Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Neuronavigation”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed2004

[Functional neuronavigation. Fusion of functional MRI data in a neuronavigation system].

Neuronavigation systems integrating functional magnetic resonance imaging data have been reported recently, but generally without many details about methodology. We propose an easy method to perform functional neuronavigation by integrating functional MRI data analyzed with the Statistical Parametric Mapping 99 reference software, in the Stealth Station which is the most common neuronavigation system. Users of this new and promising technique, which requires further validation, must be aware of its limitations. Functional MRI data seem to be the major source of imprecision. As a result we do not yet recommend the use of functional neuronavigation without the control of direct cortical stimulations.

Brain Mapping↗
PubMed2004

Impact of neuronavigation and image-guided extensive resection for adult patients with supratentorial malignant astrocytomas: a single-institution retrospective study.

Neuronavigation has become an effective therapeutic modality and is used routinely for intra-axial tumor removal. This retrospective study was conducted to evaluate the clinical impact of neuronavigation and image-guided extensive resection for adult patients with supratentorial malignant astrocytomas. Between 1990 and 2002, 76 adult patients with pathologically confirmed malignant astrocytomas underwent craniotomy and removal of the tumors at the Toyama Medical and Pharmaceutical University Hospital. Of these 76 patients, 42 were treated using neuronavigation with conventional microneurosurgery and the other 34 were treated with conventional microneurosurgery alone. Postoperative early MRI with contrast enhancement was done, and gross total resection was defined as the complete absence of residual tumor. Survival time was analyzed with the Kaplan-Meier method. Prognostic factors were obtained from the Cox proportional hazards model. In univariate analysis, age (< 65), grade 3, preoperative KPS (>/= 80), use of neuronavigation, and gross total resection were significantly associated with longer survival. However, when the data were submitted to multivariate analysis, grade 3, preoperative KPS (>/= 80), and gross total resection were independent prognostic factors. The median survival periods of patients receiving gross total resection (vs. partial resection) and neuronavigation (vs. no neuronavigation) were 16 (vs. 9) months and 16 (vs. 10) months, respectively. The percentage of a gross total resection was significantly higher in the neuronavigation group compared to that in the no-navigation group (64.3 % vs. 38.2 %, p < 0.05). Neurological deterioration occurred in 4 of 42 (9.5 %) and in 6 of 34 (17.6 %) patients after surgery with neuronavigation and surgery without neuronavigation, respectively, although this difference was not statistically significant. Our results showed that neuronavigation increases the radicality in the resection of malignant astrocytomas and is objectively useful for improving survival time.

Adolescent↗
PubMed2003

Evaluation of neuronavigation in lesional and non-lesional epilepsy surgery.

OBJECTIVE: For many patients, surgery for intractable epilepsy provides not only freedom or substantial relief from seizures, but also functional improvement and increased quality of life. Precise intraoperative localization of the underlying structural and functional processes is crucial in this regard. The aim of this study was to clinically evaluate whether neuronavigation leads to an improvement in the precision and safety of epilepsy surgery. In this paper, we also attempt to assess the navigation workstation as a platform for the integration of multimodal information (multimodal information guidance). PATIENTS: Out of a series of 223 epilepsy surgery procedures, 140 were performed with the aid of neuronavigation. Patient and surgical data were prospectively collected. METHODS: We used the neuronavigation device as a common platform to merge complementary information modalities. Correlation of anatomic and structural details with functional information contributed to the surgical script in non-lesional and localization-related epilepsy surgery. At least two different information modalities contributed to planning and surgical guidance in every patient. Immediately following the operative procedure, the surgeon answered a set of questions on the reasons for the application of neuronavigation, and the efficiency and safety of navigation. Detailed analysis of the location of the operative procedure, histopathological findings and outcome was performed. RESULTS: The main benefits of neuronavigation in epilepsy surgery were precision of targeting even in small and deep-seated targets, safe manipulation in critical brain areas, accurate placement of electrodes, and correlation of electro-clinical information modalities with underlying structures. Furthermore, navigation provided individual tailoring of craniotomy and corticotomy. It was less reliable for verification of resection boundaries in the case of underlying glioma. Neuronavigational localization and its combination with image fusion and functional investigations greatly improved discussion within the epilepsy surgery team. CONCLUSION: The neuronavigation concept proved its value in epilepsy surgery by linking anatomic, pathologic and functional data of the individual patient. Enhanced by the integration of multimodal information, neuronavigation significantly improved the available treatment options.

Adolescent↗
PubMed2000

A data fusion environment for multimodal and multi-informational neuronavigation.

OBJECTIVE: Part of the planning and performance of neurosurgery consists of determining target areas, areas to be avoided, landmark areas, and trajectories, all of which are components of the surgical script. Nowadays, neurosurgeons have access to multimodal medical imaging to support the definition of the surgical script. The purpose of this paper is to present a software environment developed by the authors that allows full multimodal and multi-informational planning as well as neuronavigation for epilepsy and tumor surgery. MATERIALS AND METHODS: We have developed a data fusion environment dedicated to neuronavigation around the Surgical Microscope Neuronavigator system (Carl Zeiss, Oberkochen, Germany). This environment includes registration, segmentation, 3D visualization, and interaction-applied tools. It provides the neuronavigation system with the multimodal information involved in the definition of the surgical script: lesional areas, sulci, ventricles segmented from magnetic resonance imaging (MRI), vessels segmented from magnetic resonance angiography (MRA), functional areas from magneto-encephalography (MEG), and functional magnetic resonance imaging (fMRI) for somatosensory, motor, or language activation. These data are considered to be relevant for the performance of the surgical procedure. The definition of each entity results from the same procedure: registration to the anatomical MRI data set (defined as the reference data set), segmentation, fused 3D display, selection of the relevant entities for the surgical step, encoding in 3D surface-based representation, and storage of the 3D surfaces in a file recognized by the neuronavigation software (STP 3.4, Leibinger; Freiburg, Germany). RESULTS: Multimodal neuronavigation is illustrated with two clinical cases for which multimodal information was introduced into the neuronavigation system. Lesional areas were used to define and follow the surgical path, sulci and vessels helped identify the anatomical environment of the surgical field, and, finally, MEG and fMRI functional information helped determine the position of functional high-risk areas. CONCLUSION: In this short evaluation, the ability to access preoperative multi-functional and anatomical data within the neuronavigation system was a valuable support for the surgical procedure.

Adult↗
PubMed2000

The benefit of neuronavigation for neurosurgery analyzed by its impact on glioblastoma surgery.

Neuronavigation, today a routine method in neurosurgery, has not yet been systematically assessed in direct comparison with conventional microsurgical techniques. The aim of the present study was the direct comparison of the impact of neuronavigation on glioblastoma surgery regarding time consumption, extent of tumor removal and survival. For each of 52 patients operated for primary glioblastoma with neuronavigation, a patient operated on without navigation was matched. Completeness of tumor resection, including volumetric analysis, was examined by early post-operative MRI. Operating and survival times were obtained for all patients. At a rate of 86.5%, surgeons' opinions about neuronavigation were positive. Operating times were identical in the two groups, while preparation times were 30.4 min longer with navigation. Radiological radicality was achieved in 31% of navigation cases vs. 19% in conventional operations. The absolute and relative residual tumor volumes were significantly lower with neuronavigation. Radical tumor resection was associated with a highly significant prolongation in survival (median 18.3 vs. 10.3 months, p < 0.0001). Survival was longer in patients operated on using neuronavigation (median 13.4 vs. 11.1 months). Neuronavigation increases radicality in glioblastoma resection without prolonging operating time. Regarding the problem of brain shift, neuronavigation should be optimized by intraoperative real-time imaging.

Adult↗
PubMed2005

Advanced neuronavigation in skull base tumors and vascular lesions.

OBJECTIVE: The purpose of this study was to describe the usefulness of recent advances of neuronavigational technology in the management of skull base tumors and of vascular lesions, treated via a skull base approach. METHODS: In 16 patients (skull base meningioma n = 9, petrous apex epidermoid n = l, craniopharyngeoma n = 1, giant internal carotid artery aneurysm n = 1, basilar/vertebral artery aneurysm n = 2, brain stem cavernoma n = 2), "advanced" neuronavigation was used. In contrast to "conventional" neuronavigation, the information for the neurosurgeon was enhanced by the intraoperative screen display of 3-dimensional reconstructions of the lesion, vessels, nerves and fiber tracts at risk. The 3-dimensional reconstructions were obtained by preoperative manual or automated segmentation processes. In addition, different imaging modalities (computed tomography [CT] with magnetic resonance imaging [MRI], CT with CT angiography, T (l)- with diffusion-weighted MRI) were fused and shown on the screen. RESULTS: In the cases of tumors, "advanced" neuronavigation facilitated the approach (n = 4), contributed to tailor the approach (n = 2) and helped to identify hidden neurovascular structures (n = 9). In the cases of aneurysms, "advanced" neuronavigation allowed us to reduce the skull base approach to the needs of safe aneurysm clipping (n = 3). In both cases of brain stem cavernoma, "advanced" neuronavigation was deemed useful for definition of the best surgical approach in relation to the pyramidal tract and brain stem nuclei. CONCLUSION: The authors' experiences suggest that neuronavigation, which displays 3-dimensional reconstructions of lesion, vessels, nerves and fiber tracts during surgery and makes use of image fusion techniques, is an important tool in the neurosurgical management of skull base lesions.

Adolescent↗
PubMed2006

Effectiveness of neuronavigation in resecting solitary intracerebral contrast-enhancing tumors: a randomized controlled trial.

OBJECT: The goal of this study was to assess the impact of neuronavigation on the cytoreductive treatment of solitary contrast-enhancing intracerebral tumors and outcomes of this treatment in cases in which neuronavigation was preoperatively judged to be redundant. METHODS: The authors conducted a prospective randomized study in which 45 patients, each harboring a solitary contrast-enhancing intracerebral tumor, were randomized for surgery with or without neuronavigation. Peri- and postoperative parameters under investigation included the following: duration of the procedure; surgeon's estimate of the usefulness of neuronavigation; quantification of the extent of resection, determined using magnetic resonance imaging; and the postoperative course, as evaluated by neurological examinations, the patient's quality-of-life self-assessment, application of the Barthel index and the Karnofsky Performance Scale score, and the patient's time of death. The mean amount of residual tumor tissue was 28.9% for standard surgery (SS) and 13.8% for surgery involving neuronavigation (SN). The corresponding mean amounts of residual contrast-enhancing tumor tissue were 29.2 and 24.4%, respectively. These differences were not significant. Gross-total removal (GTR) was achieved in five patients who underwent SS and in three who underwent SN. Median survival was significantly shorter in the SN group (5.6 months compared with 9 months, unadjusted hazard ratio = 1.6); however, this difference may be attributable to the coincidental early death of three patients in the SN group. No discernible important effect on the patients' 3-month postoperative course was identified. CONCLUSIONS: There is no rationale for the routine use of neuronavigation to improve the extent of tumor resection and prognosis in patients harboring a solitary enhancing intracerebral lesion when neuronavigation is not already deemed advantageous because of the size or location of the lesion.

Aged↗
PubMed2000

Neuronavigation in surgery of intracranial and spinal tumors.

PURPOSE: To demonstrate the new possibilities and advantages of neuronavigation in the surgery of intracranial and spinal tumors, based on patient populations treated in our hospital. MATERIALS AND METHODS: An infrared navigation system with integrated microscope guidance was used for frameless intracranial neuronavigation. The biopsies of intracranial tumors were carried out using a frame-based stereotactic technique. Intracranial navigation was, in part, combined with the use of an intraoperative CT scanner and a three-dimensional ultrasound system for data acquisition, correction of brain shifts, and intraoperative quality control. The navigation was also supported by presurgical brain mapping with magnetic source imaging. Navigation in spinal surgery was exclusively performed using an infrared navigation system in combination with an intraoperative CT scanner. RESULTS: The stereotactic tumor biopsies (n = 57) were carried out with an accuracy of 91.4% as compared with the histological diagnosis. The work flow of stereotactic procedures could be increased by using the intraoperative CT scanner. Fifty-seven patients with intracranial tumors were treated with the aid of neuronavigation between July 1997 and December 1999. These patients showed an improvement from 80% to 86% on the Karnofsky index 8 weeks postoperatively. The majority of intracranial cases were primary brain tumors (n = 30) and metastases (n = 13) in functionally important areas of the brain. In four patients, a significant brain shift was observed during neuronavigation, and could be corrected by an image update using either the intraoperative CT scanner (n = 2) or the three-dimensional ultrasound system (n = 2). The presurgical brain mapping with magnetoencephalography was shown to be reliable in the sensory cortex (n = 25). Eleven patients with a thoracic or lumbar tumor were treated by open surgery or stabilization, using a combination of spinal neuronavigation and the intraoperative CT scanner. Two patients with spinal tumors underwent navigated biopsies. Neither of them showed a reduction in the clinical stage, but the Karnofsky index improved from 63% up to 72% 8 weeks postoperatively. CONCLUSION: Neuronavigation allows very precise intracranial and spinal surgery. The problem of brain shift during the navigation procedures has been solved by intraoperative image acquisition. The use of neuronavigation was shown to improve the postoperative quality of life of patients suffering from brain and spinal tumors.

Adult↗
PubMed2000

Virtual pointer projection of the central sulcus to the outside of the skull using frameless neuronavigation -- accuracy and applications.

BACKGROUND: The purpose of this prospective study was to localize the central sulcus by frameless neuronavigation and to project this anatomical structure to the outside of the skull on the skin. This method was analyzed in respect to its practicability, accuracy, and potential applications. METHOD: In 27 patients investigated (28 unaffected hemispheres), the central sulcus was virtually projected to the outside of the skull using frameless neuronavigation and a virtual pointer elongation of 15 or 20 mm. The following parameters were measured on the scalp: 1. the distance between the bregma and the midline junction of the central sulcus, and 2. the angle between the central sulcus and the midline. These dada were compared with measurements based on the original axial MR images of these patients. Finally, a laboratory phantom study was designed in analogy to a patient's examination for estimation of the overall accuracy of the neuronavigation system in the experimental setup used in this study. FINDINGS: Virtual pointer projection of the central sulcus to the outside of the skull using frameless neuronavigation was found to be easily possible. The distance between the bregma and the midline junction of the central sulcus amounted to a mean of 55 mm on the left and 56 mm on the right. The angle between the central sulcus and the midline reached a mean of 63 degrees on the left and 60 degrees on the right. These data confirmed results of other studies with no frameless neuronavigation devices. The phantom study revealed a mean overall inaccuracy of 0.9 mm at a virtual pointer elongation of 15 mm. At a virtual pointer elongation of 20 mm, the mean overall inaccuracy of our study was 1.1 mm. These results correspond to the inaccuracy of frame based stereotaxy. INTERPRETATION: It is easily possible, valid, and reliable to virtually project the central sulcus to the outside of the skull with an acceptably low inaccuracy using frameless neuronavigation. This is important for research studies that correlate and integrate different functional imaging methods with the aid of frameless neuronavigation.

Adult↗
PubMed2001

Frameless neuronavigation in intracranial endoscopic neurosurgery.

OBJECT: Frameless computerized neuronavigation has been increasingly used in intracranial endoscopic neurosurgery. However, clear indications for the application of neuronavigation in neuroendoscopy have not yet been defined. The purpose of this study was to determine in which intracranial neuroendoscopic procedures frameless neuronavigation is necessary and really beneficial compared with a free-hand endoscopic approach. METHODS: A frameless infrared-based computerized neuronavigation system was used in 44 patients who underwent intracranial endoscopic procedures, including 13 third ventriculostomies, nine aqueductoplasties, eight intraventricular tumor biopsy procedures or resections, six cystocistemostomies in arachnoid cysts, five colloid cyst removals, four septostomies in multiloculated hydrocephalus, four cystoventriculostomies in intraparenchymal cysts, two aqueductal stent placements, and fenestration of one pineal cyst and one cavum veli interpositi. All interventions were successfully accomplished. In all procedures, the navigational system guided the surgeons precisely to the target. Navigational tracking was helpful in entering small ventricles, in approaching the posterior third ventricle when the foramen of Monro was narrow, and in selecting the best approach to colloid cysts. Neuronavigation was essential in some cystic lesions lacking clear landmarks, such as intraparenchymal cysts or multiloculated hydrocephalus. Neuronavigation was not necessary in standard third ventriculostomies, tumor biopsy procedures, and large sylvian arachnoid cysts, or for approaching the posterior third ventricle when the foramen of Monro was enlarged. CONCLUSIONS: Frameless neuronavigation has proven to be accurate, reliable, and extremely useful in selected intracranial neuroendoscopic procedures. Image-guided neuroendoscopy improved the accuracy of the endoscopic approach and minimized brain trauma.

Adolescent↗
PubMed2005

Neuronavigational neuroendoscopic surgery. Frameless free-hand maneuvering of a handy rigid-rod neuroendoscope on visualized three-dimensional computerized image guidance: trajectory to the prepontine cistern in cadaver study.

BACKGROUND: Considering the separate benefits of neuronavigation and neuroendoscopy, neuroendoscopic surgery with the aid of neuronavigation systems will play an increasingly important role in the future. Bearing this in mind, the present research project was conducted to facilitate neuronavigational neuroendoscopic surgery along the pathway to the prepontine cistern using cadaver heads. MATERIALS AND METHODS: A computer-aided, frameless image-guided stereotactic navigation system and a new type of handy rigid-rod neuroendoscope were used. The ideal entry point and the safest trajectory to the prepontine cistern through the foramen of Monro were defined in two formalin-fixed cadaver heads and clinical brain MRI data. Then, maneuvering of the neuroendoscope with the aid of the neuronavigation system was performed. RESULTS: Straight trajectories from the entry point to the prepontine cistern could be designed. For the registration accuracy of the tip of the neuroendoscope, the virtual image registered a mean error distance of 5.42 mm away from the reference point along the axis of vertical line. However, free-hand maneuvering enabled the neuroendoscope to be finely manipulated without damaging brain tissues. Neuroendoscopic anatomical views of the interpeduncular and prepontine cistern were also acquired. CONCLUSION: Interactive use of free-hand maneuvering of the handy rigid-rod neuroendoscope together with frameless neuronavigation systems plot the way to true neuronavigational neuroendoscopic surgery in a safe and reliable manner. This pairing of the most recent technological neurosurgical options with better understanding of neuroendoscopic anatomy enables the neurosurgeon to acquire broader treatment options for central nervous system diseases.

Adult↗
PubMed2005

The impact of auditory feedback on neuronavigation.

OBJECT: We aimed to develop an auditory feedback system to be used in addition to regular neuronavigation, in an attempt to improve the usefulness of the information offered by neuronavigation systems. INSTRUMENTATION: Using a serial connection, instrument co-ordinates determined by a commercially available neuronavigation system were transferred to a laptop computer. Based on preoperative segmentation of the images, the software on the laptop computer produced an audible signal whenever the instrument moved into an area the surgeon wanted to avoid. METHODS: To evaluate the impact of our setup on volumetric resections, phantom experiments were conducted. CT scans were acquired from eight blocks of floral foam. In each of these scans, a target-volume was segmented. This target-volume was subsequently resected using either regular neuronavigation or neuronavigation extended with auditory feedback. A 'postoperative' CT scan was used to compare the resection cavity to the preoperatively planned target-volume. FINDINGS: The resemblance between the resection cavity and the target-volume was greater each time auditory feedback had been used. This corresponded with more complete removal of the target-volume. However, it also corresponded with the removal of more non-target 'tissue' in two out of four cases. CONCLUSIONS: The usefulness of auditory feedback was made plausible and the use of a new type of navigation phantom was illustrated. Based on these results, we recommend incorporation of auditory feedback in commercially available neuronavigation systems, especially since this is relatively inexpensive.

Acoustic Stimulation↗
PubMed2004

Neuronavigation-guided endoscopic surgery for pineal tumors with hydrocephalus.

We have applied the neuronavigation system to endoscopic biopsy and third ventriculostomy in the management of patients with a pineal tumor with hydrocephalus. With the guidance of neuronavigation, the two optimal sites of burr hole and trajectories were planned preoperatively, and the advancing endoscopic device was monitored in real time during the procedure. In our five patients, the diameters of the tumors were 2-3 cm, and the mean systemic accuracy of registration with neuronavigation was 1.2 mm. The biopsy and third ventriculostomy were performed successfully via the respective optimal burr hole and the trajectory determined using preoperative neuronavigation. There were no procedure-related complications, and none of the patients needed another procedure for CSF diversion during the follow-up periods. We present our technique which includes the application of the neuronavigation system to the biopsy and third ventriculostomy in pineal tumor with associated hydrocephalus. This technique can be performed using a simple rigid endoscope via the determined optimal entries and trajectories. The optimal preoperative planning and the intraoperative guidance by neuronavigation are thought to be able to give more chances to minimize the brain injury related to movements or deviation of endoscopic device.

Adolescent↗
PubMed2002

Neuronavigation: concept, techniques and applications.

Neuronavigation provides intraoperative orientation to the surgeon, helps in planning a precise surgical approach to the targetted lesion and defines the surrounding neurovascular structures. Incorporation of the functional data provided by functional MRI and magnetoencephalography (MEG) with neuronavigation helps to avoid the eloquent areas of the brain during surgery. An intraoperative MRI enables radical resection of the lesions, the possibility of immediate control for tumor remnants and updates of neuronavigation with intraoperative images to compensate for brain shift. In this study, the experience of 432 patients undergoing neuronavigation assisted neurosurgical interventions using either the pointer-based or microscope-based navigational systems at the University of Erlangen-Nuremberg, Germany is presented. The procedures included stereotactic biopsy (n=53), stereotactic cyst puncture/ventricular drainage (n=15), eloquent cortex/tumor localization to facilitate tumor resection, assessment of neurovascular structures in the vicinity of tumors of the sellar-suprasellar regions, skull base, posterior fossa and ventricular region (n=252), and, surgery for epilepsy (n=9). Functional brain mapping using fMRI and MEG and their integration with neuronavigation was carried out in 24 and 128 patients respectively. The simultaneous use of intraoperative MRI to look for the remaining tumor was done in 159 patients and the update of navigational data was carried out in 17 patients. The mean system accuracy obtained by using both the fiducial registration as well as anatomical landmark-surface fitting computer algorithm was 1.81 mm. This study reviews the relative merits and demerits of the pointer and microscope based navigational systems and also highlights the role of functional brain mapping and intraoperative MRI, when integrated with neuronavigation, in the surgical decision-making to offer the chances of more radical resections with minimal morbidity.

Adolescent↗
PubMed1999

[Neuronavigation. Computer-assisted neurosurgery].

The use of stereotactic methods for the resection of subcortical lesions is heavily advocated in clinical neurosurgery introducing the term "neuronavigation". Though being an unequivocally elegant technique for the localisation and delineation of pathological lesions in the central nervous system neuronavigation has not been validated by any prospective randomized controlled trial. The method is prone to significant errors as to the intraoperative localisation based upon preoperative three-dimensional images. The maximum error can be up to 2.6 cm depending on the extent of the so-called brain shift. In comparison classical frame based stereotaxy has a mean error of +/- 1 mm and remains the gold standard for the exact three-dimensional localisation of a given lesion. The value of neuronavigation is evident for small deep seated vascular lesions. For metastatic tumors or skull base tumors the usefulness is rather marginal because alternative therapies are available with proven and equivalent efficacy and reduced morbidity on one hand, and because of the anatomy of the tumor which makes neuronavigation unnecessary. For the currently most common application of neuronavigation, i.e. surgery of gliomas, no significant improvements of therapeutic results can be expected from neuronavigation. The biology of gliomas limits any mechanical approaches.

Brain Neoplasms↗
PubMed2000

Intraoperative imaging with open magnetic resonance imaging and neuronavigation.

The Erlangen-concept of image-guided-surgery is based on the installation of an open magnetic resonance (MR) scanner (Magnetom Open, 0.2 T, Siemens AG) in a twin operating room in combination with two neuronavigation systems (Stealth NeuroStation, Sofamor Danek, MKM Zeiss). Since March 1996 this method has been used for a total of 402 patients, among them 44 children. In 214 patients, mainly with gliomas or pituitary adenomas or who needed surgery for epilepsy, we performed intraoperative MR imaging to monitor the extent of resection, allowing a second look for possible tumor remnants and also compensating for brain shift by an intraoperative update of neuronavigation. Functional neuronavigation, i.e. the combination of anatomical neuronavigation with functional imaging [e.g. magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI)] was used in patients with lesions in brain areas such as the motor and speech areas. For MEG we used a MAGNES II biomagnetometer (Biomagnetic Technologies, San Diego, Calif.) and for fMRI a 1.5 T Siemens Symphony MR scanner. So far we have treated 89 patients with functional neuronavigation. Our preliminary experience indicates that intraoperative MR imaging, especially in combination with functional neuronavigation, allows more radical resections with lower morbidity.

Adenoma↗
PubMed2006

Neuronavigator-guided percutaneous radiofrequency thermocoagulation in the treatment of intractable trigeminal neuralgia.

BACKGROUND: Percutaneous radiofrequency thermocoagulation of the trigeminal ganglion (PRTTG) is regarded as the first choice for most patients with trigeminal neuralgia (TN) because of its safety and feasibility. However, neuronavigator-guided PRTTG has been seldom reported. The purpose of this study was to assess the safety and efficacy of neuronavigator-guided PRTTG for the treatment of intractable TN. METHODS: Between January 2000 and December 2004, 54 patients with intractable TN were enrolled into this study and were randomly divided into two groups. The patients in navigation group (n = 26) underwent PRTTG with frameless neuronavigation, and those in control group (n = 28) received PRTTG without neuronavigation. Three months after the operation, the efficacy, side effects, and complications of the surgery were recorded. The patients in the control group were followed up for 10 to 54 months (mean, 34 +/- 5), and those in the navigation group were followed up for 13 to 58 months (mean, 36 +/- 7). Kaplan-Meier analyses of the pain-free survival curves were used for the censored survival data, and the log-rank test was used to compare survival curves of the two groups. RESULTS: The immediate complete pain-relief rate of the navigation group was 100%, whereas it was 95% in the control. The proportion of sustained pain-relief rates at 12, 24 and 36 months after the procedure were 85%, 77%, and 62% in the navigation group, and 54%, 40%, and 35% in the control. Recurrences in the control group were more common than that in the navigation group. Annual recurrence rate in the first and second years were 15% and 23% in the navigation group, and 46%, 60% in the control group. No side-effect and complication was noted in the navigation group except minimal facial hypesthesia. CONCLUSION: Neuronavigator-guided PRTTG is a safe and promising method for treatment of intractable TN with better short- and long-term outcomes and lower complication rate than PRTTG without neuronavigation.

Aged↗
PubMed2002

Accuracy evaluation of a 3D ultrasound-based neuronavigation system.

We have investigated the 3D navigation accuracy of a frameless ultrasound-based neuronavigation system (SonoWand) for surgical planning and intraoperative image guidance. In addition, we present a detailed description and review of the error sources associated with surgical neuronavigation based on preoperative MRI data and intraoperative ultrasound. A phantom with 27 precisely defined points was scanned with ultrasound by various translation and tilt movements of the ultrasound probe (180 3D scans in total), and the 27 image points in each volume were located using an automatic detection algorithm. These locations were compared to the physically measured locations of the same 27 points. The accuracy of the neuronavigation system and the effect of varying acquisition conditions were found through a thorough statistical analysis of the differences between the two point sets. The accuracy was found to be 1.40 +/- 0.45 mm (arithmetic mean) for the ultrasound-based neuronavigation system in our laboratory setting. Improper probe calibration was the major contributor to this figure. Based on our extensive data set and thorough evaluation, the accuracy found in the laboratory setting is expected to be close to the overall clinical accuracy for ultrasound-based neuronavigation. Our analysis indicates that the overall clinical accuracy may be as low as 2 mm when using intraoperative imaging to compensate for brain shift.

Humans↗