Fig. 3

Imaging of low-grades glioma (6 different cases) by MRI with contrast, CT with contrast and IOUS. All lesions are not enhanced in CT and MRI images. Cases a, b, c: White arrows refer to calcifications (hyper-dense in CT and hyper-echogenic in IOUS). Case d: Pilocytic astrocytoma; arrows 1 refer to large cystic part, arrows 2 refer to small fleshy part with best delineation in IOUS images. Cases e, f: Astrocytoma grade 2; arrows 3 refer to the fleshy lesion which appeared hypo-intense in MRI T1, hypo-dense in CT and hyper-echogenic with best delineation in IOUS. The ultrasound criteria of low-grades tumors as noted in these cases are calcifications a, b, c, regular contours, hyper-echogenicity, homogeneity, single cyst (d), and few amount of brain edema