Benefits of contrast-enhanced SWI in patients with glioblastoma multiforme.

INTRODUCTION

SWI can help to identify high-grade gliomas (HGG). The objective of this study was to analyse SWI and CE-SWI characteristics, i.e. the relationship between contrast-induced phase shifts (CIPS) and intratumoral susceptibility signals (ITSS) and their association with tumour volume in patients with glioblastoma multiforme (GBM).

MATERIALS AND METHODS

MRI studies of 29 patients were performed to evaluate distinct susceptibility signals comparing SWI and CE-SWI characteristics. The relationship between these susceptibility signals and CE-T1w tumour volume was analysed by using Spearman's rank correlation coefficient and Kruskal-Wallis-test. Tumour biopsies of different susceptibility signals were performed in one patient.

RESULTS

Comparison of SWI and CE-SWI demonstrated different susceptibility signals. Susceptibility signals visible on SWI images are consistent with ITSS; those only seen on CE-SWI were identified as CIPS. Correlation with CE-T1w tumour volume revealed that CIPS were especially present in small or medium-sized GBM (Spearman's rho r = 0.843, P < 0.001). Histology identified the area with CIPS as the tumour invasion zone, while the area with ITSS represented micro-haemorrhage, highly pathological vessels and necrosis.

CONCLUSION

CE-SWI adds information to the evaluation of GBM before therapy. It might have the potential to non-invasively identify the tumour invasion zone as demonstrated by biopsies in one case.

KEY POINTS

• MRI is used to help differentiate between low- and high-grade gliomas. • Contrast-enhanced susceptibility-weighted MRI (CE-SWI) helps to identify patients with glioblastoma multiforme. • CE-SWI delineates the susceptibility signal (CIPS and ITSS) more than the native SWI. • CE-SWI might have the potential to non-invasively identify the tumour invasion zone.