Добавил:
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз: Предмет: Файл:
Atlas of Human Body Ultrasound Scanning_ Methods and Diagnostic Applications ( PDFDrive ).pdf
Скачиваний:
177
Добавлен:
29.07.2022
Размер:
40.13 Mб
Скачать

336

Z. Xu et al.

 

 

1\ Artery System

1.1\ Long-Axis Scanning

of the Abdominal Aorta

Ao

Fig. 9.1  Long-axis view of the abdominal aorta

1.1.1\ Scanning Method

The patient should be on an empty stomach for 8–12 h, and should be in a supine position. The probe is placed vertically 1–2 cm to the left of the midsagittal line.

1.1.2\ Section Structure

Long-axis section of the abdominal aorta (Ao); the diameter tapers gradually from the proximal to the distal.

1.1.3\ Measurement Method and Normal Value

The anterior–posterior diameter is measured on the maximum sagittal section, from the outer surface of one side of the artery wall to the other side. The diameter of the lower segment of the Ao is 2.0 ± 0.25 cm in males and 1.7 ± 0.15 cm in females. For measurement of the inner diameter, the cursors are placed at the interface of the lumen and the inner membrane from one side to the other side. Lumen stenosis rate = (inner diameter − minimal inner diameter at stenosis) ÷ inner diameter.

1.1.4\ Clinical Application Value

On this section, the whole Ao is evaluated to exclude a stenosis or dilation of the lumen. An aneurysm can be diagnosed if a lumen dilation above 50% is observed. Regular monitoring of the aneurysm size is preferred. The structure of the Ao should be evaluated on this section; thickening of the artery wall and stenosis of the lumen can be observed in the Ao involving Takayasu arteritis. In arteriosclerosis, asymmetrical thickening and echo change of the inner middle layer is commonly observed.

9  Abdominal Vascular Scanning

 

 

337

 

 

 

1.2\

Lateral Lumbar Scanning:

position. The probe is placed vertically on the

 

Coronal View

 

 

lateral lumbar region. The liver and right kidney

 

of the Abdominal Aorta

 

(spleen and left kidney) can be used as the acous-

 

 

 

 

tic window. Scanning is performed continuously

 

 

 

 

from anterior to posterior. The position of the

 

 

 

 

probe should be adjusted to the real longitudinal

 

 

 

 

section of the lumen if the Ao runs tortuously.

 

RL

RK

B

1.2.2\

Section Structure

 

 

 

 

 

 

 

Coronal view of the Ao and accompanying infe-

 

 

 

 

rior vena cava (IVC).

 

IVC

 

 

1.2.3\

Measurement Method

 

Ao

 

 

 

 

 

 

and Normal Value

 

 

 

 

The transverse (left–right) diameter on the maxi-

 

 

 

 

mum coronal section is measured with cursors

 

 

 

 

placed at the inner surface of the artery wall,

 

 

 

B

from one side to the other.

RL

RK

IVC

Ao

Fig.9.2  Lateral lumbar scan: coronal view of the abdominal aorta

1.2.4\ Clinical Application Value

This section is used mainly in cases of obesity, massive ascites, and abdominal distension, which may present difficulties for regular ultrasound examination of the Ao. The lumen and artery wall structure can be evaluated in this view, and the IVC can be evaluated as well.

1.2.5\ Notes

1.2.1\ Scanning Method

The patient should be on an empty stomach for 8–12 h, and should be in a left (or right) lateral

There is some error in the measurement of the Ao diameter; an error less than 0.5 cm is usually considered of no statistical significance.