Multi-modality MRI Study on Effect to Collateral Circulation and Blood Perfusion of Acute Cerebral Infarction by Human Urinary Kallidinogenase

Inclusion Criteria: * Age:greater than or equal to 18 years old and less than or equal to 70 years old; * Time of onset is less than 7 days; * Acute cerebral infarction due to the stenosis or occlusion of middle cerebral artery diagnosed by CT or MRI; * The National Institute of Health Stroke Scale(NIHSS) score is 4 to 20; * Excluding intracranial hemorrhage using CT or MRI. Exclusion Criteria: * The NIHSS score is less than or equal to 3; * Patients with cerebral aneurysm, cerebral hemorrhage, brain tumor, brain contusion and laceration of brain and other diseases; * Intracranial hemorrhage displaying by CT or MRI; Cardiac insufficiency; * Cardiac insufficiency; * Chronic liver disease(A/G inversion),elevated alanine aminotransferase(ALT)(more than 1.5 times the normal value); * Increased serum creatinine(more than 1.5 times the normal value); * Poorly controlled diabetes; * Recently suffered from hemorrhagic disease or bleeding tendency; * Recent use of angiotensin-converting enzyme inhibitor (ACEI) drugs; * Allergic constitution and had a variety of drug allergy history; * Women in period of pregnancy or lactation.