Usefulness of quantitative peritumoural perfusion and proton spectroscopic magnetic resonance imaging evaluation in differentiating brain gliomas from solitary brain metastases

Abstract

Objectives: The purpose of our study was to evaluate whether peritumoural perfusion weighted and proton spectroscopic magnetic resonance imaging can be used in differentiating between primary gliomas and solitary metastases.

Methods: Ten low-grade gliomas, eight high-grade gliomas and 10 metastases were prospectively evaluated with magnetic resonance imaging, dynamic susceptibility contrast enhanced perfusion imaging and single-voxel proton magnetic resonance spectroscopy before surgical resection or stereotactic biopsy. Maximal relative cerebral blood volume values were calculated drawing three regions of interest of 2 cm(2) in the non-enhancing peritumoural areas. Maximal relative cerebral blood volume values were normalised to that of contralateral normal-appearing white matter. Maximal choline/creatine ratios were calculated from three voxels of 10 cm(3) placed in the peritumoural areas defined as non-enhancing peritumoural white matter surrounding the tumour. The tumour grade presumed with these values was compared to histopathological grading. Differences in the study parameters between groups were assessed using the Mann-Whitney test. A receiver operating characteristic analysis was performed to determine cut-off values.

Results: A clear relative cerebral blood volume cut-off value of 1.88 was detected for differentiating low-grade gliomas from high-grade gliomas. A clear relative cerebral blood volume cut-off value of 1.20 was detected for differentiation of metastases from gliomas. The differences in the choline/creatine ratios in the peritumoural regions of high-grade gliomas and of solitary metastasis were statistically significant (P < 0.001) but a clear cut-off value was not found.

Conclusion: Our preliminary data support the hypothesis that peritumoural perfusion-weighted imaging can assist in preoperative differentiation between a glioma and a solitary metastasis.

Keywords: Brain glioma; brain metastases; magnetic resonance spectroscopy; perfusion weighted magnetic resonance imaging.

Figure 1.

A 44-year-old woman with a pathologically proved glioblastoma. (a) Contrast-enhanced axial T1-weighted image (600/14) demonstrating a peripherally enhancing lesion in the left parietal lobe. (b) Cerebral blood volume map with regions of interest of 2 cm² drawn in the peritumoural white matter of the left parietal lobe and in the contralateral normal-appearing white matter.

Figure 2.

(a) Scatterplot demonstrating a relative cerebral blood volume (rCBV) cut-off value of 1.20 to differentiate between a metastasis (MTS) and a glioma. (b) Receiver operating characteristic curve demonstrating 100% sensitivity and 90% specificity of rCBV cut-off value of 1.20 to differentiate between a metastasis and a glioma. AUC: area under the curve; NAWM: normal-appearing white matter.

Figure 3.

(a) Scatterplot demonstrating the relative cerebral blood volume (rCBV) cut-off value of 1.88 to differentiate between high-grade gliomas and low-grade gliomas. (b) Receiver operating characteristic curve demonstrating 100% sensitivity and 90% specificity of rCBV cut-off value of 1.88 for differentiating between high-grade gliomas and low-grade gliomas. AUC: area under the curve; NAWM: normal-appearing white matter.