Mechanical thrombectomy for middle cerebral artery M2 occlusions.

BACKGROUND: The safety and efficacy of mechanical thrombectomy (MT) for proximal large vessel occlusion after acute ischemic stroke (AIS) have been demonstrated. Clinical investigations of endovascular approaches for treating AIS due to M2 occlusions have been ongoing. PURPOSE: To assess the outcomes of M2 occlusions according to treatment modality and anatomical division. METHODS: A total of 113 consecutive M2 occlusions treated with endovascular treatment (EVT) at our tertiary stroke center between January 2019 and December 2022 were retrospectively analyzed. Patients were divided into three groups: mechanical thrombectomy (MT); intravenous thrombolysis plus MT (IVT + MT); and IVT alone. The primary outcomes were good prognosis (mRS = 0-2) and mortality (mRS = 6) on day 90. The secondary outcome was to determine the differences in outcomes between lesions in the superior and inferior branches of M2. RESULTS: In total, 55 (48.7%) patients underwent MT. In 42 (37.2%) patients, bridging IVT was performed with MT, and IVT alone was applied in 16 (14.2%) patients. Neither the prognosis at 90 days nor the mortality rate significantly differed among the groups. The outcomes did not significantly differ between occlusions in the superior and inferior branches of M2. CONCLUSION: MT was found to be safe and effective for treating M2 occlusions in this series.

Points to consider when evaluating three-dimensional digital subtraction angiography of intracranial aneurysms and their effects on treatment

Background/aim: In this study, we aimed to investigate what should be regarded as potential determinants of treatment strategies when evaluating 3D digital subtraction angiography (DSA) images. Material and methods: Our inclusion criteria were as follows: (1) presence of at least one intracranial aneurysm demonstrated by conventional angiography, (2) having both 2D and 3D images, and (3) being over 18 years old. First, two-dimensional (2D) and then 3D angiography images of 226 aneurysms of 150 patients were scanned. Morphological characteristics such as size, configurations, relationship with parent artery, baby counts, and other incidental findings were determined. Results: Of the 226 aneurysms, 11 (4.9%) were only detected on 3D images. Four of these 11 additional aneurysms were believed to be babies of other aneurysms seen in 2D images. Middle cerebral artery (MCA) M1 segment was the most common localization in terms of missed aneurysms. Of the 28 aneurysms located in the communicating segment of the internal carotid artery, the absolute locations of 7 (25%) could not be detected in 2D images or detected in the wrong location. Of the 24 aneurysms located in the ophthalmic segment, the origin of 8 (33%) could not be clearly identified in 2D images. Truncus relationships of MCAs bifurcation/trifurcation aneurysms were seen in 41 of 63 aneurysms (65%) on 2D images, whereas all were confirmed on 3D images. Fenestrations not seen in 2D images were identified in 3D images of 4 patients (3%). Conclusion: The superiority of 3D images compared to 2D images in determining the morphologic characteristics of intracranial aneurysms has been known for a long time. The contribution of 3D images to the treatment can be summarized as evaluating the parent artery relationship, revealing the number and shapes of aneurysm babies more clearly, detecting fenestrations, and shortening procedure time by finding the correct working angle.

Effects of Obstructive Carotid Artery Disease on Ocular Circulation and the Safety of Carotid Artery Stenting.

BACKGROUND: The aims of this study were to examine the ophthalmic artery flow changes in patients with obstructive carotid artery disease, evaluate the orbital blood flow changes after carotid artery stenting and assess the safety of carotid stenting procedure by using transorbital colour and spectral Doppler sonography. METHODS: Thirty-one consecutive patients scheduled for carotid stenting with severe internal carotid artery stenosis (>60%; the study group) and 30 control subjects were included. Ophthalmic artery (OA) Doppler sonography was performed in the control group and study group before and after stenting. Peak systolic velocity (PSV), end-diastolic velocity (EDV), pulsatility index (PI), and resistive index (RI) and systolic/diastolic ratio (S/D) in the ophthalmic artery were recorded. Statistical comparisons were made between controls and study group before stenting and before and after stenting in the study group. RESULTS: Comparison between control and study group before stenting revealed a statistically significant decrease in OA PSV (51.5±14.5 vs. 39.7±19cm/sec, p= 0.008) and EDV (15.2±4.5 vs. 11.3±5.7cm/sec, p=0.004) in the study group. Differences in PI (1.3±0.14 vs. 1.36±0.4, p=0.47), RI (0.7±0.04 vs. 0.75±0.21, p=0.19), and S/D (3.5±0.6 vs. 3.6±1, p= 0.5) ratio were not statistically significant between groups. Peak systolic velocity (39.7±18.9 vs. 51.3±22.2cm/sec, p <0.001), RI (0.75±0.21 vs. 0.81±0.13, p=0.16) and S/D ratio (3.6±1 vs. 4.6±1.5, p= 0.001) were found to be significantly increased in the study group after stenting compared to baseline. There were no statistically significant differences in EDV and RI EDV(11.3±5.7 vs. 11.7±5.7cm/sec, p=0.66), PI (1.36±0.4 vs. 1.6±0.6, p =0.047) after stenting. CONCLUSIONS: Ophthalmic artery flow parameters were significantly lower in patients with severe carotid artery stenosis compared to control, indicating compromised ocular blood flow in severe carotid stenosis. Flow indicators significantly improved after stent implantation suggesting the importance of revascularisation in restoring ocular blood flow and safety of carotid stenting.

Stent plus balloon-assisted coiling with low-profile braided stents in the treatment of complex wide-necked intracranial bifurcation aneurysms.

INTRODUCTION: Wide-necked bifurcation aneurysms pose significant challenges for endovascular treatment. A recent innovation, the stent plus balloon-assisted coiling technique, combines a stent and a balloon to address these aneurysms effectively. PURPOSE: To evaluate the safety and efficacy of the stent plus balloon-assisted coiling for the treatment of wide-necked bifurcation aneurysms. METHODS: We conducted a retrospective review of our endovascular database to identify patients who were treated with this technique and had a satisfactory angiographic follow-up of at least 24 months. Technical success, initial clinical and angiographic outcomes, procedural complications, and follow-up results were analyzed. Angiographic and clinical outcomes were assessed using Modified Raymond-Roy Classification and Modified Rankin Scale, respectively. RESULTS: Our study included 37 aneurysms in 36 patients (26 females) with a mean age of 56.6 years. Mean aneurysm and neck sizes were 7.3 ± 3.5 mm and 3.7 ± 1.0 mm, respectively. Technical success reached 97.2%, with an immediate occlusion rate of 65.7%. At a mean follow-up of 36.5 ± 9.7 months, final angiographic follow-up showed a 91.9% complete occlusion rate. Three aneurysms did not achieve complete occlusion; however, none required retreatment. Complications developed in 32.4% of the procedures. Mortality and morbidity rates were 5.4% and 2.7%, respectively. A good clinical outcome was observed in 91.9% of patients. CONCLUSION: Our results showed that stent plus balloon-assisted coiling technique allows good angiographic outcomes for wide-necked bifurcation aneurysms. However, overall complication rate is high. Subgroup analysis indicated promising safety and efficacy for MCA bifurcation aneurysms, suggesting this technique could be a valuable option for select aneurysms.

Cerebellar lesions in the acute setting of carbon monoxide poisoning.

Bilateral globus pallidus and supratentorial white matter injury are common findings in the acute and chronic setting of carbon monoxide (CO) poisoning. However, isolated cerebellar lesions are extremely rare. In this case report, we shared our findings in siblings with cerebellar injury with different imaging patterns in the acute setting of CO poisoning.

Prediction of Bleeding by the PRECISE-DAPT Score in Patients with Carotid Artery Stenting.

PURPOSE: The predicting bleeding complications in patients undergoing stent implantation and the subsequent dual antiplatelet therapy (PRECISE-DAPT) score predicts the risk of bleeding in patients with dual antiplatelet therapy (DAPT) after percutaneous coronary interventions (PCIs). Patients with carotid artery stenting (CAS) are also treated with DAPT. In this study, we aimed to investigate the performance of the PRECISE-DAPT score in predicting bleeding in patients with CAS. METHODS: Patients who had CAS between January 2018 and December 2020 were retrospectively enrolled. The PRECISE-DAPT score was calculated for each patient. The patients were divided into two groups based on their PRECISE-DAPT score: low < 25 and high ≥ 25. Bleeding and ischemia complications and laboratory data among the two groups were compared. RESULTS: A total of 120 patients with a mean age of 67.3 ± 9.7 years were included. Forty-three patients had high PRECISE-DAPT scores, and 77 patients had low PRECISE-DAPT scores. Six patients developed bleeding events during the six-month follow-up, and five of them were in the PRECISE DAPT score ≥ 25 group. The difference between the two groups regarding bleeding events at six months was significant (P = 0.022). CONCLUSION: The PRECISE-DAPT score might be used for predicting the bleeding risk in patients with CAS, and the bleeding rate was significantly higher in patients with a PRECISE-DAPT score ≥ 25.

Warfarin vs doac: Comparative outcomes of mechanical thrombectomy for acute ischemic stroke in atrial fibrillation patients.

PURPOSE: To compare outcomes of mechanical thrombectomy (MT) for acute ischemic stroke (AIS) in patients with atrial fibrillation (AF) taking warfarin or direct oral anticoagulants (DOACs). METHODS: A total of 71 consecutive patients with AF who underwent MT due to AIS between January 2018 and December 2021 were retrospectively analyzed. Patients were grouped as warfarin versus DOAC group. CHA2DS2-VASc, HAS-BLED, The National Institutes of Health Stroke Scale (NIHSS) at the time of admission and at 24 h, successful recanalization, post- MT complications and technical properties of MT were evaluated. Patients were divided into a good prognosis group, and a mortality group according to the 90th day mRS. RESULTS: HAS-BLED score was significantly higher in DOAC group (p = 0.006) There were no significant differences in stroke severity, successful recanalization rates, post-procedural complications and mRS 90th day scores between patients with warfarin and DOACs. CHA2DS2-VASc, NIHSS at admission and NIHSS on the 24th hour scores were significantly lower in the good mRS group (p = 0.012, p = 0.002, p < 0.001, respectively). CONCLUSION: MT is safe and effective in patients receiving warfarin or DOACs. HASBLED and CHA2DS2-VASc scores can help to predict functional outcome after MT.

Thrombectomy with or without Bridging Thrombolysis for Anterior Circulation Stroke.

Background: Currently, there is still no clear consensus on bridging thrombolysis (BT) before mechanical thrombectomy (MT). In this study, we aimed to compare clinical and procedural outcomes and complication rates of BT versus direct mechanical thrombectomy (d-MT) in anterior circulation stroke. Methods: A total of 359 consecutive anterior circulation stroke patients who received d-MT or BT in our tertiary stroke center between January 2018 and December 2020 were retrospectively analyzed. The patients were divided into two groups as Group d-MT (n = 210) and Group BT (n = 149). The primary outcome was the impact of BT on clinical and procedural outcomes, whereas the secondary outcome was the safety of BT. Results: The incidence of atrial fibrillation was higher in the d-MT group (p = 0.010). The median duration of the procedure was significantly higher in Group d-MT than in Group BT (35 vs 27 min, respectively; P = 0.044). The number of patients achieving good and excellent outcomes was significantly higher in Group BT (p = 0.006 and P = 0.03). The edema/malign infarction rate was higher in the d-MT group (p = 0.003). Successful reperfusion, first-pass effects, symptomatic intra-cranial hemorrhage, and mortality rates were similar between the groups (p > 0.05). Conclusions: In this study, BT seems to yield better clinical and procedural outcomes with lower complication rates than d-MT. These findings may support the additional value of intravenous alteplase in anterior system strokes. Further large-scale, prospective, randomized-controlled studies will clarify the gray lines in this consensus, but this paper is important for reflecting the real-world data in developing countries.

The Angiographic and Clinical Follow-up Outcomes of the Wide-Necked and Complex Intracranial Aneurysms Treated With LVIS EVO-Assisted Coiling.

BACKGROUND: The Low Profile Visible Intraluminal Support EVO (LVIS EVO) is a self-expandable braided stent, which was recently introduced for the treatment of intracranial aneurysms. Full visibility of the stent and a relatively high metal coverage ratio are the unique features of the LVIS EVO. OBJECTIVE: To assess the safety, efficacy, and midterm durability of LVIS EVO stent-assisted coiling for the treatment of wide-necked intracranial aneurysms. METHODS: The endovascular databases were reviewed to identify patients treated with LVIS EVO-assisted coiling. The technical success and immediate clinical/angiographic outcomes were assessed. Periprocedural and delayed complications were evaluated. The follow-up angiographic/clinical outcomes were investigated. The preprocedural/follow-up neurological statuses were assessed with the modified Rankin Scale. RESULTS: One hundred three aneurysms in 103 patients (63 females) with a mean age of 54.9 ± 11.3 years were included. The mean maximum sac diameter was 6.2 ± 2.9 mm. The procedural technical success rate was 100%. Immediate postprocedural angiography showed complete occlusion in 77.7%. The mean duration of the angiographic follow-up was 8.8 ± 3.6 months. Follow-up angiography showed complete aneurysm occlusion in 89% of the 82 patients with angiographic follow-up. Recanalization was observed in 7.3% of 82 patients. Two patients (2.4%) required retreatment. In addition, 8.7% of the patients had at least 1 complication, and 2.9% of the patients developed a permanent morbidity. All patients had mRS scores ≤2. CONCLUSION: The results of this study demonstrate that SAC with LVIS EVO is a relatively safe, efficient, and durable treatment for wide-necked and complex intracranial aneurysms.

Automated LVO detection and collateral scoring on CTA using a 3D self-configuring object detection network: a multi-center study.

The use of deep learning (DL) techniques for automated diagnosis of large vessel occlusion (LVO) and collateral scoring on computed tomography angiography (CTA) is gaining attention. In this study, a state-of-the-art self-configuring object detection network called nnDetection was used to detect LVO and assess collateralization on CTA scans using a multi-task 3D object detection approach. The model was trained on single-phase CTA scans of 2425 patients at five centers, and its performance was evaluated on an external test set of 345 patients from another center. Ground-truth labels for the presence of LVO and collateral scores were provided by three radiologists. The nnDetection model achieved a diagnostic accuracy of 98.26% (95% CI 96.25-99.36%) in identifying LVO, correctly classifying 339 out of 345 CTA scans in the external test set. The DL-based collateral scores had a kappa of 0.80, indicating good agreement with the consensus of the radiologists. These results demonstrate that the self-configuring 3D nnDetection model can accurately detect LVO on single-phase CTA scans and provide semi-quantitative collateral scores, offering a comprehensive approach for automated stroke diagnostics in patients with LVO.

Early and midterm results of complex cerebral aneurysms treated with Silk stent.

INTRODUCTION: Endovascular treatment of intracranial aneurysms has been an effective treatment option. In this paper, we report our experience with the Silk stent (SS) for endovascular treatment of complex intracranial aneurysms and present periprocedural events, immediate results, delayed complications, and imaging and clinical follow-up results. METHODS: We retrospectively examined angiographic images and clinical reports of 76 consecutive patients with 87 intracranial aneurysms who were treated with SSs between March 2008 and June 2011. RESULTS: All aneurysms could be successfully covered technically using implanted SSs, with an overall mortality of 6.6 %. Two transient morbidities (2.6 %) and three permanent morbidities due to embolic events (3.9 %) were observed. Unexpected procedural technical events occurred in 18 procedures (18/78, 23.1 %). Control angiographies were performed in all 71 patients with 82 aneurysms (100 %). Mean angiographic follow-up time was 17.5 ± 11.1 months [range 2-48 months]. Sixteen of the 71 patients with 19 aneurysms had only early angiographic controls in the first 6 months while remaining 55 patients with 63 aneurysms (77.5 %) had late controls after 6 months. Overall control angiographic occlusion rates were as follows: 87.8 % (72/82) total occlusion, 8.5 % residual aneurysm filling, and 3.7 % residual neck filling. The general in-stent stenosis rate in controls was 5.6 % and the stented parent artery occlusion rate was 4.2 %. Five (6.6 %) aneurysms ruptured after stent implantation in our series. CONCLUSION: The Silk stent is an effective tool for the treatment of challenging aneurysms, which have previously demonstrated higher re-growth rates and technical problems, despite unexpected higher hemorrhage rates after treatment and deployment difficulties.

Late self-extraction of a traumatically displaced molar tooth from the maxillary sinus.

An unusual case of late self-extraction of an impacted left maxillary third molar that was displaced into the left maxillary sinus after a traffic accident is described. The patient had been operated on for a maxillofacial trauma after a traffic accident in a plastic and reconstructive surgery department 18 years ago. He was admitted to our clinic 1½ years ago for obstruction and periodically purulent drainage from the left side of the nose. A displaced tooth in the middle meatus was diagnosed, and the patient refused a surgical procedure to remove the tooth. The tooth was self-extracted from the nasal cavity 1 year later. One week after the extraction, the patient was mostly healed and had no complaints.

Feasibility and Results of the Stentectomy Procedure Performed as Rescue Treatment for Acute Thrombosis of Self-Expandable Intracranial Stents: A Case Series.

BACKGROUND: Self-expandable stents have been increasingly used for endovascular treatment of intracranial aneurysms. Because the usage of intracranial stents has increased overall, total numbers of complications associated with these devices have increased. Thrombosis, distortion, or incomplete opening of stents are potential complications that may result in occlusion of the parent artery. In such cases, removal of the stent (stentectomy) may be the only solution to avoid serious clinical consequences. OBJECTIVE: To investigate the feasibility and efficacy of a novel stentectomy technique for removal of thrombosed self-expandable stents. METHODS: A retrospective review was performed of patients who underwent the stentectomy procedure. Initial and follow-up imaging and clinical outcomes were assessed. Immediate postprocedural and follow-up clinical statuses were assessed using the modified Rankin scale. RESULTS: Seven patients were included in this study (mean age: 54.1 years). The stentectomy was successful in 6 of 7 patients (85.7%). Seven stents in 6 patients were successfully removed to treat the acute in-stent thrombosis that was resistant to alternative bail-out treatments. The removed stents were self-expandable braided in 2 patients, flow diverters in 2 patients, and laser cut open-cell stents in 2 patients. Stentectomy failed to retrieve a thrombosed braided stent in 1 patient. The modified Rankin scale score of all patients who underwent a success stentectomy was ≤1. CONCLUSION: The stentectomy procedure using the defined technique is feasible to retrieve thrombosed stents and effective to restore the blood flow. It can be considered a last resort option to treat acute in-stent thrombosis resistant to alternative bail-out treatments.

A joint convolutional-recurrent neural network with an attention mechanism for detecting intracranial hemorrhage on noncontrast head CT.

To investigate the performance of a joint convolutional neural networks-recurrent neural networks (CNN-RNN) using an attention mechanism in identifying and classifying intracranial hemorrhage (ICH) on a large multi-center dataset; to test its performance in a prospective independent sample consisting of consecutive real-world patients. All consecutive patients who underwent emergency non-contrast-enhanced head CT in five different centers were retrospectively gathered. Five neuroradiologists created the ground-truth labels. The development dataset was divided into the training and validation set. After the development phase, we integrated the deep learning model into an independent center's PACS environment for over six months for assessing the performance in a real clinical setting. Three radiologists created the ground-truth labels of the testing set with a majority voting. A total of 55,179 head CT scans of 48,070 patients, 28,253 men (58.77%), with a mean age of 53.84 ± 17.64 years (range 18-89) were enrolled in the study. The validation sample comprised 5211 head CT scans, with 991 being annotated as ICH-positive. The model's binary accuracy, sensitivity, and specificity on the validation set were 99.41%, 99.70%, and 98.91, respectively. During the prospective implementation, the model yielded an accuracy of 96.02% on 452 head CT scans with an average prediction time of 45 ± 8 s. The joint CNN-RNN model with an attention mechanism yielded excellent diagnostic accuracy in assessing ICH and its subtypes on a large-scale sample. The model was seamlessly integrated into the radiology workflow. Though slightly decreased performance, it provided decisions on the sample of consecutive real-world patients within a minute.

Arterial supply of the posterior interventricular sulcus: a CT coronary angiographic study.

OBJECTIVE: The objective of this study was to determine the different vascularization patterns of the posterior interventricular sulcus (PIS) with coronary CT angiography. MATERIALS AND METHODS: Three hundred and fifty-six coronary CT angiograms (CCTA) were retrospectively analyzed in 248 men and 108 women (mean age, 54.9 years ± 13.6 [standard deviation]). The PIS was divided into three segments from the crux cordis to the notch of the cardiac apex according to the American Heart Association classification (basal, mid ventricular and apical), and the artery or arteries supplying each segment were recorded. The relative frequency of the different vascularization patterns was calculated and the distribution of dominance types was recorded. RESULTS: Blood was supplied to the PIS by one or more branches of the right coronary artery (RCA), the left circumflex artery (LCX), or the left anterior descending artery (LAD). We observed 25 different irrigation patterns. In the most frequent pattern (31.3%), the basal and mid-ventricular segments were perfused by a single arterial branch originating from the RCA at the crux, and the apical segment was perfused by the LAD traveling beyond the notch of the cardiac apex and entering the posterior interventricular sulcus. Of the 356 cases, the circulation was right dominant in 310 (87.1%), left dominant in 34 (9.5%), and balanced in 12 (3.4%) cases. Individual segments were perfused by a single artery in 288 (80.9%) cases, and by more than one in the remainder. CONCLUSION: CCTA allows detailed assessment of the arterial supply of the PIS, and allowed to describe 25 subtypes. This information is of potential value to both cardiac surgeons and interventional cardiologists who plan bypass surgery or angioplasty aiming at the posterior interventricular artery.

Initial experience with the CatchView thrombectomy device for acute ischemic stroke.

BACKGROUND: We report our initial experience with the CatchView (CV) thrombectomy device in patients with acute ischemic stroke (AIS). METHODS: A retrospective analysis of 53 of 284 AIS patients (mean age 66.6±14.8 years, range 37-94) treated with a CV device between January 2019 and February 2020 was performed. The baseline characteristics (gender, age, comorbidities, National Institutes of Health Stroke Scale (NIHSS) score, intravenous tissue plasminogen activator (IV-tPA) administration, and occlusion localization) of these subjects were recorded. Modified Thrombolysis in Cerebral Ischemia (mTICI) scores of 2b and 3 were considered to indicate successful recanalization, and subjects with a modified Rankin Scale score of ≤2 on day 90 was considered a good clinical outcomes. RESULTS: The mean NIHSS score was 12.3±3. Successful recanalization was achieved in 45 subjects (84.90%), and the rate of good clinical outcomes on day 90 was 43.39%. The secondary distal embolus rate was 5.66%. Symptomatic hemorrhage was observed in 3.77% of the subjects, and the mortality rate was 13.2%. CONCLUSIONS: Mechanical thrombectomy devices include a wide array of endovascular tools for removing clots in AIS patients. In terms of successful recanalization and good clinical outcomes on day 90, our initial experience with the CV devices was encouraging.

Challenges in Using the Posterior Inferior Cerebellar Artery for Revascularization of the Anterior Inferior Cerebellar Artery: A Microsurgical Anatomic Study.

BACKGROUND: A bypass is usually required to prevent ischemia during the treatment of anterior inferior cerebellar artery (AICA) aneurysms. The intracranial (IC)-to-IC bypass provides several advantages over the extracranial-to-IC bypass in the posterior fossa. However, there are only 2 case reports about AICA revascularization with the posterior inferior cerebellar artery (PICA). We aimed to investigate the microsurgical anatomical challenges for PICA to AICA anastomosis. METHODS: Ten cadaveric heads injected with colored silicone were inspected on both sides using a lateral transcondylar approach. After the donor and recipient arteries were examined from the posterior side, neurovascular contents of the posterior fossa were excised and the origin, course, and variations of both arteries were investigated from the anterior view. The diameters of the AICA and PICA segments and the intersegment distance were measured. RESULTS: PICA variations and posteromedial origins from the vertebral artery were identified in 8 of the 20 right and 6 of the 20 left sides, and the first segment of the PICA was not present in 7 sides. Furthermore, in 18 sides, the PICA was trapped between the lower cranial nerves and dentate ligaments. Therefore the donor artery could not be brought closer than 1 cm to the recipient artery in 19 sides. Moreover, AICA variations were identified in 6 sides, and in 12 sides, the diameter of the recipient artery was <1 mm. CONCLUSIONS: The mostly PICA-related issues made PICA-to-AICA anastomosis unfeasible in all cadaveric heads included in the study.

Inter-vendor performance of deep learning in segmenting acute ischemic lesions on diffusion-weighted imaging: a multicenter study.

There is little evidence on the applicability of deep learning (DL) in the segmentation of acute ischemic lesions on diffusion-weighted imaging (DWI) between magnetic resonance imaging (MRI) scanners of different manufacturers. We retrospectively included DWI data of patients with acute ischemic lesions from six centers. Dataset A (n = 2986) and B (n = 3951) included data from Siemens and GE MRI scanners, respectively. The datasets were split into the training (80%), validation (10%), and internal test (10%) sets, and six neuroradiologists created ground-truth masks. Models A and B were the proposed neural networks trained on datasets A and B. The models subsequently fine-tuned across the datasets using their validation data. Another radiologist performed the segmentation on the test sets for comparisons. The median Dice scores of models A and B were 0.858 and 0.857 for the internal tests, which were non-inferior to the radiologist's performance, but demonstrated lower performance than the radiologist on the external tests. Fine-tuned models A and B achieved median Dice scores of 0.832 and 0.846, which were non-inferior to the radiologist's performance on the external tests. The present work shows that the inter-vendor operability of deep learning for the segmentation of ischemic lesions on DWI might be enhanced via transfer learning; thereby, their clinical applicability and generalizability could be improved.

First multicenter experience using the Silk Vista flow diverter in 60 consecutive intracranial aneurysms: technical aspects.

BACKGROUND: The aim of this study was to assess the technical success and procedural safety of the new Silk Vista device (SV) by evaluating the intraprocedural and periprocedural complication rate after its use in several institutions worldwide. METHODS: The study involved a retrospective review of multicenter data regarding a consecutive series of patients with intracranial aneurysms, treated with the SV between September 2020 and January 2021. Clinical, intra/periprocedural and angiographic data, including approach, materials used, aneurysm size and location, device/s, technical details and initial angiographic aneurysm occlusion, were analyzed. RESULTS: 60 aneurysms were treated with SV in 57 procedures. 66 devices were used, 3 removed and 63 implanted. The devices opened instantaneously in 60 out of 66 (91%) cases and complete wall apposition was achieved in 58 out of 63 (92%) devices implanted. In 4 out of 66 (6%) devices a partial opening of the distal end occurred, and in 5 (8%) devices incomplete apposition was reported. There were 3 (5%) intraprocedural thromboembolic events managed successfully with no permanent neurological morbidity, and 4 (7%) postprocedural events. There was no mortality in this study. The initial occlusion rates in the 60 aneurysms were as follows: O'Kelly-Marotta (OKM) A in 34 (57%) cases, OKM B in 15 (25%) cases, OKM C in 6 (10%) cases, and OKM D in 5 (8%) cases. CONCLUSIONS: Our study demonstrated that the use of the new flow diverter Silk Vista for the treatment of intracranial aneurysms is feasible and technically safe.

Radiological and scintigraphic evaluation versus stereotaxic biopsy for intracranial hypodense lesions: a comparative study.

AIM: Intracranial hypodense lesions include a wide group of pathologies with different structures and characters. Although the radiological imaging properties of these neoplastic and non-neoplastic lesions are similar, treatment modalities for each lesion differs due to histopathological structure. MATERIAL AND METHODS: In this study we have compared the results of radiological and scintigraphic evaluations with the results of stereotaxic biopsies to figure out the diagnostic impact of these non-inasive modalities. 16 patients who admitted to outpatient clinics with headache and/or seizure complaints were included in the study. RESULTS: MR spectroscopic images diagnosed the lesions as accurately as stereotaxic biopsies. CONCLUSION: Although stereotaxic biopsy keeps the label of "gold standard" when establishing a diagnosis for these lesions, modern radiological modalities are quite reliable.