Meningiomas: Correlation between MRI characteristics and operative findings including consistency

Abstract

The findings on magnetic resonance imaging (MRI) in 73 surgically verified intracranial meningiomas were correlated with their histology and consistency during resection. T 1-weighted imaging was least useful since most of the tumours were iso-intense, similar to cortical grey matter regardless of histology or tumour consistency. The signal intensity on T2-weighted images was found to best correlate with both the histology and consistency of the meningioma. Generally, the low intensity portion of the tumour on T2-weighted images indicated a more fibrous and harder character, while the higher intensity portions indicated a more soft character. Most of the fibroblastic meningiomas showed the features of a hard tumour while angioblastic tumours showed the features of soft tumours. Tumours predicted to be harder on MR imaging generally took longer to resect than softer ones, and this relationship was shown best for the larger tumours. Using linear regression analysis, it appears that operative time for soft tumours is more affected by factors other than tumour consistency. Blood loss during surgery was also unrelated to the consistency of the tumour. These results suggest that the histology and consistency of meningiomas may be predictable from findings on T2-weighted imaging, and this may also predict the difficulty and time required for resection.

A proposed grading system for standardizing tumor consistency of intracranial meningiomas

“…Over the past 2 decades, numerous studies have attempted to predict the consistency of cranial meningiomas by using a variety of advanced MRI techniques, ranging from T2-weighted to diffusion-tensor imaging to MR elastography sequences, mainly with limited success. 1,2,6,7,15 A prior study by Chen et al, from our institution, did show a correlation between soft tumor consistency and hyperintensity on T2-weighted MRI, 2 as have some additional studies. 6,9,12,15,19 Two prior studies have demonstrated an association between hard tumors and the fibroblastic meningioma subtype.…”

“…1,2,6,7,15 A prior study by Chen et al, from our institution, did show a correlation between soft tumor consistency and hyperintensity on T2-weighted MRI, 2 as have some additional studies. 6,9,12,15,19 Two prior studies have demonstrated an association between hard tumors and the fibroblastic meningioma subtype. 1,7 Other studies, however, have found no relationship between imaging findings and consistency 17 or between histology and consistency.…”

Defining the “edge of the envelope”: patient selection in treating complex sellar-based neoplasms via transsphenoidal versus open craniotomy

“…26 Although some authors have reported limited success in the ability to predict tumor consistency based on advanced preoperative imaging modalities, such as T2-weighted MR imaging, diffusion weighted MR imaging, and diffusion tensor MR imaging, the reliability of these techniques is not such that they are widely used to provide this critical information. 4,11,14,30,32,59,62 Promising modalities for predicting tumor consistency include MR imaging or ultrasound elastography. 44,60,61 In the future, a priori knowledge of tumor consistency may lend major support to the selection of a skull base approach from above versus below and warrants further research.…”

Pre-operative Evaluation of Consistency in Intra-axial Brain Tumor with Diffusion-weighted Images (DWI) and Conventional MR Images

“…Several earlier studies assessed the ability of conventional MR imaging for determining the consistency of pituitary adenomas (1)(2)(3)(4)(5)(6) or meningiomas (7)(8)(9)(10)(11). Only a few studies evaluated the consistency of pituitary macroadenomas using apparent diffusion coefficient (ADC) with diffusion weighted imaging (DWI) (12)(13)(14).…”