Intracranial neoplasms: MR imaging with gadolinium - DOTA

After a review of the capabilities of magnetic resonance without contrast in the diagnostic assessment of intracranial tumors, the authors report the literature and their own experience concerning the use of the paramagnetic contrast agent gadolinium-DOTA in MR imaging. A 0.5 T superconducting system (Toshiba MRT-50A) was used in the evaluation of these tumors. The intravenous administration of gadolinium-DOTA does not substantially increase the sensitivity of MR to primary intra-axial tumors. However, it may provide better delineation of tumor macroscopic extension and separation of the nidus from the surrounding edema. The presence of enhancement reflects areas of alteration of the blood brain barrier and may anticipate malignant changes at the histopathological examination. The role of gadolinium-DOTA administration for differentiation of intra-axial tumor recurrence from parenchyma changes induced by surgery or radiotherapy remains to be established. On the other hand, gadolinium-DOTA dramatically increases the sensitivity and specificity of MR in the investigation of extra-axial primary tumors (meningiomas, neurinomas), sellar tumors and secondary neoplastic lesions as well as in the investigation of their recurrence. Gadolinium-DOTA may be indirectly useful in the identification of the dysontogenetic tumors do not show enhancement as the low grade tumors do. (author)