Focal Lesion in the Splenium of the Corpus Callosum on FLAIR MR Images: A Common Finding with Aging and after Brain Radiation Therapy
Joseph S. Pekalaa,
Alexander C. Mamouriana,
Heather A. Wishartb,
William F. Hickeyc and
James D. Raqued
a Department of Radiology, Dartmouth-Hitchcock Medical Center, Lebanon, NH
b Department of Psychiatry, Dartmouth-Hitchcock Medical Center, Lebanon, NH
c Department of Pathology, Dartmouth-Hitchcock Medical Center, Lebanon, NH
d Department of Radiology, Finley Hospital, Dubuque, IA

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FIG 1. Case of a 67-year-old patient imaged to rule out aneurysm.
A, Axial and B, sagittal FLAIR MR images (10,000/156/1) show high signal intensity in the anterior subependymal region of the splenium of the corpus callosum, involving more than half the thickness (grade 2).
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FIG 2. Case of a 32-year-old man (patient 12 in Table) with geminocystic astrocytoma.
A, Axial FLAIR MR image (10,002/166/1) obtained 0.8 months before radiation therapy shows normal signal intensity in the splenium.
B, Axial and C, sagittal FLAIR images (10,002/166/1) obtained 5.8 months after radiation therapy demonstrate a bright focus of abnormal signal intensity in the anterior subependymal region of the splenium of the corpus callosum (grade 2).
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FIG 3. Two autopsy cases.
A, Axial FLAIR (10,000/156/1) image obtained in a 63-year-old man shows grade 1 signal intensity abnormality in the anterior subependymal region of the splenium.
B, Photomicrograph of histologic specimen of the splenium (same patient as in A) demonstrates a band of isomorphic gliosis (hematoxylin and eosin stain; original magnification, x60).
C, Axial FLAIR (10,000/156/1) image obtained in an 80-year-old man shows grade 1 signal intensity abnormality in the anterior subependymal region of the splenium.
D, Photomicrograph of histologic specimen of the splenium (same patient as in C) shows no gliosis (hematoxylin and eosin stain; original magnification, x60).
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