RESUMEN
We utilized blood oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI) and MR perfusion imaging methods to study the influence of brain tumor neovascularity on the BOLD fMRI activation volume in the primary motor cortex (PMC). The results from 57 brain tumor cases demonstrated that, for grade IV gliomas only, decreases in the BOLD fMRI activation volumes within the ipsilateral PMC, when compared with that observed in the contralateral PMC, correlated with increases in the relative regional cerebral blood volume (rCBV) in the PMC. In addition, relative increases in the activation volumes, corresponding to decreases in the rCBV, exhibited a linear dependence on the distance between the grade IV glioma and PMC. These findings lend support to the hypothesis that decreases in the fMRI activation volumes adjacent to a GBM may, in part, be due to the increased contribution of aberrant tumor neovascularity, with the resultant de-coupling of blood flow from neuronal activity. The nature of the relationship between the resulting activation volumes and adjacent tumor characteristics is complex, but is found to be dependent on the tumor grade and type, as well as the distance of the tumor to the PMC.
Asunto(s)
Astrocitoma/irrigación sanguínea , Volumen Sanguíneo/fisiología , Neoplasias Encefálicas/fisiopatología , Glioblastoma/irrigación sanguínea , Aumento de la Imagen , Procesamiento de Imagen Asistido por Computador , Angiografía por Resonancia Magnética , Imagen por Resonancia Magnética , Corteza Motora/irrigación sanguínea , Neovascularización Patológica/fisiopatología , Oligodendroglioma/irrigación sanguínea , Oxígeno/sangre , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias Encefálicas/secundario , Femenino , Hemangiopericitoma/irrigación sanguínea , Humanos , Masculino , Neoplasias Meníngeas/irrigación sanguínea , Meningioma/irrigación sanguínea , Persona de Mediana Edad , Neuronas/fisiología , Flujo Sanguíneo Regional/fisiología , Estadística como AsuntoRESUMEN
The ability to effectively identify eloquent cortex in close proximity to brain tumours is a critical component of surgical planning prior to resection. The use of electrocortical stimulation testing (ECS) during awake neurosurgical procedures remains the gold standard for mapping functional areas, yet the preoperative use of non-invasive brain imaging techniques such as fMRI are gaining popularity as supplemental surgical planning tools. In addition, the intraoperative three-dimensional display of fMRI findings co-registered to structural imaging data maximizes the utility of the preoperative mapping for the surgeon. Advances in these techniques have the potential to limit the size and duration of craniotomies as well as the strain placed on the patient, but more research accurately demonstrating their efficacy is required. In this paper, we demonstrate the integration of preoperative fMRI within a neuronavigation system to aid in surgical planning, as well as the integration of these fMRI data with intraoperative ECS mapping results into a three-dimensional dataset for the purpose of cross-validation.
Asunto(s)
Neoplasias Encefálicas/cirugía , Corteza Cerebral/cirugía , Imagen por Resonancia Magnética , Neuronavegación , Cirugía Asistida por Computador , Adulto , Mapeo Encefálico , Neoplasias Encefálicas/fisiopatología , Corteza Cerebral/fisiopatología , Estimulación Eléctrica , Femenino , Humanos , Periodo Intraoperatorio , Masculino , Persona de Mediana Edad , Cuidados Preoperatorios , Resultado del TratamientoRESUMEN
We describe a case of translocation of temporo-parietal language function (Wernicke's area) to the contralateral hemisphere in a right-handed patient with a left temporo-parietal glioma. This translocation was identified by functional MR imaging (fMRI) and validated by direct cortical stimulation during gross-total resection. The current case exemplifies how preoperative fMRI can identify unexpected language organization as a result of tumor growth, affording surgery to patients who may otherwise be deemed inoperable.
Asunto(s)
Neoplasias Encefálicas/diagnóstico , Glioma/diagnóstico , Lóbulo Parietal/patología , Lóbulo Temporal/patología , Craneotomía , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Lóbulo Parietal/diagnóstico por imagen , Lóbulo Parietal/cirugía , Radiografía , Lóbulo Temporal/diagnóstico por imagen , Lóbulo Temporal/cirugíaRESUMEN
Functional magnetic resonance imaging (fMRI) has been adopted almost universally by disciplines that endeavor to understand how the brain works. As basic scientists tune the technique, clinicians are increasingly able to apply brain mapping with fMRI to their clinical practice. We present here a guide to using fMRI in a clinical setting. We discuss the basic considerations of functional brain mapping in patients with brain tumors including: patient screening and training, paradigm design, data analysis and interpretation of the fMRI scans.