Ultrasound is called ultrasound because its frequency exceeds the limit of human hearing.
When the wave generated by ultrasound propagates in the human body, it is a method to diagnose diseases by displaying the reflection and attenuation rules of various organs and tissues in the body to ultrasound through the oscilloscope screen.Ultrasound has good directionality. When encountering tissues and organs with different densities in the process of transmission in the human body, there are reflection, refraction, absorption and other phenomena.According to the distance, intensity and number of echoes displayed on the oscilloscope screen, and whether the attenuation is obvious, the activity function of some organs in the body can be displayed, and can accuratelyidentifyWhether the tissues and organs contain liquid or gas, or whether they are substantiveorganization。
Chinese name
Ultrasonic inspection
Meaning
Its frequency exceeds the limit of human auditory range
Ultrasound is an advanced medical technology with good directionality. It is a diagnostic method commonly used by doctors.ultrasonicIt is divided into Type A (oscillographic) method, Type B (imaging) method, and Type M（Echocardiography）Method, fan type (two-dimensional echocardiography) method, Doppler ultrasound method, etc.In fact, the B-type method can be divided into three categories: line scanning, sector scanning and arc scanning, that is, sector scanning should be included in the B-type method.
Type A method
Type A method is commonly used to judge whether there are abnormal lesions from the amplitude, number and sequence of waves on the oscillogram.In the diagnosis of cerebral hematomabrain tumor, cyst, and chestAscites swelling、Early pregnancy、Hydatidiform moleAnd other aspects are relatively reliable.
Various sectional images of the heart can be obtained by fan method, and different manifestations of the heart in systolic and diastolic periods can be observed.Because the graphs it sees are more comprehensive, the diagnosis range is much more than that of the M-type method, and it is more detailed
And exact.In addition, this method can also be used to diagnose liver, gallbladder, pancreas, spleen, brain, gynecology and obstetrics.
Color Doppler ultrasound refers to "color Doppler diagnosis".It adds spectrum blood flow on the basis of ordinary B-ultrasound. Generally speaking, color ultrasound has more blood flow functions than B-ultrasound, which is of little significance in some examinations!
Is B-ultrasound harmful to human body?
B-ultrasound is a routine examination for patients in the hospital. Up to now, there has been no report of damage to patients. It is one of the six major imaging diagnostic equipment in the medical community.
Can you see clearly by B-ultrasound?
Imaging is justclinical diagnosisThe auxiliary examination of imaging, that is, looking at images and guessing objects, cannotQualitative diagnosis。Its performance is high, medium and low echo images. It can only be diagnosed by combining the clinical performance of patients and their own experience with clinicians. Any disease cannot be completely dependent onB-mode ultrasonographyAnd sure!
Scientific detection
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ultrasonicIts clinical application in medicine began more than 70 years ago, andX-rayDifferent, there is not enough evidence to prove that ultrasound hasTeratogenic effect。However, because human beings have not accumulated long-term data on the impact of ultrasound on the human body, experts suggest that the principle of minimization should be adopted for general prenatal ultrasound examination, and multiple ultrasound examinations should not be carried out for reasons other than medical diagnosis.
But that doesn't mean doingB-ultrasonic inspectionThe less the better. In addition to two necessary inspectionsmother-to-beAccording to the doctor's advice, necessary examinations should be carried out.For example, when the expectant mother has symptoms of abortion, the doctor may need to pass theB-mode ultrasonographyconfirmfetusAt this time, we must not persist in worrying about the impact of B ultrasound on the fetus.There was a expectant mother who bled during pregnancy. The doctor hoped to determine whether the baby was alive through ultrasonic examination, but the expectant mother refused to continueFoetus protection, it happenedFetal deathThe tragedy of.
Mothers to be should not be very worried because they have done one or more ultrasonic examinations than others. In fact, the impact of psychological tension and bad mood on the fetus is far greater than the impact of ultrasound itself on the fetus.
preparation
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1、 Examination requiring fasting:
Check the upper abdomen, such as liver, gallbladder, bile duct, pancreasadrenal gland, renal artery, left renal vein, abdominal blood vesselthe peritoneumRear, upperAbdominal massAnd so on. It needs to be checked after an empty stomach. Usually, it starts fasting after dinner the previous day. The next morning, it needs to be checked on an empty stomach to ensure that the gallbladder and bile ductbileFill, and reduce the interference of food and gas in gastrointestinal tract, otherwise the examination results may be greatly affected.The ultrasonic image quality of these parts is easily affectedIntestinal qiInterference, so patients with abdominal distention or constipation should take digestive drugs before examination to help exhaust or useSuppositories GlycerolOr some laxatives to help defecate.
Preparation before ultrasonic inspection
In addition, transesophageal echocardiography must be scheduled in advance. The doctor will instruct the patient to have an empty stomach on the day of examination. The patient should also carry the results of transesophageal echocardiography so that the doctor can quickly understand the condition andesophagusThere is a target in the inspection.Since this examination is a semi traumatic examination, which has certain risks (generally not high), family members and the patient should sign the informed consent form for the examination, so a direct family member should accompany the examination.
2、 The bladder needs to be filled (commonly known asSuffocation）Inspection of:
Check pelvic cavitybladder、prostate、Seminal vesicle gland、ureterLower sectionLower abdominal mass、uterus, AccessoriesEarly pregnancyThe bladder needs to be filled.You can drink 1000-1500ml of water (or various drinks) 1-2 hours before the examination. Do not urinate after drinking waterBladder fillingTo facilitate inspection.Those who are pregnant for more than 3 months do not need special preparation, but they are suspected to havePlacenta previaThose who are still need to drink water to fill the bladder before doing the examination.
1. Before examining the abdomen, the patient needs to fast for more than 8 hours to ensure that the gallbladder bile duct is fullbileAnd reduce the interference of gastrointestinal contents and gas.Usually, the fasting starts after supper the previous day, and an empty stomach examination is carried out the next morning.In the afternoon, the examiner fasted at noon.
2. BladderprostateThe examiner should fill the bladder.Please drink 1000-1500ml of water (or various drinks) 1-2 hours before coming to the hospital. Do not urinate after drinking water, so that the bladder can be properly filled to facilitate the examination.
3. X-ray gastrointestinalradiographyThe barium agent is a strong reflection and absorber of ultrasound.Barium remains in the gastrointestinal tract near the gallbladder and bile duct, which will affect the ultrasonic examination. Three days after X-ray gastroenterography,CholangiographyDo it in two daysUltrasonic examination。
4. Patients undergoing gastroscopy and colonoscopy should have ultrasound examination two days later.
5. Abdominal flatulence affects the observation of gallbladder, bile duct and pancreas images, which can be takenLactinogenyThe tablets were examined three days later.
4、 Preparation for gynecological and obstetric patients before examination:
1. When performing gynecological transabdominal examination and pregnancy less than three months, in order to avoid the influence of intestinal contents, especially gas, it is advisable to empty stool before examination, so that there is no fecal mass or barium residue in the intestine.
2. Drink 1000-1500 ml of water (or various drinks) 1-2 hours before coming to the hospital. Do not urinate after drinking waterbladderModerate filling to facilitate examination. Obstetrical patients who are pregnant for more than 3 months have no special preparation, but are suspicious in the middle and late pregnancyPlacenta previaThose who are still need to drink water to fill the bladder before doing the examination.
VHeart, limb blood vessels, thyroid, breastHydrothorax, gynecological transvaginal examination and transcranial DopplerUltrasonic examinationThere are no special requirements.
