With a view to weighing the clinical significance of asymptomatic cerebral infarction, we analyzed the usefulness of the fluid attenuated inversion recovery method in magnetic resonance imaging. The subjects wee composed of 94 outpatients who participated in our screening program for brain troubles. Indications of asymptomatic cerebral infarction were registered on T2-weighted images of 21 subjects (22%) and on FLAIR images of 31 subjects (33%). The FLAIR method, in which the signals from the cerebrospinal fluid are checked, excelled at detecting lesions, especially those under the cerebral cortex which are almost indistinguishable from gray matter and sulci. The subjects with asymptomatic cerebral infarction had significantly many risk factors for stroke including hypertension and hyperlipidemia. Thus, we concluded that the FLAIR method is very useful in diagnosing asymptomatic cerebral infarction.

Many reports say that DWI (diffusion-weighted-image) is very useful for the diagnosis of cerebral infarction, especially in the acute phase, but it is difficult to have a fine image because DWI is very sensitive to artifacts caused by the “body-move” of the patient.
About the degree of MPG (motion probing gradient), criteria are yet to be established. Many persons try in their own way. With MPG5, the intensity of CSF and that of the focal lesion are almost equal, so that it is difficult to distinguish infarcts from adjacent ventricles.
The stronger the degree of MPG is, the more artifacts or noises we get, We recommend MPG6 or 7 in the right-left direction.