Abstract
The major objectives of neuroradiological diagnosis of the patients with aphasia can be summarized as follows; 1) to clarify the classical lesions producing aphasia, 2) to reveal the underlying disease and its pathophysiology, 3) to identify the lesion producing non-aphasic speech disturbance. Brain imaging is useful in diagnosing such as cerebral vascular diseases and senile dementia producing aphasia. Computed tomography and MRI are designed to identify the organic lesions, while positron CT and SPECT are used to investigate functional disorders of the brain. In the diagnosis of cerebral vacular diseases, it is necessary to distinguish between a brain infarction and a brain hemorrhage. In the case of a brain infarction, it is necessary to make the diagnosis of thrombosis or emboism. Sometimes, the pathophysiology of the cerebral vascular diseases changes dramatically from the acute to the chronic stage. Paretic dysarthria is an important sign of non-aphasic speech disturbance. The neuroanatomical localization of the pyramidal tract should be understood in the neuroradiological diagnosis of the patient with aphasia.
