Spatial orientation of the thalami. Spatial orientation of the thalami. A, Grade 0: Axial T2-weighted image shows the thalami with their long axes at an angle approximately 30° to 45° relative to the plane of the IHF (arrows).B, Grade 1: Axial T2-weighted image shows the thalami with their long axes approximately parallel to the plane of the IHF (arrows).C, Grade 2: Axial T2-weighted image shows the thalami with their long axes approximately perpendicular to the plane of the IHF (arrows). Erin M. Simon et al. AJNR Am J Neuroradiol 2000;21:1955-1961 ©2000 by American Society of Neuroradiology