Stiffness and Tissue Viscosity in a Cerebral Neoplasm Measured by Preoperative Multifrequency Magnetic Resonance Elastography (MRE) Guide the Differential Diagnosis of Brain Tumors by Ruling Out Glioma.

Here, we report the case of a 65-year-old man who presented to the emergency department with paresthesia, psychomotor retardation, and dysarthria. Contrast-enhanced brain MRI revealed a solitary, contrast-enhancing mass in the right head of the caudate nucleus with extensive perifocal edema, raising a primary differential diagnosis of glioblastoma versus metastasis, among other possibilities. Prior to surgical removal of the suspected glioblastoma, the patient underwent additional diffusion tensor imaging and research MRI, including multifrequency magnetic resonance elastography (MRE) to generate mechanical property maps of stiffness and tissue viscosity and to potentially differentiate between glioma, brain metastases, and benign masses based on tissue biomechanical properties. MRE revealed abnormally high values of stiffness and viscosity-a mechanical signature known to be associated with brain metastases or meningioma, but not glioblastoma, which typically exhibits soft tissue properties with reduced viscous dissipation. Histopathologic evaluation confirmed MRE by revealing a distant metastasis of squamous cell carcinoma, the primary tumor of which was detected by PET-CT within the right hilus of the lung. This case demonstrates the diagnostic value of the biomechanical properties of brain tumors and raises the prospect of applying MRE as an easy-to-use MRI contrast that can rule out glioma when the suspicious lesion exhibits stiff-viscous material properties.