Value of 4D CT Angiography Combined with Whole Brain CT Perfusion Imaging Feature Analysis under Deep Learning in Imaging Examination of Acute Ischemic Stroke

Table 1

CTP findings before cerebral infarction.

Stage	CTP manifestations	Microcirculation state	Cerebral blood flow status
I1	All parameters were normal	Well-established local collateral circulation in the brain	No drop in CBF
I2	Prolonged TTP and normal MTTCBF and CBV	Uncompensated dilation of microvessels in the brain	CBF above electrical failure threshold
I3	Prolonged TTP and MTT, normal/slightly decreased CBF, and elevated CBV	Compensatory dilation of microvessels in the brain	CBF above electrical failure threshold
II1	Prolonged TTP and MTT, decreased CBF, and normal/slightly decreased CBV	Mild stenosis of local microvascular compression in the brain	CBF between electrical failure threshold and membrane failure
II2	Prolonged TTP and MTT and decreased CBF and CBV	The microvessels in the brain were obviously compressed and narrowed	CBF between electrical failure threshold and membrane failure