Ultrasound of the pleural cavities
Last reviewed: 20.11.2021
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Indications for the study of ultrasound of the pleural cavities
Echography will help to identify fluid in the pleural cavity and to locate small accumulations of fluid if it is necessary to aspirate. If the radiographic study has confirmed the presence of fluid in the pleural cavity, then the echography is only shown if aspiration is necessary under control if there is a limited effusion or with a slight exhalation.
There is no need to perform every pleural puncture under ultrasound control.
Preparation
- Preparation of the patient. No patient preparation is required.
- Position of the patient. If possible, the patient should be examined in a comfortable sitting position. Apply the gel arbitrarily to the lower part of the chest from the side that will be examined.
- Select the sensor. Use a 3.5 MHz sensor. Use a 5 MHz sensor for children and thin adults. Choose the smallest possible diameter sensor for scanning along the intercostal spaces. If there is only a large sensor, the shadows from the edges will be superimposed on the image, but the necessary information can still be obtained.
- Adjustment of sensitivity of the device. Set the sensitivity level to obtain the optimum image.
Scanning techniques
The sensor is placed on the intercostal spaces perpendicular to the patient's skin. In this anechoic fluid can be visualized above the diaphragm in the pleural cavities. Lungs have a high echogenicity, since they contain air.
First, scan the suspicious area and compare it with the radiography data; then scan at all levels, since the effusion can be delimited and not detected in the lowest-lying areas of the pleural cavities (in the rib-diaphragmatic sinus). Change the position of the patient to determine the displacement of the fluid.
Pleural effusion is hypoechoic or mild echogenicity, sometimes thick septa are defined. Liquid blood and pus are also anechogenous, but septums can give reflections. It is not always possible to differentiate the fluid and solid formations of the pleura or peripheral parts of the lungs. Turn the patient to different positions and repeat the test. The fluid will move, even if there are partitions or a large amount of liquid. Peripheral lung tumors or pleural tumors will not move. To confirm the diagnosis, an aspiration biopsy is necessary.