Monitoring of Frequency Spectra in the MCA During Angiography
To determine the effect of contrast medium injected during angiographic examinations on the blood flow velocity in the middle cerebral artery, velocities in the MCA were recorded transcranially while contrast agent was being applied. Shortly after 10 ml contrast medium was injected into the cervical carotid artery, a loud noise could be heard in the Doppler sonographic recording, which lasted for 10 seconds. After the autotransfusion of 10 ml blood, the same phenomenon occurred, however, for only 6 seconds (Fig. 100).
KeywordsContrast Agent Contrast Medium Middle Cerebral Artery Frequency Spectrum Blood Flow Velocity
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