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

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

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

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

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

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

PURPOSE: This study was performed to investigate the clinical significance of reverse redistribution (RR) phenomenon detected on delayed Tc-99m tetrofosmin myocardial single photon emission computed tomography (SPECT) in patients with acute myocardial infarction after revascularization. MATERIALS AND METHODS: A Tc-99m tetrofrosmin myocardial SPECT was performed in 67 consecutive patients after revascularization for acute myocardial infarction. Myocardial SPECT imaging was performed for early imaging at 40 min and for delayed imaging at 180 min after reinjection at myocardial stress. Regional myocardial uptakes were scored by 4-point scoring in the left ventricular wall divided into 17 segments. Reverse redistribution was defined as an increase of more than 2 point in the activity score on the delayed image. Follow-up myocardial SPECT and coronary angiography (CAG) were performed 9 months later. RESULTS: On myocardial SPECT performed following revascularization, RR was observed in 100 of all 319 segments (31%) and in 43 patients (64%). The abnormalities of perfusion and regional wall motion were more severe in the patients with RR compared to those without RR (p<0.05). On follow-up myocardial SPECT, the myocardial perfusion, regional wall motion, and myocardial thickness were significantly improved in the patients with RR (p<0.05) however, these changes were not significant in those without RR. There was no significant difference between the patients with RR and those without RR in the occurrence of restenosis on CAG. CONCLUSIONS: In patients with acute myocardial infarction, the regions showing the RR phenomenon on delayed Tc-99m tetrofosmin SPECT may reflect viable myocardium and indicate recovery of salvaged myocardium.
Angioplasty ; Coronary Angiography ; Follow-Up Studies ; Humans ; Myocardial Infarction ; Myocardial Perfusion Imaging ; Myocardium ; Perfusion ; Tomography, Emission-Computed, Single-Photon

MRI has achieved many technical advances in the spatial resolution, temporal resolution, contrast resolution, signal-to-noise ratio, and postprocessing technique. At one session of examination within a tolerable time, MRI can provide integrated information on coronary artery stenosis, systolic dysfunction, myocardial perfusion, and myocardial viability. Delayed enhancement study after contrast administration is highly reproducible and offers unique vision for myocardial viability in the patients with myocardial infarction. Cardiac MRI is very cost-effective and may be one-stop solution for the evaluation of ischemic heart disease.
Coronary Stenosis ; Humans ; Magnetic Resonance Imaging* ; Myocardial Infarction ; Myocardial Ischemia* ; Perfusion ; Signal-To-Noise Ratio