Application of intraoperative B-mode ultrasound and shear wave elastography for glioma grading

To evaluate the value of intraoperative B-mode ultrasound and shear wave elastography (SWE) in differentiating low-grade and high-grade gliomas.

A total of 172 patients with glioma were examined by B-mode ultrasound to obtain a tumor sonogram. Intraoperative SWE was performed on 52 patients to obtain Young's modulus values of peritumor tissue and tumor tissue, and the differences in conventional B-mode signs and Young's modulus values of gliomas of different grades were then compared. The diagnostic performance of SWE in glioma grading was assessed by receiver operating characteristic (ROC) curve analysis, and the intra- and interobserver reliability of SWE was analyzed by the intraclass correlation coefficient (ICC).

For B-mode ultrasound, patient age, cystic degeneration, and peritumor edema were independent risk factors for high-grade glioma (P<0.05, OR >1). For SWE, Young's modulus values of peritumor tissue, low-grade glioma, and high-grade glioma tissues were 8.20 (7.50, 9.70) kPa, 19.65 (15.30, 24.75) kPa, and 9.55 (8.50, 13.80) kPa, respectively. The area under the ROC curve for the diagnosis of high-grade glioma by SWE was 0.859 (95% CI: 0.758-0.961, P<0.05), and the optimal cutoff value was 12.1 kPa, with 89.3% sensitivity and 75.0% specificity. The intra- and interobserver reliability of SWE in grading gliomas was excellent, with ICCs ranging from 0.921 to 0.965.

High-grade glioma is associated with significantly more severe necrotic cystic degeneration and peritumoral edema on B-mode ultrasound and lower stiffness on SWE. Further, SWE exhibits excellent intra- and interobserver reliability. Intraoperative B-mode ultrasound combined with SWE helps differentiate different grades of gliomas.