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On the level of understanding of the general public for the hospital inspection equipment, in addition to electrocardiograms, X-ray, the most familiar than the ultrasound. 80's, ultrasound diagnostic imaging technology in obstetrics has been an unprecedented expansion of the scope of application, which is to assess the fetal structure of the anomaly, multiple pregnancies, the size of the fetus as well as the cycle of pregnancy, and so on, has a very important significance, obstetric ultrasound has a very important meaning. It is of great significance for the evaluation of fetal structure abnormality, multiple pregnancy, fetal size and pregnancy cycle, etc. Obstetric ultrasound is famous for its three advantages of painless, non-invasive and fast. According to the data, in countries and regions with faster development of medical technology, more than 90% or even 100% of pregnant women receive ultrasound examination more than once during pregnancy. However, recently, the safety of obstetric ultrasound, which originally gave people peace of mind, has been questioned, and individual medical experts have even suggested that ultrasound should be prohibited in the third trimester of pregnancy. This is a serious medical topic. So how does Prof. Kong Qiuying see this issue?
Professor Kong, who is as quick in thought as he is in action, and who has worked hard in the field of diagnostic, clinical and experimental obstetric ultrasound, and who has seen tens of thousands of women in labor, enthusiastically accepts the interview. Professor Kong briefly introduced: "Ultrasound is a kind of non-ionizing radiation, it is a physical factor, a kind of energy, then there is also a question of safe dose. At present, there are diagnostic ultrasound and therapeutic ultrasound in clinic, and the power of the former is 100 to 1000 times lower than the latter. whether ultrasound is harmful or harmless to human body or fetus, the key lies in the ultrasound dosage, which is also called the threshold safe dosage. That is, when the dose of ultrasound used in obstetrics is less than this value, it is harmless, and conversely, when it is greater than this value, it may produce harmful effects or injury. As far as the dose is concerned, therapeutic ultrasound has some damage or effect on the human body, while diagnostic ultrasound, in a regular hospital, under the operation of a strictly professionally trained doctor or technician, and the power of the ultrasound instrument is less than 10 milliwatts/square centimeter, it is not so harmful to the human body or the fetus."
Professor Kong took a break and continued, "In addition to the dose of ultrasound being related to the power level of the instrument, another important issue is the time of radiation. Some people suggest that ultrasound is prohibited in the third trimester of pregnancy, but I think the word 'prohibited' is too absolute. If the clinical diagnosis needs, can still do ultrasound, otherwise the delay in diagnosis, the problematic fetus failed to take timely measures, the consequences will be unimaginable." Professor Kong said, for example, a woman more than three months pregnant, bleeding for more than 20 days, the doctor ordered ultrasound to find out whether the fetus is viable, but she saw the newspaper published a "ban" ultrasound, then refused to check, continue to "preserve the fetus", and finally due to the fetal death of the uterus is too long, the coagulation mechanism is impaired, scraping the uterus. In the end, because the fetus had been dead in the uterus for too long, her blood clotting mechanism was impaired, causing hemorrhage when scraping the uterus. This heavy lesson is worthy of people's deep thought. Strictly control the examination time in the ultrasound academic field of experienced, deep attainments, galloped across the country, exploring nearly 20 years, pick up the probe to be comfortable, easy to talk about the sword of Prof. Kong she went on to explain: "ultrasound diagnostic safety is indeed ultrasound medicine in the cutting-edge basic research issues, which relates to the diagnostic ultrasound images in the correct use of obstetrics and gynecology and promotion, and the relationship to eugenics and fertilization. It is related to eugenics. Ultrasound in medicine has a very wide range of applications, providing clinicians with information that is both accurate and convenient, and has its own unique features. For example, fetal malformations cannot be touched, early diagnosis and early treatment by ultrasound, as well as monitoring of fetal development, the amount of amniotic fluid, the normal placenta have a decisive role in reducing the perinatal neonatal mortality rate, and eugenics has a positive significance. At present, almost all hospitals, including most primary hospitals, have ultrasound diagnostic equipment. The problem is that many primary hospitals do not have a good grasp of the indications for ultrasound examination, and do ultrasound too indiscriminately and do not have a good grasp of the time of irradiation." Professor Kong solemnly emphasized that "pregnant women should not do ultrasound examination time more than 5 minutes, the instrument power and continuous abdominal irradiation time to determine the ultrasound dose."
In order to grasp and understand the situation more scientifically and accurately, Prof. Kong has led his graduate students to do careful and detailed basic research in recent years, and found that in specific research subjects, after 5 minutes of ultrasound irradiation, the cornea of the fetus undergoes mild edema, and the lipid peroxidation reaction of the chorionic villi is mildly affected, but this is reversible, and the irradiation for 20 minutes has a greater effect and is irreversible. The paper of this research has been published and exchanged at the International Ultrasound Symposium held in Beijing in August 1998, which was well received and recognized by experts. Prof. Feng Ruo, Chairman of China Ultrasound Safety Committee, commented on this study, "The content of this study pushes the ultrasound safety research to a new level, which may still be a pioneering step and a new breakthrough in the international arena." Prof. Kong's study makes obstetric ultrasound appear "justified" in the clinic, that is, early pregnant women can do ultrasound examination when necessary, but each examination time should be strictly controlled within 5 minutes. The doctor's attitude is to be positive and cautious, serious and conscientious," he said.
Professor Kong took out a stack of clinical data and several scientific papers, and concluded that the application of ultrasound in obstetrics has its own clear guiding principles, which is a requirement for people in the field, but also for readers to understand, and turned into a "pregnant women's instructions", so that everyone has a clear idea of what is going on.
The first: there is a diagnostic need, should be actively used ultrasound, such as doubt whether the fetus is alive or there is no malformation, amniotic fluid is too much.
Note 2: the examination adhere to the principle of minimum dose, as far as possible, the use of the smallest radiation intensity and the shortest possible time, to obtain the necessary diagnostic information, an examination time (probe contact with the abdomen time) should be less than 5 minutes; ultrasound instrument power should be less than 10 milliwatts / square centimeter (manufacturers generally in the factory has been measured in the safety of this threshold).
Third: It is strictly prohibited for medical personnel to use ultrasound to identify the sex of the fetus in order to decide whether to take it or not. It has been reported that prolonged exposure to fetal testes can damage spermatogonia.
Note 4: Ultrasound examination of the fetus should not be carried out solely for commercial purposes and publicity needs, and the duration of radiation exposure should not be extended arbitrarily.
Note 5: Early pregnancy without special circumstances generally do not need routine ultrasound. The whole pregnancy generally do ultrasound examination 1 ~ 2 times. If there is a need for multiple examinations to confirm the diagnosis, the irradiation time must be mastered.
Color ultrasound is not the icing on the cake, some wealthy couples take it for granted that, like a television set, color is naturally better than black-and-white, and ultrasound should be the same, color ultrasound is better than black-and-white ultrasound, so it is often heard that pregnant women or their husbands yell at the doctor to do a color ultrasound. This is a misconception. Professor Kong smiled and said: "color ultrasound in obstetrics application is not characteristic, color ultrasound color blue-red only represents the direction of blood flow, which is beneficial to the diagnosis of cardiac blood vessels, but only plays an auxiliary role in the diagnosis of obstetrics and gynecology diseases. The use of black and white two-dimensional ultrasound is generally sufficient, not to mention that color ultrasound has a high dose, obvious biological effects, and negative effects on the fetus, so it should be used with caution." Professor Kong concluded by emphasizing again and again that whether it is black and white ultrasound or color ultrasound, it should be examined under the guidance of a specialist, and should not be used by the pregnant woman or her family members to make unscientific demands on the "high-grade", "low-grade" or "high-consumption" of the instrument. "The first thing you need to do is to get your hands on a new one, and you'll be able to do that.