Hanno S. Meyer

Background: Delayed cerebral ischaemia remains a major cause of secondary brain injury after aneurysmal subarachnoid haemorrhage (aSAH). Although computed tomography perfusion (CTP) is widely used for vasospasm surveillance, perfusion abnormalities are commonly reported only as present or absent, potentially overlooking the prognostic relevance of their extent. We investigated whether a territory-based perfusion burden score is associated with outcome more closely than binary perfusion deficit assessment. Methods: This retrospective single-centre cohort study included 179 patients with aSAH who underwent at least one CTP examination during hospitalization. CTP was performed according to clinical indication rather than at predefined time points; 448 examinations were evaluated. Two blinded neuroradiologists assigned one point per affected vascular territory (score range 0–12), and the maximum score during hospitalization was analysed. Outcomes were functional outcome at 6 months (modified Rankin Scale 0–2 versus 3–6), new cerebral infarction at discharge, and in-hospital mortality. Multivariable logistic regression models were built by forward selection from prespecified covariates (age, Hunt and Hess grade, modified Fisher grade, intracerebral haemorrhage, external ventricular drainage, and aneurysm treatment modality). Results: Territorial perfusion burden was independently associated with poor functional outcome (adjusted odds ratio 1.17 per point, 95% confidence interval 1.02–1.33) and new cerebral infarction (adjusted odds ratio 1.36 per point, 95% confidence interval 1.19–1.55). Any perfusion deficit was associated with new infarction (odds ratio 8.88, 95% confidence interval 3.31–23.87) but not with functional outcome. Conclusions: In this selected cohort under CTP surveillance, the extent of perfusion impairment was associated with functional outcome and infarction, whereas binary deficit assessment was associated with infarction only. These preliminary findings suggest that territorial perfusion burden may refine risk stratification, but prospective validation with standardized imaging time points is required before the score can be used as a prognostic tool.

Background: Cerebral vasospasm (CV) as a complication after aneurysmal subarachnoid hemorrhage (aSAH) is a major determinant of secondary vasospasm-associated ischemic infarction (SVS-I) and poor outcome. Data on the interplay among the onset of CV, SVS-I, and in-hospital mortality remain limited. Methods: We conducted a retrospective, single-center study including patients admitted with aSAH between January 2016 and May 2024 who developed treatment-relevant CV. The primary outcome was the rate of in-hospital mortality. The relationship between the onset of CV, demographics, imaging, and treatment data and the primary outcome was analyzed using logistic regression. A confounder-adjusted mediation analysis was performed to quantify the extent to which the effect of time to CV onset on in-hospital mortality was mediated by SVS-I. Results: A total of 165 patients with aSAH and treatment-relevant CV were included. The median age was 55 (IQR, 48–64), and 67.2% (111) were female. Of the included patients, 13.3% (22) died during hospitalization. In multivariable logistic regression analysis, earlier onset of treatment-relevant CV (adjusted odds ratio [aOR] 0.79; 95% CI, 0.66–0.95) and the occurrence of SVS-I (aOR 13.47; 95% CI, 2.78–65.3) were associated with the primary outcome. Mediation analysis indicated that SVS-I accounted for 28% of the effect of earlier onset of CV on in-hospital mortality. Conclusions: Twenty-eight percent of the effect of earlier onset of cerebral vasospasm on in-hospital mortality was mediated by secondary ischemic infarction. Targeting patients with early-onset vasospasm and the associated risk of infarction may reduce in-hospital mortality following aneurysmal subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: Cerebral vasospasm remains a strong predictor of poor outcomes after aneurysmal subarachnoid hemorrhage (aSAH). Endovascular treatment of vasospasm can be considered when conservative treatment options are exhausted, but its superiority over standard treatment remains a subject of critical debate. This study focuses on patients with clinically relevant vasospasm after aSAH who underwent endovascular vasospasm treatment and aims to analyze patients’ individual risk factors, intensity, and extent of cerebral vasospasm associated with poor functional outcomes after aSAH. MATERIALS AND METHODS: We conducted a retrospective cohort study of consecutive patients with aSAH admitted at a tertiary stroke center between January 2016 and December 2022. Patients with medically refractory cerebral vasospasm necessitating at least 1 endovascular intervention were analyzed. Primary end point was defined as functional outcome defined as modified Rankin Scale (mRS) scores after 6 months. Secondary end point was the occurrence of cerebral infarctions following cerebral vasospasm. RESULTS: Overall, 138 patients received endovascular treatment due to cerebral vasospasm, including 322 treatments, with 78 patients receiving more than 1 endovascular treatment. In 65.2% (90) of patients, cerebral vasospasm developed in both hemispheres; in 16.7% (23), cerebral vasospasm occurred involving the posterior circulation; and in 10.1% (14), percutaneous transluminal angioplasty was performed. Multivariable logistic regression analysis showed an association of higher age (adjusted odds ratio [aOR], 1.05, 95% CI: 1.0–1.1), higher Hunt and Hess grades (aOR, 2.12, 95% CI: 1.38–3.24), the occurrence of rebleeding (aOR, 4.97, 95% CI: 1.0–24.65), and bihemispheric vasospasm (aOR, 4.05, 95% CI: 1.4–11.72) with unfavorable outcome (mRS 3–6). Further analysis showed that higher age (aOR, 1.07, 95% CI: 1.03–1.13) was associated with an increased risk of developing vasospasm-associated infarctions. CONCLUSIONS: Our results indicate an association between bihemispheric cerebral vasospasm and poor functional outcomes after aSAH. This finding supports a more aggressive treatment strategy in patients developing bihemispheric vasospasm to prevent unfavorable disease courses.

Introduction: Cerebral vasospasms remain a strong predictor of poor outcome after aneurysmal SAH. The aim of this study was to describe the time course of relevant vasospasms after aneurysmal SAH and to determine the variables associated with early-onset or prolonged and recurrent vasospasms. Patients and methods: We conducted a retrospective, single-center study of consecutive adult patients with aneurysmal SAH admitted between 2016 and 2022 at our tertiary stroke center. Relevant vasospasms, defined as vessel narrowing detected in DSA in combination with clinical deterioration or new perfusion deficit, were detected according to our in-house algorithm and eventually treated endovascularly. The primary endpoint was the diagnosis of relevant vasospasms. As secondary endpoints, the time from hemorrhage to the onset of vasospasms and the time from the first to the last endovascular intervention were measured. Results: Of 368 patients with aneurysmal SAH, 135 (41.0%) developed relevant vasospasms. The median time between ictus and detection of vasospasms was 8 days (IQR: 6–10). Patients with early-onset vasospasms were significantly younger (mean 52.7 ± 11.2 years vs 58.7 ± 11.5 years, p = 0.003) and presented more frequently vasospasm-related infarctions at discharge (58.8% vs 38.7%, p = 0.03). In 74 patients (54.8%), recurrent relevant vasospasms were observed despite endovascular treatment. Younger age and early onset were significantly associated with longer duration of relevant vasospasms (both p < 0.05). Discussion and conclusion: Younger age was associated with early-onset and longer duration of relevant vasospasms in this study. More frequent clinical and diagnostic follow-up should be considered in this subgroup of patients that are at risk for poor outcomes.

BACKGROUND AND PURPOSE: Cerebral vasospasm is a common complication of aneurysmal SAH and remains a risk factor for delayed cerebral ischemia and poor outcome. The interrater reliability of CTA in combination with CTP has not been sufficiently studied. We aimed to investigate the reliability of CTA alone and in combination with CTP in the detection of cerebral vasospasm and the decision to initiate endovascular treatment. MATERIALS AND METHODS: This is a retrospective single-center study including patients treated for aneurysmal SAH. Inclusion criteria were a baseline CTA and follow-up imaging including CTP due to suspected vasospasm. Three neuroradiologists were asked to grade 15 intracranial arterial segments in 71 cases using a tripartite scale (no, mild 50% vasospasm). Raters further evaluated whether endovascular treatment should be indicated. The ratings were performed in 2 stages with a minimum interval of 6 weeks. The first rating included only CTA images, whereas the second rating additionally encompassed CTP images. All raters were blinded to any clinical information of the patients. RESULTS: Interrater reliability for per-segment analysis of vessels was highly variable (κ = 0.16–0.61). We observed a tendency toward higher interrater reliability in proximal vessel segments, except for the ICA. CTP did not improve the reliability for the per-segment analysis. When focusing on senior raters, the addition of CTP images resulted in higher interrater reliability for severe vasospasm (κ = 0.28; 95% CI, 0.10–0.46 versus κ = 0.46; 95% CI, 0.26–0.66) and subsequently higher concordance (κ = 0.23; 95% CI, −0.01–0.46 versus κ = 0.73; 95% CI, 0.55–0.91) for the decision of whether endovascular treatment was indicated. CONCLUSIONS: CTA alone offers only low interrater reliability in the graduation of cerebral vasospasm. However, using CTA in combination with CTP might help, especially senior neuroradiologists, to increase the interrater reliability to identify severe vasospasm following aneurysmal SAH and to increase the reliability regarding endovascular treatment decisions.

Introduction: The mesial temporal lobe plays a distinct role in epileptogenesis, and tumors in this part of the brain potentially have specific clinical and radiological features. Differentiating high-grade from lower-grade tumors or non-neoplastic lesions can be challenging, preventing the decision for early resection that can be critical in high-grade tumors.Methods: A brain tumor database was analyzed retrospectively to identify patients with temporomesial tumors. We determined clinical features (age, sex, symptoms leading to clinical presentation) as well as neuroradiological (tumor location and the presence of contrast enhancement on initial magnetic resonance imaging (MRI)) and neuropathological findings.Results: We identified 324 temporal tumors. 39 involved the mesial temporal lobe. 77% of temporomesial tumors occured in males, and 77% presented with seizures, regardless of tumor type or grade. In patients 50 years or older, 90% were male and 80% had glioblastoma (GBM); there was no GBM in patients younger than 50 years. 50% of GBMs lacked contrast enhancement. Male sex was significantly associated with GBM. In both contrast-enhancing and non-enhancing tumors, age of 50 years or older was also significantly associated with GBM.Conclusion: In middle-aged and older patients with a mesial temporal lobe tumor, GBM is the most likely diagnosis even when there is no MRI contrast enhancement. Prolonged diagnostic workup or surveillance strategies should be avoided and early resection may be justified in these patients.

Background: In diffusely infiltrating gliomas, the maximum extent of tumor resection is an important predictor of overall survival, irrespective of histological or molecular subtype or tumor grade. For glioblastoma WHO grade 4 (GBM), it has been shown that resection-related events, such as ventricular opening and ventriculitis, increase the risk for development of communicating hydrocephalus (CH) requiring cerebrospinal fluid (CSF) diversion surgery. Risk factors for the development and the incidence of hydrocephalus following resection of other types of infiltrating gliomas are less well established. In this study, we evaluated the incidence and timing of occurrence of different types of hydrocephalus and potential risk factors for the development of CH following resection of grade 2 and 3 gliomas. Methods: 346 patients who underwent tumor resection (WHO grade 2: 42.2%; 3: 57.8%) at our department between 2006 and 2019 were analyzed retrospectively. For each patient, age, sex, WHO grade, histological type, IDH mutation and 1p/19q codeletion status, tumor localization, number of resections, rebleeding, ventriculitis, ventricular opening during resection and postoperative CSF leak were determined. Uni- as well as multivariate analyses were performed to identify associations with CH and independent risk factors. Results: 24 out of 346 (6.9%) patients needed CSF diversion surgery (implantation of a ventriculoperitoneal or ventriculoatrial shunt) following resection. Nineteen patients (5.5%) had CH, on median, 44 days after the last resection (interquartile range: 18–89 days). Two patients had obstructive hydrocephalus (OH), and three patients had other CSF circulation disorders. CH was more frequent in grade 3 compared to grade 2 gliomas (8.5 vs. 1.4%). WHO grade 3 (odds ratio (OR) 7.5, p = 0.00468), rebleeding (OR 5.0, p = 0.00984), ventriculitis (OR 4.1, p = 0.00463) and infratentorial tumor localization (OR 6.6, p = 0.00300) were identified as significant independent risk factors for the development of post-resection CH. Ventricular opening was significantly associated with CH, but it was not an independent risk factor. Conclusion: Physicians treating brain tumor patients should be aware that postoperative CH requiring CSF shunting occurs not only in GBM but also after resection of lower-grade gliomas, especially in grade 3 tumors. It usually occurs several weeks after resection. Rebleeding and postoperative ventriculitis are independent risk factors.

Background: The fifth version of the World Health Organization (WHO) classification of tumors of the central nervous system (CNS) in 2021 brought substantial changes. Driven by the enhanced implementation of molecular characterization, some diagnoses were adapted while others were newly introduced. How these changes are reflected in imaging features remains scarcely investigated. Materials and Methods: We retrospectively analyzed 226 treatment-naive primary brain tumor patients from our institution who received extensive molecular characterization by epigenome-wide methylation microarray and were diagnosed according to the 2021 WHO brain tumor classification. From multimodal preoperative 3T MRI scans, we extracted imaging metrics via a fully automated, AI-based image segmentation and processing pipeline. Subsequently, we examined differences in imaging features between the three main glioma entities (glioblastoma, astrocytoma, and oligodendroglioma) and particularly investigated new entities such as astrocytoma, WHO grade 4. Results: Our results confirm prior studies that found significantly higher median CBV (p = 0.00003, ANOVA) and lower median ADC in contrast-enhancing areas of glioblastomas, compared to astrocytomas and oligodendrogliomas (p = 0.41333, ANOVA). Interestingly, molecularly defined glioblastoma, which usually does not contain contrast-enhancing areas, also shows significantly higher CBV values in the non-enhancing tumor than common glioblastoma and astrocytoma grade 4 (p = 0.01309, ANOVA). Conclusions: This work provides extensive insights into the imaging features of gliomas in light of the new 2021 WHO CNS tumor classification. Advanced imaging shows promise in visualizing tumor biology and improving the diagnosis of brain tumor patients.

Both positron emission tomography (PET) and magnetic resonance imaging (MRI), including dynamic susceptibility contrast perfusion (DSC-PWI), are crucial for treatment monitoring of patients with high-grade gliomas. In clinical practice, they are usually conducted at separate time points. Whether this affects their diagnostic performance is presently unclear. To this end, we retrospectively reviewed 38 patients with pathologically confirmed glioblastoma (IDH wild-type) and suspected tumor recurrence after radiotherapy. Only patients who received both a PET–MRI (where DSC perfusion was acquired simultaneously with a FET-PET) and a separate MRI exam (including DSC perfusion) were included. Tumors were automatically segmented into contrast-enhancing tumor (CET), necrosis, and edema. To compare the simultaneous as well as the sequential DSC perfusion to the FET-PET, we calculated Dice overlap, global mutual information as well as voxel-wise Spearman correlation of hotspot areas. For the joint assessment of PET and MRI, we computed logistic regression models for the differentiation between true progression (PD) and treatment-related changes (TRC) using simultaneously or sequentially acquired images as input data. We observed no significant differences between Dice overlap (p = 0.17; paired t-test), mutual information (p = 0.18; paired t-test) and Spearman correlation (p = 0.90; paired t-test) when comparing simultaneous PET–MRI and sequential PET/MRI acquisition. This also held true for the subgroup of patients with >14 days between exams. Importantly, for the diagnostic performance, ROC analysis showed similar AUCs for differentiation of PD and TRC (AUC simultaneous PET: 0.77; AUC sequential PET: 0.78; p = 0.83, DeLong’s test). We found no relevant differences between simultaneous and sequential acquisition of FET-PET and DSC perfusion, also regarding their diagnostic performance. Given the increasing attention to multi-parametric assessment of glioma treatment response, our results reassuringly suggest that sequential acquisition is clinically and scientifically acceptable.