Clinical Neuroradiology

Performance of a Deep-Learning Neural Network to Detect Intracranial Aneurysms from 3D TOF-MRA Compared to Human Readers Abstract Purpose To study the clinical potential of a deep learning neural network (convolutional neural networks [CNN]) as a supportive tool for detection of intracranial aneurysms from 3D time-of-flight magnetic resonance angiography (TOF-MRA) by comparing the diagnostic performance to that of human readers. Methods In this retrospective study a pipeline for detection of intracranial aneurysms from clinical TOF-MRA was established based on the framework DeepMedic. Datasets of 85 consecutive patients served as ground truth and were used to train and evaluate the model. The ground truth without annotation was presented to two blinded human readers with different levels of experience in diagnostic neuroradiology (reader 1: 2 years, reader 2: 12 years). Diagnostic performance of human readers and the CNN was studied and compared using the χ2-test and Fishers' exact test. Results Ground truth consisted of 115 aneurysms with a mean diameter of 7 mm (range: 2–37 mm). Aneurysms were categorized as small (S; <3 mm; N = 13), medium (M; 3–7 mm; N = 57), and large (L; >7 mm; N = 45) based on the diameter. No statistically significant differences in terms of overall sensitivity (OS) were observed between the CNN and both of the human readers (reader 1 vs. CNN, P = 0.141; reader 2 vs. CNN, P = 0.231). The OS of both human readers was improved by combination of each readers' individual detections with the detections of the CNN (reader 1: 98% vs. 95%, P = 0.280; reader 2: 97% vs. 94%, P = 0.333). Conclusion A CNN is able to detect intracranial aneurysms from clinical TOF-MRA data with a sensitivity comparable to that of expert radiologists and may have the potential to improve detection rates of incidental findings in a clinical setting.

Effect of MRI-based semiautomatic size-assessment in cerebral metastases on the RANO-BM classification Abstract Aim Evaluation of a semiautomatic software algorithm for magnetic resonance imaging (MRI)-based assessment of cerebral metastases in cancer patients. Material and Methods Brain metastases (n = 131) in 38 patients, assessed by contrast-enhanced MRI, were retrospectively evaluated at two timepoints (baseline, follow-up) by two experienced neuroradiologists in a blinded manner. The response assessment in neuro-oncology (RANO) criteria for brain metastases (RANO-BM) were applied by means of a software (autoRANO-BM) as well as manually (manRANO-BM) at an interval of 3 weeks. Results The average diameter of metastases was 12.03 mm (SD ± 6.66 mm) for manRANO-BM and 13.97 mm (SD ± 7.76 mm) for autoRANO-BM. Diameter figures were higher when using semiautomatic measurements (median = 11.8 mm) as compared to the manual ones (median = 10.2 mm; p = 0.000). Correlation coefficients for intra-observer variability were 0.993 (autoRANO-BM) and 0.979 (manRANO-BM). The interobserver variability (R1/R2) was 0.936/0.965 for manRANO-BM and 0.989/0.998 for autoRANO-BM. A total of 19 lesions (15%) were classified differently when using semiautomatic measurements. In 14 cases with suspected disease progression by manRANO-BM a stable course was found according to autoRANO-BM. Conclusion Computerized measuring techniques can aid in the assessment of cerebral metastases by reducing examiner-dependent effects and may consequently result in a different classification according to RANO-BM criteria.

Effectiveness of Revive SE in the RAPID registry Abstract Purpose The prospective, multicenter Revive Acute ischemic stroke Patients ImmeDiately (RAPID) trial was carried out to evaluate the real-world safety and efficacy of the Revive SE stent retriever. Methods From January 2017 the study planned to enroll 100 patients with acute ischemic stroke who were treated with the Revive SE as a first pass. The study primary outcomes were rates of favorable reperfusion using the modified thrombolysis in cerebral infarction score [mTICI] 2b/3 and rates of favorable outcome with the modified Rankin Scale (mRS) ≤2 at 3 months. The secondary outcomes were time interval from puncture to vascular reperfusion, number of passes by Revive SE stent-retriever, incidence of distal embolization and into new territories and rate of symptomatic intracranial hemorrhage (SICH) within 24 h post intervention. Results A total of 100 treated patients (mean age: 65.6 ± 11.3 years) were enrolled. The median National Institutes of Health Stroke Scale before the procedure was 16. Target vessel occlusions were as follows: middle cerebral artery (MCA) M1 in 48, M2 in 6, anterior cerebral artery (ACA) in 3, internal carotid artery (ICA) in 22, basilar artery (BA) in 17, and vertebral artery (VA) in 4. Reperfusion rate with Revive SE without rescue devices was 69%. Reperfusion rate with Revive SE only was 83.3% in MCA M2, followed by 82.4% in BA. Thromboembolic complications and SICH developed in 10% and 2% of patients, respectively. Overall, a satisfactory reperfusion was achieved in 92% and a favorable outcome at 90 days in 48%. Conclusion Use of the Revive SE for thrombectomy appeared to be effective and safe but these findings need be confirmed in larger clinical trials (RAPID ClinicalTrials.gov number, NCT03007082).

Microstructural White Matter Alterations in Mild Cognitive Impairment and Alzheimer's Disease Abstract Purpose To investigate microstructural alterations in white matter in mild cognitive impairment (MCI) and Alzheimer's disease (AD) using neurite orientation dispersion and density imaging (NODDI) and to assess the potential diagnostic performance of NODDI-derived parameters. Methods In this study 14 MCI patients, 14 AD patients, and 14 healthy controls (HC) were recruited. The diffusion tensor imaging(DTI)-derived fractional anisotropy (FA) and NODDI-derived neurite density index (NDI), orientation dispersion index (ODI), and volume fraction of isotropic water molecules (Viso) were calculated from the diffusion data. The tract-based spatial statistics (TBSS) method was used for statistical analysis with one-way ANOVA. The correlations between the parameter values and mini-mental state examination (MMSE) and Montreal cognitive assessment (MoCA) scores were examined. A receiver operating characteristic (ROC) curve was conducted to assess the diagnostic performance of different parameters. Results Compared with the HC group, the NDI and ODI values decreased significantly and the Viso values were significantly increased in the MCI and AD groups (p < 0.01, threshold-free cluster enhancement (TFCE)-corrected); however, there were no significant differences in FA values in the MCI group. The NDI, ODI, and Viso values of multiple fibers were significantly correlated with MMSE and MoCA scores. For the diagnosis of AD, the area under the ROC curve (AUC) for the NDI value of the splenium of corpus callosum was larger than the FA value (AUC = 0.885, 0.714, p = 0.042). The AUC of the Viso value of the right cerebral peduncle was larger than FA value (AUC = 0.934, 0.531, p = 0.004). Conclusion The NDI is more sensitive to white matter microstructural changes than FA and NODDI could be superior to DTI in the diagnosis of AD.

Aggregometry Response to Half-dose Prasugrel in Flow-diverting Stent Implantation Abstract Purpose The aim of this study was to determine whether half-dose loading (30 mg) of prasugrel is sufficient to achieve adequate platelet inhibition, and whether such a loading dose of prasugrel together with aspirin followed by a 10 mg/day prasugrel maintenance, could serve as a first-line antiplatelet strategy for patients undergoing flow-diverting stent (FDS) implantation. Methods Data from a group of consecutive patients treated for intracranial aneurysm with FDS were retrospectively collected. Platelet P2Y12 receptor responsiveness was assessed by a rapid platelet function test just prior to the procedure. All ischemic and hemorrhagic complications as well as morbidity and mortality rates were documented. Results A total of 138 patients with 153 aneurysms (32 were symptomatic and 121 were incidental) underwent FDS treatment in a total of 147 loading sessions. Adequate platelet inhibition was obtained in 136/138 (98.5%) patients and 145/147 (98.6%) loading sessions. Overall, there was one case of (hemorrhagic) mortality (0.7%), one of (ischemic) morbidity (0.7%), one of symptomatic (hemorrhagic) clinical complications without permanent deficits (0.7%), and six transient ischemic attacks (4.1%). The 6‑month control angiography, available for all patients, revealed a 95.4% aneurysm occlusion rate. Conclusion Half-dose (30 mg) prasugrel loading results in effective platelet P2Y12 receptor inhibition in more than 98% of patients. Dual antiaggregant loading with half dose prasugrel followed by prasugrel maintenance as a first-line therapy appears to be feasible in patients treated with FDS implantation for intracranial aneurysm.

Correction to: Accuracy and Reliability of Multiphase CTA Perfusion for Identifying Ischemic Core Correction to: Clin Neuroradiol 2018 https://doi.org/10.1007/s00062-018-0717-x Unfortunately, the author list of the original version of this article contains a mistake. The middle name of the author "Rani Gupta Sah" was erroneously tagged as part of the surname in the article's metadata. This mistake

Clinical Characteristics and Outcome of Patients with Lacunar Infarcts and Concurrent Embolic Ischemic Lesions Abstract Purpose Lacunar infarcts are thought to result from occlusion of small penetrating arteries due to microatheroma and lipohyalinosis, pathognomonic for cerebral small vessel disease (CSVD). Concurrent embolic ischemic lesions indicate a different stroke mechanism. The purpose of this study was to examine the clinical characteristics and outcome of patients with lacunar infarcts and concurrent embolic infarcts on diffusion-weighted imaging (DWI). Methods All patients screened for the WAKE-UP trial (ClinicalTrials.gov number, NCT01525290) were reviewed for acute lacunar infarcts and concurrent embolic lesions on baseline DWI. Clinical characteristics and outcome were compared between lacunar infarct patients with and without concurrent embolic lesions. Results Of 244 patients with an acute lacunar infarct, 20 (8.2%) had concurrent acute embolic infarcts. Compared to patients with a lacunar infarct only, patients with concurrent embolic infarcts were older (mean age 69 years vs. 63 years; p = 0.031), more severely affected (median National Institutes of Health Stroke Scale [NIHSS] score 5 vs. 4; p = 0.046), and—among those randomized—had worse functional outcome at 90 days (median modified Rankin Scale [mRS] 3 vs. 1; p = 0.011). Conclusion Approximately 8% of lacunar infarct patients show concurrent embolic lesions suggesting a stroke etiology other than CSVD. These patients are more severely affected and have a worse functional outcome illustrating the need for a thorough diagnostic work-up of possible embolic sources even in patients with an imaging-defined diagnosis of lacunar infarcts.

Correction to: Cranial MR-guided Focused Ultrasound for Essential Tremor Correction to: Clin Neuroradiol 2018 https://doi.org/10.1007/s00062-018-0709-x The original version of this article unfortunately contained a mistake. The tagging of the name J. Levi Chazen was incorrect. The correct information is given …

Future Neuroradiology

Lateral rectus atrophy in cavernous sinus thrombosis

Alexandros Sfakianakis
Anapafseos 5 . Agios Nikolaos
Crete.Greece.72100
2841026182

6948891480

alsfakia@gmail.com