Background: Irradiation to the central nervous system (CNS) in childhood is known to induce cerebral calcification after a latent period. Calcification has been generally found to show nil or a reduction in signal intensity in magnetic resonance (MR) images. However, we have studied three patients with radiation-induced brain calcification, who manifested increased signal intensity on T1-weighted MR images.
Method: Three girls had each been diagnosed as having a suprasellar germ cell tumour and were treated with conventional fractionated radiotherapy in their childhood. In one case, chemotherapy was given prior to the CNS irradiation.
Findings: All three patients survived their disease, and a follow-up CT scan revealed calcification in the brain, which has shown an increased signal intensity in the T1-weighted images of MR.
Interpretation: Cerebral calcification may be presented as a high signal intensity in the T1-weighted MR images. This may be explained by a surface-relaxation effect by the calcium salt particle, precipitated in the brain due to radiation-induced mineralising microangiopathy.