Table 1.

Criteria for groupings based on morphological features visible in tractography. Circumferential alignment was determined by red-green tracts

	Criteria 1	Criteria 2	Criteria 3
Group 1	Circumferential tracts along entire gauge length on medial side
Group 2	Circumferential tracts along entire gauge length on medial side	Circumferential alignment at one end of gauge length on luminal side
Group 3	Circumferential tracts along entire gauge length on medial side	Thick region of plaque in middle of gauge length on luminal side	Mixed alignment covering thick region
Group 4	No clear orientation along entire gauge length, luminal or medial side