The integrative value of myocardial perfusion-function imaging with 13N-ammonia positron emission tomography:From methodology to clinical impact

The current profile of cardiovascular disease is a source of concern due to its prevalence and the substantial burden of its associated outcomes. Although advances in cardiac therapy represent a great contribution in this area, there is a need for better and more integral methods to diagnose and evaluate prognosis in patients with heart disease. Within these novel state-of-the-art methods, the present thesis studied the utilization of positron emission tomography (PET) imaging using 13N-ammonia (an injectable tracer that allows us to picture blood flow in the coronary arteries). By exploring alternatives in methodological aspects of this technique as well as how blood flow and heart motion relate to each other in different groups of patients, we propose that further integration of clinical data and data obtained through PET should be considered when characterizing heart disease. We confirmed the relevant influence of diabetes mellitus as a risk factor that affects not only heart blood flow but heart motion as well. In the near future, the combination of measurements obtained by cardiac PET imaging may optimize risk stratification as they already translate an elevated risk of fatal outcomes individually

The utilization of positron emission tomography in the evaluation of renal health and disease

Purpose: Positron emission tomography (PET) is a nuclear imaging technique that uses radiotracers to visualize metabolic processes of interest across different organs, to diagnose and manage diseases, and monitor therapeutic response. This systematic review aimed to characterize the value of PET for the assessment of renal metabolism and function in subjects with non-oncological metabolic disorders. Methods: This review was conducted and reported in accordance with the PRISMA statement. Research articles reporting “kidney” or “renal” metabolism evaluated with PET imaging between 1980 and 2021 were systematically searched in Medline/PubMed, Science Direct, and the Cochrane Library. Search results were exported and stored in RefWorks, the duplicates were removed, and eligible studies were identified, evaluated, and summarized. Results: Thirty reports met the inclusion criteria. The majority of the studies were prospective (73.33%, n = 22) in nature. The most utilized PET radiotracers were 15O-labeled radio water (H215O, n = 14) and 18F-fluorodeoxyglucose (18F-FDG, n = 8). Other radiotracers used in at least one study were 14(R,S)-(18)F-fluoro-6-thia-heptadecanoic acid (18F-FTHA), 18F-Sodium Fluoride (18F-NaF), 11C-acetate, 68-Gallium (68Ga), 13N-ammonia (13N-NH3), Rubidium-82 (82Rb), radiolabeled cationic ferritin (RadioCF), 11C‐para-aminobenzoic acid (11C-PABA), Gallium-68 pentixafor (68Ga-Pentixafor), 2-deoxy-2-F-fluoro-d-sorbitol (F-FDS) and 55Co-ethylene diamine tetra acetic acid (55Co-EDTA). Conclusion: PET imaging provides an effective modality for evaluating a range of metabolic functions including glucose and fatty acid uptake, oxygen consumption and renal perfusion. Multiple positron emitting radiolabeled racers can be used for renal imaging in clinical settings. PET imaging thus holds the potential to improve the diagnosis of renal disorders, and to monitor disease progression and treatment response

Stress myocardial blood flow correlates with ventricular function and synchrony better than myocardial perfusion reserve:A Nitrogen-13 ammonia PET study

Cardiac PET quantifies stress myocardial blood flow (MBF) and perfusion reserve (MPR), while ECG-gated datasets can measure components of ventricular function simultaneously. Stress MBF seems to outperform MPR in the detection of significant CAD. However, it is uncertain which perfusion measurement is more related to ventricular function. We hypothesized that stress MBF correlates with ventricular function better than MPR in patients studied for suspected myocardial ischemia. We studied 248 patients referred to a rest and adenosine-stress Nitrogen-13 ammonia PET. We performed a multivariate analysis using systolic function (left ventricular ejection fraction, LVEF), diastolic function (mean filling rate in diastole, MFR/3), and synchrony (Entropy) as the outcome variables, and stress MBF, MPR, and relevant covariates as the predictors. Secondarily, we repeated the analysis for the subgroup of patients with and without a previous myocardial infarction (MI). 166 male and 82 female patients (mean age 63 +/- 11 and 67 +/- 11 year, respectively) were included. 60% of the patients presented hypertension, 57% dyslipidemia, 21% type 2 diabetes mellitus, 45% smoking, and 34.7% a previous MI. Mean stress MBF was 1.99 +/- 0.75 mL/g/min, MPR = 2.55 +/- 0.89, LVEF = 61.6 +/- 15%, MFR/3 = 1.12 +/- 0.38 EDV/s, and Entropy = 45.6 +/- 11.3%. There was a significant correlation between stress MBF (P <.001) and ventricular function. This was stronger than the one for MPR (P = .063). Sex, age, diabetes, and extent of previous MI were also significant predictors. Results were similar for the analyses of the 2 subgroups. Stress MBF is better correlated with ventricular function than MPR, as evaluated by Nitrogen-13 ammonia PET, independently from other relevant cardiovascular risk factors and clinical covariates. This relationship between coronary vasodilatory capacity and ventricular function is sustained across groups with and without a previous MI

POR UNA CULTURA DE PAZ: UNA MIRADA DESDE LAS CIENCIAS DE LA CONDUCTA

En
 virtud
 de
 lo
 anterior,
 los
 estudiosos
 de
 las
 ciencias
 de
 la
 conducta
 
de
 la
 Universidad
Autónoma 
del
 Estado 
de 
México,

ante 
la
persistencia
 y 
proliferación
 de
 estos 
hechos
 en
 diversas
 partes
 del
Mundo
 y
 de
 nuestro 
país 
en 
particular, se
 convocó
 a
 los
 estudiosos
 interesados
 y
 a
 la
 sociedad
 en
 general
 a
 presentar
 trabajos
 para
 analizar,
 debatir
 y
 proponer
 estrategias
 de
 acción
 y
 dirección,
 que
 fortalezcan
 una
 convivencia y bienestar con sentido humanista para una cultura de paz. El
 presente
 texto
 es
 producto
 de 
esta convocatoria 
que
 recoge 
los
trabajos 
de 

los
 interesados 
en 
la
 temática,

 de
 diferentes 
países
(España,
Argentina,
Cuba,
Brasil,
Costa
 Rica
 y
 México)
 retomando
 con
 ello
 sus
 experiencias
 relativas
 al
 estudio,
 análisis,
 comprensión
 e
 instrumentación
 de
 la
 cultura
 de
 paz
 en
 los
 distintos
 ámbitos
 institucionales
 en
 los
 que
 participan:
 educativo,
 salud,
 penitenciario,
 social,
laboral,
familia,
alimentario,
psicológico,
por 
mencionar 
algunos.
 El
 presente
 libro,
 propicia
 un
 espacio
 de
 reflexión,
 diálogo
 y
 posicionamiento
 de
 las 
ciencias 
de 
la 
conducta
 para 
la 
apropiación,
análisis,
debate
 y 
propuestas 
que
 fortalezcan 
una
 cultura
 de 
paz
 a
través
 de 
la
 convivencia 
y
 el 
bienestar
 social 
con
 sentido 
humanista.
El
 sistema 
económico
 neoliberal
 y 
el 
proceso
 de 
globalización 
han
 contribuido
al
 logro
 de
 avances
 significativos
 en
 la
 ciencia
 y
 la
 tecnología,
 pero
 también
 han
 propiciado
 la
 polarización
 de
 las
 sociedades
 lo
 que
 ha
 impactado
 de
 manera
 negativa
 a
 la
 sociedad
 en
 su
 conjunto,
 pero
 en
 mayor
 medida
 a
 los grupos
 vulnerables. Dicha
 polarización
 ha
 traído
 consigo
 un
 desarrollo
 desigual
 del
 mundo
 que
 se
 expresa
 de
 diferentes
 maneras
 tanto
 en
 países
 desarrollados
 como
 en
 los
 llamados
 del
 tercer
 mundo,
 en
 donde
 no
 están
 satisfechas
 las
 necesidades
 humanas 
elementales
 de
 todos 
los
sectores 
de 
la 
población,
siempre 
falta 
algo. 
Si 
a
 esto 
le
 sumamos 
los
conflictos
 internacionales por
 diferentes
 motivos
 que
 enfrentan
 algunas
 naciones,
 una
 insuficiente
 cobertura
 educativa
 y
 de
 salud,

 desempleo
 y
 pobreza 
extrema,
 entre 
otras
 cosas; 
estamos
 frente
 a
retos 
de
 gran
 envergadura
 para
 los
 gobiernos,
 para
 los
 estudiosos
 y
 para
 la
 sociedad
 civil
 en
 general. Uno 
de 
los
 intentos
 para
 frenar 
y prevenir 
la
 agudización
 de 
estas 
problemáticas
 es
 la
 cultura 
de 
paz,
cuyo
 estudio
y propuestas 
han 
ido 
avanzando 
en 
diferentes
 sentidos 
y 
de 
manera 
favorable,
el 
tema 
está 
presente 
en 
diferentes 
Organismos
 Internacionales
 como
 la
 ONU,
 la
 UNESCO,
 la
 OCDE,
 El
 Banco
 Mundial,
 entre
 otros.
 Pero
 falta 
mucho 
por 
hacer.Universidad Autónoma del Estado de Méxic

Residual Activity Correction in Quantitative Myocardial Perfusion 13N-Ammonia PET Imaging: A Study in Post-MI Patients

Background/Introduction/Aim: Positron emission tomography (PET) is the gold standard for the quantification of myocardial blood flow (MBF). A standard PET scan is acquired in two phases (rest and pharmacological stress). 13N-ammonia is a perfusion radiotracer that may show residual activity, which may affect MBF estimation during the second phase of the scan. An algorithm for residual activity correction (RAC) is available when reconstruction is performed using Syngo MBF (by Siemens). The aim of this study was to evaluate differences in MBF estimation with and without RAC by Syngo MBF in patients with a previous MI using 13N-ammonia PET. Methods: MBF was evaluated by 13N-ammonia PET in a group of 25 patients with a history of MI. Dynamic MBF measurements were analyzed with Syngo Dynamic PET, with and without RAC, and the results were evaluated with statistical methods. Results: Significant differences in stress phase MBF after RAC were identified in the left anterior descending coronary artery (LAD) territory (p=0.0425) and the right coronary artery (RCA) territory (p=0.004). A trend towards significance was identified in the global polar plot (p=0.049). No statistically significant difference was found in the left circumflex artery (LCx) territory (p=0.333). Conclusion: Syngo Dynamic PET, through its RAC function, can be a useful adjunct in assessing second-phase MBF of primarily the RCA territory and secondarily the global polar plot and LAD territory but not the LCx territory

Medición experimental de la densidad de la nube de cavitación en un Slit Venturi

En el presente trabajo, se reporta la caracterización experimental de la formación y desarrollo de la nube de cavitación en diferentes temperaturas de líquido 20, 30, 40 y 50 °C. Para ello, se construyó una instalación hidráulica que tiene como elemento principal un tubo Venturi de sección rectangular, con ella, se generaron las condiciones de flujo necesarias para formar la cavitación y medir las propiedades termodinámicas para el cálculo de los números adimensionales de Thoma y Reynolds. El error promedio de sesgo de las mediciones no superó el 1%, por tal razón, se aseguró la buena calidad del cálculo en los números adimensionales de Thoma y Reynolds.  Con los números de Thoma “σ” y Re se caracterizaron las diferentes fases de la nube de cavitación, desde incipiente, cuasi, desarrollada y super cavitación en el rango de temperaturas del experimento, encontrando que el tránsito de la cavitación incipiente a desarrollada es más fácil a temperatura ambiente, ya que, el régimen de flujo aumentará solo 15.82% en comparación con las otras temperaturas. El inicio de la nube de cavitación depende de la viscosidad del fluido, en el intervalo de prueba la variación de la viscosidad fue de 55% por lo que el régimen de flujo será afectado por la viscosidad y por consiguiente en el inicio de la nube de gas. Finalmente, la densidad del fluido en el rango de temperatura de la prueba permaneció constante, ya que no vario más de 1%, por lo que no afectó al régimen de flujo