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Atlas of Human Body Ultrasound Scanning_ Methods and Diagnostic Applications ( PDFDrive ).pdf
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7  Vascular System Scanning

125

 

 

1.3\ Pulsed-Doppler Spectrum

of the Common Carotid Artery

Fig. 7.3  Doppler spectrum of the common carotid artery

1.3.1\ Scanning Method

The subject takes a supine position with the head slightly stretched to make a full extension of the neck. The head holds the middle position or turns to the opposite side when one side of the common carotid artery is examined. The probe is put on the lateral or post-lateral neck, and a longitudinal scanning is performed from bottom to top.

1.3.2\ Sectional Structure

Showing the longitudinal section and the blood flow spectrum of the common carotid artery.

1.3.3\ Measurement Methods

and Normal Value

Under the guidance of color Doppler, the Pulsed-­ Doppler sampling volume is placed in the middle of the common carotid artery; the distance between the sampling volume and the carotid artery bifurcation should be longer than 2 cm. If there is stenosis in the carotid artery, the distance between the sampling volume and the carotid

artery bifurcation should be longer than 4 cm or placed in the middle of the lumen of the brightest point of the color blood flow. The closer to the bifurcation, the lower the flow velocity is. Doppler beam correcting the angle θ line should be parallel to the beam flow line; the angle should be less than or equal to 60°.The value of peak blood flow velocity is shown in Table 7.2.

1.3.4\ Clinical Significance

Normally the spectrum shape in the middle of the bilateral carotid artery should be in symmetry. If there is a stenosis in the ipsilateral, contralateral, and proximal common carotid artery, the distal internal carotid artery and the common carotid artery blood flow spectrum will have a high resistance state. If there is a communicating branch in the intracranial vessel, a lower resistance state may appear. The peak blood flow velocity will decrease with the increase of age.

126

B. Su and Q. Yong

 

 

1.4\ Longitudinal Scanning n

of the Internal and External

Carotid Artery

Fig. 7.4  Longitudinal section of the internal and external carotid artery

CCA

ICA

ECA

7  Vascular System Scanning

127

 

 

1.4.1\ Scanning Method

The subject takes a supine position with the head slightly stretched to make a full extension of the neck. The probe is placed on the posterolateral neck behind the sternocleidomastoid and the sound beam directly from the anteromedial to the sternocleidomastoid muscle, showing the longitudinal section of the bifurcation of the common carotid artery. The internal carotid artery is located at the posteroexternal neck, and the external carotid artery is located at the anteromedial neck.

1.4.2\ Sectional Structure

Showing the longitudinal section of the common carotid artery and the internal and external carotid artery.

1.4.3\ Measurement Methods

Measuring the intima-media thickness (IMT) and diameter, involving the range of the plaque and blood flow spectrum of the carotid artery.

1.4.4\ Clinical Significance

Showing the anatomic location and the situation of the wall and lumen of the internal and external carotid artery. Measuring the blood flow spectrum of the internal and external carotid artery.

1.4.5\ Note

It is reported that 60% of the internal and external carotid artery can be displayed in the same plane on the level of bifurcation, and only one blood vessel can be displayed on the level of the common carotid artery. In general, the external carotid artery is thin and has branches, and the superior thyroid artery is the first branch of it, which is easy to be observed. The internal carotid artery is usually wide in diameter and does not have branches.

128

1.5\ Transverse Scanning

of the Internal Carotid Artery

and External Carotid Artery

Fig. 7.5  Transverse section of the internal carotid artery and external carotid artery

RIJV

B. Su and Q. Yong

RECA

RICA