RESUMEN
Magnetic Resonance Imaging (MRI) can be applied to study the effects of rehabilitation strategies for neuroscience research. An MRI-wrist robot is designed and used as a clinical tool to examine the process of the brain plasticity changes. In this robot, the patient actuation is accomplished with two standard air cylinders, located inside the MRI chamber with two degrees of freedom (flexion-extension and ulna-radial deviation) with pneumatic air transmission, consisting of simple mechanism converting rotary motion to linear independently. A pilot study of brain image aiming at revealing more effective therapeutic strategies carried out to confirm the technical aspects of the development and validation. In a healthy subject, both wrist movement of robot and subject demonstrated brain activity in the contralateral primary somatosensory cortex. Because the robot does not move during the patient's body, a stand was designed to allow the wrist robot and patient to fit comfortably within the MRI machine. While all the parts of the robot were carefully selected with strict MRI compatibility requirements, the robot was tested by presenting some pilot imaging data with null effects on the image quality, as well. Finally, the possible further development of the robot has been introduced for a rehabilitation assessment.
Asunto(s)
Procedimientos Quirúrgicos Robotizados , Rehabilitación de Accidente Cerebrovascular , Encéfalo/diagnóstico por imagen , Terapia por Ejercicio , Humanos , Imagen por Resonancia Magnética , Proyectos Piloto , Muñeca/diagnóstico por imagenRESUMEN
INTRODUCTION: Neuroendocrine tumors often metastasize to the liver and present with disabling hormonal symptoms. Hepatic artery chemoembolization (HACE) combined with somatostatin therapy, pre-embolization, peri-embolization and post-embolization, at doses to control symptoms, is an aggressive approach that can relieve hormonal symptoms with minimal morbidity and mortality. METHODS: Chemoembolization was performed using 30 mg of adriamycin, 50 mg of mitomycin, 12 ml of hexabrix, 10 ml of ethiodol, and 360-500-microm particles. Pancreastatin, a split product of chromogranin A, was measured pre-HACE and post-HACE in all patients. RESULTS: Forty-three chemoebolization procedures were performed in 34 symptomatic patients from December 1995 to August 1999. Seventeen patients had intestinal primaries (50%), seven had pancreatic primaries (20%), five had bronchial primaries (15%), and five had unknown primaries (15%). Systemic pancreastatin levels were improved or stable in 31 patients (78%). Symptoms were improved in these 31 patients (78%). Systemic serotonin levels were improved or stable in 24 patients (60%). Radiographic improvement or stability was seen in 18 patients (45%). Procedural related morbidity included pain, fevers, nausea, vomiting, and transient elevations of liver function studies in 75-100% of patients. There was one procedural related mortality (2%). Less than 20% improvement in pancreastatin levels from baseline was associated with death in five of five patients (100%). This was not observed with serotonin levels. CONCLUSION: Measurement of serum pancreastatin levels is an easy and useful method to predict success in patients who undergo HACE plus somatostatin therapy for metastatic neuroendocrine tumors to the liver. This therapeutic approach is effective in relieving symptoms in 78% of patients, with minimal major morbidity or mortality.
Asunto(s)
Quimioembolización Terapéutica , Arteria Hepática , Tumores Neuroendocrinos/sangre , Tumores Neuroendocrinos/terapia , Hormonas Pancreáticas/sangre , Somatostatina/análogos & derivados , Somatostatina/uso terapéutico , Adulto , Anciano , Anciano de 80 o más Años , Antineoplásicos/administración & dosificación , Antineoplásicos/farmacología , Biomarcadores de Tumor/sangre , Biomarcadores de Tumor/metabolismo , Quimioembolización Terapéutica/efectos adversos , Cromogranina A , Cromograninas/sangre , Cromograninas/metabolismo , Medios de Contraste/administración & dosificación , Doxorrubicina/administración & dosificación , Doxorrubicina/farmacología , Aceite Etiodizado/administración & dosificación , Femenino , Estudios de Seguimiento , Humanos , Ácido Yoxáglico/administración & dosificación , Neoplasias Hepáticas/sangre , Neoplasias Hepáticas/mortalidad , Neoplasias Hepáticas/secundario , Neoplasias Hepáticas/terapia , Masculino , Persona de Mediana Edad , Mitomicina/administración & dosificación , Mitomicina/farmacología , Tumores Neuroendocrinos/mortalidad , Tumores Neuroendocrinos/patología , Hormonas Pancreáticas/metabolismo , Serotonina/sangreAsunto(s)
Malformaciones Arteriovenosas/complicaciones , Malformaciones Arteriovenosas/diagnóstico por imagen , Absceso Encefálico/etiología , Infarto Encefálico/etiología , Embolia/diagnóstico por imagen , Embolia/etiología , Arteria Pulmonar/anomalías , Arteria Pulmonar/diagnóstico por imagen , Venas Pulmonares/anomalías , Venas Pulmonares/diagnóstico por imagen , Femenino , Humanos , Persona de Mediana Edad , RadiografíaRESUMEN
PURPOSE: To evaluate possible differences in neointimal development resulting from overdilation of rigid versus flexible vascular stents. MATERIALS AND METHODS: Twelve vascular sheaths were placed bilaterally through femoral arteries in six swine. After angiographic measurement, 12 stents (six flexible and six rigid) were balloon expanded to 8-mm diameters in 12 6-mm iliac arteries (approximately 30% overdilation). All stents were similar in surface area, gauge, and type of wire (tantalum). The primary difference was longitudinal flexibility (low hoop strength) versus rigidity (high hoop strength). Stents were studied with angiography and intravascular ultrasound 5 weeks after implantation. The animals were killed, and the stented segments were removed and examined histologically. RESULTS: Rigid stents maintained larger diameters than flexible stents: mean, 6.52 mm versus 5.82 mm (mean difference, 0.70; standard deviation [SD], 0.47; confidence interval [CI], +/- 0.49; P < .05). In addition, rigid stents developed a thicker, eccentric neointimal reaction relative to flexible stents: mean 1.08 mm versus 0.74 mm (mean difference, 0.338; SD, 0.315; CI, +/- 0.331; P < .05). CONCLUSION: Rigid stents maintain larger diameters over the long term relative to flexible stents when overdilated in normal swine arteries. However, a thicker neointima develops within the lumen of rigid stents at follow-up (greater late loss).
Asunto(s)
Arteria Ilíaca/patología , Stents/efectos adversos , Túnica Íntima/patología , Animales , Diseño de Equipo , Hiperplasia/etiología , PorcinosRESUMEN
The normal anatomy of the lateral ankle and subtalar ligaments seen at magnetic resonance (MR) imaging was studied in four cadaver ankles. Sixteen ankles of 11 healthy volunteers were imaged with four different MR imaging protocols to optimize technique. The anterior talofibular ligament was identified in 100% of the ankles of the volunteers in the axial plane, the calcaneofibular ligament in 81% of the ankles in the coronal plane, the cervical ligament in 69% of the ankles in the coronal plane and in 88% of the ankles in the sagittal plane, and the talocalcaneal ligament in 56% of the ankles in the coronal plane and in 62% of the ankles in the sagittal plane. It is concluded that thin-section (1-3-mm) MR imaging techniques, especially the one in which data are acquired with three-dimensional Fourier transform, are best for visualization of the ligaments. These techniques may play a role in the evaluation of patients with chronic ankle pain and instability.