Fusión de imágenes en neurocirugía / Image fusion in neurosurgery

Introducción: La fusión de imágenes permite integrar el máximo de información anatómico-funcional en una sola imagen. Su aplicación es en neuronavegación y planificación de radiocirugía. Nuestro objetivo es presentar la experiencia inicial de, nuestro departamento en el uso de esta técnica. Método: Se fusionó información imagenológica anatómica-funcional en formato DICOM3.0, en una estación de trabajo SUN (ULTRAESPARC) los voxeles se transformaron a una matriz isotropica. En 4 casos se utilizó para planeación estereotáxica fusionando Tomografía Computada (TC), con Resonancia Magnética (RM). En 3 casos de cirugía de epilepsia se fusionó imágenes de zonas ictales de Tomografía Computada de Emisión de Fotones Únicos (SPECT), con RM y TC para asistir en procedimientos decirugía de epilepsia. Resultados: La fusión de imágenes de RM y TC resultó útil en cirugía estereotáxica puescombina la mejor resolución de la RM con la menor distorsión de la TC. En cirugía de epilepsia la fusión de imágenes ayudó a identificar y resecar el área de interés. Conclusión: La fusión de imágenes aparenta ser una herramienta útil para el neurocirujano. Nosotros vemos aplicación de esta tecnología para biopsias estereotáxicas de lesiones infecciosas o tumorales que no son visibles en TC pero sí en RM y también en eldespliegue de información imagenológica de aspectos anatómicos y metabólicos en cirugía de epilepsia y tumoral.

Punción biopsia de lesiones mamarias no palpables con aguja gruesa bajo control estereotáxico: nuestra experiencia / Nonpalpable breast lesions: stereotaxic large core needle biopsy

Se analiza una serie de 40 biopsias extereotáxicas de lesiones mamarias no palpables efectuadas con aguja gruesa. El método desplaza a la citopunción aspirativa, ya que permite un adecuado análisis histológico evitándose eventuales biopsias quirúrgicas

Punción biopsia de lesiones mamarias no palpables con aguja gruesa bajo control estereotáxico: nuestra experiencia / Nonpalpable breast lesions: stereotaxic large core needle biopsy

Se analiza una serie de 40 biopsias extereotáxicas de lesiones mamarias no palpables efectuadas con aguja gruesa. El método desplaza a la citopunción aspirativa, ya que permite un adecuado análisis histológico evitándose eventuales biopsias quirúrgicas (AU)

Remoçäo por método estereotáxico de catéter ventricular perdido / Stereotaxic removal of a missing ventricular catheter

Relata-se a retirada de "catéter ventricular perdido" empregando técnica estereotáxica, em 2 doentes que apresentavam meningite resistente ao tratamento clínico. Conclui-se o método estereotáxico é uma alternativa simples e eficaz para a remoçäo de corpos estranhos profundamente situados no sistema nervoso central

Correlation of criteria used for localizing epileptic foci in patients considered for surgical therapy of epilepsy.

Criteria for anterior temporal lobectomy, performed on seven patients with partial complex seizures, were derived from a battery of fourteen presurgical tests. Seven tests were routine studies aimed at identifying a focus of epileptic excitability, while seven were designed to reveal areas of focal functional deficit. Conflicting information was frequently obtained from the tests of epileptic excitability, suggesting that it is probably inaccurate to view patients with partial complex seizures as having a single epileptogenic focus. Presurgical evaluation must therefore be aimed at identifying the focus most responsible for the patient's habitual seizures. Tests of focal functional deficit provided useful nonconflicting confirmatory information in each of the seven patients studied. The most reliable information was obtained from depth electrode implantation, and this procedure should be considered essential except when all evidence of surface-recorded epileptic excitability, including ictal onset, and evidence of focal functional deficit agree.

Computed tomography/guided stereotactic surgery: conception and development of a new stereotactic methodology.

Computed tomography (CT) has become the first modality to provide the patient's self-brain map for stereotactic neurosurgery. This paper describes our development of a nearly artifact-free stereotactic frame designed for CT imaging. The surgical procedure is performed within the CT scanner itself. The scanner's computer, via a new software program, spatially integrates the new stereotactic frame with the CT images of the patient and with the scanner gantry to provide rapid coordinate determinations, calculate potential probe trajectories, obtain target accuracy within 1 mm, and observe for any procedural complications. Our initial clinical experience with this system is described.

Combined stereotactic and peripheral surgical approach for spasmodic torticollis.

Thalamotomy with or without pallidotomy and peripheral denervation, if necessary, was performed in 14 cases of spasmodic torticollis or other late dystonias. Of 4 bilateral procedures, 2 had a good result, in 1 there was little change and in another the patient remained with a pseudobulbar syndrome, the only complication in this group. 1 patient only required peripheral denervation with a good result. Of the 9 patients who underwent unilateral thalamotomy, with or without pallidotomy, the result was excellent in 6 and good in 2 others, but in 4 of these 8 patients peripheral denervation was also performed.

Application of stereotactic principles to the treatment of trigeminal neuralgia.

The application of neuroanatomical and neurophysiological principles to the functional surgery of the trigeminal nerve is discussed. Particular attention has been directed toward correlating the three-dimensional anatomical features of the trigeminal nerve and the surrounding structures to the two-dimensional radiograph of this same region. In this regard, 20 trigeminal nerves, including the surrounding neurovascular structures from 10 cadaver sphenoid blocks, were examined. Measurements of the third, fourth and sixth cranial nerves in relation to the profile of the clivus were made from lateral radiographs of the sphenoid blocks. The position of the internal carotid artery in relation to these structures was also noted. These neurovascular relationships are of clinical importance when using the percutaneous thermocoagulation technique for the treatment of trigeminal neuralgia.

Computer-assisted stereotactic brain operations by means including computerized axial tomography.

With a computerized program system for stereotactic brain operations it becomes possible for the first time to react even before running a possible risk, e.g., in case of punctures in the midbrain, the brain stem, or in the hypothalamus, by simulating the operative procedure even before starting the operation itself. This is effected by the ability to change the penetration angle of the electrode or by choosing a different point of trepanation. The inclusion of computerized axial tomography, especially through the presentation of the CT scan, made to measure with the help of the linear transformation, and of the input of the cranial and ventricular coordinates through a digitizer, together with the coordinates resulting from the X-ray picture, brings the definition of the target point to a still greater optimum. Thus the safety and the precision of the stereotactic operation have been improved even further.

Stereotactic amygdalotomy for convulsive and behavioral disorders. Long-term follow-up study.

58 patients, whose convulsions and behavioral disorders did not respond to nonsurgical therapy, were treated with stereotactic amygdalotomy between 1963 and 1973. A retrospective study was carried out by a psychiatric research team 1--11 years postoperatively. Using reliable objective methods of assessment they found that 50% operated primarily for seizures, 33% for uncontrolled conduct disorders and 50% with both conditions seemed improved after surgery.

Spinal cord stereotactic techniques re trigeminal nucleotomy and extralemniscal myelotomy.

The application of stereotactic techniques to the spinal cord as a logical sequel to percutaneous procedures have produced significant developments by enabling the functional exploration of different cord structures. Radiofrequency lesions were placed either at the spinal trigeminal nucleus, for facial pain of central origin such as postherpetic neuralgia or anesthesia dolorosa as well as for neoplastic pain of extensive craniofacial distribution, or at the central cord region to interrupt preferentially multisynaptic nonspecific pathways mainly for midline and/or bilateral pain but also for patients with respiratory inadequacy or for certain central pain states. Technical aspects are reported, and physiological correlates relevant to surgery are analyzed. Results, indications and limitations are discussed.

Technique for chronic electrode or cannula implantation in decorticate animals.

A surgical technique is described which enables chronic recording of electrophysiological activity and chemical or electrical stimulation in the decorticated animal. This procedure circumvents the problems of inadequate electrode/cannula patency and of the short-term debilitating consequences of cortical ablation. These features make it possible to analyze the relationships between neuroelectrophysiology, behavior and the central mechanisms underlying the restitution of function following brain damage. The procedure appears to be suitable for a wide range of mature laboratory animals and offers several advantages over the few techniques currently available.

Stereotactic exploration of brain tumours by ultrasound.

A report upon a new technique for investigation of brain tumour anatomy by means of stereotactically directed ultrasound is presented with some illustrative cases. Information obtained with this technique has been found useful when deciding the treatment program for the tumour.