Presurgical planning for tumor resectioning

Abstract

Since the birth of functional magnetic resonance imaging (fMRI)-a noninvasive tool able to visualize brain function-now 15 years ago, several clinical applications have emerged. fMRI follows from the neurovascular coupling between neuronal electrical activity and cerebrovascular physiology that leads to three effects that can contribute to the fMRI signal: an increase in the blood flow velocity, in the blood volume and in the blood oxygenation level. The latter effect, gave the technique the name blood oxygenation level dependent (BOLD) fMRI. One of the major clinical uses is presurgical fMRI in patients with brain abnormalities. The goals of presurgical fMRI are threefold: 1) assessing the risk of neurological deficit that follows a surgical procedure, 2) selecting patients for invasive intraoperative mapping, and 3) guiding of the surgical procedure itself. These are reviewed here. Unfortunately, randomized trials or outcome studies that definitively show benefits to the final outcome of the patient when applying fMRI presurgically have not been performed. Therefore, fMRI has not yet reached the status of clinical acceptance. The final purpose of this article is to define a roadmap of future research and developments in order to tilt pre-surgical fMRI to the status of clinical validity and acceptance.

Young patients with focal seizures may have the primary motor area for the hand in the postcentral gyrus

“…The central sulcus was determined by the consensus of two investigators according to the anatomical MRI landmarks which have been previously validated (Berger et al, 1990;Yousry et al, 1997;Lehericy et al, 2000;Makela et al, 2001;Sunaert, 2006). The criteria defining the central sulcus included: the omega-shaped sulcus at 4−5 cm above the Sylvian fissure on the horizontal plane (Yousry et al, 1997).…”

“…The criteria defining the central sulcus included: the omega-shaped sulcus at 4−5 cm above the Sylvian fissure on the horizontal plane (Yousry et al, 1997). If there were potentially two sulci showing the omega shape, the sulcus just posterior to the precentral sulcus which has a junction with the superior frontal sulcus was defined as the central sulcus (Berger et al, 1990;Lehericy et al, 2000;Sunaert, 2006). The sulcus meeting the above criteria was determined on the 3D Tool Software package (Max-Planck-Institut, Cologne, Germany; von Stockhausen et al, 1997), where each patient's three-dimensional surface brain image was visualized simultaneously in the horizontal, coronal and sagittal planes and all views were automatically updated as the cursor was moved to any point in a given section (Germann et al, 2005).…”

“…In the present study of 65 children and young adults with medically-uncontrolled focal epilepsy, we systematically defined the central sulcus using well-established anatomical landmarks (Berger et al, 1990;Yousry et al, 1997;Lehericy et al, 2000;Makela et al, 2001;Sunaert, 2006) delineated on the three-dimensional brain surface MR image as previously described (von Stockhausen et al, 1997;Juhasz et al, 2000). The spatial relationship between the primary hand motor area determined by electrical stimulation and the anatomically-defined precentral gyrus was then determined on each individual's three-dimensional brain surface image.…”

Preoperative assessment using multimodal functional magnetic resonance imaging techniques in patients with brain gliomas

“…However, BOLD imaging has not yet reached the widespread clinical acceptance. This is due to numberous disadvantages and technical problems, such as lack of correct spatial localization, gross head movement, ghosting, limited success rate, and the lack of information about the underlying white matter structures and connections (35). Therefore, combining presurgical BOLD images with other techniques such as DTI and neuro-navigation will be a clinical trend in the near future.…”

“…Among these methods, MRS, BOLD, and DTI can add important functional aspects to conventional anatomical brain imaging, which has become available for the clinical evaluation of various brain lesions (35). In this study, the role of these functional imaging techniques in preoperative evaluation for brain glioma were analysed.…”