Differentiation of glioblastoma multiforme from metastatic brain tumor using proton magnetic resonance spectroscopy, diffusion and perfusion metrics at 3 T

Abstract

Purpose: To assess the contribution of 1H-magnetic resonance spectroscopy (1H-MRS), diffusion-weighted imaging (DWI), diffusion tensor imaging (DTI) and dynamic susceptibility contrast-enhanced (DSCE) imaging metrics in the differentiation of glioblastomas from solitary metastasis, and particularly to clarify the controversial reports regarding the hypothesis that there should be a significant differentiation between the intratumoral and peritumoral areas. Methods: Conventional MR imaging, 1H-MRS, DWI, DTI and DSCE MRI was performed on 49 patients (35 glioblastomas multiforme, 14 metastases) using a 3.0-T MR unit. Metabolite ratios, apparent diffusion coefficient (ADC), fractional anisotropy (FA) and relative cerebral blood volume (rCBV) were measured in the intratumoral and peritumoral regions of the lesions. Receiver-operating characteristic analysis was used to obtain the cut-off values for the parameters presenting a statistical difference between the two tumor groups. Furthermore, we investigated the potential effect of the region of interest (ROI) size on the quantification of diffusion properties in the intratumoral region of the lesions, by applying two different ROI methods. Results: Peritumoral N-acetylaspartate (NAA)/creatine (Cr), choline (Cho)/Cr, Cho/NAA and rCBV significantly differentiated glioblastomas from intracranial metastases. ADC and FA presented no significant difference between the two tumor groups. Conclusions: 1H-MRS and dynamic susceptibility measurements in the peritumoral regions may definitely aid in the differentiation of glioblastomas and solitary metastases. The quantification of the diffusion properties in the intratumoral region is independent of the ROI size placed.

Differences In High-Intensity Signal Volume Between Arterial Spin Labeling And Contrast-Enhanced T1-Weighted Imaging May Be Useful For Differentiating Glioblastoma From Brain Metastasis

“…It is found that a higher degree of surrounding edema was more likely in metastasis, while GBM produced greater contrast enhancement. Cerebral edema in patients with metastatic neoplasms is often vasogenic due to vascular permeability, whereas GBM often exhibits a combination of cytotoxic edema and cell infiltration (4,5,14). Due to these differences in angiogenesis, we suspect that a difference in ASL signal stemming from the tumor Fig.…”

“…Studies using dynamic susceptibility contrast-enhanced (DSC) MRI, the most prevalent perfusion technique, reported a relatively higher value for GBM compared with metastasis. This difference stems from the peritumoral perfusion deficit caused by edema surrounding metastatic tumors (3)(4)(5). However, the presence of tumoral edema and the difference in perfusion are still insufficient for differentiation due to a high likelihood of elevated perfusion value in metastasis (6) and tumoral edema in primary gliomas (7).…”

“…GBM is a highly vascular tumor, and microvessels always infiltrate into surrounding brain tissue (4,5,14). In contrast, there is a lack of angiogenic infiltration into peritumoral tissue in metastasis (15).…”

Clinics in diagnostic imaging (175)

“…Tsougos et al described applications of advanced MR sequences such as MR spectroscopy and MR perfusion in differentiating these two lesions. (8) They described peritumoral ratio as the ratio of a particular parameter in the peritumoral area to that of the contralateral normal area. The authors concluded that elevated peritumoral ratio of rCBV in perfusion imaging, and elevated peritumoral ratios of N-acetylaspartate (NAA)/creatine (Cr), choline (Cho)/Cr, and Cho/NAA ratios in MR spectroscopy are useful imaging findings in differentiating GBM from metastases.…”

Clinical Applications of Synthetic MRI of the Brain

“…[71] The peritumoral oedema is therefore an area which is being thoroughly investigated with different techniques for a better assessment of tumour infiltration, including, e.g., diffusion [64,72,73], perfusion [74], and relaxometry. [75] MR perfusion of the peritumoral area of malignant gliomas shows an increase in relative cerebral blood volume (rCBV) compared to metastases [76] due to the pathological neoangiogenesis induced by the glioma. The perfusion properties of the non-enhancing part of the tumour have also been shown to provide prognostic information, with a high rCBV predicting a worse outcome.…”