Application of 3.0T magnetic resonance arterial spin labeling (ASL) technology in mild and moderate intracranial atherosclerotic stenosis

The application value of 3.0T magnetic resonance arterial spin labeling (ASL) technology in mild and moderate intracranial atherosclerotic stenosis was evaluated. A total of 58 cases of transient ischemic attack (TIA) and 60 cases of ischemic cerebral apoplexy cases were selected. The cases were analysed using a GE Healthcare Signa HDx 3.0T superconducting whole-body magnetic resonance scan within 24 h of attack. Eight-channel head phased array coils and conventional sequence were used to create T1-weighted images (T1WI), T2WI, diffusion-weighted imaging, magnetic resonance angiography (MRA) and ASL imaging, which were generated into ASL pseudo-color images (blue was hypoperfusion area) through post-processing in order to compare and analyze the correlation and differences between ASL and conventional imaging in terms of lesion location, size, blood perfusion situation and signal range of relative cerebral blood flow (rCBF). The results showed that, 13 TIA cases of abnormal signal in conventional magnetic resonance imaging (MRI) can also be found through ASL technology. Diameter stenosis beyond 30% in MRA can also be tested in ASL. A positive rate in ASL was significantly higher than that of conventional MRI (χ2=29.078, P<0.001) and hypoperfusion area was greatly increased (t=32.526, P<0.001). The rCBF value was positively correlated with the degree of diameter stenosis shown in MRA (r=0.524, P=0.012). Additionally, the positive rate of ASL was positively correlated with the attack times of TIA (r=0.352, P=0.027). A total of 39 cerebral apoplexy cases of abnormal signal in conventional MRI were also found through ASL technology. A positive rate in ASL was significantly higher than that of conventional MRI (χ2=7.685, P=0.006) and hypoperfusion area was greatly increased (t=9.425, P<0.001). The rCBF value was positively correlated with the degree of diameter stenosis (r=0.635, P=0.009). In conclusion, 3.0T ASL correlated with early diagnosis of TIA and mild and moderate intracranial arterial stenosis of cerebral apoplexy.