RESUMEN
BACKGROUND: Gastric emptying scintigraphy has become the gold standard, by excellence, in gastric emptying studies. This method must be standardized for the correct interpretation of results. The ideal protocol must be performed with an egg sandwich or egg white poder, both labeled with 99mTc sulphur colloid. The aim of this study was to standardize and determine the protocol with99m Tc sulphur colloid incorporated in egg white and compare it with a hamburger labeled with 99mTc sulphur colloid as well. METHODS: We studied 30 patients who underwent gastric emptying scintigraphy with the two aforementioned meals. RESULTS: Emptying percentages and retention with both meals were similar within an hour and two; however, statistical significance arose until the third hour with a p value of 0.26 by using Student's t for independent samples. CONCLUSIONS: Gastric emptying studies in both protocols where similar with normal ranges. The egg white ingested must be consistent for reproducible results in gastric motility disease, like organoleptic and volume characteristics.
Introducción: la gammagrafía de vaciamiento gástrico (VG) es el estándar de oro para determinar el porcentaje de VG. La estandarización del método permite la obtención de resultados reproducibles. La dieta estandarizada se compone de un sándwich de albúmina de huevo en polvo reconstituida y marcada con 99mTc sulfuro coloidal (SC). El objetivo fue estandarizar y determinar el porcentaje de vaciamiento gástrico tras la ingesta del sándwich de albúmina de huevo y compararlo con el porcentaje de ingesta de una hamburguesa, ambos marcados con 99mTc sulfuro coloidal. Método: se incluyeron 30 pacientes a los que se les realizó estudio de gammagrafía de vaciamiento gástrico con las dos dietas propuestas. Resultados: los porcentajes de vaciamiento y retención con ambos tipos de alimentos fueron similares a la hora y a las dos horas; sin embargo, hubo diferencias significativas a las tres horas con un valor de p = 0.26, calculado mediante t de Student para muestras independientes. Conclusiones: los tiempos de vaciamiento gástrico con ambas dietas estuvieron dentro de rangos normales. La dieta estandarizada con albúmina de huevo reconstituida aporta ventajas en cuanto al estudio de las posibles alteraciones de la motilidad gástrica, como sus características organolépticas y de volumen.
Asunto(s)
Clara de Huevo , Vaciamiento Gástrico , Gastroparesia/diagnóstico por imagen , Radiofármacos , Azufre Coloidal Tecnecio Tc 99m , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Cintigrafía/métodos , Cintigrafía/normas , Carne Roja , Valores de ReferenciaRESUMEN
OBJETIVO: Criar um atlas de cintilografia de perfusão miocárdica e verificar sua aplicabilidade no auxílio computadorizado à detecção de defeitos perfusionais miocárdicos em pacientes portadores de cardiopatia isquêmica. MATERIAIS E MÉTODOS: O atlas foi criado com imagens de cintilografia de perfusão miocárdica, em condições de repouso e estresse, de 20 pacientes de ambos os gêneros com baixa probabilidade de doença arterial coronariana e julgadas normais por dois observadores experientes. Técnicas de registro de imagens e operações matemáticas sobre imagens foram utilizadas para obtenção de modelos de média e desvio-padrão da captação miocárdica percentual de cada gênero e condição fisiológica. RESULTADOS: Imagens de um paciente masculino e um feminino foram alinhadas com os atlas correspondentes, e os voxels apresentando valores de captação percentual dois desvios-padrão abaixo da média da respectiva região do atlas foram destacados nos cortes tomográficos e confirmados como defeitos de perfusão por dois observadores experientes. CONCLUSÃO: Demonstramos a criação de um atlas de cintilografia de perfusão miocárdica e obtivemos resultados promissores na sua utilização para auxílio à detecção de defeitos perfusionais. Entretanto, uma validação prospectiva com um número mais representativo de casos é necessária.
OBJECTIVE: To develop an atlas of myocardial perfusion scintigraphy and evaluating its applicability in computer-aided detection of myocardial perfusion defects in patients with ischemic heart disease. MATERIALS AND METHODS: The atlas was created with rest-stress myocardial perfusion scintigraphic images of 20 patients of both genders with low probability of coronary artery disease and considered as normal by two experienced observers. Techniques of image registration and mathematical operations on images were utilized for obtaining template images depicting mean myocardial uptake and standard deviation for each gender and physiological condition. RESULTS: Myocardial perfusion scintigraphy images of one male and one female patient were aligned with the corresponding atlas template image, and voxels with myocardial uptake rates two standard deviations below the mean voxel value of the respective region in the atlas template image were highlighted on the tomographic sections and confirmed as perfusion defects by both observers. CONCLUSION: The present study demonstrated the creation of an atlas of myocardial perfusion scintigraphy with promising results of this tool as an aid in the detection of myocardial perfusion defects. However, further prospective validation with a more representative sample is recommended.
Asunto(s)
Humanos , Corazón/fisiopatología , Diagnóstico por Computador , Procesamiento de Imagen Asistido por Computador , Miocardio , Medicina Nuclear , Cintigrafía , Obras de Referencia , Cintigrafía/normas , Tomografía Computarizada de Emisión de Fotón ÚnicoRESUMEN
Monitoring the quality of instrumentation used in nuclear medicine is mandatory to guarantee the clinical efficacy of medical practice. A national program for the quality control of nuclear medicine instruments was established in Cuba and was certified and approved by the regulatory authorities. The program, which establishes official regulations and audit services, sets up educational activities, distributes technical documentation, and maintains a national phantom bank, constitutes a valuable and useful tool to guarantee the quality of nuclear medicine instrumentation.
Asunto(s)
Programas de Gobierno/organización & administración , Medicina Nuclear/instrumentación , Medicina Nuclear/normas , Garantía de la Calidad de Atención de Salud/organización & administración , Cintigrafía/instrumentación , Cintigrafía/normas , CubaRESUMEN
El presente artículo realiza una descripción físico-matemática de los principales factores físicos que caracterizan la calidad de la imagen en Medicina Nuclear, así como una descripción conceptual de la degradación que sufre la información proveniente del objeto debido al sistema de imagen (cámara gamma). Seguidamente se realiza una presentación crítica de algunos métodos cualitativos y cuantitativos de valoración de la calidad de la imagen, colaterales al tradicional control de calidad del equipamiento, como son el análisis ROC, las Técnicas de Clustering y el Análisis Discriminante. Dentro de estas dos últimas, se analizan los principales factores que determinan la calidad de la imagen y cómo los mismos se traducen en cambios en los valores cuantitativos de las principales variables físicas que la caracterizan. Se realiza además una comparación entre los métodos, resaltando su utilidad para monitorear calidad de imagen, así como sus principales ventajas y desventajas.
Asunto(s)
Humanos , Análisis Discriminante , Análisis por Conglomerados , Cintigrafía/normas , Control de Calidad , Curva ROC , Medicina Nuclear , Tomografía Computarizada de Emisión de Fotón Único , Cámaras gamma/normas , Diagnóstico por Imagen/normas , Física , Matemática , Sensibilidad de ContrasteAsunto(s)
Humanos , Femenino , Biopsia del Ganglio Linfático Centinela/normas , Cintigrafía/normas , Metástasis Linfática , Metástasis Linfática/patología , Neoplasias de la Mama/complicaciones , Ganglios Linfáticos , Ganglios Linfáticos/patología , Axila , Carcinoma Ductal de Mama/complicaciones , Estadificación de Neoplasias/métodos , Invasividad Neoplásica , Invasividad Neoplásica/patología , Radiofármacos , Reacciones Falso NegativasRESUMEN
BACKGROUND: The usual treatment of pyloroduodenal peptic stenosis has been mainly surgical, through pyloroplasty or gastric resection, with or without vagotomy. Since the first description of treatment for this peptic complication by endoscopic balloon dilation perfomed by Benjamin in 1982 [2], this procedure has become a therapeutic option in association with the medical treatment of peptic disease. The aim of this study is to evaluate the results involving clinical, endoscopic, and gastric emptying scintigraphy parameters. METHODS: Between August 1998 and February 2000, 20 patients with pyloroduodenal stenosis refractory to conservative treatment were treated at the Gastrointestinal Endoscopy Unit of the University of São Paulo Medical School. All patients who presented clinical manifestations of pyloroduodenal stenosis underwent upper gastrointestinal endoscopy to confirm peptic stenosis. Biopsy of the narrowing for the confirmation of a benign disease and gastric biopsy for Helicobacter pylori detection were performed. The treatment consisted of dilation of the stenosis with type TTS (Through The Scope) hydrostatic balloon under endoscopic control, treatment of Helicobacter pylori infection, and gastric acid suppression with oral administration of proton pump inhibitor. All patients, except one who was excluded from this study, were submitted to a clinical endoscopic assessment and gastric emptying evaluation by ingestion of (99m)Tc before and after the treatment. Endoscopic evaluation considered the diameter of the stenotic area before and after treatment. A scintigraphic study compared the time of gastric emptying before and after balloon dilation. RESULTS: Nineteen patients completed treatment by hydrostatic balloon dilation. Clinical symptoms such as bloating (p < 0.0001), epigastric pain (p = 0.0159), gastric stasis (p < 0.0001), and weight gain (p = 0.036) showed significant improvement. The diameter of the stenotic area increased significantly (p < 0.01) after the dilation treatment as well as a better gastric emptying of (99m)Tc (p < 0.0001). CONCLUSION: The dilation of the peptic pyloroduodenal stenosis using a hydrostatic balloon is a safe and effective procedure. The evaluation with gastric scintigraphy by ingestion of (99m)Tc is an effective method of assessment for the improvement of gastric function, because its results corresponded to the clinical improvement after endoscopic treatment.
Asunto(s)
Cateterismo , Obstrucción Duodenal/diagnóstico por imagen , Obstrucción Duodenal/terapia , Estenosis Pilórica/diagnóstico por imagen , Estenosis Pilórica/terapia , Cateterismo/métodos , Constricción Patológica , Obstrucción Duodenal/complicaciones , Obstrucción Duodenal/fisiopatología , Endoscopía Gastrointestinal , Femenino , Vaciamiento Gástrico , Humanos , Masculino , Persona de Mediana Edad , Dolor/etiología , Dolor/fisiopatología , Estenosis Pilórica/complicaciones , Estenosis Pilórica/fisiopatología , Cintigrafía/normas , Gastropatías/etiología , Gastropatías/fisiopatología , Tecnecio , Resultado del Tratamiento , Aumento de PesoRESUMEN
A method for optimizing the administered activity in Static Nuclear Medicine Studies is validated by comparison with ROC curve. Discriminant analysis of image quality is the applied statistical technique. The constructed linear function owns as dependent parameters, the differentiated levels of image quality obtained by observer's criterion. The percentage of cases correctly classified is analyzed. The minimum value of the administered activity, which permit good image quality, can be proposed from the best results of the parameters selected by the function. The method was tested using planar images from a Jaszczak phantom, acquired under four activities (1088 MBq, 962 MBq, 740 MBq and 562 MBq). Two of the six measured Background-to-Signal ratios (S/B) were the parameters able to construct the function with high correlation respect to the expert criterion. The value of 740 MBq was the optimum after method application. The results were coincident with the application of ROC-analysis.
Asunto(s)
Humanos , Análisis Discriminante , Cintigrafía/normas , Control de Calidad , Curva ROC , Cámaras gamma , Fantasmas de Imagen , Medicina Nuclear/normas , Observación , Optimización de ProcesosRESUMEN
Five, 3-month-old mongrel dogs weighing between 4.5 to 5.5 kg were studied to evaluate and compare the efficiency of 99mTc-DTPA, 99mTc-MAG3, and 99mTc-DMSA in detecting gentamicin-induced renal tubular injury. After baseline renograms using all three methods, all dogs received daily intramuscular injections of gentamicin at a dose of 30-45 mg/kg. Additional studies were obtained after a cumulative dose of 450, 1,575, and 2,250 mg of gentamicin was reached. Glomerular filtration rate (GFR), effective renal plasma flow (ERPF), and percentage of total renal uptake measurements were calculated. Baseline and post-gentamicin injection blood urea nitrogen (BUN) and serum creatinine values were determined. A Duncan test revealed significant renal function impairment at 450 mgs of cumulated gentamicin with 99mTc-DMSA and at 1,575 mgs of cumulated gentamicin for 99mTc-DTPA and 99mTc-MAG3. There was no correlation between BUN and serum creatinine values when compared to gentamicin (p > 0.05). The images obtained with 99mTc-MAG3 were of better quality than those obtained with 99mTc-DTPA even under severe renal dysfunction. Percentage of 99mTc-DMSA uptake indicated renal damage, before than GFR and ERPF. BUN and serum creatinine measurements were poor indicators of gentamicin-induced renal failure.
Asunto(s)
Antibacterianos/farmacología , Gentamicinas/farmacología , Riñón/efectos de los fármacos , Riñón/diagnóstico por imagen , Cintigrafía/veterinaria , Radiofármacos , Animales , Antibacterianos/administración & dosificación , Perros , Relación Dosis-Respuesta a Droga , Femenino , Gentamicinas/administración & dosificación , Riñón/fisiología , Pruebas de Función Renal/veterinaria , Masculino , Valor Predictivo de las Pruebas , Cintigrafía/normas , Ácido Dimercaptosuccínico de Tecnecio Tc 99m , Tecnecio Tc 99m Mertiatida , Pentetato de Tecnecio Tc 99mRESUMEN
Métodos de diagnóstico por imágenes. Sistema respiratorio, diafragma y mediastino. Corazón y aorta. Abdomen en general y sistema digestivo. Sistema urinario. Sistema ginecológico y obstetricia. Esqueleto. Cabeza ósea. Sistema nervioso central. Radiología intervencionista
Asunto(s)
Humanos , Espectroscopía de Resonancia Magnética , Tomografía Computarizada por Rayos X/normas , Cintigrafía/normas , Ultrasonografía/normas , Angiografía/normas , Diagnóstico por Imagen/normas , Radiología/educación , Imagen por Resonancia Magnética/normas , Diagnóstico por Imagen/métodos , Radiología Intervencionista/educaciónRESUMEN
Métodos de diagnóstico por imágenes. Sistema respiratorio, diafragma y mediastino. Corazón y aorta. Abdomen en general y sistema digestivo. Sistema urinario. Sistema ginecológico y obstetricia. Esqueleto. Cabeza ósea. Sistema nervioso central. Radiología intervencionista