Straight Sinus Research Articles

Dural Venous Sinus Variations Observed in Magnetic Resonance Venography at a Tertiary Care Hospital: An Observational Study

Introduction: The dural venous system, composed of various sinuses, plays a crucial role in draining deoxygenated blood from the central nervous system. Understanding its anatomical variations is essential to differentiate it from pathological conditions like cerebral venous sinus thrombosis. This study aims to evaluate the anatomical variations of the dural venous sinuses using Magnetic Resonance Venography.Methods: An observational, cross-section study was performed in the Department of Radiology from September 2023 to March 2024 after the approval by the Institutional Review Committee (Reference number: 149/080/081(6-11)E2). Magnetic Resonance Venography of 109 adult patients was performed using a 1.5 Tesla MRI scanner. Diameters of the superior sagittal sinus, straight sinus, and transverse sinuses were measured. Variations in transverse sinuses, straight sinus, and confluence were categorized and analyzed. Results: The study included 52 (47.70%) male and 57 (52.30%) female, with median age of 42 (IQR: 30.5 - 56) years. The superior sagittal sinus had the diameter of 6.4±1 mm. Symmetric transverse sinus variant seen was in 80 (73.39%) patients, and left transverse sinus hypoplasia was seen in 20 (18.35%) patients. Variations in the straight sinus and confluence were also documented with a true confluence (type III) was seen in 71 (65.10%) patients.Conclusions: Anatomical variations of the dural venous sinuses as observed in 1.5 Tesla MRI was quite common.

Measurement of cerebral venous oxygenation with quantitative susceptibility mapping after subarachnoid hemorrhage: A pilot study.

We measured cerebral venous oxygenation after aneurysmal subarachnoid hemorrhage (aSAH) using quantitative susceptibility mapping (QSM) to explore its relationship with cognitive function. Twenty participants, including 10 patients with aSAH and 10 healthy volunteers as the control group, were included. Patients with aSAH were evaluated at 2days, 3weeks, and 6months after aSAH. Each participant underwent magnetic resonance imaging and completed the Montreal Cognitive Assessment (MoCA) at baseline, midpoint, and endpoint. QSM was used to determine the magnetic susceptibility of the cerebral veins. Furthermore, the relationship between MoCA and oxygen saturation in the cerebral veins was examined. The first scans of the cerebral veins and straight sinus susceptibility were considerably more significant in the aSAH group than in the healthy control group. At the 6-month follow-up, the mean oxygen saturation steadily increased in the aSAH group. Cerebral venous oxygen saturation was moderately correlated with MoCA (r = 0.5319, P = .0025). QSM can be used to measure changes in cerebral venous oxygenation levels in patients with aSAH. During the acute phase of aSAH, there is a reduction in the oxygen saturation in the cerebral veins, and the shift in oxygen saturation levels may correlate with cognitive outcomes in patients with aSAH.

Cerebral Venous Thrombosis in a Young Adult: A Case Report Highlighting Thrombophilia and Epilepsy Management

Cerebral venous thrombosis (CVT) is a rare but serious condition that can lead to significant neurological complications if not promptly diagnosed and treated. This case report describes a 23-year-old male with a history of epilepsy, managed with sodium valproate, who presented with a sudden, severe headache and visual disturbances. Imaging revealed a linear filling defect in the straight sinus, consistent with CVT. Further investigation uncovered deficiencies in protein S and C, indicating an underlying thrombophilic condition. The patient was successfully treated with anticoagulation therapy, initially with enoxaparin followed by oral apixaban, resulting in the complete resolution of symptoms. This case shows the importance of considering thrombophilia in patients with CVT, especially those with a history of epilepsy, and demonstrates the effectiveness of early intervention with anticoagulants in achieving positive outcomes.

DC-CRP: Deep Cerebral Venous Thrombosis, Clinicoradiological Profile, and Treatment Outcome in Indian Population-A Tertiary Care Experience.

Deep cerebral venous thrombosis (DCVT) is an uncommon cause of stroke with diverse predisposing factors, clinical presentations, imaging findings, and functional outcomes, which makes the diagnosis of DCVT even more challenging. Retrospective observational study (December 2018 to January 2023). Cases with imaging data suggestive of DCVT were included. The neuroradiological assessment was performed using multimodality imaging to determine the location of parenchymal changes and the number of deep veins involved in isolation or with the superficial dural venous system. Clinical variables were tabulated. Of the 206 cases with CVT in the study period, 27 had DCVT (13.1%), of which four (14.8%) had isolated DCVT (male-to-female ratio 13:14; mean age = 33.4 years). Hyperhomocysteinemia (n = 11) is the most common risk factor associated with it. The most common presentations were headaches (n = 27) and focal motor deficits (n = 13). Raised intracranial tension (ICT) was present in almost half of the study population (n = 14). Mean and median modified Rankins score (mRS) at the time of discharge were 2.0 and 1, respectively. The most common deep vein involved was the straight sinus (SS) (n = 25), followed by the internal cerebral vein (n = 23). The mean and median mRS after 3 months from discharge were 0.3 and 0, respectively. A knowledge of diverse clinical presentations in DCVT, its neurovascular anatomy, and imaging characteristics with prompt diagnosis and timely interventions can assist in attenuating the risk of acute complications and long-term sequelae. Extensive deep grey matter involvement in DCVT is associated with neurological manifestations like altered sensorium and motor deficits, with increased severity of illness as measured by the mRS score.

How I do it: surgical ligation of posteromedial tentorial dural arteriovenous fistulas.

Tentorial dural arteriovenous fistulas (dAVFs) are categorized based on venous drainage and location. Althoughtheir angioarchitecture may initially appear intimidating, once "decodified," treatment is straightforward. Posteromedial tentorial dAVFs have an arterialized draining vein that emanates from the inferior tentorium along the posterior third of the straight sinus, just slightly off the midline. With the aid of anatomical dissections, intraoperative photos, and operative videos, we outline the key steps for surgical treatment of posteromedial tentorial dAVFs. Posteromedial tentorial dAVFs constitute a precise and well-defined subtype of tentorial dAVF for which surgical ligation has an important role.

A rare case of chronic headache

Abstract Cerebral venous thrombosis (CVT) is a relatively uncommon and rare condition worldwide, affecting approximately 1 in 100,000 individuals annually and comprising about 0.5% of all strokes. It is more prevalent in women of childbearing age due to hypercoagulable states. We present a case report of a 19 years old female exhibiting symptoms, including headache, occasionally associated vomiting, blurring of vision and one generalised seizure. On general examination and neurological, there were no significant abnormality found, Fundoscopy revealed blurred disc margins and the presence of papilledema. An emergency non-contrast computed tomography (NCCT) scan of the brain showed normal findings. Subsequently, a magnetic resonance imaging (MRI) scan of the brain indicated partial loss of flow void in the posterior part of the superior sagittal sinus and straight sinus, along with the formation of collateral channels, suggestive of possible subacute dural sinus thrombosis. Additionally, a contrast-enhanced MRI (CEMRI) scan with MR venogram showed filling defects in the posterior part of the superior sagittal sinus and straight sinus, with non-visualization of the left transverse sinus, indicative of subacute to chronic dural venous thrombosis, Beta 2 glycoprotein IgM and Cardiolipin IgM were positive and titres were high. This case with history of headache for 4 years underscores the need for early diagnosis, which could have alleviated suffering and further prevent grave consequences, with an insight to such problems and accessibility to high end imaging diagnosis tools for early recognition and management.

Comparing Vascular Morphology and Hemodynamics in Patients with Vein of Galen Malformations Using Intracranial 4D Flow MRI.

Vein of Galen malformation (VOGM) is the most common congenital cerebrovascular malformation, and many patients have high mortality rates and poor cognitive outcomes. Quantitative diagnostic tools are needed to improve clinical outcomes, and the purpose of this study was to characterize intracranial blood flow in VOGM using quantitative 4D flow MRI. A prospective study of children with VOGM was conducted by acquiring 4D flow MRI to quantify total blood inflow to the brain, flow in the pathologic falcine sinus, and flow in the superior sagittal sinus. Linear regression was used to test the relationships between these flows and age, clinical status, and the mediolateral diameter of the outflow tract of the lesion through the falcine or straight sinus diameter, which is a known morphologic prognostic metric. In all 11 subjects (mean age, 22 [SD,17 ] weeks), total blood flow to the brain always exceeded normal levels (mean, 1063 [SD, 403] mL/minute). Significant correlations were observed between falcine sinus flow and the mediolateral diameter of the straight or falcine sinus, the posterior cerebral artery/MCA flow ratio and age at scanning, and superior sagittal sinus flow proximal to malformation inflow and age at scanning. Using 4D flow MRI, we established the hemodynamic underpinnings of the mediolateral diameter of the straight or falcine sinus and investigated metrics representing parenchymal venous drainage that could be used to monitor the normalization of hemodynamics during embolization therapy.

Chordae Willisii of the dural sinuses: an anatomical study using magnetic resonance imaging.

The chordae Willisii (CWs), trabecular projections into the lumen of the dural sinuses, are not well understood. We aimed to explore them using magnetic resonance imaging (MRI). Eighty-five patients underwent volumetric contrast-enhanced MRI, while another 30 underwent a fluid-attenuated inversion recovery (FLAIR) sequence in the coronal section. The CWs were detected as linear filling defects lying in the dural sinuses, adjacent to the surrounding dura mater. They were found in the superior sagittal sinus (SSS) in 68.2% of the patients, most frequently in the middle third, with laminar appearance. In 27.1% of the patients, the CWs divided the SSS lumen into separate channels. The CWs were identified in the transverse sinus, transverse-sigmoid sinus junctional area and sigmoid sinus, and straight sinus in 54.1, 47.1, and 8.2%, respectively. On the FLAIR images, dural septi partially dividing the SSS lumen were identified in all patients. In addition, in 73.3% of the patients, fine linear structures were observed in the lumen with inconstant arrangements. The CWs may be constant structures distributed over the lumen of the intracranial dural sinuses. Contrast-enhanced MRI may be useful for detecting laminar CWs. The FLAIR sequence may be advantageous for delineating the dural septi projecting into the lumen of the dural sinuses.

Assessment of cerebral venous sinus: Anatomical and functional diagnostic performance of three-dimensional reconstruction models based on venous sinus MRI and CT images

Venous sinus stenosis is commonly observed in patients presenting with pulsatile tinnitus (PT). While magnetic resonance imaging (MRI) and computed tomography (CT) are commonly used for assessing venous sinus geometries, the preferred modality remains unclear. In this study, we reconstructed the three-dimensional (3D) geometries of the venous sinus using MRI and CT imaging data from 20 PT patients. We conducted comparisons of the anatomical features of the venous sinus through case-wise analysis and anatomic geometrical parameter-wise analysis. Our findings indicate that by taking the geometries from CT as a reference, MRI could provide a better illustration of venous structure, primarily due to a stronger flow signal concentrated in the vascular tree. We observed high agreements in anatomic parameters measured from 3D geometries reconstructed based on CT and MRI in 19 out of 20 cases. Notably, the cross-sectional area of the sinus and segment length displayed the highest consistency, with a mean difference of -5.01% and 6.5% between modalities, respectively. In addition, we noticed that 55% of cases exhibited consistency in analyzing the confluence of the sinus, while variants of connectivity and collateral branching were observed between CT and MRI. Importantly, CT-based geometric reconstruction provided better detail of inflow side branches in the straight sinus, whereas MRI preserved more side branches of outflow in the downstream sinus. It is important to note that CT-based evaluation may be affected by the bone structures surrounding the venous sinus, whereas MRI-based evaluation focuses on blood flow to the segments, potentially indicating both anatomical and functional abnormalities.

Basal Vein of Rosenthal, Vein of Galen, and Straight Sinus

The basal vein of Rosenthal, the vein of Galen, and the straight sinus are important venous communication routes connecting the deep, superficial, and dural sinuses. The basal vein is divided into three parts since it originates secondarily from three different areas and its venous areas are diverse. However, care should be taken because disconnection between these segments causes variations that change the venous flow path. Endovascular treatment warrants a proper understanding of this anatomical area and requires consideration of vascular occlusion and venous drainage changes.

Posterior Interhemispheric-Transtentorial Approach for Resection of an Arteriovenous Malformation of the Superior Medullary Velum and Fourth Ventricle: 2-Dimensional Operative Video.

Brain arteriovenous malformations (AVMs) of the fourth ventricle represent a rare subtype associated with an aggressive natural course.1,2 In this case, a woman in her early 50s presented with dizziness. An AVM was diagnosed in the left superior cerebellar peduncle extending into the fourth ventricle. The AVM was supplied by superior cerebellar artery branches and classified as a Spetzler-Martin grade III and a Lawton-Young grade III, with a supplemented grade of 6.3,4 Being a single case report, institutional review board approval was not needed. Patient consent was obtained. The lesion was accessed through a torcular craniotomy and posterior interhemispheric-transtentorial approach, employing gravity to naturally retract the parietooccipital lobe.5-7 Dissection continued into the quadrigeminal and ambient cisterns, where the tentorium was incised parallelling the straight sinus to reach the superior vermis. Partial resection of the lingual and central lobules of the vermis facilitated access to the superior medullary velum. The superior cerebellar artery feeders were divided and followed to the superior cerebellar peduncle and through the superior medullary vellum. A vertical incision in the superior medullary velum facilitated entry into the fourth ventricle, where the AVM nidus was dissected circumferentially and resected en bloc. Intraoperative indocyanine green videoangiography and postoperative digital subtraction angiography confirmed complete obliteration of the AVM. After surgery, the patient experienced mild ataxia, but motor symptoms greatly improved during 3-month follow-up. This video illustrates resection of a complex fourth ventricular AVM through a posterior interhemispheric-transtentorial approach, highlighting pivotal considerations of patient positioning and approach selection to optimize treatment outcome for complex posterior fossa AVM resection.

Vein of Galen aneurysmal malformation: does size affect outcome?

PurposeTo validate a semiautomated method for segmenting vein of Galen aneurysmal malformations (VGAM) and to assess the relationship between VGAM volume and other angioarchitectural features, cardiological findings, and outcomes.MethodsIn this retrospective study, we selected all subjects with VGAM admitted to the Gaslini Children’s Hospital between 2009 and 2022. Clinical data were retrieved from electronic charts. We compared 3D-Slicer segmented VGAM volumes obtained by two independent observers using phase-contrast MR venography to those obtained with manual measurements performed on T2-weighted images. The relationship between VGAM volumes and clinical and neuroimaging features was then explored.ResultsForty-three subjects with VGAM (22 males, mean age 6.56 days) were included in the study. Manual and semiautomated VGAM volumes were well correlated for both readers (r = 0.86 and 0.82, respectively). Regarding reproducibility, the inter-rater interclass correlation coefficients were 0.885 for the manual method and 0.992 for the semiautomated method (p < 0.001). The standard error for repeated measures was lower for the semiautomated method (0.04 versus 0.40 of manual method). Higher VGAM volume was associated with superior sagittal sinus narrowing, jugular bulb stenosis, and aqueductal stenosis (p < 0.05). A weak correlation was found between VGAM volume and straight sinus dilatation (r = 0.331) and superior sagittal sinus index (r = − 0.325). No significant associations were found with cardiac findings, post-embolization complications, and outcome (p > 0.05).ConclusionsSemiautomated VGAM volumetry is feasible and reliable with improved reproducibility compared to the manual method. VGAM volume is not a prognostic factor for clinical outcome, but it is related to other venous findings with potential hemodynamic effects.

185 Deuterium MRI for CSF Studies in Normal and Hydrocephalic Rats

INTRODUCTION: The recent characterization of the glymphatic system has revived interest in the interaction of cerebrospinal fluid (CSF) with brain tissue via perivascular spaces. Traditional CSF tracers, such as gadolinium and iohexal, are large molecules that do not cross the blood brain barrier (BBB). The primary component of CSF, however, is water, which is BBB permeable. METHODS: Eight adult male rats underwent cisterna magna catheterization for intrathecal infusion. Brain MR images were obtained in a 7 tesla small-animal MRI system. Temporal T1-weighted images (T1WI) were obtained before, during, and after intrathecal infusion of D2O. Five rats then underwent ventricular kaolin injection for induction of hydrocephalus, after which repeat imaging with intrathecal D2O infusion was performed. RESULTS: Intrathecal deuterium infusion produced consistent changes on MRI imaging. Because conventional MRI does not sense deuterium, the T1WI showed a loss in proton signal with D2O infusion. Rapid D2O uptake of &lt;2.5 minutes was noted in CSF spaces, brain tissue, and saggital and straight venous sinuses. CONCLUSIONS: Use of deuterium as an intrathecal contrast agent provides a physiologically realistic model of CSF behavior. Efforts are ongoing to quantify the relationship between MRI signal loss and deuterium tissue concentration for comparative analysis between healthy and hydrocephalic rats. The loss of MRI signal in the straight sinus after intrathecal infusion implicates the deep venous system in the clearance of CSF, suggesting that CSF is reabsorbed into the venous system via the brain tissue itself. Because traditional CSF tracers do not cross the BBB, the role of the brain tissue in the reabsorption of CSF has been overlooked.

Eclipse balloon-assisted straight sinus thrombectomy: A novel technique.

Cerebral venous sinus thrombosis comprises 0.5% of all strokes and usually affects young adults. Straight sinus involvement is relatively rare, and it is associated with poor prognosis. Intravenous anticoagulation is considered the first line of treatment. Endovascular approaches such as direct catheter thrombolysis, balloon-assisted thrombolysis, and mechanical thrombectomy may be more efficient and should be considered in cases in which there is involvement of the deep venous system, declining neurological status, or less invasive treatment options have failed. In this work, we describe a novel technique of ECLIPSE 2L balloon (Balt, Irvine, CA) assisted mechanical thrombectomy for straight sinus thrombosis and a review of dural sinus thrombosis management.

Cerebral venous sinus thrombosis detected using diffusion-weighted magnetic resonance imaging during maintenance temozolomide chemotherapy in a patient with glioblastoma: illustrative case.

Cerebral venous sinus thrombosis (CVST) sometimes occurs in the background of hypercoagulopathic disorders, including malignancy, chemotherapy, etc. Glioblastoma (GBM) is a malignancy found in the central nervous system, and reports on cases of GBM complicated by CVST are sparse. The authors herein report a case of GBM complicated by CVST during maintenance temozolomide (TMZ) chemotherapy and describe the utility of diffusion-weighted magnetic resonance imaging (MRI) for the detection of CVST. A 65-year-old male was treated for left temporal GBM. After surgical removal of the lesion, the patient was treated with chemoradiation therapy, which included 60 Gy local radiation with concomitant TMZ chemotherapy. He was subsequently received TMZ maintenance therapy. Routine MRI performed 7 months after surgery revealed no evidence of tumor recurrence. However, diffusion-weighted imaging (DWI) revealed a high-intensity signal at the posterior portion of the superior sagittal sinus, indicating the presence of a thrombus. In addition to the preexisting symptoms, the patient experienced some disorientation. Angiography revealed an obstruction in the superior sagittal sinus, right transverse sinus, right sigmoid sinus, and straight sinus. His symptoms improved with endovascular and anticoagulant therapy. Performing DWI during routine follow-up can help in the early diagnosis of CVST in patients with malignant gliomas.

Cerebral Sinus Hemodynamics in Adults Revealed by 4D Flow MRI.

The hemodynamics of the cerebral sinuses play a vital role in understanding blood flow-related diseases, yet the hemodynamics of the cerebral sinuses in normal adults remains an unresolved issue. To evaluate hemodynamics in the cerebral sinus of adults using 4-dimensional flow MRI (4D Flow MRI). Cross-sectional. Ninety-nine healthy volunteers (mean age, 42.88 ± 13.16 years old; females/males, 55/44). 3 T/4D Flow MRI. The blood flow velocity, average blood flow rate (Q), and vortexes at the superior sagittal sinus (SSS), straight sinus (STS), transverse sinus, sigmoid sinus, and jugular bulb of each volunteer were evaluated by two independent neuroradiologists. The relationship between the total cerebral Q and sex and age was also assessed. Twelve volunteers underwent two scans within a month. The intraclass correlation coefficient (ICC) evaluated the inter-observer agreement. Blood flow parameters among volunteers were compared by the independent-sample t-test or Mann-Whitney U test. The multiple linear regression equation was used to evaluate the relationship between total cerebral Q and age and sex. P < 0.05 indicated statistical significance. The test-retest and interobserver reliability of average velocity and Q were moderate to high (ICC: 0.54-0.99). Cerebral sinus velocity varied by segment and cardiac cycle. The SSS's velocity and Q increased downstream and Q near torcular herophili was 3.5 times that through the STS. The total cerebral Q decreased by 0.06 mL/s per year (β = -0.06 ± 0.013) and was sex-independent within the group. Vortexes were found in 12.12%, 8.9%, and 59.8% of torcular herophili, transverse-sigmoid junction, and jugular bulb, respectively, and were related to higher upstream flow. Cerebral sinuses could be measured visually and quantitatively in vivo by 4D Flow MRI, providing a basis for future research on pulsating tinnitus, multiple sclerosis, and other related diseases. 2 TECHNICAL EFFICACY: Stage 1.

Computational Fluid Dynamic Simulation of the Cerebral Venous System in Multiple Sclerosis and Control Patients: Are Hemodynamic Variances Evident in Multiple Sclerosis?

An investigation was performed to determine the relevant hemodynamic parameters which could help assess vascular pathology in human diseases. Using these parameters, this study aims to assess if there are any hemodynamic differences in the cerebral veins of multiple sclerosis (MS) patients and controls which could impact the etiology of MS. 40 MS participants and 20 controls were recruited for this study. Magnetic resonance imaging (MRI) was performed to enable 3D geometries of the anatomy and the blood flow rates at the boundaries to be computed. Computational fluid dynamics (CFD) models were created for each participant and simulated using patient-specific boundary conditions. The pressure drop and vascular resistance did not significantly differ between the groups. The internal jugular vein (IJV) cross-sectional area was larger in the MS group (Right IJV: p = 0.04, Left IJV: p = 0.02) and the straight sinus (ST) flow rate was higher in MS across all ages (p = 0.005) compared to controls. Vascular resistance was shown to indicate regions in the cerebral veins which could correspond to increased venous pressure. Conclusion & Significance: This study shows that the pressure and vascular resistance of the cerebral veins are unlikely to be directly related to the etiology of MS. The finding of higher ST flow could correspond to increased inflammation in the deep venous system. Resistance as a measure of vascular pathology shows promise and could be useful to holistically investigate blood flow hemodynamics in a variety of other diseases of the circulatory system.

Observation of intracranial artery and venous sinus hemodynamics using compressed sensing-accelerated 4D flow MRI: performance at different acceleration factors.

To investigate the feasibility and performance of 4D flow MRI accelerated by compressed sensing (CS) for the hemodynamic quantification of intracranial artery and venous sinus. Forty healthy volunteers were prospectively recruited, and 20 volunteers underwent 4D flow MRI of cerebral artery, and the remaining volunteers underwent 4D flow MRI of venous sinus. A series of 4D flow MRI was acquired with different acceleration factors (AFs), including sensitivity encoding (SENSE, AF = 4) and CS (AF = CS4, CS6, CS8, and CS10) at a 3.0 T MRI scanner. The hemodynamic parameters, including flow rate, mean velocity, peak velocity, max axial wall shear stress (WSS), average axial WSS, max circumferential WSS, average circumferential WSS, and 3D WSS, were calculated at the internal carotid artery (ICA), transverse sinus (TS), straight sinus (SS), and superior sagittal sinus (SSS). Compared to the SENSE4 scan, for the left ICA C2, mean velocity measured by CS8 and CS10 groups, and 3D WSS measured by CS6, CS8, and CS10 groups were underestimated; for the right ICA C2, mean velocity measured by CS10 group, and 3D WSS measured by CS8 and CS10 groups were underestimated; for the right ICA C4, mean velocity measured by CS10 group, and 3D WSS measured by CS8 and CS10 groups were underestimated; and for the right ICA C7, mean velocity and 3D WSS measured by CS8 and CS10 groups, and average axial WSS measured by CS8 group were also underestimated (all p < 0.05). For the left TS, max axial WSS and 3D WSS measured by CS10 group were significantly underestimated (p = 0.032 and 0.003). Similarly, for SS, mean velocity, peak velocity, average axial WSS measured by the CS8 and CS10 groups, max axial WSS measured by CS6, CS8, and CS10 groups, and 3D WSS measured by CS10 group were significantly underestimated compared to the SENSE4 scan (p = 0.000-0.021). The hemodynamic parameters measured by CS4 group had only minimal bias and great limits of agreement compared to conventional 4D flow (SENSE4) in the ICA and every venous sinus (the max/min upper limit to low limit of the 95% limits of agreement = 11.4/0.03 to 0.004/-5.7, 14.4/0.05 to -0.03/-9.0, 12.6/0.04 to -0.03/-9.4, 16.8/0.04 to 0.6/-14.1; the max/min bias = 5.0/-1.2, 3.5/-1.4, 4.5/-1.1, 6.6/-4.0 for CS4, CS6, CS8, and CS10, respectively). CS4 strikes a good balance in 4D flow between flow quantifications and scan time, which could be recommended for routine clinical use.

Purely Endoscopic Supracerebellar Infratentorial Approach to the Pineal Region in Pediatric Population.

Pineal lesions represent less than 1% of all brain tumors (Villani et al., Clin Neurol Neurosurg 109:1-6, 2007). The abysmal location and critical neurovascular structures remain a surgical challenge, despite the advent of microneurosurgery. The classical wide surgical suboccipital craniotomy with the supracerebellar infratentorial approach, described by Sir Victor Horsley (Victor, Proc R Soc Med 3:77-78, 1910), is infamous for its considerable surgical morbidity and mortality. This was later upgraded microneurosurgically by Stein to improve surgical outcomes (Stein, J Neurosurg 35:197-202, 1971).Ruge et al. reported the first purely endoscopic fenestration of quadrigeminal arachnoid cysts via this corridor (Ruge et al., Neurosurgery 38:830-7, 1996). A cadaver-based anatomical study by Cardia et al. demonstrated the viability for endoscope-assisted techniques (Cardia et al., J Neurosurg 2006;104(6 Suppl):409-14). However, the first purely endoscopic supracerebellar infratentorial (eSCIT) approach to a pineal cyst was performed in 2008 by Gore et al. (Gore PA et al., Neurosurgery 62:108-9, 2008).Unlike transventricular endoscopy, eSCIT approach poses no mechanical risk to the fornices and can be utilized irrespective of ventricular size. More vascular control and resultant reduction in uncontrolled hemorrhage improve the feasibility of attaining complete resection, especially around corners (Zaidi et al,, World Neurosurg 84, 2015). Gravity-dependent positioning and cerebrospinal fluid (CSF) diversion aid cerebellar relaxation, creating the ideal anatomical pathway. Also, angle of the straight sinus, tentorium, and tectal adherence can often influence the choice of approach; thus direct endoscopic visualization not only counteracts access to the engorged Galenic complex but also encourages sharp dissection of the arachnoid (Cardia et al., J Neurosurg 104:409-14, 2006). These tactics help provide excellent illumination with magnification, making it less fatiguing for the surgeon (Broggi et al., Neurosurgery 67:159-65, 2010).The purely endoscopic approach thwarts the dreaded risk of air embolisms, via simple copious irrigation from a small burr hole (Shahinian and Ra, J Neurol Surg B Skull Base 74:114-7, 2013). The tiny opening and closure are rapid to create, and the smaller wound decreases postoperative pain and morbidity. Recent literature supports its numerous advantages and favorable outcomes, making it a tough contender to traditional open methods.

Circular Configuration of Torcular Herophili Presenting as Childhood Headache: 2D Computational Fluid Dynamic Analysis with a Proposed Mechanism.

This case report presents a rare anatomical variant of the torcular Herophili, characterized by a circular configuration and the absence of the left transverse sinus. A 12-year-old child presented with intermittent holocranial headaches, and imaging revealed the circular torcular Herophili along with mild ventricular enlargement. The straight sinus drained into the left side of the circular torcular Herophili. Following lumbar puncture and cerebrospinal fluid (CSF) drainage, the child experienced symptom improvement. During a 6-month follow-up, the patient remained asymptomatic, without further headaches or academic disruptions. Similar to a previously reported case, the circular torcular Herophili with unilateral absent transverse sinus may be associated with impaired CSF absorption due to altered blood flow through abnormal venous anatomy. We performed two-dimensional computational fluid dynamic analysis of simulated flow through a synthetic model and showed that this circular configuration is associated with venous stasis. The venous stasis in the sinus may impair CSF absorption through the arachnoid granulations causing hydrocephalus and explaining the headache. Close monitoring and follow-up are recommended for patients with this variant. Further investigation is needed to better understand the clinical implications and underlying mechanisms of such torcular Herophili variations.