Early rise of glutamate-glutamine levels in mild cognitive impairment: Evidence for emerging excitotoxicity.

BACKGROUND: Use proton magnetic resonance spectroscopy (1H-MRS) non invasive technique to assess the modifications of glutamate-glutamine (Glx) and gammaaminobutyric acid (GABA) brain levels in patients reporting a cognitive complain METHODS: Posterior cingular cortex 1H-MRS spectra of 46 patients (19 male, 27 female) aged 57 to 87 years (mean : 73.32 ± 7.33 years) with a cognitive complaint were examined with a MEGA PRESS sequence at 3T, and compounds Glutamateglutamine (Glx), GABA, Creatine (Cr) and NAA were measured. From this data the metabolite ratios Glx/Cr, GABA/Cr and NAA/Cr were calculated. In addition, all patient performed the Mini Mental State Evaluation (MMSE) and 2 groups were realized with the clinical threshold of 24. RESULTS: 16 patients with MMSE 〈 24 and 30 patients with MMSE 〉 24. Significant increase of Glx/Cr in PCC of patients with MMSE 〈 24 compared to patients with MMSE 〉 24. Moreover, GABA/Cr ratio exhibited a trend for a decrease in PCC between the two groups, while they showed a significant decrease NAA/Cr ratio. CONCLUSION: Our results concerning Glx are in agreement with a physiopathological hypothesis involving a biphasic variation of glutamate levels associated with excitotoxicity, correlated with the clinical evolution of the disease. These observations suggest that MRS assessment of glutamate levels could be helpful for both diagnosis and classification of cognitive impairment in stage.

Assessment of Compliance and Impact of the COVID-19 RSNA Recommendations on Radiology Departments: A French Survey.

Online supplemental material is available for this article. See also the editorial by Tuite in this issue.

TEMOBIC: Phase II Trial of Neoadjuvant Chemotherapy for Unresectable Anaplastic Gliomas: An ANOCEF Study.

LESSONS LEARNED: Treatment with temozolomide and BCNU was associated with substantial response and survival rates for patients with unresectable anaplastic glioma, suggesting potential therapeutic alternative for these patients. The optimal treatment for unresectable large anaplastic gliomas remains debated. BACKGROUND: The optimal treatment for unresectable large anaplastic gliomas remains debated. METHODS: Adult patients with histologically proven unresectable anaplastic oligodendroglioma or mixed gliomas (World Health Organization [WHO] 2007) were eligible. Treatment consisted of BCNU (150 mg/m2 ) and temozolomide (110 mg/m2 for 5 days) every 6 weeks for six cycles before radiotherapy. RESULTS: Between December 2005 and December 2009, 55 patients (median age of 53.1 years; range, 20.5-70.2) were included. Forty percent of patients presented with wild-type IDH1 gliomas, and 30% presented with methylated MGMT promoter. Median progression-free survival (PFS), centralized PFS, and overall survival (OS) were 16.6 (95% confidence interval [CI], 12.8-20.3), 15.4 (95% CI, 10.0-20.8), and 25.4 (95% CI, 17.5-33.2) months, respectively. Complete and partial responses under chemotherapy were observed for 28.3% and 17% of patients, respectively. Radiotherapy completion was achieved for 75% of patients. Preservation of functional status and self-care capability (Karnofsky performance status [KPS] ≥70) were preserved until disease progression for 69% of patients. Grade ≥ 3 toxicities were reported for 52% of patients, and three deaths were related to treatment. By multivariate analyses including age and KPS, IDH mutation was associated with better prognostic for both PFS and OS, whereas MGMT promoter methylation was associated with better OS. CONCLUSION: The association of BCNU and temozolomide upfront is active for patients with unresectable anaplastic gliomas, but toxicity limits its use.

Efficacy of Chest CT for COVID-19 Pneumonia Diagnosis in France.

Background The role and performance of chest CT in the diagnosis of the coronavirus disease 2019 (COVID-19) pandemic remains under active investigation. Purpose To evaluate the French national experience using chest CT for COVID-19, results of chest CT and reverse transcription polymerase chain reaction (RT-PCR) assays were compared together and with the final discharge diagnosis used as the reference standard. Materials and Methods A structured CT scan survey (NCT04339686) was sent to 26 hospital radiology departments in France between March 2, 2020, and April 24, 2020. These dates correspond to the peak of the national COVID-19 epidemic. Radiology departments were selected to reflect the estimated geographic prevalence heterogeneities of the epidemic. All symptomatic patients suspected of having COVID-19 pneumonia who underwent both initial chest CT and at least one RT-PCR test within 48 hours were included. The final discharge diagnosis, based on multiparametric items, was recorded. Data for each center were prospectively collected and gathered each week. Test efficacy was determined by using the Mann-Whitney test, Student t test, χ2 test, and Pearson correlation coefficient. P < .05 indicated a significant difference. Results Twenty-six of 26 hospital radiology departments responded to the survey, with 7500 patients entered; 2652 did not have RT-PCR test results or had unknown or excess delay between the RT-PCR test and CT. After exclusions, 4824 patients (mean age, 64 years ± 19 [standard deviation], 2669 male) were included. With final diagnosis as the reference, 2564 of the 4824 patients had COVID-19 (53%). Sensitivity, specificity, negative predictive value, and positive predictive value of chest CT in the diagnosis of COVID-19 were 2319 of 2564 (90%; 95% CI: 89, 91), 2056 of 2260 (91%; 95% CI: 91, 92), 2056 of 2300 (89%; 95% CI: 87, 90), and 2319 of 2524 (92%; 95% CI: 91, 93), respectively. There was no significant difference for chest CT efficacy among the 26 geographically separate sites, each with varying amounts of disease prevalence. Conclusion Use of chest CT for the initial diagnosis and triage of patients suspected of having coronavirus disease 2019 was successful. © RSNA, 2021 Online supplemental material is available for this article.

Efficacy of chest CT scan for COVID-19 diagnosis in a low prevalence and incidence region.

OBJECTIVES: Value of chest CT was mainly studied in area of high COVID-19 incidence. The aim of this study was therefore to evaluate chest CT performances to diagnose COVID-19 pneumonia with regard to RT-PCR as reference standard in a low incidence area. METHODS: A survey was sent to radiology department in 4 hospitals in an administrative French region of weak disease prevalence (3.4%). Study design was approved by the local institutional review board and recorded on the clinicaltrial.gov website (NCT04339686). Written informed consent was waived due to retrospective anonymized data collection. Patients who underwent a RT-PCR and a chest CT scan within 48 h for COVID-19 pneumonia suspicion were consecutively included. Diagnostic accuracy including the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of chest CT regarding RT-PCR as reference standard were calculated. RESULTS: One hundred twenty-nine patients had abnormal chest CT findings compatible with a COVID-19 pneumonia (26%, 129/487). Among the 358 negative chest CT findings, 3% (10/358) were RT-PCR positive. Chest CT sensitivity, specificity, positive, and negative predictive value were respectively 87% (IC95: 85, 89; 69/79), 85% (IC95: 83, 87; 348/408), 53% (IC95: 50, 56; 69/129), and 97% (IC95: 95, 99; 348/358). CONCLUSIONS: In a low prevalence area, chest CT scan is a good diagnostic tool to rule out COVID-19 infection among symptomatic suspected patients. KEY POINTS: • In a low prevalence area (3.4% in the administrative area and 5.8% at mean in the study) chest CT sensitivity and specificity for diagnosing COVID-19 pneumonia were 87% and 85% respectively. • In patients with negative chest CT for COVID-19 pneumonia, the negative predictive value of COVID-19 infection was 97% (348/358 subjects). • Performance of CT was equivalent between the 4 centers participating to this study.

Comparison of Spinal Cord Stimulation vs. Dorsal Root Ganglion Stimulation vs. Association of Both in Patients with Refractory Chronic Back and/or Lower Limb Neuropathic Pain: An International, Prospective, Randomized, Double-Blinded, Crossover Trial (BOOST-DRG Study).

While spinal cord stimulation (SCS) is a well-established therapy to address refractory persistent spinal pain syndrome after spinal surgery (PSPS-T2), its lack of spatial selectivity and reported discomfort due to positional effects can be considered as significant limitations. As alternatives, new waveforms, such as burst stimulation and different spatial neural targets, such as dorsal root ganglion stimulation (DRGS), have shown promising results. Comparisons between DRGS and standard SCS, or their combination, have never been studied on the same patients. "BOOST DRG" is the first prospective, randomized, double-blinded, crossover study to compare SCS vs. DRGS vs. SCS+DRGS. Sixty-six PSPS-T2 patients will be recruited internationally in three centers. Before crossing over, patients will receive each stimulation modality for 1 month, using tonic conventional stimulation. After 3 months, stimulation will consist in switching to burst for 1 month, and patients will choose which modality/waveform they receive and will then be reassessed at 6 and 12 months. In addition to our primary outcome based on pain rating, this study is designed to assess quality of life, functional disability, psychological distress, pain surface coverage, global impression of change, medication quantification, adverse events, brain functional imaging and electroencephalography, with the objective being to provide a multidimensional insight based on composite pain assessment.

COVID-19 impact assessment on the French radiological centers: a nationwide survey.

PURPOSE: To determine the impact of the COVID-19 on the CT activities in French radiological centers during the epidemic peak. MATERIALS AND METHODS: A cross-sectional prospective CT scan survey was conducted between March 16 and April 12, 2020, in accordance with the local IRB. Seven hundred nine radiology centers were invited to participate in a weekly online survey. Numbers of CT examinations related to COVID-19 including at least chest (CTcovid) and whole chest CT scan activities (CTchest) were recorded each week. A sub-analysis on French departments was performed during the 4 weeks of the study. The impact of the number of RT-PCRs (reverse transcriptase polymerase chain reactions) on the CT workflow was tested using two-sample t test and Pearson's test. RESULTS: Five hundred seventy-seven structures finally registered (78%) with mean response numbers of 336 ± 18.9 (323; 351). Mean CTchest activity per radiologic structure ranged from 75.8 ± 133 (0-1444) on week 12 to 99.3 ± 138.6 (0-1147) on week 13. Mean ratio of CTcovid on CTchest varied from 0.36 to 0.59 on week 12 and week 14 respectively. There was a significant relationship between the number of RT-PCR performed and the number of CTcovid (r = 0.73, p = 3.10-16) but no link with the number of positive RT-PCR results. CONCLUSION: In case of local high density COVID-19, CT workflow is strongly modified and redirected to the management of these specific patients. KEY POINTS: • Over the 4-week survey period, 117,686 chest CT (CTtotal) were performed among the responding centers, including 61,784 (52%) CT performed for COVID-19 (CTcovid). • Across the country, the ratio CTcovid/CTtotal varied from 0.36 to 0.59 and depended significantly on the local epidemic density (p = 0.003). • In clinical practice, in a context of growing epidemic, in France, chest CT was used as a surrogate to RT-PCR for patient triage.

Circadian Rhythms in Exudative Age-Related Macular Degeneration: The Key Role of the Canonical WNT/ß-Catenin Pathway.

Age-related macular degeneration (AMD) is considered as the main worldwide cause of blindness in elderly adults. Exudative AMD type represents 10 to 15% of macular degeneration cases, but is the main cause of vision loss and blindness. Circadian rhythm changes are associated with aging and could further accelerate it. However, the link between circadian rhythms and exudative AMD is not fully understood. Some evidence suggests that dysregulation of circadian functions could be manifestations of diseases or could be risk factors for the development of disease in elderly adults. Biological rhythms are complex systems interacting with the environment and control several physiological pathways. Recent findings have shown that the dysregulation of circadian rhythms is correlated with exudative AMD. One of the main pathways involved in exudative AMD is the canonical WNT/ß-catenin pathway. Circadian clocks have a main role in some tissues by driving the circadian expression of genes involved in physiological and metabolic functions. In exudative AMD, the increase of the canonical WNT/ß-catenin pathway is enhanced by the dysregulation of circadian rhythms. Exudative AMD progression is associated with major metabolic reprogramming, initiated by aberrant WNT/ß-catenin pathway, of aerobic glycolysis. This review focuses on the interest of circadian rhythm dysregulation in exudative AMD through the aberrant upregulation of the canonical WNT/ß-catenin pathway.

Mathematical Modeling of Substrates Fluxes and Tumor Growth in the Brain.

The aim of this article is to show how a tumor can modify energy substrates fluxes in the brain to support its own growth. To address this question we use a modeling approach to explain brain nutrient kinetics. In particular we set up a system of 17 equations for oxygen, lactate, glucose concentrations and cells number in the brain. We prove the existence and uniqueness of nonnegative solutions and give bounds on the solutions. We also provide numerical simulations.

Interactions Between the Canonical WNT/Beta-Catenin Pathway and PPAR Gamma on Neuroinflammation, Demyelination, and Remyelination in Multiple Sclerosis.

Multiple sclerosis (MS) is marked by neuroinflammation and demyelination with loss of oligodendrocytes in the central nervous system. The immune response is regulated by WNT/beta-catenin pathway in MS. Activated NF-kappaB, a major effector of neuroinflammation, and upregulated canonical WNT/beta-catenin pathway positively regulate each other. Demyelinating events present an upregulation of WNT/beta-catenin pathway, whereas proper myelinating phases show a downregulation of WNT/beta-catenin pathway essential for the promotion of oligodendrocytes precursors cells proliferation and differentiation. The activation of WNT/beta-catenin pathway results in differentiation failure and impairment in remyelination. However, PI3K/Akt pathway and TCF7L2, two downstream targets of WNT/beta-catenin pathway, are upregulated and promote proper remyelination. The interactions of these signaling pathways remain unclear. PPAR gamma activation can inhibit NF-kappaB, and can also downregulate the WNT/beta-catenin pathway. PPAR gamma and canonical WNT/beta-catenin pathway act in an opposite manner. PPAR gamma agonists appear as a promising treatment for the inhibition of demyelination and the promotion of proper remyelination through the control of both NF-kappaB activity and canonical WNT/beta-catenin pathway.

Imaging practice in low-grade gliomas among European specialized centers and proposal for a minimum core of imaging.

OBJECTIVE: Imaging studies in diffuse low-grade gliomas (DLGG) vary across centers. In order to establish a minimal core of imaging necessary for further investigations and clinical trials in the field of DLGG, we aimed to establish the status quo within specialized European centers. METHODS: An online survey composed of 46 items was sent out to members of the European Low-Grade Glioma Network, the European Association of Neurosurgical Societies, the German Society of Neurosurgery and the Austrian Society of Neurosurgery. RESULTS: A total of 128 fully completed surveys were received and analyzed. Most centers (n = 96, 75%) were academic and half of the centers (n = 64, 50%) adhered to a dedicated treatment program for DLGG. There were national differences regarding the sequences enclosed in MRI imaging and use of PET, however most included T1 (without and with contrast, 100%), T2 (100%) and TIRM or FLAIR (20, 98%). DWI is performed by 80% of centers and 61% of centers regularly performed PWI. CONCLUSION: A minimal core of imaging composed of T1 (w/wo contrast), T2, TIRM/FLAIR, PWI and DWI could be identified. All morphologic images should be obtained in a slice thickness of ≤ 3 mm. No common standard could be obtained regarding advanced MRI protocols and PET. IMPORTANCE OF THE STUDY: We believe that our study makes a significant contribution to the literature because we were able to determine similarities in numerous aspects of LGG imaging. Using the proposed "minimal core of imaging" in clinical routine will facilitate future cooperative studies.

Demyelination in Multiple Sclerosis: Reprogramming Energy Metabolism and Potential PPARγ Agonist Treatment Approaches.

Demyelination in multiple sclerosis (MS) cells is the site of several energy metabolic abnormalities driven by dysregulation between the opposed interplay of peroxisome proliferator-activated receptor γ (PPARγ) and WNT/ß-catenin pathways. We focus our review on the opposing interactions observed in demyelinating processes in MS between the canonical WNT/ß-catenin pathway and PPARγ and their reprogramming energy metabolism implications. Demyelination in MS is associated with chronic inflammation, which is itself associated with the release of cytokines by CD4⁺ Th17 cells, and downregulation of PPARγ expression leading to the upregulation of the WNT/ß-catenin pathway. Upregulation of WNT/ß-catenin signaling induces activation of glycolytic enzymes that modify their energy metabolic behavior. Then, in MS cells, a large portion of cytosolic pyruvate is converted into lactate. This phenomenon is called the Warburg effect, despite the availability of oxygen. The Warburg effect is the shift of an energy transfer production from mitochondrial oxidative phosphorylation to aerobic glycolysis. Lactate production is correlated with increased WNT/ß-catenin signaling and demyelinating processes by inducing dysfunction of CD4⁺ T cells leading to axonal and neuronal damage. In MS, downregulation of PPARγ decreases insulin sensitivity and increases neuroinflammation. PPARγ agonists inhibit Th17 differentiation in CD4⁺ T cells and then diminish release of cytokines. In MS, abnormalities in the regulation of circadian rhythms stimulate the WNT pathway to initiate the demyelination process. Moreover, PPARγ contributes to the regulation of some key circadian genes. Thus, PPARγ agonists interfere with reprogramming energy metabolism by directly inhibiting the WNT/ß-catenin pathway and circadian rhythms and could appear as promising treatments in MS due to these interactions.

Exploration and Identification of Cortico-Cerebellar-Brainstem Closed Loop During a Motivational-Motor Task: an fMRI Study.

The cerebellum is involved not only in motor coordination, training, and memory, but also in cognition and emotion. Lobule VI in particular belongs to sensorimotor, salience, and executive cerebellar networks. This study aims to determine whether lobule VI would constitute an integrative interface between motor and cognitive/emotional circuits during a motor task with verbal encouragement, likely in conjunction with the basal ganglia (reward and motivational system). We used fMRI to identify specific recruitment of cerebellar and striatal systems during physical performance using two motor tasks with and without encouragement. We found that: (i) Force results were higher during verbal encouragement than during basal condition in all participants. (ii) The anterior part of the right lobule VI was activated by motor execution in both tasks, while its posterior part was specifically activated by verbal encouragement. (iii) The closed-connectivity loop maintained motivation induced by verbal encouragement between cerebral and cerebellar through the red nucleus and striatal network. Therefore, right lobule VI is a hub-controlling sensorimotor and motivates aspects of motor performance in relation with the red nucleus and the ventral striatum. These results could have important implications for extrapyramidal and multisystem degenerative diseases.

Effects of cannabidiol interactions with Wnt/ß-catenin pathway and PPARγ on oxidative stress and neuroinflammation in Alzheimer's disease.

Alzheimer's disease (AD) is a neurodegenerative disease, in which the primary etiology remains unknown. AD presents amyloid beta (Aß) protein aggregation and neurofibrillary plaque deposits. AD shows oxidative stress and chronic inflammation. In AD, canonical Wingless-Int (Wnt)/ß-catenin pathway is downregulated, whereas peroxisome proliferator-activated receptor γ (PPARγ) is increased. Downregulation of Wnt/ß-catenin, through activation of glycogen synthase kinase-3ß (GSK-3ß) by Aß, and inactivation of phosphatidylinositol 3-kinase/Akt signaling involve oxidative stress in AD. Cannabidiol (CBD) is a non-psychotomimetic phytocannabinoid from Cannabis sativa plant. In PC12 cells, Aß-induced tau protein hyperphosphorylation is inhibited by CBD. This inhibition is associated with a downregulation of p-GSK-3ß, an inhibitor of Wnt pathway. CBD may also increase Wnt/ß-catenin by stimulation of PPARγ, inhibition of Aß and ubiquitination of amyloid precursor protein. CBD attenuates oxidative stress and diminishes mitochondrial dysfunction and reactive oxygen species generation. CBD suppresses, through activation of PPARγ, pro-inflammatory signaling and may be a potential new candidate for AD therapy.

Development of a nomogram combining clinical staging with (18)F-FDG PET/CT image features in non-small-cell lung cancer stage I-III.

PURPOSE: Our goal was to develop a nomogram by exploiting intratumour heterogeneity on CT and PET images from routine (18)F-FDG PET/CT acquisitions to identify patients with the poorest prognosis. METHODS: This retrospective study included 116 patients with NSCLC stage I, II or III and with staging (18)F-FDG PET/CT imaging. Primary tumour volumes were delineated using the FLAB algorithm and 3D Slicer™ on PET and CT images, respectively. PET and CT heterogeneities were quantified using texture analysis. The reproducibility of the CT features was assessed on a separate test-retest dataset. The stratification power of the PET/CT features was evaluated using the Kaplan-Meier method and the log-rank test. The best standard metric (functional volume) was combined with the least redundant and most prognostic PET/CT heterogeneity features to build the nomogram. RESULTS: PET entropy and CT zone percentage had the highest complementary values with clinical stage and functional volume. The nomogram improved stratification amongst patients with stage II and III disease, allowing identification of patients with the poorest prognosis (clinical stage III, large tumour volume, high PET heterogeneity and low CT heterogeneity). CONCLUSION: Intratumour heterogeneity quantified using textural features on both CT and PET images from routine staging (18)F-FDG PET/CT acquisitions can be used to create a nomogram with higher stratification power than staging alone.

Epileptic seizures in diffuse low-grade gliomas in adults.

Diffuse low-grade gliomas are highly epileptogenic brain tumours. We aimed to explore the natural course of epileptic seizures, their predictors and the prognostic significance of their occurrence in adult patients harbouring a diffuse low-grade glioma. An observational retrospective multicentre study examined 1509 patients with diffuse low-grade gliomas to identify mutual interactions between tumour characteristics, tumour course and epileptic seizures. At diagnosis, 89.9% of patients had epileptic seizures. Male gender (P = 0.003) and tumour location within functional areas (P = 0.001) were independent predictors of a history of epileptic seizures at diagnosis. Tumour volume, growth velocity, cortical location, histopathological subtype or molecular markers did not significantly affect epileptic seizure occurrence probability. Prolonged history of epileptic seizures (P < 0.001), insular location (P = 0.003) and tumour location close to functional areas (P = 0.038) were independent predictors of uncontrolled epileptic seizures at diagnosis. Occurrence of epileptic seizures (P < 0.001), parietal (P = 0.029) and insular (P = 0.002) locations were independent predictors of uncontrolled epileptic seizures after oncological treatment. Patient age (P < 0.001), subtotal (P = 0.007) and total (P < 0.001) resections were independent predictors of total epileptic seizure control after oncological treatment. History of epileptic seizures at diagnosis and total surgical resection were independently associated with increased malignant progression-free (P < 0.001 and P < 0.001) and overall (P < 0.001 and P = 0.016) survivals. Epileptic seizures are independently associated with diffuse low-grade glioma prognosis. Patients diagnosed with epileptic seizures and those with complete and early surgical resections have better oncological outcomes. Early and maximal surgical resection is thus required for diffuse low-grade gliomas, both for oncological and epileptological purposes.

On a minimal model for hemodynamics and metabolism of lactate: application to low grade glioma and therapeutic strategies.

WHO II low grade glioma evolves inevitably to anaplastic transformation. Magnetic resonance imaging is a good non-invasive way to watch it, by hemodynamic and metabolic modifications, thanks to multinuclear spectroscopy (1)H/(31)P. In this work we study a multi-scale minimal model of hemodynamics and metabolism applied to the study of gliomas. This mathematical analysis leads us to a fast-slow system. The control of the position of the stationary point brings to the concept of domain of viability. Starting from this system, the equations bring to light the parameters that push glioma cells out of their domain of viability. Four fundamental factors are highlighted. The first two are cerebral blood flow and the rate of lactate transport through monocarboxylate transporters, which must be reduced in order to push glioma out of its domain of viability. Another factor is the intra arterial lactate, which must be increased. The last factor is pH, indeed a decrease of intra cellular pH could interfere with glioma growth. These reflections suggest that these four parameters could lead to new therapeutic strategies for the management of low grade gliomas.

Functional outcome in low-ASPECTS (0-5) acute ischemic stroke treated with mechanical thrombectomy: impact of laterality explored in a single-center study.

Background: There is no consensus regarding the influence of infarct laterality in patients with acute ischemic stroke due to anterior large vessel occlusion (AIS-LVO) treated with mechanical thrombectomy (MT), particularly in low-ASPECT (0-5) patients who were excluded from the initial MT studies and that participated in dedicated randomized-controlled trials that do not consider the side of the occlusion. We aimed to evaluate the role of infarct laterality on the clinical outcome in low-ASPECT AIS patients treated with MT. Material and methods: We retrospectively analyzed our institutional stroke database in our Thrombectomy-Capable Stroke Center (TCSC), including patient characteristics, procedural variables, and outcomes, between January 2015 and January 2022. Patients with acute intracranial ICA and/or proximal MCA occlusions with ASPECT ≤ 5 either on CT or MRI were included and divided into 2 groups according to the location of ischemia. The primary endpoint was a good clinical outcome at 90 days (modified Rankin Scale (mRS) score of 0-3). Results: Between January 2015 and November 2021, 817 MT were performed, of which 82 were low-ASPECT (10.0%): 41 left-sided and 41 right-sided strokes. The rates of good clinical outcome were 30.8% (12/41) for the left-sided group and 43.6% (17/41) for the right-sided group, with a p-value of 0.349. The morality rate showed no significant difference between the two groups: 39.0% (16/41) in the right stroke group and 36.6% (15/41) in the left stroke group. Conclusion: The clinical outcome was not significantly influenced by stroke laterality. The results of this single-center retrospective study indicate either a lack of strength or equal value in performing mechanical thrombectomy regardless of stroke laterality.

Machine learning decision tree models for multiclass classification of common malignant brain tumors using perfusion and spectroscopy MRI data.

Background: To investigate the contribution of machine learning decision tree models applied to perfusion and spectroscopy MRI for multiclass classification of lymphomas, glioblastomas, and metastases, and then to bring out the underlying key pathophysiological processes involved in the hierarchization of the decision-making algorithms of the models. Methods: From 2013 to 2020, 180 consecutive patients with histopathologically proved lymphomas (n = 77), glioblastomas (n = 45), and metastases (n = 58) were included in machine learning analysis after undergoing MRI. The perfusion parameters (rCBVmax, PSRmax) and spectroscopic concentration ratios (lac/Cr, Cho/NAA, Cho/Cr, and lip/Cr) were applied to construct Classification and Regression Tree (CART) models for multiclass classification of these brain tumors. A 5-fold random cross validation was performed on the dataset. Results: The decision tree model thus constructed successfully classified all 3 tumor types with a performance (AUC) of 0.98 for PCNSLs, 0.98 for GBM and 1.00 for METs. The model accuracy was 0.96 with a RSquare of 0.887. Five rules of classifier combinations were extracted with a predicted probability from 0.907 to 0.989 for that end nodes of the decision tree for tumor multiclass classification. In hierarchical order of importance, the root node (Cho/NAA) in the decision tree algorithm was primarily based on the proliferative, infiltrative, and neuronal destructive characteristics of the tumor, the internal node (PSRmax), on tumor tissue capillary permeability characteristics, and the end node (Lac/Cr or Cho/Cr), on tumor energy glycolytic (Warburg effect), or on membrane lipid tumor metabolism. Conclusion: Our study shows potential implementation of machine learning decision tree model algorithms based on a hierarchical, convenient, and personalized use of perfusion and spectroscopy MRI data for multiclass classification of these brain tumors.

Diagnostic and Therapeutic Issues in Glioma Using Imaging Data: The Challenge of Numerical Twinning.

Glial tumors represent the leading etiology of primary brain tumors. Their particularities lie in (i) their location in a highly functional organ that is difficult to access surgically, including for biopsy, and (ii) their rapid, anisotropic mode of extension, notably via the fiber bundles of the white matter, which further limits the possibilities of resection. The use of mathematical tools enables the development of numerical models representative of the oncotype, genotype, evolution, and therapeutic response of lesions. The significant development of digital technologies linked to high-resolution NMR exploration, coupled with the possibilities offered by AI, means that we can envisage the creation of digital twins of tumors and their host organs, thus reducing the use of physical sampling.