Investigation of histological heterogeneity based on the discrepancy between the hyperintense area on T2-weighted images and the accumulation area on 11C-methionine PET in minimally enhancing glioma

•Low grade glioma that shows hyper intense area on T2 weighted MRI or FLAIR imaging.•MET-PET reflects the extent of glioma cell invasion, but does not coincide with MRI.•The pathological heterogeneity may reflect the images discrepancy of MET-PET and MRI.•The understanding of this relevance is useful for correct diagnosis and surgical planning. The objective of the study was to investigate the correlation between differences between imaging modalities and histological heterogeneity in minimally enhancing glioma. A prospective study was performed in 11 patients with minimally enhancing glioma (10%. The correlation between the imaging discrepancy and histological heterogeneity was investigated. The average T/N ratio for the T2/FL+/MET+ area in grade II glioma (2.08 ± 0.4) was smaller than that in grade III (4.19 ± 2.4), whereas that for the T2/FL+/MET− area was similar in grade II (1.07 ± 0.2) and III (1.07 ± 0.1). The average T/N ratio for the T2/FL+/MET+ area in grade II and III was higher than that for the T2/FL+/MET− area (p