Measurement of the diameter of the MMA branch origin from the trunk. DSA showed the MMA and its branches. For the case of a DAVF with the PSB and PB acting as the main feeding arteries, the PSB (arrow) was chosen as the arterial path to perform EVT, and the diameter of the PSB origin from the trunk was measured (red line segment). DSA, digital subtraction angiography; EVT, endovascular treatment; MMA, middle meningeal artery; PB, petrous branch; PSB, petrosquamosal branch.