Tomografía computada multidetector de arterias coronarias: estado del arte. Parte II: Aplicaciones clínicas / Multidetector computed tomography of coronary arteries: state of the art. Second part: clinical applications

At the beginning of the evaluation of Coronary Artery Disease (CAD), Coronary Multidetector Computed Tomography (MDCT) was exclusively used to detect calcified plaques in coronary arteries through the Calcium Score, whose value by itself is limited. Nowadays, thanks to the technological advancements, potential clinical applications, with this method, include detection of coronary arterial stenosis, assessment of coronary bridges, and evaluation of anomalous coronaries. The intraluminal coronary stent evaluation is not possible yet, but this might become possible with the new-generation scanners. At the moment, the published results seem to be promising, nonetheless, the enthusiasm generated by this method should be accompanied by adequate training, as well as by its validation and certification.

Estudio de la función endotelial mediante tomografía por emisión de positrones en pacientes con hipercolesterolemia / Endothelial function assessment by positron emission tomography in patients with hypercholesterolemia

Hypercholesterolemia prompts to endothelial dysfunction (ED) and ED predisposes to atherogenesis. ED appears early in the course of atherogenesis and it is considered a coronary artery disease (CAD) marker. OBJECTIVES: To assess endothelial function (EF) using Positron Emission Tomography (PET) in asymptomatic patients with recent dyslipidemia diagnosis and without history of ischemic heart disease and previous hypolipemiant treatment. MATERIAL AND METHODS: Fourteen asymptomatic patients with recent dyslipidemia diagnosis (< 6 months) were studied by obtaining a lipid profile, blood glucose, and a three phase 13N-ammonia PET scan: rest, cold pressor test (CPT) and pharmacologic stress with adenosine. EF was assessed by calculating the coronary flow reserve (CFR), endothelial-dependant vasodilatation index (EDVI), and coronary blood flow increase percentage in CPT (% Delta CF). RESULTS: 79% of patients with dyslipidemia had ED and all their values were lower than those previously published as normal: rest coronary flow 0.44 +/- 0.12 vs 0.57 +/- 0.147 (p = 0.002), CPT coronary flow 0.57 +/- 0.17 vs 0.88 +/- 0.26 (p = 0.001), stress coronary flow 1.24 +/- 0.05 vs 1.81 +/- 0.35 (p = 0.005), EDVI 1.28 +/- 0.25 vs 1.53 +/- 0.24 (p 0.017), CRF 2.79 +/- 0.94 vs 3.15 +/- 0.48 (p 0.198) and % Delta CF 29.08 +/- 24.62% vs 53 +/- 24.60% (p 0.022). Conclusions: Asymptomatic patients in early stages of dyslipidemia showed a greater ED prevalence that was detected by 13N-ammonia PET scan.

Modelo de estudio mediante microPET para la evaluación del metabolismo glucolítico en el miocardio de rata con 18F-FDG. Experiencia inicial en México / A method designed for the assessment of myocardial metabolism in rats with 18F-FDG using small-animal-PET. Initial experience in Mexico

PURPOSE: To standarize an acquisition protocol for the study of myocardial metabolism in adult rats. MATERIAL AND METHODS: Three Wistar adult male rats were studied in three different protocols: no fasting group, fasting group over a period of 12 hr before the study with only water provided ad libitum, and fasting group by the same time receiving an oral 50% glucose solution. Thirty-minute acquisition images were obtained with a micro-PET, thirty and sixty minutes after the administration of 370-555 MBq 18F-FDG. Comparative and visual analysis were performed by two experts in the field. RESULTS: Eigtheen studies were analyzed, six per group. The best images were those of the first group, especially those taken at 60 minutes after the 18F-FDG administration. CONCLUSION: It is possible to establish the non-fasting protocol for the assessment of myocardial metabolism to be used in the future for the myocardial viability evaluation in ischemic cardiopathy.