Main indications
The most common causes are swelling and pain in the area of the gland, aggravated by eating (a characteristic sign of salivary stone disease), dry mouth, a lump under the lower jaw or in front of the ear. Ultrasound clearly visualizes stones in the ducts, signs of acute and chronic sialadenitis, cysts and tumors, as well as the condition of regional lymph nodes. The method is the first line of diagnosis: it is accessible, safe and in most cases provides an answer without additional research. If a tumor is suspected, the examination is supplemented with a fine-needle puncture under ultrasound guidance.
Why ultrasound is the first line method
Ultrasound does not use ionizing radiation, is fast, inexpensive, and provides images in real time. Therefore, it begins with the diagnosis of most diseases of internal organs, thyroid and mammary glands, blood vessels, joints and soft tissues.
A separate advantage is the ability to evaluate not only structure, but also movement: blood flow in the vessels, heart contractions, peristalsis, and fetal movements. Neither CT nor MRI in standard mode show this.
Ultrasound modes
- B-mode - a conventional two-dimensional gray scale image of the organ structure
- Dopplerography - assessment of the speed and direction of blood flow in the vessels
- duplex scanning - a combination of vessel imaging and blood flow analysis
- 4D - volumetric image in real time
What influences the quality of research
Ultrasound does not pass through air and does not pass well through dense bone tissue. Therefore, gases in the intestines interfere with examination of the pancreas, and the lungs and brain of an adult are inaccessible for examination. This explains the preparation requirements: diet and fasting study significantly improve visualization.
The second important factor is the doctor: ultrasound diagnostics largely depends on the experience of the specialist, since the image is assessed at the time of the examination.