Opportunities for improvement on current nuclear cardiology practices and radiation exposure in Latin America: Findings from the 65-country IAEA Nuclear Cardiology Protocols cross-sectional Study (INCAPS).

BACKGROUND: Comparison of Latin American (LA) nuclear cardiology (NC) practice with that in the rest of the world (RoW) will identify areas for improvement and lead to educational activities to reduce radiation exposure from NC. METHODS AND RESULTS: INCAPS collected data on all SPECT and PET procedures performed during a single week in March-April 2013 in 36 laboratories in 10 LA countries (n = 1139), and 272 laboratories in 55 countries in RoW (n = 6772). Eight "best practices" were identified a priori and a radiation-related Quality Index (QI) was devised indicating the number used. Mean radiation effective dose (ED) in LA was higher than in RoW (11.8 vs 9.1 mSv, p < 0.001). Within a populous country like Brazil, a wide variation in laboratory mean ED was found, ranging from 8.4 to 17.8 mSv. Only 11% of LA laboratories achieved median ED <9 mSv, compared to 32% in RoW (p < 0.001). QIs ranged from 2 in a laboratory in Mexico to 7 in a laboratory in Cuba. Three major opportunities to reduce ED for LA patients were identified: (1) more laboratories could implement stress-only imaging, (2) camera-based methods of ED reduction, including prone imaging, could be more frequently used, and (3) injected activity of 99mTc could be adjusted reflecting patient weight/habitus. CONCLUSIONS: On average, radiation dose from NC is higher in LA compared to RoW, with median laboratory ED <9 mSv achieved only one third as frequently as in RoW. Opportunities to reduce radiation exposure in LA have been identified and guideline-based recommendations made to optimize protocols and adhere to the "as low as reasonably achievable" (ALARA) principle.

Determinación estadística de áreas cerebrales patológicas empleando tomografía por emisión de positrones / Statistical analysis of pathological brain areas using positron emission tomography

Los estudios de neuroimagen funcional permiten observar cuáles pueden ser las localizaciones de los diversos procesos neurofisiológicos que son la base de los procesos psicológicos como la memoria, atención, etc. Sin embargo, para un análisis científico y/o clínico de esta relación entre estructura y función es necesario desarrollar métodos de cuantificación que permitan la comprobación de las hipótesis planteadas empleando análisis estadísticos. En el presente trabajo presentamos un método que permite esta cuantificación y lo hemos comprobado tanto en un paciente como en un sujeto control. Los resultados obtenidos invitan a la aplicación del método tanto en estudios científicos como en la práctica clínica.

Functional neuroimaging studies allow knowing the localization of the diverse neurophysiological processes that are the substrate of psychological processes like memory, attention… Nevertheless, in order to do a clinic or scientific analysis of the relation between function and structure is necessary to develop quantification methods to probe the established hypothesis using statistical analysis. In this work we present a method that allow the quantification. This one was used in one Alzheimer disease patient and in one healthy person. This previous results invite to the application of the method in scientific studies and in clinical practice.

[The assessment of myocardial perfusion with thallium-201 in patients with a complete left His bundle-branch block]. / Evaluación de perfusión miocárdica con talio-201 en pacientes con bloqueo completo de rama izquierda del haz de His.

Thallium-201 myocardial scintigraphy was used to evaluate coronary perfusion in 20 patients with left bundle branch block suspected of having coronary artery disease. Contemporary coronary arteriography was performed in 9 of these patients. Sensitivity and specificity of the method was similar to that obtained in patients without LBBB. A false positive results indicated ischemia of the interventricular septal region in a patient with normal coronary arteries, a known limitation of the method.