Intraoperative sonography in low-grade gliomas.

A retrospective study of intraoperative sonography and preoperative head computed tomography (CT) in 15 patients with low-grade brain gliomas was undertaken to determine whether areas of increased echogenicity without shadowing corresponded with areas of pathologic CT enhancement. Glioma echogenicity was considered increased if greater than or equal to adjacent sulcal echogenicity. Of the 15 lesions, 7 of 8 with pathologic CT enhancement showed areas of increased echogenicity without shadowing. Areas of increased echogenicity topographically correlated with areas of pathologic CT enhancement. One of eight lesions with pathologic enhancement had no areas of increased echogenicity; however, the enhancement in this lesion was minimal. Six of seven patients without pathologic CT enhancement had areas of echogenicity always less than sulcal echogenicity. Our results suggest that, in low-grade gliomas, regions of enhancement usually correspond to areas of increased echogenicity without shadowing. These findings differ from those found with high-grade gliomas.