Objective      To investigate the correlation between the MR image of peritumoral edema and pathological subtype of convex surface and small meningioma.       Methods      Clinical data of 46 patients with histologicallyproven convex surface small meningioma (11 males and 35 females) who received surgery in our hospital during May 2008 to December 2011 were enrolled in this study. Their preoperative MR images were collected and retrospectively analyzed with their clinical data.       Results      In our series of 46 cases of meningiomas

most MR findings are isointensity on T

1

WI and T

2

WI

and the enhanced T

1

WI are obvious and homogeneous enhance

ment. There were 23 cases (50%) showing peritumoral edema. But there was no correlation of degree of peritumoral edema with different patholoical subtypes. The patholoical subtypes with larger diameter of peritumoral edema was as following in a descending order: angiomatous

microcystic

fibrous

meningothelial

mixed

and psammomatous. But no edema was found in rhabdoid

chordoid and papillary meningiomas.       Conclusion      MR imaging could show the peritumoral edema. Various pathological subtypes of meningiomas have different mechanisms of peritumoral edema.