Deqiang Qiu1, Silun Wang1,2,
Kwok-Fai So3, Ed Xuekui Wu4, Lucullus Hing-Tong Leung5,
Pek-Lan Khong1
1Diagnostic Radiology, The University
of Hong Kong, Hong Kong, China; 2Radiology, Johns Hopkins
University, Baltimore, MD, United States; 3Anatomy, The University
of Hong Kong; 4Laboratory of Biomedical Imaging and Signal
Processing, The University of Hong Kong; 5Oncology, Princess
Margaret Hospital, Hong Kong, China
In
the present study, we evaluated changes of multiple white matter tracts following
radiation using diffusion tensor imaging. A novel finding of severe changes
in FA in the contralateral optic nerve as compared to the ipsilateral optic
nerve was observed, and these changes were confirmed by histological
evaluation. These findings cannot be explained by difference in radiation
dose and suggests, for the first time, an important role of retrograde
neuronal degeneration in the underlying mechanism for radiation induced
injury to the visual pathway. The results also suggest susceptibility of the
optic nerve relative to the cerebral peduncle.