Purpose To compare arterial spin labeling (ASL) data between low- and high-grade brain tumors in children to establish a cutoff to distinguish low- from high-grade neoplasms and to assess potential ...correlations between cerebral blood flow (CBF) and quantitative histologic microvascular data. Materials and Methods Approval was obtained from the regional review board. ASL data obtained in 129 children between 2011 and 2015 were retrospectively analyzed. CBF and relative CBF in the most perfused area of each neoplasm and contrast enhancement were quantified with a semiquantitative ratio. The correlation between CBF and microvascular density was analyzed in specimens stained with anti-CD34. Results were controlled in two validation cohorts with 1.5- and 3.0-T magnetic resonance (MR) imaging. Results Mean CBF was significantly higher for high-grade than for low-grade hemispheric (116 mL/min/100 g interquartile range {IQR}, 73-131 mL/min/100 g vs 29 mL/min/100 g IQR, 23-35 29 mL/min/100 g, P < .001), thalamic (87 mL/min/100 g IQR, 73-100 mL/min/100 g vs 36 mL/min/100 g IQR, 30-40 mL/min/100 g, P = .016), and posterior fossa (59 mL/min/100 g IQR, 45-91 mL/min/100 g vs 33 mL/min/100 g IQR, 25-40 mL/min/100 g, P < .001) tumors. With a cutoff of 50 mL/min/100 g, sensitivity and specificity were 90% (95% confidence interval CI: 68, 100) and 93% (95% CI: 66, 100), respectively, for hemispheric tumors; 100% (95% CI: 48, 100) and 80% (95% CI: 28, 100), respectively, for thalamic tumors; and 65% (95% CI: 51, 78) and 94% (95% CI: 80, 99), respectively, for posterior fossa tumors. In posterior fossa tumors, additional use of the CBF-to-contrast enhancement ratio yielded sensitivity and specificity of 96% (95% CI: 87, 100) and 97% (95% CI: 84, 100), respectively. Use of a simple algorithm based on these values yielded an accuracy of 93% (95% CI: 87, 97). Validation sets yielded similar results, with grading accuracy of 88% (95% CI: 62, 98) with 1.5-T MR imaging and 77% (95% CI: 46, 95) with 3.0-T MR imaging. CBF was strongly correlated with microvascular density (R = 0.66, P < .001). Conclusion High-grade pediatric brain tumors display higher CBF than do low-grade tumors, and they may be accurately graded by using these values. CBF is correlated with tumor microvascular density.
RSNA, 2016 Online supplemental material is available for this article.
Embolization of the middle meningeal artery (MMA) has emerged as a potential treatment of chronic subdural hematomas (CSDHs).
To evaluate the impact on recurrence rate of postsurgical embolization of ...CSDH in patients with a higher than average risk of recurrence.
A monocentric retrospective study was performed on retrospectively collected data. From March 2018 to December 2019, embolization of the MMA was proposed as an adjunct postoperative treatment after burr-hole surgery in patients operated for a recurrent CSDH or a CSDH with an independent recurrence risk factor, including antiplatelet therapy, full anticoagulation therapy, coagulation disorder, hepatopathy, or chronic alcoholism. Patients who had undergone postoperative embolization were compared with a historic group of patients operated between March 2016 and March 2018, selected based on the same inclusion criteria.
During the study period, 89 patients (with 74 unilateral and 15 bilateral CSDHs) were included and underwent an embolization procedure, leading to 91 out of a total of 104 MMA being embolized (88%). These were compared with 174 patients (138 unilateral and 36 bilateral CSDH) in the historic control group. One major procedure-related adverse event was registered. Four of the 89 patients (4%) required surgery for a CSDH recurrence in the embolization group, significantly less than the 24 of 174 patients (14%) in the control group (OR=0.28, 95% CI 0.07 to 0.86, p=0.02).
Postsurgical embolization of the MMA may reduce the recurrence rate of CSDHs with a risk factor of recurrence.
The literature shows discrepancies in stereotactic brain biopsy complication rates, severities, and outcomes. Little is known about the timeline of postbiopsy complications. This study aimed to ...analyze 1) complications following brain biopsies, using a graded severity scale, and 2) a timeline of complication occurrence. The secondary objectives were to determine factors associated with an increased risk of complications and to assess complication-related management and extra costs.
The authors retrospectively examined 1500 consecutive stereotactic brain biopsies performed in adult patients at their tertiary medical center between April 2009 and April 2019.
Three hundred eighty-one biopsies (25.4%) were followed by a complication, including 88.2% of asymptomatic hemorrhages. Symptomatic complications involved 3.0% of the biopsies, and 0.8% of the biopsies were fatal. The severity grading scale had a 97.6% interobserver reproducibility. Twenty-three (51.1%) of the 45 symptomatic complications occurred within the 1st hour following the biopsy, while 75.6% occurred within the first 6 hours. Age ≥ 65 years, second biopsy procedures, gadolinium-enhanced lesions, glioblastomas, and lymphomas were predictors of biopsy-related complications. Brainstem biopsy-targeted lesions and cerebral toxoplasmosis were predictive of mortality. Asymptomatic hemorrhage was associated with delayed (> 6 hours) symptomatic complications. Symptomatic complications led to extended hospitalization in 86.7% of patients. The average extra cost for management of a patient with postbiopsy symptomatic complication was $35,702.
Symptomatic complications from brain biopsies are infrequent but associated with substantial adverse effects and cost implications for the healthcare system. The use of a severity grading scale, as the authors propose in this article, helps to classify complications according to the therapeutic consequences and the patient's outcome. Because this study indicates that most complications occur within the first few hours following the biopsy, postbiopsy monitoring can be tailored accordingly. The authors therefore recommend systematic monitoring for 2 hours in the recovery unit and a CT scan 2 hours after the end of the biopsy procedure. In addition, they propose a modern algorithm for optimal postoperative management of patients undergoing stereotactic biopsy.
Purpose
Mechanical thrombectomy (MT) failure is associated with very poor prognosis. Permanent intracranial stenting (PIS) may be useful in such refractory occlusions. However, this strategy requires ...an aggressive antithrombotic regimen that may be harmful in extended strokes. The aim of this study was to compare clinical outcomes between patients with refractory acute large vessel occlusions (LVOs) treated by PIS versus patients for whom the procedure was stopped without recanalization.
Methods
We conducted a systematic review by searching for articles in PubMed, the Cochrane Library, and
ClinicalTrials.gov
from January 2015 to September 2019. Two reviewers independently selected studies comparing PIS after failed MT in addition to usual care versus usual care only. A comparative meta-analysis was performed using random-effects models to estimate odds ratios of favorable clinical outcome at 90 days, defined as a modified Rankin scale 0–2, mortality and symptomatic intracranial hemorrhage (SICH).
Results
Four comparative studies were included for a total of 352 patients: 149 in the PIS group versus 203 in the control group. PIS was associated with significantly higher rates of 90-day favorable clinical outcome (odds ratio OR, 2.87 95% confidence interval (95% CI), 1.77–4.66;
p
< 0.001;
I
2
, 0%) and lower mortality (OR, 0.39 0.16–0.93;
p
= 0.03;
I
2
, 43%), whereas SICH rates did not significantly differ (OR, 0.68 0.37–1.27;
p
= 0.23;
I
2
, 0%).
Conclusion
From observational study results, attempting PIS after failed MT seems to improve clinical outcomes without increasing the risk of intracranial bleeding. Randomized trials are needed to confirm these results.
Purpose
Middle meningeal artery (MMA) embolization is emerging as a potential treatment of chronic subdural hematomas (CSDHs). The purpose of this study is to describe MMA angiographic anatomy in ...relation to CSDH embolization.
Methods
This retrospective monocentric study was performed on imaging data of MMA embolization procedures for CSDH treatment performed between March 15, 2018 and April 30, 2020. Imaging data, including digital subtraction angiography (DSA) were reviewed independently by two physicians. Discrepancies were resolved by consensus. The MMA bifurcation pattern was analyzed according to an extended Adachi classification. Relations of the MMA with the ophthalmic artery (OA) were also analyzed.
Results
In this study, 140 MMAs were analyzed. Dominance of the anterior branch (type I) was observed in only 57/140 (41%) MMAs with a moderate interobserver agreement for classifying MMA into type I against all other (κ = 0.53, 95% confidence interval, CI 0.39–0.67). The posterior branch presented a proximal origin (type A), at the point of emergence of the MMA from the foramen spinosum or its immediate vicinity, in 48/135 (36%) MMAs with a very good interobserver agreement for classifying MMAs into type A against all other (κ = 0.82, 95% CI 0.72–0.92). An angiographic relationship with the OA was observed in 26 MMAs (19%).
Conclusion
In the majority of CSDH patients both anterior and posterior branches of the MMA should be targeted to achieve extensive convexity devascularization. Frequent anatomical variations of the MMA with respect to emergence of the posterior branch and MMA orbital branches are expected to impact CSDH embolization strategy.
Objectives
Preoperative embolization of hypervascular spinal metastases (HSM) is efficient to reduce perioperative bleeding. However, intra-arterial digital subtraction angiography (IA-DSA) must ...confirm the hypervascular nature and rule out spinal cord arterial feeders. This study aimed to evaluate the reliability and accuracy of time-resolved contrast-enhanced magnetic resonance angiography (TR-CE-MRA) in assessing HSM prior to embolization.
Methods
All consecutive patients referred for preoperative embolization of an HSM were prospectively included. TR-CE-MRA sequences and selective IA-DSA were performed prior to embolization. Two readers independently reviewed imaging data to grade tumor vascularity (using a 3-grade and a dichotomized “yes vs no” scale) and identify the arterial supply of the spinal cord. Interobserver and intermodality agreements were estimated using kappa statistics.
Results
Thirty patients included between 2016 and 2019 were assessed for 55 levels. Interobserver agreement was moderate (κ = 0.52; 95% CI 0.09–0.81) for TR-CE-MRA. Intermodality agreement between TR-CE-MRA and IA-DSA was good (κ = 0.74; 95% CI 0.37–1.00). TR-CE-MRA had a sensitivity of 97.9%, a specificity of 71.4%, a positive predictive value of 95.9%, a negative predictive value of 83.3%, and an overall accuracy of 94.6%, for differentiating hypervascular from non-hypervascular SM. The arterial supply of the spine was assessable in 2/30 (6.7%) cases with no interobserver agreement (κ < 0).
Conclusions
TR-CE-MRA can reliably differentiate hypervascular from non-hypervascular SM and thereby avoid futile IA-DSAs. However, TR-CE-MRA was not able to evaluate the vascular supply of the spinal cord at the target levels, thus limiting its scope as a pretherapeutic assessment tool.
Key Points
• TR-CE-MRA aids in distinguishing hypervascular from non-hypervascular spinal metastases.
• TR-CE-MRA could avoid one-quarter of patients referred for HSM embolization to undergo futile conventional angiography.
• TR-CE-MRA’s spatial resolution is insufficient to replace IA-DSA in the pretherapeutic assessment of the spinal cord vascular anatomy.
Here is reported a case of dural arteriovenous fistula (DAVF) formation following middle meningeal artery (MMA) embolization. A 64-year-old male patient was operated for a bilateral CSDH by burr-hole ...craniostomy. Prophylactic post-operative MMA embolization was performed with 300–500-μm calibrated microparticles. The patient was admitted 3 months later for a left CSDH recurrence. Digital subtraction angiography demonstrated formation of a superior sagittal sinus DAVF fed by both superficial temporal arteries. This case highlights the possible role of local tissue hypoxia as a significant component of DAVF pathogenesis. Moreover, it has potential implications for MMA embolization as a management strategy for CSDH.
Purpose
To evaluate retrospectively safety and effectiveness of cervical vertebroplasty (cVP) based on a single-center large cohort.
Materials and methods
All cVP performed at a single center from ...January 2001 to October 2014 were included and reviewed. Procedure-related complications (minor and major) were systematically recorded. Effectiveness in terms of analgesia was evaluated using a semi-quantitative grading scale at 1-month follow-up. Risk factors for the occurrence of a procedure-related complication or cement leakage, as well as factors influencing pain relief at 1-month follow-up, were evaluated using a multivariate analysis.
Results
One hundred and forty cVP procedures (176 vertebrae) were performed in 130 consecutive patients (88 female, 42 male; mean age = 56 years) during the inclusion period. Among the treated lesions, 80% were bone metastases (mostly from breast cancer), 8% were related to hematological malignancies, and 12% were non-malignant lesions. One fatal complication (0.7%) was related to cement migration in the vertebrobasilar system. Three cervical hematomas were recorded, one of them requiring prolonged oral intubation. The overall rate of major complications was 1.5%. At 1 month, pain reduction was observed in 76% of the cases. Additional surgical fixation was required in 6.1% of the cases. cVP of more than one vertebra during the same session was an independent risk factor for procedure-related complications.
Conclusion
Cervical vertebroplasty is a safe technique with an acceptable major complication rate. Its effectiveness in terms of pain relief is good at mid-term follow-up.
Key Points
•
Cervical vertebroplasty (cVP) is a safe procedure with a low rate of major complications (1.5%).
•
cVP provides pain relief in 76% of the cases.
•
Additional fixation surgery is rarely required after cVP (6.1% of the cases).
Purpose
To assess the obliteration rate, functional outcome, hemorrhagic complication, and mortality rates of exclusion treatment of low-grade brain arteriovenous malformations (BAVMs) (Spetzler and ...Martin grades (SMGs) 1 and 2), either ruptured or unruptured.
Methods
Electronic databases—Ovid MEDLINE and PubMed—were searched for studies in which there was evidence of exclusion treatment of low-grade BAVMs treated either by endovascular, surgical, radiosurgical, or multimodality treatment. The primary outcome of interest was angiographic obliteration post-treatment and at follow-up. The secondary outcomes of interest were functional outcome (mRS), mortality rate, and hemorrhagic complication. Descriptive statistics were used to calculate rates and means.
Results
Eleven studies involving 1809 patients with low-grade BAVMs were included. Among these, 1790 patients treated by either endovascular, surgical, radiosurgical, or multimodality treatment were included in this analysis. Seventy-two percent of BAVMs were Spetzler-Martin grade II. The overall (i.e., including all exclusion treatment modalities) complete obliteration rate ranged from 36.5 to 100%. The overall symptomatic hemorrhagic complication rate ranged from 0 to 7.3%; procedure-related mortality ranged from 0 to 4.7%.
Conclusion
Our systematic review of the literature reveals a high overall obliteration rate for low-grade BAVMs, either ruptured or unruptured, with low mortality rate and an acceptable post-treatment hemorrhagic complication rate. These results suggest that exclusion treatment of low-grade BAVMs may be safe and effective, regardless of the treatment modality chosen.
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