Imaging Evaluation Of Susceptibility Weighted Imaging In Abnormal Arteries And Veins In Acute Cerebral Infarction

Objective: To research intracranial artery, arterial thrombosis and abnormal vein on SWI sequence in ischemic cerebral stroke occurd in middle cerebral artery blood supply area. To discuss the relationship among arterial thrombus, abnormal venous and infarction area, degree and position of stenosis vascular, clinical scores and recent prognosis, evaluation the application value on SWI in acute cerebral infarction. Materials and methods: Thirty-two cases which occurred within 24 hours of acute cerebral infarction were included in this study. All patients underwent MR imaging using Siemens Trio 3.0T magnetic resonance imaging system with the following sequence: conventional MRI(T1WI, T2 WI, DWI, FLAIR), MRA, SWI and PWI, and randomly selected 12 patients to review again after thrombolytic therapy in 1 week. In addition to receive 10 cases of normal volunteers as contral group underwent conventional MRI, MRA and SWI. Defined arterial thrombosis showed on SWI as susceptibility vessel sign(SVS).Thirty-two cases of patients with acute infarction were observed intracranial main artery on the SWI sequence, observed SVS display and the distribution and degree of abnormal vein internal and surrounding the infarcts on SWI-mIP. To contral normal volunteers main cerebral artery on SWI, FLAIR and MRA, and assess the differences in SWI and FLAIR sequence with display stenosis or occlusion in intracranial major artery. To calculated the relationship among SVS and infarction area, degree and position of responsibility stenosis vascular, clinical scores and recent prognosis using the statistics respectively, and calculated the relationship among abnormal venous degree and infarction area, degree and position of responsibility stenosis vascular, clinical scores and recent prognosis respectively.To assess the relationship between thrombus length and infarction area, NIHSS scores, the recent prognosis. To observe and evaluate the change of the thrombosis of 12 patients with follow-up after intravenous thrombolysis treatment. To assess the relationship between abnormal venous and the blood perfusion situation in acute cerebral infarction. Result: The lesions of acute cerebral infarction in 32 cases showed high signal on DWI, there were 15 cases with small area, 6 cases with moderate area and 11 cases with large infarctions area. MRA showed one side of the middle cerebral artery occlusion in 19 cases, severe middle cerebral artery stenosis in 3 cases and mild stenosis in 4 cases, 6 cases of MRA were normal. 28 cases had abnormal perfusion. The range of abnormal perfusion in 26 cases were bigger than DWI. Sixteen cases showed SVS sign, consisted with the lesions region of MRA. The positive rate of SVS was 50%(16/32), mainly occured in the middle cerebral artery segment level, accounted for 50%(8/16), and one case occurred in the distal branch of middle cerebral artery. There was no SVS sign on the non-responsibility stenosis artery. The display of intracranial main artery between SWI and TOF-MRA original image had no obvious difference in 10 cases of normal volunteers. The expression of lesions vascular in acute cerebral infarcts on SWI was more sensitive than FLAIR sequence.(the sensitivity of SWI was 100%, and the FLAIR was 81.8%). The acute infarction area with SVS positive was greater than the negative, there had statistically difference(P<0.05). SVS displayed on SWI was associated with the degree of artery stenosis, NIHSS scores, recent prognosis(P<0.05).The relationship between thrombus length and the infarction area, NIHSS score and recent prognosis were not statistically significant(P>0.05). Randomly selected 12 patients after thrombolysis treatment to review MRI examination. Two cases with SVS were disappeared, 1 case with SVS was smaller, 1 case with SVS was change the position in 5 cases with SVS positive in the first examination. And these cases were appeard recanalization of middle cerebral artery in varying degrees on MRA. One case SVS was larger. 1 case with SVS smaller and 1 case with SVS disappeared both happend hemorrhagic in these 5 patients.The vein in the acute infarcts area was reduced or disappeard on SWI in 32 cases. SWI demonstrated significant increase of cerebral vein distribution around the acute infarcts area in 19 cases and slight increase in 10 cases. Three cases of vein were not obvious changed. The range of abnormal cerebral vein distribution were generally consistent of the range of abnormal perfusion on MTT in 26 cases. There were not seen abnormal venous distribution around the chronic infarcts in the other side. The degree of abnormal vein distribution aroud infarcts area was associated with the acute infarcts area, the degree of artery stenosis, NIHSS scores, recent prognosis(P<0.05). The degree of abnormal vein distribution aroud infarcts area had relationship with the the state of the blood perfusion(P<0.05). The correlation between the degree of abnormal vein and arterial lesion location had no statistical significance(P>0.05). Conclusion:1. SWI can show the main artery of intracranial and sensitive to detect arterial thrombus in acute cerebral infarction, having good consistency results with MRA. SVS positive prompts large infarction area, heavy degree of vascular stenosis, severe neurologic deficits and poor recent prognosis. Assessing the thrombus with SWI helps speculate the evolution and outcome of thrombus after treatment, provide reference for the choice of clinical treatment.2. SWI-mIP chart can display abnormal distribution of the vein around the acute infarcts. Vein increasing significantly prompts large infarction area, heavy degree of vascular stenosis, severe neurologic deficits and poor recent prognosis. Displaying of veins around the infarcts with SWI-mIP reflects the state of the blood perfusion of ischemic brain tissue and cell metabolic state, assesses brain vitality, helps clinical evaluation of acute cerebral infarction patients to choose the appropriate treatment.3. SWI sequence can assess artery and vein of patients with acute cerebral infarction, provide important reference information for clinical to assess patient’s condition and to choose appropriate treatment. SWI can be used as a routine examination sequence of acute cerebral infarction.