Neuroradiology

European Society of Neuroradiology (ESNR)

Exploring new landmarks: analysis of Twitter usage during the 41st ESNR Annual Meeting Abstract We analyzed the use of Twitter during the 41st Annual Meeting of the European Society of Neuroradiology (ESNR) held in Rotterdam from 19 to 23 September 2018. The aim was to check the status of the European neuroradiology Twitter community and to discover which topics were discussed most often. The data were compared with a similar analysis performed during the Annual Meeting of the American Society of Neuroradiology (ASNR) in 2014. Even though the analysis demonstrated a low use of Twitter during the ESNR meeting, the platform still generated an important volume of impressions and engagement. This use was noted by the global community because topics of the meeting, such as the value of radiological reporting and advanced imaging, were discussed worldwide. These data, also compared to the American meeting, suggests a need for more prolific use and engagement with ESNR social media accounts in order to draw our members into discussions during meetings and to reinforce the place of European neuroradiology in the debate on key imaging topics as well as promoting society events.

Altered coupling of spontaneous brain activities and brain temperature in patients with adolescent-onset, first-episode, drug-naïve schizophrenia Abstract Purpose A recent study has reported that schizophrenia patients show an uncoupled association between intraventricular brain temperature (BT) and cerebral blood flow (CBF). CBF has been found to be closely coupled with spontaneous brain activities (SBAs) derived from resting-state BOLD fMRI metrics. Yet, it is unclear so far whether the relationship between the intraventricular BT and the SBAs may change in patients with adolescent-onset schizophrenia (AOS) compared with that in healthy controls (HCs). Methods The present study recruited 28 first-episode, drug-naïve AOS patients and 22 matched HCs. We measured the temperature of the lateral ventricles (LV) using diffusion-weighted imaging thermometry and measured SBAs using both regional homogeneity and amplitude of low-frequency fluctuation methods. A nonparametric Wilcoxon rank sum test was used to detect the difference in intraventricular BT between AOS patients and HCs with LV volume, age, and sex as covariates. We also evaluated the relationship between the intraventricular BT and the SBAs using partial correlation analysis controlling for LV volume, age, and sex. Results We found that HCs showed a significant negative correlation between the intraventricular BT and the local SBAs in the bilateral putamina and left superior temporal gyrus, while such a correlation was absent in AOS patients. Additionally, no significant difference between the two groups was found in the intraventricular BT. Conclusion These findings suggest that AOS patients may experience an uncoupling between intraventricular BT and SBAs in several schizophrenia-related brain areas, which may be associated with the altered relationships among intraventricular BT, CBF, and metabolism.

Atrophy of the ipsilateral mammillary body in unilateral hippocampal sclerosis shown by thin-slice-reconstructed volumetric analysis Abstract Purpose Conventional volumetric analysis could not detect ipsilateral atrophy of the mammillary body in patients with unilateral hippocampal sclerosis. By using thin-slice-reconstructed volumetric analysis, we investigated whether the mammillary body volume is smaller on the hippocampal sclerosis side than in healthy subjects or the non-hippocampal sclerosis side. Methods This retrospective study included 45 patients with unilateral hippocampal sclerosis and 30 healthy subjects. Three-dimensional T1WI of 1 mm thicknesses were oversampled to a thickness of 0.2 mm (thin-slice-reconstructed images), and the mammillary bodies were segmented manually to determine mammillary body volume on each side. Mammillary body volumes on the hippocampal sclerosis side were compared with those in healthy subjects or the non-hippocampal sclerosis side. Results In patients with right hippocampal sclerosis, right mammillary body volume was both significantly smaller than that in healthy subjects (30.3 ± 10.3 vs. 43.3 ± 8.07 mm3, P < 0.001) and significantly smaller than the left mammillary body volume in each patient (30.3 ± 10.3 vs. 41.4 ± 10.1 mm3, P < 0.001). Similarly, in patients with left hippocampal sclerosis, left mammillary body volume was both significantly smaller than that in healthy subjects (37.7 ± 11.2 vs. 47.0 ± 8.65 mm3, P < 0.001) and significantly smaller than right mammillary body volume in each patient (37.7 ± 11.2 vs. 42.5 ± 7.78 mm3, P = 0.044). Conclusions In this study, thin-slice-reconstructed volumetric analysis showed that, in patients with unilateral hippocampal sclerosis, mammillary body volume on the hippocampal sclerosis side is smaller than that in healthy subjects and the non-hippocampal sclerosis side.

Evaluation of 3D fat-navigator based retrospective motion correction in the clinical setting of patients with brain tumors Abstract Purpose A 3D fat-navigator (3D FatNavs)-based retrospective motion correction is an elegant approach to correct for motion as it requires no additional hardware and can be acquired during existing 'dead-time' within common 3D protocols. The purpose of this study was to clinically evaluate 3D FatNavs in the work-up of brain tumors. Methods An MRI-based fat-excitation motion navigator incorporated into a standard MPRAGE sequence was acquired in 40 consecutive patients with (or with suspected) brain tumors, pre and post-Gadolinium injection. Each case was categorized into key anatomical landmarks, the temporal lobes, the infra-tentorial region, the basal ganglia, the bifurcations of the middle cerebral artery, and the A2 segment of the anterior cerebral artery. First, the severity of motion in the non-corrected MPRAGE was assessed for each landmark, using a 5-point score from 0 (no artifacts) to 4 (non-diagnostic). Second, the improvement in image quality in each pair and for each landmark was assessed blindly using a 4-point score from 0 (identical) to 3 (strong correction). Results The mean image improvement score throughout the datasets was 0.54. Uncorrected cases with light and no artifacts displayed scores of 0.50 and 0.13, respectively, while cases with moderate artifacts, severe artifacts, and non-diagnostic image quality revealed a mean score of 1.17, 2.25, and 1.38, respectively. Conclusion Fat-navigator-based retrospective motion correction significantly improved MPRAGE image quality in restless patients during MRI acquisition. There was no loss of image quality in patients with little or no motion, and improvements were consistent in patients who moved more.

An integrated in utero MR method for assessing structural brain abnormalities and measuring intracranial volumes in fetuses with congenital heart disease: results of a prospective case-control feasibility study Abstract Purpose To refine methods that assess structural brain abnormalities and calculate intracranial volumes in fetuses with congenital heart diseases (CHD) using in utero MR (iuMR) imaging. Our secondary objective was to assess the prevalence of brain abnormalities in this high-risk cohort and compare the brain volumes with normative values. Methods We performed iuMR on 16 pregnant women carrying a fetus with CHD and gestational age ≥ 28-week gestation and no brain abnormality on ultrasonography. All cases had fetal echocardiography by a pediatric cardiologist. Structural brain abnormalities on iuMR were recorded. Intracranial volumes were made from 3D FIESTA acquisitions following manual segmentation and the use of 3D Slicer software and were compared with normal fetuses. Z scores were calculated, and regression analyses were performed to look for differences between the normal and CHD fetuses. Results Successful 2D and 3D volume imaging was obtained in all 16 cases within a 30-min scan. Despite normal ultrasonography, 5/16 fetuses (31%) had structural brain abnormalities detected by iuMR (3 with ventriculomegaly, 2 with vermian hypoplasia). Brain volume, extra-axial volume, and total intracranial volume were statistically significantly reduced, while ventricular volumes were increased in the CHD cohort. Conclusion We have shown that it is possible to perform detailed 2D and 3D studies using iuMR that allow thorough investigation of all intracranial compartments in fetuses with CHD in a clinically appropriate scan time. Those fetuses have a high risk of structural brain abnormalities and smaller brain volumes even when brain ultrasonography is normal.

Radiation exposure of image-guided intrathecal administration of nusinersen to adult patients with spinal muscular atrophy Abstract Purpose To examine diagnostic reference levels (DRL) and achievable doses (AD) of image-guided and size-specific dose estimates (SSDE) and organ and effective doses of CT-guided intrathecal nusinersen administration to adult patients with spinal muscular atrophy (SMA). Methods This study involved a total of 60 image-guided intrathecal nusinersen treatments between August 2017 and June 2018. Patient cohort comprised 14 adult patients with the following SMA types: type 2 (n = 9) and type 3 (n = 5) with a mean age of 33.6 years (age range 25–57 years). DRL, AD, SSDE, organ, and effective doses were assessed with a dose-monitoring program based on the Monte Carlo simulation techniques. Results DRL and AD for computed tomography are summarised as follows: in terms of CT-dose index (CTDIvol), DRL 56.4 mGy and AD 36.7 mGy; in terms of dose-length product (DLP), DRL 233.1 mGy cm and AD 120.1 mGy cm. DRL and AD for fluoroscopic guidance were distributed as follows: in terms of dose-area product (DAP), DRL 239.1 μGy m2 and AD 135.2 mGy cm2. Mean SSDE was 9.2 mGy. Mean effective dose of the CT-guided injections was 2.5 mSv (median 2.0 mSv, IQR 1.3–3.2 mSv). Highest organ doses in the primary beam of radiation were the small intestine 12.9 mSv, large intestine 9.5 mSv, and ovaries 3.6 mSv. Conclusion Radiation exposure of SMA patients measured as DRLs is generally not higher compared with patients without SMA despite severe anatomical hazards. Dose monitoring data may allow clinicians to stratify radiation risk, identify organs at risk, and adopt measures for specific radiation dose reduction.

Gadolinium retention in gliomas and adjacent normal brain tissue: association with tumor contrast enhancement and linear/macrocyclic agents Abstract Purpose To quantitate gadolinium deposits in gliomas and adjacent normal brain specimens, and to evaluate their association with tumor contrast enhancement and the type of gadolinium-based contrast agent (GBCA) used. Methods A total of 69 patients with primary glioma who underwent contrast-enhanced magnetic resonance imaging (MRI) prior to surgery were included in this retrospective study. Gadolinium was measured from histologically viable tumor, normal brain, and necrosis within the sample, when available, using inductively coupled plasma mass spectrometry (ICP-MS). Tumor contrast enhancement was categorized as none, minimal, or noticeable. Differences in gadolinium deposits by contrast enhancement and GBCA type were assessed. Results Seven patients received linear GBCA and 62 macrocyclic, respectively. At the time of surgery, gadolinium deposits were detected in 39 out of 69 (57%) tumor samples, 8 out of 13 (62%) normal brain, and 12 out of 14 (86%) necrotic specimens. Gadolinium was detected in both enhancing and non-enhancing tumors, but was greatest in gliomas with noticeable enhancement (p = 0.02). Administration of linear agents gadodiamide and gadopentetate dimeglumine resulted in significantly higher tumor gadolinium relative to macrocyclic gadoterate meglumine (p < 0.01 and p < 0.05, respectively). Normal brain and necrosis also showed higher gadolinium after exposure to linear gadodiamide (both p < 0.05). In multivariate regression, GBCA type (linear/macrocyclic) was the most powerful predictor of tumor gadolinium retention (p < 0.001). Conclusion Gadolinium can be detected in both enhancing and non-enhancing gliomas, neighboring normal brain, and necrosis. Gadolinium retention is higher after exposure to linear GBCAs compared with the macrocyclic gadoterate meglumine.

Grey matter activation by caloric stimulation in patients with unilateral peripheral vestibular hypofunction Abstract Purpose A combination of the caloric test with functional magnetic resonance imaging (fMRI) is a promising method for a comprehensive diagnostics of pathologies of the vestibular system. The aim of this study was to investigate the potential pattern of grey matter local activation in fMRI using cold and hot caloric stimulation in patients presenting unilateral peripheral vestibular injury. Methods Forty right-handed participants aged 27 to 56 with the diagnosis of right-sided peripheral vestibular hypofunction were included. Stimulation was performed separately for the right and the left ear with cold (C, 14–15 °C) stimulus and hot (H, 48–49 °C) stimulus. Grey matter activation was assessed in BOLD technique using a 3T scanner. Results We observed activity within the parieto-insular vestibular cortex (PIVC), thalamus, insula and retroinsular area, hippocampus, and cerebellum, as well as oculomotor centers located in the precentral gyrus, superior temporal gyrus, and intraparietal sulcus. Cold stimulus resulted in more areas of activation in response to the right ear activation rather than to the left ear. The ipsilateral activity was noted for insular cortex and intraparietal sulcus. The differences between hot and cold stimuli were noted for the right ear. Conclusions In this preliminary study, the combination of the caloric test and fMRI allowed to present specific pattern of grey matter activation in patients with unilateral peripheral vestibular injury. Further studies are necessary to develop patterns or cortical maps differentiating various balance disorders and to analyze the dynamics of cortical plasticity after the injury.

Asymmetric cavernous sinus enlargement: a novel finding in Sturge–Weber syndrome Abstract Purpose Enlargement of deep cerebral veins and choroid plexus engorgement are frequently reported in Sturge–Weber syndrome. We aim to describe cavernous sinus involvement in patients with this syndrome and to identify possible clinical-neuroimaging correlations. Methods Sixty patients with Sturge–Weber syndrome (31 females, mean age 4.5 years) and 120 age/sex-matched controls were included in this retrospective study. We performed a visual analysis to identify patients with asymmetric cavernous sinus enlargement. Then, we measured on axial T2WI the left (A), right (B), and bilateral (LL) transverse diameters of the cavernous sinus. We calculated the module of the difference |A-B| and the cavernous sinus asymmetry index as the ratio |A-B|/LL. Differences among groups were assessed by Mann–Whitney U and Kruskal–Wallis tests. Clinicoradiological associations were evaluated by Fisher exact test. Results We found seven subjects (11.6%) with asymmetric CS enlargement. The |A-B| and cavernous sinus asymmetry index were higher in patients with asymmetric CS enlargement compared with controls and patients without visible CS abnormalities (pB < 0.05). Asymmetric CS enlargement was always ipsilateral to facial port-wine stains (7/7), and, when present, to leptomeningeal vascular malformations (4/7). It was significantly associated with ipsilateral bone marrow changes (p = 0.013) and dilated veins (p = 0.002). Together with brain atrophy and deep venous dilatation, this sign was associated with neurological deficits (p < 0.05). Conclusions We expanded the spectrum of venous abnormalities in SWS, showing the presence of asymmetric cavernous sinus enlargement in more than one tenth of patients, likely related to increased venous drainage.