ABSTRACT
OBJECTIVES: The pedunculopontine nucleus (PPN) is considered a promising new target for neurostimulation in Parkinson's disease (PD) patients with postural instability and gait disturbance that is refractory to other treatment modalities. However, the PPN is typically difficult to visualize with magnetic resonance imaging (MRI) at clinical field strengths, which greatly limits the PPN as a viable surgical target for deep brain stimulation (DBS). Thus, the aim of this study is to directly visualize the PPN based on 7.0T ultrahigh-field MRI. METHODS: Five PD patients were enrolled and scanned using the MP2RAGE sequence on a 7.0T ultrahigh-field MRI scanner. Then, the MP2RAGE sequences were imported into a commercially available navigation system. The coordinates of the directly localized PPN poles were recorded in the navigation system relative to the anterior commissure-posterior commissure plane. RESULTS: Our results indicated that the PPN presented intermediate signal intensity in the 7.0T ultrahigh-field MR images in comparison with the surrounding structure, such as the hypo-intensity of the periaqueductal gray and the hyperintensity of the neighboring white matter tracts, in PD patients. The mean coordinates for the rostral and caudal poles of PPN were 6.50 mm and 7.20 mm lateral, 1.58 mm and 2.21 mm posterior, and 8.89 mm and 13.83 mm relative to the posterior commissure. CONCLUSION: Our findings provide, for the first time, direct visualization of the PPN using the MP2RAGE sequence on a 7.0T ultrahigh-field MRI, which may improve the accuracy of stereotactic targeting of the PPN and improve the outcomes in patients undergoing DBS.
Subject(s)
Humans , Male , Female , Adult , Middle Aged , Parkinson Disease/diagnostic imaging , Magnetic Resonance Imaging/methods , Image Enhancement/instrumentation , Pedunculopontine Tegmental Nucleus/diagnostic imaging , Image Processing, Computer-Assisted/instrumentation , Image Processing, Computer-Assisted/methods , Magnetic Resonance Imaging/instrumentation , Image Enhancement/methods , Stereotaxic Techniques/instrumentation , Data AccuracyABSTRACT
PurposeWe developed a stereotactic device to guide the puncture for percutaneous nephrolithotripsy, which uses the distance from the target calyx to its perpendicular point on skin (SCD) to calculate the needle´s entry angle. This study seeks to validate the use of measurements obtained by ultrasound (US) and computerized tomography (CT) for needle´s entry angle calculation and to study factors that may interfere in this procedure.Materials and MethodsHeight, weight, abdominal circumference, CT of the urinary tract in dorsal decubitus (DD) and ventral decubitus (VD), and US of the kidneys in VD were obtained from thirty-five renal calculi patients. SCD obtained were compared and correlated with body-mass index (BMI).ResultsBMI was 28.66 ± 4.6 Kg/m2. SCD on CT in DD was 8.40 ± 2.06cm, in VD was 8.32 ± 1.95cm, in US was 6.74 ± 1.68cm. SCD measured by US and CT were statistically different (p < 0.001), whereas between CT in DD and VD were not. SCD of the lower calyx presented moderate correlation with BMI.ConclusionSCD obtained by CT in ventral and dorsal decubitus may be used for calculation of the needle´s entry angle. SCD obtained by US cannot be used. A rule for the correlation between BMI and the SCD could not be determined.
Subject(s)
Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged , Young Adult , Kidney Calices/anatomy & histology , Skin/anatomy & histology , Stereotaxic Techniques/instrumentation , Tomography, X-Ray Computed/instrumentation , Analysis of Variance , Body Mass Index , Equipment Design , Kidney Calices , Kidney Calices , Reference Values , Reproducibility of Results , Supine Position , Skin , Skin , Tomography, X-Ray Computed/methods , Waist CircumferenceABSTRACT
Foram utilizados 55 ratos machos da espécie Rattus novergicus, variedade Wistar, com o objetivo de propor um modelo experimental de trauma medular produzido por aparelho estereotáxico modificado, capaz de reproduzir clinicamente lesões medulares padronizadas. Após realização de laminectomia dorsal de T13, utilizou-se peso compressivo de 50,5g (25 animais - grupo I) ou 70,5g (30 animais - grupo II), durante cinco minutos, comprimindo a medula espinhal. Os animais foram assistidos durante oito dias, por meio de testes comportamentais para avaliar a sensibilidade dolorosa, a capacidade motora, o posicionamento tátil e proprioceptivo e a capacidade de manter-se em plano inclinado. No grupo I, observaram-se déficits neurológicos moderados e transitórios, que variaram entre os animais. No grupo II, foi possível obter um trauma padronizado, caracterizado por paraplegia bilateral e simétrica dos membros posteriores, perda de propriocepção e da sensibilidade dolorosa de todos os animais. A utilização do aparelho estereotáxico desenvolvido permite reproduzir clinicamente trauma medular padronizado em ratos, de maneira simples, econômica e satisfatória, o que poderá proporcionar avanços nas investigações terapêuticas, abrangendo doenças neurodegenerativas, como é o caso do trauma medular agudo.
Fifty-five male rats (Rattus novergicus), Wistar variety, were used with the purpose of suggesting an experimental model of spinal cord trauma performed by using a modified stereotaxic equipment capable to reproduce clinically (standardized) pattern spinal cord injury. After dorsal laminectomy of T13, a compression was performed with 50.5g (25 animals - group I) or 70.5g (30 animals - group II) during five minutes on spinal cord. The animals were assisted during eight days by behavioral tests to evaluate painful sensibility, motor capacity, proprioceptive and tactil placing, and stability on inclined plan. In the group I, moderate and transitory neurological deficits were observed, that varied among the animals. In the group II, a standardized trauma was obtained, characterized by bilateral and symmetrical paraplegia of hindlimbs, loss of proprioception, and painful sensibility in all the animals. The use of developed stereotaxic equipment allowed to reproduce pattern spinal cord injury in rats, by a simply, economic, and satisfactory way. This can provide progresses in the therapeutic investigations embracing neurodegenerative diseases, like spinal cord injury.
Subject(s)
Animals , Male , Rats , Spinal Cord Injuries , Stereotaxic Techniques/instrumentation , Neurodegenerative Diseases/pathology , Rats , Spinal CordABSTRACT
Este é um artigo ilustrativo sobre o desenvolvimentos dos aparelhos estereotáxicos desde os modeos aplicados a pesquisa anatômica em animais até os dias de hoje...
Subject(s)
Skull/surgery , Stereotaxic Techniques/history , Stereotaxic Techniques/instrumentation , Stereotaxic TechniquesABSTRACT
Os autores procuram realizar um trabalho de atualizaçäo nesta especialidade, que é a cirurgia estereotáctica e expor didaticamente alguns princípios que regem este procedimento, como a aplicaçäo de Geometria Plana para a localizaçäo do alvo, no que se constitui a teoria das coordenadas cartesianas e polares; bem como o princípio que rege o funcionamento dos equipamentos usados em Estereotaxia, como o sistema ortogonal ou translacional, "ArcðPhanton", "BurrðHole" e Arco Quadrante. A importância e limitaçäo da neuronavegaçäo, a radiocirurgia e a robótica, além da telepresença que é uma extensäo da realidade virtual
Subject(s)
Humans , Neurosurgery , Radiosurgery , Stereotaxic Techniques/instrumentationSubject(s)
Humans , Brain Mapping , Stereotaxic Techniques/instrumentation , Biopsy , Brain Mapping , Craniotomy/methods , Radiosurgery , Surgical InstrumentsABSTRACT
Se presenta una comunicación preliminar de la experiencia con el uso del Mammotome bajo estereotáxia para biopsia mamaria en 115 pacientes con 128 lesiones, realizadas en el Servicio de imagenología mamaria de la Clínica Alemana de Santiago entre agosto de 1999 y agosto del 2000
Subject(s)
Humans , Adult , Female , Aged , Middle Aged , Biopsy, Needle , Breast Diseases , Stereotaxic Techniques/instrumentation , Ambulatory Surgical Procedures/instrumentationSubject(s)
Humans , Craniotomy/instrumentation , Neurosurgical Procedures/instrumentation , Stereotaxic Techniques/instrumentation , Brain Mapping , Brain Mapping/instrumentation , Craniotomy/methods , Magnetic Resonance Spectroscopy/therapeutic use , Neurosurgical Procedures/methods , Tomography, Emission-Computed/methodsABSTRACT
En este reporte se analizan las lesiones no palpables de la mama, su frecuencia, forma de presentación radiológica y protocolo de estudio. Se describen los diferentes tipos de biopsias microinvasivas, con las respectivas indicaciones, ventajas y desventajas. Se utiliza la clasificación de BI-RADS, del Colegio Americano de Radiología y se proponen 2 algoritmos para nódulos y calcificaciones. Se incluye un protocolo de trabajo de las diferentes técnicas y se recomienda un seguimiento estricto de las pacientes biopsiadas. Diferentes publicaciones han demostrado que las biopsias microinvasivas con aguja de 14 y 11 G permiten un diagnóstico histológico definitivo con un rendimiento semejante a la biopsia quirúrgica
Subject(s)
Humans , Female , Breast Neoplasms , Mammography , Biopsy, Needle , Breast Neoplasms/pathology , Breast/pathology , Mammography/instrumentation , Stereotaxic Techniques/instrumentationABSTRACT
Apresentamos o caso de uma paciente com epilepsia refratária ao tratamento medicamentoso e submetida à monitorização em vídeo-eletrencefalografia por eletrodos de profundidade intracerebrais. A história, o exame clínico, a ressonância magnética (RM), a vídeo-eletroencefalografia e o estudo neuropsicológico não foram sufucientes para a determinação da área cerebral de origem das crises convulsivas. Eletrodos de profundidade intracerebrais colocados por estereotaxia guiada por RM possibilitaram o registro de forma muito clara da atividade epileptiforme, determinando com precisão a área cerebral epileptogênica a ser removida por cirurgia. Após lobectomia temporal anterior direita com amígdalo-hipocampectomia realizada há três meses, a paciente permanece sem crises convulsivas. Segundo informações obtidas durante o último Congresso da Liga Brasileira de Epilepsia, esta é a primeira cirurgia esterotáxica para colocação de eletrodos de profundidade intracerebrais em epilepsia no Brasil.
Subject(s)
Humans , Female , Adult , Electrodes, Implanted , Electroencephalography/instrumentation , Epilepsy/surgery , Stereotaxic Techniques/instrumentation , Tomography, X-Ray ComputedABSTRACT
A técnica da biópsia por fragmentos guiada pelo método estereotáxico é um tipo de biópsia utilizada nas lesões mamárias impalpáveis, relativamente livre de traumas, que visa a proporcionar diagnósticos confiáveis equivalentes aos da biópsia cirúrgica. As autoras avaliam os diagnósticos de 700 biópsias estereotáxicas em comparaçäo com os da peça cirúrgica nos casos malignos e de proliferaçäo epitelial atípica, com o objetivo de verificar a acurácia do referido método nesses casos
Subject(s)
Humans , Female , Adult , Middle Aged , Biopsy, Needle/methods , Breast Neoplasms/diagnosis , Breast/injuries , Stereotaxic Techniques/instrumentation , Breast/surgery , HistologySubject(s)
Humans , Female , Adult , Biopsy, Needle , Biopsy, Needle/statistics & numerical data , Biopsy, Needle/instrumentation , Biopsy, Needle/methods , Biopsy, Needle , Breast , Breast Neoplasms , Breast Diseases , Stereotaxic Techniques/instrumentation , Stereotaxic Techniques , Ultrasonography, Mammary , Biopsy , Biomarkers, Tumor , Predictive Value of TestsABSTRACT
Se realizan consideraciones con respecto a la utilización de agujas finas y gruesas para estudios citológicos o histologicos bajo guías ecográficas o estereotáxicas. Se analizan ventajas y desventajas de cada uno de los métodos recalcando las posibilidades de cada uno de ellos efectuados por equipo entrenado y permanentemente evaluado por correlaciones quirúrgicas o seguimientos
Subject(s)
Humans , Breast Neoplasms/diagnosis , Punctures , Biopsy, Needle , Biopsy, Needle/instrumentation , Punctures/instrumentation , Punctures/standards , Stereotaxic Techniques/instrumentation , Stereotaxic Techniques/standardsABSTRACT
The outcome of 110 stereotactic procedures performed on 100 patients with intracerebral masss lesions is reported. In 76 patients the procedure was purely diagnostic in 10 patients it was purely therapeutic and in 14 patients diagnosis and therapy was combined. No diagnosis could be established in six patients. Therapeutic procedures included aspiration of 16 cysts including 9 craniopharyngioma cysts. Brain abscesses including a brain stem abscess and two intracerebral haematomas were drained. One AVM was obliterated with cryoprobe. Overall, in 40% of the cases the management was changed as a direct result of the stereotactic biopsy and in 23% the management decision has helped a great deal. In 7% much better prognosis could be made and in 9% the prognosis was considered worse after histological diagnosis. Morbidity and mortality were 6% and 5% respectively. A definitive diagnosis in intracerebral mass lesions should always be made as there is no place for blind therapeutic management. There is no area of the brain that cannot be approached with safety and accuracy for the purpose of biopsy. The stereotactic technique enables refinement of the diagnosis and in a few cases refinement of treatment but it is not going to make inoperable lesions operable