Parasagittal meningiomas: Our surgical experience and the reconstruction technique of the superior sagittal sinus

Route patterns of the collateral venous pathway in patients with tumors invading the superior sagittal sinus: an angiographic study and clinical applications

Chronic occlusion of the superior sagittal sinus (SSS) by tumors in the midsagittal region causes the collateral venous pathway (CVP). Understanding common patterns of CVP is helpful in reducing surgical complications. This study aimed to investigate the CVP found in patients with SSS-invading tumors, and to provide information on the prevention of operative venous complications. From January 2015 to December 2022, this retrospective study collected patients with tumors that invaded the SSS and underwent digital subtraction angiography of intracranial vessels. Data collected included sex, age, tumor pathology, tumor location along the SSS, tumor side, degree of obstruction of the SSS, types and route patterns of the CVP, and the distance between the tumor and the diploic vein (DV). Twenty patients (6 males, 14 females) were recruited. The prevalence of CVP types was 90% for DV, 35% for end-to-end anastomosis of superficial cortical vein, 15% for meningeal vein, and 20% for other types of CVP. The pteriofrontoparietal and occipitoparietal diploic routes were found on the cerebral hemisphere contralateral to the tumor significantly more than in the cerebral hemisphere ipsilateral to the tumor. Of all patients with presence of collateral DV, 61% had a very close (less than 1 cm) distance between the nearest DV and tumor attachment in the SSS. DV in the cerebral hemisphere contralateral to the tumor was the most common type of CVP found in patients with tumor-induced SSS obstruction. Most of the collateral DV was located very close to the SSS tumor attachment. Neurosurgeons should realize these findings when planning a craniotomy.

Microsurgical Management of Complex Meningiomas Involving Dural Venous Sinuses: Operative Techniques, Case Illustrations and Long-Term Outcomes in a Series of 70 Cases

BACKGROUND

Meningiomas involving the dural venous sinuses present unique therapeutic challenges. While gross total resection remains the mainstay of treatment for meningiomas, involvement of critical vascular structures may limit extent of resection and increase the risk of recurrence. Optimal management of meningiomas with venous sinus involvement has been discussed in the literature, with some advocating for subtotal resection with postoperative surveillance and radiation, if necessary, while others recommend total resection with reconstruction of resection of the involved sinus.

METHODS

We performed a review of our series of 70 patients at a single institution who underwent resection of a meningioma involving the dural venous sinuses with reconstruction as needed, evaluating demographics, preoperative assessment of venous anatomy, surgical technique, and outcomes.

RESULTS

In our series, we found successful maximal safe resection was achievable in patients with dural venous sinus involvement. We identified no venous infarctions and a low rate of recurrence.

CONCLUSIONS

Maximal safe resection, including resection and reconstruction of involved sinuses, may be a safe and effective treatment for many patients. Careful preoperative assessment of venous anatomy and planning extent of resection and reconstruction are essential for safe and successful surgery in these patients.

MRI- and DWI-Based Radiomics Features for Preoperatively Predicting Meningioma Sinus Invasion

The aim of this study was to use multimodal imaging (contrast-enhanced T1-weighted (T1C), T2-weighted (T2), and diffusion-weighted imaging (DWI)) to develop a radiomics model for preoperatively predicting venous sinus invasion in meningiomas. This prediction would assist in selecting the appropriate surgical approach and forecasting the prognosis of meningiomas. A retrospective analysis was conducted on 331 participants who had been pathologically diagnosed with meningiomas. For each participant, 3948 radiomics features were acquired from the T1C, T2, and DWI images. Minimum redundancy maximum correlation, rank sum test, and multi-factor recursive elimination were used to extract the most significant features of different models. Then, multivariate logistic regression was used to build classification models to predict meningioma venous sinus invasion. The diagnostic capabilities were assessed using receiver operating characteristic (ROC) analysis. In addition, a nomogram was constructed by incorporating clinical and radiological characteristics and a radiomics signature. To assess the clinical usefulness of the nomogram, a decision curve analysis (DCA) was performed. Tumor shape, boundary, and enhancement features were independent predictors of meningioma venous sinus invasion (p = 0.013, p = 0.013, p = 0.005, respectively). Eleven (T2:1, T1C:4, DWI:6) of the 3948 radiomics features were screened for strong association with meningioma sinus invasion. The areas under the ROC curves for the training and external test sets were 0.946 and 0.874, respectively. The clinicoradiomic model showed excellent predictive performance for invasive meningioma, which may help to guide surgical approaches and predict prognosis.

Progression/Recurrence of Meningioma: An Imaging Review Based on Magnetic Resonance Imaging

Meningiomas are the most common primary central nervous system tumors. The preferred treatment is maximum safe resection, and the heterogeneity of meningiomas results in a variable prognosis. Progression/recurrence (P/R) can occur at any grade of meningioma and is a common adverse outcome after surgical treatment and a major cause of postoperative rehospitalization, secondary surgery, and mortality. Early prediction of P/R plays an important role in postoperative management, further adjuvant therapy, and follow-up of patients. Therefore, it is essential to thoroughly analyze the heterogeneity of meningiomas and predict postoperative P/R with the aid of noninvasive preoperative imaging. In recent years, the development of advanced magnetic resonance imaging technology and machine learning has provided new insights into noninvasive preoperative prediction of meningioma P/R, which helps to achieve accurate prediction of meningioma P/R. This narrative review summarizes the current research on conventional magnetic resonance imaging, functional magnetic resonance imaging, and machine learning in predicting meningioma P/R. We further explore the significance of tumor microenvironment in meningioma P/R, linking imaging features with tumor microenvironment to comprehensively reveal tumor heterogeneity and provide new ideas for future research.

Predictors of recurrence after surgical resection of parafalcine and parasagittal meningiomas

PURPOSE

Owing to their vicinity near the superior sagittal sinus, parasagittal and parafalcine meningiomas are challenging tumors to surgically resect. In this study, we investigate key factors that portend increased risk of recurrence after surgery.

METHODS

This is a retrospective study of patients who underwent resection of parasagittal and parafalcine meningiomas at our institution between 2012 and 2018. Relevant clinical, radiographic, and histopathological variables were selected for analysis as predictors of tumor recurrence.

RESULTS

A total of 110 consecutive subjects (mean age: 59.4 ± 15.2 years, 67.3% female) with 74 parasagittal and 36 parafalcine meningiomas (92 WHO grade 1, 18 WHO grade 2/3), are included in the study. A total of 37 patients (33.6%) exhibited recurrence with median follow-up of 42 months (IQR: 10-71). In the overall cohort, parasagittal meningiomas exhibited shorter progression-free survival compared to parafalcine meningiomas (Kaplan-Meier log-rank p = 0.045). On univariate analysis, predictors of recurrence include WHO grade 2/3 vs. grade 1 tumors (p < 0.001), higher Ki-67 indices (p < 0.001), partial (p = 0.04) or complete sinus invasion (p < 0.001), and subtotal resection (p < 0.001). Multivariable Cox regression analysis revealed high-grade meningiomas (HR: 3.62, 95% CI: 1.60-8.22; p = 0.002), complete sinus invasion (HR: 3.00, 95% CI: 1.16-7.79; p = 0.024), and subtotal resection (HR: 3.10, 95% CI: 1.38-6.96; p = 0.006) as independent factors that portend shorter time to recurrence.

CONCLUSION

This study identifies several pertinent factors that confer increased risk of recurrence after resection of parasagittal and parafalcine meningiomas, which can be used to devise appropriate surgical strategy to achieve improved patient outcomes.

Update on meningioma: Clinical-radiological and radio-pathological correlation

Meningiomas are tumors that originate in the arachnoid villi and are the most common non-glial neoplasm in the central nervous system. The clinical manifestations associated with meningioma depend, fundamentally, on its location. The location in the cerebral convexity is the most frequent, especially in the frontal lobes, manifesting with headache, motor disturbances, seizures and even neurocognitive disorders. There are 15 histologic subtypes of meningioma and three histologic grades. Within these, grades two and three have a worse prognosis and a higher rate of recurrence, as well as a radiological behavior that is generally more aggressive. Although there are some imaging features that can suggest a specific subtype, the definitive diagnosis will always require histological/molecular confirmation.

Analysis of the common complications and recurrence-related factors of superior parasagittal sinus meningioma

Objectives

Parasagittal meningioma resection is prone to postoperative complications and tumor recurrence because the tumor invades the superior sagittal sinus. This study aimed to clarify the incidence of perioperative complications and the recurrence of superior sagittal paranasal meningiomas and explored potential predictors in this context.

Methods

The study retrospectively reviewed the clinical, imaging, and follow-up data of parasagittal meningiomas among patients who underwent microsurgical resection in the authors' institution from January 2008 to December 2017. Univariate and multivariate logistic regression analyses were conducted to explore independent predictors of perioperative complications and tumor recurrence.

Results

A total of 212 parasagittal meningioma patients were included in this study. The incidence of perioperative complications was 23.6% (50/212), and perioperative death occurred in 6 (2.8%) patients. In univariate and multivariate logistic regression analyses of perioperative complications, peritumoral edema ≥1 cm (odds ratio [OR] 2.163, 95% confidence interval [CI] 1.057-4.428, P = 0.035) and the Sindou invasion Class V-VI(OR0.018, 95% CI 1.248-11.064, P = 0.018) were independent predictors. After an average of 83 (39-154) months of clinical follow up among the living 206 patients, 22 (10.7%) patients showed tumor recurrence. In univariate and multivariate logistic regression analyses of tumor recurrence, the Sindou invasion Class III-IV (OR 5.539, 95%CI 1.469-20.884, P = 0.011) and the Sindou invasion Class V-VI (OR 9.144, 95%CI 2.215-37.757, P = 0.002) were independent predictors.

Conclusions

Peritumoral edema ≥1 cm and the Sindou invasion Class V-VI were the independent predictors of perioperative complications, and the Sindou invasion Class III-IV and the Sindou invasion Class V-VI were the independent predictors of tumor recurrence. The part of the parasagittal meningioma involving the sinus wall should be actively removed to the largest degree possible to reduce the recurrence rate.

Preoperative surgical risk assessment of meningiomas: a narrative review based on MRI radiomics

Meningiomas are one of the most common intracranial primary central nervous system tumors. Regardless of the pathological grading and histological subtypes, maximum safe resection is the recommended treatment option for meningiomas. However, considering tumor heterogeneity, surgical treatment options and prognosis often vary greatly among meningiomas. Therefore, an accurate preoperative surgical risk assessment of meningiomas is of great clinical importance as it helps develop surgical treatment strategies and improve patient prognosis. In recent years, an increasing number of studies have proved that magnetic resonance imaging (MRI) radiomics has wide application values in the diagnostic, identification, and prognostic evaluations of brain tumors. The vital importance of MRI radiomics in the surgical risk assessment of meningiomas must be apprehended and emphasized in clinical practice. This narrative review summarizes the current research status of MRI radiomics in the preoperative surgical risk assessment of meningiomas, focusing on the applications of MRI radiomics in preoperative pathological grading, assessment of surrounding tissue invasion, and evaluation of tumor consistency. We further analyze the prospects of MRI radiomics in the preoperative assessment of meningiomas angiogenesis and adhesion with surrounding tissues, while pointing out the current challenges of MRI radiomics research.

Surgical outcomes and prognostic factors of parasagittal meningioma: a single-center experience 165 consecutive cases

PURPOSE

This study aimed to estimate the prognostic factors, long-term outcomes, and surgical strategies for parasagittal meningioma (PSM) and provide a better understanding of surgical experience.

MATERIALS AND METHODS

Patients (n = 1438) who underwent surgery for meningioma between January 2012 and January 2013 were enrolled in a database. We then identified 165 patients with PSM based on this database.

RESULTS

Of the 165 patients with identified PSMs, 103 were female and 62 were male, with a mean age of 49 years. Univariate analysis revealed that male sex (p = .002), non-World Health Organization (WHO) grade I meningioma (p < .001), treatment history (p = .006), surgical time more than 232 minutes (p = .006), and intraoperative bleeding > 300mL³ (p = .019) were associated with decreased progression-free survival (PFS). Multivariate analysis revealed that sex (hazards ratio [HR] = 3.836, 95% confidence interval [CI] = 1.364-10.794; p = .011], tumour grade (HR = 8.479, 95% CI = 3.234-22.230; p < .001), and surgical time (HR = 3.710, 95% CI = 1.057-13.023; p = .041) were independent factors for PFS. Patients with Simpson grade I-II (p = .015), no-treatment history (p = .006), tumour size < 3cm (p = .005), surgical time < 232 minutes (p = .019), intraoperative bleeding < 300mL³ (p < .001), or WHO grade I meningioma (p = .002) had better follow-up conditions.

CONCLUSION

Surgery was an effective treatment for PSM, and at the time of final follow-up, patients who received aggressive resection had a substantially higher Karnofsky performance scale score.

What is the ideal grade of resection for parasagittal meningiomas with the invasion of superior sagittal sinus? Simpson I or Simpson II resection? A retrospective observational study

Background:

Parasagittal meningioma (PSM) is a tumor located in the parasagittal angle which extends to and/ or invades the superior sagittal sinus (SSS). Surgical resection of the PSM, the standard treatment in such cases, poses a challenge for neurosurgery, particularly where there is an invasion of the SSS. This is due to the risk of complications through injury to the adjacent vascular structures. The objective of the study was to perform a comparative evaluation of the surgical techniques for total resection of the PSM (Simpson Grade [SG] I and SG II), which present the highest rates of success in terms of the following variables: mortality, recurrence, and postoperative complications.

Methods:

Fifty-six patients undergoing resection surgery for PSM with the invasion of the SSS were enrolled. The patients were divided into two groups: Group A, comprising 26 cases of patients subjected to SG I PSM resection surgery and Group B, with 31 cases of patients subjected to SG II PSM resection surgery, with preservation of the SSS.

Results:

The results showed that Group B had lower rates of postoperative deficit (P = 0.026), zero mortality, and reduced recurrence. The use of complementary radiotherapy for atypical meningiomas (WHO II) in Group B was satisfactory in controlling the disease.

Conclusion:

The Simpson II, with preservation of the SSS, was better as it diminishes the vascular risks of surgery, reduces the frequency of severe postoperative deficit, and reduces mortality.

Recurrence of surgically treated parasagittal meningiomas: a meta-analysis of risk factors

BACKGROUND

As the predictive role of many risk factors for parasagittal meningioma (PM) recurrence remains unclear, the objective of the meta-analysis was to make a comprehensive assessment of the predictive value of selected risk factors in these lesions.

METHODS

Studies including data on selected risk factors, such as histology, tumor and sinus resection, sinus invasion, tumor localization, and immediate postoperative radiotherapy for PMs recurrence, were searched in the NCBI/NLM PubMed/MEDLINE, EBM Reviews/Cochrane Central, ProQuest, and Scopus databases, and analyzed using random effects modeling.

RESULTS

Thirteen observational studies involving 1243 patients met the criteria for inclusion in the meta-analysis. WHO grading of meningiomas was identified as the most powerful risk factor for recurrence. WHO grade II meningiomas (OR 11.61; 95% CI 4.43-30.43; P < .01; I² = 31%) or composite group of WHO grades II and III (OR 14.84; 95% CI 5.10-43.19; P < .01; I² = 48%) had a significantly higher risk of recurrence than benign lesions. Moreover, an advanced sinus involvement (types IV-VI according to the Sindou classification) (OR 3.49; 95% CI 1.30-9.33; P = .01; I² = 0%) and partial tumor resection (Simpson grades III-V) (OR 2.73; 95% CI 1.41-5.30; P = .03; I² = 52%) were associated with a significantly higher risk of recurrence than their counterparts.

CONCLUSION

Among the selected risk factors, high-grade WHO lesions, advanced sinus invasion, and partial tumor resection were associated with a higher risk of PM recurrence, with WHO grading system being the most powerful risk factor.

Predictors of Nonroutine Discharge Disposition Among Patients with Parasagittal/Parafalcine Meningioma

OBJECTIVE

Discharge disposition is an important outcome for neurosurgeons to consider in the context of high-quality, value-based care. There has been limited research into how the unique anatomic considerations associated with parasagittal/parafalcine meningioma resection may influence discharge disposition. We investigated the effects of various predictors on discharge disposition within a cohort of patients with parasagittal/parafalcine meningioma.

METHODS

A total of 154 patients treated at a single institution were analyzed (2016-2019). Bivariate analysis was conducted using the Mann-Whitney U and Fisher exact tests. Multivariate analysis was conducted using logistic regression. An optimism-corrected C-statistic was calculated using 2000 bootstrap samples to assess logistic regression model performance.

RESULTS

Our cohort was mostly female (67.5%) and white (72.7%), with a mean age of 57.29 years. Most patients had tumors associated with the middle third of the superior sagittal sinus (SSS) (60.4%) and had tumors that were not fully occluding the SSS (74.0%). In multivariate analysis, independent predictors of nonroutine discharge disposition included 5-factor Modified Frailty Index score (odds ratio [OR], 2.06; P = 0.0088), Simpson grade IV resection (OR, 4.22; P = 0.0062), and occurrence of any postoperative complication (OR, 2.89; P = 0.031). The optimism-corrected C-statistic of our model was 0.757.

CONCLUSIONS

In our single-institution experience, neither extent of SSS invasion nor location along the SSS predicted nonroutine discharge, suggesting that tumor invasion and posterior location along the SSS are not necessarily contraindications to surgery. Our results also highlight the importance of frailty and tumor size in stratifying patients at risk of nonroutine discharge disposition.

Long-term outcomes of multimodality management for parasagittal meningiomas

PURPOSE

The aim of this study was to systematically analyze the clinical characteristics of a large cohort of parasagittal meningioma (PM) and to evaluate the patients' outcomes and best treatment strategies based on tumor features.

METHODS

To minimize selection bias we performed a single-institutional review of PM with restricted criteria. One hundred and ninety-two consecutive patients who met criteria for inclusion were reviewed from 2003 to 2011 in our general hospital.

RESULTS

A total of 131 cases (68.2%) were with WHO grade I, while grade II and grade III PMs constituted 40 (20.8%) and 21 cases (10.9%). Higher histological grade was associated with loss of trimethylation of H3K27 (P = 0.000). For WHO grade I PMs, GTR was significantly associated with a better PFS (P = 0.023); however, adjuvant radiotherapy did not benefit patients with STR (P = 0.215). For de novo high-grade (WHO grade II and III) PMs (n = 37), adjuvant radiotherapy was associated with a significantly longer OS (P = 0.013), while no difference was observed between GTR and STR (P = 0.654). In recurrent high-grade PM patients (n = 24), GTR combined with adjuvant radiotherapy increased PFS (P = 0.005).

CONCLUSIONS

This study demonstrated that PMs were a heterogeneous group of tumors with a high proportion of high-grade tumors that often displayed aggressive clinical behaviors. Low-grade PM benefited from radical resection, whereas high-grade de novo PM did not. Adjuvant radiotherapy significantly prolonged OS for high-grade primary PM, but did not impact survival of patients with subtotally resected low-grade tumors. Long-term outcome of high-grade recurrent PMs was dismal. We thus show that extent of tumor resection, tumor grade and tumor recurrent status inform therapeutic decisions for PMs.

Resection of Meningiomas Involving Major Dural Venous Sinuses: Classification, Technique, and Long-Term Results

OBJECTIVE

Management of meningiomas with major dural venous sinus involvement is challenging. We present our case series and perspective on reconstruction of the sinuses.

METHODS

Fifty-five patients underwent operations between 2005 and 2016 and the retrospective data were collected and analyzed.

RESULTS

The cohort was younger with a mean of 51.3 years (range, 19-72 years) predominantly involving the superior sagittal sinus (44 patients). Sinus involvement was classified into group 1 (<50% of sinus, n = 28), group 2 (50%-99%, n = 8), and group 3 (total occlusion, n = 19). Venous collateralization was present in 100% of group 2 and 3 and in 36% of group 1 occlusions. Sinus pericranii was seen in 22 patients. Gross total resection was achieved in 87.2%, and sinus reconstruction followed in 38 patients (24 by direct suture and 14 by a patch graft). Pathology showed 36 (65%) World Health Organization grade I, 18 (33%) grade II, and 1 (2%) grade III tumors. During the mean follow-up of 60 months (range, 1-132 months), sinus was patent (74%) or narrowed but patent (24%) in 98%; 2 recurrences (3.6%) were observed (at 24 and 120 months). The mean preoperative/postoperative Karnofsky Performance Status and Kaplan-Meier cumulative overall/recurrence-free survival were 84.2%/88.1% and 90.9%/80.1%, respectively.

CONCLUSIONS

These meningiomas present in a younger population, are more likely to be World Health Organization grade II or III, necessitating a more aggressive tumor resection strategy. Aggressive resection coupled with sinus reconstruction results in good long-term surgical outcome and low recurrence rates.

High-Frequency Irreversible Electroporation for Intracranial Meningioma: A Feasibility Study in a Spontaneous Canine Tumor Model

High-frequency irreversible electroporation is a nonthermal method of tissue ablation that uses bursts of 0.5- to 2.0-microsecond bipolar electric pulses to permeabilize cell membranes and induce cell death. High-frequency irreversible electroporation has potential advantages for use in neurosurgery, including the ability to deliver pulses without inducing muscle contraction, inherent selectivity against malignant cells, and the capability of simultaneously opening the blood–brain barrier surrounding regions of ablation. Our objective was to determine whether high-frequency irreversible electroporation pulses capable of tumor ablation could be delivered to dogs with intracranial meningiomas. Three dogs with intracranial meningiomas were treated. Patient-specific treatment plans were generated using magnetic resonance imaging-based tissue segmentation, volumetric meshing, and finite element modeling. Following tumor biopsy, high-frequency irreversible electroporation pulses were stereotactically delivered in situ followed by tumor resection and morphologic and volumetric assessments of ablations. Clinical evaluations of treatment included pre- and posttreatment clinical, laboratory, and magnetic resonance imaging examinations and adverse event monitoring for 2 weeks posttreatment. High-frequency irreversible electroporation pulses were administered successfully in all patients. No adverse events directly attributable to high-frequency irreversible electroporation were observed. Individual ablations resulted in volumes of tumor necrosis ranging from 0.25 to 1.29 cm³. In one dog, nonuniform ablations were observed, with viable tumor cells remaining around foci of intratumoral mineralization. In conclusion, high-frequency irreversible electroporation pulses can be delivered to brain tumors, including areas adjacent to critical vasculature, and are capable of producing clinically relevant volumes of tumor ablation. Mineralization may complicate achievement of complete tumor ablation.

Optimal surgical strategy for meningiomas involving the superior sagittal sinus: a systematic review

Involvement of the superior sagittal sinus (SSS) by meningiomas poses specific challenges, without an agreement about the degree of surgical aggressiveness when dealing with these lesions. In this systematic review and meta-analysis, we compare outcomes and complication rates, after different surgical strategies. Studies focused on meningiomas involving the SSS were collected from numerous online databases. Surgical outcome and complication data were abstracted. Comparisons were made considering complication and recurrence rates between an "aggressive" and a "non-aggressive" surgical attitude. A total of 26 studies, encompassing 1614 patients, were identified. Most of the tumors (53%) arose from the middle third of SSS and 75% of patients had a patent sinus at the time of surgery. A favorable outcome was achieved in 73% of patients treated with an "aggressive" surgical attitude compared to 78% of patients treated with a "non-aggressive" surgical attitude. Complication rates were similar between "aggressive" and "non-aggressive" attitudes, except for a higher rate of venous infarct (4% versus 2%, respectively) and worsening of preexisting motor deficits (34% versus 13%, respectively) in aggressively treated patients. Recurrence rates were not substantially different in the two groups after accounting for length of follow-up. Patients with incomplete resection (Simpson grades II-V) or with high histological grade (WHO grade III) had significantly higher recurrence rates. A complete resection achieves higher rates of tumor control, however, without nullifying the risk of recurrence. Moreover, "aggressive" tumor removal is associated with higher rates of venous complications and worsening of preexisting motor deficits.

Feasibility of High-Resolution 3-Dimensional Sampling Perfection with Application-Optimized Contrast Using Different Flip Angle Evolution Imaging for the Preoperative Detection of Parasinus Meningioma: A Pilot Study Compared with Contrast-Enhanced Magnetic Resonance Venography

OBJECTIVES

To prospectively evaluate the diagnostic value of 3.0 Tesla magnetic resonance 3-dimensional sampling perfection with application-optimized contrast using different flip angle evolution (3D-SPACE) in the detection of sinus wall invasion and sinus patency in parasinus meningiomas.

METHODS

In this study, 28 patients with suspected meningiomas adjacent to the venous sinus underwent conventional magnetic resonance imaging, contrast-enhanced magnetic resonance venography, and 3D-SPACE scans. We collected patient charts and surgical reports for demographic details, histologic analysis, and neurologic performance preoperatively and postoperatively. Images obtained by each technique were assessed independently by 2 neurosurgeons for characteristics of sinus infiltration, wall invasion, lumen patency, and collateral veins.

RESULTS

The blood flow signal inside the lumen and collateral veins were depressed and presented as black, contrasting well with the sinus wall on 3D-SPACE imaging. When the curved-planar reconstruction images were combined, it was intuitive and accurate to detect the extent of sinus wall invasion by meningioma and also to detect lumen patency. An intratumoral "false lumen" was shown to maintain the blood flow inside the sinus at a totally invaded lesion. Moreover, collateral veins enveloped in a meningioma with their confluence points of the venous sinus were easily observed on 3D-SPACE images.

CONCLUSION

With an integrative presentation of parasinus meningioma, wall invasion, lumen patency, and collateral veins, high-resolution 3D-SPACE imaging provides a reliable technique to accurately assess venous sinus invasion preoperatively.