Moyamoya disease (MMD) is a rare stenoocclusive cerebral vasculopathy often treated by neurosurgical revascularization using extracranial-intracranial bypasses to prevent ischemic or hemorrhagic ...events. Little is known about the vascular risk profile of adult MMD patients compared to the general population. We therefore analyzed 133 adult MMD patients and compared them with data from more than 22,000 patients from the German Health Update database. Patients with MMD showed an age- and sex-adjusted increased prevalence of arterial hypertension, especially in women between 30 and 44 years and in patients of both sexes between 45 and 64 years. Diabetes mellitus was diagnosed significantly more frequently in MMD patients with increasing age, whereas the vascular risk profile in terms of obesity, nicotine and alcohol consumption was similar to that of the general population. Antihypertensive medication was changed one year after surgical revascularization in 67.5% of patients with a tendency towards dose reduction in 43.2% of all patients. After revascularization, physicians need to be aware of a high likelihood of changes in arterial hypertension and should adjust all other modifiable systemic vascular risk factors to achieve the best treatment possible.
Objective: Image quality in high-field intraoperative MRI (iMRI) is often influenced negatively by susceptibility artifacts. While routine sequences are rather robust, advanced imaging such as ...diffusion-weighted imaging (DWI) is very sensitive to susceptibility resulting in insufficient imaging data. This study aims to analyze intraoperatively acquired DWI to identify the main factors for susceptibility, to compare results with postoperative images and to identify technical aspects for improvement of intraoperative DWI.
Methods: 100 patients with intraaxial lesions operated in a high-field iMRI were analyzed retrospectively for the quality of intraoperative DWI in comparison to the postoperative scan. General quality of the MR scan, individual diffusion restrictions, artifacts, and their causes were analyzed.
Results: Inclusion criteria were met in 78 patients, 124 diffusion restrictions were included in the comparative analysis. PPV and NPV for the detection of DWI changes intraoperatively were 0.94 and 0.56, respectively (SEN 0.94; SPE 0.56). Image quality was rated significantly (
p
< 0.0001) worse intraoperatively compared to the postoperative MRI. The main reasons for reduced image quality intraoperatively were air (64%) and artificial material (e.g., compress) (38%) in the resection cavity, as well as positioning of patient’s head outside the MR’s isocenter 37%. Analysis of surgical approaches showed that frontal craniotomies have the highest risk of limited image quality (40%), whereat better results (15% limited image quality) were seen for all other approaches (
p
= 0.059).
Conclusion: Intraoperative DWI showed reliable results in this analysis. However, image-quality was limited severely in many cases leading to uncertainty in the interpretation. Susceptibility-causing factors might be prevented in many cases, if the surgical team is aware of them. The most important factors are good filling of the resection cavity with irrigation fluid, not placing artificial materials in the resection cavity and adequate positioning of patient’s head according to the MR isocenter.
Introduction
The purpose of this study was to evaluate the feasibility of intravoxel incoherent motion (IVIM) imaging and its value in differentiating the histologic grade among human gliomas.
...Methods
The IVIM model generated parametric images for apparent diffusion coefficient ADC, slow diffusion coefficient
D
(or
D
slow
), fast diffusion coefficient
D
* (or
D
fast
), and fractional perfusion-related volume
f
in 22 patients with gliomas (WHO grade II–IV) using monopolar Stejskal–Tanner diffusion-weighted imaging (DWI) scheme and 14
b
values ranging from 0 s/mm
2
to a maximum of 1,300 s/mm
2
. A region-of-interest analysis on the tumor as well as in the white matter was conducted. The parameter values were tested for significant differences. The repeatability of the measurements was tested by coefficient of variation and Bland–Altman plots.
Results
D
,
D
*, and
f
in the high-grade gliomas demonstrated significant differences compared to the healthy white matter.
D
* and
f
showed a significant difference between low- and high-grade gliomas.
D
tended to be slightly lower in the WHO grade II compared to WHO grade III–IV tumors.
f
and
D
* demonstrated higher coefficients of variation than the ADC and
D
in tumor. The Bland–Altman plots demonstrated satisfactory results without any outliers outside the mean ± 1.96 standard deviation.
Conclusion
The IVIM-fitted post-processing of DWI-signal decay in human gliomas could show significantly different values of fractional perfusion-related volume and fast diffusion coefficient between low- and high-grade tumors, which might enable a noninvasive WHO grading in vivo.
Purpose
Patients with Moyamoya Angiopathy (MMA) require hemodynamic evaluation to assess the risk of stroke. Assessment of cerebral blood flow with
15
Owater PET and acetazolamide challenge is the ...diagnostic standard for the evaluation of the cerebral perfusion reserve (CPR). Estimation of the cerebrovascular reactivity (CVR) by use of breath-hold-triggered fMRI (bh-fMRI) as an index of CPR has been proposed as a reliable and more readily available approach. Recent findings suggest the use of resting-state fMRI (rs-fMRI) which requires minimum patient compliance. The aim of this study was to compare rs-fMRI to bh-fMRI and
15
Owater PET in patients with MMA.
Methods
Patients with MMA underwent rs-fMRI and bh-fMRI in the same MRI session. Maps of the CVR gained by both modalities were compared retrospectively by calculating the correlation between the mean CVR of 12 volumes of interest. Additionally, the rs-maps of a subgroup of patients were compared to CPR-maps gained by
15
Owater PET.
Results
The comparison of the rs-maps and the bh-maps of 24 patients revealed a good correlation (Pearson’s
r
= 0.71 ± 0.13; preoperative patients: Pearson’s
r
= 0.71 ± 0.17; postoperative patients: Pearson’s
r
= 0.71 ± 0.11). The comparison of 7 rs-fMRI data sets to the corresponding
15
Owater PET data sets also revealed a high level of agreement (Pearson’s
r
= 0.80 ± 0.19).
Conclusion
The present analysis indicates that rs-fMRI might be a promising non-invasive method with almost no patient cooperation needed to evaluate the CVR. Further prospective studies are required.
Saccular intracranial aneurysms are balloon-like dilations of the intracranial arterial wall; their hemorrhage commonly results in severe neurologic impairment and death. We report a second ...genome-wide association study with discovery and replication cohorts from Europe and Japan comprising 5,891 cases and 14,181 controls with ∼832,000 genotyped and imputed SNPs across discovery cohorts. We identified three new loci showing strong evidence for association with intracranial aneurysms in the combined dataset, including intervals near RBBP8 on 18q11.2 (odds ratio (OR) = 1.22, P = 1.1 × 10−12), STARD13-KL on 13q13.1 (OR = 1.20, P = 2.5 × 10−9) and a gene-rich region on 10q24.32 (OR = 1.29, P = 1.2 × 10−9). We also confirmed prior associations near SOX17 (8q11.23-q12.1; OR = 1.28, P = 1.3 × 10−12) and CDKN2A-CDKN2B (9p21.3; OR = 1.31, P = 1.5 × 10−22). It is noteworthy that several putative risk genes play a role in cell-cycle progression, potentially affecting the proliferation and senescence of progenitor-cell populations that are responsible for vascular formation and repair.
Introduction
Glioblastoma (GBM) is a tumor with rapid growth and a possible relationship to elevated intracranial pressure (ICP). High ICP may not always be associated with clinical signs. A ...non‐invasive technique for assessment of ICP is measuring the optic nerve sheath diameter (ONSD). Identifying patients who need immediate intervention is of importance in neuro‐oncological care. The goal of this study is to assess the available magnetic resonance imaging (MRI) of patients with GBM with respect to pre‐ and postoperative ONSD.
Methods and Materials
Retrospective data analysis was performed on all patients operated for GBM at a tertiary care center between 2010 and 2020. Two pre and one postoperative MRI had to be available. Clinical data and ONSD at multiple time points were analyzed and correlated, as well as preoperative volumetrics.
Results
Sixty‐seven patients met the inclusion criteria. Clinical signs of elevated ICP were seen in 25.4% (n = 17), while significant perifocal edema was present in 67.2% (n = 45) of patients. Clinical signs of preoperatively elevated ICP were associated with significantly elevated ONSD at diagnosis (p < 0.001) as well as preoperative tumor volume (p < 0.001). Significant perifocal edema at the time of diagnosis was associated with elevated ONSD (p = 0.029) and higher tumor volume (p = 0.003). In patients with significant edema, ONSD increased significantly between preoperative MRIs (p = 0.003/005). In patients with clinical signs of raised ICP, ONSD also increased, whereas it was stable in asymptomatic patients (yes: 5.01+/−4.17 to 5.83+/−0.55 mm, p = 0.010, no: 5.17+/−0.46 mm to 5.38+/−0.41 mm, p = 0.81). A significant increase of ONSD from diagnosis to preoperative MRI and a significant decrease until 3 months postoperatively were observed (p < 0.001).
Conclusions
ONSD might help identify high ICP in patients with GBM. In this first‐of‐its kind study, we observed a significant increase of ONSD preoperatively, likely associated with edema. Postoperatively, ONSD decreased significantly until 3 months after surgery and increased again at 12 months. Further prospective data collection is warranted.
Measurement of optical nerve sheath diameter (ONSD) is a noninvasive technique for assessment of intracranial pressure. Identifying patients at risk with the need of immediate intervention is of importance in neuro‐oncological care. This study retrospectively investigates pre‐ and postoperative ONSD in patients with glioblastoma.
Purpose
To assess the prevalence of false-positive meningeal contrast enhancement in patients with solid tumors who were undergoing chemotherapy.
Methods
A total of 2572 magnetic resonance imaging ...(MRI) examinations of the brain were retrospectively evaluated by two readers for the presence of pathological meningeal contrast enhancement conspicuous for neoplastic meningitis. These patients either had malignant melanoma, breast or lung cancer, or lymphoma. The reference standards were cerebrospinal fluid cytology results and follow-up MRI. In cases with pathological contrast enhancement that decreased upon follow-up and non-malignant cytology, the enhancement pattern was further described as pial or dural, local or diffuse, or supra- or infra-tentorial. Moreover, the underlying therapy regimes were assessed.
Results
The final study cohort included 78 patients (51 females, median age 57 years), of which 11 patients (14.1%) had a repeated non-malignant cytology (‘pseudomeningeosis’). In one case, this finding, a granular pleocytosis, was attributed to previous radiotherapy. Of the remaining patients, seven were receiving multimodal, immunotherapy-based therapy regimens. Patients with unsuspicious cytology had a predominantly supratentorial distribution pattern in comparison to patients with neoplastic meningitis.
Conclusions
The overall prevalence of the presence of false-positive meningeal contrast enhancement is low (< 1%) and not associated with specific imaging patterns. We hypothesize that there is a possible relationship between immunotherapy and ‘pseudomeningeosis’. Therefore, in all cases with suspected neoplastic meningitis, the cerebrospinal fluid should be analyzed to confirm the diagnosis, especially in patients undergoing immunotherapy.
To show that the combined use of intraoperative high-field MRI (iMRI) and electrophysiologic monitoring (IOM) is feasible, safe, and beneficial for patients.
The setup, surgical, imaging, and ...clinical results of 110 patients with eloquent intracranial lesions with the combined use of 1.5T iMRI and IOM were analyzed.
187 iMRI scans were performed with IOM needles in place, resulting in a total experience of using >4000 electrodes in the iMRI. No complication (ferromagnetic or relevant heating/burning of skin) was caused by the combined use of both technologies. Surgically induced severe postoperative sensorimotor deficits were seen in 11.8%. The surgeon's estimation of a “complete resection” proved to be true postoperatively in 90.3%. If the resection was stopped due to worsening of IOM, postoperative MRI revealed residual disease to be located in direct vicinity of eloquence in 27 of 28 cases, but not in other parts of the resection cavity. Of these patients, only 7% (2 of 28) had relevant new deficits after 3 months. In 82 patients (74.5%), the resection was continued after the iMRI scan, whereas in only 18 patients (16.4%) the resection was already completed at this point.
The combined use of IOM and 1.5T iMRI is feasible and safe. The complementary use of both technologies might result in more radical resections at comparable surgically induced neurologic deficits. If available and indicated, the combined use of IOM and iMRI should be performed on a routine basis.
In children with bladder/prostate (BP) and perianal rhabdomyosarcoma (RMS), we use a hybrid treatment concept for those suitable, combining organ-preserving tumor resection and high-dose rate ...brachytherapy (HDR-BT). This treatment concept has been shown to improve outcomes. However, it is associated with specific challenges for the clinicians. The exact position of the tubes for BT is a prerequisite for precise radiotherapy. It can finally be determined only with an MRI or CT scan. We evaluated the use of an intraoperative MRI (iMRI) to control the position of the BT tubes and for radiotherapy planning in all patients with BP and perianal RMS who received the above-mentioned combination therapy in our department since January 2021. iMRI was used in 12 children. All tubes were clearly localized. No adverse events occurred. In all 12 children, radiotherapy could be started on time. In a historical cohort without iMRI, this was not possible in 3 out of 20 children. The use of iMRI in children with BP and perianal RMS improved patient safety and treatment quality. This technology has proven to be successful for the patient population we have defined and has become a standard procedure in our institution.
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