Umbrella review and network meta-analysis of diagnostic imaging test accuracy studies in Differentiating between brain tumor progression versus pseudoprogression and radionecrosis.

PURPOSE: In this study we gathered and analyzed the available evidence regarding 17 different imaging modalities and performed network meta-analysis to find the most effective modality for the differentiation between brain tumor recurrence and post-treatment radiation effects. METHODS: We conducted a comprehensive systematic search on PubMed and Embase. The quality of eligible studies was assessed using the Assessment of Multiple Systematic Reviews-2 (AMSTAR-2) instrument. For each meta-analysis, we recalculated the effect size, sensitivity, specificity, positive and negative likelihood ratios, and diagnostic odds ratio from the individual study data provided in the original meta-analysis using a random-effects model. Imaging technique comparisons were then assessed using NMA. Ranking was assessed using the multidimensional scaling approach and by visually assessing surface under the cumulative ranking curves. RESULTS: We identified 32 eligible studies. High confidence in the results was found in only one of them, with a substantial heterogeneity and small study effect in 21% and 9% of included meta-analysis respectively. Comparisons between MRS Cho/NAA, Cho/Cr, DWI, and DSC were most studied. Our analysis showed MRS (Cho/NAA) and 18F-DOPA PET displayed the highest sensitivity and negative likelihood ratios. 18-FET PET was ranked highest among the 17 studied techniques with statistical significance. APT MRI was the only non-nuclear imaging modality to rank higher than DSC, with statistical insignificance, however. CONCLUSION: The evidence regarding which imaging modality is best for the differentiation between radiation necrosis and post-treatment radiation effects is still inconclusive. Using NMA, our analysis ranked FET PET to be the best for such a task based on the available evidence. APT MRI showed promising results as a non-nuclear alternative.

Management and Molecular Characterization of Intraventricular Glioblastoma: A Single-Institution Case Series.

While the central nervous system (CNS) tumor classification has increasingly incorporated molecular parameters, there is a paucity of literature reporting molecular alterations found in intraventricular glioblastoma (IVGBM), which are rare. We present a case series of nine IVGBMs, including molecular alterations found in standardized next-generation sequencing (NGS). We queried the clinical charts, operative notes, pathology reports, and radiographic images of nine patients with histologically confirmed IVGBM treated at our institution (1995-2021). Routine NGS was performed on resected tumor tissue of two patients. In this retrospective case series of nine patients (22% female, median (range) age: 64.3 (36-85) years), the most common tumor locations were the atrium of the right lateral ventricle (33%) and the septum pellucidum (33%). Five patients had preoperative hydrocephalus, which was managed with intraoperative external ventricular drains in three patients and ventriculoperitoneal shunts in one patient. Hydrocephalus was managed with subtotal resection of a fourth ventricular IVGBM in one patient. The most common surgical approach was transcortical intraventricular (56%). Gross total resection was achieved in two patients, subtotal resection was achieved in six patients, and one patient received a biopsy only. Immunohistochemistry for IDH1 R132H mutant protein was performed in four cases and was negative in all four. Genetic alterations common in glioblastoma, IDH-wildtype, were seen in two cases with available NGS data, including EGFR gene amplification, TERT promoter mutation, PTEN mutation, trisomy of chromosome 7, and monosomy of chromosome 10. Following surgical resection, four patients received adjuvant chemoradiation. Median survival among our cohort was 4.7 months (IQR: 0.9-5.8 months). Management of IVGBM is particularly challenging due to their anatomical location, presentation with obstructive hydrocephalus, and fast growth, necessitating prompt intervention. Additional studies are needed to better understand the genetic landscape of IVGBM compared to parenchymal glioblastoma and may further elucidate the unique pathophysiology of these rare tumors.

The Role of Preoperative Magnetic Resonance Imaging in Assessing Neurovascular Compression Before Microvascular Decompression in Trigeminal Neuralgia.

BACKGROUND: Preoperative magnetic resonance imaging (MRI) is a standard component of the preoperative clinical workup for patients before microvascular decompression (MVD). However, its ability to accurately exclude neurovascular compression of the trigeminal nerve is not well understood. METHODS: We retrospectively reviewed 1020 patients with available preoperative MRI data before microvascular decompression. General patient demographics and clinical characteristics were collected for each case. We recorded both evidence of neurovascular conflict on preoperative MRI radiology notes and intraoperative compression from operative notes. Sensitivity, specificity, positive predictive value, and negative predictive value were determined for general MRI, high-resolution MRI, and non-high resolution. RESULTS: Overall, preoperative MRI before MVD showed a sensitivity of 75.8%, specificity of 65.8%, positive predictive value of 92.4%, and negative predictive value of 33.3% in predicting neurovascular compression of the trigeminal nerve. In particular, MRI was unable to identify 21.0% cases of sole arterial compression, 42.5% cases of sole venous compression, and combined arterial and venous compression in 18.5% of cases. A total of 958 patients (93.9%) underwent high-resolution preoperative MRI with skull base sequences. This imaging showed a sensitivity of 75.6%, specificity of 66.9%, positive predictive value of 92.5% and a negative predictive value of 33.4% in predicting trigeminal nerve neurovascular compression. Non-high-resolution MRI showed a sensitivity of 78.8%, specificity of 50.0%, positive predictive value of 89.1%, and negative predictive value of 31.3%. The negative predictive values of general, high-resolution, and non-high-resolution MRIs were all <50%. CONCLUSIONS: Preoperative MRI may offer a high predictive value for neurovascular conflict and should be part of the standard preoperative care workup for patients with trigeminal neuralgia. However, lack of neurovascular conflict on preoperative imaging is not sufficient to exclude patients from undergoing MVD.

BRAF V600E-Mutant Glioblastoma with Extracranial Metastases Responsive to Combined BRAF and MEK Targeted Inhibition: A Case Report.

Recent advancements in understanding the biology of glioblastomas (GBM) and increasing adoption of genomic sequencing in oncology practice have led to the discovery of several targetable mutations in these cancers. Among them, the BRAF V600E mutation can be found in approximately 3% of GBM. Despite the aggressive nature of GBM, metastatic disease is rarely observed. While there are growing data utilizing BRAF-targeting strategies in patients with GBM, data examining their efficacy in cases of metastatic GBM are lacking. We present the case of a 46-year-old female with GBM, isocitrate dehydrogenase (IDH)-wildtype and O6-methylguanine-DNA methyltransferase promoter (MGMT) unmethylated, BRAF V600E-mutant, and MYC amplified with extra-central nervous system spread to the spine and lung. Four months after completion of treatment with standard chemoradiation and temozolomide, the patient developed severe back pain, leading to the eventual discovery of her metastatic disease. Based on the presence of the BRAF V600E mutation, the patient was treated with and achieved an intracranial and systemic response to combination BRAF-MEK targeted inhibition for 9 months before evidence of progression.

Automated eloquent cortex localization in brain tumor patients using multi-task graph neural networks.

Localizing the eloquent cortex is a crucial part of presurgical planning. While invasive mapping is the gold standard, there is increasing interest in using noninvasive fMRI to shorten and improve the process. However, many surgical patients cannot adequately perform task-based fMRI protocols. Resting-state fMRI has emerged as an alternative modality, but automated eloquent cortex localization remains an open challenge. In this paper, we develop a novel deep learning architecture to simultaneously identify language and primary motor cortex from rs-fMRI connectivity. Our approach uses the representational power of convolutional neural networks alongside the generalization power of multi-task learning to find a shared representation between the eloquent subnetworks. We validate our method on data from the publicly available Human Connectome Project and on a brain tumor dataset acquired at the Johns Hopkins Hospital. We compare our method against feature-based machine learning approaches and a fully-connected deep learning model that does not account for the shared network organization of the data. Our model achieves significantly better performance than competing baselines. We also assess the generalizability and robustness of our method. Our results clearly demonstrate the advantages of our graph convolution architecture combined with multi-task learning and highlight the promise of using rs-fMRI as a presurgical mapping tool.

Identification of the Somatomotor Network from Language Task-based fMRI Compared with Resting-State fMRI in Patients with Brain Lesions.

Background Resting-state functional MRI (rs-fMRI) is a potential alternative to task-based functional MRI (tb-fMRI) for somatomotor network (SMN) identification. Brain networks can also be generated from tb-fMRI by using independent component analysis (ICA). Purpose To investigate whether the SMN can be identified by using ICA from a language task without a motor component, the sentence completion functional MRI (sc-fMRI) task, compared with rs-fMRI. Materials and Methods The sc-fMRI and rs-fMRI scans in patients who underwent presurgical brain mapping between 2012 and 2016 were analyzed, using the same imaging parameters (other than scanning time) on a 3.0-T MRI scanner. ICA was performed on rs-fMRI and sc-fMRI scans with use of a tool to separate data sets into their spatial and temporal components. Two neuroradiologists independently determined the presence of the dorsal SMN (dSMN) and ventral SMN (vSMN) on each study. Groups were compared by using t tests, and logistic regression was performed to identify predictors of the presence of SMNs. Results One hundred patients (mean age, 40.9 years ± 14.8 [standard deviation]; 61 men) were evaluated. The dSMN and vSMN were identified in 86% (86 of 100) and 76% (76 of 100) of rs-fMRI scans and 85% (85 of 100) and 69% (69 of 100) of sc-fMRI scans, respectively. The concordance between rs-fMRI and sc-fMRI for presence of dSMN and vSMN was 75% (75 of 100 patients) and 53% (53 of 100 patients), respectively. In 10 of 14 patients (71%) where rs-fMRI did not show the dSMN, sc-fMRI demonstrated it. This rate was 67% for the vSMN (16 of 24 patients). Conclusion In the majority of patients, independent component analysis of sentence completion task functional MRI scans reliably demonstrated the somatomotor network compared with resting-state functional MRI scans. Identifying target networks with a single sentence completion scan could reduce overall functional MRI scanning times by eliminating the need for separate motor tasks. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Field and Birn in this issue.

A novel radiographic marker of sarcopenia with prognostic value in glioblastoma.

OBJECTIVE: Sarcopenia is an important prognostic consideration in surgical oncology that has received relatively little attention in brain tumor patients. Temporal muscle thickness (TMT) has recently been proposed as a novel radiographic marker of sarcopenia that can be efficiently obtained within existing workflows. We investigated the prognostic value of TMT in primary and progressive glioblastoma. METHODS: TMT measurements were performed on magnetic resonance images of 384 patients undergoing 541 surgeries for glioblastoma. Relationships between TMT and clinical characteristics were examined on bivariate analysis. Optimal TMT cutpoints were established using maximally selected rank statistics. Predictive value of TMT upon postoperative survival (PS) was assessed using Cox proportional hazards regression adjusted for age, sex, Karnofsky performance status (KPS), Stupp protocol completion, extent of resection, and tumor molecular markers. RESULTS: Average TMT for the primary and progressive glioblastoma cohorts was 9.55 mm and 9.40 mm, respectively. TMT was associated with age (r = -0.14, p = 0.0008), BMI (r = 0.29, p < 0.0001), albumin (r = 0.11, p = 0.0239), and KPS (r = 0.11, p = 0.0101). Optimal TMT cutpoints for the primary and progressive cohorts were ≤ 7.15 mm and ≤ 7.10 mm, respectively. High TMT was associated with increased Stupp protocol completion (p = 0.001). On Cox proportional hazards regression, high TMT predicted increased PS in progressive [HR 0.47 (95% confidence interval (CI)) 0.25-0.90), p = 0.023] but not primary [HR 0.99 (95% CI 0.64-1.51), p = 0.949] glioblastoma. CONCLUSIONS: TMT correlates with important prognostic variables in glioblastoma and predicts PS in patients with progressive, but not primary, disease. TMT may represent a pragmatic neurosurgical biomarker in glioblastoma that could inform treatment planning and perioperative optimization.

Role of Functional Magnetic Resonance Imaging in the Presurgical Mapping of Brain Tumors.

When planning for brain tumor resection, a balance between maximizing resection and minimizing injury to eloquent brain parenchyma is paramount. The advent of blood oxygenation level-dependent functional magnetic resonance (fMR) imaging has allowed researchers and clinicians to reliably measure physiologic fluctuations in brain oxygenation related to neuronal activity with good spatial resolution. fMR imaging can offer a unique insight into preoperative planning for brain tumors by identifying eloquent areas of the brain affected or spared by the neoplasm. This article discusses the fMR imaging techniques and their applications in neurosurgical planning.

Preoperative BMI Predicts Postoperative Weight Gain in Adult-onset Craniopharyngioma.

CONTEXT: Craniopharyngiomas, while benign, have the highest morbidity of all nonmalignant sellar tumors. Studies on weight and metabolic outcomes in adult-onset craniopharyngioma (AOCP) remain sparse. OBJECTIVE: To examine postsurgical weight and metabolic outcomes in AOCP and to identify any clinical predictors of weight gain. METHODS: Retrospective chart review of patients with AOCP who underwent surgery between January 2014 and May 2019 in a single pituitary center. The study included 45 patients with AOCP with a minimum follow-up of 3 months. Median follow-up time was 26 months (interquartile range [IQR] 10-44). Main outcome measures were the changes in weight/body mass index (BMI), metabolic comorbidities, and pituitary deficiencies between preoperative and last follow-up. RESULTS: Both weight and BMI were higher at last follow-up, with a mean increase of 3.4 kg for weight (P = .015) and 1.15 kg/m2 for BMI (P = .0095). Median % weight change was 2.7% (IQR -1.1%, 8.8%). Obesity rate increased from 37.8% at baseline to 55.6% at last follow-up. One-third of patients had ~15% median weight gain. The prevalence of metabolic comorbidities at last follow-up was not different from baseline. Pituitary deficiencies increased postoperatively, with 58% of patients having ≥3 hormonal deficiencies. Preoperative BMI was inversely associated with postoperative weight gain, which remained significant after adjusting for age, sex, race, tumor, and treatment characteristics. Patients with ≥3 hormonal deficiencies at last follow-up also had higher postoperative weight gain. CONCLUSION: In this AOCP cohort, those with a lower BMI at the preoperative visit had higher postoperative weight gain. Our finding may help physicians better counsel patients and provide anticipatory guidance on postoperative expectations and management.

A Multi-Scale Spatial and Temporal Attention Network on Dynamic Connectivity to Localize The Eloquent Cortex in Brain Tumor Patients.

We present a deep neural network architecture that combines multi-scale spatial attention with temporal attention to simultaneously localize the language and motor areas of the eloquent cortex from dynamic functional connectivity data. Our multi-scale spatial attention operates on graph-based features extracted from the connectivity matrices, thus honing in on the inter-regional interactions that collectively define the eloquent cortex. At the same time, our temporal attention model selects the intervals during which these interactions are most pronounced. The final stage of our model employs multi-task learning to differentiate between the eloquent subsystems. Our training strategy enables us to handle missing eloquent class labels by freezing the weights in those branches while updating the rest of the network weights. We evaluate our method on resting-state fMRI data from one synthetic dataset and one in-house brain tumor dataset while using task fMRI activations as ground-truth labels for the eloquent cortex. Our model achieves higher localization accuracies than conventional deep learning approaches. It also produces interpretable spatial and temporal attention features which can provide further insights for presurgical planning. Thus, our model shows translational promise for improving the safety of brain tumor resections.

Functional Magnetic Resonance Imaging Activation Optimization in the Setting of Brain Tumor-Induced Neurovascular Uncoupling Using Resting-State Blood Oxygen Level-Dependent Amplitude of Low Frequency Fluctuations.

The goal of this study was to demonstrate that a novel resting state BOLD ALFF (amplitude of low frequency fluctuations)-based correction method can substantially enhance the detectability of motor task activation in the presence of tumor-induced neurovascular uncoupling (NVU). Twelve de novo brain tumor patients who underwent comprehensive clinical BOLD fMRI exams including task fMRI and resting state fMRI (rsfMRI) were evaluated. Each patient displayed decreased/absent task fMRI activation in the ipsilesional primary motor cortex in the absence of corresponding motor deficit or suboptimal task performance, consistent with NVU. Z-score maps for the motor tasks were obtained from general linear model (GLM) analysis (reflecting motor activation vs. rest). ALFF maps were calculated from rsfMRI data. Precentral and postcentral gyri in contralesional (CL) and ipsilesional (IL) hemispheres were parcellated using an Automated Anatomical Labeling (AAL) template for each patient. A novel ALFF-based correction method was used to identify the NVU affected voxels in the ipsilesional primary motor cortex (PMC), and a correction factor was applied to normalize the baseline Z-scores for these voxels. In all cases, substantially greater activation was seen on post-ALFF correction motor activation maps within the ipsilesional precentral gyri than in the pre-ALFF correction activation maps. We have demonstrated the feasibility of a new resting state ALFF-based technique for effective correction of brain tumor-related NVU in the primary motor cortex.

Repeatability of language fMRI lateralization and localization metrics in brain tumor patients.

To assess the within-subject intra-scan session repeatability of language functional MRI (fMRI) activation maps in patients with brain tumors who were undergoing presurgical fMRI as part of their preoperative clinical workup. Sentence completion (SC) and silent word generation (SWG) tasks were used for language localization and hemispheric lateralization for identifying the primary language cortex. Within-subject repeatability for each of these paradigms was assessed in right-handed patients-37 for SC and 78 for SWG. Repeatability of activation maps between consecutive runs of the same task within the same scan session was evaluated by comparing lateralization indexes in holohemispheric and regional language areas. Displacement of center of activation between consecutive runs was also used to assess the repeatability of activation maps. Holohemispheric and regional language lateralization results demonstrated high intra-subject intra-scan repeatability when lateralization indices were calculated using threshold-dependent and threshold-independent approaches. The high repeatability is demonstrated both when centers of mass of activation are considered within key eloquent regions of the brain, such as Broca's area and Wernicke's area, as well as in larger more inclusive expressive and receptive language regions. We examined two well-known and widely accepted language tasks that are known to activate eloquent language cortex. We have demonstrated very high degree of repeatability at a single-subject level within single scan sessions of language mapping in a large cohort of brain tumor patients undergoing presurgical fMRI across several years at our institution.

Phase II study of rituximab given in conjunction with standard chemotherapy in primary central nervous system lymphoma (PCNSL): a trial of the ECOG-ACRIN cancer research group (E1F05).

BACKGROUND: Therapy of primary CNS lymphoma (PCNSL) has focused on multi-agent chemotherapy designed to cross the blood brain barrier. Rituximab has demonstrated activity in PCNSL. E1F05 is an ECOG-ACRIN multicenter phase 2 prospective trial of rituximab with high-dose methotrexate (HD-MTX)-based chemotherapy similar to the RTOG 93-10 regimen, omitting radiotherapy. METHODS: Immunocompetent patients with newly diagnosed PCNSL received HD-MTX 3.5g/m2 with vincristine every two weeks for 5 doses; procarbazine for 7 days in weeks 1, 5, and 9; cytarabine 3g/m2/day IV for 2 days in weeks 11 and 14; a dexamethasone taper over 6 weeks; and rituximab 375mg/m2 IV infusion 3 times per week for weeks 1-4. Subjects with CSF involvement received intrathecal methotrexate 12mg every two weeks. RESULTS: Twenty-six patients were enrolled; median age was 57. Sixteen subjects (65%) completed treatment per protocol; the most common reason for discontinuation was adverse events, and 2 subjects discontinued due to progressive disease (PD). Complete response (CR) + unconfirmed CR (CRu) was 16/25 (64%), overall response rate was 20/25 (80%), and 4/25(16%) had PD as best response. Median progression free survival (PFS) was 34 months, and median overall survival has not been reached at 40 months' median follow up. Two year PFS was 63%. The most common grade 3-4 toxicities were hematologic. CONCLUSION: The addition of rituximab to multi-agent chemotherapy is well tolerated. Outcomes are comparable to or better than those seen in RTOG 93-10, which included RT. These and other results suggest rituximab has activity in the CNS. [ECOG-ACRIN E1F05]. CLINICAL TRIAL REGISTRATION: NCT00335140, clinicaltrials.gov.

Quantitative assessment of changes in diffusion tensor imaging (DTI) metrics along the courses of the cortico-ponto-cerebellar tracts secondary to supratentorial human brain glial tumors.

BACKGROUND: The cortico-ponto-cerebellar tract (CPCT) is the largest projection pathway, which synapses at the pons. Remote effects of supratentorial brain tumors have not been evaluated along the infratentorial course of the CPCT. AIM: The purpose of this study is to evaluate the possible lateralization of the diffusion tensor metrics of the affected CPCT in patients with supratentorial brain tumor. METHODS AND RESULTS: We included 39 patients with 29 left-sided tumors (LST) and 10 right-sided tumors, retrospectively. We measured the magnitude of changes of the fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of the CPCT prior to the brain surgery at the level of crus cerebri and middle cerebellar peduncle. Regions of interest (ROIs) were placed on the lateral side of crus cerebri, and ROI-1 (anterior 1/3), ROI-2 (middle 1/3), ROI-3 (posterior 1/3), and ROI-4 were placed at the level of middle cerebellar peduncle. We hypothesized that there would be decreased FA and increased ADC values of the ipsilesional CPCT compared with contralesional CPCT. Ipsilesional FA values were decreased with simultaneous increased ADC value along the CPCT compared with contralesional CPCT in following ROIs, ROI-1 (LST FA: P = .005, ADC: P = .037) and ROI-3 (LST FA: P = .049, ADC: P = .049), respectively. Affected ROI-4 in LST cases also showed lower FA values, although not statistically significant. CONCLUSION: We observed a statistically significant FA value decrease and ADC increase along the left ROI-1 and ROI-3 as well as the nonstatistically significant FA decrease of the left ROI-4 at the second neuron level when there was a related supratentorial tumor. These findings are suggestive of presynaptic and postsynaptic microstructural changes of these tracts following the presynaptic involvement by a primary supratentorial brain tumor.

The effect of regadenoson on the integrity of the human blood-brain barrier, a pilot study.

Regadenoson is an FDA approved adenosine receptor agonist which increases blood-brain barrier (BBB) permeability in rodents. Regadenoson is used clinically for pharmacologic cardiac stress testing using SPECT or CT imaging agents that do not cross an intact BBB. This study was conducted to determine if standard doses of regadenoson transiently disrupt the human BBB allowing higher concentrations of systemically administered imaging agents to enter the brain. Patients without known intracranial disease undergoing clinically indicated pharmacologic cardiac stress tests were eligible for this study. They received regadenoson (0.4 mg) followed by brain imaging with either 99mTc-sestamibi for SPECT or visipaque for CT imaging. Pre- and post-regadenoson penetration of imaging agents into brain were quantified [SPECT: radioactive counts, CT: Hounsfield units (HU)] and compared using a matched-pairs t-test. Twelve patients (33% male, median 60 yo) were accrued: 7 SPECT and 5 CT. No significant differences were noted in pre- and post-regadenoson values using mean radionuclide counts (726 vs. 757) or HU (29 vs. 30). While animal studies have demonstrated that regadenoson transiently increases the permeability of the BBB to dextran and temozolomide, we were unable to document changes in the penetration of contrast agents in humans with intact BBB using the FDA approved doses of regadenoson for cardiac evaluation. Further studies are needed exploring alternate regadenoson dosing, schedules, and studies in patients with brain tumors; as transiently disrupting the BBB to improve drug entry into the brain is critical to improving the care of patients with CNS malignancies.

Presurgical brain mapping of the language network in patients with brain tumors using resting-state fMRI: Comparison with task fMRI.

PURPOSE: To compare language networks derived from resting-state fMRI (rs-fMRI) with task-fMRI in patients with brain tumors and investigate variables that affect rs-fMRI vs task-fMRI concordance. MATERIALS AND METHODS: Independent component analysis (ICA) of rs-fMRI was performed with 20, 30, 40, and 50 target components (ICA20 to ICA50) and language networks identified for patients presenting for presurgical fMRI mapping between 1/1/2009 and 7/1/2015. 49 patients were analyzed fulfilling criteria for presence of brain tumors, no prior brain surgery, and adequate task-fMRI performance. Rs-vs-task-fMRI concordance was measured using Dice coefficients across varying fMRI thresholds before and after noise removal. Multi-thresholded Dice coefficient volume under the surface (DiceVUS) and maximum Dice coefficient (MaxDice) were calculated. One-way Analysis of Variance (ANOVA) was performed to determine significance of DiceVUS and MaxDice between the four ICA order groups. Age, Sex, Handedness, Tumor Side, Tumor Size, WHO Grade, number of scrubbed volumes, image intensity root mean square (iRMS), and mean framewise displacement (FD) were used as predictors for VUS in a linear regression. RESULTS: Artificial elevation of rs-fMRI vs task-fMRI concordance is seen at low thresholds due to noise. Noise-removed group-mean DiceVUS and MaxDice improved as ICA order increased, however ANOVA demonstrated no statistically significant difference between the four groups. Linear regression demonstrated an association between iRMS and DiceVUS for ICA30-50, and iRMS and MaxDice for ICA50. CONCLUSION: Overall there is moderate group level rs-vs-task fMRI language network concordance, however substantial subject-level variability exists; iRMS may be used to determine reliability of rs-fMRI derived language networks.

Presurgical fMRI and DTI for the Prediction of Perioperative Motor and Language Deficits in Primary or Metastatic Brain Lesions.

BACKGROUND AND PURPOSE: To determine whether lesion to activation distance (LAD) on presurgical blood-oxygen-level-dependent functional magnetic resonance imaging (fMRI) and degree of white matter involvement by primary or metastatic brain lesions predict perioperative motor and language deficits. METHODS: We retrospectively evaluated 76 patients with intra-axial brain lesions referred for presurgical fMRI and diffusion tensor imaging (DTI). We measured expressive, receptive, global language and motor LAD and assessed degree of involvement of the corticospinal tract (CST) and the superior longitudinal fasciculus (SLF). We performed a Wilcoxon rank-sum test to determine whether the LAD and the degree of CST/SLF involvement were statistically significantly different between patients with and without preoperative or postoperative neurological deficits. RESULTS: In preoperatively symptomatic patients, motor and expressive language LAD were significantly lower (z = -3.78, P = .0002, and z = -2.51, P = .01, respectively) than in asymptomatic patients. No significant difference was noted in LAD between postoperative symptomatic and asymptomatic patients, except for a trend level effect for motor LAD (P = .07). The degree of CST involvement was significantly different between symptomatic and asymptomatic patients (z = 3.40, P = .0007 and z = 2.97, P = .003, respectively, for pre- and postoperative motor deficits).The degree of SLF involvement was significantly different between preoperatively (but not postoperatively) symptomatic and asymptomatic patients (z = 2.85, P = .004). CONCLUSION: Presurgical motor and expressive language LAD as well as degree of tract involvement on DTI are predictive of preoperative but not postoperative deficits, except for CST DTI and (trend level) motor LAD; inability of language LAD to predict postoperative deficits suggests that preoperative fMRI is valuable to neurosurgeons in avoiding resection of eloquent cortex.

Multiphase computed tomography for localization of parathyroid disease in patients with primary hyperparathyroidism: How many phases do we really need?

BACKGROUND: Multiphase computed tomography (CT) involves multiple cervical CT acquisitions to accurately identify hyperfunctional parathyroid glands, thus increasing radiation exposure to the patient. We hypothesized that only 2 cervical acquisitions, instead of the conventional 4, would provide equivalent localization information and halve the radiation exposure. METHODS: We identified 53 consecutive patients with primary hyperparathyroidism who underwent multiphase CT before parathyroidectomy. All scans were reinterpreted first using 2 phases then using all 4 phases. The accuracies of interpretations were determined with surgical findings serving as the standard of reference. RESULTS: Sixty-four hyperfunctional parathyroid glands were resected with a mean weight of 394.3 mg. Two-phase CT lateralized the hyperfunctional glands in 38 patients with a sensitivity, positive predictive value (PPV), and accuracy of 100%, 71.7%, and 71.7%, respectively. Four-phase CT lateralized the hyperfunctional glands in 39 patients with a sensitivity, PPV, and accuracy of 95.1%, 76.5%, and 73.6%, respectively. For quadrant localization, the accuracy of 2-phase and 4-phase CT was 50.9% and 52.8%, respectively. CONCLUSION: Our results suggest that 2-phase and 4-phase CT provide an equivalent diagnostic accuracy in localizing hyperfunctional parathyroid glands. The reduced radiation exposure to the patient may make 2-phase acquisitions a more acceptable alternative for preoperative localization.