Xi YB, et al. - In order to distinguish primary central nervous system lymphoma (PCNSL) from high-grade glioma (HGG) and brain metastasis, researchers assessed the diagnostic ability of arterial spin labeling (ASL) and dynamic contrast-enhanced (DCE)-derived permeability parameters. For this investigation, eight patients with PCNSL, 21 patients with HGG, and six with brain metastasis had preoperative 3.0-T MR imaging including conventional, ASL, and DCE. In comparison with HGG and metastasis, PCNSL showed significantly lower relative cerebral blood flow (rCBF), higher volume transfer constant (K^trans) and extravascular extracellular volume fraction. The diagnostic ability for PCNSL was improved with AUC of 0.986 with the combination of rCBF and Ktrans. Overall, the investigators suggested that rCBF and Ktrans are valuable parameters to distinguish PCNSL from HGG and brain metastasis. The combination of rCBF and Ktrans contributes even more to improving PCNSL diagnostic performance.