Increased blood flow in the middle cerebral artery is common in two ways: first, stenosis, where the narrowing of the vessel results in a smaller lumen, leading to increased blood flow through it. The second aspect, vasospasm, is that the patient has recently experienced spasm of the blood vessels for some reason, and a Doppler check will show increased blood flow in the middle cerebral artery. The most authoritative test to distinguish between stenosis or increased flow velocity in the middle cerebral artery due to vasospasm is CTA or MRA to clarify whether there is local stenosis. If there is no stenosis, the increased blood flow is ruled out as a result of stenosis, and the diagnosis is basically due to vasospasm, and the blood flow is faster due to vasospasm, which can be seen to slow down after a period of time.