ABSTRACT
La detección de la patología relacionada con los doce pares craneales representa un importante desafío, tanto para los clínicos como para los radiólogos. Las técnicas de imagen son fundamentales para el manejo de muchos de los pacientes. Adicionalmente al conocimiento anatómico y de las entidades patológicas que potencialmente puedan afectarlos, la evaluación por imagen de los pares craneales requiere protocolos de exploración y técnicas de adquisición y procesado específicas. En este artículo se efectúa un repaso de los principales síntomas y síndromes relacionados con los nervios craneales que pueden precisar la realización de pruebas de imagen y la patología subyacente, así como una breve revisión de la anatomía y de las técnicas de imagen más adecuadas a la indicación
The detection of pathological conditions related to the twelve cranial pairs represents a significant challenge for both clinicians and radiologists; imaging techniques are fundamental for the management of many patients with these conditions. In addition to knowledge about the anatomy and pathological entities that can potentially affect the cranial pairs, the imaging evaluation of patients with possible cranial pair disorders requires specific examination protocols, acquisition techniques, and image processing. This article provides a review of the most common symptoms and syndromes related with the cranial pairs that might require imaging tests, together with a brief overview of the anatomy, the most common underlying processes, and the most appropriate imaging tests for different indications
Subject(s)
Humans , Cranial Nerves/diagnostic imaging , Cranial Nerve Diseases/diagnostic imaging , Diagnostic Imaging/methods , Symptom Assessment/methods , Central Nervous System Diseases/diagnostic imaging , Cranial Nerves/anatomy & histology , Magnetic Resonance Spectroscopy/methods , Cisterna Magna/diagnostic imagingABSTRACT
The detection of pathological conditions related to the twelve cranial pairs represents a significant challenge for both clinicians and radiologists; imaging techniques are fundamental for the management of many patients with these conditions. In addition to knowledge about the anatomy and pathological entities that can potentially affect the cranial pairs, the imaging evaluation of patients with possible cranial pair disorders requires specific examination protocols, acquisition techniques, and image processing. This article provides a review of the most common symptoms and syndromes related with the cranial pairs that might require imaging tests, together with a brief overview of the anatomy, the most common underlying processes, and the most appropriate imaging tests for different indications.
Subject(s)
Cranial Nerve Diseases/diagnostic imaging , Magnetic Resonance Imaging , Cranial Nerve Diseases/complications , Cranial Nerves/anatomy & histology , Cranial Nerves/physiology , Humans , Symptom AssessmentABSTRACT
Introducción. La investigación sobre la visión ocupa un lugar central en neurociencia. Nuevas técnicas de neuroimagen, como la resonancia magnética funcional (RMf), permiten aumentar el conocimiento sobre el funcionamiento del sistema visual rápidamente y de forma no invasiva. El presente estudio examina el efecto de pequeños cambios en la intensidad de un estímulo sobre la respuesta de la corteza visual. Objetivos. Analizar la reacción de la corteza visual ante diferentes intensidades de una fuente luminosa, y examinar las posibles diferencias en la respuesta BOLD entre controles y sujetos con fotofobia. Sujetos y métodos. Se realizo una RMf (3 T) a 20 controles y a 20 sujetos con fotofobia, durante la estimulación visual con diferentes intensidades de luz. Se cuantificó la respuesta BOLD, tanto el área como a la intensidad del cambio de señal, en el córtex occipital. Resultados. Se encontró una relación directa entre la intensidad de los estímulos y la respuesta de la corteza occipital, con cambios significativos en el área de activación y con tendencia similar (aunque no significativa) en la intensidad de la respuesta BOLD. Además, la respuesta cortical es más pronunciada en sujetos con fotofobia, sobre todo en intensidades bajas e intermedias. Conclusiones. La RMf se muestra como una técnica válida y robusta para el registro de respuestas consistentes y reproducibles entre distintos sujetos y grupos, tanto para el estudio del funcionamiento normal de la corteza occipital como en casos de respuesta anómala, lo que abre la posibilidad de utilizarla en estudios clínicos
Introduction. Visual system is a high interest topic in neuroscience research. The new neuroimaging techniques, such as functional magnetic resonance imaging (fMRI), allow us to quickly improve our knowledge on the visual system using non-invasive methods. This work examines the effect of small changes in the intensity of a visual stimulus over the BOLD response in the visual cortex. Aims. To perform a detailed analysis of the visual cortex reaction to different intensities of a light source and to verify the ties between the intensity of the visual stimulus and the cortical response. Subjects and methods. Using fMRI (3 T), we registered BOLD response (area and intensity of the signal change) in 20 photophobic patients and 20 controls while viewing different stimulus intensities from a light source. Results. We found a direct relation between stimulus intensity and occipital response. We show that cortical reactivity is higher in patients with photophobia than normal controls, specially for the lower and medium intensities. Conclusions. fMRI is a valid and robust technique to register consistent and reproducible responses in different groups of subjects. It is useful for the study of normal cortex functioning as well as for clinical use
Subject(s)
Humans , Magnetic Resonance Spectroscopy/methods , Vision Disorders/diagnosis , Visual Cortex/physiopathology , Photophobia/diagnosis , Reproducibility of ResultsABSTRACT
INTRODUCTION: Visual system is a high interest topic in neuroscience research. The new neuroimaging techniques, such as functional magnetic resonance imaging (fMRI), allow us to quickly improve our knowledge on the visual system using non-invasive methods. This work examines the effect of small changes in the intensity of a visual stimulus over the BOLD response in the visual cortex. AIMS: To perform a detailed analysis of the visual cortex reaction to different intensities of a light source and to verify the ties between the intensity of the visual stimulus and the cortical response. SUBJECTS AND METHODS: Using fMRI (3 T), we registered BOLD response (area and intensity of the signal change) in 20 photophobic patients and 20 controls while viewing different stimulus intensities from a light source. RESULTS: We found a direct relation between stimulus intensity and occipital response. We show that cortical reactivity is higher in patients with photophobia than normal controls, specially for the lower and medium intensities. CONCLUSIONS: fMRI is a valid and robust technique to register consistent and reproducible responses in different groups of subjects. It is useful for the study of normal cortex functioning as well as for clinical use.
Subject(s)
Visual Cortex , Adult , Electric Stimulation , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Visual Cortex/anatomy & histology , Visual Cortex/physiologyABSTRACT
Malignant fibrous histiocytoma (MFH) was only recognized as a primary bone tumor a few years ago. Although it is much rarer than malignant fibrous histiocytoma of soft tissues, it is not extremely uncommon. It predominantly affects long bones; however, it has been reported to occur in many different sites and at any age. MFH are aggressive tumors that can appear in association with other bone lesions, and they have a poor prognosis. We present our experience with 13 cases of MFH and review the literature to describe the main characteristics of this tumor.
Subject(s)
Bone Neoplasms/diagnostic imaging , Bone Neoplasms/pathology , Histiocytoma, Malignant Fibrous/diagnostic imaging , Histiocytoma, Malignant Fibrous/pathology , Magnetic Resonance Imaging , Adult , Aged , Female , Humans , Male , Middle Aged , RadiographyABSTRACT
El fibrohistiocitoma maligno óseo fue reconocido como tumor óseo primario hace pocos años y, aunque mucho más raro que su homónimo de partes blandas, no es excesivamente infrecuente. Aunque afecta preferentemente a huesos largos, ha sido descrito en múltiples localizaciones y a cualquier edad. Son tumores agresivos que pueden aparecer en relación con otras lesiones óseas y tienen mal pronóstico. Presentamos nuestra experiencia con 13 casos y realizamos una revisión bibliográfica que nos permita conocer mejor las principales características de este tumor
Malignant fibrous histiocytoma (MFH) was only recognized as a primary bone tumor a few years ago. Although it is much rarer than malignant fibrous histiocytoma of soft tissues, it is not extremely uncommon. It predominately affects long bones; however, it has been reported to occur in many different sites and at any age. MFH are aggressive tumors that can appear in association with other bone lesions, and they have a poor prognosis. We present our experience with 13 cases of MFH and review the literature to describe the main characteristics of this tumor
Subject(s)
Humans , Male , Female , Adult , Middle Aged , Aged , Bone Neoplasms/pathology , Bone Neoplasms , Histiocytoma, Benign Fibrous/pathology , Histiocytoma, Benign Fibrous , Magnetic Resonance ImagingABSTRACT
for a long time to the research field despite its unquestionable diagnostic value. The availavility of programs able to automatically obtain a spectrum, and the current possibility of estimating easily the relationship among its different peaks, have approached this diagnostic technology to the current clinical situation. With hydrogen MRI spectroscopy (MRS) it is possible to obtain additional information which make it possible to distinguish among different neurological alterations with similar morphological appearance, such as cerebral tumors and pseudotumoral types of inflammatory processes, or tumor recurrence and radionecrosis. On other occasions, it makes it possible to detect alterations which are invisible by imaging study, such as medial temporal sclerosis, or multiple sclerosis. It is also very useful in following-up many alterations, either in their natural history, as in Alzheimers disease, or in order to monitor treatments on cerebral tumors or infectious processes. However, MRS does not often show pathognomonic patterns, so it is always recommended to consider it not just in the clinical context, but as inseparable part of an MR study, either structural or functional (diffusion, perfusion), since it is this is how it provides more useful information from a clinical point of view.
Subject(s)
Magnetic Resonance Imaging/methods , Nervous System Diseases/diagnosis , Nervous System Diseases/pathology , Neurology/instrumentation , Humans , HydrogenABSTRACT
La espectroscopia es una técnica conocida desde los comienzos de la resonancia magnética, que a pesar de su indudable valor diagnóstico, debido a dificultades técnicas en su mayor parte, ha permanecido restringida durante largo tiempo al ámbito de la investigación. La incorporación de programas capaces de obtener un espectro de forma automática, así como la posibilidad actual de estimar fácilmente la relación entre los diferentes picos de éste, han acercado a la clínica diaria esta técnica diagnóstica, que está demostrando gran utilidad. Mediante la espectroscopia de hidrógeno es posible obtener información complementaria que permite distinguir entre diferentes alteraciones neurológicas con aspecto morfológico similar, como los tumores cerebrales y formas seudotumorales de procesos inflamatorios, o la recidiva tumoral y la radionecrosis. En otras ocasiones permite detectar alteraciones no visibles en un estudio de imagen, como en la esclerosis temporal mesial o la esclerosis múltiple. También es de gran valor en el seguimiento de muchas alteraciones, tanto en su historia natural, como en la enfermedad de Alzheimer, como para monitorizar tratamientos en tumores cerebrales o procesos infecciosos. La espectroscopia de hidrógeno, sin embargo, no presenta frecuentemente patrones patognomónicos, por lo que es siempre recomendable valorarla no sólo en el contexto clínico sino como parte inseparable de un estudio de imagen por resonancia magnética tanto estructural como en ocasiones funcional (difusión, perfusión), ya que es de esta manera como aporta una información más útil desde el punto de vista clínico (AU)
Subject(s)
Humans , Nervous System Diseases , Neurology , Hydrogen , Magnetic Resonance ImagingABSTRACT
A new case of afferent loop obstruction presenting as acute pancreatitis is described. It is an uncommon manifestation of the afferent loop syndrome: less than 20 cases found in the literature. The diagnosis of afferent loop obstruction should be suspected in any patient with acute pancreatitis and a previous Billroth II gastrectomy. Duodenopancreatic reflux seems to play an important role in the pathogenesis of acute pancreatitis in this situation. The "closed duodenal loop" experimental model of acute pancreatitis simulates quite closely this clinical situation. The physiopathological principles, diagnosis and treatment of this syndrome is reviewed.