Solitary metastases and high-grade gliomas: radiological differentiation by morphometric analysis and perfusion-weighted MRI

Abstract

To evaluate the value of morphometric analysis and perfusion-weighted magnetic resonance imaging (MRI) in differentiating solitary metastases from high-grade gliomas. Forty-eight tumours (22 high-grade gliomas and 26 solitary hemispheric metastases) were evaluated using conventional and perfusion-weighted MRI. T2-weighted, gradient-echo, echo-planar sequences were used for perfusion-weighted MRI. Relative cerebral blood volume (rCBV) ratios were calculated by dividing the rCBV of the intratumoural and peritumoural areas with the average CBV value of the normal white matter areas. Morphometric analysis was carried out by proportioning the area of peritumoural oedema to the mass area. Mann-Whitney U test and ROC curve analysis were applied for statistical analysis. P<0.05 was accepted as statistically significant. Mean rCBV ratios of intratumoural areas of high-grade gliomas and metastases were 5.02+/-2.47 and 4.62+/-2.46, respectively. No statistically significant difference was found (p=0.515). rCBV ratios of peritumoural oedema were 0.89+/-0.51 in high-grade gliomas and 0.31+/-0.12 in metastases. The difference was statistically significant (p<0.001). According to the results of morphometric analysis, a statistically significant difference was present between the two tumour types (p<0.001). Measuring the oedema: mass and rCBV ratios of the oedema surrounding the tumour prior to operation in solitary masses proved to be useful for differentiating metastases from high-grade gliomas.