Snake-Eyes Appearance on MRI Occurs during the Late Stage of Hirayama Disease and Indicates Poor Prognosis

Table 1

Types of classifications of T2-weighted increased signal intensity on MR images.

Type of classification (Basis of classification)	Grade	Description
Longitudinal extent of ISI (One or more segments)	0	No ISI
	1	Focal/single segment ISI
	2	Multisegmental ISI
Qualitative (ISI intensity and border)	0	No change
	1	Faint, fuzzy border
	2	Intense, well-defined border
ISI: Increased signal intensity