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Perfusion Scintigraphy (perfusion + scintigraphy)

Distribution by Scientific Domains

Medical Sciences	100%

Kinds of Perfusion Scintigraphy

myocardial perfusion scintigraphy

Selected Abstracts

Lipid Risk Factor Correlates of Ischemic Heart Disease as Diagnosed by Myocardial Perfusion Scintigraphy

PREVENTIVE CARDIOLOGY, Issue 4 2000
Kevin A. Bybee MD
Patients with known coronary artery disease frequently change their lifestyles (e.g., diet, exercise, and smoking habit) after the diagnosis is made. Such changes can alter lipid risk factor levels and obscure etiologic risk factor associations with the presence of coronary artery disease. It is therefore preferable to determine the contribution of potential risk factors before the diagnosis of coronary artery disease has been established. In this trial, we used stress nuclear myocardial perfusion imaging to diagnose coronary artery disease in patients presenting for evaluation of chest pain. Two groups of age- and sex-matched patients were identified: a normal group (patients with no evidence of coronary artery disease), and an abnormal group (patients whose scans indicated the presence of significant coronary artery disease due to either fixed or reversible perfusion defects). Blood samples were drawn before scanning and analyzed for lipid risk factors. Compared to the normal group, the abnormal group had higher levels of triglycerides (189±91 vs. 135±51 mg/dL, p=0.003), lower levels of high density lipoprotein cholesterol (39±9 vs. 45±14 mg/dL, p=0.037), and higher levels of small, dense low density lipoprotein (LDL3) (42±18 vs. 32±13 mg/dL, p=0.007). Total cholesterol, low density lipoprotein, and lipoprotein(a) levels were similar between groups. These findings suggest that ischemic heart disease, as assessed by myocardial perfusion scintigraphy, is more closely associated with the low high density lipoprotein/high triglyceride syndrome than with increased low density lipoprotein or total cholesterol levels. [source]

Transthoracic Doppler Echocardiographic Coronary Flow Imaging in Identification of Left Anterior Descending Coronary Artery Stenosis in Patients with Left Bundle Branch Block

ECHOCARDIOGRAPHY, Issue 10 2008
Ozer Soylu M.D.
Background: Conventional noninvasive methods have well-known limitations for the detection of coronary artery disease (CAD) in patients with left bundle branch block (LBBB). However, advancements in Doppler echocardiography permit transthoracic imaging of coronary flow velocities (CFV) and measurement of coronary flow reserve (CFR). Our aim was to evaluate the diagnostic value of transthoracic CFR measurements for detection of significant left anterior descending (LAD) stenosis in patients with LBBB and compare it to that of myocardial perfusion scintigraphy (MPS). Methods: Simultaneous transthoracic CFR measurements and MPS were analyzed in 44 consecutive patients with suspected CAD and permanent LBBB. Typical diastolic predominant phasic CFV Doppler spectra of distal LAD were obtained at rest and during a two-step (0.56,0.84 mg/kg) dipyridamole infusion protocol. CFR was defined as the ratio of peak hyperemic velocities to the baseline values. A reversible perfusion defect at LAD territory was accepted as a positive scintigraphy finding for significant LAD stenosis. A coronary angiography was performed within 5 days of the CFR studies. Results: The hyperemic diastolic peak velocity (44 ± 9 cm/sec vs 62 ± 2 cm/sec; P=0.01) and diastolic CFR (1.38 ± 0.17 vs 1.93 ± 0.3; P=0.001) were significantly lower in patients with LAD stenosis compared to those without LAD stenosis. The diastolic CFR values of <1.6 yielded a sensitivity of 100% and a specificity of 94% in the identification of significant LAD stenosis. In comparison, MPS detected LAD stenosis with a sensitivity of 100% and a specificity of 29%. Conclusions: CFR measurement by transthoracic Doppler echocardiography is an accurate method that may improve noninvasive identification of LAD stenosis in patients with LBBB. [source]

Accuracy of single-detector spiral CT in the diagnosis of pulmonary embolism: a prospective multicenter cohort study of consecutive patients with abnormal perfusion scintigraphy

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 1 2005
M. J. L. VAN STRIJEN
Summary.,Background: Spiral computed tomography (CT) has emerged as a potentially conclusive diagnostic test to exclude pulmonary embolism (PE) in patients with non-high probability scintigraphy and is already widely used,sometimes as the sole primary diagnostic test in the diagnosis of suspected PE. Its true sensitivity and specificity has, however, not been evaluated previously in a large cohort of consecutive patients. Methods: In a multicenter prospective study 627 consecutive patients with clinically suspected PE were studied. Patients with normal perfusion scintigraphy were excluded from further analysis. Single-detector spiral CT scanning and ventilation scintigraphy were then performed in all patients to diagnose PE, while pulmonary angiography was performed as the gold standard. The only exceptions were those patients who had both a high-probability VQ scan and a CT scan positive for PE: these patients were considered to have PE and did not undergo additional pulmonary angiography. All imaging tests were read by independent expert panels. Results: Five hundred and seventeen patients were available for complete analysis. The prevalence of PE was 32%. Spiral CT correctly identified 88 of 128 patients with PE, and 92 of 109 patients without PE, for a sensitivity and specificity of 69%[95% confidence interval (CI) 63,75] and 84% (95% CI 80,89), respectively. The sensitivity of spiral CT was 86% (95% CI 80,92) for segmental or larger PE and 21% (95% CI 14,29) in the group of patients with subsegmental PE. Conclusion: The overall sensitivity of spiral CT for PE is too low to endorse its use as the sole test to exclude PE. This holds true even if one limits the discussion to patients with larger PE in segmental or larger pulmonary artery branches. We conclude that, in patients with clinically suspected PE and an abnormal perfusion scintigraphy, single-slice detector spiral CT is not sensitive enough to be used as the sole test to exclude PE. [source]

Exercise- or dipyridamole-loaded QGS is useful to evaluate myocardial ischemia and viability in the patients with a history of Kawasaki disease

PEDIATRICS INTERNATIONAL, Issue 5 2005
Yuichi Ishikawa
AbstractBackground:,Evaluation of myocardial ischemia and viability is very important for the management of patients with a history of Kawasaki disease (KD). 99mTc-tetrofosmin myocardial perfusion scintigraphy combined with quantitative gated single photon computed emission tomography (QGS) gives us information, not only about perfusion, but also the percentage change in left ventricular wall thickness (%WT) and relative changes in left ventricular wall motion (LVM). Methods:,The subjects were 27 patients with a history of KD followed as outpatients at the National Cardiovascular Center, Osaka, Japan. Exercise-loaded QGS was performed on 21 patients, and dipyridamole- loaded QGS was performed in six patients younger than 7 years old. Results:,Perfusion defects (PD) were observed in 12 patients. Of the 12 patients, four with old myocardial infarction (OMI) had decreased %WT. All patients with OMI showed a decrease in %WT in the areas where PD was seen on the image. The other eight patients without OMI showed no decrease in %WT. In non-infarcted cases, the %WT was normal in the PD-positive area. Conclusions:,It is possible to evaluate myocardial ischemia and viability in KD patients by comparing PD on the image with %WT determined by QGS using exercise or drug-loaded myocardial scintigraphy alone. [source]

Lipid Risk Factor Correlates of Ischemic Heart Disease as Diagnosed by Myocardial Perfusion Scintigraphy

The Effect of Myocardial Surgical Revascularization on Left Ventricular Late Potentials

ANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 2 2001
Levent Can M.D.
Background: The presence of ventricular late potentials (LP) is an important indicator for the development of ventricular tachyarrhythmias due to ischemic heart disease. The effect of myocardial revascularization on LP has remained controversial. The purpose of this study was to determine whether complete myocardial surgical revascularization (CABG) documented by myocardial perfusion scintigraphy might alter the substrate responsible for LP. Methods: Prospectively, enrolled patients undergoing elective CABG were evaluated with thallium-201 myocardial perfusion scintigraphy and signal- averaged ECG pre- and postoperatively. SAECG recordings were obtained serially: before, 48,72 hours and 3 months after CABG. LPS were defined as positive if SAECG met at least two of Gomes criteria. Scintigraphies were performed pre-and 3 months postoperatively for determination of the success of revascularization. Changes observed in SAECG recordings after CABG were compared between those with and without successful revascularization. Results: CABG resulted in successful revascularization in 23 patients and was unsuccessful in 17 (no change or deterioration of the perfusion defects). Preoperative SAECG values were not different between groups except for RMS values. The incidence of LP decreased significantly postoperatively in patients with improved myocardial perfusion, whereas there were no changes in patients who did not have postoperative perfusion improvement (McNemar test, P < 0.05). Conclusions: LPs disappear following the elimination of myocardial ischemia by complete surgical revascularization. Persistence of ischemia following CABG usually results in the persistence of late potentials. The incidence of ventricular arrhythmias is expected to be unchanged in these patients and they should be reevaluated for reinterventions. A.N.E. 2001;6(2):84,91 [source]

A double-blind study on a patient with tardive dyskinesia treated with pallidal deep brain stimulation

ACTA NEUROLOGICA SCANDINAVICA, Issue 4 2009
Z. Kefalopoulou
Background,,, Tardive dyskinesia (TD) is a neurological disorder typically induced by long-term exposure to neuroleptics. Deep brain stimulation (DBS) of the globus pallidus internus (GPi) may represent a therapeutic alternative for TD, which is often resistant to conservative treatment. Aims of the study,,, This report's objective is to present a case of TD successfully treated with DBS, as well as to indicate a putative role of brain perfusion scintigraphy as a helpful tool correlating functional imaging findings with clinical responsiveness to DBS. Methods/Results,,, A 42-year-old male patient suffering from refractory TD underwent bilateral GPi DBS surgery. Post-operative Burke-Fahn-Mardsen Dystonia Rating Scale (BFMDRS) and Abnormal Involuntary Movement Scale (AIMS) total scores have been reduced by 90.7% and 76.7% respectively on the 6-month follow-up assessment. Brain perfusion scintigraphy, performed post-operatively in the two stimulation states, revealed a decrease in cerebral blood flow, during the ,on-DBS', compared with the ,off-DBS' state. Conclusions,,, Clinical improvement of this patient, correspondent to previous studies, suggests that continuous bilateral GPi DBS may provide a promising treatment option for TD. Furthermore, this report could imply, as no previous such comparison study exists, a possible correlation between brain functional imaging findings and the movement disorder's response to DBS. [source]

Validation of a new automated method for analysis of gated-SPECT images

CLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 3 2006
Milan Lomsky
Summary We recently presented a new method for quantification of CArdiac FUnction , denoted CAFU , as the first step in the development of an automated method for integrated interpretation of gated myocardial perfusion single photon emission computed tomography (SPECT) images. The aim of this study was to validate CAFU in the assessment of global and regional function of the left ventricle. Quantitative gated-SPECT (QGS), the most widely used software package for quantification of gated-SPECT images, was used as reference method for the measurements of ejection fraction (EF) and ventricular volumes, and visual analysis by an experienced physician was used as reference method for the measurements of regional wall motion and thickening. Two different groups of consecutive patients referred for myocardial perfusion scintigraphy were studied. Global function was evaluated in 316 patients and regional function in 49 other patients. The studies were performed using a 2-day stress/rest 99 m-Tc-sestamibi protocol. A good correlation was found between EF values from QGS and CAFU (EF CAFU = 0·84 EF QGS + 13, r = 0·94), but CAFU values were on average 4 EF points higher than QGS values. With CAFU the segments with normal thickening according to the physician showed significantly higher thickening values (in all parts of the myocardium) compared to the segments classified as having abnormal thickening. In conclusion, this study demonstrates that CAFU can be used to quantify global and regional function in gated-SPECT images. This is an important step in our development of an automated method for integrated interpretation of gated-SPECT myocardial perfusion scintigraphy studies. [source]

Patient gender and radiopharmaceutical tracer is of minor importance for the interpretation of myocardial perfusion images using an artificial neural network

CLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 3 2006
Kristina Tägil
Summary The purpose of this study was to assess the influence of patient gender and choice of perfusion tracer on computer-based interpretation of myocardial perfusion images. For the image interpretation, an automated method was used based on image processing and artificial neural network techniques. A total of 1000 patients were studied, all referred to the Royal Brompton Hospital in London for myocardial perfusion scintigraphy over a period of 1 year. The patients were randomized to receive either thallium or one of the two technetium tracers, methoxyisobutylisonitrile or tetrofosmin. Artificial neural networks were trained with either mixed gender or gender-specific and mixed tracer or tracer-specific training sets of different sizes. The performance of the networks was assessed in separate test sets, with the interpretation of experienced physicians regarding the presence or absence of fixed or reversible defects in the images as the gold standard. The neural networks trained with large mixed gender training sets were as good as the networks trained with gender-specific data sets. In addition, the neural networks trained with large mixed tracer training sets were as good as or better than the networks trained with tracer-specific data sets. Our results indicate that the influence of patient gender and perfusion tracer are of minor importance for the computer-based interpretation of the myocardial perfusion images. The differences that occur can be compensated for by larger training sets. [source]

Incidence of venous thromboembolism following major abdominal surgery: a multi-center, prospective epidemiological study in Japan

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 3 2006
M. SAKON
Summary.,Background:,Venous thromboembolism (VTE) has been considered to be a rare surgical complication in Japan. Aim:,To investigate the incidence and risk factors of VTE in Japanese patients undergoing major abdominal surgery. Methods:,A prospective, multi-center epidemiological study was conducted from December, 2001 to August 2002 in 39 medical institutes throughout Japan. A total of 173 patients with general (n = 128), gynecologic (n = 23), and urologic (n = 22) surgery were analyzed. For the diagnosis of deep vein thrombosis (DVT), bilateral venography was performed in all patients. Lung ventilation/perfusion scintigraphy was carried out in patients suspected of pulmonary thromboembolism (PTE). Results:,There were 36 patients with distal DVT (20.8%) and five patients with proximal DVT (2.9%). One patient was diagnosed as PTE. Overall, VTE was diagnosed in 42 patients (24.3%). By univariate analysis, only age (60 years or older) was identified as a significant risk factor in the whole study population. When analyzed by the stepwise multiple logistic regression model, female gender, operation site, age, and operation time were four risk factors found to be significant. The incidence of VTE was closely related to the number of risk factors that patients had. As many as 44% of patients with three or four risk factors developed VTE while those with one or two risk factors showed about a 17% incidence of VTE. Four patients lacking any risk factors did not develop VTE. Conclusions:,Venous thromboembolism is common in Japanese patients undergoing major abdominal surgery. Pharmacologic thromboprophylaxis is considered essential, particularly in those patients with multiple, potential risk factors. [source]

Diagnostic evaluation of planar and tomographic ventilation/perfusion lung images in patients with suspected pulmonary emboli

CLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 5 2004
Marika Bajc
Summary Planar lung ventilation/perfusion scintigraphy (V/PPLANAR) is a standard method for diagnosis of pulmonary embolism (PE). The goals of this study were to test whether the diagnostic information of ventilation/perfusion tomography (V/PSPET) applied in clinical routine might enhance information compared with V/PPLANAR and to streamline data processing for the demands of clinical routine. This prospective study includes 53 patients suspected for PE referred for lung scintigraphy. After inhalation of 99mTc-DTPA planar ventilation imaging was followed by tomography, using a dual-head gamma camera. 99mTc-MAA was injected i.v. for perfusion tomography followed by planar imaging. Patients were examined in supine position, unchanged during V/P tomography. Two reviewers evaluated V/PPLANAR and V/PSPET images separately and randomly. Mismatch points were calculated on the basis of extension of perfusion defects with preserved ventilation. Patients were followed up clinically for at least 6 months. With V/PSPET the number of patients with PE was higher and 53% more mismatch points were found. In V/PSPET interobserver variation was less compared with V/PPLANAR. Ancillary findings were observed by both techniques in half of the patients but more precisely interpreted with V/PSPET. V/PSPET shows more and better delineated mismatch defects, improved quantification and less interobserver variation compared with V/PPLANAR. V/PSPET is amenable to implementation for clinical routine and suitable even when there is demand for a high patient throughput. [source]