Magnetic resonance imaging,susceptibility weighted imaging and quantitative susceptibility mapping findings of pantothenate kinase-associated neurodegeneration

Pantothenate kinase-associated neurodegeneration (PKAN) is extremely rare. In this study, we aimed to evaluate the magnetic resonance imaging (MRI) findings of PKAN patients. Conventional MRI and susceptibility weighted imaging (SWI) sequences and quantitative susceptibility mapping (QSM) maps of six patients from three PKAN families and eight healthy male volunteers were retrospectively analyzed. Iron content was represented by QSM values. The typical eye-of-the-tiger sign (n = 4) and hyperintensity (n = 2) of the bilateral globus pallidus (GP) were observed on T2WI sequences. The SWI signal was low (n = 5), and the QSM values were obviously higher (n = 2), which manifested as a reversed eye-of-the-tiger sign (n = 4) and hyperintensity (n = 2) on the QSM map. The QSM values were higher in the bilateral central GP, bilateral peripheral GP, and bilateral substantia nigra (SN) and lower in the left red nucleus (RN) compared with the healthy controls. No significant differences were observed in the right RN, bilateral thalamus and bilateral occipital regions. Low signals on SWI sequences and high QSM values with a reversed eye-of-the-tiger sign on QSM maps are important for the diagnosis of PKAN, especially in patients who do not show the eye-of-the-tiger sign in early stages. The eye-of-the-tiger sign observed on T2WI is helpful in diagnosing PKAN when the disease has already progressed to an advanced stage.     

Serial MRI alterations of pediatric patients with beta-propeller protein associated neurodegeneration (BPAN)

Background and PurposeBeta-propeller protein-associated neurodegeneration (BPAN) is one subtype of neurodegeneration with brain iron accumulation. It is difficult to diagnose BPAN due to the non-specificity of their clinical findings and neuroimaging in early childhood. We experienced four pediatric patients with serial brain MRI and evaluated the alteration of the findings through their course.MethodsWe retrospectively reviewed the clinical findings and 21 MRI findings of the four patients with genetically confirmed pediatric BPAN. We also performed a quantitative MR assessment using the quantitative susceptibility mapping (QSM) values of the globus pallidus (GP), substantia nigra (SN), and deep cerebellar nuclei (DCN) compared to 10 age-matched disease controls.ResultsOnly one patient was suspected of BPAN based on imaging findings before the genetic diagnosis was made. The other three patients could not be suspected until their Whole-exome sequencings (WES) done. In all four cases, no abnormal signals were noted in the GP and SN at the initial brain MRI, but hypointensities were observed after the ages of 4–7 years on T2-weighted images and after the ages of 2–7 years on susceptibility-weighted images. In three patients, T2 hyperintensity in the bilateral DCN was persistently observed throughout the observational period. Three patients showed transient T2 hyperintensity and swelling in the GP, SN and/or DCN during the episodes of pyrexia and seizures. The other findings included cerebral and cerebellar atrophy, thinning of the corpus callosum, and delayed myelination. The QSM values of the GP and SN were significantly higher in the patients compared to the controls (P = 0.005, respectively), but that of the DCN did not differ significantly (P = 0.16).ConclusionBrain MRI is a useful method to establish the early diagnosis of BPAN.     

A multiparametric MRI study of structural brain damage in dementia with lewy bodies: A comparison with Alzheimer's disease

IntroductionDifferential diagnosis between dementia with Lewy bodies (DLB) and Alzheimer's disease (AD) is crucial for an adequate patients' management but might be challenging. We investigated with advanced MRI techniques gray (GM) and white matter (WM) damage in DLB patients compared to those with AD.Methods24 DLB patients, 26 age- and disease severity-matched AD patients, and 20 age and sex-matched controls performed clinical and neuropsychological assessment, and brain structural and diffusion-tensor MRI. We measured GM atrophy using voxel-based morphometry, WM hyperintensities (WMH) using a local thresholding segmentation technique, and normal-appearing WM (NAWM) damage using tract-based spatial statistic.ResultsDLB and AD patients exhibited mild-to-moderate-stage dementia. Compared to controls, GM damage was diffuse in AD, while limited to bilateral thalamus and temporal regions in DLB. Compared to DLB, AD patients exhibited GM atrophy in bilateral fronto-temporal and occipital regions. DLB and AD patients showed higher WMH load than controls, with no differences among each other. WMH in DLB were diffuse with relative prevalence in posterior parietal-occipital regions. Compared to controls, both DLB and AD patients showed reduced microstructural integrity of the main supratentorial and infratentorial NAWM tracts. AD patients exhibited greater posterior NAWM damage than DLB.ConclusionsDLB showed prominent WM degeneration compared to the limited GM atrophy, while in AD both tissue compartments were severely involved. In DLB, NAWM microstructural degeneration was independent of WMH, thus revealing two possible underlying processes. Different pathophysiological mechanisms are likely to drive GM and WM damage distribution in DLB and AD.     

Can we predict intraoperative blood loss in meningioma patients? Application of dynamic susceptibility contrast-enhanced magnetic resonance imaging

PurposeTo evaluate the potential of quantitative dynamic susceptibility contrast (DSC) perfusion MR imaging parameters as imaging biomarkers for predicting intraoperative blood loss in meningioma.MethodsFifty-one non-embolized meningioma patients who had undergone preoperative DSC perfusion MR imaging were retrospectively included. The corrected relative cerebral blood volume (rCBV) and leakage coefficient (K₂) of the entire enhanced tumor were obtained using leakage correction. Tumor volume, location, grade, and other clinical variables, were also analyzed. To investigate the vascularity and vascular permeability of meningiomas, and their correlation with predicting estimated blood loss (EBL) using preoperative DSC perfusion MR imaging, the authors proposed an index reflecting the inherent tendency of meningiomas to bleed after controlling volume (i.e., EBL/cm³). Simple regression was performed to identify predictors of EBL/cm³; subsequently, the relevant variables included in the stepwise multiple linear regression.ResultsOn univariate analysis, EBL/cm³ was correlated with rCBV (r = 0.677; P < 0.001), K₂ (r = 0.294; P = 0.036), and tumor volume (r = –0.312, P = 0.026). EBL/cm³ was not correlated with age (P = 0.873), sex (P = 0.404), tumor location (P = 0.327), or histological grade (P = 0.230). On multiple linear regression, rCBV (β = 0.663 [0.463–0.864], B = 1.293 [0.903–1.684; P < 0.001) and K₂ (β = 0.260 [0.060–0.460], B = 2.277 [0.523–4.031], P = 0.012), were the only independent predictors of EBL/cm³.ConclusionThe rCBV and K₂ derived from DSC perfusion MR imaging in meningiomas may serve as feasible tools for clinicians to predict intraoperative blood loss and facilitate surgical planning.     

MRI features of demyelinating disease associated with anti-MOG antibodies in adults

The spectrum of Myelin Oligodendrocytes Glycoprotein (MOG) antibody disease constitutes a recently described challenging entity, referring to a relatively new spectrum of autoimmune disorders with antibodies against MOG predominantly involving the optic nerve and spinal cord. The purpose of this article is to describe MRI features of MOG-AD involvement in the optic nerves, spinal cord and the brain of adults.     

Review of synthetic MRI in pediatric brains: Basic principle of MR quantification,its features,clinical applications,and limitations

Quantitative magnetic resonance imaging (MRI) with multislice, multi-echo, and multi-delay acquisition enables simultaneous quantification of R₁ and R₂ relaxation rates, proton density, and the B₁ field in a single acquisition, and requires only about 6 minutes for full-head coverage. Using dedicated SyMRI software, radiologists can generate any contrast-weighted image by manipulating the acquisition parameters, including repetition time, echo time, and inversion time. Moreover, automatic brain tissue segmentation, volumetry, and myelin measurement can also be performed. Using the SyMRI approach, a shorter scan time, an objective examination, and personalized MR imaging parameters can be obtained in daily clinical pediatric imaging. Here we summarize and review the use of SyMRI in imaging of the pediatric brain, including the basic principles of MR quantification along with its features, clinical applications, and limitations.     

Correlation between magnetic resonance imaging characteristics and BRAF alteration status in individuals with optic pathway/hypothalamic pilocytic astrocytomas

Background and purposeMost individuals with optic pathway/hypothalamic pilocytic astrocytoma (OPHPA) harbor either the BRAF V600E mutation or KIAA1549-BRAF fusion (K-B). This study aimed to investigate the imaging characteristics of OPHPA in relation to BRAF alteration status.Materials and methodsSeven cases of OPHPA harboring either the BRAF V600E mutation or K-B fusion were included in the study. Preoperative magnetic resonance imaging (MRI) was assessed for degree of T2 hyperintensity on T2-weighted images (T2WI) and the ratio of nonenhancing T2 or fluid-attenuated inversion recovery (FLAIR) hyperintense area to the contrast enhanced area (CE) on gadolinium-enhanced-T1 weighted images (T2/FLAIR-CE mismatch). The T2 signal intensity was normalized to cerebrospinal fluid (T2/CSF) for both the V600E and K-B group and compared. T2/FLAIR-CE mismatch was assessed by calculating the proportion of the tumor volume of nonenhancing high T2 signal intensity to the whole lesion (nonenhancing and enhancing components).ResultsFour and three cases of OPHPA harboring the BRAF V600E mutation and K-B, respectively, were analyzed. The T2/CSF value was higher in the K-B group than in the V600E group. Moreover, the V600E group had a larger T2/FLAIR-CE mismatch than the K-B group.ConclusionsThe BRAF alteration status in individuals with OPHPA was associated with preoperative MRI by focusing on T2 signal intensity and T2/FLAIR-CE mismatch. The BRAF V600E mutation was associated with a lower T2/CSF value and larger T2/FLAIR-CE mismatch, whereas K-B fusion was associated with a higher T2/CSF value and smaller T2/FLAIR-CE mismatch.     

Automated assessment of the substantia nigra on susceptibility map-weighted imaging using deep convolutional neural networks for diagnosis of Idiopathic Parkinson's disease

ObjectivesDespite its use in determining nigrostriatal degeneration, the lack of a consistent interpretation of nigrosome 1 susceptibility map-weighted imaging (SMwI) limits its generalized applicability. To implement and evaluate a diagnostic algorithm based on convolutional neural networks for interpreting nigrosome 1 SMwI for determining nigrostriatal degeneration in idiopathic Parkinson's disease (IPD).MethodsIn this retrospective study, we enrolled 267 IPD patients and 160 control subjects (125 patients with drug-induced parkinsonism and 35 healthy subjects) at our institute, and 24 IPD patients and 27 control subjects at three other institutes on approval of the local institutional review boards. Dopamine transporter imaging served as the reference standard for the presence or absence of abnormalities of nigrosome 1 on SMwI. Diagnostic performance was compared between visual assessment by an experienced neuroradiologist and the developed deep learning-based diagnostic algorithm in both internal and external datasets using a bootstrapping method with 10000 re-samples by the “pROC” package of R (version 1.16.2).ResultsThe area under the receiver operating characteristics curve (AUC) (95% confidence interval [CI]) per participant by the bootstrap method was not significantly different between visual assessment and the deep learning-based algorithm (internal validation, .9622 [0.8912–1.0000] versus 0.9534 [0.8779-0.9956], P = .1511; external validation, 0.9367 [0.8843-0.9802] versus 0.9208 [0.8634-0.9693], P = .6267), indicative of a comparable performance to visual assessment.ConclusionsOur deep learning-based algorithm for assessing abnormalities of nigrosome 1 on SMwI was found to have a comparable performance to that of an experienced neuroradiologist.     

Radiological classification of dementia from anatomical MRI assisted by machine learning-derived maps

Background and purposeMany artificial intelligence tools are currently being developed to assist diagnosis of dementia from magnetic resonance imaging (MRI). However, these tools have so far been difficult to integrate in the clinical routine workflow. In this work, we propose a new simple way to use them and assess their utility for improving diagnostic accuracy.Materials and methodsWe studied 34 patients with early-onset Alzheimer's disease (EOAD), 49 with late-onset AD (LOAD), 39 with frontotemporal dementia (FTD) and 24 with depression from the pre-existing cohort CLIN-AD. Support vector machine (SVM) automatic classifiers using 3D T1 MRI were trained to distinguish: LOAD vs. Depression, FTD vs. LOAD, EOAD vs. Depression, EOAD vs. FTD. We extracted SVM weight maps, which are tridimensional representations of discriminant atrophy patterns used by the classifier to take its decisions and we printed posters of these maps. Four radiologists (2 senior neuroradiologists and 2 unspecialized junior radiologists) performed a visual classification of the 4 diagnostic pairs using 3D T1 MRI. Classifications were performed twice: first with standard radiological reading and then using SVM weight maps as a guide.ResultsDiagnostic performance was significantly improved by the use of the weight maps for the two junior radiologists in the case of FTD vs. EOAD. Improvement was over 10 points of diagnostic accuracy.ConclusionThis tool can improve the diagnostic accuracy of junior radiologists and could be integrated in the clinical routine workflow.     

Associations of carotid artery flow parameters with MRI markers of cerebral small vessel disease and patterns of brain atrophy

ObjectivesA growing body of evidence links age related brain pathologies to systemic vascular processes. We aimed to study the prevalence and interrelations between magnetic resonance imaging (MRI) markers of cerebral small vessel disease and patterns of brain atrophy, and their association to carotid duplex ultrasound flow parameters.Materials and methodsWe investigated a population based randomised cohort of older adults (n=391) aged 70-87, part of the Swedish Good Aging in Skåne Study. Peak systolic and end diastolic velocities of the carotid arteries were measured by ultrasound, and resistivity- and pulsatility indexes were calculated. Subjects with increased peak systolic velocity indicating carotid stenosis were excluded from analysis. Nine MRI findings were rated by visual scales: white matter changes, pontine white matter changes, microbleeds, lacunar infarctions, medial temporal lobe atrophy, global cortical atrophy, parietal atrophy, precuneus atrophy and central atrophy.ResultsMRI pathologies were found in 80% of subjects. Mean end diastolic velocity in common carotid arteries was inversely associated with white matter hyperintensities (OR=0.92; p=0.004), parietal lobe atrophy (OR=0.94; p=0.039), global cortical atrophy (OR=0.90; p=0.013), precuneus atrophy (OR=0.94; p=0.022), “number of CSV pathologies” (β=-0.07; p<0.001) and “MRI-burden score” (β=-0.11; p<0.001), after adjustment for age and sex. The latter three were also associated with pulsatility and resistivity indexes.ConclusionsLow carotid end diastolic velocity, as well as increased carotid resistivity and pulsatility, were associated with signs of cerebral small vessel disease and patterns of brain atrophy, indicating a vascular component in the process of brain aging.     

Consensus Guidelines of the French Society of Neuroradiology (SFNR) on the use of Gadolinium-Based Contrast agents (GBCAs) and related MRI protocols in Neuroradiology

Gadolinium-based contrast agents (GBCAs) are used in up to 35% of magnetic resonance imaging (MRI) examinations and are associated with an excellent safety profile. Nevertheless, two main issues have arisen in the last two decades: the risk of nephrogenic systemic fibrosis and the risk of gadolinium deposition and retention. As a first step, this article reviews the different categories of GBCAs available in neuroradiology, their issues, and provides updates regarding the use of these agents in routine daily practice. Recent advances in MRI technology, as well as the development of new MRI sequences, have made GBCA injection avoidable in many indications, especially in patients with chronic diseases when iterative MRIs are required and when essential diagnostic information can be obtained without contrast enhancement. These recent advances also lead to changes in recommended MRI protocols. Thus, in a second step, this review focuses on consensus concerning brain MRI protocols in 10 common situations (acute ischemic stroke, intracerebral hemorrhage, cerebral venous thrombosis, multiple sclerosis, chronic headache, intracranial infection, intra- and extra-axial brain tumors, vestibular schwannoma and pituitary adenoma). The latter allowing the standardization of practices in neuroradiology. Recommendations were also made concerning the use of GBCAs in neuroradiology, based on evidence in the literature and/or by consensus between the different coauthors.     

Signal changes in enhanced T1-weighted images related to gadolinium retention: A three-time-point imaging study

Background and PurposeConcern has grown about the finding of gadolinium deposits in the brain after administering gadolinium-based contrast agents (GBCAs). The mechanism is unclear, and related questions remain unanswered, including the stability over time. Therefore, we conducted a three-time-point study to explore T1-weighted (W) signal changes in the dentate nucleus (DN) and globus pallidus (GP), after the first, fifth, and tenth injections of either a macrocyclic agent (gadoterate meglumine) or a linear agent (gadobenate dimeglumine).Materials and methodsFor this retrospective, multicenter, longitudinal study, two groups of 18 (gadoterate meglumine) and 19 (gadobenate dimeglumine) patients were identified. The evolution of the signal over time was analyzed using DN/pons (DN/P) and GP/thalamus (GP/T) ratios.ResultsDN/P and GP/T ratios tended to increase after the fifth administration of gadobenate dimeglumine, following by a downward trend. A trend in a decrease in DN/P and GP/T ratios were found after the fifth and tenth administrations of gadoterate meglumine.ConclusionAfter exposure to gadobenate dimeglumine, the signal intensity (SI) tended to increase after the fifth injection owing to gadolinium accumulation, however, a SI increase was not found after the tenth administration supporting the hypothesis of a slow elimination of the previously retained gadolinium (wash-out effect) from the brain or of a change in form (by dechelation), causing the signal to fade. No increasing SI was found in the DN and GP after exclusive exposure to gadoterate meglumine, thus confirming its stability. We found, instead, a trend for a significative gadolinium elimination over time.     

MRI characteristics of MOG-Ab associated disease in adults: An update

Our knowledge of the radiological spectrum of myelin oligodendrocyte glycoprotein antibody associated disease (MOGAD) is growing rapidly. An update on the radiological features of the disease, and its evolution is thus necessary. Magnetic resonance imaging (MRI) has an increasingly important role in the differential diagnosis of MOGAD particularly from aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder (AQP4-NMOSD), and multiple sclerosis (MS). Differentiating these conditions is of prime importance because the management is different between the three inflammatory diseases, and thus could prevent further attack-related disability. Therefore, identifying the MRI features suggestive of MOGAD has diagnostic and prognostic implications. We herein review optic nerve, spinal cord and the brain MRI findings from MOGAD adult patients, and compare them to AQP4-NMOSD and MS.     

Exoscopic resection of atrial intraventricular meningiomas using a navigation-assisted channel-based trans-sulcal approach: Case series and literature review

The surgical treatment of atrial meningiomas carries unique challenges. Recent advancements have aimed to optimize visualization and minimize insult to adjacent tissue. To investigate outcomes following resection of atrial meningiomas using an integrated tubular retraction system with neuro-navigated exoscope. A retrospective analysis of surgical outcomes in consecutive patients who underwent surgical resection of atrial meningiomas via an exoscopic tubular retraction system at three university hospital institutions. Four patients harboring intraventricular meningiomas in the atrium of the lateral ventricle were treated using an integrated navigation-assisted, channel-based trans-sulcal approach via a left temporal-occipital (1), right parieto-occipital (2), or left posterior-temporal (1) sulcal approach with exoscopic visualization. Indications for surgery included headaches (4/4, 100%), dizziness (1/4, 25%), or evidence of progression on imaging (3/4, 75%). Mean maximal tumor diameter was 25.5 mm (range 22–28 mm). No intraoperative complications were observed, and no conversion to a microscopic or open approach was required. Gross total resection (GTR) was obtained in all 4 cases. Median hospital length of stay was 3 days (range 3–4 days). Postoperative complications included homonymous hemianopsia (1) and transient bilateral lower extremity paresthesias (1). At 3-month follow up both complications had improved and all patients had returned to work. At last follow-up (3–24 months), 3 patients (75%) reported improvement of preoperative symptoms.Utilization of a channel-based, navigable retractor with the aid of an exoscope can be an excellent option for accessing the atrium of the lateral ventricles and for achieving complete surgical resection of atrial meningiomas.     

High-gamma modulation language mapping with stereo-EEG: A novel analytic approach and diagnostic validation

ObjectiveA novel analytic approach for task-related high-gamma modulation (HGM) in stereo-electroencephalography (SEEG) was developed and evaluated for language mapping.MethodsSEEG signals, acquired from drug-resistant epilepsy patients during a visual naming task, were analyzed to find clusters of 50–150 Hz power modulations in time–frequency domain. Classifier models to identify electrode contacts within the reference neuroanatomy and electrical stimulation mapping (ESM) speech/language sites were developed and validated.ResultsIn 21 patients (9 females), aged 4.8–21.2 years, SEEG HGM model predicted electrode locations within Neurosynth language parcels with high diagnostic odds ratio (DOR 10.9, p < 0.0001), high specificity (0.85), and fair sensitivity (0.66). Another SEEG HGM model classified ESM speech/language sites with significant DOR (5.0, p < 0.0001), high specificity (0.74), but insufficient sensitivity. Time to largest power change reliably localized electrodes within Neurosynth language parcels, while, time to center-of-mass power change identified ESM sites.ConclusionsSEEG HGM mapping can accurately localize neuroanatomic and ESM language sites.SignificancePredictive modelling incorporating time, frequency, and magnitude of power change is a useful methodology for task-related HGM, which offers insights into discrepancies between HGM language maps and neuroanatomy or ESM.     

Intraoperative MRI and FLAIR Analysis: Implications for low-grade glioma surgery

PurposeIntraoperative MRI (iMRI) offers the possibility of acquiring intraoperatively real-time images that will guide neurosurgeons when removing brain tumors. The objective of this study was to report the existence of FLAIR abnormalities on iMRI that may occur on the margin of a brain resection and may lead to misdiagnosis of residual tumor.MethodsWe retrospectively analyzed intraoperative MRI (iMRI) in 21 consecutive patients who underwent surgery for a low-grade glioma. Two readers independently reviewed iMRI images to search for the presence of a FLAIR hyperintensity surrounding the surgical cavity. For each patient, they were instructed to characterize FLAIR abnormalities on the margins of the resected area as (1) no FLAIR abnormality; (2) “linear FLAIR hyperintensity (LFH)”, when a < 5 mm linear FLAIR hyperintensity was present; or (3) “nodular FLAIR hyperintensity (NFH)”, in the case of a thick and nodular FLAIR hyperintensity.ResultsLFH were present on at least one surgical margin of one third of the patients analyzed with iMRI, and vanished on follow-up MRI, confirming its transient condition; whereas NFH were linked to persistence of pre-surgical abnormalities, such as residual tumor as confirmed or by histopathological analysis of a second surgery or by its remnant on follow-up MRI.ConclusionLinear FLAIR hyperintensities can be present on surgical margins analyzed by iMRI and should not be mistaken for residual tumor.     

Sarcolemmal depolarization in sporadic inclusion body myositis assessed with muscle velocity recovery cycles

ObjectiveTo study patients with sporadic inclusion body myositis (sIBM) with muscle velocity recovery cycles (MVRC) to assess muscle membrane excitability, pathophysiological mechanisms and potential biomarkers of this disorder.MethodsMVRC were recorded from 20 individuals with sIBM from tibialis anterior (TA) and rectus femoris (RF) muscles. Excitability parameters were compared with MVRC data obtained from 22 normal controls >50 years.ResultsMuscle relative refractory period was prolonged in both TA (6.4 ms vs 4.4 ms, P < 0.001) and RF (7.1 ms vs 3.9 ms, P < 0.001) of sIBM affected muscle when compared to controls. Early supernormality was reduced in both TA (3.6% vs 8.8% P = 0.001) and in RF (mean 5.4% vs 13% P < 0.001). Late supernormality was only decreased significantly in sIBM affected TA (1.8% vs 3.6% P = 0.001) but not in RF. No consistent correlations between MVRC parameters and clinical markers of sIBM disease severity were found.ConclusionThe resting sarcolemmal muscle membrane potential of sIBM muscle is depolarized relative to that of normal controls, which may be related to intramuscular amyloid deposition in sIBM.SignificanceSarcolemmal depolarization may play a role in muscle dysfunction and weakness observed in sIBM patients.     

Diagnostic efficacy and safety of gadoteridol compared to gadobutrol and gadoteric acid in a large sample of CNS MRI studies at 1.5 T

PurposeTo evaluate safety and diagnostic accuracy of gadoteridol vs. other macrocyclic gadolinium-based contrast agents (GBCAs) in a large cohort of consecutive and non-selected patients referred for CE-MRI of the CNS.Material and methodsBetween November 2017 and March 2018, we prospectively enrolled a consecutive cohort of patients referred for neuroradiological CE-MRI (1.5 T MRI). Image quality and adverse events were assessed. Diagnostic performance was determined for a subgroup of patients with truth standard findings available. Comparison was made between patients receiving gadoteridol and patients receiving other macrocyclic GBCAs. Inter-reader agreement (kappa) between two expert neuroradiologists was calculated for the diagnosis of malignancy.ResultsOverall, 460 patients (220 M/240F; mean age 54 ± 16 years) were enrolled of which 230 received gadoteridol (Group 1) and 230 either gadoteric acid or gadobutrol [n = 83 (36.1%) and n = 147 (63.9%), respectively; Group 2]. Image quality was rated as good or excellent in both groups. The sensitivity, specificity and diagnostic accuracy for determination of malignancy was 88.2%, 96.5% and 95.4%, respectively, for Group 1 and 93.7%, 97.4% and 96.9%, respectively, for Group 2, with no significant differences between groups (P > 0.75) for any determination. Inter-reader agreement for the identification of malignancy was excellent [K = 0.877 (95%CI: 0.758–0.995) and K = 0.818 (95%CI: 0.663–0.972) for groups 1 and 2, respectively; P = 0.0913]. Adverse events occurred in 5 of 460 (1.09%) patients overall, with no significant difference (P = 0.972) between groups.ConclusionGadoteridol was safe and guaranteed good image quality without significant differences when compared to gadobutrol and gadoteric acid in a wide range of CNS pathologies.     

Automated electrical source imaging with scalp EEG to define the insular irritative zone: Comparison with simultaneous intracranial EEG

Objective To evaluate the accuracy of automated interictal low-density electrical source imaging (LD-ESI) to define the insular irritative zone (IZ) by comparing the simultaneous interictal ESI localization with the SEEG interictal activity.Methods Long-term simultaneous scalp electroencephalography (EEG) and stereo-EEG (SEEG) with at least one depth electrode exploring the operculo-insular region(s) were analyzed. Automated interictal ESI was performed on the scalp EEG using standardized low-resolution brain electromagnetic tomography (sLORETA) and individual head models. A two-step analysis was performed: i) sublobar concordance between cluster-based ESI localization and SEEG-based IZ; ii) time-locked ESI-/SEEG analysis. Diagnostic accuracy values were calculated using SEEG as reference standard. Subgroup analysis was carried out, based on the involvement of insular contacts in the seizure onset and patterns of insular interictal activity.Results Thirty patients were included in the study. ESI showed an overall accuracy of 53% (C.I. 29–76%). Sensitivity and specificity were calculated as 53% (C.I. 29–76%), 55% (C.I. 23–83%) respectively. Higher accuracy was found in patients with frequent and dominant interictal insular spikes.Conclusions LD-ESI defines with good accuracy the insular implication in the IZ, which is not possible with classical interictal scalp EEG interpretation.SignificanceAutomated LD-ESI may be a valuable additional tool to characterize the epileptogenic zone in epilepsies with suspected insular involvement.     

Monitoring of patients with brainstem hemorrhage: A simultaneous study of quantitative electroencephalography and transcranial Doppler

ObjectiveTo explore whether quantitative electroencephalography (QEEG) and transcranial Doppler (TCD) can be used to evaluate patients with acute severe brainstem hemorrhage (ASBH).MethodsWe prospectively enrolled patients with ASBH and assessed their mortality at the 90-day follow-up. The patients' demographic data, serological data, and clinical factors were recorded. Quantitative brain function monitoring was performed using a TCD-QEEG recording system attached to the patient’s bedside.ResultsThirty-one patients (55.3 ± 10.6 years; 17 men) were studied. Mortality at 90 days was at 61.3%. There was no significant difference in TCD-related parameters between the survival group and the death group (p > 0.05). Among the QEEG-related indexes, only the (delta + theta)/(alpha + beta) ratio (DTABR) (odds ratio 11.555, 95%confidence interval 1.413–94.503, p = 0.022) was an independent predictor of clinical outcome; the area under the ROC curve of DTABR was 0.921, cut-off point was 3.88, sensitivity was 79%, and specificity was 100%.ConclusionsIn patients with ASBH, QEEG can effectively inform the clinical prognosis regarding 90-day mortality, while TCD cannot.SignificanceQEEG shows promise for informing the mortality prognosis of patients with ASBH.