Neuroradiology

Intracranial aneurysms in Sickle Cell Disease: Aneurysms characteristics and modalities of endovascular approach to treat these patients Publication date: Available online 20 March 2019 Source: Journal of Neuroradiology Author(s): Sophie Gallas, Titien Tuilier, Vahid Ebrahiminia, Pablo Bartoluci, Jérôme Hodel, André Gaston Abstract Introduction:The neurological complications of Sickle Cell Disease (SCD) include cerebral infarction and haemorrhage with rarely subarachnoid haemorrhage due to cerebral aneurysms. Materials and methods: In our interventional department, working with SCD referral department, we reported our experience concerning management of adult's patients with cerebral aneurysms. We identified 26 adults with 48 intracranial aneurysms documented by imaging. Results:18 patients, with 26 cerebral aneurysms were treated by endovascular approach for their aneurysms. No patient was treated by surgical way in our institution. 50% of patients had multiple aneurysms. Locations of aneurysms treated were typical with 70 % of cerebral anterior artery and 30 % of posterior artery. Three patients suffered from subarachnoid haemorrhage. Two procedure-related complications occurred during the treatment: one thrombo-embolic event with good recovery after medical treatment and one aneurismal perforation leading to the death of patient. Hypercoagulability is a major specific risk in SCD and use of permanent device as stent of flow diverter should be discussed to prevent complications. Conclusion: Endovascular management of these aneurysms seems to be a good alternative to treat these patients, with stability of occlusion at follow-up.

Safety and efficacy of balloon angioplasty in symptomatic intracranial stenosis: A systematic review and meta-analysis Publication date: Available online 9 March 2019 Source: Journal of Neuroradiology Author(s): Keisuke Kadooka, Niels Hagenbuch, Vania Anagnostakou, Anton Valavanis, Zsolt Kulcsár Abstract Background and purpose Endovascular treatment is offered for symptomatic intracranial stenosis (ICS) when medical therapy fails. The purpose of this meta-analysis is to evaluate the risks and effectiveness of balloon angioplasty (BA) alone. Materials and methods Systematic review and meta-analysis of all available articles on BA for symptomatic ICS was conducted. Data was analyzed separately for > 70% (Group 1) and > 50% (Group 2) stenosis. The results of the Group 1 were compared with those of SAMMPRIS study to the extent possible. Results A total of 25 studies comprising 674 patients were included. The cumulative incidence of periprocedural (within 30 days) stroke and death were 16.3% (Group 1), 7.6% (Group 2) and 11.5% (all studies). Incidence rates of ischemic stroke in the qualifying artery territory during follow-up (per 100 patient-years) were 2.0, 2.4 and 2.3, any stroke and death during follow-up were 4.4, 7.4 and 6.9, restenosis rates were 4.9, 11.5 and 8.9 respectively. While comparison of cumulative incidences of periprocedural ischemic stroke between Group 1 (13.0%) and the medical arm from SAMMPRIS study(4.4%) showed a significant difference (P = 0.008), there was no significant difference between the Group 1 and the stenting arm from SAMMPRIS study(10.7%) in the same variable. Conclusion Balloon angioplasty for stenosis of more than 70% is likely to have similar outcome comparable to the stenting arm in the SAMMPRIS study, however it presents lower rates of late ischemic events and restenosis. These data may help deciding on the endovascular method of choice in case of medical therapy failure.

Comparison of automated and visual DWI ASPECTS in acute ischemic stroke Publication date: Available online 9 March 2019 Source: Journal of Neuroradiology Author(s): E. Kellner, M. Reisert, V.G. Kiselev, C.J. Maurer, H. Urbach, K. Egger Abstract Background and purpose To assess intra-and inter-rater agreement of the ASPECTS (Alberta Stroke Program Early CT Score) based on diffusion-weighted MRI and to compare it with fully – automated methods (eASPECTS). Methods DWI-ASPECTS of scans of 96 patients with acute ischemic stroke was rated by 2 experts. Automated methods based on thresholding the affected volumes of a coregistered atlas, and a regression tree learning method were established. Intra-rater, inter-rater and human-rater vs. automated methods agreements were investigated based on the intraclass correlation coefficients (ICC) and Bland Altman plots. Results Intra-rater agreement was good for both raters (ICC of 0.91 and 0.93). Inter-rater agreement was worse (ICC = 0.86) indicating a slight bias between both raters. Agreement with automated methods ranged from 0.81 to 0.87. Root-mean-squared deviation was 0.89 and 0.69 for the human raters and ranged from 0.95 to 1.24 for the automated methods. Conclusions Agreement values are on the same order or higher compared to a literature review of CT-based ASPECTS. Automated methods perform slightly worse than human expert ratings, but they still have enough power to determine the DWI-ASPECTS with good precision in a clinical setting.

Comparative analysis of methods of volume adjustment in hippocampal volumetry for the diagnosis of Alzheimer disease Publication date: Available online 8 March 2019 Source: Journal of Neuroradiology Author(s): Susana Estévez-Santé, Adolfo Jiménez-Huete, for the ADNI group Abstract Introduction: Hippocampal volumetry can discriminate normal subjects from patients with amnestic mild cognitive impairment (MCI) or Alzheimer disease (AD). We have analyzed the effects of different methods of hippocampal volume (HV) adjustment on the diagnostic accuracy of this technique. Methods: Cross-sectional analysis of 148 subjects of the ADNI database (48 normal, 66 MCI, 34 AD). Brain volumes were calculated from 3T MRI scans with gm extractor, a fully automated script based on FSL. A series of logistic regression models was obtained using 9 volumes of reference and 3 methods of adjustment (normalization, covariance, bilinear regression). Diagnostic accuracy was evaluated with the receiver operating characteristic curve method. External validity was assessed with 10-fold cross-validation. Results: The models with the highest area under the curve (AUC) were those including the HV normalized by total intracranial volume (TIV). The differences with bilinear regression and the covariance method adjusted by TIV were minor and not statistically significant. The lowest AUCs corresponded to the models based on raw (unadjusted) HVs. The results were qualitatively similar in two clinical settings (normal versus MCI, and normal versus AD), but the differences were higher in the normal versus MCI context. Conclusion: The accuracy of hippocampal volumetry for the differential diagnosis between normal subjects and patients with MCI or AD was maximized by normalizing the HV by the TIV. Our results do not exclude the potential superiority of non-linear models.

Impact of aneurysm morphology on safety and effectiveness of flow diverter treatment of vertebrobasilar aneurysms Publication date: Available online 8 March 2019 Source: Journal of Neuroradiology Author(s): Adam N. Wallace, Travis S. CreveCoeur, Jonathan A. Grossberg, Mudassar Kamran, Joshua W. Osbun, Josser E. Delgado Almandoz, DeWitte T. Cross, Christopher J. Moran

Cerebral amyloidoma: A mimicker of granulomatous disease on brain MRI Publication date: Available online 7 March 2019 Source: Journal of Neuroradiology Author(s): Alireza Radmanesh, Matthew D. Wood, Andrew W. Bollen

Congenital Zika syndrome and cerebellar cortical problem Publication date: Available online 7 March 2019 Source: Journal of Neuroradiology Author(s): Beuy Joob, Viroj Wiwanitkit

Improved detection and characterization of arterial occlusion in acute ischemic stroke using contrast enhanced MRA Publication date: Available online 7 March 2019 Source: Journal of Neuroradiology Author(s): Sarah Dhundass, Julien Savatovsky, Loïc Duron, R. Fahed, Simon Escalard, Michael Obadia, Kevin Zuber, Marie Astrid Metten, Mehdi Mejdoubi, Raphaël Blanc, Jean-Claude Sadik, Adrien Collin, Augustin Lecler Abstract Background and purpose To compare the accuracy and utility of contrast enhanced magnetic resonance angiography (MRA) (CEMRA) to Time of Flight MRA (TOF MRA) during detection and evaluation of occlusions on patients diagnosed with acute ischemic stroke (AIS). Methods This single-center study was approved by our local institutional research ethics board. From August 2014 to July 2016, 131 consecutive adult patients with confirmed AIS were included. Detection of an arterial occlusion and its characterization were evaluated independently with CEMRA or TOF MRA by two blinded neuroradiologists, then by consensus using all available MR sequences. A Cohen's Kappa coefficient (κ) and intra-class correlation coefficients (ICC) were used to compare the two techniques. Results There was substantial concordance in the detection of arterial occlusion between CEMRA and TOF MRA (κ = 0.75). TOF MRA was more likely to show an arterial occlusion than CEMRA (63 versus 52 patients respectively). There were 13 and 1 false positive arterial occlusion with TOF MRA and CEMRA respectively, and 1 false negative with TOF MRA. There was excellent concordance between the location of arterial occlusions and CEMRA and TOF MRA [κ = 0.89 (0.72–0.97)]. CEMRA was significantly more likely to allow measurement of the thrombus than was TOF MRA [38 (75%) versus 14 (22%)] (P < 0.0001). Conclusions Our study showed that CEMRA imaging detected arterial occlusions better than TOF MRA in AIS patients and more precisely such that thrombus length and location could be known, which improves the patient's management and care.

Review of synthetic MRI in pediatric brains: Basic principle of MR quantification, its features, clinical applications, and limitations Publication date: Available online 7 March 2019 Source: Journal of Neuroradiology Author(s): Christina Andica, Akifumi Hagiwara, Masaaki Hori, Koji Kamagata, Saori Koshino, Tomoko Maekawa, Michimasa Suzuki, Hirokazu Fujiwara, Mitsuru Ikeno, Toshiaki Shimizu, Hiroharu Suzuki, Hidenori Sugano, Hajime Arai, Shigeki Aoki Abstract 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.

Quantitative evaluation of WEB shape modification: A five-year follow-up study Publication date: Available online 7 March 2019 Source: Journal of Neuroradiology Author(s): Kevin Janot, Denis Herbreteau, Aymeric Amelot, Guillaume Charbonnier, Fakhreddine Boustia, Ana Paula Narata, Basile Kerleroux, Richard Bibi, Chrysanthi Papagiannaki, Aymeric Rouchaud, Laurent Pierot Abstract Background and purpose Web shape modification (WSM) has previously been associated with aneurysm recurrence. We report here our five-year experience of WEB device use with a quantitative approach of the WSM phenomenon. Methods From July 2012 to July 2017, 50 patients with 51 unruptured aneurysms treated with the WEB device have been prospectively enrolled in our data base and retrospectively analyzed. An independent "core lab" evaluated anatomical results and potential WSM in DSA follow-up. We defined the WSM ratio (WSMr) as a relative index between the height and the width of the device in working projections which gave an evaluation of the device deformation over the time. Results During the total follow-up period, WSM was observed in 35/48 aneurysms (72.9%). Adequate occlusion rates were 87.0% and 92.6% with and without WSM respectively (P = 0.65). 30 out the 35 (85.7%) shape modifications were already noticed at short-term follow-up (6-month DSA). 33 patients had 2 DSA controls and WSMr measurements were available in 24 patients: 18 (75%) with WSM and 6 (25%) without WSM. In the group with WSM, WSMr values were 0.80 in post-embolization, 0.52 at the first DSA angiogram and 0.42 at the second DSA angiogram. Conclusion WEB shape modification was observed in more than half of cases but with no influence regarding adequate occlusion rate. This quantitative approach of WSM highlights that this phenomenon appears to be early and progressive over time. This supports the hypothesis that WSM could be more probably related to aneurysm healing rather than external compression.