Correlative assessment of tumor microcirculation using contrast-enhanced perfusion MRI and intravoxel incoherent...

Area of Science:

• Radiology
• Oncology
• Medical Imaging

Background:

• Intravoxel incoherent motion (IVIM) imaging offers insights into microvascular properties.
• Classical perfusion-weighted MRI metrics like dynamic contrast-enhanced (DCE) and dynamic susceptibility contrast-enhanced (DSC) are established for evaluating brain tumors.
• Understanding the relationship between these advanced and classical techniques is crucial for accurate glioma assessment.

Purpose of the Study:

• To correlate intravoxel incoherent motion (IVIM) imaging parameters with classical perfusion-weighted MRI metrics in human gliomas.
• To investigate differences in IVIM parameters across glioma grades.
• To explore correlations between IVIM parameters and DCE/DSC-derived metrics in both healthy and tumor tissues.

Main Methods:

• Generation of parametric images for IVIM parameters (D, D*, f) and DCE/DSC parameters (Fp, vp, PS, ve, E, ke, tc).
• Region-of-interest analysis in contralateral healthy white matter and tumor areas.
• Statistical testing for significant differences among tumor grades and correlations between IVIM and perfusion metrics.

Main Results:

• The fractional perfusion-related volume (f) from IVIM showed significant correlation with DSC-derived vascular plasma volume (vp) and vascular transit time (tc) in healthy brain tissue.
• In tumor regions, plasma flow (Fp) positively correlated with the fast diffusion coefficient (D*) and inversely with f from DSC.
• No significant differences were observed in D*, f, and f × D* between WHO grade III and IV gliomas. Trends for negative correlations between f and PS, and f × D* and ke were noted in DCE experiments.

Conclusions:

• IVIM imaging demonstrates limited correlation with conventional DCE and DSC MRI metrics in human gliomas.
• The distinct theoretical underpinnings and modeling of tumor vasculature may explain the lack of a clear, direct link between IVIM and traditional perfusion parameters.
• Further research is needed to elucidate the combined utility of IVIM and perfusion MRI for glioma characterization.