Cerebral microbleed (CMB) refers to small, round dark-signal lesions detected by T2*-weighted or gradient-echo (GRE) magnetic resonance imaging (MRI) ..CMBs were introduced to stroke physicians in the late 1990s and early 2000s after development of MRI techniques sensitive to paramagnetic effects The clinical significance of CMBs has been actively investigated, especially in the stroke field and more recently in studies on cognitive impairment, vascular dementia and later developement of cerebral hge ..Histological investigation has shown that CMBs are tiny foci containing hemosiderin-laden macrophages and abnormal microvessels . Clinical cases with frank symptoms caused by CMBs are uncommon, Because CMBs are manifestations of focal extravascular leakage of blood components, however, investigators have suggested that accumulation of CMBs reflects a bleeding-prone status in individuals with an elevated risk of cerebral hemorrhage. Clinical studies have found strong associations between CMBs and chronic hypertension and low cholesterol levels and between the proximity and volume of CMBs and those of subsequent intracerebral hemorrhage (ICH) . studies have found that CMBs are linked to subsequent hemorrhagic stroke in stroke survivors,and suggested that CMBs are related to antithrombotic-related hemorrhage.

Cerebral microbleed (CMB) refers to small, round dark-signal lesions detected by T2*-weighted or gradient-echo (GRE) magnetic resonance imaging (MRI). CMBs were introduced to stroke physicians in the late 1990s and early 2000s after development of MRI techniques sensitive to paramagnetic effects The clinical significance of CMBs has been actively investigated, especially in the stroke field and more recently in studies on cognitive impairment, vascular dementia and later developement of cerebral hge ..Histological investigation has shown that CMBs are tiny foci containing hemosiderin-laden macrophages and abnormal microvessels .

Clinical cases with frank symptoms caused by CMBs are uncommon, Because CMBs are manifestations of focal extravascular leakage of blood components, however, investigators have suggested that accumulation of CMBs reflects a bleeding-prone status in individuals with an elevated risk of cerebral hemorrhage. Clinical studies have found strong associations between CMBs and chronic hypertension and low cholesterol levels and between the proximity and volume of CMBs and those of subsequent intracerebral hemorrhage (ICH) . studies have found that CMBs are linked to subsequent hemorrhagic stroke in stroke survivors,and suggested that CMBs are related to antithrombotic-related hemorrhage.

Clinical implications of cerebral microbleeds The increased of cerebral hemorrhage associated with the presence of CMBs may allow prediction of hemorrhagic transformation after ischemic stroke. An earlier report suggested that hemorrhagic transformation after thrombolysis was associated with the presence of CMBs.

Considerable interest also exists in utilizing detection of CMBs to estimate the risks of hemorrhagic complications in patients on antithrombotic treatment. , CMBs were found to be more frequent and extensive in patients with double antiplatelets-associated ICH.

Inclusion Criteria:

• Patients diagnosed as ischemic CVS or Transient ischemic attack admitted to Assuit University Hospital or visiting outpatient clinic.
• Old stroke patients on double antiplatelet therapy for duration more than 3 months
• old stroke patients on anticoagulants.

Exclusion Criteria:

• Patients with blood diseases hepatic and renal patient. Patients with cerebral hemorrhage.

patients fulfilling previous criteria will undergo T2*-weighted or gradient-echo (GRE) magnetic resonance imaging (MRI) for detection of microbleeds,