Update on the diagnosis of encephalitis.

Autoimmune encephalitis are brain inflammatory processes that are classified into two main groups according to the underlying pathogenic mechanism: antibodies to intracellular antigens (paraneoplastic) and antibodies to extracellular or neuronal surface antigens. The clinical manifestations of autoimmune encephalitis are very varied and non-specific. Complementary tests included in its clinical diagnosis include determination of antibodies in serum or cerebrospinal fluid and magnetic resonance imaging (MRI). MRI may show characteristic patterns such as mesial temporal involvement, although in some cases it may be normal or non-specific. 18F-Fluorodeoxyglucose PET/CT (18F-FDG PET/CT) imaging may be helpful in cases of paraneoplastic autoimmune encephalitis to find the primary tumor. In autoimmune encephalitis mediated by antibodies to extracellular antigens, 18F-FDG PET/CT shows distinctive patterns that can aid clinical diagnosis. This continuing education aims to present in a clear and easy-to-understand way, the clinical features of autoimmune encephalitis, the difficulties in clinical diagnosis and the patterns seen on MRI and 18F-FDG PET/CT.

Regional disparity of HIV incidence and prevalence among men who have sex with men.

BACKGROUND: HIV incidence can be estimated with cross-sectional studies using clinical, serological, and molecular data. Worldwide, HIV incidence data in only men who have sex with men (MSM) are scarce and principally focus on those with healthcare or under treatment. However, better estimates can be obtained through studies with national representativeness. The objective was to estimate the prevalence, incidence, and factors associated with acquiring HIV in a national sample of MSM who attend meeting places, considering geographical regions. METHODS: A nationally representative survey of MSM attending meeting places was performed in Mexico. Participants answered a questionnaire, and a dried blood spot (DBS) was collected. Samples were classified as recent infections using an algorithm with HIV status, antiretroviral therapy, and the result of BED-EIA assay. Parameters were analysed considering regions and demographic and sexual behaviour characteristics. RESULTS: The national HIV prevalence was 17.4% with regional differences; the highest prevalence (20.7%) was found in Mexico City, and the lowest prevalence was found in the West region (11.5%). The incidence was 9.4 per 100 p/y, with regional values from 6.2 to 13.2 for the Northeast and the Centre regions, respectively. Age, age at sexual debut, low wealth index, and rewarded sex were associated with HIV prevalence. Centre region, use of private clinics as health services, and having sex exclusively with men were associated with recent HIV infections. CONCLUSIONS: The incidence and prevalence showed regional differences, suggesting a difference in the dynamics of HIV transmission; some regions have a greater case accumulation, and others have a greater rate of new infections. Understanding this dynamic will allow developing health programs focused on HIV prevention or treating people already living with HIV.

Cost-effectiveness analysis of a multidisciplinary health-care model for patients with type-2 diabetes implemented in the public sector in Mexico: A quasi-experimental, retrospective evaluation.

OBJECTIVE: In 2007, the Ministry of Health (MoH) in Mexico implemented a multidisciplinary health-care model (MHC) for patients with type-2 diabetes (T2D), which has proven more effective in controlling this condition than the conventional health-care model (CHC). RESEARCH DESIGN AND METHODS: We compared the cost-effectiveness of the MHC vs. the CHC for patients with T2D using a quasi-experimental, retrospective design. Epidemiologic and cost data were obtained from a randomly selected sample of health-care units, using medical records as well as patient- and facility-level data. We modelled the cost-effectiveness of the MHC at one, 10 and 20 years using a simulation model. RESULTS: The average cumulative costs per patient at 20 years were US$4,225 for the MHC and US$4,399 for the CHC. With a willingness to pay one gross domestic product (GDP) per capita per quality-adjusted life year (QALY) (US$8,910), the incremental net benefits per patient were US$1,450 and US$3,737 at 10 and 20 years, respectively. The MHC was cost-effective from the third year onward; however, increasing coverage to 500 patients per year rendered it cost-effective at year one. CONCLUSIONS: The MHC is cost-effective at 10 and 20 years. Cost-effectiveness can be achieved in the short term by increasing MHC coverage.

18F-FDG PET/CT y el síndrome de intolerancia inmunológica en el injerto renal no funcionante / 18F-FDG PET/CT and non-functioning renal graft intolerance syndrome

No disponible

Relevancia de la cuantificación en los estudios PET cerebrales con 18F-FDG / Relevance of quantification in brain PET studies with 18F-FDG

La inclusión de la PET 18F-FDG como biomarcador en los criterios de diagnóstico clínico de enfermedades neurodegenerativas y su indicación en el estudio precirugía en la epilepsia resistente a los fármacos permiten mejorar la especificidad del diagnóstico. La interpretación clásica de los estudios PET neurológicos se ha abordado de forma cualitativa, aunque en la última década hemos sido testigos del auge en los sistemas de evaluación cuantitativa. Este desarrollo técnico es de vital importancia en la práctica clínica, ya que mejora la especificidad y la reproducibilidad y reduce el efecto dependiente del observador derivado del análisis visual. Consideramos que es conveniente exponer la complejidad de las técnicas de procesamiento de imagen empleadas, lo que permitirá al especialista en Medicina Nuclear conocer sus ventajas e inconvenientes a la hora de incluirlas en la práctica clínica diaria

The inclusion of 18F-FDG PET as a biomarker in the diagnostic criteria of neurodegenerative diseases and its indication in the presurgical assessment for drug-resistant epilepsies allow to improve specificity of these diagnosis. The traditional interpretation of neurological PET studies has been performed qualitatively, although in the last decade, several quantitative evaluation methods have emerged. This technical development has become relevant in clinical practice, improving specificity, reproducibility and reducing the interrater reliability derived from visual analysis. In this article we update/review the main imaging processing techniques currently used. This may allow the Nuclear Medicine physician to know their advantages and disadvantages when including these procedures in daily clinical practice

Relevance of quantification in brain PET studies with 18F-FDG. / Relevancia de la cuantificación en los estudios PET cerebrales con 18F-FDG.

The inclusion of 18F-FDG PET as a biomarker in the diagnostic criteria of neurodegenerative diseases and its indication in the presurgical assessment for drug-resistant epilepsies allow to improve specificity of these diagnosis. The traditional interpretation of neurological PET studies has been performed qualitatively, although in the last decade, several quantitative evaluation methods have emerged. This technical development has become relevant in clinical practice, improving specificity, reproducibility and reducing the interrater reliability derived from visual analysis. In this article we update/review the main imaging processing techniques currently used. This may allow the Nuclear Medicine physician to know their advantages and disadvantages when including these procedures in daily clinical practice.

Medicina nuclear en la epilepsia: avances en el análisis de los estudios SPECT y PET / Nuclear medicine in epilepsy: new challenges in SPECT and PET analysis

No disponible

Captación de 131I en calcinosis tumoral en un paciente en hemodiálisis tratado de cáncer de tiroides / 131I uptake in tumoral calcinosis in a patient on hemodialysis treated for thyroid cancer

No disponible

PET amiloide en enfermedades neurodegenerativas que cursan con demencia / Amyloid PET in neurodegenerative diseases with dementia

La enfermedad de Alzheimer (EA) es una enfermedad neurodegenerativa que se caracteriza por un deterioro cognitivo progresivo y pérdida de memoria, siendo la causa más común de demencia. Los hallazgos anatomopatológicos de la EA son los depósitos de Aβ amiloide y proteína Tau, que producen disfunción sináptica y muerte neuronal. La PET amiloide es una técnica útil, disponible y no invasiva que nos proporciona información in vivo del depósito amiloide. En las últimas revisiones de los criterios diagnósticos de la EA se definen e incorporan los biomarcadores, que se clasifican en biomarcadores fisiopatológicos o de diagnóstico (aumento de la retención fibrilar amiloide observada por PET o disminución del péptido Aβ1-42 y elevación de las proteínas T-Tau y F-Tau en el LCR) y biomarcadores de neurodegeneración o topográficos (disminución del metabolismo temporoparietal en la PET-FDG y atrofia temporal medial en la RM). Recientemente se han creado unas recomendaciones específicas para la correcta utilización de los biomarcadores, donde se incluye la PET amiloide: deterioro cognitivo persistente/progresivo, deterioro cognitivo atípico, deterioro cognitivo de inicio precoz y diagnóstico diferencial entre EA y otras enfermedades neurodegenerativas que cursan con demencia. Nuevos estudios de investigación y ensayos clínicos están utilizando la PET amiloide en la evaluación y el desarrollo de nuevas terapias para la EA, así como para el estudio de otras enfermedades neurodegenerativas que cursan con demencia. En este trabajo revisamos algunos conceptos generales y profundizamos en el uso de esta nueva técnica y su relación con las enfermedades neurodegenerativas y el resto de las técnicas diagnósticas

Alzheimer's disease (AD) is a neurodegenerative condition characterized by progressive cognitive decline and memory loss, and is the most common form of dementia. Amyloid plaques with neurofibrillary tangles are a neuropathological hallmark of AD that produces synaptic dysfunction and culminates later in neuronal loss. Amyloid PET is a useful, available and non-invasive technique that provides in vivo information about the cortical amyloid burden. In the latest revised criteria for the diagnosis of AD biomarkers were defined and integrated: pathological and diagnostic biomarkers (increased retention on fibrillar amyloid PET or decreased Aβ1-42 and increased T-Tau or P-Tau in CSF) and neurodegeneration or topographical biomarkers (temporoparietal hypometabolism on 18F-FDG PET and temporal atrophy on MRI). Recently specific recommendations have been created as a consensus statement on the appropriate use of the imaging biomarkers, including amyloid PET: early-onset cognitive impairment/dementia, atypical forms of AD, mild cognitive impairment with early age of onset, and to differentiate between AD and other neurodegenerative diseases that occur with dementia. Amyloid PET is also contributing to the development of new therapies for AD, as well as in research studies for the study of other neurodegenerative diseases that occur with dementia where the deposition of Aβ amyloid is involved in its pathogenesis. In this paper, we review some general concepts and study the use of amyloid PET in depth and its relationship with neurodegenerative diseases and other diagnostic techniques

Amyloid PET in neurodegenerative diseases with dementia. / PET amiloide en enfermedades neurodegenerativas que cursan con demencia.

Alzheimer's disease (AD) is a neurodegenerative condition characterized by progressive cognitive decline and memory loss, and is the most common form of dementia. Amyloid plaques with neurofibrillary tangles are a neuropathological hallmark of AD that produces synaptic dysfunction and culminates later in neuronal loss. Amyloid PET is a useful, available and non-invasive technique that provides in vivo information about the cortical amyloid burden. In the latest revised criteria for the diagnosis of AD biomarkers were defined and integrated: pathological and diagnostic biomarkers (increased retention on fibrillar amyloid PET or decreased Aß1-42 and increased T-Tau or P-Tau in CSF) and neurodegeneration or topographical biomarkers (temporoparietal hypometabolism on 18F-FDG PET and temporal atrophy on MRI). Recently specific recommendations have been created as a consensus statement on the appropriate use of the imaging biomarkers, including amyloid PET: early-onset cognitive impairment/dementia, atypical forms of AD, mild cognitive impairment with early age of onset, and to differentiate between AD and other neurodegenerative diseases that occur with dementia. Amyloid PET is also contributing to the development of new therapies for AD, as well as in research studies for the study of other neurodegenerative diseases that occur with dementia where the deposition of Aß amyloid is involved in its pathogenesis. In this paper, we review some general concepts and study the use of amyloid PET in depth and its relationship with neurodegenerative diseases and other diagnostic techniques.

Concordancia entre la PET cerebral con 18F-FDG y los biomarcadores en líquido cefalorraquídeo en el diagnóstico de enfermedad de Alzheimer / Concordance between brain 18F-FDG PET and cerebrospinal fluid biomarkers in diagnosing Alzheimer's disease

Objetivos. El hipometabolismo cortical posterior por PET con 18F-FDG (PET-FDG) y la alteración de los niveles del péptido Aß1-42 y las proteínas Tau total (tTau) y Tau fosforilada (pTau) en líquido cefalorraquídeo (LCR) son biomarcadores establecidos para el diagnóstico de la enfermedad de Alzheimer (EA). Evaluamos la concordancia y la relación entre los resultados de la PET-FDG y los biomarcadores en LCR en pacientes sintomáticos con sospecha de EA. Material y métodos. Revisión retrospectiva de 120 pacientes con deterioro cognitivo admitidos en la Unidad de Neurología Cognitiva a los que se les ha realizado punción lumbar para la determinación de biomarcadores en LCR y una PET-FDG cerebral. Para el análisis de concordancia (coeficiente Kappa), el resultado de la PET-FDG y del conjunto de los biomarcadores-LCR se clasificó en cada paciente como normal, no-concluyente, o compatible-EA. Se efectuó además una regresión logística incluyendo las variables cuantitativas Aß1-42, tTau y pTau como predictores y la PET-FDG como variable dependiente. Resultados. El coeficiente Kappa ponderado entre PET-FDG y biomarcadores-LCR fue de 0,46 (IC 95%: 0,35-0,57). En el análisis por regresión logística, la Aß1-42 y la tTau fueron en conjunto capaces de discriminar un resultado PET metabólicamente sugestivo de EA de uno no sugestivo de EA, con una sensibilidad del 91% y una especificidad del 93% aplicando la recta de corte Aß1-42=44+1,3×tTau. Conclusiones. La concordancia entre la PET-FDG cerebral y los biomarcadores-LCR es moderada, lo cual indica su valor complementario en el diagnóstico de EA. Los niveles de Aß1-42 y tTau en LCR son buenos predictores del estatus metabólico característico de EA por PET-FDG cerebral (AU)

Objectives. Cortical posterior hypometabolism on PET imaging with 18F-FDG (FDG-PET), and altered levels of Aß1-42 peptide, total Tau (tTau) and phosphorylated Tau (pTau) proteins in cerebrospinal fluid (CSF) are established diagnostic biomarkers in Alzheimer's disease (AD). An evaluation has been made of the concordance and relationship between the results of FDG-PET and CSF biomarkers in symptomatic patients with suspected AD. Material and methods. A retrospective review was carried out on 120 patients with cognitive impairment referred to our Cognitive Neurology Unit, and who were evaluated by brain FDG-PET and a lumbar puncture for CSF biomarkers. In order to calculate their Kappa coefficient of concordance, the result of the FDG-PET and the set of the three CSF biomarkers in each patient was classified as normal, inconclusive, or AD-compatible. The relationship between the results of both methods was further assessed using logistic regression analysis, including the Aß1-42, tTau and pTau levels as quantitative predictors, and the FDG-PET result as the dependent variable. Results. The weighted Kappa coefficient between FDG-PET and CSF biomarkers was 0.46 (95% CI: 0.35-0.57). Logistic regression analysis showed that the Aß1-42 and tTau values together were capable of discriminating an FDG-PET result metabolically suggestive of AD from one non-suggestive of AD, with a 91% sensitivity and 93% specificity at the cut-off line Aß1-42=44+1.3×tTau. Conclusions. The level of concordance between FDG-PET and CSF biomarkers was moderate, indicating their complementary value in diagnosing AD. The Aß1-42 and tTau levels in CSF help to predict the patient FDG-PET cortical metabolic status (AU)

Seudotumor fibroelástico elastofibroma dorsi detectado por 18F-FDG PET/TC y por 131I SPECT/TC posterapia / Fibroelastic pseudotumor elastofibroma dorsi detected by 18F-FDG PET/CT scan and by postherapy radioiodine SPECT/CT

La captación de yodo radioactivo en el tejido tiroideo y en las metástasis del cáncer diferenciado de tiroides (CDT) y otros tejidos depende de la expresión del transportador de sodio-yodo (NIS). La permeabilidad vascular, derrames serosos, procesos inflamatorios y otros mecanismos también pueden desempeñar un papel en la acumulación de yodo radioactivo. Una mujer de 63 años fue sometida a terapia con yodo radiactivo y a un estudio de cuerpo completo después de la terapia, debido a la sospecha de metástasis pulmonar de carcinoma diferenciado de tiroides. La exploración no solo mostró captación en la metástasis de pulmón, sino también una captación difusa leve en la región posterior del tórax en ambos lados; en la SPECT/TC esta captación se localiza en un elastofibroma dorsi (ED) ya conocido, previamente diagnosticado mediante TC con contraste y visto también en una PET/TC con 18F-FDG. La captación de radioyodo en el ED, sobre todo si es típico, no plantea un problema de diagnóstico en el estudio de SPECT/TC, pero puede inducir a error en un estudio limitado a unas pocas imágenes planares, especialmente si la captación se produce de forma asimétrica, o el ED se encuentra en una localización insospechada (AU)

Radioiodine uptake in the thyroid tissue, metastasis of differentiated thyroid cancer (DTC), and in other tissues, depends on the expression of sodium-iodide symporter (NIS). Vascular permeability, effusions, inflammation, and other mechanisms may also play a role in the accumulation of radioactive iodine. A 63-year-old woman underwent radioiodine therapy, as well as a post-therapy whole-body scan, as she was suspected of having lung metastasis from thyroid carcinoma. The scan not only showed uptake at the lung metastasis but also a faint diffuse bilateral uptake in the posterior thorax. On SPECT/CT this uptake was located in a known Elastofibroma Dorsi (ED) previously diagnosed by contrast CT and viewed in a FDG PET/CT. The radioiodine uptake in ED, especially if typical, is not a diagnostic problem in SPECT/CT study, but can be misleading in a study limited to a few planar images, particularly if the uptake occurs asymmetrically, or ED is located in a unsuspected área (AU)

Concordance between brain 18F-FDG PET and cerebrospinal fluid biomarkers in diagnosing Alzheimer's disease. / Concordancia entre la PET cerebral con 18F-FDG y los biomarcadores en líquido cefalorraquídeo en el diagnóstico de enfermedad de Alzheimer.

OBJECTIVES: Cortical posterior hypometabolism on PET imaging with 18F-FDG (FDG-PET), and altered levels of Aß1-42 peptide, total Tau (tTau) and phosphorylated Tau (pTau) proteins in cerebrospinal fluid (CSF) are established diagnostic biomarkers in Alzheimer's disease (AD). An evaluation has been made of the concordance and relationship between the results of FDG-PET and CSF biomarkers in symptomatic patients with suspected AD. MATERIAL AND METHODS: A retrospective review was carried out on 120 patients with cognitive impairment referred to our Cognitive Neurology Unit, and who were evaluated by brain FDG-PET and a lumbar puncture for CSF biomarkers. In order to calculate their Kappa coefficient of concordance, the result of the FDG-PET and the set of the three CSF biomarkers in each patient was classified as normal, inconclusive, or AD-compatible. The relationship between the results of both methods was further assessed using logistic regression analysis, including the Aß1-42, tTau and pTau levels as quantitative predictors, and the FDG-PET result as the dependent variable. RESULTS: The weighted Kappa coefficient between FDG-PET and CSF biomarkers was 0.46 (95% CI: 0.35-0.57). Logistic regression analysis showed that the Aß1-42 and tTau values together were capable of discriminating an FDG-PET result metabolically suggestive of AD from one non-suggestive of AD, with a 91% sensitivity and 93% specificity at the cut-off line Aß1-42=44+1.3×tTau. CONCLUSIONS: The level of concordance between FDG-PET and CSF biomarkers was moderate, indicating their complementary value in diagnosing AD. The Aß1-42 and tTau levels in CSF help to predict the patient FDG-PET cortical metabolic status.

Fibroelastic pseudotumor elastofibroma dorsi detected by 18F-FDG PET/CT scan and by postherapy radioiodine SPECT/CT. / Seudotumor fibroelástico elastofibroma dorsi detectado por 18F-FDG PET/TC y por 131I SPECT/TC posterapia.

Radioiodine uptake in the thyroid tissue, metastasis of differentiated thyroid cancer (DTC), and in other tissues, depends on the expression of sodium-iodide symporter (NIS). Vascular permeability, effusions, inflammation, and other mechanisms may also play a role in the accumulation of radioactive iodine. A 63-year-old woman underwent radioiodine therapy, as well as a post-therapy whole-body scan, as she was suspected of having lung metastasis from thyroid carcinoma. The scan not only showed uptake at the lung metastasis but also a faint diffuse bilateral uptake in the posterior thorax. On SPECT/CT this uptake was located in a known Elastofibroma Dorsi (ED) previously diagnosed by contrast CT and viewed in a FDG PET/CT. The radioiodine uptake in ED, especially if typical, is not a diagnostic problem in SPECT/CT study, but can be misleading in a study limited to a few planar images, particularly if the uptake occurs asymmetrically, or ED is located in a unsuspected area.

Nuevos tiempos para la neuroimagen de Medicina Nuclear en España: ¿de dónde partimos? / A new era for Nuclear Medicine neuroimaging in Spain: Where do we start from in Spain?

Objetivo. conocer la situación de los estudios de neuroimagen de Medicina Nuclear que se realizaron en España en el año 2013 y primer trimestre del 2014, con el fin de definir las actividades del grupo de trabajo de Neuroimagen de la Sociedad Española de Medicina Nuclear e Imagen Molecular (SEMNIM). Material y métodos. Se diseñó un cuestionario de 14 preguntas dividido en 3 partes: características de los servicios (equipamiento y profesionales involucrados), tipo de exploraciones e indicaciones clínicas y métodos de evaluación. El cuestionario se remitió a los 166 servicios de Medicina Nuclear que figuraban en la secretaría de la Sociedad Española de Medicina Nuclear e Imagen Molecular. Resultados. Respondieron a la encuesta un total de 54 centros distribuidos entre todas las comunidades autónomas. La mayoría de los centros realizaron entre 300 y 800 exploraciones de neuroimagen al año, representando más de 25 exploraciones al mes. La media de equipos por servicio era de 3, teniendo la mitad de ellos equipos PET/TC y SPECT/TC. Las exploraciones realizadas con más frecuencia son la SPECT cerebral con 123I-FP-CIT, seguida de la SPECT cerebral de perfusión y de la PET con 18F-FDG, siendo las indicaciones clínicas más frecuentes los estudios de deterioro cognitivo seguidos por los de trastornos del movimiento. Para la evaluación de las pruebas la mayoría de los centros utilizaron únicamente la valoración visual, en la valoración cuantitativa la cuantificación por regiones de interés fue la más utilizada. Conclusiones. Los resultados reflejan cuál fue la actividad clínica del año 2013 y primer trimestre del 2014, siendo las indicaciones principales los estudios de deterioro cognitivo y trastorno del movimiento. La variabilidad en la evaluación de los estudios PET y la colaboración con los especialistas clínicos que demandan las exploraciones de neuroimagen de Medicina Nuclear son algunos de los retos que debemos afrontar en los próximos años (AU)

Objective. To determine the status of neuroimaging studies of Nuclear Medicine in Spain during 2013 and first quarter of 2014, in order to define the activities of the neuroimaging group of the Spanish Society of Nuclear Medicine and Molecular Imaging (SEMNIM). Material and methods. A questionnaire of 14 questions was designed, divided into 3 parts: characteristics of the departments (equipment and professionals involved); type of scans and clinical indications; and evaluation methods. The questionnaire was sent to 166 Nuclear Medicine departments. Results. A total of 54 departments distributed among all regions completed the questionnaire. Most departments performed between 300 and 800 neuroimaging examinations per year, representing more than 25 scans per month. The average pieces of equipment were three; half of the departments had a PET/CT scanner and SPECT/CT equipment. Scans performed more frequently were brain SPECT with 123I-FP-CIT, followed by brain perfusion SPECT and PET with 18F-FDG. The most frequent clinical indications were cognitive impairment followed by movement disorders. For evaluation of the images most sites used only visual assessment, and for the quantitative assessment the most used was quantification by region of interest. Conclusions. These results reflect the clinical activity of 2013 and first quarter of 2014. The main indications of the studies were cognitive impairment and movement disorders. Variability in the evaluation of the studies is among the challenges that will be faced in the coming years (AU)

A new era for Nuclear Medicine neuroimaging in Spain: Where do we start from in Spain? / Nuevos tiempos para la neuroimagen de Medicina Nuclear en España: ¿de dónde partimos?

OBJECTIVE: To determine the status of neuroimaging studies of Nuclear Medicine in Spain during 2013 and first quarter of 2014, in order to define the activities of the neuroimaging group of the Spanish Society of Nuclear Medicine and Molecular Imaging (SEMNIM). MATERIAL AND METHODS: A questionnaire of 14 questions was designed, divided into 3 parts: characteristics of the departments (equipment and professionals involved); type of scans and clinical indications; and evaluation methods. The questionnaire was sent to 166 Nuclear Medicine departments. RESULTS: A total of 54 departments distributed among all regions completed the questionnaire. Most departments performed between 300 and 800 neuroimaging examinations per year, representing more than 25 scans per month. The average pieces of equipment were three; half of the departments had a PET/CT scanner and SPECT/CT equipment. Scans performed more frequently were brain SPECT with 123I-FP-CIT, followed by brain perfusion SPECT and PET with 18F-FDG. The most frequent clinical indications were cognitive impairment followed by movement disorders. For evaluation of the images most sites used only visual assessment, and for the quantitative assessment the most used was quantification by region of interest. CONCLUSIONS: These results reflect the clinical activity of 2013 and first quarter of 2014. The main indications of the studies were cognitive impairment and movement disorders. Variability in the evaluation of the studies is among the challenges that will be faced in the coming years.