Search Results (11)

Two accelerated magnetic resonance imaging (MRI) protocols for pediatric brain imaging, GOBrain and Deep Resolve Swift Brain, developed by Siemens Healthineers (Erlangen, Germany), were evaluated in a series of clinically relevant pediatric cases at 3 Tesla. Pediatric patients are particularly prone to motion, may be uncooperative, and often require sedation, especially in emergency settings. Consequently, there is a persistent clinical demand for fast brain MRI protocols that provide diagnostically sufficient image quality while minimizing examination time. Contemporary turbo spin-echo (TSE)-based clinical protocols commonly integrate parallel imaging (PI) and simultaneous multi-slice (SMS) techniques to achieve substantial reductions in scan time. Recent advances in three-dimensional volumetric encoding, compressed sensing, and deep learning (DL)-based reconstruction have further mitigated geometry-factor-related noise amplification, enabling higher acceleration factors (GOBrain). In parallel, echo-planar imaging (EPI) has emerged as a promising approach for ultrafast multi-contrast imaging. To overcome the limitations of single-shot EPI, a multi-shot EPI-based brain MRI protocol combined with the DL-based reconstruction method Deep Resolve Swift Brain has been developed. This approach leverages the efficiency of EPI while improving image quality. Using these accelerated protocols, a comprehensive diagnostic multi-contrast brain MRI examination, particularly suited to triage and emergency imaging, can be completed in minutes. This case overview, including therapy-related leukencephalopathy in acute lymphoblastic leukemia (ALL), a brain abscess, traumatic diffuse axonal injury (DAI), a posterior circulation infarction due to vertebral artery dissection, leuokostasis syndrome, and a posterior fossa tumor with obstructive hydrocephalus, demonstrates the potential clinical feasibility of both protocols in pediatric neuroimaging. Both protocols position them as supplementary options alongside established imaging protocols, while dedicated high-resolution protocols might remain necessary for subtle pathological findings, such as focal cortical dysplasia, and for neuronavigation until larger comparative studies are available. Full article

Background: In the last few decades, endoscopic endonasal approaches (EEA) have revolutionized surgical access to the sellar region and anterior cranial fossa (ACF). One technique, the endoscopic endonasal transethmoidal transcribriform approach (EETTA), offers distinct advantages over traditional open transcranial approaches, such as reduced morbidity, shorter hospital stays, faster recovery, and a reduced risk of neurological deficit due to less brain tissue manipulation. Methods: We present a comprehensive step-by-step description of the EETTA surgical technique, illustrated through four representative cases of varying pathologies treated at our institution. The anatomical boundaries—including the lamina papyracea, anterior and posterior ethmoidal arteries, and frontal sinus—and the surgical corridor are detailed alongside indications, technical nuances, limitations, and operative recommendations. Results: Four cases demonstrate the versatility of EETTA across diverse pathologies: two olfactory groove meningiomas (including one WHO grade 2 and one recurrent case with invasive skull base involvement), an esthesioneuroblastoma (ENB), and a recurrent inverted papilloma requiring combined transcranial and endoscopic resection. Near-total or gross-total resection was achieved in all cases. The indications, nuances, and limitations of this approach are discussed, along with tips for successful surgery. Conclusions: The EETTA represents an important minimally invasive option for ACF tumors extending into the nasal cavity, with midline involvement limited medially by the lamina papyracea. Success requires a thorough understanding of skull base anatomy, meticulous multilayer reconstruction techniques, and appropriate patient selection, based on the tumor location and lateral extension. While cerebrospinal fluid (CSF) leak remains the primary concern, contemporary techniques have substantially reduced this complication rate. Full article

Background and Clinical Significance: Adults suffering from cerebellar metastases are often at high risk for rapid deterioration of their neurological status because the posterior fossa has limited compliance and the location of these metastases are close to the brain stem and important cerebrospinal fluid (CSF) pathways. In this paper, we present a longitudinal, patient-centered report on the history of an elderly individual who suffered from cognitive comorbidities and experienced a sudden loss of function in her cerebellum. Our goal in reporting this case is to provide a comparison between the patient’s pre-operative and post-operative neurological examinations; the imaging studies she had before and after surgery; the surgical techniques utilized during her operation; and the outcome of her post-operative course in a way that will be helpful to other patients who have experienced a similar situation. Case Presentation: We report the case of an 80-year-old woman who initially presented with progressive ipsilateral limb-trunk ataxia, impaired smooth pursuit eye movement, and rebound nystagmus, but preserved pyramidal and sensory functions. Her quantitative bedside assessments included some of the components of the Scale for the Assessment and Rating of Ataxia (SARA), and a National Institute of Health Stroke Scale (NIHSS) score of 3. These findings indicated dysfunction of the left neocerebellar hemisphere and possible dentate nucleus involvement. The patient’s magnetic resonance imaging (MRI) results demonstrated an expansive mass with surrounding vasogenic edema and marked compression and narrowing of the exits of the fourth ventricle which placed the patient’s CSF pathways at significant risk of occlusion, while the aqueduct and inlets were patent. She then underwent a left lateral suboccipital craniectomy with controlled arachnoidal CSF release, preservation of venous drainage routes, subpial corticotomy oriented along the lines of the folia, stepwise internal debulking, and careful protection of the cerebellar peduncles and dentate nucleus. Dural reconstruction utilized a watertight pericranial graft to restore the cisternal compartments. Her post-operative intensive care unit (ICU) management emphasized optimal venous outflow, normoventilation, and early mobilization. Histopathology confirmed the presence of metastatic carcinoma, and staging suggested that the most likely source of the primary tumor was the lungs. Immediately post-operation, computed tomography (CT) imaging revealed a smooth resection cavity with open foramina of Magendie and Luschka, intact contours of the brain stem, and no evidence of bleeding or hydrocephalus. The patient’s neurological deficits, including dysmetria, scanning dysarthria, and ataxic gait, improved gradually during the first 48 h post-operatively. Upon discharge, the patient demonstrated an improvement in her limb-kinetic subscore on the International Cooperative Ataxia Rating Scale (ICARS) and demonstrated independent ambulation. At two weeks post-operation, CT imaging revealed decreasing edema and stable cavity size, and the patient’s modified Rankin scale had improved from 3 upon admission to 1. There were no episodes of CSF leakage, wound complications, or new cranial nerve deficits. A transient post-operative psychotic episode that was likely secondary to her underlying Alzheimer’s disease was managed successfully with short-course pharmacotherapy. Conclusions: The current case study demonstrates the value of anatomy-based microsurgical planning, preservation of venous and CSF pathways, and targeted peri-operative management to facilitate rapid recovery of function in older adults who suffer from cerebellar metastasis and cognitive comorbidities. The case also demonstrates the importance of early multidisciplinary collaboration to allow for timely initiation of both adjuvant stereotactic radiosurgery and molecularly informed systemic therapy. Full article

Background/Objectives: The management of Chiari malformations (CMs) remains a clinical challenge and a topic of great controversy. Results may vary between children and adults. The purpose of the current single-center study is to critically assess the one-year surgical outcomes of a cohort of 110 children with CM-1 or CM-1.5 who were treated using “posterior fossa reconstruction” (PFR), a surgical technique described in 1994 that has since been used in both adults and children. We also review the literature and discuss the possible causes of the drawbacks and pitfalls in children in whom PFR was ineffective in controlling the disease. Methods: The present cohort was selected from a prospective registry of adults and children with CMs collected since 2006. Patients included in this study were selected from a group of children with CMs who were operated on in our Pediatric Neurosurgical Unit between 1 January 2007 and 31 November 2023. Surgical outcome was defined based on clinical and neuroradiological results as very good, good, or bad. Results: The mean age of our child cohort was 9.9 ± 4.7 years, with 54 girls (49%) and 56 boys (51%). Sixty-six children had CM-1 (60%) while forty-four had CM-1.5 (40%). Following surgery, there was no neurological worsening or death among the children. Most children (70%) had an uneventful recovery and were discharged home on average one week after surgery. However, in 33 children (30%), we recorded at least one postoperative adverse event. Aseptic meningitis syndrome was the most frequent adverse event (n = 25, 22.7%). The final surgical outcome was evaluated one year after PFR by using both clinical and neuroradiological results. The one-year surgical outcome was excellent in 101 children (91.9%), good in 5 (4.5%), and bad in 4 (3.6%). Conclusions: PFR significantly enlarges the volume of the posterior fossa and recreates a CSF environment that generates buoyancy of the cerebellum, with a high percentage of excellent and good clinical results evaluated one year post-surgery. Full article

Advances in technology, instrumentation, and reconstruction have paved the way for extended endoscopic approaches to skull base tumors. In the sagittal plane, the endonasal approach may safely access pathologies from the frontal sinus to the craniocervical junction in the sagittal plane, the petrous apex in the coronal plane, and extend posteriorly to the clivus and posterior cranial fossa. This review article describes these modular extended endoscopic approaches, along with crucial anatomic considerations, illustrative cases, and practical operative pearls. Full article

The landscape of cranial base surgery has undergone monumental transformations over the past several decades. This article serves as a comprehensive survey, detailing both the historical and current techniques and technologies that have propelled this field into an era of unprecedented capabilities and sophistication. In the prologue, we traverse the historical evolution from rudimentary interventions to the state-of-the-art neurosurgical methodologies that define today’s practice. Subsequent sections delve into the anatomical complexities of the anterior, middle, and posterior cranial fossa, shedding light on the intricacies that dictate surgical approaches. In a section dedicated to advanced techniques and modalities, we explore cutting-edge evolutions in minimally invasive procedures, pituitary surgery, and cranial base reconstruction. Here, we highlight the seamless integration of endocrinology, biomaterial science, and engineering into neurosurgical craftsmanship. The article emphasizes the paradigm shift towards “Functionally” Guided Surgery facilitated by intraoperative neuromonitoring. We explore its historical origins, current technologies, and its invaluable role in tailoring surgical interventions across diverse pathologies. Additionally, the digital era’s contributions to cranial base surgery are examined. This includes breakthroughs in endoscopic technology, robotics, augmented reality, and the potential of machine learning and AI-assisted diagnostic and surgical planning. The discussion extends to radiosurgery and radiotherapy, focusing on the harmonization of precision and efficacy through advanced modalities such as Gamma Knife and CyberKnife. The article also evaluates newer protocols that optimize tumor control while preserving neural structures. In acknowledging the holistic nature of cranial base surgery, we advocate for an interdisciplinary approach. The ecosystem of this surgical field is presented as an amalgamation of various medical disciplines, including neurology, radiology, oncology, and rehabilitation, and is further enriched by insights from patient narratives and quality-of-life metrics. The epilogue contemplates future challenges and opportunities, pinpointing potential breakthroughs in stem cell research, regenerative medicine, and genomic tailoring. Ultimately, the article reaffirms the ethos of continuous learning, global collaboration, and patient-first principles, projecting an optimistic trajectory for the field of cranial base surgery in the coming decade. Full article

This exploratory retrospective study aims to quantitatively compare the image quality of unenhanced brain computed tomography (CT) reconstructed with an iterative (AIDR-3D) and a deep learning-based (AiCE) reconstruction algorithm. After a preliminary phantom study, AIDR-3D and AiCE reconstructions (0.5 mm thickness) of 100 consecutive brain CTs acquired in the emergency setting on the same 320-detector row CT scanner were retrospectively analyzed, calculating image noise reduction attributable to the AiCE algorithm, artifact indexes in the posterior cranial fossa, and contrast-to-noise ratios (CNRs) at the cortical and thalamic levels. In the phantom study, the spatial resolution of the two datasets proved to be comparable; conversely, AIDR-3D reconstructions showed a broader noise pattern. In the human study, median image noise was lower with AiCE compared to AIDR-3D (4.7 vs. 5.3, p < 0.001, median 19.6% noise reduction), whereas AIDR-3D yielded a lower artifact index than AiCE (7.5 vs. 8.4, p < 0.001). AiCE also showed higher median CNRs at the cortical (2.5 vs. 1.8, p < 0.001) and thalamic levels (2.8 vs. 1.7, p < 0.001). These results highlight how image quality improvements granted by deep learning-based (AiCE) and iterative (AIDR-3D) image reconstruction algorithms vary according to different brain areas. Full article

In this study, we assess image quality in computed tomography scans reconstructed via DLIR (Deep Learning Image Reconstruction) and compare it with iterative reconstruction ASIR-V (Adaptive Statistical Iterative Reconstruction) in CT (computed tomography) scans of the head. The CT scans of 109 patients were subjected to both objective and subjective evaluation of image quality. The objective evaluation was based on the SNR (signal-to-noise ratio) and CNR (contrast-to-noise ratio) of the brain’s gray and white matter. The regions of interest for our study were set in the BGA (basal ganglia area) and PCF (posterior cranial fossa). Simultaneously, a subjective assessment of image quality, based on brain structure visibility, was conducted by experienced radiologists. In the assessed scans, we obtained up to a 54% increase in SNR for gray matter and a 60% increase for white matter using DLIR in comparison to ASIR-V. Moreover, we achieved a CNR increment of 58% in the BGA structures and 50% in the PCF. In the subjective assessment of the obtained images, DLIR had a mean rating score of 2.8, compared to the mean score of 2.6 for ASIR-V images. In conclusion, DLIR shows improved image quality compared to the standard iterative reconstruction of CT images of the head. Full article

The phylogenetic relationships of turtles (Testudines) challenge cladistics by demonstrating the inherent weaknesses of this non-Darwinian method of phylogenic reconstruction. Recent cladistic analyses have identified sauropterygians as the closest relatives of turtles and even at least one sauropterygian, Pappochelys, as a turtle. These findings are largely based on the convergence of several characteristics associated with environmental adaptation, including the relative lengths of phalanges, dense gastralia placement (assumed proto-plastron), and a well-defined intertrochanteric fossa. A lack of failure testing to identify such convergence is important in the analysis of unusual taxa because it can force a taxon into the in-group as a methodological artifact, as with the cladistic placement of Eunotosaurus within Testudines. Eunotosaurus was not placed in a wider vertebrate phylogeny, which led to its identification as a basal member of Caseidae. The characteristics shared by caseids and Testudines, including their relative head-to-body size, posterior jaw articulation, and reduced number of dorsal ribs and vertebrae, contributed to this mistake. Late Triassic Chinlechelys provides a useful window into these varied cladistic problems due to anatomical convergence. It demonstrates an intermediate step between a carapace with neighboring ribs and a carapace fused with ribs. This earlier state lacked the organizing role of the ribs in the carapace and had multiple rows of costals (dorsal osteoderms) arranged at an angle to the ribs, which is a condition only known in some pareiasaurs. This fits with an evo-devo model of gradual change creating a new structure (a carapace), which was followed by adaptive radiation filling the new niches opened by that structure. Full article

In 2021, the first clinical photon-counting CT (PCCT) was introduced. The purpose of this study is to evaluate the image quality of polyenergetic and virtual monoenergetic reconstructions in unenhanced PCCTs of the head. A total of 49 consecutive patients with unenhanced PCCTs of the head were retrospectively included. The signals ± standard deviations of the gray and white matter were measured at three different locations in axial slices, and a measure of the artifacts below the cranial calvaria and in the posterior fossa between the petrous bones was also obtained. The signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) were calculated for all reconstructions. In terms of the SNRs and CNRs, the polyenergetic reconstruction is superior to all virtual monoenergetic reconstructions (p < 0.001). In the MERs, the highest SNR is found in the 70 keV MER, and the highest CNR is in the 65 keV MER. In terms of artifacts below the cranial calvaria and in the posterior fossa, certain MERs are superior to polyenergetic reconstruction (p < 0.001). The PCCT provided excellent image contrast and low-noise profiles for the differentiation of the grey and white matter. Only the artifacts below the calvarium and in the posterior fossa still underperform, which is attributable to the lack of an artifact reduction algorithm in image postprocessing. It is conceivable that the usual improvements in image postprocessing, especially with regard to glaring artifacts, will lead to further improvements in image quality. Full article

Tumors arising from the posterior hard palate or posterolateral maxilla may extend to involve the infratemporal fossa (ITF). Resection of these tumors results in infrastructural maxillectomy with ITF defects. In this study, we describe the use of an adipofascial anterolateral thigh flap (ALT) specifically for such defects. This case series includes four patients who underwent an infrastructure maxillectomy with ITF clearance and the resultant defects were reconstructed using adipofascial anterolateral thigh flaps. The complications as well as the functional outcomes were assessed. This study included patients with lesions involving the hard palate, posterolateral part of maxilla with extension into the ITF. The mean flap dimension was 150 cm² (range, 120–180 cm²). All flaps were harvested based on a single perforator. The flap was used to obliterate the ITF defect and also to achieve oroantral separation. All flaps mucosalized well within 6 weeks. All patients were on oral diet and had adequate mouth opening. There were no donor-site complications. Adipofascial ALT is an excellent choice for infrastructural maxillectomy defects with ITF extension. The intraoral part got mucosalized well and provided a smooth and taut surface. A large adipofascial tissue flap helps obliterate the ITF, thus minimizing complications. Full article