Objective To evaluate the perfusion findings of solitary brain metastasis using MR arterial spin labeling (ASL)imaging,and make a comparison with dynamic susceptibility contrast (DSC)imaging.Methods Twenty-three patients with pathologically proven solitary brain metastasis from lung cancer underwent ASL and DSC imaging.The ASL cerebral blood flow (CBF),DSC regional CBF (rCBF)and DSC regional cerebral blood volume (rCBV)were measured and compared between the tumor and the contralateral brain parenchyma.Pearson correlation test was performed to assess the relations between ASL and DSC measurements.Results Brain metastasis showed ring-like hyper-perfusion on ASL and DSC mappings.ASL CBF values of the tumor and the contralateral brain parenchyma were(54.872±21.131)mL·min-1·100 g-1and (21.109±4.788)mL·min-1·100 g-1,respectively (P<0.01).DSC rCBF values of the tumor and the contralateral brain parenchyma were (1.094 8±0.309 3)mL·min-1·100 g-1and (0.495 7±0.154 1)mL· min-1·100 g-1,respectively (P<0.01).DSC rCBV values of the tumor and the contralateral brain parenchyma were (1.753 1±0.545 5)mL/100 g and (0.729 9±0.215 8)mL/100 g,respectively (P<0.01).There was a strong correlation between ASL CBF and DSC rCBF (r=0.898,P<0.01),and there was no correlation between ASL CBF and DSC rCBV.Conclusion ASL can evaluate the CBF of brain metastasis as DSC dose. It requires no contrast agent administration and can be used in daily clinical practice.