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1.
Rev. cuba. inform. méd ; 12(2): e394, tab, graf
Article in Spanish | LILACS, CUMED | ID: biblio-1144459

ABSTRACT

En radiología se utilizan varias técnicas imagenológicas para el diagnóstico de enfermedades y la asistencia en intervenciones quirúrgicas con el objetivo de determinar la ubicación y dimensión exacta de un tumor cerebral. Técnicas como la Tomografía por Emisión de Positrones y la Resonancia Magnética permiten determinar la naturaleza maligna o benigna de un tumor cerebral y estudiar las estructuras del cerebro con neuroimágenes de alta resolución. Investigadores a nivel internacional han utilizado diferentes técnicas para la fusión de la Tomografía por Emisión de Positrones y Resonancia Magnética al permitir la observación de las características fisiológicas en correlación con las estructuras anatómicas. La presente investigación tiene como objetivo elaborar un proceso para la fusión de neuroimágenes de Tomografía por Emisión de Positrones y Resonancia Magnética. Para ello se definieron 5 actividades en el proceso y los algoritmos a utilizar en cada una, lo cual propició identificar los más eficientes para aumentar la calidad en el proceso de fusión. Como resultado se obtuvo un proceso de fusión de neuroimágenes basado en un esquema híbrido Wavelet y Curvelet que garantiza obtener imágenes fusionadas de alta calidad(AU)


In radiology, various imaging techniques are used for the diagnosis of diseases and assistance in surgical interventions with the aim of determining the exact location and dimension of a brain tumor. Techniques such as Positron Emission Tomography and Magnetic Resonance can determine the malignant or benign nature of a brain tumor and study brain structures with high-resolution neuroimaging. International researchers have used different techniques for the fusion of Positron Emission Tomography and Magnetic Resonance, allowing the observation of physiological characteristics in correlation with anatomical structures. The present research aims to develop a process for the fusion of neuroimaging of Positron Emission Tomography and Magnetic Resonance Imaging. Five activities were defined in the process and the algorithms to be used in each one, which led identifying the most efficient ones to increase the quality in the fusion process. As a result, a neuroimaging fusion process was obtained based on a hybrid Wavelet and Curvelet scheme that guarantees high quality merged images(AU)


Subject(s)
Algorithms , Magnetic Resonance Imaging/methods , Positron-Emission Tomography/methods , Wavelet Analysis , Neuroimaging/methods , Cerebral Ventricle Neoplasms/diagnostic imaging
2.
Rev. argent. radiol ; 84(3): 85-92, ago. 2020. tab, graf, il.
Article in Spanish | LILACS | ID: biblio-1143920

ABSTRACT

Resumen Objetivo: El objetivo de este estudio es evaluar la relación de las cinéticas del antígeno prostático específico (PSA por su sigla en inglés) con la positividad de la tomografía por emisión de positrones/tomografía computada [PET/TC colina (PETC)]en pacientes con una recaída de cáncer de próstata (RCP). Materiales y métodos: Se realizó un trabajo retrospectivo de 48 pacientes con RCP post prostatectomía radical (PR) evaluados con PETC. Resultados: La PETC negativa tuvo una mediana de 16,3 meses y la PETC positiva de 5,5 meses (p = < 0,001) para el tiempo de doblaje de PSA (PSADT por su sigla en inglés); la PETC fue positiva en el 96% de los pacientes con un PSADT< 12 meses. La PETC negativa tuvo una mediana de 0,03 ng/ml/año y la PETC positiva de 4,1 ng/ml/año (p = < 0,001) para la velocidad del PSA (PSAVpor su sigla en inglés); la PETC fue positiva en el 92% de los pacientes con un PSAV > 0,75 ng/ml/año. Las áreas bajo la curva ROC para PSAV fue de 0,984 con un punto de corte de mayor discriminación de 0.785 ng/ml/año, mostrando razones de verosimilitud (LR por su sigla en inglés) LR + = 25 y LR- = 0,1. Para PSADT el ROC fue de 0,992 con un punto de corte de mayor discriminación de 11 meses, mostrando LR + = 11 y LR- = 0. Discusión: El PSA es un indicador inespecífico de PETC positiva. Un estudio inicial demostró que los pacientes con una RCP con una PETC positiva tenían un menor PSADT y una mayor PSAV que los pacientes con una PETC negativa. Conclusión: La positividad de la PETC se vio influenciada por las cinéticas del PSA, observándose que a menor PSADT y que a mayor PSAV mayor fue la probabilidad de la positividad de la PETC.


Abstract Purpose: The aim of this study is to evaluate the relationship between Prostate-Specific Antigen (PSA) kinetics and the detection of Prostate Cancer Relapse (PCR) with Positron-Emission Tomography (PETC). Material and methods: A retrospective study of 48 patients with a PCR after a radical prostatectomy evaluated with PETC was performed. Results: PSA Doubling Time (PSADT), with negative PETC, had a median of 16.3 months and the positive PETC a median of 5.5 months (p = < 0.001); 96% of patients with a PSADT <12 months had positive PETC. PSA Velocity (PSAV), negative PETC, had a median of 0.03 ng/ml/year and positive PETC a median of 4.1 ng/ml/year (p = < 0.001); 92% of patients who had a PSAV > 0.75 ng/ml/year had positive PETC. The ROC for PSAV was 0.984 with a cut-off value of 0.785 ng/ml/year, Showing Likelihood Ratios (LR) LR + = 25 and LR- = 0.1. The ROC for PSADT was 0.992 with a cut off value of 11 months, showing LR + = 11 and LR- = 0. Discussion: PSA is a nonspecific indicator of positive PETC. An initial study demon-strated that patients with a PCR and positive PETC had lower PSADT and higher PSAV than patients with a negative PETC. Conclusion: The rate of detection of PCR with PETC was influenced by the kinetics of PSA, and it was observed that the lower the PSADT and the higher the PSAV, the greater the probability of the positivity of the PETC.


Subject(s)
Humans , Male , Aged , Prostatic Neoplasms/diagnostic imaging , Prostate-Specific Antigen/pharmacokinetics , Neoplasm Recurrence, Local/diagnostic imaging , Prostatic Neoplasms/physiopathology , Tomography, X-Ray Computed/methods , Cross-Sectional Studies , Retrospective Studies , Prostate-Specific Antigen/blood , Positron-Emission Tomography/methods
3.
Rev. cuba. inform. méd ; 12(1)ene.-jun. 2020. tab, graf
Article in Spanish | LILACS, CUMED | ID: biblio-1126554

ABSTRACT

Técnicas como la Tomografía por Emisión de Positrones y la Tomografía Computarizada permiten determinar la naturaleza maligna o benigna de un tumor y estudiar las estructuras anatómicas del cuerpo con imágenes de alta resolución, respectivamente. Investigadores a nivel internacional han utilizado diferentes técnicas para la fusión de la Tomografía por Emisión de Positrones y la Tomografía Computarizada porque permite observar las funciones metabólicas en correlación con las estructuras anatómicas. La presente investigación se propone realizar un análisis y selección de algoritmos que propicien la fusión de neuroimágenes, basado en la precisión de los mismos. De esta forma contribuir al desarrollo de software para la fusión sin necesidad de adquirir los costosos equipos de adquisición de imágenes de alto rendimiento, los cuales son costosos. Para el estudio se aplicaron los métodos Análisis documental, Histórico lógico e Inductivo deductivo. Se analizaron e identificaron las mejores variantes de algoritmos y técnicas para la fusión según la literatura reportada. A partir del análisis de estas técnicas se identifica como mejor variante el esquema de fusión basado en Wavelet para la fusión de las imágenes. Para el corregistro se propone la interpolación Bicúbica. Como transformada discreta de Wavelet se evidencia el uso de la de Haar. Además, la investigación propició desarrollar el esquema de fusión basado en las técnicas anteriores. A partir del análisis realizado se constataron las aplicaciones y utilidad de las técnicas de fusión como sustitución a los altos costos de adquisición de escáneres multifunción PET/CT para Cuba(AU)


Techniques such as Positron Emission Tomography and Computed Tomography allow to determine the malignant or benign nature of a tumor and to study the anatomical structures of the body with high resolution images, respectively. International researchers have used different techniques for the fusion of Positron Emission Tomography and Computed Tomography because it allows observing metabolic functions in correlation with anatomical structures. The present investigation proposes to carry out an analysis and selection of algorithms that favor the fusion of neuroimaging, based on their precision. In this way, contribute to the development of fusion software without the need to purchase expensive high-performance imaging equipment, which is expensive. For the study the documentary analysis, logical historical and deductive inductive methods were applied. The best algorithm variants and techniques for fusion were analyzed and identified according to the reported literature. From the analysis of these techniques, the Wavelet-based fusion scheme for image fusion is identified as the best variant. Bicubic interpolation is proposed for co-registration. As a discrete Wavelet transform, the use of Haar's is evidenced. In addition, the research led to the development of the fusion scheme based on the previous techniques. From the analysis carried out, the applications and usefulness of fusion techniques were verified as a substitute for the high costs of acquiring PET / CT multifunction scanners for Cuba(AU)


Subject(s)
Image Processing, Computer-Assisted/methods , Software/standards , Tomography, X-Ray Computed/methods , Positron-Emission Tomography/methods , Wavelet Analysis , Cuba
4.
Rev. argent. cir ; 112(1): 51-54, mar. 2020. ilus
Article in English, Spanish | LILACS | ID: biblio-1125781

ABSTRACT

El schwannoma es un tumor neurogénico que se presenta más frecuentemente en el ángulo costovertebral del mediastino posterior, pero también en otras localizaciones dentro del tórax. Habitualmente suele ser una masa única, encapsulada, bien definida, con un tamaño aproximado 2 a 10 cm. Presentamos el caso de un paciente de 66 años, derivado a nuestro hospital por una masa de 13 cm localizada en el hemitórax inferior izquierdo. Se realizó una biopsia, y la resonancia magnética corroboró el diagnóstico de un tumor mediastínico gigante de la vaina neural. Se procedió a su resección completa sin complicaciones.


Schwannomas are neurogenic tumors, commonly located in the costovertebral angle of the posterior mediastinum, but with many intrathoracic locations. They usually present as a solitary, well-circumscribed and encapsulated mass with a size between 2 and 10 cm. We report a case of a 66-year-old male, referred to our hospital for a mass located at the left lower hemithorax with 13 cm in size. A percutaneous biopsy was performed, and magnetic resonance imaging confirmed the diagnosis of a resectable giant mediastinal nerve sheath tumor. Surgery was performed without complications.


Subject(s)
Humans , Male , Aged , Lung Neoplasms/pathology , Neurilemmoma/diagnostic imaging , Thorax/diagnostic imaging , Thoracotomy , Magnetic Resonance Spectroscopy/methods , Positron-Emission Tomography/methods , Electrocardiography
5.
Rev. argent. cir ; 112(1): 58-62, mar. 2020. tab
Article in English, Spanish | LILACS | ID: biblio-1125783

ABSTRACT

La ascitis quilosa posoperatoria (AQP) se debe a acumulación de líquido rico en triglicéridos en la cavidad peritoneal tras una lesión en la cisterna del quilo o en sus afluentes. Es infrecuente verla después de una hepatectomía. Se presenta el caso de un varón de 44 años con adenocarcinoma a 16 cm del margen anal T3N1, con metástasis que ocupaba casi la totalidad del lóbulo hepático derecho. Luego de quimioterapia se realizó hepatectomía derecha, observándose al cuarto día postoperatorio líquido del drenaje endotorácico de aspecto lechoso, con triglicéridos 223 mg/dL y 77 mg/dL de triglicéridos séricos. Se inició dieta sin grasas, hiperproteica, con ácidos grasos de cadena media y octreótide (100 microgramos subcutáneos cada 8 horas), con resolución del cuadro. En conclusión, la complicación quilosa puede tratarse exitosamente con un abordaje menos agresivo, sin suprimir la ingesta oral, utilizando octreótide subcutáneo, dieta exenta de grasas, suplementada con proteínas y ácidos grasos de cadena media.


Postoperative chylous ascites is an intraperitoneal collection of lymphatic fluid enriched with long-chain triglycerides that results from injury of the cisterna chyli or its main tributaries. This complication is rare after liver resections. Here, we report on the case of a 44 year-old man with a T3N1 rectal adenocarcinoma 16 cm above the anal margin, with metastatic compromise of almost the entire right liver lobe. Following chemotherapy, he underwent right liver resection. On postoperative day four, the thoracic drain evidenced milky fluid containing triglyceride 223 mg/dL with serum triglycerides 77 mg/dL. A fat-free diet was indicated with fat-free protein supplements, medium chain triglycerides and octreotide (100 μg subcutaneously every 8 hours), with complete resolution. In conclusion, postoperative chylous complications may be treated successfully by a less aggressive approach, with oral diet, subcutaneous octreotide, fat-free diet supplemented with proteins and medium chain fatty acids.


Subject(s)
Humans , Male , Adult , Chylous Ascites/complications , Hepatectomy/adverse effects , Pleural Effusion/diagnostic imaging , Postoperative Complications/diagnosis , Rectal Neoplasms/surgery , Radiography, Thoracic/methods , Positron-Emission Tomography/methods
6.
Rev. habanera cienc. méd ; 18(6): 873-885, nov.-dic. 2019. tab, graf
Article in Spanish | LILACS, CUMED | ID: biblio-1093913

ABSTRACT

Introducción: La incidencia de tumores primarios de origen desconocido en pacientes oncológicos es del 0,5 al 7 por ciento en el momento del diagnóstico con una supervivencia a los 3 y 5 años de 11 y 6 por ciento, respectivamente. Objetivo: valorar la utilidad de la técnica PET/CT-FDG (Tomografía por emisión de positrones con 18F-Fluordeoxiglucosa) en el diagnóstico de tumor primario de origen desconocido (TOD). Material y método: Se analizaron retrospectivamente los estudios PET/CT-FDG realizados en pacientes con el diagnóstico de TOD para la búsqueda de tumor primario, con estudios convencionales previos negativos, entre noviembre de 2017 y junio de 2018. El diagnóstico final se estableció mediante confirmación histológica y/o seguimiento clínico/radiológico por 8 meses. Resultados: 42 pacientes fueron estudiados, en 19 estudios PET/CT se evidenciaron focos de captación sugestivos de tumor primario, de los cuales 9 se confirmaron histológicamente como verdaderos positivos y sólo 1 correspondió a un falso positivo. De los 23 pacientes con PET/CT negativos para tumor primario, todos continuaron con diagnóstico de TOD a pesar de las múltiples pruebas diagnósticas. Conclusiones: La técnica PET/CT permitió identificar el 45,2 por ciento de los tumores primarios en la muestra de pacientes, lo que la convierte en una herramienta útil para el diagnóstico en pacientes con metástasis de origen desconocido. Se considera que el PET/CT-FDG debe ser incluido de manera precoz en los algoritmos diagnósticos en Cuba, permitiendo orientar la realización de pruebas complementarias subsiguientes(AU)


Introduction: The incidence of carcinoma of unknown primary origin in oncologic patients is from 0,5 percent to 7 percent at the time of diagnosis with an overall 3-year and 5-year survival of 11 percent and 6 percent, respectively. Objective: To assess the effectiveness of 18 F-FDG-PET/CT (18F-fluorodeoxyglucose posıtron emıssıon tomography) in the diagnosis of carcinoma of unknown primary origin (CUP). Material and Methods: F-FDG-PET/CT studies were conducted in patients with CUP in the search for primary tumor with negative previous conventional studies carried out from November, 2017 to June 2018. The final diagnosis was established by histological confirmation and/or clinical/radiological follow-up during 8 months. Results: A total of 44 patients were studied. There were evidences of suggestive CUP in 19 patients; 9 of them were histologically confirmed as true-positive and only 1 was a false-positive. Of the 23 patients with negative F-FDG-PET/CT studies for primary tumor, all of them continued with the diagnosis of CUP in spite of multiples diagnostic tests. Conclusions: The FDG-PET/CT technique allowed to identify 45,2 percent of the primary tumors in this study, which demonstrates that it is very useful tool for the diagnosis of metastases of unknown origin. It is considered that F-FDG-PET/CT studies should be included earlier in the diagnostic algorithms in Cuba, which will allow to indicate subsequent complementary tests(AU)


Subject(s)
Humans , Neoplasms, Unknown Primary/diagnosis , Positron-Emission Tomography/methods
7.
Gac. méd. Méx ; 155(4): 436-444, jul.-ago. 2019. tab, graf
Article in English, Spanish | LILACS | ID: biblio-1286530

ABSTRACT

Resumen La tomografía por emisión de positrones (PET) es una técnica de diagnóstico médico mediante la cual se obtienen imágenes funcionales a partir de registrar la biodistribución espacio-temporal de radiofármacos específicos dirigidos a blancos moleculares específicos, proveyendo información bioquímica a nivel molecular. A principios de la primera década de este siglo XXI, la Facultad de Medicina de la Universidad Nacional Autónoma de México implementó esta técnica de diagnóstico en México, convirtiéndose en pionera en aplicaciones PET en el país y Latinoamérica. Casi dos décadas después, la PET se ha convertido en una herramienta esencial en la clínica médica. En este artículo se describen los antecedentes, el estado actual, las perspectivas de la imagen molecular PET en México y el impacto que ha tenido en el manejo de pacientes con enfermedades oncológicas, neurológicas y cardiológicas.


Abstract Positron-emission tomography (PET) is a medical diagnostic technique by means of which functional images are obtained by recording the spatio-temporal biodistribution of specific radiopharmaceuticals targeted at specific molecular objectives, which provides biochemical information at the molecular level. Early in the first decade of this 21st century, the Faculty of Medicine of the National Autonomous University of Mexico acquired the technology to implement this diagnostic technique in Mexico, thus becoming a pioneer in PET applications in the country and in Latin America. Almost two decades after its implementation in Mexico, PET has become an essential tool in medical clinics. This article describes the background, current state and perspectives of PET molecular imaging in Mexico, and the impact it has had on the management of patients with oncological, neurological and heart diseases.


Subject(s)
Humans , Positron-Emission Tomography/methods , Radiopharmaceuticals/administration & dosage , Heart Diseases/diagnostic imaging , Mexico , Neoplasms/diagnostic imaging , Nervous System Diseases/diagnostic imaging
8.
Rev. argent. radiol ; 83(2): 77-86, jun. 2019. ilus
Article in Spanish | LILACS | ID: biblio-1020470

ABSTRACT

La sarcoidosis es una enfermedad granulomatosa no caseificante, multisistémica, de causa desconocida, que compromete al pulmón y a los ganglios linfáticos mediastinales entre el 90 y el 95% de los casos. También puede afectar otros órganos, como las glándulas salivales, piel, ojos, hígado, bazo, corazón, huesos y sistema nervioso central. La sarcoidosis tiene una baja prevalencia en Latinoamérica y es subdiagnosticada debido a la alta frecuencia de otros trastornos similares, como tuberculosis, lepra y micosis profundas. El diagnóstico presuntivo se establece con hallazgos imagenológicos característicos dentro de un contexto clínico apropiado y se confirma con la evidencia histológica de granulomas no caseificantes de células epiteliales, en ausencia de otras etiologías. Los hallazgos torácicos incluyen la afectación pulmonar, ganglionar y bronquial, los cuales son detectados a través de la radiografía (Rx) y tomografía computada (TC) de tórax, siendo esa última más sensible y específica. En este artículo, resaltamos la importancia de reconocer los patrones de presentación típicos y atípicos de la sarcoidosis en Rx y TC, así como la relevancia de las imágenes torácicas como elemento clave en el algoritmo diagnóstico de esa patología. También describimos la utilidad de la resonancia magnética (RM), como método adicional para el diagnóstico en casos de afectación cardíaca y el papel de la tomografía por emisión de positrones (PET-CT) en el seguimiento terapéutico.


Sarcoidosis is a non-caseating granulomatous, multisystemic disease of unknown cause that involves the lung and mediastinal lymph nodes in 90-95% of cases. It can also affect other organs such as the salivary glands, skin, eyes, liver, spleen, heart, bones and the central nervous system. Sarcoidosis has a low prevalence in Latin America and it is underdiagnosed due to the high frequency of other similar disorders such as tuberculosis, leprosy and deep mycosis. The presumptive diagnosis is established based on characteristic imaging findings within an appropriate clinical setting and is confirmed by histological evidence of non-caseating epithelioid cell granulomas, in the absence of other etiologies. Thoracic imaging findings include pulmonary, nodal and bronchial involvement, which are detected on chest radiography (CXR) and computed tomography (CT), this last one having a higher sensitivity and specificity. In this article, we highlight the importance of recognizing the typical and atypical presentation patterns of sarcoidosis on CXR and CT, as well as the relevance of thoracic images as key elements in the diagnostic algorithm of this pathology. We also describe the usefulness of magnetic resonance (MR) imaging as an additional method for diagnosis in cases of cardiac involvement and the role of positron emission tomography (PET-CT) in therapeutic follow-up.


Subject(s)
Humans , Sarcoidosis , Sarcoidosis/diagnostic imaging , Magnetic Resonance Spectroscopy/methods , Radiography/methods , Tomography, X-Ray Computed/methods , Sarcoidosis, Pulmonary/diagnostic imaging , Positron-Emission Tomography/methods , Sarcoidosis/diagnosis , Radiography, Thoracic
9.
Rev. bras. psiquiatr ; 41(2): 101-111, Mar.-Apr. 2019. tab, graf
Article in English | LILACS | ID: biblio-990827

ABSTRACT

Objective: To compare results of positron emission tomography (PET) with carbon-11-labeled Pittsburgh compound B (11C-PIB) obtained with cerebellar or global brain uptake for voxel intensity normalization, describe the cortical sites with highest tracer uptake in subjects with mild Alzheimer's disease (AD), and explore possible group differences in 11C-PIB binding to white matter. Methods: 11C-PIB PET scans were acquired from subjects with AD (n=17) and healthy elderly controls (n=19). Voxel-based analysis was performed with statistical parametric mapping (SPM). Results: Cerebellar normalization showed higher 11C-PIB uptake in the AD group relative to controls throughout the cerebral cortex, involving the lateral temporal, orbitofrontal, and superior parietal cortices. With global uptake normalization, greatest cortical binding was detected in the orbitofrontal cortex; decreased 11C-PIB uptake in white matter was found in the posterior hippocampal region, corpus callosum, pons, and internal capsule. Conclusion: The present case-control voxelwise 11C-PIB PET comparison highlighted the regional distribution of amyloid deposition in the cerebral cortex of mildly demented AD patients. Tracer uptake was highest in the orbitofrontal cortex. Decreased 11C-PIB uptake in white-matter regions in this patient population may be a marker of white-matter damage in AD.


Subject(s)
Humans , Male , Female , Aged , Aged, 80 and over , Carbon Radioisotopes , Cerebral Cortex/diagnostic imaging , Positron-Emission Tomography/methods , Alzheimer Disease/diagnostic imaging , White Matter/diagnostic imaging , Severity of Illness Index , Case-Control Studies
10.
ABC., imagem cardiovasc ; 32(1): 19-28, jan.-mar. 2019. ilus, graf
Article in Portuguese | SES-SP, LILACS, SES-SP, SESSP-IDPCPROD, SES-SP | ID: biblio-969863

ABSTRACT

A miocardiopatia hipertrófica é a cardiopatia hereditária mais comum e acomete cerca de 1:500 indivíduos na população geral. O diagnóstico, que nem sempre é simples pela variação fenotípica e pela concomitância de outras patologias, baseia-se, inicialmente, em critérios eletrocardiográficos e ecocardiográficos, e na ausência de outras doenças que cursem com hipertrofia ventricular. Tendo como base celular o desarranjo miofibrilar e a fibrose com alterações hemodinâmicas decorrentes, a miocardiopatia hipertrófica pode revelar isquemia miocárdica (não relacionada à aterosclerose) e morte súbita. Assim, a avaliação da repercussão funcional por meio da cintilografia de perfusão miocárdica pela técnica Single Photon Emission Computed Tomography (SPECT) tem ganhado espaço, uma vez que 25% dos pacientes com miocardiopatia hipertrófica demonstram defeitos de perfusão fixos ou isquêmicos. Neste âmbito, notam-se alterações perfusionais que não estão necessariamente associadas ao tipo de miocardiopatia hipertrófica, mas conseguem predizer morbimortalidade nestes indivíduos. Outra técnica cintilográfica mais recente é a tomografia por emissão de pósitrons (PET), que se destaca na avaliação da microcirculação, na reserva de fluxo coronário e no metabolismo miocárdico. Em pacientes com miocardiopatia hipertrófica, estudos têm demonstrado resultados desfavoráveis quanto menores o fluxo sanguíneo miocárdico e a reserva de fluxo coronário. A avaliação miocárdica metabólica pela PET parece útil no entendimento fisiopatológico desta doença e na avaliação prognóstica da ablação alcoólica, procedimento realizado em formas obstrutivas graves. Assim, esta revisão aborda o papel da cardiologia nuclear pelas técnicas SPECT e PET miocárdico na avaliação diagnóstica, prognóstica e terapêutica da miocardiopatia hipertrófica


Subject(s)
Humans , Male , Female , Radionuclide Imaging/methods , Cardiomyopathy, Hypertrophic, Familial/genetics , Cardiomyopathy, Hypertrophic, Familial/therapy , Positron-Emission Tomography/methods , Myocardial Perfusion Imaging/methods , Prognosis , Stroke Volume , Diagnostic Imaging/methods , Echocardiography/methods , Myocardial Ischemia/diagnosis , Death, Sudden , Diagnosis, Differential , Electrocardiography/methods , Heart Failure/diagnosis
11.
Clinics ; 74: e835, 2019. tab, graf
Article in English | LILACS | ID: biblio-1011902

ABSTRACT

The efficacy and toxicity of radionuclide therapy are believed to be directly related to the radiation doses received by target tissues; however, nuclear medicine therapy continues to be based primarily on the administration of empirical activities to patients and less frequently on the use of internal dosimetry for individual therapeutic planning. This review aimed to critically describe the techniques and clinical evidence of dosimetry as a tool for therapeutic planning and the main limitations to its implementation in clinical practice. The present article is a nonsystematic review of voxel-based dosimetry. Clinical evidence pointing to a correlation between the radiation dose and therapeutic response in various diseases, such as thyroid carcinoma, neuroendocrine tumors and prostate cancer, is reviewed. Its limitations include technical aspects related to image acquisition and processing and the lack of randomized clinical trials demonstrating the impact of dosimetry on patient therapy. A more widespread use of dosimetry in therapeutic planning involves the development of user-friendly dosimetric protocols and confirmation that dose estimation implies good efficacy and low treatment-related toxicity.


Subject(s)
Humans , Radioisotopes/administration & dosage , Radiometry/methods , Radiotherapy/methods , Radionuclide Imaging/methods , Time Factors , Tomography, Emission-Computed, Single-Photon/methods , Positron-Emission Tomography/methods
13.
Clinics ; 74: e1273, 2019. tab, graf
Article in English | LILACS | ID: biblio-1039567

ABSTRACT

OBJECTIVES: This study aimed to evaluate several methods to estimate glucose consumption in the male Wister rat brain as measured by PET. METHODS: Fourteen male Wistar normoglycemic rats were studied. The input function consisted of seventeen blood samples drawn manually from the femoral artery. Glucose uptake values were calculated using the input function resulting from the arterial blood samples and the tissue time-activity curve derived from the PET images. The estimated glucose consumption rate (Ki) based on the 2-tissue compartment model (2TCM) served as the standard for comparisons with the values calculated by the Patlak analysis and with the fractional uptake rate (FUR), standardized uptake value (SUV) and glucose corrected SUV (SUVglu). RESULTS: No significant difference between the standard Ki and the Patlak Ki was observed. The standard Ki was also found to have strong correlations and concordance with the Ki value estimated by the Patlak analysis. The FUR method presented an excellent correlation with the Ki value obtained by the 2TCM/Patlak analyses, in contrast to the SUV or SUVglu. CONCLUSIONS: From a methodological point of view, the present findings confirm the theoretical limitations of the cerebral SUV and SUVglu as a substitute for Ki in the estimation of glucose consumption in the brain. Our data suggest that the FUR is the surrogate to Ki.


Subject(s)
Animals , Male , Rats , Brain/metabolism , Brain/diagnostic imaging , Fluorodeoxyglucose F18/administration & dosage , Positron-Emission Tomography/methods , Glucose/metabolism , Rats, Wistar , Models, Animal
15.
Rev. bras. psiquiatr ; 40(2): 181-191, Apr.-June 2018. tab, graf
Article in English | LILACS | ID: biblio-959221

ABSTRACT

Objective: To conduct the first support vector machine (SVM)-based study comparing the diagnostic accuracy of T1-weighted magnetic resonance imaging (T1-MRI), F-fluorodeoxyglucose-positron emission tomography (FDG-PET) and regional cerebral blood flow single-photon emission computed tomography (rCBF-SPECT) in Alzheimer's disease (AD). Method: Brain T1-MRI, FDG-PET and rCBF-SPECT scans were acquired from a sample of mild AD patients (n=20) and healthy elderly controls (n=18). SVM-based diagnostic accuracy indices were calculated using whole-brain information and leave-one-out cross-validation. Results: The accuracy obtained using PET and SPECT data were similar. PET accuracy was 68∼71% and area under curve (AUC) 0.77∼0.81; SPECT accuracy was 68∼74% and AUC 0.75∼0.79, and both had better performance than analysis with T1-MRI data (accuracy of 58%, AUC 0.67). The addition of PET or SPECT to MRI produced higher accuracy indices (68∼74%; AUC: 0.74∼0.82) than T1-MRI alone, but these were not clearly superior to the isolated neurofunctional modalities. Conclusion: In line with previous evidence, FDG-PET and rCBF-SPECT more accurately identified patients with AD than T1-MRI, and the addition of either PET or SPECT to T1-MRI data yielded increased accuracy. The comparable SPECT and PET performances, directly demonstrated for the first time in the present study, support the view that rCBF-SPECT still has a role to play in AD diagnosis.


Subject(s)
Humans , Male , Female , Aged , Magnetic Resonance Imaging/methods , Tomography, Emission-Computed, Single-Photon/methods , Positron-Emission Tomography/methods , Alzheimer Disease/diagnostic imaging , Support Vector Machine , Brain Mapping , Case-Control Studies , Predictive Value of Tests , Sensitivity and Specificity , Fluorodeoxyglucose F18 , Educational Status
16.
Rev. Assoc. Med. Bras. (1992) ; 64(1): 71-84, Jan. 2018. graf
Article in English | LILACS | ID: biblio-896421

ABSTRACT

Summary The new technology of PET/MRI is a prototype of hybrid imaging, allowing for the combination of molecular data from PET scanning and morphofunctional information derived from MRI scanning. Recent advances regarding the technical aspects of this device, especially after the development of MRI-compatible silicon photomultipliers of PET, permitted an increase in the diagnostic performance of PET/MRI translated into dose reduction and higher imaging quality. Among several clinical applications, PET/MRI gains ground initially in oncology, where MRI per se plays an essential role in the assessment of primary tumors (which is limited in the case of PET/CT), including prostate, rectal and gynecological tumors. On the other hand, the evaluation of the lungs remains an enigma although new MRI sequences are being designed to overcome this. More clinical indications of PET/MRI are seen in the fields of neurology, cardiology and inflammatory processes, and the use of PET/MRI also opens perspectives for pediatric populations as it involves very low radiation exposure. Our review aimed to highlight the current indications of PET/MRI and discuss the challenges and perspectives of PET/MRI at HC-FMUSP.


Resumo A nova tecnologia PET/RM é o protótipo de diagnóstico por imagem híbrido e permite combinar dados moleculares obtidos da tomografia PET e informações morfofuncionais derivadas da ressonância magnética. Avanços recentes relativos a aspectos técnicos desse dispositivo, principalmente após o desenvolvimento de fotomultiplicadores de silício compatíveis com RM, permitiram uma melhora do desempenho diagnóstico da PET/RM traduzida em redução da dose e qualidade superior das imagens. Entre diversas aplicações clínicas, a PET/RM ganha espaço inicialmente no campo da oncologia, onde a RM tem papel essencial na avaliação de tumores primários (limitado no caso da PET/TC), incluindo tumores de próstata, reto e ginecológicos. Por outro lado, a avaliação dos pulmões ainda é um enigma, a despeito de novas sequências de RM que estão sendo criadas para tentar resolver essa questão. Outras indicações clínicas da PET/RM são encontradas no âmbito da neurologia, cardiologia e de processos inflamatórios, nos quais a técnica também abre perspectivas para pacientes pediátricos, já que envolve uma exposição baixíssima à radiação. Nossa revisão teve como objetivo destacar as indicações atuais da PET/RM e discutir os desafios e perspectivas da aplicação dessa técnica no Hospital das Clínicas da FMUSP.


Subject(s)
Humans , Male , Female , Magnetic Resonance Imaging/methods , Tomography, X-Ray Computed/methods , Positron-Emission Tomography/methods , Multimodal Imaging/methods , Positron Emission Tomography Computed Tomography/methods , Neoplasms/diagnostic imaging , Medical Oncology/instrumentation , Neoplasms/classification
17.
Braz. j. med. biol. res ; 51(1): e6724, 2018. tab, graf
Article in English | LILACS | ID: biblio-889005

ABSTRACT

Basal ganglia have complex functional connections with the cerebral cortex and are involved in motor control, executive functions of the forebrain, such as the planning of movement, and cognitive behaviors based on their connections. The aim of this study was to provide detailed functional correlation patterns between the basal ganglia and cerebral cortex by conducting an interregional correlation analysis of the 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) data based on precise structural information. Fifteen participants were scanned with 7-Tesla magnetic resonance imaging (MRI) and high resolution research tomography (HRRT)-PET fusion system using 18F-FDG. For detailed interregional correlation analysis, 24 subregions of the basal ganglia including pre-commissural dorsal caudate, post-commissural caudate, pre-commissural dorsal putamen, post-commissural putamen, internal globus pallidus, and external globus pallidus and 80 cerebral regions were selected as regions of interest on the MRI image and their glucose metabolism were calculated from the PET images. Pearson's product-moment correlation analysis was conducted for the interregional correlation analysis of the basal ganglia. Functional correlation patterns between the basal ganglia and cerebral cortex were not only consistent with the findings of previous studies, but also showed new functional correlation between the dorsal striatum (i.e., caudate nucleus and putamen) and insula. In this study, we established the detailed basal ganglia subregional functional correlation patterns using 18F-FDG PET/MRI fusion imaging. Our methods and results could potentially be an important resource for investigating basal ganglia dysfunction as well as for conducting functional studies in the context of movement and psychiatric disorders.


Subject(s)
Humans , Male , Female , Adult , Young Adult , Basal Ganglia/diagnostic imaging , Magnetic Resonance Imaging/methods , Cerebral Cortex/diagnostic imaging , Fluorodeoxyglucose F18 , Positron-Emission Tomography/methods , Glucose/metabolism , Reference Standards , Basal Ganglia/metabolism , Cerebral Cortex/metabolism , Reproducibility of Results , Radiopharmaceuticals
18.
Rev. cuba. hematol. inmunol. hemoter ; 33(2): 1-9, abr.-jun. 2017. ilus
Article in Spanish | LILACS, CUMED | ID: biblio-901077

ABSTRACT

La terapia regenerativa constituye hoy una prometedora alternativa de tratamiento para muchas enfermedades. En este trabajo se describe la utilidad de las tecnologías de imagen radioisotópica en la evaluación de la seguridad y eficacia de la terapia con células madre. Para ello se exponen algunos de los fenómenos que condujeron al desarrollo de la tecnología de imagen en medicina nuclear, así como las características generales de la tomografía computarizada por emisión de fotón único y por emisión de positrones. También se reseña la aplicación de las imágenes radioisotópicas en la evaluación de los cambios de biodistribución, flujo y perfusión en las zonas anatómicas afectadas por distintas enfermedades en las especialidades de angiología, ortopedia y cardiología, como resultado de los efectos regenerativos y proliferativos inducidos por las células madre. Se citan los radiofármacos y moléculas marcadas que se usan en la evaluación de la angiogénesis y la linfangiogénesis resultantes de la terapia celular y los marcadores radioisotópicos que permiten el rastreo de las células madre trasplantadas(AU)


Regenerative therapy is nowadays a promising alternative treatment for many diseases. The utility of radioisotope image technologies in assessing of the efficiency and security of stem cell therapies is described. We present some of the facts that led to development of the nuclear medicine image technology, as well as the general characteristics of single photon emission computed tomography and positron emission tomography. It was also included application of radioisotope images in the evaluation of biodistribution changes, flow and perfusion in anatomical affected zones by different diseases, in the fields of angiology, orthopedia and cardiology, as a result of the regenerative and proliferative effects induced by stem cells transplant. We mention the radiopharmaceuticals and labelled molecules used in the evaluation of angiogenesis and lymph angiogenesis resulting of cellular therapy and the radioisotopes markers that allow tracking of transplanted stem cells(AU)


Subject(s)
Humans , Stem Cells , Radionuclide Imaging/methods , Tomography, Emission-Computed, Single-Photon/methods , Positron-Emission Tomography/methods
19.
Acta cir. bras ; 32(3): 175-181, Mar. 2017. graf
Article in English | LILACS | ID: biblio-837692

ABSTRACT

Abstract Purpose: To examine a correlation of micro-PET images with photographic images of the digestive organs in abdominal sepsis model. Methods: Male Wistar rats weighing 265±18g were used. Abdominal sepsis was induced by ligature and cecal puncture. Micro-PET Images from abdominal cavity septic foci were obtained using 18-Fluoro-deoxyglucose, looking for a correlation with photographic images of abdominal cavity organs. Pearson's correlation test was used. Results: The mean standard uptake values (SUV) and lesion areas were 2.58±0.63SUVbwg/ml and 546.87±300.95mm2, respectively. There was a strong positive correlation between the two variables (r=0.863, p=0.137), which resulted in a coefficient of determination r2?0.75, meaning that 75% of SUV variation is explained by the lesion areas of digestive organs. Conclusion: Micro-PET allows high throughput assessment of lesion count and volume in pre-clinical rat model of CPL abdominal sepsis.


Subject(s)
Animals , Male , Sepsis/diagnostic imaging , Radiopharmaceuticals , Fluorodeoxyglucose F18 , Positron-Emission Tomography/methods , Intraabdominal Infections/diagnostic imaging , Time Factors , Reproducibility of Results , Rats, Wistar , Sepsis/pathology , Digestive System/pathology , Digestive System/diagnostic imaging , Disease Models, Animal , Photograph , Intraabdominal Infections/pathology
20.
Einstein (Säo Paulo) ; 15(1): 115-118, Jan.-Mar. 2017. graf
Article in English | LILACS | ID: biblio-840296

ABSTRACT

ABSTRACT In recent years, medical imaging with hybrid techniques has widely accepted and employed in clinical routine. PET/MRI offers significant advantages, including excellent contrast and resolution and reduced ionizing radiation, as compared to well-established PET/CT. Therefore, PET/MRI is a promising modality for oncologic imaging of some regions, such as brain, head and neck, liver and pelvis. This article set out to analyze clinical conditions that could benefit from PET/MRI imaging based on our caseload. The potential of PET/MRI to become the imaging modality of choice for assessment of neurologic and oncologic conditions associated with soft tissues is highlighted. Clinical aspects of PET/MRI and its application to clinical cases are illustrated with examples extracted from the authors’ preliminary experience.


RESUMO Nos últimos anos, imagens médicas com tecnologias híbridas tornaram-se amplamente aceitas e utilizadas na prática clínica. O PET/RM possui vantagens importantes, incluindo excelentes contrastes e resolução, e menor radiação ionizante, em comparação ao PET/TC. Por isto, é uma modalidade promissora para exames de imagem de pacientes oncológicos, para avaliar o cérebro, cabeça e pescoço, o fígado e a pelve. O objetivo deste artigo foi analisar as situações clínicas que se beneficiariam de exames de PET/RM a partir de uma casuística. Destacamos o potencial desta técnica se tornar o método de imagem de escolha para doenças neurológicas e oncológicas que envolvam partes moles. Os aspectos clínicos de PET/RM e sua aplicação aos casos clínicos são ilustrados com exemplos da experiência inicial dos autores.


Subject(s)
Humans , Male , Female , Middle Aged , Aged , Aged, 80 and over , Parkinson Disease/diagnostic imaging , Pelvic Neoplasms/diagnostic imaging , Magnetic Resonance Imaging/methods , Positron-Emission Tomography/methods , Multimodal Imaging/methods , Head and Neck Neoplasms/diagnostic imaging , Multiple Myeloma/diagnostic imaging , Brazil , Carcinoma/diagnostic imaging , Adenocarcinoma/diagnostic imaging , Reproducibility of Results , Neuroimaging/methods , Lymph Nodes/diagnostic imaging
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