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Background: Awake craniotomy paired with intraoperative magnetic resonance imaging (iMRI) is now the established technique for maximizing surgical resection, while preserving neurological function. However, leaving an unsecured airway patient in the iMRI gantry represents considerable risk. Our study aimed at identifying the incidence of critical adverse events in unsecured airway patients during iMRI as part of awake craniotomy., Materials and Methods: We conducted a clinical chart review of consecutive awake craniotomies performed between November 1999 and December 2015. Sequences of iMRI performed without invasive airway management were selected for assessment and the incidence of critical adverse events, including general convulsive seizure, respiratory arrest, nausea/vomiting and agitation, was identified., Results: Critical adverse events occurred in 21 of 356 unsecured airway patients within 24 of the 579 iMRI sequences. In cases using the low-field strength open MRI scanner, emergency termination of scans due to patient decline was recorded in only 4 cases: no cases of cardiac arrest, accidental death, or thermal injury were recorded. Compared with cardiovascular monitoring, patient respiratory status was poorly recorded., Conclusions: In terms of anesthesia, concurrent use of iMRI for awake craniotomy is clinically acceptable providing potential intraoperative complications can be controlled. Further, the configuration of the iMRI scanner as well as the reduced exposure from the lower magnetic field strength was found to impact patient safety management. Therefore when a conscious patient is left in the gantry without airway support, it is advisable that levels of oxygenation and ventilation should be monitored at all times.

OBJECTIVE WHO Grade III gliomas are relatively rare and treated with multiple modalities such as surgery, chemotherapy, and radiotherapy. The impact of the extent of resection (EOR) on improving survival in patients with this tumor type is unclear. Moreover, because of the heterogeneous radiological appearance of Grade III gliomas, the MRI sequence that best correlates with tumor volume is unknown. In the present retrospective study, the authors evaluated the prognostic significance of EOR. METHODS Clinical and radiological data from 122 patients with newly diagnosed WHO Grade III gliomas who had undergone intraoperative MRI-guided resection at a single institution between March 2000 and December 2011 were analyzed retrospectively. Patients were divided into 2 groups by histological subtype: 81 patients had anaplastic astrocytoma (AA) or anaplastic oligoastrocytoma (AOA), and 41 patients had anaplastic oligodendroglioma (AO). EOR was calculated using pre- and postoperative T2-weighted and contrast-enhanced T1-weighted MR images. Univariate and multivariate analyses were performed to evaluate the prognostic significance of EOR on overall survival (OS). RESULTS The 5-, 8-, and 10-year OS rates for all patients were 74.28%, 70.59%, and 65.88%, respectively. The 5- and 8-year OS rates for patients with AA and AOA were 72.2% and 67.2%, respectively, and the 10-year OS rate was 62.0%. On the other hand, the 5- and 8-year OS rates for patients with AO were 79.0% and 79.0%; the 10-year OS rate is not yet available. The median pre- and postoperative T2-weighted high-signal intensity volumes were 56.1 cm 3 (range 1.3-268 cm 3 ) and 5.9 cm 3 (range 0-180 cm 3 ), respectively. The median EOR of T2-weighted high-signal intensity lesions (T2-EOR) and contrast-enhanced T1-weighted lesions were 88.8% (range 0.3%-100%) and 100% (range 34.0%-100%), respectively. A significant survival advantage was associated with resection of 53% or more of the preoperative T2-weighted high-signal intensity volume in patients with AA and AOA, but not in patients with AO. Univariate analysis showed that preoperative Karnofsky Performance Scale score (p = 0.0019), isocitrate dehydrogenase 1 ( IDH1) mutation (p = 0.0008), and T2-EOR (p = 0.0208) were significant prognostic factors for survival in patients with AA and AOA. Multivariate analysis demonstrated that T2-EOR (HR 3.28; 95% CI 1.22-8.81; p = 0.0192) and IDH1 mutation (HR 3.90; 95% CI 1.53-10.75; p = 0.0044) were predictive of survival in patients with AA and AOA. CONCLUSIONS T2-EOR was one of the most important prognostic factors for patients with AA and AOA. A significant survival advantage was associated with resection of 53% or more of the preoperative T2-weighted high-signal intensity volume in patients with AA and AOA.

Background: Transient focal magnetic resonance imaging (MRI) abnormalities after status epilepticus (SE) are rarely seen in patients with benign brain tumors, and the underlying mechanism is still unknown. We report a rare case of cerebral cavernous malformation with transient focal MRI abnormalities around the tumor and accumulation of 11C-methionine on positron emission tomography (PET) after SE. These findings mimicked those of a glioma because the MRI and methionine PET findings were similar. We also speculate about the cause of this phenomenon in relation to pathologic findings of this case., Case Description: A 51-year-old man suffered from SE. MRI demonstrated a focal T2/fluid-attenuated inversion recovery hyperintense area. 11C-methionine PET showed high accumulation of methionine in the same lesion. The initial diagnosis was low-grade glioma. However, these MRI abnormalities were transient and completely resolved. The patient underwent surgical removal of the tumor, and the histologic diagnosis was typical cavernous malformation. Pathologic findings of the gyrus around the tumor revealed mild gliosis with proliferating astrocytes but no evidence of glioma., Conclusions: This case suggests that transient focal MRI abnormalities after SE may indicate reversible cortical brain edema. Accumulation of 11C-methionine on PET could occur in the corresponding lesion even if no malignant tumor is present. Because distinguishing transient MRI abnormalities after SE from a glioma is difficult, repeated imaging studies should be performed in patients with brain tumor-related seizures., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Extent of resection (EOR) remains controversial in therapy for glioblastoma (GBM). However, an increasing number of studies favor maximum EOR as being associated with longer patient survival. Residual tumor volume (RTV) has also recently emerged as a prognostic factor. Low-field intraoperative magnetic resonance imaging (iMRI) has contributed to improve the EOR of GBM. The purpose of this study was to analyze the relationships between EOR/RTV and overall survival (OS)/progression-free survival (PFS) in patients with newly diagnosed GBM using low-field iMRI., Methods: Adult patients who underwent surgery for newly diagnosed supratentorial GBM between 2000 and 2012 were retrospectively reviewed. Three-dimensional volumetric tumor measurements were made. Multivariate analysis was used to evaluate the relationships between EOR/RTV and OS/PFS., Results: Of 168 patients, 126 (75%) died and 154 (91%) showed tumor recurrence. Median OS and PFS for patients with iMRI were 19.3 months (95% confidence interval, 15.4-23.7 months) and 9.5 months (95% confidence interval, 7.8-10.8 months). Median preoperative tumor volume was 37.0 cm 3 (interquartile range [IQR], 19.9-59.8 cm 3 ). Median RTV was 0 cm 3 (IQR, 0-1.6 cm 3 ). Median EOR was 100% (IQR, 96.2%-100%). In multivariate analysis, after controlling for age and Karnofsky Performance Status, EOR and RTV remained significantly associated with survival (hazard ratio, 1.56; P = 0.018) and recurrence (hazard ratio, 1.53; P = 0.013). Maximum RTV for survival was 3 cm 3 ., Conclusions: This volumetric analysis for low-field iMRI showed that both EOR and RTV were significantly associated with survival and recurrence. We determined a threshold RTV of 3 cm 3 as the maximum RTV associated with survival., (Copyright © 2016 Elsevier Inc. All rights reserved.)

This study examined the accuracy of functional magnetic resonance imaging (fMRI) in identifying the language-dominant hemisphere and the situations in which the Wada test can be skipped among patients with gliomas located near speech areas. We examined 74 patients [48 men (64.9%); mean ± standard deviation age of 42.7 ± 13.6 years (range: 13 to 70 years); 71 right-handed, 2 left-handed, and 1 ambidextrous] with gliomas located near speech areas. All patients underwent the Wada test and fMRI, and 34 patients underwent awake surgery. The "last-and-first" task was administered during fMRI. The Wada test was successful in determining the language-dominant hemisphere in 73 patients (98.6%): left hemisphere in 68 patients (91.9%), right hemisphere in 4 patients (5.4%), and bilateral in 1 patient (1.4%). The dominant hemisphere for right-handed patients (n = 71) was the left hemisphere in 67 patients (94.3%), right hemisphere in 3 patients (4.2%), and undetectable in 1 patient (1.4%). The fMRI was successful in determining the language-dominant hemisphere in 53 patients (71.6%). The results of the Wada test and fMRI were inconsistent in 5 patients (8.6%), of which 3 (5.2%) exhibited dominance in opposite hemispheres. Furthermore, 2 of these 3 cases (2.7%) were contralateral false positive cases, whereby fMRI identified the right-hemisphere as language dominant for right-handed individuals with tumors in the left hemisphere. Based on these findings, we concluded that the Wada test can be skipped if language dominancy can be detected by fMRI., Competing Interests: The authors have no financial conflicts of interests. All authors who are members of The Japan Neurological Society have registered online self-reported COI Disclosure Statement Forms through the JNS member website.

Background: During surgery, various images as well as other relevant visual information are usually shown upon request with the help of operating staff. However, the lack of direct control over the display may represent a source of stress for surgeons, particularly when fast decision making is needed., Objective: To present the development and initial clinical testing of an innovative device that enables surgeons to have direct intangible control of the intraoperative image-displaying monitor with standardized free-hand movements., Methods: The originally developed intangible interface named "OPECT" is based on the commercially available gaming controller KINECT (Microsoft) and dedicated action-recognizing algorithm. The device does not require any sensors or markers fixed on the hands. Testing was done during 30 neurosurgical operations. After each procedure, surgeons completed the 5-item questionnaire for evaluation of the system performance, scaling several parameters from 1 (bad) to 5 (excellent)., Results: During surgical procedures, OPECT demonstrated high effectiveness and simplicity of use, excellent quality of visualized graphics, and precise recognition of the individual user profile. In all cases, the surgeons were well satisfied with performance of the device. The mean score value of answers to the questionnaire was 4.7 ± 0.2., Conclusion: OPECT enables the surgeon to easily have intangible control of the intraoperative image monitor by using standardized free-hand movements. The system has promising potential to be applied for various kinds of distant manipulations with the displaying visual information during human activities.

Background: Contemporary technological developments revolutionized management of brain tumors. The experience with information-guided surgery of gliomas, based on the integration of the various intraoperative anatomical, functional, and histological data, is reported., Methods: From 2000 to 2009, 574 surgeries for intracranial gliomas were performed in our clinic with the use of intraoperative MRI (ioMRI) with magnetic field strength of 0.3T, updated neuronavigation, neurochemical navigation with 5-aminolevulinic acid, serial intraoperative histopathological investigations of the resected tissue, and comprehensive neurophysiological monitoring. Nearly half of patients (263 cases; 45.8%) were followed more than 2 years after surgery., Findings: Maximal possible tumor resection, defined as radiologically complete tumor removal or subtotal removal leaving the residual neoplasm within the vital functionally-important brain areas, was attained in 569 cases (99.1%). The median resection rate constituted 95%, 95%, and 98%, for WHO grade II, III, and IV gliomas, respectively. Actuarial 5-year survival was significantly worse in WHO grade IV gliomas (19%), but did not differ significantly between WHO grade III and II tumors (69% vs. 87%)., Conclusions: Information-guided management of gliomas using low-field-strength ioMRI provides a good opportunity for maximal possible tumor resection, and may result in survival advantage, particularly in patients with WHO grade III neoplasms.

Introduction: The present study was done for evaluation of the possible influence of the oral administration of choline on metabolic characteristics of gliomas detected with proton magnetic resonance spectroscopy ((1)H-MRS)., Materials and Methods: Thirty patients (22 men and eight women; mean age 38 +/- 15 years) with suspicious intracranial gliomas underwent single-voxel long-echo (TR 2,000 ms, TE 136 ms, 128-256 acquisitions) (1)H-MRS of the tumor, peritumoral brain tissue, and distant normal-appearing white matter before and several hours (median, 3 h; range, 1.2-3.7 h) after ingestion of choline with prescribed dose of 50 mg/kg (median actual dose, 52 mg/kg; range, 48-78 mg/kg). Investigations were done using 1.5 T clinical magnetic resonance imager. The volume of the rectangular (1)H-MRS voxel was either 3.4 or 8 cm(3). At the time of both spectroscopic examinations, similar voxels' positioning and size and technical parameters of (1)H-MRS were used. Surgery was done in 27 patients within 1 to 68 days thereafter. In all cases, more than 80% resection of the neoplasm was attained., Results: There were 12 low-grade gliomas and 15 high-grade gliomas. MIB-1 index varied from 0% to 51.7% (median, 13.8%). Statistical analysis did not disclose significant differences of any investigated metabolic parameter of the tumor, peritumoral brain tissue and distant normal-appearing white matter between two spectroscopic examinations., Conclusion: Single-voxel (1)H-MRS at 1.5 T could not detect significant changes of the metabolic characteristics of gliomas, peritumoral brain tissue, and distant normal-appearing white matter after oral administration of choline.

A combination of 5-aminolevulinic acid (5-ALA)-induced fluorescence and three-dimensional (3-D) magnetic resonance imaging (MRI) of a brain tumor has been incorporated into a robotic laser ablation neurosurgery system. 5-ALA is a non-fluorescent prodrug that leads to intracellular accumulation of fluorescent protoporphyrins IX (PpIX) in malignant glioma. The PpIX tends to accumulate in pathological lesions, and emits red fluorescence when excited by blue light. This fluorescence is illuminated with laser excitation, enables intra-operative identification of the position of a tumor and provides guidance for resection with laser photocoagulation. The information provided by the MRI is enhanced by the 5-ALA fluorescence data, and this enhanced information is integrated into a robotic laser ablation system. The accuracy of the fluorescent measurement of the tumor is improved using high-precision spectral analysis. The fluorescence assists in the detection of malignant brain tumors intraoperatively and improves their removal rate.

Rationale and Objectives: Gross-total surgery under intraoperative magnetic resonance imaging (MRI) is a promising method of glioma removal. The purpose of this article is intraoperative measurement of resected tumor volume in MRI-guided glioma surgery using semiautomatic image segmentation to unbiased resection rate control., Materials and Methods: A newly developed software program based on a fuzzy connectedness (FC) segmentation algorithm was used to achieve fast and semiautomatic tumor segmentation and tumor volume measurement. The program was validated by retrospective study of eight glioma cases and then applied to seven glioma cases. All clinical cases underwent actual MRI-guided surgery using 0.3-T open magnets., Results: The volume of the tumor before resection ranged from 10.1 to 206.7 mL. A comparison of the results of manual segmentation with those of the semiautomatic FC-based segmentation gave an average dice similarity coefficient of 0.80 and an average match of 76%. Volume measurement combined with a developed software program enabled quantitative monitoring of tumor removal, which was critical in the near-total resection of glioma in MRI-guided surgery., Conclusion: The FC-based tumor segmentation method can be used for intraoperative tumor segmentation and volume measurement in MRI-guided glioma surgery using 0.3-T open magnets. This method is useful for objective resection rate monitoring, which may ultimately minimize the amount of residual tumor in glioma surgery.

Although advanced preoperative imaging has been developed recent years, intraoperative imaging and monitoring are limited. We have developed an operating system to obtain objective and visible information for advanced neurosurgery. Intraoperative MRI and updated navigation are powerful tools to navigate surgeons to the residual lesions. This system has contributed to the improvement of the resection rate and the safety in the cases of gliomas and pituitary tumors.

Simple Summary: Predicting the isocitrate dehydrogenase (IDH) mutation status is difficult in preoperative non-enhanced astrocytic tumors. We aimed to differentiate IDH status using preoperative MRI and PET. We found that patients with IDH-mutant (mut) astrocytomas were significantly younger than those with IDH-wildtype (wt) glioblastomas. The tumor location, fractional anisotropy, and mean diffusivity on MRI were significantly related to the IDH mutation status. PET showed significantly higher uptakes for 11C-methionine, 11C-choline, and 18F-fluorodeoxyglucose in IDH-wt than in IDH-mut tumors. Together, these findings reflect the higher malignancy of IDH-wt than of IDH-mut tumors. Composite diagnosis using age, MRI, and PET findings resulted in high accuracy for predicting IDH status. Thus, approaches based on biological tumor behavior in early-stage gliomas are helpful for guiding preoperative treatment decisions. We aimed to differentiate the isocitrate dehydrogenase (IDH) status among non-enhanced astrocytic tumors using preoperative MRI and PET. We analyzed 82 patients with non-contrast-enhanced, diffuse, supratentorial astrocytic tumors (IDH mutant [IDH-mut], 55 patients; IDH-wildtype [IDH-wt], 27 patients) who underwent MRI and PET between May 2012 and December 2022. We calculated the fractional anisotropy (FA) and mean diffusivity (MD) values using diffusion tensor imaging. We evaluated the tumor/normal brain uptake (T/N) ratios using 11C-methionine, 11C-choline, and 18F-fluorodeoxyglucose PET; extracted the parameters with significant differences in distinguishing the IDH status; and verified their diagnostic accuracy. Patients with astrocytomas were significantly younger than those with glioblastomas. The following MRI findings were significant predictors of IDH-wt instead of IDH-mut: thalamus invasion, contralateral cerebral hemisphere invasion, location adjacent to the ventricular walls, higher FA value, and lower MD value. The T/N ratio for all tracers was significantly higher for IDH-wt than for IDH-mut. In a composite diagnosis based on nine parameters, including age, 84.4% of cases with 0–4 points were of IDH-mut; conversely, 100% of cases with 6–9 points were of IDH-wt. Composite diagnosis using all parameters, including MRI and PET findings with significant differences, may help guide treatment decisions for early-stage gliomas. [ABSTRACT FROM AUTHOR]

Purpose: We developed a navigation system that superimposes the fractional anisotropy (FA) color map of pre-operative diffusion tensor imaging (DTI) and intraoperative magnetic resonance imaging (MRI). The current study aimed to investigate the usefulness of this system for neurophysiological monitoring and examination under awake craniotomy during tumor removal. Method: A total of 10 glioma patients (4 patients with right-side tumors; 5 men and 5 women; average age, 34 years) were evaluated. Among them, the tumor was localized to the frontal lobe, insular cortex, and parietal lobe in 8, 1, and 1 patient, respectively. There were 3 patients who underwent surgery on general anesthesia, while 7 patients underwent awake craniotomy. The index of DTI anisotropy taken pre-operatively (magnetic field: 3 tesla, 6 motion probing gradient directions) was analyzed as a color map (FA color map) and concurrently co-registered in the intraoperative MRI within the navigation. In addition to localization of the bipolar coagulator and the cortical stimulator for brain mapping on intraoperative MRI, the pre-operative FA color map was also concurrently integrated and displayed on the navigation monitor. This white matter nerve functional information was confirmed directly by using neurological examination and referring to the electrophysiological monitoring. Results: Intraoperative MRI, integrated pre-operative FA color map, and microscopic surgical view were displayed on one screen in all 10 patients, and white matter fibers including the pyramidal tract were displayed as a reference in blue. Regarding motor function, motor-evoked potential was monitored as appropriate in all cases, and removal was possible while directly confirming motor symptoms under awake craniotomy. Furthermore, the white matter fibers including the superior longitudinal fasciculus were displayed in green. Importantly, it was useful not only to localize the resection site, but to identify language-related, eye movement-related, and motor fibers at the electrical stimulation site. All motor and/or language white matter tracts were identified and visualized with the co-registration and then with an acceptable post-operative neurological outcome. Conclusion: Co-registering an intraoperative MR images and a pre-operative FA color map is a practical and useful method to predict the localization of critical white matter nerve functions intraoperatively in glioma surgery. [ABSTRACT FROM AUTHOR]

Rationale and objectives: Gross-total surgery under intraoperative magnetic resonance imaging (MRI) is a promising method of glioma removal. The purpose of this article is intraoperative measurement of resected tumor volume in MRI-guided glioma surgery using semiautomatic image segmentation to unbiased resection rate control. Materials and methods: A newly developed software program based on a fuzzy connectedness (FC) segmentation algorithm was used to achieve fast and semiautomatic tumor segmentation and tumor volume measurement. The program was validated by retrospective study of eight glioma cases and then applied to seven glioma cases. All clinical cases underwent actual MRI-guided surgery using 0.3-T open magnets. Results: The volume of the tumor before resection ranged from 10.1 to 206.7 mL. A comparison of the results of manual segmentation with those of the semiautomatic FC-based segmentation gave an average dice similarity coefficient of 0.80 and an average match of 76%. Volume measurement combined with a developed software program enabled quantitative monitoring of tumor removal, which was critical in the near-total resection of glioma in MRI-guided surgery. Conclusion: The FC-based tumor segmentation method can be used for intraoperative tumor segmentation and volume measurement in MRI-guided glioma surgery using 0.3-T open magnets. This method is useful for objective resection rate monitoring, which may ultimately minimize the amount of residual tumor in glioma surgery. [Copyright &y& Elsevier]

Surgical management and strategies for the supplementary motor area (SMA) epilepsy are described. The following is our preoperative evaluations. The steps include functional magnetic resonance imaging (fMRI), interictal dipole tracing (DT), subdural electrodes mapping, measurements of movement-related cortical potential (MRCP), and the use of the intraoperative open MRI under conscious craniotomy. Six patients with SMA epilepsy underwent surgery after the mapping procedures and are now seizure-free. Combinations of preoperative (fMRI, subdural electrodes mapping) and intraoperative mapping allow exact localization and identification of the critical functional areas. Early postoperative deficits in motor and speech function were profound but patients recovered rapidly. It is concluded that the step of mapping procedures plays an important role in the management of SMA epilepsy surgery. [ABSTRACT FROM AUTHOR]