Preoperative prediction of CNS WHO grade and tumour aggressiveness in intracranial meningioma based on radiomics and structured semantics.

Preoperative identification of intracranial meningiomas with aggressive behaviour may help in choosing the optimal treatment strategy. Radiomics is emerging as a powerful diagnostic tool with potential applications in patient risk stratification. In this study, we aimed to compare the predictive value of conventional, semantic based and radiomic analyses to determine CNS WHO grade and early tumour relapse in intracranial meningiomas.

Invasiveness of decompression surgery affects modeled lumbar spine kinetics in patients with degenerative spondylolisthesis.

The surgical treatment of degenerative spondylolisthesis with accompanying spinal stenosis focuses mainly on decompression of the spinal canal with or without additional fusion by means of a dorsal spondylodesis. Currently, one main decision criterion for additional fusion is the presence of instability in flexion and extension X-rays. In cases of mild and stable spondylolisthesis, the optimal treatment remains a subject of ongoing debate.

Beyond Glioma: The Utility of Radiomic Analysis for Non-Glial Intracranial Tumors.

The field of radiomics is rapidly expanding and gaining a valuable role in neuro-oncology. The possibilities related to the use of radiomic analysis, such as distinguishing types of malignancies, predicting tumor grade, determining the presence of particular molecular markers, consistency, therapy response, and prognosis, can considerably influence decision-making in medicine in the near future. Even though the main focus of radiomic analyses has been on glial CNS tumors, studies on other intracranial tumors have shown encouraging results.

Quantitative assessment and localization of the hollowing of the temple after craniectomy and cranioplasty-The frontozygomatic shadow.

Background: After cranioplasty, in many cases a not negligible soft tissue defect remains in the temporozygomatical area, also referred to as a hollowing defect of the temple.

Objective: To assess the precise localization and volume of the hollowing defect, to optimize future cranioplasties.

Methods: CT data of patients who received craniectomy and conventional CAD cranioplasty in our institution between 2012 and 2018 were analyzed.

Load Distribution in the Lumbar Spine During Modeled Compression Depends on Lordosis.

Excessive or incorrect loading of lumbar spinal structures is commonly assumed as one of the factors to accelerate degenerative processes, which may lead to lower back pain. Accordingly, the mechanics of the spine under medical conditions, such as scoliosis or spondylolisthesis, is well-investigated. Treatments via both conventional therapy and surgical methods alike aim at restoring a "healthy" (or at least pain-free) load distribution.

Analysis of Cerebral Vasospasm in a Murine Model of Subarachnoid Hemorrhage with High Frequency Transcranial Duplex Ultrasound.

Cerebral vasospasm that occurs in the weeks after subarachnoid hemorrhage, a type of hemorrhagic stroke, contributes to delayed cerebral ischemia. A problem encountered in experimental studies using murine models of SAH is that methods for in vivo monitoring of cerebral vasospasm in mice are lacking. Here, we demonstrate the application of high frequency ultrasound to perform transcranial Duplex sonography examinations on mice.

Caliper navigation for craniotomy planning of convexity targets.

Introduction: A technique to localize a radiological target on the head convexity fast and with acceptable precision is sufficient for surgeries of superficial intracranial lesions, and of help in the setting of emergency surgery, computer navigation breakdown, limited resources and education. We present a caliper technique based on fundamental geometry, with inexpensive and globally available tools (conventional CT or MRI image viewer, calculator, caliper).

Methods: The distances of the radiological target from two landmarks (nasion and porus acusticus externus) are assessed with an image viewer and Pythagoras' theorem.

Correlation of cardiac function and cerebral perfusion in a murine model of subarachnoid hemorrhage.

Cerebral hypoperfusion is a key factor for determining the outcome after subarachnoid hemorrhage (SAH). A subset of SAH patients develop neurogenic stress cardiomyopathy (NSC), but it is unclear to what extent cerebral hypoperfusion is influenced by cardiac dysfunction after SAH. The aims of this study were to examine the association between cardiac function and cerebral perfusion in a murine model of SAH and to identify electrocardiographic and echocardiographic signs indicative of NSC.

Muscle-driven and torque-driven centrodes during modeled flexion of individual lumbar spines are disparate.

Lumbar spine biomechanics during the forward-bending of the upper body (flexion) are well investigated by both in vivo and in vitro experiments. In both cases, the experimentally observed relative motion of vertebral bodies can be used to calculate the instantaneous center of rotation (ICR). The timely evolution of the ICR, the centrode, is widely utilized for validating computer models and is thought to serve as a criterion for distinguishing healthy and degenerative motion patterns.

Automated Grading of Cerebral Vasospasm to Standardize Computed Tomography Angiography Examinations After Subarachnoid Hemorrhage.

Computed tomography angiography (CTA) is frequently used with computed tomography perfusion imaging (CTP) to evaluate whether endovascular vasospasm treatment is indicated for subarachnoid hemorrhage patients with delayed cerebral ischemia. However, objective parameters for CTA evaluation are lacking. In this study, we used an automated, investigator-independent, digital method to detect vasospasm, and we evaluated whether the method could predict the need for subsequent endovascular vasospasm treatment.

Multicolor 3D Printing of Complex Intracranial Tumors in Neurosurgery.

Three-dimensional (3D) printing technologies offer the possibility of visualizing patient-specific pathologies in a physical model of correct dimensions. The model can be used for planning and simulating critical steps of a surgical approach. Therefore, it is important that anatomical structures such as blood vessels inside a tumor can be printed to be colored not only on their surface, but throughout their whole volume.

Neutrophils mediate early cerebral cortical hypoperfusion in a murine model of subarachnoid haemorrhage.

Cerebral hypoperfusion in the first hours after subarachnoid haemorrhage (SAH) is a major determinant of poor neurological outcome. However, the underlying pathophysiology is only partly understood. Here we induced neutropenia in C57BL/6N mice by anti-Ly6G antibody injection, induced SAH by endovascular filament perforation, and analysed cerebral cortical perfusion with laser SPECKLE contrast imaging to investigate the role of neutrophils in mediating cerebral hypoperfusion during the first 24 h post-SAH.

A Volumetric Method for Quantification of Cerebral Vasospasm in a Murine Model of Subarachnoid Hemorrhage.

Subarachnoid hemorrhage (SAH) is a subtype of hemorrhagic stroke. Cerebral vasospasm that occurs in the aftermath of the bleeding is an important factor determining patient outcome and is therefore frequently taken as a study endpoint. However, in small animal studies on SAH, quantification of cerebral vasospasm is a major challenge.

Volumetric analysis of intracranial vessels: a novel tool for evaluation of cerebral vasospasm.

Purpose: Together with other diagnostic modalities, computed tomography angiography (CTA) is commonly used to indicate endovascular vasospasm treatment after subarachnoid hemorrhage (SAH), despite the fact that objective, user-independent parameters for evaluation of CTA are lacking. This exploratory study was designed to investigate whether quantification of vasospasm by automated volumetric analysis of the middle cerebral artery M1 segment from CTA data could be used as an objective parameter to indicate endovascular vasospasm treatment.

Methods: We retrospectively identified SAH patients who underwent transcranial Doppler sonography (TCD), CTA, and CT perfusion (CTP), with or without subsequent endovascular treatment.

Large Vessel Vasospasm Is Not Associated with Cerebral Cortical Hypoperfusion in a Murine Model of Subarachnoid Hemorrhage.

Clinical studies on subarachnoid hemorrhage (SAH) have shown discrepancies between large vessel vasospasm, cerebral perfusion, and clinical outcome. We set out to analyze the contribution of large vessel vasospasm to impaired cerebral perfusion and neurological impairment in a murine model of SAH. SAH was induced in C57BL/6 mice by endovascular filament perforation.

Navigation and Image Injection for Control of Bone Removal and Osteotomy Planes in Spine Surgery.

Background And Importance: In contrast to cranial interventions, neuronavigation in spinal surgery is used in few applications, not tapping into its full technological potential. We have developed a method to preoperatively create virtual resection planes and volumes for spinal osteotomies and export 3-D operation plans to a navigation system controlling intraoperative visualization using a surgical microscope's head-up display. The method was developed using a Sawbone ® model of the lumbar spine, demonstrating feasibility with high precision.

Three-dimensional Cross-Platform Planning for Complex Spinal Procedures: A New Method Adaptive to Different Navigation Systems.

Study Design: A feasibility study.

Objective: To develop a method based on the DICOM standard which transfers complex 3-dimensional (3D) trajectories and objects from external planning software to any navigation system for planning and intraoperative guidance of complex spinal procedures.

Summary Of Background Data: There have been many reports about navigation systems with embedded planning solutions but only few on how to transfer planning data generated in external software.

A segmentation-based volumetric approach to localize and quantify cerebral vasospasm based on tomographic imaging data.

Introduction: Quantification of cerebral vasospasm after subarachnoid hemorrhage (SAH) is crucial in animal studies as well as clinical routine. We have developed a method for computer-based volumetric assessment of intracranial blood vessels from cross-sectional imaging data. Here we demonstrate the quantification of vasospasm from micro computed tomography (micro-CT) data in a rodent SAH model and the transferability of the volumetric approach to clinical data.

A Modified Microsurgical Endoscopic-Assisted Transpedicular Corpectomy of the Thoracic Spine Based on Virtual 3-Dimensional Planning.

Background And Objective: The main difficulties of transpedicular corpectomies are lack of space for vertebral body replacement in the neighborhood of critical structures, the necessity for sacrifice of nerve roots in the thoracic spine. and the extent of hemorrhage due to venous epidural bleeding. We present a modified technique of transpedicular corpectomy by using an endoscopic-assisted microsurgical technique performed through a single posterior approach.

Computer simulation and image guidance for individualised dynamic spinal stabilization.

Purpose: Dynamic implants for the human spine are used to re-establish regular segmental motion. However, the results have often been unsatisfactory and complications such as screw loosening are common. Individualisation of appliances and precision implantation are needed to improve the outcome of this procedure.