Intraoperative Multi-Information-Guided Resection of Dominant-Sided Insular Gliomas in a 3-T Intraoperative Magnetic Resonance Imaging Integrated Neurosurgical Suite.

OBJECTIVE: To evaluate the clinical application of 3-T intraoperative magnetic resonance imaging (iMRI), awake craniotomy, multimodal functional mapping, and intraoperative neurophysiologic monitoring (IONM) for resection of dominant-sided insular gliomas. METHODS: From March 2011 to June 2013, 30 gliomas involving the dominant insular lobe were resected in the IMRIS 3.0-T iMRI integrated neurosurgical suite. For 20 patients, awake craniotomy with cortical electrical stimulation mapping was performed to locate the language areas. For 10 patients who were not suitable for awake surgery, general anesthesia and functional navigation were performed. Diffusion tensor imaging tractography-based navigation, continuous motor evoked potential monitoring, and subcortical electrical stimulation mapping were applied to localize and monitor the motor pathway in all cases. iMRI was used to assess the extent of resection. The results of intraoperative imaging, IONM, and the surgical consequences were analyzed. RESULTS: Intraoperative imaging revealed residual tumor in 26 cases and led to further resection in 9 cases. As a result, the median extent of resection was increased from 90% to 93% (P = 0.008) in all cases, and from 88% to 92% (P = 0.018) in low-grade gliomas. The use of iMRI also resulted in an increase in the percentage of gross and near total resection from 53% to 77% (P = 0.016). The rates of permanent language and motor deficits resulting from tumor removal were 11% and 7.1%, respectively. CONCLUSIONS: The combination of iMRI, awake craniotomy, multimodal brain mapping, and IONM tailored for each patient permits the maximal safe resection of dominant-sided insular glioma.

Localizing hand motor area using resting-state fMRI: validated with direct cortical stimulation.

BACKGROUND: Resting-state functional magnetic resonance imaging (R-fMRI) is a promising tool in clinical application, especially in presurgical mapping for neurosurgery. This study aimed to investigate the sensitivity and specificity of R-fMRI in the localization of hand motor area in patients with brain tumors validated by direct cortical stimulation (DCS). We also compared this technique to task-based blood oxygenation level-dependent (BOLD) fMRI (T-fMRI). METHODS: R-fMRI and T-fMRI were acquired from 17 patients with brain tumors. The cortex sites of the hand motor area were recorded by DCS. Site-by-site comparisons between R-fMRI/T-fMRI and DCS were performed to calculate R-fMRI and T-fMRI sensitivity and specificity using DCS as a "gold standard". R-fMRI and T-fMRI performances were compared statistically RESULTS: A total of 609 cortex sites were tested with DCS and compared with R-fMRI findings in 17 patients. For hand motor area localization, R-fMRI sensitivity and specificity were 90.91 and 89.41 %, respectively. Given that two subjects could not comply with T-fMRI, 520 DCS sites were compared with T-fMRI findings in 15 patients. The sensitivity and specificity of T-fMRI were 78.57 and 84.76 %, respectively. In the 15 patients who successfully underwent both R-fMRI and T-fMRI, there was no statistical difference in sensitivity or specificity between the two methods (p = 0.3198 and p = 0.1431, respectively) CONCLUSIONS: R-fMRI sensitivity and specificity are high for localizing hand motor area and even equivalent or slightly higher compared with T-fMRI. Given its convenience for patients, R-fMRI is a promising substitute for T-fMRI for presurgical mapping.

Sensorimotor cortical changes assessed with resting-state fMRI following total brachial plexus root avulsion.

OBJECTIVE: Peripheral nerve injury can induce immediate and long-standing remodelling of the brain cortex, which may affect outcomes of nerve repair. This study examined changes of corresponding cortical representations in patients with brachial plexus injuries. METHODS: Resting-state fMRI was acquired for 13 adult patients with total brachial plexus root avulsion, three of whom underwent second scans 7 or 8 months later. The time of examination ranged from 1 to 16 months after injuries. Nine healthy adults were enrolled as control. Seed-based functional connectivity was performed for all subjects. RESULTS: For nine patients whose first fMRI was performed from 1 to 4 months after brachial plexus injuries, images showed that their cortical maps of sensorimotor areas corresponding to the hand and arm in the hemisphere contralateral to the injured side had much weaker correlation with the supplementary motor area (SMA) than those ipsilateral to the injured side. Symmetrical maps of bilateral cortical sensorimotor areas corresponding to the hand and arm were observed in other four cases with fMRI tested from 7 to 16 months after injuries. For three of the nine patients with asymmetrical cortical representations, second scans indicated symmetric results or even stronger correlation with SMA in the cerebral cortex contralateral to the injured side. CONCLUSIONS: Total brachial plexus root avulsion causes cortical representations of the brachial plexus to undergo a change from an inactive to an active state. This implies that peripheral deafferentation after brachial plexus injuries will induce corresponding cortical representations to be occupied by adjacent non-deafferented cortical territories.

Clinical experience of 3T intraoperative magnetic resonance imaging integrated neurosurgical suite in Shanghai Huashan Hospital.

BACKGROUND: Intraoperative magnetic resonance imaging (iMRI) dates back to the 1990s and has been successfully applied in neurosurgery but they were low-field iMRI (< 1.0T). This paper reports the clinical experience with a 3T iMRI-integrated neurosurgical suite in Huashan Hospital, Shanghai, China. METHODS: From September 2010 through March 2012, 373 consecutive patients underwent neurological surgery under guidance with 3T iMRI. A retrospective analysis was conducted regarding clinical efficiency. RESULTS: All surgery in the 373 patients was safe. The ratio of gross total resection for cerebral gliomas (n = 161) was increased from 55.90% to 87.58%. The ratio of benefit in extent of resection was 39.13%. One hundred and fifty eight of the 161 glioma patients accomplished follow-up at 3 months postoperatively. Twenty of 161 patients (12.42%) suffered from early motor deficit after surgery. Late motor deficit was however observed in five of 158 patients (3.16%). Twenty-one of 161 patients (13.04%) had early speech deficit and late speech deficit was only observed in six of 158 patients (3.80%). The ratio of gross total resection for pituitary adenomas (n = 49) was increased from 77.55% to 85.71%. The ratio of benefit in extent of resection was 10.2%. There were no iMRI-related adverse events even for patients who underwent awake craniotomy. CONCLUSION: The 3T iMRI integrated neurosurgical suite provides high-quality intraoperative structural and functional imaging for real-time tumor resection control and accurate functional preservation, resulting in an improvement in maximal safe brain surgery.

"Awake" intraoperative functional MRI (ai-fMRI) for mapping the eloquent cortex: Is it possible in awake craniotomy?

As a promising noninvasive imaging technique, functional MRI (fMRI) has been extensively adopted as a functional localization procedure for surgical planning. However, the information provided by preoperative fMRI (pre-fMRI) is hampered by the brain deformation that is secondary to surgical procedures. Therefore, intraoperative fMRI (i-fMRI) becomes a potential alternative that can compensate for brain shifts by updating the functional localization information during craniotomy. However, previous i-fMRI studies required that patients be under general anesthesia, preventing the wider application of such a technique as the patients cannot perform tasks unless they are awake. In this study, we propose a new technique that combines awake surgery and i-fMRI, named "awake" i-fMRI (ai-fMRI). We introduced ai-fMRI to the real-time localization of sensorimotor areas during awake craniotomy in seven patients. The results showed that ai-fMRI could successfully detect activations in the bilateral primary sensorimotor areas and supplementary motor areas for all patients, indicating the feasibility of this technique in eloquent area localization. The reliability of ai-fMRI was further validated using intraoperative stimulation mapping (ISM) in two of the seven patients. Comparisons between the pre-fMRI-derived localization result and the ai-fMRI derived result showed that the former was subject to a heavy brain shift and led to incorrect localization, while the latter solved that problem. Additionally, the approaches for the acquisition and processing of the ai-fMRI data were fully illustrated and described. Some practical issues on employing ai-fMRI in awake craniotomy were systemically discussed, and guidelines were provided.

[Preliminary application of 3.0 T intraoperative magnetic resonance imaging neuronavigation system in China].

OBJECTIVE: To report the preliminary experience in clinical application of 3.0 T intraoperative magnetic resonance imaging (iMRI) neuronavigation system in China. METHODS: From September 2010 to March 2011, a consecutive series of 122 patients with intracranial lesions underwent operations in guidance with 3.0 T iMRI. A retrospective analysis was conducted regarding clinical efficiency. RESULTS: Among 122 procedures, the numbers of intraoperative scanning were 2 - 4 times with an average of 2.6. The qualities of images were excellent. Due to the discovery and further possibility of resection of residual tumors, the ratio of gross total resection was increased from 71.7% to 90.0% in cerebral gliomas (n = 60), while from 75.9% to 93.1% in macroadenomas (n = 29). There were 6.7% of all patients occurred postoperative paralysis, but only 3.3% of patients had persistent paralysis at 1 - 2 months follow-up. There was no iMRI-related adverse event occurred. During the same period, more than 2500 patients underwent diagnostic MRI scanning. CONCLUSIONS: 3.0 T iMRI neuronavigation system provides high-quality intraoperative structural, functional and metabolic images for real time tumor resection control and accurate functional preservation, resulting in an improvement in maximal safe brain surgery. The system is cost-effective.

[Awake craniotomy and intraoperative language cortical mapping for eloquent cerebral glioma resection: preliminary clinical practice in 3.0 T intraoperative magnetic resonance imaging integrated surgical suite].

OBJECTIVES: To evaluate preliminary clinical experience for combining awake craniotomy and intraoperative language brain mapping within the integrated 3.0 T intraoperative magnetic resonance imaging (iMRI) suite. METHODS: From December 2010 to April 2011, 11 right hand-dominant patients with left glioma were involved in, or adjacent to, eloquent cortex was carried out awake craniotomies with cortical stimulation within an integrated 3.0 T iMRI suite. Aphasia battery of Chinese was used to test the language function before the operation. During the procedure, after the occipital, temporal, and supraorbital nerves were blocked by the anesthesiologists, the head was fixed with a custom high-field MRI-compatible head holder. The skull and dura was opened as usual and language brain mapping was then performed. Language testing followed a set protocol: counting numbers from 1 to 50, naming objects, reading single words. Resection of the tumor was guided by neuronavigation system and continued until eloquent areas were encountered or the margin of assessment was reached. An interdissection MRI was acquired to evaluate the glioma removal in a movable MRI scanner after minimal draping. Meanwhile, adverse effects caused by electrical stimulation and iMRI were recorded. The follow-up speech tests were assessed on 7th day and 1 month at least after the operation. RESULTS: The combined use of 3.0 T iMRI and awake craniotomy was performed safely in all patients. No adverse effects were reported. The duration of surgery was prolonged by 2 to 4 h. The patients' perception of iMRI during surgery was favorable. First-look MRI studies led to further resection attempts in 6/11 cases as well as a 3/11 increase in the number of gross-total resections. One week after surgery, baseline language function worsened in 4 cases. However, no patients had a persistent language deficit one month after surgery. CONCLUSIONS: Awake craniotomy and direct cortical electrical stimulation can be performed safely and effectively within a 3.0 T iMRI suite. The combination of high-field iMRI and awake craniotomy may facilitate safe removal of eloquent glioma.

Current status of cerebral glioma surgery in China.

The treatment of gliomas is highly individualized. Surgery for gliomas is essentially for histological diagnosis, to alleviate mass effect, and most importantly, to favor longer survival expectancy. During the past two decades, many surgical techniques and adjuvants have been applied to glioma surgery in China, which lead to a rapid development in the field of cerebral glioma surgery. This article broadly and critically reviewed the existing studies on cerebral glioma surgery and to portrait the current status of glioma surgery in China. A literature search was conducted covering major innovative surgical techniques and adjuvants for glioma surgery in China. The following databases were searched: the Pubmed (January 1995 to date); China Knowledge Resource Integrated Database (January 1995 to date) and VIP Database for Chinese Technical Periodicals (January 1995 to date). A selection criterion was established to exclude duplicates and irrelevant studies. The outcome measures were extracted from included studies. A total of 3307 articles were initially searched. After excluded by abstracts and full texts, 69 studies conducted in the mainland of China were included and went through further analysis. The philosophy of surgical strategies for cerebral gliomas in China is undergoing tremendous change. Nowadays Chinese neurosurgeons pay more attention to the postoperative neurofunctional status of the patients. The aim of the glioma surgery is not only the more extensive tumor resection but also the maximal safety of intervention. The well balance of longer overall survival and higher quality of life should be judged with respect to each individual patient.

Virtual reality presurgical planning for cerebral gliomas adjacent to motor pathways in an integrated 3-D stereoscopic visualization of structural MRI and DTI tractography.

OBJECTIVE: Resection of gliomas invading primary motor cortex and subcortical motor pathway is difficult in both surgical decision-making and functional outcome prediction. In this study, magnetic resonance (MR) diffusion tensor imaging (DTI) data were used to perform tractography to visualize pyramidal tract (PT) along its whole length in a stereoscopic virtual reality (VR) environment. The potential value of its clinical application was evaluated. METHODS: Both three-dimensional (3-D) magnetic resonance imaging (MRI) and DTI datasets were obtained from 45 eligible patients with suspected cerebral gliomas and then transferred to the VR system (Dextroscope; Volume Interactions Pte. Ltd., Singapore). The cortex and tumor were segmented and reconstructed via MRI, respectively, while the tractographic PTs were reconstructed via DTI. All those were presented in a stereoscopic 3-D display synchronously, for the purpose of patient-specific presurgical planning and surgical simulation in each case. The relationship between increasing amplitude of the number of effective fibers of PT (EPT) at affected sides and the patients' Karnofsky Performance Scale (KPS) at 6 months was addressed out. RESULTS: In VR presurgical planning for gliomas, surgery was aided by stereoscopic 3-D visualizing the relative position of the PTs and a tumor. There was no significant difference between pre- and postsurgical EPT in this population. A positive relationship was proved between EPT increasing amplitude and 6-month KPS. CONCLUSIONS: 3-D stereoscopic visualization of tractography in this VR environment enhances the operators to well understand the anatomic information of intra-axial tumor contours and adjacent PT, results in surgical trajectory optimization initially, and maximal safe tumor resection finally. In accordance to the EPT increasing amplitude, surgeon can predict the long-term motor functional outcome.