Transcranial Doppler monitoring and analysis of large area cerebral infarction, relation result MRI examination, proved to be a large area of cerebral infarction, middle cerebral artery area are. 1.2 methods: the Shenzhen City Kay electronic limited company EMS--9100 transcranial Doppler instrument, 2MFIz pulse probe, through temporal window, pillow window detection, respectively from the anterior cerebral artery (ACA) 60 ~ 64cm, artery (MCA) 50 ~ 58cm, after arterial (PCA) 70 ~ 75cm, vertebral artery (VA) 60 ~ 65cm, basilar artery (BA) 70 ~ 75cm hemodynamic information, recording of blood flow velocity and pulsatility index values, at the same time to observe the morphologic spectrum, listening to audio, analysis. 2 results of 9 cases of early massive infarction, admission CT examination showed no abnormalities, TCD display of middle cerebral artery occlusion in 4 cases. Mainly for the MCA flow signal disappears, ipsilateral ACA flow speed, 3 cases showed contralateral and ipsilateral MCA, ACA ACA flow speed. A branch of the middle cerebral artery occlusion in 5 cases. Manifestations of middle cerebral artery blood flow velocity was significantly slowed down, mean blood flow velocity of 38cm/s. Among the 3 patients in the course of fourth to 5 days due to herniation of brain death. The detection process is not found in establishment of collateral circulation, the resistance index increased gradually. In 5 patients 1 weeks to monitor occlusion recanalization, clinical symptom alleviates gradually, but the complex flow velocity than the ipsilateral ACA. PCA flow rate has no obvious change. Acute large area cerebral infarction in patients with clinical symptoms and very early patients with basically the same (with varying degrees of impaired consciousness, sleepiness, lethargy, shallow to moderate coma, convulsions, some patients with high fever), but TCD not found in MCA trunk occlusion of blood flow change, in which the MCA velocity significantly slowed in 23 patients (mean blood flow velocity of 42cm/s), vascular stenosis in 10 patients (mean flow velocity, 160cm/s), their morphologic spectrum high, audio rough, visible vortex or turbulence, and smell and special whistles, after analysis, article ID 1812 - 786X (2005) 9 - 0089 - 01 by CT and MRI confirmed the middle cerebral artery stenosis. 31 patients had different degree of ipsilateral ACA flow speed, or with contralateral ACA, MCA flow speed. In 2 cases no change in aca. S/D is greater than 3, the morphological spectrum of high point, 5 days later died of cerebral hernia. 3 weeks after the review, artery blood flow changes in good functional recovery, performance for the flow velocity gradually increases quickly, but compared with the contralateral side slowly, the patient. After 3 months, 25 cases of patients with brain, artery blood velocity returned to normal, and contralateral basic symmetry. In 12 cases of blood flow velocity in patients with different degree of faster, but still more contralateral slow. Discussion of monitoring, 3 study shows, TCD of internal carotid artery system in the area of infarction test has high clinical value, its performance for the MCA blood flow spectrum and the abnormal rate was 100%. Study finds, acute MCA feeding area infarction more performance for the MCA slow blood flow, often accompanied by ipsilateral ACA flow speed, or for lesions in the lateral MCA flow speed. Ultra early cerebral infarction patients, MCA flow signal disappeared in 4 cases, MCA slow blood flow in 5 cases, acute large area cerebral infarction symptom severity in patients with very early, but TCD not found in MCA trunk vascular occlusion, only the performance for slow blood flow, vascular stenosis and other changes, may exceed early in patients with abnormal TCD the high rate of MCA trunk occlusion, collateral circulation is not yet established, vascular recanalization in acute cerebral vascular regulation, and perfect gradually, then to establish effective collateral circulation. 3 cases of early large infarction and 2 patients in the acute phase of large infarction death in patients with TCD, PCA, detection of ACA was no compensatory increase quickly, died of cerebral hernia. Therefore, we believe that the ACA, increased blood flow, not only can be used as MCA occlusion of the aided diagnosis index, also can be used to evaluate the ACA to the MCA function of coronary collateral circulation and effective degree, at the same time, TCD for such patients prognosis will be of great help. Acute massive cerebral infarction patients whether in short-term inside establish effective collateral circulation, has the vital significance in prognosis. Cranial CT, MRI applications for cerebral infarction location, qualitative diagnosis provides exact basis, but in early cerebral infarction, intracranial artery structure did not change significantly, its positive rate is low, we applied the TCD technology, you can dynamically observe the intracranial artery blood flow state of motion, and on the basis of understanding, stenosis, cerebral vascular spasm occlusion and cutting a compensatory circulation situation, provide an objective basis for clinical treatment. This study confirmed, TCD on acute large area cerebral infarction in patients with intracranial blood flow changes found early, high sensitivity, can be associated with CT, MRI complementary.