PURPOSE: The aim of this study is to better understand the pattern and nature of reverse redistribution (RR) in myocardial perfusion imaging. MATERIALS AND METHODS: In consecutive 20 acute myocardial infarction (MI) patients, frequency of RR was correlated with that of subendocardial MI that was detected by myocardial contrast echocardiography (MCE). RR was judged to be present when there was more than one grade of worsening in perfusion at 24 hr delayed images compared with the initial rest images. MCE evaluated the significant lack of opacification in the subendocardial myocardium relative to the subepi-cardial myocardium to suggest the subendocardial MI. Kendall's nonparametric correlation coefficiency was calculated. RESULTS: Concordant cases were 15 of 20 (75%) and correlation was statistically significant (p=0.0285). CONCLUSION: Our results suggested that RR was correlated with MCE-detected nontransmural MI.
Echocardiography* ; Humans ; Myocardial Infarction* ; Myocardial Perfusion Imaging ; Myocardium ; Perfusion

Scince 201Tl was introduced as a myocardial perfusion imaging agent in the early 1970s, scintigraphic evaluation of myocardial perfusion for the diagnosis of coronary artery disease is a valuable noninvasive diagnostic imaging modality. Stress radionuclide myocardial perfusion imaging is widely accepted to have high diagnostic and prognostic use in the assessment of patients with known or suspected coronary artery disease. With wise use of this nonivasive imaging technique, more patients are referred for stress perfusion imaging. Until now various protocols for stress testing and myocardial imaging were developed and used in worldwide. This article presented various protocols of stress testing and myocardial imaging for clinical use.
Coronary Artery Disease ; Diagnostic Imaging ; Exercise Test ; Humans ; Myocardial Perfusion Imaging ; Perfusion ; Perfusion Imaging

Contrast echocardiography is broadly described as a variety of techniques whereby the blood pool on cardiac ultrasound is enhanced with encapsulated gas-filled microbubbles or other acoustically active nano- or microparticles. The development of this technology has occurred primarily in response to the need improve current diagnostic applications of echocardiography such as the need to better define left ventricular cavity volumes, regional wall motion, or the presence or absence of masses and thrombi. A secondary reason for the development of contrast echocardiography has been to expand the capabilities of echocardiography. These new applications include myocardial perfusion imaging for detection of ischemia and viability, perfusion imaging of masses/tumors, and molecular imaging. The ability to fill all of these current and future clinical roles has been predicated on the ability to produce robust contrast signal which, in turn, has relied on technical innovation with regards to the microbubble contrast agents and the ultrasound imaging paradigms. In this review, we will discuss the basics of contrast echocardiography including the composition of microbubble contrast agents, the unique imaging methods used to optimize contrast signal-to-noise ratio, and the clinical applications of contrast echocardiography that have made a clinical impact.
Contrast Media ; Echocardiography* ; Ischemia ; Microbubbles ; Molecular Imaging ; Myocardial Perfusion Imaging ; Perfusion Imaging ; Signal-To-Noise Ratio ; Ultrasonography

Electrocardiography ; Humans ; Myocardial Infarction ; physiopathology ; Myocardial Perfusion Imaging ; methods

Tetrofosmin is a ligand that forms a lipophilic, cationic complex with Tc-99m.1) Tc-99m tetrofosmin was developed as a myocardial perfusion imaging agent and also used to depict tumors.1-3) Mediastinal tumors is also detected by Tc-99m tetrofosmin.2-5) We report a case of extracardiac mediastinal activity detected by Tc-99m tetrofosmin scintigraphy, which revealed thymoma.
Myocardial Perfusion Imaging ; Thymoma ; Tomography, Emission-Computed, Single-Photon

BACKGROUND: The effect of right ventricular pacing on myocardial perfusion and regional wall motion is not well known, although some studies have suggested that it may be adverse. We investigated the effects of right ventricular pacing on myocardial perfusion and regional wall motion in patients with permanent pacemakers. METHOD: Thirty patients receiving permanent pacemakers for complete heart block or sick sinus syndrome were included in this study. All the patients showed normal coronary angiograms. Myocardial scintigraphy and two-dimensional echocardiography were performed to assess myocardial perfusion and to evaluate regional wall motion and global function of the left ventricle (LV). RESULTS: 1) Mean age was 66.2+/-8.2 (41-84) years, and the male-to-female ratio was 1 : 1.7 (11 male, 19 female). Indications for permanent pacemaker implantation were complete atrioventricular (AV) block in 21 patients and sick sinus syndrome in 9. The selected pacing modes were VVI in 14 patients, DDD in 8, VDD in 6, and AAI in 2. LV ejection fraction estimated by 2-dimensional echocardiography was 62.7+/-5.8 (53-86)%. 2) Perfusion defects were noted in 26 (87%) patients including 25 (89%) out of 28 patients with ventricular pacing modes such as VVI, DDD, and VDD, and 1 (50%) out of 2 patients with AAI mode. Locations of perfusion defects were septal in 19 (63%) patients, inferior in 17 (57%), apical in 16 (53%), lateral in 3 (10%), and anterior in 2 (7%). Extent of maximal perfusion defects was 17.0+/-9.5 (0-44)%. 3) Regional wall motion abnormalities were noted mainly over the apical region of the LV in 26 (93%) of 28 patients with ventricular pacing. However, LV ejection fraction did not differ significantly before and early after implantation of the pacemaker (62.7+/-5.8% vs. 61.0+/-5.8%, p-0.313). CONCLUSIONS: Right ventricular apical pacing frequently caused myocardial perfusion defects and regional wall motion abnormalities. These might be due to abnormal ventricular activation and abnormal interventricular septal motion. The long-term effects of these abnormalities remain to be determined, and the pacing technique to minimize these adverse effects should be developed.
Dichlorodiphenyldichloroethane ; Echocardiography ; Heart Block ; Heart Ventricles ; Humans ; Male ; Myocardial Perfusion Imaging ; Perfusion* ; Sick Sinus Syndrome

Positron emission tomogrpahy (PET) represents the most advanced scintigraphic imaging technology. With the increase in availability of PET, the clinical use of PET has grown in medical fields. This can be employed for cardiovascular research as well as for clinical applications in patients with various cardiovascular disease. PET allows non-invasive functional assessment of myocardial perfusion, substrate metabolism and cardiac innervation and receptors as well as gene expression in vivo. PET is regarded as the gold standard for the detection of myocardial viability, and it is the only method available for the quantitative assessment of myocardial blood flow. This review focuses on the clinical applications of myocardial perfusion PET in coronary artery disease.
Cardiovascular Diseases ; Coronary Artery Disease ; Gene Expression ; Humans ; Myocardial Perfusion Imaging ; Perfusion ; Positron-Emission Tomography

BACKGROUND AND METHOD: Pharmacological coronary vasodilation induced by dipyridamole is often used in association with thallium-201 scintigraphy to evaluate the presence and prognostic significance of coronary artery disease(CAD). Although dipyridamole has traditionally been used for this purpose, it causes frequent side effect, which at times can be life-threatening. Moreover, dipyridamole dose not elicit maximal coronary vasodilation in a substantial number of patients receiving the usual i.v. dose. Adenosine is an endogenously produced compound that has significant effects as a coronary vasodilator and rapid onset action and extremely short half-life(<10 seconds). The safety and diagnostic accuracy of intravenous adenosine Tc-99m MIBI imaging were evaluated in 248 patients who were referred for evaluation of CAD; 51 of the patients underwent coronary angiography and 25 of those exercise Tc-99 MIBI imaging. Adenosine was infused intravenously at a dose of 0.14 mg/kg/body weight per minute for 6 min and MIBI was injected at 3 min. RESULTS: Adenosine induced a significant decrease in systolic(p<0.05) and diastolic(p<0.001) blood pressures as well as a significant increase in heart rate(p<0.001) and rate-pressure product(p<0.01). The PR interval was slightly prolonged(p-NS). The overall sensitivity, specificity and predictive accuracy for CAD detection was 85%, 82%, and 83%, respectively. The diagnostic accuracy for individual CAD was low in left circumflex CAD. The agreement of segmental perfusion on adenosine and exercise Tc-99 MIBI imaging was 92% (Kappa index-0.83, p<0.001). Side effects occurred in 84% of 248 patients. Flushing (47%), dyspnea(45%), chest pain(28%) and headache(28%) were common. ST depression> or =1.0mm occurred in 8% and lst-, 2nd- and 3rd-degree atrioventricular block in 7%, 4%, and 1%, respectively. Side effects were mostly mild and transient except in 3 patients in whom premature termination of adenosine infusion and treatment were necessary. Aminophylline was used in only two patients. CONCLUSION: Thus, these facts suggest that pharmacological coronary vasodilation with adenosine in conjuction with Tc-99m MIBI myocardial scintigraphy appears to be a feasible, safe and valuable test for the diagnosis of coronary artery disease, particulary in patients unable to exercise.
Adenosine* ; Aminophylline ; Atrioventricular Block ; Coronary Angiography ; Coronary Artery Disease* ; Coronary Vessels* ; Diagnosis ; Dipyridamole ; Flushing ; Heart ; Humans ; Myocardial Perfusion Imaging ; Perfusion Imaging* ; Perfusion* ; Radionuclide Imaging ; Sensitivity and Specificity ; Thorax ; Vasodilation

Computed tomography (CT)-based myocardial perfusion imaging (CTP)has been widely recognized as a one-station solution for the imaging of myocardial ischemia-related diseases. This article reviews the clinical scanning protocols,analytical methods,and research advances of CTP in recent years and briefly discusses its limitations and future development.
Humans ; Myocardial Ischemia ; diagnostic imaging ; Myocardial Perfusion Imaging ; Myocardium ; Prospective Studies ; Tomography, X-Ray Computed

Though exercise T1-201 myocardial perfusion-scintigraphy is an important test in the diagnosis and evaluation of coronary artery disease, this test is limited in cases with poor physical conditions and unstable angina and the physical characteristics of thallium are not ideal for nuclear imaging of the myocardium. Recently, technetium-99m-labelled agent(99mTc-MIBI) has been developed to improved the quality of imaging and for easy usage in myocardial perfusion scan. Therefore, we performed dipyridamole 99mTc-MIBI myocardial scintigraphy and coronary angiography on 25 subjects who were suspeced to have coronary artery disease and the results obtanined were as follows ; 1) The overall diagnostic sensitivity of dipyridamole 99mTc-MIBI perfusion scintigraphy was 73.4%, while specificity was 66.7%. 2) Per vessel sensitivity for coronary artery disease diagnosis by the test was 71.4% and a per vessel specificity for coronary artery disease was 95.7%. 3) In all 75 coronary arteries, LAD had a sensitivity of 66.7%(10/15) and a specificity of 100%(10/10); RCA had a sensitivity of 75%(6/8) and a specificity of 82.4%(14/17); LCX had a sensitivity of 60%(3/5) and a specificity of 100%(20/20). 4) After infusion of dipyridamole, the most frequent adverse effect was chest pain which was seen in 8 cases(32%). The headache was seen in 7 cases(28%). Most of the symptoms were mild in severity and subsided spontaneously but 3 subjects were severe enough to require intravenous administration of aminophylline. In conclusion, dipyridamole 99m2011-06-17Tc-MIBI myocardial perfusion scintigraphy is a useful and safe test for diagnosis of coronary artery disease.
Administration, Intravenous ; Aminophylline ; Angina, Unstable ; Chest Pain ; Coronary Angiography ; Coronary Artery Disease* ; Coronary Vessels* ; Diagnosis ; Dipyridamole* ; Headache ; Myocardial Perfusion Imaging* ; Myocardium ; Perfusion ; Perfusion Imaging ; Sensitivity and Specificity ; Thallium