ANATOMY
EXTRACRANIAL HEAD AND NECK
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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8-5 MHz curvilinear transducer
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7-4 MHz linear array
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4-1 MHz phased array
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5-3 MHz phased array
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Detailed explanation-1: -Transducers with frequencies of 5 to 7.5 MHz are most commonly used. Initially, the common carotid artery (CCA) is identified at the base of the neck and then traced cephalad to identify the bifurcation and both internal and external carotid arteries (ICA and ECA).
Detailed explanation-2: -Magnetic resonance imaging (MRI) used alone can detect intracranial vertebral artery disease, 41, 42 but it is best used in combination with magnetic resonance angiography (MRA) to assess both extra and intracranial vertebral arteries.
Detailed explanation-3: -To obtain a proper color Doppler image, an adequate acoustic angle is essential. With a linear probe, to generate a gray-scale image, the sonic beam needs to be perpendicular to the skin. However, to obtain proper velocity information from color Doppler ultrasonography, the Doppler angle should be between 30° and 60°.
Detailed explanation-4: -Extracranial Doppler examinations are measurements of blood flow velocities in the extracranial vessels, and particularly the Common, External, and Internal Carotid arteries, as well as the Subclavian artery. These measurements are key in the diagnosis of cerebral pathology and circulation.