| Popis: |
Sonography is recognized as the best screening tool for detecting carotid artery stenosis. Nevertheless, cervical ultrasound examination is subject to practical limitations in some rare circumstances. Transcranial sonography is now included in the evaluation of patients with suspected cerebrovascular disease, but attenuation of the ultrasound signal by the skull is common. Contrast agents are known to amplify the reflection of ultrasonic energy and to improve the signal : noise ratio. They can in most cases compensate for the shortcomings encountered in the ultrasound cerebrovascular examination. They are safe and well tolerated. In difficult situations they allow an accurate grading of carotid stenosis and an improved assessment of the intra-cranial arteries. They also enlarge the role of transcranial Doppler. |
