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Background: Gliomas have a heterogeneous nature, and identifying the most aggressive parts of the tumor and defining tumor borders are important for histomolecular diagnosis, surgical resection, and radiation therapy planning. This study evaluated [ 18 F]-FACBC PET for glioma tissue classification., Methods: Pre-surgical [ 18 F]-FACBC PET/MR images were used during surgery and image-localized biopsy sampling in patients with high- and low-grade glioma. TBR was compared to histomolecular results to determine optimal threshold values, sensitivity, specificity, and AUC values for the classification of tumor tissue. Additionally, PET volumes were determined in patients with glioblastoma based on the optimal threshold. [ 18 F]-FACBC PET volumes and diagnostic accuracy were compared to ce-T1 MRI. In total, 48 biopsies from 17 patients were analyzed., Results: [ 18 F]-FACBC had low uptake in non-glioblastoma tumors, but overall higher sensitivity and specificity for the classification of tumor tissue (0.63 and 0.57) than ce-T1 MRI (0.24 and 0.43). Additionally, [ 18 F]-FACBC TBR was an excellent classifier for IDH1-wildtype tumor tissue (AUC: 0.83, 95% CI: 0.71-0.96). In glioblastoma patients, PET tumor volumes were on average eight times larger than ce-T1 MRI volumes and included 87.5% of tumor-positive biopsies compared to 31.5% for ce-T1 MRI., Conclusion: The addition of [ 18 F]-FACBC PET to conventional MRI could improve tumor classification and volume delineation.

The STRAT-PARK initiative aims to provide a platform for stratifying Parkinson's disease (PD) into biological subtypes, using a bottom-up, multidisciplinary biomarker-based and data-driven approach. PD is a heterogeneous entity, exhibiting high interindividual clinicopathological variability. This diversity suggests that PD may encompass multiple distinct biological entities, each driven by different molecular mechanisms. Molecular stratification and identification of disease subtypes is therefore a key priority for understanding and treating PD. STRAT-PARK is a multi-center longitudinal cohort aiming to recruit a total of 2000 individuals with PD and neurologically healthy controls from Norway and Canada, for the purpose of identifying molecular disease subtypes. Clinical assessment is performed annually, whereas biosampling, imaging, and digital and neurophysiological phenotyping occur every second year. The unique feature of STRAT-PARK is the diversity of collected biological material, including muscle biopsies and platelets, tissues particularly useful for mitochondrial biomarker research. Recruitment rate is ∼150 participants per year. By March 2023, 252 participants were included, comprising 204 cases and 48 controls. STRAT-PARK is a powerful stratification initiative anticipated to become a global research resource, contributing to personalized care in PD., Competing Interests: Declaration of Competing Interest none, (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: This PET/MRI study compared contrast-enhanced MRI, 18 F-FACBC-, and 18 F-FDG-PET in the detection of primary central nervous system lymphomas (PCNSL) in patients before and after high-dose methotrexate chemotherapy. Three immunocompetent PCNSL patients with diffuse large B-cell lymphoma received dynamic 18 F-FACBC- and 18 F-FDG-PET/MRI at baseline and response assessment. Lesion detection was defined by clinical evaluation of contrast enhanced T1 MRI (ce-MRI) and visual PET tracer uptake. SUVs and tumor-to-background ratios (TBRs) (for 18 F-FACBC and 18 F-FDG) and time-activity curves (for 18 F-FACBC) were assessed., Results: At baseline, seven ce-MRI detected lesions were also detected with 18 F-FACBC with high SUVs and TBRs (SUV max :mean, 4.73, TBR max : mean, 9.32, SUV peak : mean, 3.21, TBR peak :mean: 6.30). High TBR values of 18 F-FACBC detected lesions were attributed to low SUV background . Baseline 18 F-FDG detected six lesions with high SUVs (SUV max : mean, 13.88). In response scans, two lesions were detected with ce-MRI, while only one was detected with 18 F-FACBC. The lesion not detected with 18 F-FACBC was a small atypical MRI detected lesion, which may indicate no residual disease, as this patient was still in complete remission 12 months after initial diagnosis. No lesions were detected with 18 F-FDG in the response scans., Conclusions: 18 F-FACBC provided high tumor contrast, outperforming 18 F-FDG in lesion detection at both baseline and in response assessment. 18 F-FACBC may be a useful supplement to ce-MRI in PCNSL detection and response assessment, but further studies are required to validate these findings. Trial registration ClinicalTrials.gov. Registered 15th of June 2017 (Identifier: NCT03188354, https://clinicaltrials.gov/study/NCT03188354 )., (© 2024. The Author(s).)

Purpose: The primary aim was to evaluate whether anti-3-[ 18 F]FACBC PET combined with conventional MRI correlated better with histomolecular diagnosis (reference standard) than MRI alone in glioma diagnostics. The ability of anti-3-[ 18 F]FACBC to differentiate between molecular and histopathological entities in gliomas was also evaluated., Methods: In this prospective study, patients with suspected primary or recurrent gliomas were recruited from two sites in Norway and examined with PET/MRI prior to surgery. Anti-3-[ 18 F]FACBC uptake (TBR peak ) was compared to histomolecular features in 36 patients. PET results were then added to clinical MRI readings (performed by two neuroradiologists, blinded for histomolecular results and PET data) to assess the predicted tumor characteristics with and without PET., Results: Histomolecular analyses revealed two CNS WHO grade 1, nine grade 2, eight grade 3, and 17 grade 4 gliomas. All tumors were visible on MRI FLAIR. The sensitivity of contrast-enhanced MRI and anti-3-[ 18 F]FACBC PET was 61% (95%CI [45, 77]) and 72% (95%CI [58, 87]), respectively, in the detection of gliomas. Median TBR peak was 7.1 (range: 1.4-19.2) for PET positive tumors. All CNS WHO grade 1 pilocytic astrocytomas/gangliogliomas, grade 3 oligodendrogliomas, and grade 4 glioblastomas/astrocytomas were PET positive, while 25% of grade 2-3 astrocytomas and 56% of grade 2-3 oligodendrogliomas were PET positive. Generally, TBR peak increased with malignancy grade for diffuse gliomas. A significant difference in PET uptake between CNS WHO grade 2 and 4 gliomas (p < 0.001) and between grade 3 and 4 gliomas (p = 0.002) was observed. Diffuse IDH wildtype gliomas had significantly higher TBR peak compared to IDH1/2 mutated gliomas (p < 0.001). Adding anti-3-[ 18 F]FACBC PET to MRI improved the accuracy of predicted glioma grades, types, and IDH status, and yielded 13.9 and 16.7 percentage point improvement in the overall diagnoses for both readers, respectively., Conclusion: Anti-3-[ 18 F]FACBC PET demonstrated high uptake in the majority of gliomas, especially in IDH wildtype gliomas, and improved the accuracy of preoperatively predicted glioma diagnoses., Clinical Trial Registration: ClinicalTrials.gov ID: NCT04111588, URL: https://clinicaltrials.gov/study/NCT04111588., (© 2023. The Author(s).)

Purpose: The study aims to evaluate whether combined 18 F-FACBC PET/MRI could provide additional diagnostic information compared with MRI alone in brain metastases., Patients and Methods: Eighteen patients with newly diagnosed or suspected recurrence of brain metastases received dynamic 18 F-FACBC PET/MRI. Lesion detection was evaluated on PET and MRI scans in 2 groups depending on prior stereotactic radiosurgery (SRS group) or not (no-SRS group). SUVs, time-activity curves, and volumetric analyses of the lesions were performed., Results: In the no-SRS group, 29/29 brain lesions were defined as "MRI positive." With PET, 19/29 lesions were detected and had high tumor-to-background ratios (TBRs) (D max MR , ≥7 mm; SUV max , 1.2-8.4; TBR, 3.9-25.9), whereas 10/29 lesions were undetected (D max MR , ≤8 mm; SUV max , 0.3-1.2; TBR, 1.0-2.7). In the SRS group, 4/6 lesions were defined as "MRI positive," whereas 2/6 lesions were defined as "MRI negative" indicative of radiation necrosis. All 6 lesions were detected with PET (D max MR , ≥15 mm; SUV max , 1.4-4.2; TBR, 3.6-12.6). PET volumes correlated and were comparable in size with contrast-enhanced MRI volumes but were only partially congruent (mean DSC, 0.66). All time-activity curves had an early peak, followed by a plateau or a decreasing slope., Conclusions: 18 F-FACBC PET demonstrated uptake in brain metastases from cancer of different origins (lung, gastrointestinal tract, breast, thyroid, and malignant melanoma). However, 18 F-FACBC PET/MRI did not improve detection of brain metastases compared with MRI but might detect tumor tissue beyond contrast enhancement on MRI. 18 F-FACBC PET should be further evaluated in recurrent brain metastases., Competing Interests: Conflicts of interest and sources of funding: The authors declare that they have no conflicts of interest. The work was supported by Trond Mohn Foundation., (Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc.)

Purpose: To assess the ability of 7 T MRI to detect hippocampal DWI lesions in the acute phase of TGA compared to 1.5 T/3 T MRI., Methods: Patients with a clinical diagnosis consistent with TGA and a 1.5/3 T MRI underwent an additional 7 T MRI when the 7 T system was available for clinical use, thus serving as their own controls., Results: Thirteen TGA patients with a median age of 68.5 years (range 46-77 years) were included and imaged at 1.5/3 T (median 17 h after onset of symptoms, range 3-23 h) and 7 T (median 23 h after onset, range 15-46 h). The 7 T MRIs were performed a median of 15 h after the 1.5/3 T MRIs (range 1-28 h). At 1.5/3 T, six patients (46%) were found to have at least one hippocampal DWI-lesions supporting the TGA diagnosis, which increased to 11 patients (85%) when examined at 7 T (p = 0.03). At 1.5/3 T, nine hippocampal DWI lesions were detected, which increased to 19 at 7 T, giving an increased detection rate of 111% (p = 0.002). Both neuroradiologists found the hippocampal DWI lesions at 7 T to have higher conspicuity and be easier to categorize as true findings compared to 1.5/3 T., Conclusion: Seven-Tesla MRI showed both a statistically significant increase in the total number of detected hippocampal DWI lesions and the proportion of patients with at least one hippocampal DWI lesion supporting the TGA diagnosis compared to 1.5/3 T. Clinical use of 7 T will increase the number of patients having their TGA diagnosis supported by MRI, which can be especially useful in patients with negative 1.5/3 T MRI and low clinical certainty., (© 2022. The Author(s).)

Background and Purpose: Imaging biomarkers derived from different brainstem structures are suggested to differentiate among parkinsonian disorders, but clinical implementation requires normative data. The main objective was to establish high-quality, sex-specific data for relevant brainstem structures derived from MR imaging in healthy subjects from the general population in their sixth and seventh decades of life., Materials and Methods: 3D T1WI acquired on the same 1.5T scanner of 996 individuals (527 women) between 50 and 66 years of age from a prospective population study was used. The area of the midbrain and pons and the widths of the middle cerebellar peduncles and superior cerebellar peduncles were measured, from which the midbrain-to-pons ratio and Magnetic Resonance Parkinsonism Index [MRPI = (Pons Area / Midbrain Area) × (Middle Cerebellar Peduncles / Superior Cerebellar Peduncles)] were calculated. Sex differences in brainstem measures and correlations to age, height, weight, and body mass index were investigated., Results: Inter- and intrareliability for measuring the different brainstem structures showed good-to-excellent reliability (intraclass correlation coefficient = 0.785-0.988). There were significant sex differences for the pons area, width of the middle cerebellar peduncles and superior cerebellar peduncles, midbrain-to-pons ratio, and MRPI (all, P  <  .001; Cohen D = 0.44-0.98), but not for the midbrain area ( P  = .985). There were significant very weak-to-weak correlations between several of the brainstem measures and age, height, weight, and body mass index in both sexes. However, no systematic difference in distribution caused by these variables was found, and because age had the highest and most consistent correlations, age-/sex-specific percentiles for the brainstem measures were created., Conclusions: We present high-quality, sex-specific data and age-/sex-specific percentiles for the mentioned brainstem measures. These normative data can be implemented in the neuroradiologic work-up of patients with suspected brainstem atrophy to avoid the risk of misdiagnosis., (© 2022 by American Journal of Neuroradiology.)

Background: Prevalence, radiological characteristics, and risk factors for peritumoral infarctions after glioma surgery are not much studied. In this study, we assessed shape, volume, and prevalence of peritumoral infarctions and investigated possible associated factors., Methods: In a prospective single-center cohort study, we included all adult patients operated for diffuse gliomas from January 2007 to December 2018. Postoperative infarctions were segmented using early postoperative MRI images, and volume, shape, and location of postoperative infarctions were assessed. Heatmaps of the distribution of tumors and infarctions were created., Results: MRIs from 238 (44%) of 539 operations showed restricted diffusion in relation to the operation cavity, interpreted as postoperative infarctions. Of these, 86 (36%) were rim-shaped, 103 (43%) were sector-shaped, 40 (17%) were a combination of rim- and sector-shaped, and six (3%) were remote infarctions. Median infarction volume was 1.7 cm 3 (IQR 0.7-4.3, range 0.1-67.1). Infarctions were more common if the tumor was in the temporal lobe, and the map shows more infarctions in the periventricular watershed areas. Sector-shaped infarctions were more often seen in patients with known cerebrovascular disease (47.6% vs. 25.5%, p = 0.024). There was a positive correlation between infarction volume and tumor volume (r = 0.267, p < 0.001) and infarction volume and perioperative bleeding (r = 0.176, p = 0.014). Moreover, there was a significant positive association between age and larger infarction volumes (r = 0.193, p = 0.003). Infarction rates and infarction volumes varied across individual surgeons, p = 0.037 (range 32-72%) and p = 0.026., Conclusions: In the present study, peritumoral infarctions occurred in 44% after diffuse glioma operations. Infarctions were more common in patients operated for tumors in the temporal lobe but were not more common following recurrent surgeries. Sector-shaped infarctions were more common in patients with known cerebrovascular disease. Increasing age, larger tumors, and more perioperative bleeding were factors associated with infarction volumes. The risk of infarctions and infarction volumes may also be surgeon-dependent., (© 2021. The Author(s).)

Purpose: The main aim of this study was to provide normative data for pituitary height and volume in persons between 50 and 66 years in the general population. The secondary aim was to establish a convenient surrogate marker of pituitary size for use in routine radiological practice., Methods: From a geographically defined prospective healthy study, 1006 participants between 50 and 66 years had a brain MRI, of which 988 (519 women) were included in this study. We measured the mid-sagittal height, max-sagittal height and total volume of the anterior pituitary lobe based on T1-weighted 3D MRI images., Results: Both the mean mid-sagittal and max-sagittal pituitary height were significantly larger in women compared to men, with 4.9 ± 1.7 mm versus 4.4 ± 1.4 mm (p < .001) for the mean mid-sagittal height and 6.8 ± 1.2 mm versus 6.1 ± 1.1 mm (p < 0.001) for the mean max-sagittal height. The mean anterior pituitary lobe volume was also significantly larger in women than in men (494 ± 138 mm 3 vs. 405 ± 118 mm 3 ) (p < 0.001). There were no significant differences in these pituitary sagittal heights nor volume in either sex between the age groups 50-54, 55-59 and 60-66 years. The 95th percentile for mid-sagittal height, max-sagittal height and pituitary volume was 7.7 mm, 8.6 mm and 851 mm 3 for women and 6.6 mm, 7.8 mm and 610 mm 3 for men., Conclusion: This study show that women have a larger pituitary gland than men in the age group between 50 and 66 years and provides normative data for pituitary size estimates which can be used for clinical diagnostic purposes as well as future research., (© 2021. The Author(s).)

Purpose: Previous studies on the effect of tumor location on overall survival in glioblastoma have found conflicting results. Based on statistical maps, we sought to explore the effect of tumor location on overall survival in a population-based cohort of patients with glioblastoma and IDH wild-type astrocytoma WHO grade II-III with radiological necrosis., Methods: Patients were divided into three groups based on overall survival: < 6 months, 6-24 months, and > 24 months. Statistical maps exploring differences in tumor location between these three groups were calculated from pre-treatment magnetic resonance imaging scans. Based on the results, multivariable Cox regression analyses were performed to explore the possible independent effect of centrally located tumors compared to known prognostic factors by use of distance from center of the third ventricle to contrast-enhancing tumor border in centimeters as a continuous variable., Results: A total of 215 patients were included in the statistical maps. Central tumor location (corpus callosum, basal ganglia) was associated with overall survival < 6 months. There was also a reduced overall survival in patients with tumors in the left temporal lobe pole. Tumors in the dorsomedial right temporal lobe and the white matter region involving the left anterior paracentral gyrus/dorsal supplementary motor area/medial precentral gyrus were associated with overall survival > 24 months. Increased distance from center of the third ventricle to contrast-enhancing tumor border was a positive prognostic factor for survival in elderly patients, but less so in younger patients., Conclusions: Central tumor location was associated with worse prognosis. Distance from center of the third ventricle to contrast-enhancing tumor border may be a pragmatic prognostic factor in elderly patients.

Background: Patients with metastatic cancer to the brain have a poor prognosis. In clinical practice, MRI is used to delineate, diagnose and plan treatment of brain metastases. However, MRI alone is limited in detecting micro-metastases, delineating lesions and discriminating progression from pseudo-progression. Combined PET/MRI utilises superior soft tissue images from MRI and metabolic data from PET to evaluate tumour structure and function. The amino acid PET tracer 18 F-FACBC has shown promising results in discriminating high- and low-grade gliomas, but there are currently no reports on its use on brain metastases. This is the first study to evaluate the use of 18 F-FACBC on brain metastases., Case Presentation: A middle-aged female patient with brain metastases was evaluated using hybrid PET/MRI with 18 F-FACBC before and after stereotactic radiotherapy, and at suspicion of recurrence. Static/dynamic PET and contrast-enhanced T1 MRI data were acquired and analysed. This case report includes the analysis of four 18 F-FACBC PET/MRI examinations, investigating their utility in evaluating functional and structural metastasis properties., Conclusion: Analysis showed high tumour-to-background ratios in brain metastases compared to other amino acid PET tracers, including high uptake in a very small cerebellar metastasis, suggesting that 18 F-FACBC PET can provide early detection of otherwise overlooked metastases. Further studies to determine a threshold for 18 F-FACBC brain tumour boundaries and explore its utility in clinical practice should be performed.

Background: The otic ganglion (OG) provides parasympathetic innervation to the cerebral circulation and cranial structures and may be involved in the pathophysiology of trigeminal autonomic headaches. This structure has never been targeted in any headache disorder., Objective: To investigate the safety of injecting onabotulinumtoxin A (BTA) toward the OG in 10 patients with intractable chronic cluster headache and to collect efficacy data., Methods: A total of 10 patients with chronic cluster headache were enrolled in this open-label, multi-dose pilot safety study. All patients were recruited and treated on an out-patient basis at St Olav's University Hospital (Norway). In 5 patients each, the OG was the injection target with 12.5 IU of BTA or 25 IU, respectively. The primary outcome measure was adverse events (AEs) and the main secondary outcome was the number of attacks per week measured at baseline and in the second month following injection., Results: For the primary endpoint, we analyzed data for all 10 patients. There were a total of 17 AEs in 6 of the 10 patients. All AEs were considered mild and disappeared by the end of follow-up. The median number of attacks per week at baseline was 17.0 [7.8 to 25.8] vs 14.0 [7.3 to 20.0] in the second month following injection; difference: 3 (95%CI: -0.3 to 7.9), P = .063., Conclusions: Injection with BTA toward the OG appears to be safe. We did not find a statistically significant reduction in the number of attacks per week at month 2 after injection compared to the baseline. This study suggests that the OG is not an important target for the treatment of chronic cluster headache. A future study employing more precise targeting of the OG may be indicated., (© 2020 The Authors. Headache: The Journal of Head and Face Pain published by Wiley Periodicals LLC on behalf of American Headache Society.)

O6-methylguanine DNA methyltransferase (MGMT) promoter methylation is an important favorable predictive marker in patients with glioblastoma (GBM). We hypothesized that MGMT status could be a surrogate marker of pretreatment tumor biology observed as histopathological and radiological features. Apart from some radiological studies aiming to noninvasively predict the MGMT status, few studies have investigated relationships between MGMT status and phenotypical tumor biology. We have therefore aimed to investigate such relationships in 85 isocitrate dehydrogenase (IDH) wild-type GBMs. MGMT status was determined by methylation-specific PCR and was assessed for associations with 22 histopathological features, immunohistochemical proliferative index and microvessel density measurements, conventional magnetic resonance imaging characteristics, preoperative speed of tumor growth, and overall survival. None of the investigated histological or radiological features were significantly associated with MGMT status. Methylated MGMT status was a significant independent predictor of improved overall survival. In conclusion, our results suggest that MGMT status is not related to the pretreatment phenotypical biology in IDH wild-type GBMs. Furthermore, our findings suggest the survival benefit of MGMT methylated GBMs is not due to an inherently less aggressive tumor biology, and that conventional magnetic resonance imaging features cannot be used to noninvasively predict the MGMT status., (© 2020 American Association of Neuropathologists, Inc.)

Introduction: According to the stem cell theory, two neurogenic niches in the adult human brain may harbor cells that initiate the formation of gliomas: The larger subventricular zone (SVZ) and the subgranular zone (SGZ) in the hippocampus. We wanted to explore whether defining molecular markers in low-grade gliomas (LGG; WHO grade II) are related to distance to the neurogenic niches., Methods: Patients treated at two Norwegian university hospitals with population-based referral were included. Eligible patients had histopathological verified supratentorial low-grade glioma. IDH mutational status and 1p19q co-deletion status was retrospectively assessed. 159 patients were included, and semi-automatic tumor segmentation was done from pre-treatment T2-weighted (T2W) or Fluid-Attenuated Inversion Recovery (FLAIR) images. 3D maps showing the anatomical distribution of the tumors were then created for each of the three molecular subtypes (IDH mutated/1p19q co-deleted, IDH mutated and IDH wild-type). Both distance from tumor center and tumor border to the neurogenic niches were recorded., Results: In this population-based cohort of previously untreated low-grade gliomas, we found that low-grade gliomas are more often found closer to the SVZ than the SGZ, but IDH wild-type tumors are more often found near SGZ., Conclusion: Our study suggests that the stem cell origin of IDH wild-type and IDH mutated low-grade gliomas may be different.

Rationale and Objectives: Team-based learning (TBL) is a student-centred, teacher-directed instructional method that promotes active learning. The application phase of TBL stimulates group discussion and critical thinking, which could be useful for learning radiology. We designed and evaluated two modified TBL-sessions on computed tomography and magnetic resonance imaging diagnostics in neuroradiology. Our aim was to examine what effects engaging students in in-class team application tasks had on student learning., Materials and Methods: A cross-over study was conducted, including 105 third-year medical students using two modified TBL sessions as the active learning intervention compared with two traditional lectures as a control. Student learning was assessed by results on the neuroradiology part of the end-of-year written examination. Student engagement and perceptions were assessed using the Student Self-Report of Engagement Measure and an additional four Likert-type items., Results: There were no statistically significant differences in student scores on the examination. Students reported high levels of engagement, and reported being more satisfied overall with the TBL sessions than traditional lectures. Students rated the TBL sessions higher than lectures on ability to make difficult material comprehensible, ability to engage students and to give them feedback., Conclusion: The modified TBL sessions halved in-class teaching time and by omitting the readiness assurance tests, there was more in-class time to focus on problem-solving of real clinical cases. Moreover, shorter sessions may ease implementation of TBL in the curriculum and allow for more frequent sessions. Students were more satisfied with eTBL than lectures, and reported high levels of engagement., (Copyright © 2019 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.)

Background: Detection of progression is clinically important for the management of glioblastoma. We sought to assess the accuracy of clinical radiological reporting and measured bidimensional products to identify radiological glioblastoma progression. The two were compared to volumetric segmentation., Methods: In this retrospective study, we included 106 patients with histopathologically verified glioblastomas and two separate MRI scans obtained before surgery. Bidimensional products based on measurements on the axial slice with the largest tumor area were calculated, and growth estimations from the clinical radiological reports were retrieved. The two growth estimations were compared to manual volumetric segmentations. Inter-observer agreement using the bidimensional product was assessed using Kappa-statistics and by calculating the difference between two neuroradiologist in percentage change of the bidimensional product for each tumor., Results: Clinical radiological reports and bidimensional products showed fairly equal accuracy when compared to volumetric segmentation with an accuracy of 67% and 66-68%, respectively. There was a difference in median volume increase of 6.9 mL (2.4 vs 9.3 mL, p < 0.001) between tumors evaluated as stable and progressed based on the clinical radiological reports. This difference was 8.1 mL (2.0 vs 10.1 ml, p < 0.001) when using the bidimensional products. The bidimensional product reached a moderate inter-observer agreement with a Kappa value of 0.689. For 32% of the tumors, the two neuroradiologists calculated a difference of more than 25% using bidimensional products., Conclusions: Clinical radiological reporting and the bidimensional product exhibit similar accuracy. The bidimensional product has moderate inter-observer agreement and is prone to underestimating tumor progression, as an average glioblastoma had to grow 10 mL in order to be classified as progressed. These findings underline the assumption that one should try to move towards volumetric assessment of glioblastoma growth in the future.

Background: Positron emission tomography/magnetic resonance imaging (PET/MRI) is a promising diagnostic imaging tool for the diagnosis of dementia, as PET can add complementary information to the routine imaging examination with MRI. The purpose of this study was to evaluate the influence of MRI-based attenuation correction (MRAC) on diagnostic assessment of dementia with [ 18 F]FDG PET. Quantitative differences in both [ 18 F]FDG uptake and z-scores were calculated for three clinically available (DixonNoBone, DixonBone, UTE) and two research MRAC methods (UCL, DeepUTE) compared to CT-based AC (CTAC). Furthermore, diagnoses based on visual evaluations were made by three nuclear medicine physicians and one neuroradiologist (PET CT , PET DeepUTE , PET DixonBone , PET UTE , PET CT + MRI, PET DixonBone + MRI). In addition, pons and cerebellum were compared as reference regions for normalization., Results: The mean absolute difference in z-scores were smallest between MRAC and CTAC with cerebellum as reference region: 0.15 ± 0.11 σ (DeepUTE), 0.15 ± 0.12 σ (UCL), 0.23 ± 0.20 σ (DixonBone), 0.32 ± 0.28 σ (DixonNoBone), and 0.54 ± 0.40 σ (UTE). In the visual evaluation, the diagnoses agreed with PET CT in 74% (PET DeepUTE ), 67% (PET DixonBone ), and 70% (PET UTE ) of the patients, while PET CT + MRI agreed with PET DixonBone + MRI in 89% of the patients., Conclusion: The MRAC research methods performed close to that of CTAC in the quantitative evaluation of [ 18 F]FDG uptake and z-scores. Among the clinically implemented MRAC methods, Dixon Bone should be preferred for diagnostic assessment of dementia with [ 18 F]FDG PET/MRI. However, as artifacts occur in Dixon Bone attenuation maps, they must be visually inspected to assure proper quantification.

Purpose: This pilot study aimed to evaluate the amino acid tracer F-FACBC with simultaneous PET/MRI in diagnostic assessment and neurosurgery of gliomas., Materials and Methods: Eleven patients with suspected primary or recurrent low- or high-grade glioma received an F-FACBC PET/MRI examination before surgery. PET and MRI were used for diagnostic assessment, and for guiding tumor resection and histopathological tissue sampling. PET uptake, tumor-to-background ratios (TBRs), time-activity curves, as well as PET and MRI tumor volumes were evaluated. The sensitivities of lesion detection and to detect glioma tissue were calculated for PET, MRI, and combined PET/MRI with histopathology (biopsies for final diagnosis and additional image-localized biopsies) as reference., Results: Overall sensitivity for lesion detection was 54.5% (95% confidence interval [CI], 23.4-83.3) for PET, 45.5% (95% CI, 16.7-76.6) for contrast-enhanced MRI (MRICE), and 100% (95% CI, 71.5-100.0) for combined PET/MRI, with a significant difference between MRICE and combined PET/MRI (P = 0.031). TBRs increased with tumor grade (P = 0.004) and were stable from 10 minutes post injection. PET tumor volumes enclosed most of the MRICE volumes (>98%) and were generally larger (1.5-2.8 times) than the MRICE volumes. Based on image-localized biopsies, combined PET/MRI demonstrated higher concurrence with malignant findings at histopathology (89.5%) than MRICE (26.3%)., Conclusions: Low- versus high-grade glioma differentiation may be possible with F-FACBC using TBR. F-FACBC PET/MRI outperformed MRICE in lesion detection and in detection of glioma tissue. More research is required to evaluate F-FACBC properties, especially in grade II and III tumors, and for different subtypes of gliomas.

Objective: Extent of resection (EOR) and residual tumor volume are linked to prognosis in low-grade glioma (LGG) and there are various methods for facilitating safe maximal resection in such patients. In this prospective study the authors assess radiological and clinical results in consecutive patients with LGG treated with 3D ultrasound (US)-guided resection under general anesthesia., Methods: Consecutive LGGs undergoing primary surgery guided with 3D US between 2008 and 2015 were included. All LGGs were classified according to the WHO 2016 classification system. Pre- and postoperative volumetric assessments were performed, and volumetric results were linked to overall and malignant-free survival. Pre- and postoperative health-related quality of life (HRQoL) was evaluated., Results: Forty-seven consecutive patients were included. Twenty LGGs (43%) were isocitrate dehydrogenase (IDH)-mutated, 7 (14%) were IDH wild-type, 19 (40%) had both IDH mutation and 1p/19q codeletion, and 1 had IDH mutation and inconclusive 1p/19q status. Median resection grade was 93.4%, with gross-total resection achieved in 14 patients (30%). An additional 24 patients (51%) had small tumor remnants < 10 ml. A more conspicuous tumor border (p = 0.02) and lower University of California San Francisco prognostic score (p = 0.01) were associated with less remnant tumor tissue, and overall survival was significantly better with remnants < 10 ml (p = 0.03). HRQoL was maintained or improved in 86% of patients at 1 month. In both cases with severe permanent deficits, relevant ischemia was present on diffusion-weighted postoperative MRI., Conclusions: Three-dimensional US-guided LGG resections under general anesthesia are safe and HRQoL is preserved in most patients. Effectiveness in terms of EOR appears to be consistent with published studies using other advanced neurosurgical tools. Avoiding intraoperative vascular injury is a key factor for achieving good functional outcome.

Background: The preoperative growth of human glioblastomas (GBMs) has been shown to vary among patients. In animal studies, angiogenesis has been linked to hypoxia and faster growth of GBM, however, its relation to the growth of human GBMs is sparsely studied. We have therefore aimed to look for associations between radiological speed of growth and microvessel density (MVD) counts of the endothelial markers vWF (Factor VIII related antigen) and CD105 (endoglin)., Methods: Preoperative growth was estimated from segmented tumor volumes of two preoperative T1-weighted postcontrast magnetic resonance imaging scans taken ≥14 days apart in patients with newly diagnosed GBMs. A Gompertzian growth curve was computed from the volume data and separated the patients into two groups of either faster or slower tumor growth than expected. MVD counts of the immunohistochemical markers von Willebrand factor (vWF) (a pan-endothelial marker) and CD105 (a marker of proliferating endothelial cells) were assessed for associations with fast-growing tumors using Mann-Whitney U tests and a multivariable binary logistic regression analysis., Results: We found that only CD105-MVD was significantly associated with faster growth in a univariable analysis (p = 0.049). However, CD105-MVD was no longer significant when corrected for the presence of thromboses and high cellular density in a multivariable model, where the latter features were significant independent predictors of faster growth with respective odds ratios 4.2 (95% confidence interval, 1.2, 14.3), p = 0.021 and 2.6 (95% confidence interval, 1.0, 6.5), p = 0.048., Conclusions: MVDs of neither endothelial marker were independently associated with faster growth, suggesting angiogenesis-independent processes contribute to faster glioblastoma growth.

Background: Image guidance based on magnetic resonance imaging (MRI) and/or ultrasound (US) is widely used to aid decision making in glioma surgery, but tumor delineation based on these 2 modalities does not always correspond., Objective: To analyze volumes of diffuse low-grade gliomas (LGGs) based on preoperative 3-D FLAIR MRIs compared to intraoperative 3-D US image recordings to quantitatively assess potential discrepancies between the 2 imaging modalities., Methods: Twenty-three patients with supratentorial WHO grade II gliomas undergoing primary surgery guided by neuronavigation based on preoperative FLAIR MRI and navigated 3-D US were included. Manual volume segmentation was performed twice in 3-D Slicer version 4.0.0 to assess intrarater variabilities and compare modalities with regard to tumor volume. Factors possibly related to correspondence between MRI and US were also explored., Results: In 20 out of 23 patients (87%), the LGG tumor volume segmented from intraoperative US data was smaller than the tumor volume segmented from the preoperative 3-D FLAIR MRI. The median difference between MRI and US volumes was 7.4 mL (range: -4.9-58.7 mL, P < .001) with US LGG volumes corresponding to a median of 74% (range: 42%-183%) of the MRI LGG volumes. However, there was considerable intraobserver variability for US volumes. The correspondence between MRI and US data was higher for astrocytomas (92%)., Conclusion: The tumor volumes of LGGs segmented from intraoperative US images were most often smaller than the tumor volumes segmented from preoperative MRIs. There was a much better match between the 2 modalities in astrocytomas.

Objectives: Observational data on the natural course of tumor growth in humans is sparse, and mathematical models of tumor growth are often needed to answer questions related to growth. In this study, a theoretical model of glioblastoma growth was used to investigate two questions often asked by patients and clinicians. First, when did the tumor start growing? Second, how much survival time can be gained from various extents of surgical resection (EOR)?., Patients and Methods: A gompertzian growth curve was fitted from observational data of pre-treatment growth from 106 glioblastoma patients based on repeated volume segmentations. The curve was used to find the theoretical time since tumor initiation. In addition, as a proxy for the potential survival gain from surgery, the number of days until re-growth would reach the preoperative tumor volume were calculated for different extents of resection., Results: The estimated age of the glioblastomas at diagnosis was median 330 days, but ranging from 156 days to 776 days, depending on the tumor volume at diagnosis. The median survival gains from 50%, 75%, 90%, 95% and 99% EOR were, 1.4, 2.5, 3.6, 4.3, and 5.6 months, respectively. However, survival benefit from surgery also depends on lesion volume. In theory, 100 days may be gained from 95% EOR in a 10 mL lesion or a 50% EOR in a 90 ml lesion., Conclusion: In conclusion, we postulate that glioblastoma might originate median 330 days before the diagnosis, assuming the same growth pattern and biology from day one. The theoretical survival benefit of glioblastoma resection is much higher with higher EORs, suggesting that the last milliliters of resection matter the most. Our data also suggest that gain from resection is higher in larger lesions, suggesting that lesion volume may be taken into account in clinical decision-making., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Generating MR-derived growth pattern models for glioblastoma multiforme (GBM) has been an attractive approach in neuro-oncology, suggesting a distinct pattern of lesion spread with a tendency in growing along the white matter (WM) fibre direction for the invasive component. However, the direction of growth is not much studied in vivo. In this study, we sought to study the dominant directions of tumour expansion/shrinkage pre-treatment. We examined fifty-six GBMs at two time-points: at radiological diagnosis and as part of the pre-operative planning, both with contrast-enhanced T1-weighted MRIs. The tumour volumes were semi-automatically segmented. A non-linear registration resulting in a deformation field characterizing the changes between the two time points was used together with the segmented tumours to determine the dominant directions of tumour change. To compute the degree of alignment between tumour growth vectors and WM fibres, an angle map was calculated. Our results demonstrate that tumours tend to grow predominantly along the WM, as evidenced by the dominant vector population with the maximum alignments. Our findings represent a step forward in investigating the hypothesis that tumour cells tend to migrate preferentially along the WM.

Objectives: Molecular markers provide valuable information about treatment response and prognosis in patients with low-grade gliomas (LGG). In order to make this important information available prior to surgery the aim of this study was to explore if molecular status in LGG can be discriminated by preoperative magnetic resonance imaging (MRI)., Patients and Methods: All patients with histopathologically confirmed LGG with available molecular status who had undergone a preoperative standard clinical MRI protocol using a 3T Siemens Skyra scanner during 2008-2015 were retrospectively identified. Based on Haralick texture parameters and the segmented LGG FLAIR volume we explored if it was possible to predict molecular status., Results: In total 25 patients (nine women, average age 44) fulfilled the inclusion parameters. The textural parameter homogeneity could discriminate between LGG patients with IDH mutation (0.12, IQR 0.10-0.15) and IDH wild type (0.07, IQR 0.06-0.09, p=0.005). None of the other four analyzed texture parameters (energy, entropy, correlation and inertia) were associated with molecular status. Using ROC curves, the area under curve for predicting IDH mutation was 0.905 for homogeneity, 0.840 for tumor volume and 0.940 for the combined parameters of tumor volume and homogeneity. We could not predict molecular status using the four other chosen texture parameters (energy, entropy, correlation and inertia). Further, we could not separate LGG with IDH mutation with or without 1p19q codeletion., Conclusions: In this preliminary study using Haralick texture parameters based on preoperative clinical FLAIR sequence, the homogeneity parameter could separate IDH mutated LGG from IDH wild type LGG. Combined with tumor volume, these diagnostic properties seem promising., (Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Rapid growth is a well-known property of glioblastoma (GBM); however, growth rates vary among patients. Mechanisms behind such variation have not been widely studied in human patients. We sought to investigate relationships between histopathologic features and tumor growth estimated from pretreatment magnetic resonance imaging scans., Methods: In 106 patients with GBM, 2 preoperative T1-weighted magnetic resonance imaging scans obtained at least 14 days apart were segmented to assess tumor growth. A fitted Gompertzian growth curve based on the segmented volumes divided the tumors into 2 groups: faster and slower growth than expected based on the initial tumor volume. Histopathologic features were investigated for associations with these groups, using univariable and multivariable logistic regression analyses., Results: The presence of high cellular density and thromboses was significantly associated with radiologic growth in the multivariable analysis (P = 0.018 and 0.019, respectively), with respective odds ratios of 3.0 (95% confidence interval, 1.2-7.4) and 4.3 (95% confidence interval, 1.3-14.5) for faster growing tumors., Conclusions: Our findings show that high cellular density and thromboses are significant independent predictors of faster growth in human GBM. This finding underlines the importance of hypercellularity as a criterion in glioma grading. Furthermore, our findings are concordant with hypotheses suggesting hypoxia triggered by thromboses to be relevant for growth of GBM., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Structural magnetic resonance imaging (MRI) and histopathologic tissue sampling are routinely performed as part of the diagnostic workup for patients with glioma. Because of the heterogeneous nature of gliomas, there is a risk of undergrading caused by histopathologic sampling errors. MRI has limitations in identifying tumor grade and type, detecting diffuse invasive growth, and separating recurrences from treatment induced changes. Positron emission tomography (PET) can provide quantitative information of cellular activity and metabolism, and may therefore complement MRI. In this report, we present the first patient with brain glioma examined with simultaneous PET/MRI using the amino acid tracer 18 F-fluciclovine ( 18 F-FACBC) for intraoperative image-guided surgery., Case Description: A previously healthy 60-year old woman was admitted to the emergency care with speech difficulties and a mild left-sided hemiparesis. MRI revealed a tumor that was suggestive of glioma. Before surgery, the patient underwent a simultaneous PET/MRI examination. Fused PET/MRI, T1, FLAIR, and intraoperative three-dimensional ultrasound images were used to guide histopathologic tissue sampling and surgical resection. Navigated, image-guided histopathologic samples were compared with PET/MRI image data to assess the additional value of the PET acquisition. Histopathologic analysis showed anaplastic oligodendroglioma in the most malignant parts of the tumor, while several regions were World Health Organization (WHO) grade II., Conclusions: 18 F-Fluciclovine uptake was found in parts of the tumor where regional WHO grade, cell proliferation, and cell densities were highest. This finding suggests that PET/MRI with this tracer could be used to improve accuracy in histopathologic tissue sampling and grading, and possibly for guiding treatments targeting the most malignant part of extensive and eloquent gliomas., (Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Glioblastomas are highly aggressive and heterogeneous tumors, both in terms of patient outcome and molecular profile. Magnetic resonance imaging of tumor growth could potentially reveal new insights about tumor biology noninvasively. The aim of this exploratory retrospective study was to investigate the prognostic potential of pretreatment growth rate of glioblastomas, after controlling for known prognostic factors., Methods: A growth model derived from clinical pretreatment postcontrast T 1 -weighted magnetic resonance imaging images was used to divide 106 glioblastoma patients into 2 groups. The "faster growth" group had tumors growing faster than expected based on their volume at diagnosis, whereas the "slower growth" group had tumors growing slower than expected. Associations between tumor growth and survival were examined by the use of multivariable Cox regression and logistic regression., Results: None of the known prognostic factors were significantly associated with tumor growth. An extended multivariable Cox model showed that during the first 12 months of follow-up, there was no significant difference in survival between faster and slower growing tumors. Beyond 12 months' follow-up, however, there was a significant, independent survival benefit in having a tumor with slower pretreatment growth. In a multiple logistic regression model including patients receiving both radiotherapy and chemotherapy (n = 82), slower pre-treatment growth of the tumor was shown to be a significant predictor of 2-year survival (odds ratio 4.4)., Conclusions: Pretreatment glioblastoma growth harbors prognostic information. Patients with slower growing tumors have higher odds of survival beyond 2 years, adjusted for other prognostic factors., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Assessment of size and growth are key radiological factors in low-grade gliomas (LGGs), both for prognostication and treatment evaluation, but the reliability of LGG-segmentation is scarcely studied. With a diffuse and invasive growth pattern, usually without contrast enhancement, these tumors can be difficult to delineate. The aim of this study was to investigate the intra-observer variability in LGG-segmentation for a radiologist without prior segmentation experience. Pre-operative 3D FLAIR images of 23 LGGs were segmented three times in the software 3D Slicer. Tumor volumes were calculated, together with the absolute and relative difference between the segmentations. To quantify the intra-rater variability, we used the Jaccard coefficient comparing both two (J2) and three (J3) segmentations as well as the Hausdorff Distance (HD). The variability measured with J2 improved significantly between the two last segmentations compared to the two first, going from 0.87 to 0.90 (p = 0.04). Between the last two segmentations, larger tumors showed a tendency towards smaller relative volume difference (p = 0.07), while tumors with well-defined borders had significantly less variability measured with both J2 (p = 0.04) and HD (p < 0.01). We found no significant relationship between variability and histological sub-types or Apparent Diffusion Coefficients (ADC). We found that the intra-rater variability can be considerable in serial LGG-segmentation, but the variability seems to decrease with experience and higher grade of border conspicuity. Our findings highlight that some criteria defining tumor borders and progression in 3D volumetric segmentation is needed, if moving from 2D to 3D assessment of size and growth of LGGs.

To facilitate a more widespread use of volumetric tumor segmentation in clinical studies, there is an urgent need for reliable, user-friendly segmentation software. The aim of this study was therefore to compare three different software packages for semi-automatic brain tumor segmentation of glioblastoma; namely BrainVoyagerTM QX, ITK-Snap and 3D Slicer, and to make data available for future reference. Pre-operative, contrast enhanced T1-weighted 1.5 or 3 Tesla Magnetic Resonance Imaging (MRI) scans were obtained in 20 consecutive patients who underwent surgery for glioblastoma. MRI scans were segmented twice in each software package by two investigators. Intra-rater, inter-rater and between-software agreement was compared by using differences of means with 95% limits of agreement (LoA), Dice's similarity coefficients (DSC) and Hausdorff distance (HD). Time expenditure of segmentations was measured using a stopwatch. Eighteen tumors were included in the analyses. Inter-rater agreement was highest for BrainVoyager with difference of means of 0.19 mL and 95% LoA from -2.42 mL to 2.81 mL. Between-software agreement and 95% LoA were very similar for the different software packages. Intra-rater, inter-rater and between-software DSC were ≥ 0.93 in all analyses. Time expenditure was approximately 41 min per segmentation in BrainVoyager, and 18 min per segmentation in both 3D Slicer and ITK-Snap. Our main findings were that there is a high agreement within and between the software packages in terms of small intra-rater, inter-rater and between-software differences of means and high Dice's similarity coefficients. Time expenditure was highest for BrainVoyager, but all software packages were relatively time-consuming, which may limit usability in an everyday clinical setting., Competing Interests: The authors have declared that no competing interests exist.

Background: Glioblastomas are primary malignant brain tumors with a dismal prognosis. Knowledge of growth rates and underlying growth dynamics is useful for understanding basic tumor biology, developing realistic tumor models, and planning treatment logistics., Methods: By using repeated pretreatment contrast-enhanced T1-weighted MRI scans from 106 patients (aged 26-83 years), we studied the growth dynamics of untreated glioblastomas in vivo. Growth rates were calculated as specific growth rates and equivalent volume doubling times. The fit of different possible growth models was assessed using maximum likelihood estimations., Results: There were large variations in growth rates between patients. The median specific growth rate of the tumors was 1.4% per day, and the equivalent volume doubling time was 49.6 days. Exploring 3 different tumor growth models showed similar statistical fit for a Gompertzian growth model and a linear radial growth model and worse fit for an exponential growth model. However, large tumors had significantly lower growth rates than smaller tumors, supporting the assumption that glioblastomas reach a plateau phase and thus exhibit Gompertzian growth., Conclusion: Based on the fast growth rate of glioblastoma shown in this study, it is evident that poor treatment logistics will influence tumor size before surgery and can cause significant regrowth before adjuvant treatment. Since there is a known association between tumor volume, extent of surgical resection, and response to adjuvant therapy, it is likely that waiting times play a role in patient outcomes., (© The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Acquired deficits following glioma resection may not only occur due to accidental resection of normal brain tissue. The possible importance of ischemic injuries in causing neurological deficits after brain tumor surgery is not much studied. We aimed to study the volume and frequency of early postoperative circulatory changes (i.e. infarctions) detected by diffusion weighted resonance imaging (DWI) in patients with surgically acquired neurological deficits compared to controls., Methods: We designed a 1 ∶ 1 matched case-control study in patients with diffuse gliomas (WHO grade II-IV) operated with 3D ultrasound guided resection. 42 consecutive patients with acquired postoperative dysphasia and/or new motor deficits were compared to 42 matched controls without acquired deficits. Controls were matched with respect to histopathology, preoperative tumor volumes, and eloquence of location. Two independent radiologists blinded for clinical status assessed the postoperative DWI findings., Results: Postoperative peri-tumoral infarctions were more often seen in patients with acquired deficits (63% versus 41%, p = 0.046) and volumes of DWI abnormalities were larger in cases than in controls with median 1.08 cm3 (IQR 0-2.39) versus median 0 cm3 (IQR 0-1.67), p = 0.047. Inter-rater agreement was substantial (67/82, κ = 0.64, p<0.001) for diagnosing radiological significant DWI abnormalities., Conclusion: Peri-tumoral infarctions were more common and were larger in patients with acquired deficits after glioma surgery compared to glioma patients without deficits when assessed by early postoperative DWI. Infarctions may be a frequent and underestimated cause of acquired deficits after glioma resection. DWI changes may be an attractive endpoint in brain tumor surgery with both good inter-rater reliability among radiologists and clinical relevance.

Objectives: Identification of eloquent brain areas in patients with intra-axial lesions is important to minimize the risk of neurological deficit. We performed a multicenter study comparing conventional 2-dimensional magnetic resonance imaging (MRI) for identification of the central sulcus to topographical MRI and blood-oxygenation-level-dependent functional MRI (BOLD-fMRI)., Methods: Seventy-seven unoperated patients with brain lesions were imaged at 1.5 or 3 T. The central sulcus was identified by an experienced neuroradiologist on 2-dimensional MRI, by topographic analysis of 3-dimensional MRI in BrainVoyager, and by BOLD-fMRI analysis in BrainVoyager or SPM5., Results: The central sulcus in the affected hemisphere was readily identified in a significantly higher percentage of patients by 2-dimensional MRI and topographical analysis (77/77 patients) compared to BOLD-fMRI (57 patients; P < 0.001). The topographical analysis identified a significantly larger portion of the total central sulcus than 2-dimensional MRI (P < 0.05). No differences were found between institutions, histological versus radiological diagnoses, MRI sequence parameters, age, or sex., Conclusions: Identification of the central sulcus is best performed using topographical analysis; however, 2-dimensional analysis may suffice for daily routine work.

Background: Functional neuronavigation with intraoperative 3-dimensional (3D) ultrasound may facilitate safer brain lesion resections than conventional neuronavigation., Objective: In this study, functional magnetic resonance imaging (fMRI) and diffusion tensor tractography (DTT) were used to map eloquent areas. We assessed the use of fMRI and DTT for preoperative assessments and determined whether using these data together with 3D ultrasound during surgery enabled safer lesion resection., Methods: We reviewed 51 consecutive patients with intracranial lesions in whom fMRI with or without DTT was used to map eloquent areas. To assess a possible impact of fMRI/DTT, we reviewed and analyzed the quality of the fMRI/DTT data, any change in therapeutic strategies, lesion to eloquent area distance (LEAD), extent of resection, and clinical outcome., Results: As a result of the fMRI/DTT mapping, the therapeutic strategies were changed in 4 patients. The median tumor residue for glioma patients was 11% (n = 33) and 0% for nonglioma lesions (n = 12). For gliomas, there was a significant correlation between decreasing LEAD and increasing tumor residue. Of the glioma patients, 42% underwent gross total resection (>or= 95%) and 12% suffered neurological worsening after surgery as a result of complications. Of glioma patients with an LEAD of

The hemodynamic response (HDR) function is the basis for standard functional magnetic resonance imaging (fMRI) analysis. HDR is influenced by white matter inflammation. Traumatic brain injury (TBI) is frequently accompanied by diffuse white matter injury, but the effect of this on the HDR has not been investigated. The aims of the present study were to describe the HDR in visual cortex and examine its relationship with the microstructure of the optic radiation in severe TBI survivors and controls. Ten severe TBI survivors without visual impairments, but with known diffuse axonal injury, and 9 matched controls underwent diffusion tensor imaging (DTI) and fMRI. From the fMRI time series obtained during brief randomized visual stimuli, blood oxygenation level-dependent (BOLD) signal changes for each subject were estimated in V1, and group HDR curves were produced. Standard between-group analysis of BOLD activation in V1 + V2 was performed. For each individual the optic radiations were identified and fractional anisotropy (FA) plus mean apparent diffusion coefficient (ADC(mean)) values for these tracts were calculated. Group HDR curves from the visual cortex were fully transposable between TBI survivors and controls, despite a significant reduction in FA in the optic radiation in TBI survivors. A significant correlation between BOLD signal in the visual cortex and FA values in the optical tract was present in controls, but not in TBI survivors. Between-group comparisons showed that TBI survivors had increased areas of activation in V1 and V2. The HDR appears to be intact in traumatic white matter damage, supporting the validity of using standard fMRI methodology to study neuroplasticity in TBI.

Introduction: The use of integrated pre- and intraoperative imaging may be useful when resecting brain lesions in close proximity to eloquent areas, such as the primary motor cortex and language cortices., Case Report: A 32-year-old woman with an arteriovenous malformation (AVM) located in the primary motor cortex underwent surgery using functional neuronavigation. Blood-oxygenation-level-dependent functional magnetic resonance imaging (BOLD fMRI) and diffusion tensor tractography (DTT) were used for preoperative mapping of primary motor areas and the corticospinal tracts, respectively. The BOLD fMRI activations and DTT tractograms were integrated into the neuronavigation system and visualized intraoperatively throughout the operation. Furthermore, stereoscopic visualizations of the angioarchitecture based on 3D MRI angiograms were used to rehearse the surgical approach to the feeder vessels. Finally, intraoperative ultrasound was used to locate and clip the feeding vessels., Conclusion: The AVM was carefully resected with the aid of the above-mentioned imaging techniques, and the intuitive usefulness of the techniques was further substantiated by the rewarding postoperative outcome.

Objective: The aims of this study of patients with high-grade gliomas in eloquent brain areas were 1) to assess the postoperative functional outcome, 2) to determine the extent of tumour resection in these difficult locations, 3) to evaluate the practical usefulness of navigated blood oxygenation level-dependent functional magnetic resonance imaging and diffusion tensor tractography., Patients and Methods: 25 consecutive patients were included in the study. The patients' gross functional neurological status was determined using the 7-step modified Rankin scale. The extent of tumour resection was determined using pre- and postoperative T(1)-weighted or T(1)-weighted, contrast-enhanced MRI images., Results: The average preoperative modified Rankin scale was 1.56+/-0.77, whereas the average postoperative modified Rankin scale was 1.08+/-1.29. There was a significant improvement in mean modified Rankin scale score after surgery. The mean percentage of residual tumour was calculated to 16+/-22% of the original tumour volume (median 8%). Blood oxygenation level-dependent functional magnetic resonance imaging and diffusion tensor tractography were performed in 23 and 18 patients, respectively. Blood oxygenation level-dependent functional magnetic resonance imaging and diffusion tensor tractography facilitated identification of probable functional regions in 91% and 94% of the respective investigations., Conclusion: We feel that the combination of blood oxygenation level-dependent functional magnetic resonance imaging, diffusion tensor tractography, and 3D ultrasound facilitated maximal tumour resection with minimal deficits. The method permits an image-based functional monitoring of the brain during surgery that may aid the preservation of motor and language function.

Objective: The aim of this study was to establish a robust set of motor tasks that could be used to functionally delineate the motor cortex with blood oxygenation level dependent functional magnetic resonance imaging (BOLD fMRI) at 3 T and produce precise functional maps for pre-operative planning and functional neuronavigation., Method: Twelve male and four female control subjects were recruited for this study which examined six different motor tasks. Finger-, tongue-, lip- and toe-movements, as well as isometric upper arm- and thigh-contraction tasks were conducted during separate scans on a 3 T MRI scanner. Furthermore, patients that previously had undergone similar motor tasks were reviewed, to evaluate whether this set of tasks was able to be adopted for use in a population of patients with brain lesions., Results: The results of this study indicated that the finger-, toe- and tongue-motor tasks were the most robust in identifying their respective primary motor area. Moreover, all three tasks activated regions at regular intervals along the convexity of the hemisphere, making it possible to functionally delineate the primary motor cortex in both healthy subjects and patients., Discussion: The motor tasks described in this study (toe, finger and tongue) were effective at localizing the primary motor cortex for the purposes of neurosurgical planning. These three tasks produced the highest success rate and resulted in activations at regular intervals along the convexity of the hemisphere, allowing the delineation of the entire motor strip even in the presence of edema and anatomical distortions.