Summary of basic knowledge of ultrasound(part four)

Section 9 Superficial Organ Ultrasonic Examination Measurement Methods and Normal Values
Thyroid Ultrasound Measurement Methods
(1) Thickness (anterior-posterior diameter) and width (left-right diameter) measurement of the thyroid gland
1. Standard measurement section: in a series of cross-sections of the thyroid gland, the thickest and widest part of the thyroid parenchyma is selected as the standard section, and the pressure of the probe should be as light as possible.
2. Measurement location: respectively selected at the edge of the hyperechoic line of the capsule at the thickest and widest parts of the thyroid gland.
3. Normal adult reference value (cm): the thickness of the left and right leaves is 1.5~2.0cm,
The width is 2.0~2.5cm, and the thickness of the isthmus is less than 0.5cm.

(2) Measurement of the long diameter (upper and lower diameter) of the thyroid gland
1. Standard measurement section: In a series of longitudinal sections of the thyroid gland, the longest part of the thyroid parenchyma is selected as the standard section, and the pressure of the probe should be as light as possible.
2. Measurement locations: respectively selected on the edge of the hyperechoic line of the capsule at the longest part of the thyroid gland.
3. Normal adult reference value (cm): the length of the left and right leaves is 4.0~6.0cm,
The length of the isthmus is 1.5~2.0cm.
Section 10 Measurement Methods and Normal Values of Vascular Ultrasound Examination
Because blood vessels run long or short, the same blood vessel has thick and thin diameters along with the proximal and distal centers, and the blood flow speed varies. Therefore, it is necessary to describe which section of the vessel and which point to measure during ultrasonic measurement.
Here are a few common measurement methods and normal reference values for peripheral blood vessels:
one. Carotid artery
1. Common carotid artery: The normal common carotid artery blood flow spectrum curve is in the shape of three peaks, which is a laminar flow spectrum. There are two peaks in the systolic period, the first peak is greater than the second peak, and there is a notch between the two peaks. The early diastolic growth rate forms the first peak. Three peaks, all three peaks are positive spectrum, and there is continuous low-speed positive blood flow throughout the diastolic period. The systolic peak flow velocity was 91.3±20.7cm/s, the diastolic peak flow velocity was 27.1±6.4cm/s, and the resistance index was 0.7±0.05. The inner diameter of the common carotid artery is about 6.6~7.5mm, and the wall thickness is about 1mm.
two. abdominal aorta
The shape of the normal abdominal aortic blood flow spectrum curve is positive unimodal, with a narrow frequency band, which is a laminar flow spectrum. The acceleration and deceleration of the blood flow in the systolic phase are faster, and there may be a small negative spectrum in the early diastole, and the diastolic phase is positive. low blood flow. The normal peak velocity range is about 90~130cm/s. The inner diameter of the proximal segment of the abdominal aorta is about 2.0-3.0 cm, the middle segment (pancreas level) is 1.6-2.2 cm, and the distal segment (bifurcation) is 1.3-1.7 cm.
three. inferior vena cava
The normal inferior vena cava blood flow spectrum line is the centripetal blood flow during the systolic period, the second centripetal blood flow appears when the flow velocity increases again during the rapid cardiac filling period, and the low-speed centrifugal blood flow in the middle and late diastole is above the baseline. The first peak flow velocity can reach 31.3±8.2cm/s, the second peak flow velocity can reach 25.0±8.1cm/s, and the third peak flow velocity can reach 8.6±2.2cm/s. The inner diameter (posterior segment of the liver) is 18.8±3.9mm when exhaled and 11.3±4.9mm when inhaled.
Four. deep veins of lower extremities
Including the deep femoral vein blood flow spectrum curve in the resting state is a spontaneous collection of blood flow spectrum, which is characterized by single-phase, low-speed centripetal blood flow that changes with respiratory movement, and the shape of the curve fluctuates with breathing waves. During deep inspiration or Valsalva test, the blood flow in the large and medium veins stops, and when the distal extremities are pressurized or elevated, the blood flow in the proximal segment accelerates.