Multiple organ segmentation framework for brain metastasis radiotherapy.

Radiotherapy is a preferred treatment for brain metastases, which kills cancer cells via high doses of radiation meanwhile hardly avoiding damage to surrounding healthy cells. Therefore, the delineation of organs-at-risk (OARs) is vital in treatment planning to minimize radiation-induced toxicity. However, the following aspects make OAR delineation a challenging task: extremely imbalanced organ sizes, ambiguous boundaries, and complex anatomical structures. To alleviate these challenges, we imitate how specialized clinicians delineate OARs and present a novel cascaded multi-OAR segmentation framework, called OAR-SegNet. OAR-SegNet comprises two distinct levels of segmentation networks: an Anatomical-Prior-Guided network (APG-Net) and a Point-Cloud-Guided network (PCG-Net). Specifically, APG-Net handles segmentation for all organs, where multi-view segmentation modules and a deep prior loss are designed under the guidance of prior knowledge. After APG-Net, PCG-Net refines small organs through the mini-segmentation and the point-cloud alignment heads. The mini-segmentation head is further equipped with the deep prior feature. Extensive experiments were conducted to demonstrate the superior performance of the proposed method compared to other state-of-the-art medical segmentation methods.

Case report: Right vertebral and carotid artery anomalies with an aberrant right subclavian artery in two patients.

Abnormal origins of the vertebral artery with supra-aortic vessel variants are exceedingly uncommon. Herein, we present two cases of the vertebral artery originating from the right common carotid artery associated with the right subclavian artery arising separately as the initial branch of the aortic arch, followed by the right common carotid artery. We reviewed the embryology of the anomalous origins of the vertebral and subclavian arteries. These variants can significantly affect surgical planning and cause severe clinical symptoms.

Blood-Blister Aneurysms of the Internal Carotid Artery in Tibetan and Han Populations : A Retrospective Observational Study.

Objective: Blood-blister aneurysms (BBAs) of the internal carotid artery (ICA) are challenging lesions with high morbidity and mortality rates. Although research on BBAs is well documented in different populations, the study of BBAs in the Tibetan population is extremely rare. This study aimed to evaluate the characteristics of BBAs and analyze the treatment modalities and long-term outcomes in the Tibetan population in comparison with the Han population. Methods: The characteristics of patients with BBAs of the ICA from January 2009 to January 2021 at our institution were reviewed. The features of aneurysms, treatment modalities, complications, and follow-up outcomes were retrospectively analyzed. Results: A total of 130 patients (41 Tibetan and 89 Han patients) with BBAs of the ICA who underwent treatment were enrolled. Compared with the Han group, the Tibetan group significantly demonstrated a high ratio of BBAs among ICAs (8.6%, 41/477 vs. 1.6%, 89/5563; p<0.05), a high ratio of vasospasm (34.1%, 14/41 vs. 6.7%, 6/89; p=0.001), a high risk of ischemic events (43.9%, 18/41 vs. 22.5%, 20/89; p<0.05), and a low ratio of good outcomes (modified Rankin Scale, 0-2) at the 1-year follow-up (51.2%, 21/41 vs. 74.2%, 66/89; p<0.05). The multivariate regression model showed that ischemic events significantly contributed to the prediction of outcomes at 1 year. Further analysis revealed that microsurgery and vasospasm were associated with ischemic events. Conclusion: In comparison with Han patients, the Tibetan population had a high ratio of BBA occurrence, a high incidence of ischemic events, and a high ratio of poor outcomes. The endovascular approach showed more benefits in BBA patients.

DeSeg: auto detector-based segmentation for brain metastases.

Delineation of brain metastases (BMs) is a paramount step in stereotactic radiosurgery treatment. Clinical practice has specific expectation on BM auto-delineation that the method is supposed to avoid missing of small lesions and yield accurate contours for large lesions. In this study, we propose a novel coarse-to-fine framework, named detector-based segmentation (DeSeg), to incorporate object-level detection into pixel-wise segmentation so as to meet the clinical demand. DeSeg consists of three components: a center-point-guided single-shot detector to localize the potential lesion regions, a multi-head U-Net segmentation model to refine contours, and a data cascade unit to connect both tasks smoothly. Performance on tiny lesions is measured by the object-based sensitivity and positive predictive value (PPV), while that on large lesions is quantified by dice similarity coefficient (DSC), average symmetric surface distance (ASSD) and 95% Hausdorff distance (HD95). Besides, computational complexity is also considered to study the potential of method in real-time processing. This study retrospectively collected 240 BM patients with Gadolinium injected contrast-enhanced T1-weighted magnetic resonance imaging (T1c-MRI), which were randomly split into training, validating and testing datasets (192, 24 and 24 scans, respectively). The lesions in the testing dataset were further divided into two groups based on the volume size (smallS: ≤1.5 cc,N= 88; largeL: > 1.5 cc,N= 15). On average, DeSeg yielded a sensitivity of 0.91 and a PPV of 0.77 on S group, and a DSC of 0.86, an ASSD 0f 0.76 mm and a HD95 of 2.31 mm onLgroup. The results indicated that DeSeg achieved leading sensitivity and PPV for tiny lesions as well as segmentation metrics for large ones. After our clinical validation, DeSeg showed competitive segmentation performance while kept faster processing speed comparing with existing 3D models.

Indirect carotid-cavernous sinus fistula following mechanical thrombectomy: A case report of a rare iatrogenic injury with progressive presentation.

Introduction: With the increasingly common operation of mechanical thrombectomy (MT) in acute cerebral infarction cases, iatrogenic CCFs were occasionally reported. All of cases reported type A CCFs, and patients were presented with either asymptom from generation of fistula to duration of postoperative follow-up or distinct presentations at once after MT. Case presentation: A 48-year-old postmenopausal female, without history of systemic hypertension and diabetes mellitus, underwent an operation of MT outside our institution about half a year ago. An intraoperative DSA showed an iatrogenic low-flow fistula between meningohypophyseal trunk and ICA. After 4 mouths' postoperative conservative observation, patient's presentation progressed from asymptom to serious optic signs. The patient underwent trans-arterial interventional occlusion. On postoperative day one, visual presentations of patient relieved significantly. Discussion: We discuss the reason for possibility of iatrogenic injury to meningohypophyseal trunk and clinical progressive presentation. A sudden swerve just beyond derivation of meningohypophyseal trunk is prone to being damaged by a misguided guide wire. The progression of clinical presentation, as a focal point in our case, is not reported in iatrogenic before, but some studys still find that spontaneous dural CCFs are inclined to occur in middle-aged or elderly women, especially in postmenopausal women, so age and sex are regarded as background factors of progressing. In addition, the change of drainage route is an immediate cause of progressive presentations. Conclusion: We expect that when a manipulation of MT is conducted leading an iatrogenic CCF, our neurointerventionist should maintain appropriate vigilance on sex, age, menstrual history and medical history, then take an earlier and timely interventional measure.

Treatment of Blood Blister Aneurysms of the Internal Carotid Artery With Pipeline-Assisted Coil Embolization: A Single-Center Experience.

Background: Blood blister aneurysm (BBA) is a complex and rare aneurysm that presents significant treatment challenges. The application of pipeline embolization device (PED)-assisted coiling in the treatment of ruptured BBA remains controversial. This study aimed to report on our experience and assess the safety and efficacy of this strategy. Methods: Between February 2019 and February 2021, 12 patients with ruptured BBAs underwent PED-assisted coil embolization. We collected detailed data about each patient, including demographic information, aneurysmal data, technical details, antiplatelet strategy, operation-related complications, and follow-up outcomes. Results: A total of 12 BBA patients were treated with single PED-assisted coil embolization. One patient experienced intraoperative rupture that was controlled by rapid coiling without clinical consequences. All the patients demonstrated complete occlusion on postoperative angiography. A total of three patients had postoperative complications: left hemiparesis, Broca's aphasia, and right hemiplegia due to vasospasm, and transient hemiparesis. Follow-up angiography revealed that all BBAs were completely occluded, except one with neck residue. All patients had favorable outcomes at discharge and the most recent clinical follow-up (mRS score ≤ 2). Conclusion: Endovascular treatment of BBAs of the internal carotid artery using PED-assisted coil embolization is a safe and effective strategy. This has contributed to the understanding of BBA therapy and provides a potentially optimal treatment option for this intractable lesion.

Treatment of Familial Hypercholesterolemia with Intracranial Xanthoma: Case Report.

Intracranial xanthoma is a rare benign intracranial tumor. It often occurs in patients with hyperlipidemia. Intracranial xanthomas grow slowly, and clinical symptoms only appear when the mass compresses the surrounding tissues, so early diagnosis of the disease is difficult.

Using a Convolutional Neural Network and Convolutional Long Short-term Memory to Automatically Detect Aneurysms on 2D Digital Subtraction Angiography Images: Framework Development and Validation.

BACKGROUND: It is hard to distinguish cerebral aneurysms from overlapping vessels in 2D digital subtraction angiography (DSA) images due to these images' lack of spatial information. OBJECTIVE: The aims of this study were to (1) construct a deep learning diagnostic system to improve the ability to detect posterior communicating artery aneurysms on 2D DSA images and (2) validate the efficiency of the deep learning diagnostic system in 2D DSA aneurysm detection. METHODS: We proposed a 2-stage detection system. First, we established the region localization stage to automatically locate specific detection regions of raw 2D DSA sequences. Second, in the intracranial aneurysm detection stage, we constructed a bi-input+RetinaNet+convolutional long short-term memory (C-LSTM) framework to compare its performance for aneurysm detection with that of 3 existing frameworks. Each of the frameworks had a 5-fold cross-validation scheme. The receiver operating characteristic curve, the area under the curve (AUC) value, mean average precision, sensitivity, specificity, and accuracy were used to assess the abilities of different frameworks. RESULTS: A total of 255 patients with posterior communicating artery aneurysms and 20 patients without aneurysms were included in this study. The best AUC values of the RetinaNet, RetinaNet+C-LSTM, bi-input+RetinaNet, and bi-input+RetinaNet+C-LSTM frameworks were 0.95, 0.96, 0.92, and 0.97, respectively. The mean sensitivities of the RetinaNet, RetinaNet+C-LSTM, bi-input+RetinaNet, and bi-input+RetinaNet+C-LSTM frameworks and human experts were 89% (range 67.02%-98.43%), 88% (range 65.76%-98.06%), 87% (range 64.53%-97.66%), 89% (range 67.02%-98.43%), and 90% (range 68.30%-98.77%), respectively. The mean specificities of the RetinaNet, RetinaNet+C-LSTM, bi-input+RetinaNet, and bi-input+RetinaNet+C-LSTM frameworks and human experts were 80% (range 56.34%-94.27%), 89% (range 67.02%-98.43%), 86% (range 63.31%-97.24%), 93% (range 72.30%-99.56%), and 90% (range 68.30%-98.77%), respectively. The mean accuracies of the RetinaNet, RetinaNet+C-LSTM, bi-input+RetinaNet, and bi-input+RetinaNet+C-LSTM frameworks and human experts were 84.50% (range 69.57%-93.97%), 88.50% (range 74.44%-96.39%), 86.50% (range 71.97%-95.22%), 91% (range 77.63%-97.72%), and 90% (range 76.34%-97.21%), respectively. CONCLUSIONS: According to our results, more spatial and temporal information can help improve the performance of the frameworks. Therefore, the bi-input+RetinaNet+C-LSTM framework had the best performance when compared to that of the other frameworks. Our study demonstrates that our system can assist physicians in detecting intracranial aneurysms on 2D DSA images.

Anterior endoscopic transcortical approach to a pineal region cavernous hemangioma.

A 57-year-old female presented with headache and dizziness for 3 months. Preoperative MRI revealed a lesion located at the pineal region and back side of the third ventricle, accompanied by hydrocephalus. The infratentorial supracerebellar approach may cause visuomotor, acousticomotor, and hearing disturbances. With the patient in a supine position, the authors used a frontal linear incision that was 3 cm anterior to the coronal suture and 2 cm away from the midline and an anterior endoscopic transcortical approach, which could achieve endoscopic third ventriculostomy, alleviating and preventing hydrocephalus due to postoperative adhesion and resection of the lesion at the same time. The pathological diagnosis was cavernous hemangioma. The video can be found here: https://stream.cadmore.media/r10.3171/2021.4.FOCVID215.

Effectiveness, Safety and Risk Factors of Woven EndoBridge Device in the Treatment of Wide-Neck Intracranial Aneurysms: Systematic Review and Meta-Analysis.

OBJECTIVE: To assess the current efficacy, safety, and risk factors of the Woven EndoBridge (WEB) in treating wide-neck intracranial aneurysms. METHODS: We searched the PubMed, Ovid MEDLINE, and Embase databases between December 1, 2012 and June 30, 2018. Studies were included if they featured ≥5 patients undergoing WEB for wide-neck intracranial aneurysms, reported an angiographic or clinical outcome and risk factors, and were published after December 1, 2012. Major outcomes included initial or short-term complete and adequate occlusion. Secondary outcomes included treatment failure, recanalization, mortality, morbidity, and complication rates. A random-effect model was used to pool the data. To assess risk factors for short-term angiographic outcomes and the most common complications, we conducted subgroup analyses. RESULTS: We included 36 studies (1759 patients with 1749 aneurysms). The initial complete and adequate occlusion rates were 35% and 77%, respectively. The short-term (mean follow-up, 9.34 months) complete and adequate occlusion rates were 53% and 80%, respectively. Thromboembolism and recanalization had the highest occurrence (both 9%), followed by mortality (7%), morbidity (6%), failure (5%) and intraoperative rupture (3%). The following factors were related to higher short-term obliteration rates: unruptured status, in the anterior circulation, a medium neck (4-9.9 mm), newer-generation WEB, and treatment without additional devices. Ruptured status, anterior circulation, preoperative antiplatelet therapy, and newer-generation WEB were not significantly related to thromboembolism. CONCLUSIONS: WEB is safe and shows promising efficacy in treating wide-neck intracranial aneurysms. We preliminarily identified several risk factors for short-term angiographic outcomes.

Automatic detection on intracranial aneurysm from digital subtraction angiography with cascade convolutional neural networks.

BACKGROUND: An intracranial aneurysm is a cerebrovascular disorder that can result in various diseases. Clinically, diagnosis of an intracranial aneurysm utilizes digital subtraction angiography (DSA) modality as gold standard. The existing automatic computer-aided diagnosis (CAD) research studies with DSA modality were based on classical digital image processing (DIP) methods. However, the classical feature extraction methods were badly hampered by complex vascular distribution, and the sliding window methods were time-consuming during searching and feature extraction. Therefore, developing an accurate and efficient CAD method to detect intracranial aneurysms on DSA images is a meaningful task. METHODS: In this study, we proposed a two-stage convolutional neural network (CNN) architecture to automatically detect intracranial aneurysms on 2D-DSA images. In region localization stage (RLS), our detection system can locate a specific region to reduce the interference of the other regions. Then, in aneurysm detection stage (ADS), the detector could combine the information of frontal and lateral angiographic view to identify intracranial aneurysms, with a false-positive suppression algorithm. RESULTS: Our study was experimented on posterior communicating artery (PCoA) region of internal carotid artery (ICA). The data set contained 241 subjects for model training, and 40 prospectively collected subjects for testing. Compared with the classical DIP method which had an accuracy of 62.5% and an area under curve (AUC) of 0.69, the proposed architecture could achieve accuracy of 93.5% and the AUC of 0.942. In addition, the detection time cost of our method was about 0.569 s, which was one hundred times faster than the classical DIP method of 62.546 s. CONCLUSION: The results illustrated that our proposed two-stage CNN-based architecture was more accurate and faster compared with the existing research studies of classical DIP methods. Overall, our study is a demonstration that it is feasible to assist physicians to detect intracranial aneurysm on DSA images using CNN.

Risk Factors for Recurrence of Chronic Subdural Hematoma: A Single Center Experience.

OBJECTIVE: Chronic subdural hematoma (CSDH) is a common form of intracranial hemorrhage with a substantial recurrence rate. We aimed to investigate the predictive factors for the postsurgical recurrence of CSDH. METHODS: We retrospectively reviewed the medical records of patients with CSDH who underwent surgery in West China Hospital between January 2012 and June 2018. Univariate and multivariate analyses were performed to identify the relationships between recurrence of CSDH and factors such as age, sex, history of injury, Markwalder grading, computed tomography findings, surgical methods, and outcomes. RESULTS: A total of 328 patients (281 men and 47 women) aged 22-93 years (mean age, 65.14 ± 13.76 years) were included. Computed tomography findings at admission showed mixed density hematoma in 136 patients, isodensity hematoma in 140, high-density hematoma in 34, and low-density hematoma in 18. The mortality and recurrence rate were 0.30% (1 of 328) and 2.44% (8 of 328), respectively. Six months postoperatively, 327 patients had Markwalder grade 0. Hematoma recurred in 8 patients of which 7 were mixed density hematoma and 1 was isodensity hematoma. Six patients who underwent craniotomy had thickened inner neomembrane that was resected. Univariate and multivariate analyses found mixed density hematoma to be an independent risk factor for the recurrence of CSDH. CONCLUSIONS: Burr hole craniostomy with irrigation and closed-system drainage is effective for the surgical treatment of CSDH. Mixed density hematoma is an independent predictor for the recurrence of CSDH. Presence of thick inner neomembrane might be the primary cause of CSDH recurrence.

The Effectiveness of Lumbar Drainage in the Management of Delayed or Recurrent Cerebrospinal Fluid Leaks: A Retrospective Case Series in a Single Center.

OBJECTIVE: Little is known about the effectiveness of lumbar drainage (LD) in the treatment of delayed or recurrent cerebrospinal fluid (CSF) leaks. We report our institutional experience and the effectiveness of LD in the management of delayed or recurrent CSF leaks. METHODS: Between January 2014 and December 2018, a total 21 patients with delayed or recurrent CSF leaks were enrolled in the research. All patients were treated conservatively for 48 hours, and LD was prescribed if CSF leaks still existed after 48 hours. If LD failed, endoscopic endonasal surgery (EES) was performed as soon as possible. Medical records were collected to analyze the effectiveness of LD. RESULTS: Among 21 patients, 4 patients experienced resolution with conservative treatment, and 17 patients were treated by CSF diversion by LD. The total cure rate of LD was 9/17 (52.9%). The cure rate was not statistically significantly different (relative risk = 3.33; Fisher exact test P = 0.131) between the traumatic group (8/12, 66.7%) and the transsphenoidal surgery group (1/5, 20.0%). During the follow-up time, no recurrence of CSF leaks was observed. CONCLUSIONS: The cure rate of LD in delayed or recurrent CSF leaks was lower than that of initial treatment with LD. The cure rate in the traumatic group tended to be higher than that in the transsphenoidal surgery group. EES can be used as a remedial treatment for patients in whom LD has failed.

Application of the Willis Covered Stent in the Treatment of Ophthalmic Artery Segment Aneurysms: A Single-Center Experience.

OBJECTIVE: The purpose of this study is to introduce our initial experience with the evaluation of the feasibility of using Willis covered stents (WCSs) in the treatment of complicated ophthalmic artery (OA) segment aneurysms. METHODS: Of the 162 patients with OA segment aneurysms treated by endovascular techniques in West China Hospital from January 2015 to August 2017, a total of 26 patients treated with WCSs were included in the study. RESULTS: Twenty-six patients with 26 aneurysms were included (mean age, 57.0 years; range, 22-76 years). The cohort had 20 patients with large or giant aneurysms, 3 patients with blood blister aneurysms, and 3 patients with pseudoaneurysms. Ten aneurysms were OA type, and 16 were internal carotid artery (ICA) type. Twenty-four patients were treated with 1 stent, and 2 patients were treated with 2 stents. Among the 26 patients, 2 patients had minimal endoleak, and 24 patients had complete occlusion after immediate postoperative angiography. One patient who had complete occlusion experienced contrast agent extravasation, and this phenomenon disappeared by balloon compression during the procedure. The 3- to 15-month angiographic follow-up showed that all patients experienced complete occlusion, including 2 patients with minimal endoleak during immediate postprocedural angiography. Two patient showed signs of in-stent stenosis. Clinical follow-up demonstrated that no delayed thromboembolic or ischemic events were recorded in the stent-grafted vascular region and no bleeding occurred in any of the patients (except 1 patient who experienced subarachnoid hemorrhage, left frontal lobe hemorrhage, and hydrocephalus 10 days after the procedure). CONCLUSIONS: WCSs may provide an alternative solution for treating complex OA segment aneurysms by reconstruction and preservation of the ICA. Our study also confirms the safety, efficacy, and midterm durability of WCSs for complex OA segment aneurysms.

Application of the Willis Covered Stent in the Treatment of Carotid-Cavernous Fistula: A Single-Center Experience.

BACKGROUND: The purpose of the present study was to describe our single-institutional experience of treating direct carotid-cavernous fistulas (DCCFs) with Willis covered stents (WCSs). METHODS: Of a total of 31 DCCFs, 10 were treated with WCSs (Microport, Shanghai, China) at West China Hospital from January 2015 to December 2016. The indications for treatment, perioperative findings, and postoperative and follow-up results were collected and analyzed. RESULTS: All 10 patients had successful deployment of WCSs. Complete exclusion of the fistula was achieved in 6 patients immediately after deployment of 1 stent. Endoleak was observed in 4 patients (patients 2, 4, 5, and 9). Thus, repeat dilation of the stent with greater pressure was performed, which resolved the endoleak in 2 patients (patients 2 and 9). The endoleak of the other 2 patients persisted after repeat dilation of the balloon. Hence, a second stent was deployed in these 2 patients (patients 4 and 5), which eliminated the endoleak in patient 4. However, patient 5 continued to have a minimal endoleak. Nine patients had fistulas successfully occluded by WCSs during the follow-up period. One patient experienced recurrence of a DCCF at the 10-day follow-up point. We chose coil embolization to address this DCCF. No stenosis of the internal carotid artery or DCCF recurrence, except that in the abovementioned patient, was observed. CONCLUSIONS: WCS was proved to be an alternative treatment method for complex DCCFs through reconstruction and preservation of the internal carotid artery. Our study also confirmed the safety, efficacy, and midterm durability of WCSs for complex DCCFs without any serious delayed complications.