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Background: Chagas’ disease is a serious problem in Latin America. Clinical settings where is managed might be limited; therefore simple diagnostic tools are needed to improve detection. Goldberger's electrocardiographic triad (SV1 or SV2 + RV5 or RV6 ≥ 3.5 mV, total QRS amplitude in limb leads

Erick Alexanderson Rosas,* Aloha Meave Gonzalez, and Moises Jimenez-Santos Departamento de Cardiologia Nuclear, Division de Imagen Cardiovascular No Invasiva, Instituto Nacional de Cardiologia ‘‘Ignacio Chavez’’, Mexico City, Mexico Departamento de Resonancia Magnetica y Tomografia Cardiaca, Division de Imagen Cardiovascular No Invasiva, Instituto Nacional de Cardiologia ‘‘Ignacio Chavez’’, Mexico City, Mexico Unidad PET/CT Ciclotron, Facultad de Medicina, Universidad Nacional Autonoma de Mexico, Mexico City, Mexico

Background: PET myocardial perfusion allows myocardial perfusion reserve (MPR) quantification as well as left ventricular ejection fraction (LVEF) and synchrony estimation through phase analysis. There is a relationship between MPR and LVEF and both have proven prognostic value in coronary artery disease (CAD). A relation between angiographic CAD extent and post-stress synchrony has been proposed with SPECT. We used 13N-ammonia PET to evaluate the relationship between MPR and ventricular synchrony in patients with a previous infarction and secondarily, to compare it to the relation MPR-LVEF. Methods: We studied 63 patients (64.4±11.1years) with a previous myocardial infarction with a rest/adenosine-stress 13N-ammoniaPET. Demographics and cardiovascular history were retrieved. MPR was calculated dividing the stress by the rest blood flow. Synchrony was evaluated through Entropy, systolic function through LVEF and the area of previous infarction through the resting total perfusion defect (TPD). Two multiple regressions were done: the first used Entropy as dependent variable and MPR, TPD and clinical variables as predictors; in the second LVEF replaced the dependent variable. The standardized regression coefficients were compared. Results: There were 49 males and 14 females, 39% with diabetes, 54% with hypertension, 54% with dyslipidemia, 42% of smokers and 44% with chest pain. Mean MPR=2.14±0.79, mean TPD=15.8%±11.2, mean LVEF=49%±17 and mean Entropy=53.4%±11.8. The first regression showed a significant independent relation between MPR and Entropy (β=-.384, p=0.006). This relation was greater than the one between MPR and LVEF (β=.292, p=0.013) in the second regression. In both, TPD (p=0.021, p=0.001) and gender (p=0.041, p=0.001) showed a significant correlation with the dependent variables. Conclusions: In patients with a previous myocardial infarction, PET-measured MPR significantly correlates to ventricular synchrony independently from the area of infarction. This correlation is stronger than the one between MPR and LVEF. Our results warrant further research into the added prognostic value of PET-measured ventricular synchrony and entropy in the setting of CAD.

The study of patients with coronary artery disease by means of gated SPECT has been well established. One of the major limitations of this technique is the detection of myocardial perfusion defects in the presence of multivessel or three-vessel coronary artery disease due to balanced ischemia. Quantification of myocardial blood flow by positron emission tomography allows not only to study cardiac perfusion and function but also to determine the coronary flow reserve which has a better correlation with significant stenosis in patients with trivascular disease. The aim of this study was to demonstrate through a case report and literature review the importance of performing quantification of coronary blood flow in this group of patients.

To evaluate the role of PET and MRI fused image study inpatients with primary brain tumors previously treated, to determine the presence of radionecrosis vs residual tumor viability.Primary brain tumors were diagnosed by biopse and MR. 18FDG-PET scan and T1 enhanced MRI follow-up studies were performed between 3 and 5 months after treatment. The 18F-FDG uptake was semiquantitavively calculated by a region-of-interest based Tumor hotspot/normal brain tissue index.Fifty-seven patients were studied, 37 had high grade gliomas; 9 had oligoastrocytomas; 5 had Embrionary tumors; I had a meningyoma and I had an oliodendroglial tumor. All MR studies showed tumor enhancement, without determine wether if it was radionecrosis or tumor viability. PET/MR fused study diagnosed 21 negative studies (30%) and 36 positive results (70%). Tumor hotspot/normal brain tissue index correlated well with the visual analysis registered.Visual analysis in the contrast enhanced MR overestimates the tumoral area, without defining a possible diagnosis between tumor viability and radionecrosis. Metabolic activity in the 18F-FDG PET study in the enhanced area, determines the presence of residual tumor viability. Therefore, coregistration can be used to obtain a more specific diagnosis optimizing the cinical use.

Lung carcinoma is one on the leading causes of death from cancer in all parts of the world. The frequency of this tumor is increasing; at present, accounts for approximately 25% of all cancer deaths. The majority of lung cancers are initially detected on chest radiographs, but many benign lesions have radiologic characteristics similar to malignant lesions. Computed tomography (CT) is most frequently used to provide additional anatomic and morphologic information on lesions, but it is limited in distinguishing between benign and malignant abnormalities. Fluorodeoxyglucose-Positron emission tomography (PET-FDG) imaging provides physiologic and metabolic information that characterizes lesions indeterminate by CT, is used clinically to-differentiate benign from malignant focal pulmonary abnormalities, to stage mediastinal and extrathoracic metastases, and to identify recurrence. It is the gold standard that define the therapeutic strategy.

The mean goal in the evaluation of a patient with coronary artery disease is the identification of patients at high risk to develop major cardiac events, including mortality. Ischemic patients can be stratified using non-invasive and invasive methods. Invasive procedures have some disadvantages, especially in follow-up studies. Nuclear Cardiology procedures, such as perfusion studies performed with thallium or 99mTc labeled agents (sestamibi, tetrofosmin), radioventriculography for right and left ventricle function evaluation and Gated SPECT are considered the best non-invasive procedures not only for the diagnosis of myocardial ischemia but for risk stratification. These techniques can identify the group of patients at high risk to develop major cardiovascular events, constituted by patients with perfusion abnormalities, specially during stress and systolic left ventricle dysfunction.

Positron emission tomography (PET) offers the unique capability of measuring non-invasive by the regional myocardial substrate flow and the biochemical reaction index in millimol per minute per gram of myocardial tissue. PET also allows for the assessment or quantification of regional myocardial blood flow, cardiac metabolism, ventricular function, myocardial viability, as well as autonomous nervous system, research and evaluating of dilated myocardiopathy and of ventricular hypertrophy. PET's success is based on the radioisotopes properties, their very short half-life allows for the administration of large doses.

The goal of myocardial viability assessment is to differentiate, prospectively, patients with potentially reversible from irreversible left ventricular dysfunction. Ideally, this information should be used to guide therapeutic decisions for revascularization. Therapeutic interventions that improve non functioning but viable myocardial regions may improve significantly global left ventricular function as well as impact left ventricular dysfunction, in which revascularization entails high perioperative morbidity and mortality. Accurate assessment of myocardial viability may result in more appropriate utilization of resources and enhance efficiency in health care delivery. Myocardial viability can be valorated with perfusion images using dual method or tallium reinjection, isotopic ventriculography, Gated SPECT with dobutamine stress or cardiac metabolism with PET.

Thrombolysis in ST Elevation Acute Myocardial Infarction in combination with novel antiplatelet agents has not been studied, it is not adressed in the guidelines and risks are actually unkown. We report the case of a 64 year old patient who was admitted to the National Institute of Cardiology of

Objectives The aim of this study was to use coronary computed tomographic (CT) angiography to characterize coronary artery involvement in patients with known Takayasu arteritis who present with anginal chest pain or shortness of breath. Background Takayasu arteritis is a primary vasculitis of the large vessels, which mainly affects the aorta and its branches but can also involve the coronary arteries. Coronary CT angiography allows visualization of the coronary vessels and can be used to detect both stenotic and nonstenotic coronary artery lesions. Methods Eighteen consecutive patients with Takayasu arteritis and angina (typical or atypical) and/or dyspnea underwent contrast-enhanced 64-slice coronary CT angiography. The arterial injury was classified according to the Numano classification. Three patients had prior known coronary artery disease. Coronary arteries were evaluated concerning the presence of obstructive and nonobstructive lesions, and differences between the clinical presentations of patients with and without coronary artery involvement on CT angiography were analyzed. Results Coronary artery involvement was found in 8 patients (44.4%), 3 of them with clinical activity. A total of 19 coronary lesions were present (13 in ostial locations, 5 in proximal coronary artery segments, and 1 in a mid segment). Eight lesions exceeded 50% diameter reduction (2 in ostial locations and 6 in proximal coronary artery segments). Median disease duration was significantly different between patients with coronary artery involvement (176 months; range 13 to 282 months) compared with those without (21 months; range 1 to 142 months) (p = 0.013). Conclusions Coronary CT angiography allows the assessment of coronary artery involvement in patients with Takayasu arteritis. These data confirm prior observations that most coronary lesions are in ostial or proximal coronary artery locations. Disease duration in patients with coronary artery involvement is longer than in patients without.

The prevalence of Myocardial Bridging (MB) has been found in 58% in Coronary Computed Tomography Angiography (CCTA), systolic compression and ischemia have been reported. The aim of this study was to describe the MB characteristics in CCTA and the presence of ischemia by Myocardial Perfusion Single

We investigated the relationship of quantitative plaque features from coronary CT Angiography (CTA) and coronary vascular dysfunction by impaired myocardial flow reserve (MFR) by 13N-Ammonia Positron Emission Tomography (PET). Fifty-one patients (32 men, 62.4±9.5 years) underwent combined rest