Susceptibility-Weighted Imaging in Preoperative Grading of Cerebral Gliomas

Gliomas are the most common primary brain tumors in adults. Determining whether a glioma is low-grade or high-grade before surgery is essential for surgical planning, choosing treatment pathways, and determining prognosis. Currently, definitive grading requires invasive tissue sampling through surgical resection or biopsy. Although conventional magnetic resonance imaging (MRI) is routinely performed, conventional sequences often show overlapping features between low-grade and high-grade tumors, limiting their ability to reliably predict tumor grade.

Susceptibility-weighted imaging (SWI) is an advanced MRI sequence sensitive to microscopic magnetic field distortions caused by blood products, calcification, and abnormal tumor blood vessels. On SWI, these features appear as intratumoral susceptibility signals (ITSS). Because high-grade gliomas typically display greater vascular proliferation and microhemorrhages than low-grade gliomas, quantifying ITSS may provide a non-invasive surrogate for tumor grade.

The primary purpose of this prospective observational study is to assess the diagnostic accuracy of SWI in the preoperative grading of cerebral gliomas, comparing imaging findings directly against histopathological examination according to the 2021 World Health Organization (WHO) Classification of Tumors of the Central Nervous System.

Adult participants with radiologically suspected cerebral gliomas who are scheduled for surgical resection or stereotactic biopsy will undergo a standardized preoperative brain MRI protocol. This protocol incorporates SWI alongside conventional MRI sequences, diffusion-weighted imaging (DWI/ADC), and magnetic resonance spectroscopy (MRS). Two independent radiologists blinded to pathology will assess and grade intratumoral susceptibility signals. Following surgery, imaging-predicted grades will be compared with the final tissue pathology to determine the sensitivity, specificity, and overall diagnostic accuracy of SWI.