0.10 (p<0.01). Verapamil improves myocardial ischemia on patients with HCM. (author)

  14. Effect of verapamil on myocardial ischemia in patients with hypertrophic cardiomyopathy

    International Nuclear Information System (INIS)

    Effect of verapamil on myocardial ischemia in patients with hypertrophic cardiomyopathy (HCM) was evaluated by exercise stress myocardial 201Tl SPECT (EX-Tl). EX-Tl was performed before and after 8.8 weeks of oral verapamil (240 mg/day) in 12 patients with HCM who showed transient 201Tl perfusion defects under control conditions. 201Tl perfusion defect was visually scored and judged for 4 grades as normal (0), mild defect (1), moderate defect (2), and severe defect (3). Transient dilation index (TDI) was calculated as an index of subendocardial ischemia. Improvements of defect score were demonstrated in 10 patients after administration of verapamil. Two patients showed no change of defect score. Mean defect score decreased significantly from 5.50 to 3.03 (p<0.001). Although 11 of 12 patients showed abnormal TDI under control conditions, 10 of these revealed improvements of TDI and 7 of the 10 disclosed normal TDI after verapamil. Mean TDI decreased from 1.263 to 1.090 significantly (p<0.01). In conclusion, verapamil may improve myocardial ischemia in patients with HCM. (author)

  15. 99mTc-MIBI (RP-30) to define the extent of myocardial ischemia and evaluate ventricular function

    International Nuclear Information System (INIS)

    99mTc-MIBI, a new myocardial perfusion agent, is a technetium labeled isonitrile derivative. We have taken advantage of the physical characteristics of 99mTc to combine at rest, post infarction, ventricular function studies with analysis of perfusion. We have studied at rest and at stress, 22 patients with coronary artery disease selected on the basis of an abnormal coronary angiogram or on the basis of a positive exercise ECG stress test for symptomatic angina. We have also studied at rest only, 20 patients with a previous myocardial infarction. A comparative thallium planar scintigraphy was obtained for all patients. The sensitivity of 99mTc-MIBI scintigraphy for detecting individual vessel lesions at stress was 88% as compared with 83% for 201Tl. Sensitivity was higher in patients with previous myocardial infarction (93% for the 2 isotopes) than in patients without (85% for 99mTc-MIBI versus 81% for 201Tl). Segmental myocardial correspondence between 99mTc-MIBI and 201Tl was very close (92%). The overall sensitivity for the detection of acute myocardial infarction reached respectively 91% for 99mTc MBIB and 87% for 201Tl. The specificity in the regions corresponding to arteries not involved was excellent for both tracers as we did not observe any false positive result. The correlation between first pass left ventricular ejection fraction obtained with 99mTc-MIBI and equilibrium left ventricular ejection fraction obtained with 99mTc red cells was excellent (r=0.96). It was not as good but was still satisfactory for the right ventricle (r=0.75). By comparison of diastolic and systolic frames, gated tomography provides analysis of regional wall motion and wall thickening. (orig.)

  16. Myocardial accumulation of iodinated beta-methyl-branched fatty acid analogue, iodine-125-15-(p-iodophenyl)-3-(R,S)methylpentadecanoic acid (BMIPP), in relation to ATP concentration

    International Nuclear Information System (INIS)

    To clarify the relationship between the myocardial accumulation of 125I-15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) and intracellular adenosine-5'-triphosphate (ATP) content, the effect of 2,4-dinitrophenol (DNP, an electron transport uncoupler) on myocardial BMIPP accumulation was studied, in comparison with that of thallium-201-chloride (201Tl-Cl). In the mouse myocardium, DNP decreased the intracellular ATP and ADP levels, without affecting either acyl-CoA synthetase activity or the level of CoA-SH. Following treatment with DNP, decreases in myocardial BMIPP accumulation correlated well with those of ATP, while 201Tl-Cl showed slightly increased accumulation in the myocardium. Thus, in some diseases, BMIPP may be useful in evaluating myocardial ATP levels

  17. Detection of myocardial viability by means of Single Proton Emission Computed Tomography (Perfused SPECT) dual {sup 201} Tl (rest of 15 minutes, 24 late hours and 24 hours reinjection) and gated-SPECT {sup 99m} Tc-SESTAMIBI in effort or stimulation of the coronary reserves; Deteccion de viabilidad miocardica mediante tomografia por emision de foton unico (SPECT perfusorio) dual {sup 201} Talio (Reposo de 15 minutos, 24 horas tardio y 24 horas reinyeccion) y gated-SPECT {sup 99m} Tc-SESTAMIBI en esfuerzo o estimulo de reserva coronaria

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza V, R

    2004-07-01

    The objective of this work was to determine if the images of SPECT {sup 201} TI in rest of 15 minutes, 24 late hours and Gated-SPECT {sup 99m} Tc-SESTAMIBI in effort or stimulation of coronary reservation correlate with the study of 24 hours post reinjection of {sup 201}TI 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 {sup 201} TI in rest with images of 15 minutes, 24 late hours and 24 hours reinjection, by means of the administration of {sup 201}TI to dose of 130 MBq and reinjection with 37 MBq. and Gated-SPECT {sup 99m}Tc-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)

  18. The value of dipyridamole 201TI SPECT myocardial perfusion imaging in ischemicc adult viral myocarditis

    International Nuclear Information System (INIS)

    Objective: The aim of this study was to explore the characteristics of dipyridamole 201Tl SPECT myocardial perfusion imaging in patients clinically suspected of ischemic adult viral myocarditis (IAVM) based on electrocardiogram (ECG) changes. Methods: Seventy-nine patients.age range 19-55, were studied in their post. IAVM sequelae period. All patients underwent pharmacologically stressed 201Tl SPECT myocardial perfusion imaging after infusing 0.56 mg dipyridamole/kg intravenous iu 4 min. The early and delayed SPECT images were acquired respectively at 10 min and 240 min after 201Tl injection. Three-dimen-sional reconstructions of the original images were analyzed and reported by two or more experienced nuclear medicine physicians. The results of imaging between male and female genders were compared using ?2-test with SAS 8.1 software. Results: There were no abnormal myocardial perfusion findings in the early stress images in all patients. In the delayed study, however, 43.04% (34/79) of patients had abnormal results with reversed perfusion defects in 36 segments, including 9 segments (25.00%) in the anterior wall.11 segments (30.56%) in the inferior wall, 8 segments (22.22%) in the antero-septal wall, 4 segments (11.11%) in the antero-lateral wall, and 4 segments (11.11%) in the apex. The perfusion defect of single segment was found in 32 patients. Reversed defects were identified in 70.83% (17/24) of male and 30.91% (17/55) of female. There was a significant difference in proportion of abnormal findings between male and female genders (?2=10.86. P201Tl SPECT mvocardial perfusion imaging may have a value for diagnosis and treatment of the ischemic adult viral myocarditis. The ECG ST-T changes found in female may have higher false positive results and cautions should be taken. (authors)

  19. Phase 3 study of ?-methyl-p-(123I)-iodophenyl-pentadecanoic acid, a myocardial imaging agent for evaluating fatty acid metabolism

    International Nuclear Information System (INIS)

    A multi-center trial of ?-methyl-p-(123I)-iodophenyl-pentadecanoic acid (123I-BMIPP) was performed to assess its clinical usefulness in the evaluation of myocardial fatty acid metabolism in 587 patients with various heart diseases. 123I-BMIPP showed relatively decreased uptake compared with 201Tl in the myocardial lesions of 62% of patients with ischemic heart disease (IHD), 39% of those with cardiomyopathy and 32% of those with other heart diseases. In case of myocardial infarction, less uptake of 123I-BMIPP (Type B) than 201Tl was more frequently seen in patients with successful recanalization than in those without recanalization. The patients with matched distribution of the two tracers (Type E) increased in the direct proportion to the interval between the onset of myocardial infarction and the radionuclide studies. The uptake of 123I-BMIPP correlated well with myocardial viability evaluated by 201Tl exercise-redistribution studies. Type B was frequently seen in the areas with 201Tl redistribution, while Type E was seen in the fixed defect areas. In the other heart diseases studied, Type E was observed in approximately 60% of patients with dilated or secondary cardiomyopathies. Type B was seen in about 45% of patients with valvular heart diseases and myocarditis. Various types of mismatch between the two tracers were demonstrated in hypertrophic cardiomyopathy and hypertensive heart disease. It is concluded that 123I-BMIPP is a safe and useful agent for the diagnosis of various heart diseases, since it reflects myocardial fatty acid metabolism. (author)

  20. Feasibility of single photon tomography with RB-82

    International Nuclear Information System (INIS)

    Rb-82 (t 1/2 = 75 sec) is a positron emitting myocardial perfusion tracer available from a long lived (t 1/2 = 25d) Sr-82 generator. The authors have imaged Rb-82 in the single photon mode using a Pho-TV gamma camera with a parallel hole rotating tungsten collimator but only one view of the heart is obtained with each Rb-82 injection. For exercise studies with Rb-82, tomographic myocardial imaging is desirable. Because of the limited availability of ECT instrumentation, the clinical utilization of this tracer will be enhanced by the development of suitable instrumentation for imaging high energy photons in standard nuclear medicine units. A 7 pinhole collimator capable of imaging high energy photons was designed for an LFOV camera. It was built with thick shielding (2 1/2'' of lead) which largely preserved the geometry of the original system designed for low energy tracers and myocardial images obtained with N-13 ammonia were previously reported. Using 4mm pinhole inserts of tungsten, Rb-82 imaging was performed at rest in 4 male subjects after injection of tracer intravenously in doses up to 60 mCi. A commercially available software program for a DEC Gamma-11 which was designed to avoid exaggeration of lesions was used to reconstruct activity imaged from 2 - 7 minutes after injection. Tomographic sections of good quality were obtained. Sequential rest and exercise studies should be feasible with this technique of tomographic myocardial imaging. The short half life of the tracer also allows detection of changing patterns during the redistribution phase with serial injections after exercise

  1. Detection of hibernating myocardium in patients with myocardial infarction by low-dose dobutamine echocardiography. Comparison with thallium-201 scintigraphy with reinjection

    International Nuclear Information System (INIS)

    The identification of hibernating myocardium is important for selecting patients who will benefit from coronary revascularization. The relationship between echocardiographic and radioisotopic markers of hibernating myocardium and postrevascularization recovery of myocardial function was investigated in 21 patients who underwent successful revascula