Magnetic resonance imaging of intramedullary spinal cord metastasis of cholangiocarcinoma. (a) Magnetic resonance imaging of the cervical spine with T2 short-tau inversion recovery sequences show intramedullary metastases of cholangiocarcinoma at the C4 level. The hyperintensity extended in the spinal cord cranially and caudally relative to the lesion, corresponding to perilesional edema (arrow). (b) Magnetic resonance imaging T1 sequences of the cervical spinal cord acquired at the same level as in (a). Images show contrast enhancement around the medullary lesion, which was moderately intense in the central region and at the periphery (arrow). (c) Three months after radiotherapy, magnetic resonance imaging T1 sequences show that the intramedullary spinal metastasis had regressed markedly.