Summary of the main perfusion MRI study findings in MS

	Active Lesions	Chronic Lesions	NAWM	Deep Gray Matter
CBF	↑ (Compared with NAWM)	↓ (Compared with NAWM and WM in controls)	↓ (Compared with WM in controls)	↓ (Compared with controls)
CBV	↑ (Compared with NAWM)	↓ (Compared with NAWM)	↓ (Compared with WM in controls)	↓ (Compared with controls)
MTT	No significant change	↑ (Compared with WM in controls)	↑ (Compared with WM in controls)	↑ (Compared with controls)

Note:—↑ indicates increased; ↓, decreased.