Magnetic resonance imaging of rare intracranial neoplasms--role of the in vivo 1 h spectroscopy in the radiological differential diagnostics.

Background: The object of this study was to evaluate the usefulness of magnetic resonance (MR) spectroscopy in differentiating rare intracranial tumours in adult patients. Review of the literature on results of MR spectroscopy in these lesions is also included.

Material and method: 89 patients with brain tumours were evaluated preoperatively with in vivo 1.5 T MR spectroscopy (according to eTumour study requirements). 8 of them were diagnosed as having very rare neoplasms: haemangiopericytoma (2), lymphoma (2), plexus papilloma (2), chondroma (1) and purkinjoma (1). Spectra of these tumours were compared to spectra of common brain tumours that could resemble these lesions.

Results: MR spectroscopy enabled discrimination between meningiomas and haemangiopericytomas, meningiomas and lymphomas, and purkinjomas or chondromas and other brain tumours. The method was unreliable in distinguishing between glioblastomas and lymphomas.

Conclusion: The small number of patients made statistical analysis impossible. However, at present, it seems that neuroradiological diagnosis should not rely on MR spectroscopy alone.