Intraoperative superb microvascular ultrasound imaging in glioma: novel quantitative analysis correlates with tumour grade

Background

Accurate grading of gliomas is critical to guide therapy and predict prognosis. The presence of microvascular proliferation is a hallmark feature of high grade gliomas which to directly visualise traditionally requires targeted surgical biopsy of representative tissue. Superb microvascular imaging (SMI) is a novel high resolution Doppler ultrasound technique which can uniquely define the microvascular architecture of whole tumours.

Methods

We examined both qualitative and quantitative vascular features of 32 gliomas captured with SMI, analysing flow signal density, vessel number, branching points, curvature, vessel angle deviation, fractal dimension, and entropy.

Results

High-grade gliomas exhibit significantly greater vascular complexity and disorganisation, with increased fractal dimension and entropy, correlating with known histopathological markers of aggressive angiogenesis. The integrated ROC model achieved high accuracy (AUC = 0.95).

Conclusions

This study leveraged SMI to provide further insights into the microvascular architecture of gliomas which is not resolvable by magnetic resonance imaging. Applying novel quantitative analysis the study demonstrated that there are quantifiable differences in vascular morphology between high grade and low-grade gliomas. This unique in vivo imaging of glioma vascularity and quantification warrants further exploration as a potential new diagnostic and prognostic tool that may support glioma management, intraoperative decision-making and informing future prognosis.