The diagnostic value of quantitative analysis of ASL, DSC-MRI and DKI in the grading of cerebral gliomas: a meta-analysis

Quantitative analysis using intraoperative contrast-enhanced ultrasound in adult-type diffuse gliomas with isocitrate dehydrogenase mutations: association between hemodynamics and molecular features

PURPOSE

The relationship between contrast-enhanced ultrasound (CEUS) hemodynamics and the molecular biomarkers of adult-type diffuse gliomas, particularly isocitrate dehydrogenase (IDH), remains unclear. This study was conducted to provide a comprehensive description of the vascularization of adult-type diffuse gliomas using quantitative indicators. Additionally, it was designed to identify any variables with the potential to intraoperatively predict IDH mutation status.

METHODS

This prospective study enrolled patients with adult-type diffuse gliomas between November 2021 and September 2022. Intraoperative CEUS was performed, and CEUS videos were recorded for 90-second periods. Hemodynamic parameters, including the peak enhancement (PE) difference, were calculated based on the time-intensity curve of the region of interest. A differential analysis was performed on the CEUS parameters with respect to molecular biomarkers and grades. Receiver operating characteristic curves for various parameters were analyzed to evaluate the ability of those parameters to predict IDH mutation status.

RESULTS

Sixty patients with adult-type diffuse gliomas were evaluated. All hemodynamic parameters, apart from rising time, demonstrated significant differences between IDH-mutant and IDH-wildtype adult-type diffuse gliomas. The PE difference emerged as the optimal indicator for differentiating between IDH-wildtype and IDH-mutant gliomas, with an area under the curve of 0.958 (95% confidence interval, 0.406 to 0.785). Additionally, the hemodynamic parameters revealed significant differences across both grades and types of adult-type diffuse gliomas.

CONCLUSION

Hemodynamic parameters can be used intraoperatively to effectively distinguish between IDHwildtype and IDH-mutant adult-type diffuse gliomas. Additionally, quantitative CEUS equips neurosurgeons with dynamic perfusion information for various types and grades of adult-type diffuse gliomas.

The utility of arterial spin labelled perfusion-weighted magnetic resonance imaging in measuring the vascularity of high grade gliomas - A prospective study

Background

Dynamic susceptibility contrast (DSC) perfusion weighted imaging (PWI) currently remains the gold standard technique for measuring cerebral perfusion in glioma diagnosis and surveillance. Arterial spin labelling (ASL) PWI is a non-invasive alternative that does not require gadolinium contrast administration, although it is yet to be applied in widespread clinical practice. This study aims to assess the utility of measuring signal intensity in ASL PWI in predicting glioma vascularity by measuring maximal tumour signal intensity in patients based on pre-operative imaging and comparing this to maximal vessel density on histopathology.

Methods

Pseudocontinuous ASL (pCASL) and DSC images were acquired pre-operatively in 21 patients with high grade gliomas. The maximal signal intensity within the gliomas over a region of interest of 100 mm² was measured and also normalised to the contralateral cerebral cortex (nTBF-C), and cerebellum (nTBF-Cb). Maximal vessel density per 1 mm² was determined on histopathology using CD31 and CD34 immunostaining on all participants.

Results

Using ASL, statistically significant correlation was observed between maximal signal intensity (p < 0.05) and nTBF-C (p < 0.05) to maximal vessel density based on histopathology. Although a positive trend was also observed nTBF-Cb, this did not reach statistical significance. Using DSC, no statistically significant correlation was found between signal intensity, nTBF-C and nTBF-Cb. There was no correlation between maximal signal intensity between ASL and DSC. Average vessel density did not correlate with age, sex, previous treatment, or IDH status.

Conclusions

ASL PWI imaging is a reliable marker of evaluating the vascularity of high grade gliomas and may be used as an adjunct to DSC PWI.

Arterial spin labeling clinical applications for brain tumors and tumor treatment complications: A comprehensive case-based review

Arterial spin labeling (ASL) is a noninvasive neuroimaging technique that allows for quantifying cerebral blood flow without intravenous contrast. Various neurovascular disorders and tumors have cerebral blood flow alterations. Identifying these perfusion changes through ASL can aid in the diagnosis, especially in entities with normal structural imaging. In addition, complications of tumor treatment and tumor progression can also be monitored using ASL. In this case-based review, we demonstrate the clinical applications of ASL in diagnosing and monitoring brain tumors and treatment complications.

Anti-Vascular Endothelial Growth Factor Therapy Abolishes Glioma-Associated Endothelial Cell-Induced Tumor Invasion

Tumor-remodeled endothelial cells not only facilitate the formation of tumor angiogenesis but also promote tumorigenesis. In this study, we aimed to explore the interaction between glioma-associated endothelial cells (GAEs) and glioma cells. We found that different subtypes of glioma owned distinct GAE abundance. Glioma patients with high GAE abundance exhibited poor prognosis. Both the results of the bioinformatics analysis and the in vitro co-culture system assay revealed that GAE promoted glioma cell invasion. Besides, anti-vascular endothelial growth factor (VEGF) therapy partially abolished the effects of GAE on gliomas. Moreover, anti-VEGF therapy upregulated IL-2 expression in GAE, and exogenous IL-2 administration inhibits GAE-induced glioma cell invasion. Collectively, our present study provides a novel outstanding of the interaction between GAE and glioma cells.

Advanced Neuroimaging Approaches to Pediatric Brain Tumors

Simple Summary

After leukemias, brain tumors are the most common cancers in children, and early, accurate diagnosis is critical to improve patient outcomes. Beyond the conventional imaging methods of computed tomography (CT) and magnetic resonance imaging (MRI), advanced neuroimaging techniques capable of both structural and functional imaging are moving to the forefront to improve the early detection and differential diagnosis of tumors of the central nervous system. Here, we review recent developments in neuroimaging techniques for pediatric brain tumors.

Abstract

Central nervous system tumors are the most common pediatric solid tumors; they are also the most lethal. Unlike adults, childhood brain tumors are mostly primary in origin and differ in type, location and molecular signature. Tumor characteristics (incidence, location, and type) vary with age. Children present with a variety of symptoms, making early accurate diagnosis challenging. Neuroimaging is key in the initial diagnosis and monitoring of pediatric brain tumors. Conventional anatomic imaging approaches (computed tomography (CT) and magnetic resonance imaging (MRI)) are useful for tumor detection but have limited utility differentiating tumor types and grades. Advanced MRI techniques (diffusion-weighed imaging, diffusion tensor imaging, functional MRI, arterial spin labeling perfusion imaging, MR spectroscopy, and MR elastography) provide additional and improved structural and functional information. Combined with positron emission tomography (PET) and single-photon emission CT (SPECT), advanced techniques provide functional information on tumor metabolism and physiology through the use of radiotracer probes. Radiomics and radiogenomics offer promising insight into the prediction of tumor subtype, post-treatment response to treatment, and prognostication. In this paper, a brief review of pediatric brain cancers, by type, is provided with a comprehensive description of advanced imaging techniques including clinical applications that are currently utilized for the assessment and evaluation of pediatric brain tumors.

Assessment of brain tumors by magnetic resonance dynamic susceptibility contrast perfusion-weighted imaging and computed tomography perfusion: a comparison study

PURPOSE

To investigate the association and agreement between magnetic resonance dynamic susceptibility contrast perfusion-weighted imaging (DSC-PWI) and computed tomography perfusion (CTP) in determining vascularity and permeability of primary and secondary brain tumors.

MATERIAL AND METHODS

DSC-PWI and CTP studies from 97 patients with high-grade glioma, low-grade glioma and solitary brain metastasis were retrospectively reviewed. Normalized cerebral blood flow (nCBF), cerebral blood volume (nCBV), capillary transfer constant (nK2) and permeability surface area product (nPS) values were obtained. Variables among groups were compared, and correlation and agreement between DSC-PWI and CTP were tested.

RESULTS

All DSC-PWI and CTP parameters were higher in high-grade than in low-grade gliomas (p < 0.01 and p < 0.001). Metastases had greater DSC-PWI nCBV (p < 0.05), nCTP-CBF (p < 0.05), nCTP-CBV (p < 0.01) and nCTP-PS (p < 0.0001) than low-grade gliomas and more elevated nCTP-PS (p < 0.01) than high-grade gliomas. The correlation was strong between DSC-PWI nCBF and CTP nCBF (r = 0.79; p < 0.00001) and between DSC-PWI nCBV and CTP nCBV (r = 0.83; p < 0.00001), weaker between DSC-PWI nK2 and CTP nPS (r = 0.29; p < 0.01). Bland-Altman plots indicated that the agreement was strong between DSC-PWI nCBF and CTP nCBF, good between DSC-PWI nCBV and CTP nCBV and poorer between DSC-PWI nK2 and CTP nPS.

CONCLUSION

DSC-PWI and CTP CBF and CBV maps were comparable and interchangeable in the assessment of tumor vascularity, unlike DSC-PWI K2 and CTP PS maps that were more discordant in the analysis of tumor permeability. CTP could be an alternative method to quantify tumor neoangiogenesis when MRI is not available or when the patient does not tolerate it.

Hemodynamic Imaging in Cerebral Diffuse Glioma-Part A: Concept, Differential Diagnosis and Tumor Grading

Diffuse gliomas are the most common primary malignant intracranial neoplasms. Aside from the challenges pertaining to their treatment-glioblastomas, in particular, have a dismal prognosis and are currently incurable-their pre-operative assessment using standard neuroimaging has several drawbacks, including broad differentials diagnosis, imprecise characterization of tumor subtype and definition of its infiltration in the surrounding brain parenchyma for accurate resection planning. As the pathophysiological alterations of tumor tissue are tightly linked to an aberrant vascularization, advanced hemodynamic imaging, in addition to other innovative approaches, has attracted considerable interest as a means to improve diffuse glioma characterization. In the present part A of our two-review series, the fundamental concepts, techniques and parameters of hemodynamic imaging are discussed in conjunction with their potential role in the differential diagnosis and grading of diffuse gliomas. In particular, recent evidence on dynamic susceptibility contrast, dynamic contrast-enhanced and arterial spin labeling magnetic resonance imaging are reviewed together with perfusion-computed tomography. While these techniques have provided encouraging results in terms of their sensitivity and specificity, the limitations deriving from a lack of standardized acquisition and processing have prevented their widespread clinical adoption, with current efforts aimed at overcoming the existing barriers.

Primary application of mean apparent propagator-MRI diffusion model in the grading of diffuse glioma

PURPOSE

To evaluate the diagnostic -->performance of mean apparent propagator-magnetic resonance imaging (MAP-MRI) in distinguishing the grades of diffuse gliomas.

METHOD

Thirty-six patients with pathologically confirmed diffuse gliomas were enrolled in this study. MAP-MRI parameters were measured in the parenchymal area of the tumour: non-Gaussianity (NG), non-Gaussianity axial (NGAx), non-Gaussianity vertical (NGRad), Q-space inverse variance (QIV), return to the origin probability (RTOP), return to the axis probability (RTAP), return to the plane probability (RTPP), and mean square displacement (MSD). Differences in the parameters between any two grades were compared, the characteristics of the parameters for different diffuse glioma grades were analysed, and receiver operating characteristic (ROC) curves were plotted to analyse the diagnostic value of each parameter.

RESULTS

Compared with grade III gliomas, grade II gliomas had lower NG, NGAx and NGRad values. NG, NGAx and NGRad had great area under the ROC curve (AUC) values (0.823, 0.835, and 0.838, P < 0.05). Compared with those of grade IV glioma, the NG, NGAx, NGRad, RTAP and RTOP values for grade II glioma were lower, the QIV values were higher (all P < 0.05). NG, NGAx, NGRad, RTAP, RTOP and QIV had great area under the ROC curve (AUC) values (0.923, 0.929, 0.923,0.793,0.822, and 0.769, P < 0.05).

CONCLUSIONS

Quantitative MAP-MRI parameters can distinguish grade II and III and grade II and IV gliomas before surgery but not grade III and IV gliomas. Thus, these parameters have clinical guiding value in the noninvasive preoperative evaluation of tumour pathological grading.