The use of susceptibility-weighted imaging to detect cerebral microbleeds after lacunar infarction

OBJECTIVE: To study the value of susceptibility-weighted imaging (SWI) technology to detect cerebral microbleeds (CMBs) in senile cerebral lacunar infarction patients; and to evaluate the complicated cerebral hemorrhage risk after patients with CMBs took aspirin, an antiplatelet medication or received anticoagulant therapy. PATIENTS AND METHODS: MRI scanning, using GRE-T2*WI, SWI and FSE sequences (T1WI, T2WI, and T2FLAIR), was performed on the three groups: (1) a cerebral lacunar infarction group; (2) cerebral lacunar infarction with cerebral microbleeds (CMBs) group; and (3) a healthy elderly group. A total of 60 cases were in each group (180 total patients). In addition, the lacunar infarction group and lacunar infarction with CMBs groups were both treated with formal antiplatelet or anticoagulant therapy, according to medical guidelines. Patients were followed for 12 months, during which time their cerebral hemorrhages and post-event effects were observed. The relativity of CMBs, antiplatelet therapy, anticoagulant therapy and cerebral hemorrhage transformation was analyzed and defined. The two groups of research patients with lacunar infarctions were scanned with relevant sequences. RESULTS: The SWI scanning sequence showed the highest positive rate of CMBs, followed by GRE-T2*WI and other conventional scanning sequences. T1WI, T2WI and T2FLAIR showed a relatively lower positive rate of CMBs. In the cerebral lacunar infarction group and healthy elderly group, 34 cases in the SWI sequence showed 84 positive sites; 18 cases in the GRE-T2*WI sequence showed 40 positive sites; 2 cases in the T1WI sequence showed 4 positive sites; and 6 cases in the T2WI sequence showed 11 positive sites. After a chi-squared test, the differences between the sequences were statistically significant (p < 0.05). In the lacunar infarction group, 26 cases (43.33%) exhibited microbleeding lesions, while the normal control group represented 8 cases (13.33%). The lacunar infarction group exhibited mild, moderate and severe cases, the three types of CMBs. The normal control group only showed mild hemorrhaging. The degree of lacunar infarction was significantly related to the severity of CMBs (p < 0.05). After patients with CMBs had received formal antiplatelet therapy and anticoagulation therapy, one case in the lacunar infarction with microbleeds group showed cerebral hemorrhaging, but this had no statistical significance (p > 0.05). CONCLUSIONS: The SWI scanning sequence is more sensitive than the GRE-T2*WI sequence. The GRE-T2*WI sequence is more sensitive than the conventional FSE sequence. SWI is highly sensitive and specific to the diagnosis of CMBs. It is an accurate and effective method for the analysis and diagnosis of CMBs. If patients with CMBs caused by lacunar infarction are treated with antiplatelet and anticoagulant therapy, the risk of cerebral hemorrhagic transformation is relatively smaller within 12 months. However, this needs to be observed further to define possible long-term risks.