Fig. 6.

Case 7. (A) T1-weighted images after administration of gadolinium show the convexity meningioma of the right frontal region. (B) On DWIs, the convexity meningioma is depicted as hyperintensity (white arrows), while cortical hyperintensity is not evident. (C,D) On ASL with both PLD settings, the meningioma is demonstrated as a hypersignal area in nearly the same configuration. On ASL with a PLD of 1.5 s, increased signals are noted at the right frontal convexity, just ventral to the tumor (C, black arrows), which is washed out on ASL with a PLD of 2.5 s. (E) The subtraction image (the data of the ASL with a PLD of 1.5 s was subtracted from the data of ASL with a PLD of 2.5 s) allows ASL signals in the same configuration on the dual PLD setting to be eliminated. Increased ASL signals were noted at the bilateral frontal interhemispheric surfaces and left frontal convexity, in addition to the right frontal convexity, just ventral to the tumor (white arrows).