1. Is ultrasound harmful to human body?
The working principle of ultrasound diagnostic instrument is similar to that of bat predation, both of them send out to receive and process ultrasonic waves to obtain useful information.
Ultrasound is a frequency higher than 20,000 Hz sound waves, it is not radioactive, safe for human body, harmless, its use is very wide, almost involved in various industries. Medical ultrasound diagnosis is widely used, both to diagnose and to use its principles for the purpose of treating certain diseases.
In general, we are most often exposed to ultrasound examinations of conventional abdominal organs such as liver, gallbladder, pancreas and spleen; obstetrical and gynecological ultrasound examinations such as maternal examination of female uterine attachments; genitourinary ultrasound examinations such as kidney, ureter and bladder; superficial organs such as thyroid, breast and superficial small lumps; and vascular and cardiac ultrasound.
In addition to the more routine examinations mentioned above, ultrasound examinations can also be used for brain, eye, skeletal muscle, imaging, interventional treatment, etc. Using ultrasound probes with different frequencies and different focusing methods can examine different organs, the most commonly used ones such as abdominal low frequency convex array probes, superficial high frequency linear array probes, cardiac ultrasound phased array probes, intracavitary probes, etc.
2. What is the fluid applied during the examination? Is it harmful to human body?
The coupling agent applied before the examination is a water-soluble liquid, colorless and transparent gel, which is non-toxic to human body and can be wiped clean or washed with warm water after the examination. The purpose of applying coupling agent is to make good contact between the probe and the skin, which is conducive to the conduction of ultrasound, improve the imaging quality and make the image clearer.
3. Does color ultrasound = color TV?
"Doctor, why is there no color image on the screen of the instrument? Are you a color ultrasound?" I believe every patient has asked a similar question. With the continuous development of medical conditions, most patients are now examined with color ultrasound. But why is the screen the doctor is looking at so different from the color TV at home? The meaning of the word "color" in color ultrasound is, in layman's terms, to indicate the direction of blood flow in the blood vessels, generally in red or blue. Doctors use the direction of blood flow to determine whether the target organ has a blood supply and the direction of blood flow to help diagnose diseases. Therefore, ultrasound is in color, but it is not the same as a color television set in your home.
4. Why do ultrasound examinations require fasting?
Ultrasound diagnosis has a high resolution for tissue structures, while at interfaces with high contrast such as solid-gas or liquid-gas, ultrasound is difficult to pass through and almost totally reflected. If after eating, some gas can be swallowed with the food, so that the intestinal gas increases, and some foods such as bean products themselves also tend to produce gas, which limits the penetration of sound waves when performing abdominal ultrasound, the image display will not be clear, and after the gastrointestinal tract is filled with food, the food will form the same sound image as lumps and stones, leading to misdiagnosis. Therefore, it is necessary to fast for 6-8 hours when performing abdominal organs, such as liver, gallbladder, pancreas, spleen, kidney, large abdominal vessels, abdominal cavity, retroperitoneum and intestinal examination. The contraction of the gallbladder becomes smaller after eating, which makes it difficult to distinguish whether it is a physiological or pathological change, and also affects the display of lesions in the gallbladder, such as gallbladder stones and polypoid lesions. In addition, for patients with frequent abdominal distension, it is recommended to eat a light diet the night before the examination and take appropriate medication to promote the digestive tract before the examination.
5. Why is it necessary to hold urine for some ultrasound examinations?
For ultrasound examination of bladder, ureter, prostate and seminal vesicles, unmarried women with more vaginal bleeding, and pregnant women in the first 3 months of pregnancy, it is necessary to hold urine. The purpose of holding urine is to fill the bladder to reduce intestinal gas interference and to provide a good window for examination transmissions. When doing a gynecological examination, it is generally required that the bladder urine volume is 300-400ml. The sign of a well-filled bladder is a flat lying position with a slightly convex lower abdomen, and the probe can press down and be tolerated when pressurized.
6. Why do I have to hold my urine for the same gynecological ultrasound, but she does not have to hold her urine?
With the advancement of technology and the diversity of probes, gynecological examinations can be performed with two types of probes, namely transabdominal and transvaginal ultrasound, with different populations: transabdominal ultrasound for all women, including pregnant women; transvaginal ultrasound for married women and pregnant women with suspected placenta praevia.
Advantages of transvaginal ultrasound.
①The frequency of the transducer is higher than the frequency of the transducer routinely used in the abdomen, which significantly improves the resolution and shows the pelvic organs and smaller lesions more clearly.
②No need to hold urine, which reduces the pain of holding urine.
③For obese patients, vaginal ultrasonography does not require passing through multiple layers of abdominal tissue and thicker fat, with significantly less interference and clearer images.
Disadvantages of transvaginal ultrasonography.
High probe frequency, limited penetration and limited display of higher located organs and larger lesions. For example, transvaginal ultrasound cannot show the whole picture of some cervical cases after cesarean section, ovaries in high position, large fibroids or multiple fibroids, large pelvic masses or masses with long and high tissues, and requires combined scanning with transabdominal ultrasound to give a more accurate diagnosis. Not all women are suitable for a negative ultrasound. It has its contraindications.
7. stomach discomfort do not want to do colonoscopy, but can still do gastric ultrasound?
With the development of science and technology, the ultrasound department of Ordos Hospital of Traditional Chinese Medicine has carried out gastric ultrasonography this year, which has richer clinical experience in the diagnosis of gastritis, gastric tumor (submucosal tumor, exophytic tumor), gastric ulcer, gastric polyp, gastric prolapse, gastric dyskinesia, fundic varices, duodenal bulb ulcer and other lesions. Gastric ultrasonography is a well-established technique with a simple procedure, with oral co-contrast agents taken under the guidance of a physician before the examination on an empty stomach. It has a high diagnostic value for gastric diseases, especially gastric tumors and ulcers, and the examination is flexible, convenient, non-invasive, painless, less expensive, with the advantages of real-time dynamics and repeatability, which can make up for the shortcomings of traditional examination methods.
