[How can metastatic extension be assessed in the brain?].

MRI is the technique of choice to detect cerebral metastases. Double-dose delayed CT is the optimal CT examination to be performed in case of limited access to MRI. If the examination shows the presence of multiple metastases, MRI is not necessary. If CT shows an apparently single lesion, an MRI examination is essential, considering the number of lesions detected by MRI and not seen with CT.