Alterations in Normal Aging Revealed by Cortical Brain Network Constructed Using IBASPM.

Normal aging has been linked with the decline of cognitive functions, such as memory and executive skills. One of the prominent approaches to investigate the age-related alterations in the brain is by examining the cortical brain connectome. IBASPM is a toolkit to realize individual atlas-based volume measurement. Hence, this study seeks to determine what further alterations can be revealed by cortical brain networks formed by IBASPM-extracted regional gray matter volumes. We found the reduced strength of connections between the superior temporal pole and middle temporal pole in the right hemisphere, global hubs as the left fusiform gyrus and right Rolandic operculum in the young and aging groups, respectively, and significantly reduced inter-module connection of one module in the aging group. These new findings are consistent with the phenomenon of normal aging mentioned in previous studies and suggest that brain network built with the IBASPM could provide supplementary information to some extent. The individualization of morphometric features extraction deserved to be given more attention in future cortical brain network research.

[Preliminary clinical application of vascular interventional robot].

OBJECTIVE: To verify the feasibility and safety of the vascular interventional vascular interventional surgical robot system applied to vascular interventional operation. METHODS: From March to September 2013, 10 patients had undergone robot-assisted cerebral angiography. There were 6 male and 4 female patients; aged from 19 to 58 years, with an average age of 38.4 years. The operation were carried out by neurosurgeons and vascular interventional robot. After successfully implanted of femoral artery sheath by hand, the catheter was fixed on the robot, under the guidance of navigation image the surgeon manipulate the master part and control the slave part of robot by sending command through network transmission, finally finished the whole cerebral angiography. The operation time was recorded from placing the sheath into femoral artery to finishing cerebrovascular selective angiography, simultaneously the time of staff under exposure of X ray was recorded, and the position difference between the setted targets and the actual position(positioning accuracy). RESULTS: It took 25-41 minutes to finish the cerebral angiography, the average time was (31 ± 5) minutes, and the robot-assisted angiography went quickly and smoothly without surgical complications. The remote positioning accuracy was (1.03 ± 0.23) mm. The time of staff under exposure of X ray was 0 minute, the entire experimental process was basically implemented mechanization and automation. CONCLUSION: This system basically achieves initial medical purposes, such as reducing the radiation, facilitating interventional procedures on the basis of enhancing the image navigation, shorting the operation time, and improve the quality of operation.

Multi-task global optimization-based method for vascular landmark detection.

Vascular landmark detection plays an important role in medical analysis and clinical treatment. However, due to the complex topology and similar local appearance around landmarks, the popular heatmap regression based methods always suffer from the landmark confusion problem. Vascular landmarks are connected by vascular segments and have special spatial correlations, which can be utilized for performance improvement. In this paper, we propose a multi-task global optimization-based framework for accurate and automatic vascular landmark detection. A multi-task deep learning network is exploited to accomplish landmark heatmap regression, vascular semantic segmentation, and orientation field regression simultaneously. The two auxiliary objectives are highly correlated with the heatmap regression task and help the network incorporate the structural prior knowledge. During inference, instead of performing a max-voting strategy, we propose a global optimization-based post-processing method for final landmark decision. The spatial relationships between neighboring landmarks are utilized explicitly to tackle the landmark confusion problem. We evaluated our method on a cerebral MRA dataset with 564 volumes, a cerebral CTA dataset with 510 volumes, and an aorta CTA dataset with 50 volumes. The experiments demonstrate that the proposed method is effective for vascular landmark localization and achieves state-of-the-art performance.

Cross-modality cerebrovascular segmentation based on pseudo-label generation via paired data.

Accurate segmentation of cerebrovascular structures from Computed Tomography Angiography (CTA), Magnetic Resonance Angiography (MRA), and Digital Subtraction Angiography (DSA) is crucial for clinical diagnosis of cranial vascular diseases. Recent advancements in deep Convolution Neural Network (CNN) have significantly improved the segmentation process. However, training segmentation networks for all modalities requires extensive data labeling for each modality, which is often expensive and time-consuming. To circumvent this limitation, we introduce an approach to train cross-modality cerebrovascular segmentation network based on paired data from source and target domains. Our approach involves training a universal vessel segmentation network with manually labeled source domain data, which automatically produces initial labels for target domain training images. We improve the initial labels of target domain training images by fusing paired images, which are then used to refine the target domain segmentation network. A series of experimental arrangements is presented to assess the efficacy of our method in various practical application scenarios. The experiments conducted on an MRA-CTA dataset and a DSA-CTA dataset demonstrate that the proposed method is effective for cross-modality cerebrovascular segmentation and achieves state-of-the-art performance.

Hemodynamic study on the therapeutic effects of varying diameter embolic coils in the treatment of intracranial aneurysms.

Endovascular coiling is the predominant method for treating cerebral aneurysms. Extensive reports on selecting coil length, hardness, and material are available. However, the impact of coil diameter on postoperative outcomes remains unclear. This study enrolled six personalized geometric models of intracranial aneurysms: three bifurcation aneurysms and three sidewall aneurysms. Four coil models were constructed by changing the coil diameter. Coil embolization was simulated using the finite element method. Computational fluid dynamics was used to characterize hemodynamics in the aneurysms after embolization. Evaluation parameters included velocity reduction, wall shear stress (WSS), low WSS (LWSS), oscillatory shear index (OSI), relative residence time (RRT), and residual flow volume in the aneurysms. At the peak time (t = 0.17 s), the proportion of LWSS area in bifurcation aneurysms increase with the rise in coil diameter: 0.8D, 71.28 ± 12.62% versus 1D, 74.97 ± 19.17% versus 1.2D, 78.88 ± 18.56% versus 1.4D, 84.00 ± 11.53% (mean ± SD). The proportion of high OSI area decreases as the coil diameter increases: 0.8D, 4.41% ± 2.82% versus 1.0D, 3.78 ± 3.33% versus 1.2D, 2.28% ± 1.77% versus 1.4D, 1.58% ± 1.11% (mean ± SD). The proportion of high RRT area increases as the coil diameter rises: 0.8D, 3.40% ± 1.68% versus 1.0D, 7.67 ± 4.12% versus 1.2D, 9.84% ± 9.50% versus 1.4D, 22.29% ± 14.28% (mean ± SD). Side wall aneurysms do not exhibit the aforementioned trend. Bifurcation aneurysms plugged with a coil of 1.4 times the diameter have the largest RFVs (<10 mm/s) within the group. Aforementioned patterns are not found in sidewall aneurysms. In the treatment of aneurysms with coiling, varying coil diameters can result in different hemodynamic environments within the aneurysm. Larger coil diameters have improved hemodynamic performance for bifurcation aneurysms. However, coil diameter and embolization effectiveness have no significant relationship for sidewall aneurysms.

Verification of software-based preoperative simulation of flow diverters in clinical cases.

OBJECTIVE: The authors sought to verify the use of a preoperative simulation software for the treatment of intracranial aneurysms using flow diverters (FDs) based on three-dimensional rotational angiography (3DRA) data. METHODS: Based on 3DRA data, the preoperative simulation software (UKNOW) was used to simulate the deployment of virtual FDs. The length and dimensions of virtual and real devices were compared. The deployment plan recommended by the UKNOW software was preliminarily used to complete implantations in the real world. During the experiment, experienced neurointerventional experts were responsible for supervising and judging information such as the length, dimension, and deployment location of the FDs. RESULTS: This study retrospectively analyzed the data of 29 patients who received FD treatment. There was no statistical difference between the length of the real device and the virtual device (p = 0.6). The dimensions of FDs recommended by the software were consistent with the dimensions used in 24 out of the 29 real cases. In four of the remaining five cases, neurointerventional experts found that the FD dimensions recommended by the software were superior to those were actually used. Thus, the accuracy rate for FD dimension recommendations by the UKNOW software was 96.6% (28/29). Procedures performed in five cases using deployment plans recommended by the UKNOW software all achieved good postoperative results; the deployment positions of the device were reasonable, and all devices showed good wall adherence. CONCLUSIONS: UKNOW software could accurately simulate the length and deployment position of the real FDs and provide suitable device dimensions.

Gene mutation landscape of a rare patient with acute megakaryoblastic leukemia after treatment of intracranial germ cell tumor.

Introduction: It was first reported that germ cell tumor patients suffer from hematologic malignancies 37 years ago. Since then, the number of relevant reports has increased each year, with most cases being mediastinal germ cell tumor. Theories have been proposed to explain this phenomenon, including a shared origin of progenitor cells, the effects of treatment, and independent development. However, up to now, no widely accepted explanation exists. The case with acute megakaryoblastic leukemia and intracranial germ cell tumor has never been reported before and the association is far less known. Methods: We used whole exome sequencing and gene mutation analysis to study the relationship between intracranial germ cell tumor and acute megakaryoblastic leukemia of our patient. Results: We report a patient who developed acute megakaryoblastic leukemia after treatment for an intracranial germ cell tumor. Through whole exome sequencing and gene mutation analysis, we identified that both tumors shared the same mutation genes and mutation sites, suggesting they originated from the same progenitor cells and differentiated in the later stage. Discussion: Our findings provide the first evidence supporting the theory that acute megakaryoblastic leukemia and intracranial germ cell tumor has the same progenitor cells.

[Magnetic resonance spectroscopy-guided stereotactic biopsy for brain lesion].

OBJECTIVE: To study the clinical value of magnetic resonance spectroscopy (MRS) image in stereotactic biopsy for brain lesion. METHODS: From April 2008 to April 2010, 126 cases (72 male and 54 female, aged from 10 to 82 years, mean 45 years) of brain lesion which were difficult to diagnose were divided into two groups by random number table, 62 cases were executed for MRI-guided frameless stereotactic biopsy (MRI group), 64 cases were executed for MRI and MRS-guided frameless stereotactic biopsy (MRS group). Operation used MRI and Three-dimensional MRS image to locate, and used frameless CAS-R-2 robots to carry out the positioning operating. RESULTS: No surgery-related deaths and infections. Pathological diagnosis was 106 cases of brain tumors, 6 cases of inflammatory disease, 4 cases of tumor-like demyelinating disease and multiple sclerosis, 3 cases of neurodegenerative disease, 7 cases failed to obtain positive pathological diagnosis. The total rate of positive diagnosis was 94.4%, the positive rate in MRS-guided stereotactic biopsy group was 98.4% (63/64), the positive rate of conventional MRI-guided biopsy group was 90.3% (56/62), and there was statistically significant difference between the two groups (χ(2) = 3.92, P = 0.047). Four cases presented with postoperative complications, the complication rate was 3.2% (4/126); the complications were cerebral hemorrhage associated with aphasia, epilepsy, subcutaneous hematoma, gastrointestinal bleeding, which were improved after treatment. CONCLUSIONS: MRS-guided stereotactic biopsy group has a higher positive rate than MRI-guided stereotactic biopsy group, indicating that this method can improve the positive rate of diagnosis, and thus will help to formulate treatment plan for brain lesion.

[Experimental study of angiography using vascular interventional robot-2(VIR-2)].

OBJECTIVE: To verify the feasibility and safety of new vascular interventional robot system used in vascular interventional procedures. METHODS: Vascular interventional robot type-2 (VIR-2) included master-slave parts of body propulsion system, image navigation systems and force feedback system, the catheter movement could achieve under automatic control and navigation, force feedback was integrated real-time, followed by in vitro pre-test in vascular model and cerebral angiography in dog. Surgeon controlled vascular interventional robot remotely, the catheter was inserted into the intended target, the catheter positioning error and the operation time would be evaluated. RESULTS: In vitro pre-test and animal experiment went well; the catheter can enter any branch of vascular. Catheter positioning error was less than 1 mm. The angiography operation in animal was carried out smoothly without complication; the success rate of the operation was 100% and the entire experiment took 26 and 30 minutes, efficiency was slightly improved compared with the VIR-1, and the time what staff exposed to the DSA machine was 0 minute. The resistance of force sensor can be displayed to the operator to provide a security guarantee for the operation. No surgical complications. CONCLUSIONS: VIR-2 is safe and feasible, and can achieve the catheter remote operation and angiography; the master-slave system meets the characteristics of traditional procedure. The three-dimensional image can guide the operation more smoothly; force feedback device provides remote real-time haptic information to provide security for the operation.

WITHDRAWN: Anatomic differences in first episode schizophrenia: a deformation-based morphometry MRI Study.

This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

[Experimental study of angiography using vascular interventional robot].

OBJECTIVE: To assess the feasibility and safety of vascular interventional surgery by using vascular interventional robot system (VIRS). METHODS: VIRS included image navigation systems and body propulsion systems, and adopted a master-slave structure. The surgeon sat at the master site, sending controlling instructions to the robot fixed at the slave site, and then the robot translated these instructions into catheter motion. A 3D vascular model was reconstructed so that the surgeon can perform surgical planning easily. In glass model and animal experiments, the surgeon remotely controlled VIRS, which inserted a catheter into predefined targets, and the catheter positioning error and robotic surgery time were measured. RESULTS: The robot was initially tested on a glass vascular model. Under robotic manipulation, the catheter could enter an arbitrary branch of the vascular model. The catheter positioning error was less than 1 mm. Then robotic interventional surgery was performed successfully in ten adult dogs. The renal artery and the vertebral artery angiography carried out smoothly without complication. Experiment took 35 minutes, and the time what staff exposed to the digital subtraction angiography (DSA) machine was 0 minute. CONCLUSION: Vascular interventional surgical robot system is safe and feasible, and can achieve the catheter remote operation, meet the requirements of angiography basically.

Application of a robotic telemanipulation system in stereotactic surgery.

To assess the clinical usefulness, accuracy, and safety of telemanipulation for frameless stereotactic surgery using the CAS-BH5 robot system, we prospectively evaluated 10 patients (age: 5-79 years; mean: 44 years) who underwent telemanipulation frameless stereotactic operations from September to December 2005. The CAS-BH5 robot system consists of three main parts: a planning subsystem, a surgical localization subsystem, and a telemanipulation subsystem. Specifically, CAS-BH5 is capable of network communication, video transmission, graphic simulation and human-machine interaction, and thus facilitates remote planning and transmission of neuronavigation data, monitoring and manipulating. Telemanipulation was performed via a digital data network with a speed of 2,000 kilobytes per second by a neurosurgeon in Beijing while the patients were located in Yan'an, 1,300 km away. Remote fiducial registration was performed with a mean accuracy of 1.05 mm and the standard difference between the planned and actual trajectory was 0.13 mm. The mean time from fiducial registration to closure was 30.2 +/- 1.66 min. At 12-month follow-up, 90% of patients had improved neurologically. There were no complications. This preliminary data indicates that telemanipulation in frameless stereotactic surgeries is feasible, reliable and safe. In the future, we believe that telemanipulation will facilitate collaboration between surgeons, enhance training, allow for sharing of resources, and have wide applications in the field of neurosurgery.

[Clinical analysis of 1434 cases of frameless stereotactic operation].

OBJECTIVE: Stereotactic operations were performed using a frameless stereotactic instrument manufactured by CAS-R-2 instead of traditional stereotactic frame. The aim of this study was to assess the clinical usefulness, accuracy and safety of frameless stereotactic instrument. METHODS: The clinical data of 1434 patients was retrospectively reviewed. The mean age was 30.7 years (from 0.2 to 89.0 years). Each patient underwent frameless CT/MRI image-guided stereotactic surgery by this robot system from January 1997 to January 2006. The accuracy of position and improvement of symptom were observed. The averaged period of followed-up was 24 months (from 3 to 48 months). RESULTS: The surgical procedures were performed successfully in all cases. All targets were pointed accurately at first time during the operation. The total effective rate was 93.3% without serious operation related complications. CONCLUSIONS: Compared with the traditional stereotactic operations, this method has some advantages, such as releasing the patient's pain, convenience the doctors, extending the range of indications and increasing the safety and effective of operation.

[Clinical application of robotic tele-manipulation system in stereotactic surgery].

OBJECTIVE: To assess the clinical usefulness, accuracy, and safety of tele-manipulation for frameless stereotactic surgery using the CAS-R-5 robot system. METHODS: We prospectively evaluated 32 patients underwent tele-manipulation of frameless stereotactic operations from Sep. 2005 to Sep. 2006. Tele-manipulations were performed via a digital data network by a neurosurgeon in Beijing while the patients were located in Yan'an. The distance is 1300 kilometers away. The accuracy of location and improvement of symptom were observed after operation. The period of follow-up was from 3 to 14 months (the average was 12 months). RESULTS: The surgical operations in 32 cases were successful. Remote fiducial registration was performed with a mean accuracy of 1. 50 mm and the standard difference were 0.32 mm between the planned and actual target. There were no complications. CONCLUSIONS: Diagnosis and treatment for intracranial disease by tele-manipulation frameless stereotactic surgeries are reliable and safe.

Clinical application of a vascular interventional robot in cerebral angiography.

BACKGROUND: Cardiovascular and cerebrovascular diseases have become the leading cause of death for people, and endovascular surgery has become the main therapeutic method. Robot technology would overcome some limitations of conventional surgery, and has good prospects. METHODS: A total of 15 patients received cerebral angiography assisted by a vascular interventional robot following preoperative examination, with approval from the hospital ethics committee and informed consent by the patients' families. RESULTS: Robot-assisted angiography was performed quickly and smoothly without surgical complications. The remote positioning accuracy was 1.05 ± 0.28 mm. The time staff were exposed to the digital subtraction angiography (DSA) machine was 0 min. The entire experimental process was mechanized and automated. CONCLUSION: This system achieved the preliminary purposes, including a reduction in radiation for the surgeons, facilitation of the application of interventional procedures, a decrease in operation time, and an improvement in operation quality.

Neural stem cell transplantation for the treatment of primary torsion dystonia: A case report.

Primary torsion dystonia (PTD) occurs due to a genetic mutation and often advances gradually. Currently, there is no therapy available that is able to inhibit progression. Neural stem cells (NSCs) are being investigated as potential therapies for neurodegenerative diseases, such as stroke and trauma. The present study evaluated the clinical effectiveness of NSC transplantation in an 18-year-old male patient with PTD, to assess the ability of this therapy to inhibit PTD progression. Genetic testing of the patient revealed a mutation in the torsion dystonia-1 (DYT1) gene (907-909 delGAG). NSCs were bilaterally implanted in the globus pallidus of the patient through stereotactic surgery. Prior to surgery, the patient's Burke-Fahn-Marsden dystonia movement score (BFMDMS) was 21, which progressively decreased after surgery to 18, 17, 15 and 13 at 1, 2, 3 and 4 postoperative years, respectively. BFMDMS was improved by 38.1% over the 4 postoperative years. Although computed tomography and magnetic resonance imaging examinations showed no significant changes prior to and following surgery, postoperative brain positron emission tomography scans revealed increased glucose metabolism in the transplanted region. The clinical efficacy of NSC transplantation in this patient suggests its potential for the treatment of DYT1-positive patients with PTD.

Brain differences in first-episode schizophrenia treated with quetiapine: a deformation-based morphometric study.

RATIONALE: With the development of various imaging techniques, the deformation-based morphometry (DBM) method provides an objective automatic examination of the whole brain. OBJECTIVES: This study aims to assess the abnormalities in the brains of first-episode schizophrenia (FES) patients treated with quetiapine using another advanced nonrigid registration method, hierarchical attribute matching mechanism for elastic registration, through the application of DBM in the entire brain. METHODS: Thirty FES patients and 30 normal controls were grouped by age and handedness and subjected to magnetic resonance imaging examination. The patients had relatively short durations of untreated psychosis (DUP; 6.4 ± 5.2 months), and only a single antipsychotic drug, quetiapine (dosage, 200 ± 75 mg), was used for treatment. Statistically significant changes in regional volume were analyzed via DBM. In addition, a voxel-wise analysis of correlations between the duration of treatment or dosage and volume was also performed. RESULTS: Compared with control subjects, FES patients showed contracted regions located in Brodmann area (BA) 42 and BA 19. By contrast, expanded regions were observed in BA 38, BA 21, BA 6 and 8, and left cerebellum. A negative correlation was observed between dosage and volume in the hippocampus, while a positive correlation was found in the caudate. Meanwhile, a negative correlation was observed between duration of treatment and volume in BA 38. CONCLUSION: Both regional volume reductions and increases were detected in the brains of FES patients treated with quetiapine compared with healthy control subjects. Such differences may be partially relevant to dosage and treatment duration in clinic.

Thalamic segmentation based on improved fuzzy connectedness in structural MRI.

Thalamic segmentation serves an important function in localizing targets for deep brain stimulation (DBS). However, thalamic nuclei are still difficult to identify clearly from structural MRI. In this study, an improved algorithm based on the fuzzy connectedness framework was developed. Three-dimensional T1-weighted images in axial orientation were acquired through a 3D SPGR sequence by using a 1.5 T GE magnetic resonance scanner. Twenty-five normal images were analyzed using the proposed method, which involved adaptive fuzzy connectedness combined with confidence connectedness (AFCCC). After non-brain tissue removal and contrast enhancement, the seed point was selected manually, and confidence connectedness was used to perform an ROI update automatically. Both image intensity and local gradient were taken as image features in calculating the fuzzy affinity. Moreover, the weight of the features could be automatically adjusted. Thalamus, ventrointermedius (Vim), and subthalamic nucleus were successfully segmented. The results were evaluated with rules, such as similarity degree (SD), union overlap, and false positive. SD of thalamus segmentation reached values higher than 85%. The segmentation results were also compared with those achieved by the region growing and level set methods, respectively. Higher SD of the proposed method, especially in Vim, was achieved. The time cost using AFCCC was low, although it could achieve high accuracy. The proposed method is superior to the traditional fuzzy connectedness framework and involves reduced manual intervention in time saving.

Suppression of invasion in human U87 glioma cells by adenovirus-mediated co-transfer of TIMP-2 and PTEN gene.

TIMPs and PTEN are known to be inhibitors of the invasive activities of malignant glioma. But there has been no literature reported concerning the effect of combined gene transfer of these two genes on invasiveness of glioma. This study was designed to evaluate the effect of adenovirus-mediated in vitro gene transfer of tissue inhibitor of metalloproteinases-2 (TIMP-2) and phosphatase and tensin homology deleted on chromosome ten (PTEN) on invasion of human U87 glioma cells. The mRNA and protein expressions of TIMP-2 and PTEN in U87 cells infected with AdTIMP-2 and AdPTEN were determined by RT-PCR and Western blot, respectively. The relative activity of MMP-2 and MMP-9 were measured by Gelatin zymogram and invasion of U87 in vitro were detected using Boyden chamber. The number of invasion cell of U87, U87 infected with Ad-gal, AdPTEN, AdTIMP-2 and AdPTEN/TIMP-2 was 55.63+/-13.27, 48.27+/-14.75, 35.27+/-10.94, 27.37+/-12.81, and 19.17+/-5.45, respectively. In vitro invasiveness of glioma cells was significantly inhibited by infection with AdTIMP-2 and/or AdPTEN, which was not consistent with the change of MMPs activity. And in the combinated group, the inhibition effect was more remarkable than in single group. Our studies suggest that adenovirus-mediated combined TIMP-2 and PTEN gene therapy is possibly useful for anti-invasion therapy of malignant glioma.