Aement of Axonal Degeneration Along the Human Viual Pathway Uing Diffuion Trace Analyi Original Reearch Article

Purpoe The effectivene of diffuion trace value analyi for non-invaive aement of retinal ganglion cell (RGC) axonal degeneration at multiple anatomic level along the human viual pathway under clinical etting wa evaluated. Deign Imaging tudy. Method Ten patient with unilateral chronic optic neuropathy of varying caue and 16 age-matched normal ubject were tudied. Trace, a tenor invariant that i conidered to be a enitive index for pathologic change in axon, wa analyzed at nine anatomic ite in each ubject, namely, bilaterally at the level of the optic nerve, uncroed chiamal fiber, optic tract and optic radiation, and croed chiamal fiber, uing a 3.0 Tela magnetic reonance imaging ytem. Reult Trace value of the optic nerve and uncroed chiamal fiber ipilateral to the affected eye, the croed chiamal fiber, and optic tract bilaterally were ignificantly higher than thoe of the correponding anatomic ite in normal ubject. The optic nerve and uncroed chiamal fiber ipilateral to the unaffected ide and optic radiation, bilaterally, had trace value which were not ignificantly different from the value of the correponding anatomic level in normal ubject. The increae in trace value in the optic nerve and uncroed chiamal fiber ipilateral to the affected ide wa greater than thoe of the croed chiamal fiber and optic tract. Concluion Finding are highly conitent with a degenerative proce of RGC axon and trace value are quantitatively well correlated to predicted pathology at the given anatomical ite. Trace value meaurement at multiple ite along fiber pathway appear to be a powerful addition to clinical aement of the functionality of component of the viual pathway during variou tage of a pathologic proce.