How to do a bone density test
There are 4 kinds of bone density tests: (1) Single Photon Absorptiometry (SPA): The general selection of the site for the radius and ulna in the distal 1/3 of the junction (the middle and lower third of the forearm) as the measurement point. Generally, right-handed people measure the left forearm, and "left-handed people" measure the right forearm. This method is more widely used in China, and the equipment is simple, inexpensive, and suitable for epidemiologic census. The method can not determine the bone density of the hip bone and the central axis bone (vertebrae).
(2) Dual-energy X-ray absorptiometry (DEXA): through the X-ray tube ball through a certain device to obtain two kinds of energy, that is, low-energy and high-energy photon peaks. After such photon peaks penetrate the body, the scanning system will receive the signals sent to the computer for data processing, resulting in bone mineral content. The instrument can measure the amount of bone in any part of the body with high accuracy and less harm to the human body. The radiation dose for detecting one part of the body is equal to 1/30 of a chest X-ray and 1% of a QCT. There is no radioactive source decay problem, has been gradually carried out in major cities in China, the prospect is promising.
(3) Quantitative CT (QCT): In the past 20 years, computerized tomography (CT) has been widely used in the field of clinical radiology. QCT can accurately select a specific part of the bone measurement of bone mineral density, can be assessed separately the spongy bone mineral density of the cortical bone. Clinical fractures caused by osteoporosis are often located in spongy bone such as the spine, femoral neck, and distal radius, and QCT can be used to observe bone mineral changes in these areas, but it is currently only used in research studies because of the large number of X-rays received by the subjects.
(4) Ultrasonography: It has attracted widespread attention because it is radiation-free and sensitive to fracture diagnosis. The use of acoustic wave conduction velocity and amplitude attenuation can reflect the amount of bone mineral content and bone structure and bone strength, and has good correlation with DEXA.
May I ask the doctor how the bone density test is done?
It takes about a minute to do a bone density test. Some of them used to take off their shoes and socks, which was a pain in the ass. Nowadays, most people use ultrasound bone densitometers, which can be measured on the wrist in a short time, with a T-value and a Z-value, and the doctor will explain the meaning of each value.
What condition to do bone density test
1, young women: bad habits are constantly disturbing the health of the city people, osteoporosis is also gradually appeared earlier. In the age group of 25 to 35 years old, more than 50% of white-collar women's bone loss is more serious than men, the incidence rate is significantly higher than men. A large proportion of women who feel back pain are early symptoms of osteoporosis. Nowadays, many young women are prone to osteoporosis due to dieting, sitting too much and not moving enough, and eating an unbalanced diet. Men who smoke cigarettes and drink heavily: Due to smoking and alcohol abuse, as well as metabolic diseases such as obesity, diabetes, and high blood pressure, middle-aged men begin to lose bone mass. If you experience symptoms such as easy fatigue, aching and tiredness around the body, lethargy, excessive sweating, numbness, love of cramps, etc., it is necessary to go for a bone density checkup. 2. Children who like carbonated beverages: The risk of bone fracture for children who often drink a lot of carbonated beverages is three times higher than that of other children. Children who watch too much TV or computer are more at risk of osteoporosis in adulthood due to lack of outdoor exercise. Also children who are obese and picky eaters should have their bone density checked. Post-menopausal women: 3. When women's menopause comes, the decline of bone mass is obvious, and then the measurement of bone density becomes quite important. Measuring bone density to prevent osteoporosis is a must for middle-aged and elderly women after the age of 50. If there are additional risk factors for osteoporosis, such as using corticosteroids, smoking cigarettes, or drinking large amounts of coffee over a long period of time, then it is important to have the test done annually.4 People with renal insufficiency, diabetes mellitus, chronic liver disease, and hyperparathyroidism.5 Elderly people are the key group of people with osteoporosis, and must pay attention to their bone density checkups.6 People with low levels of sex hormones.7 People with family histories of related bone disorders8, X-ray examination shows that osteoporosis changes in people. 9, pregnant women in the third and sixth months of pregnancy to check a bone density, timely supplementation of calcium. 10, taking drugs that may affect bone mineral metabolism people.
How to measure bone density
In the past, the most common diagnosis of bone lesions is to do X-ray flat film examination. However, in recent years, bone density testing has become increasingly popular. The main clinical value of the bone density test is the early diagnosis of osteoporosis, the function is to determine the bone mineral density (BMD), bone mineral content (BMC), and X-ray film can only be seen when the bone loss of more than 30% -50% of the osteoporosis changes in the clinic, mostly used for bone fractures, bone tumors and other bone disease diagnosis, the two have their own strengths, can not be equated. Bone density test is the earliest use of radionuclides produced by the density of rays through the human body to determine the body's bone content, there are single-photon and two-photon products. As radionuclides have nuclear decay, they are not easy to store, and the ray source is unstable, resulting in poor precision, and are not very widely used in applications. Nowadays, the main bone density test is dual-energy X-ray bone densitometer (DXA). Because this kind of ray can penetrate bone and soft tissue etc. at the same time, and different tissues react differently to two kinds of energy X-rays, so it can be corrected and calculated by mathematical formulas to obtain the data of determinants. Bone density testing can be used both to diagnose osteoporosis and to measure the composition of the entire body, helping to understand the relationship between bone, muscle, and fat, indicators that are important in the prevention and treatment of osteoporosis and obesity. The image obtained with dual-energy X-rays is more precise, clearer and more accurate than that obtained with radionuclide-generated rays, but not as large as the energy of ordinary X-rays, which is almost negligible and not enough to cause radiation damage to the human body. It is because of its advantages that bone density test can now be used as a routine physical examination program for middle-aged and elderly people over 45 years old, especially for menopausal women. In addition to the diagnosis of osteoporosis, it is also used to predict osteoporotic fractures, guide treatment and monitor the effect of treatment, determine the amount of bone in endocrine and metabolic diseases, and assess the growth and nutritional status of children. Middle-aged and elderly people should have an annual bone density test for early detection of osteoporosis and symptomatic treatment. Doing so can stop bone loss at an early stage and slow down aging, which is very helpful in improving the quality of life of the elderly. It is currently believed that there are no absolute contraindications to bone density testing, and that pregnant women should be cautious.
What should I look for in a bone density test?
As we age, a large amount of calcium nutrients in the body are consumed, and calcium needs to be transferred from the bones into the bloodstream, resulting in a decrease in bone density, leading to osteoporosis. Long-term transfer of bone calcium into the bloodstream may lead to an increase in the amount of calcium in blood vessels, tissues, and cells. Causing peripheral numbness, neurasthenia constipation, drowsiness, atherosclerosis, coronary heart disease, diabetes, tumors and many other age-related diseases. And bone density test is the main indicator of bone strength and calcium content in the body. Bone density test is an advanced technology of modern medicine, it is through the way of scanning, bone mineral content of the examinee to determine, provide valuable comparable data, diagnosis of a variety of systemic diseases on the bone metabolism of the impact are very important role. Does it hurt to have a bone densitometry test? Nowadays, most of the bone densitometers have the advantages of high accuracy, simple operation and no damage. No special preparation is needed before the examination, and the measurement is painless, similar to CT and X-ray examination. The results are statistically processed by a computer. Generally speaking, the bone density test is performed one part at a time, and the results reflect the bone density value of a certain part of the body, while the whole body needs to be evaluated comprehensively. What do I look for in a bone density test? 1) T-value is the standard deviation (SD) of the bone mineral density (BMD) obtained from the test compared to the BMD of normal young people, which is the most meaningful value for the diagnosis of osteoporosis. 2) Z-value is the value obtained by comparing the BMD measured by the examination with the BMD of normal people of the same age. Although the Z value is not significant in diagnosing osteoporosis, it can reflect the severity of osteoporosis.
What is the use of bone density test
Bone density test is mainly to check the calcium deficiency, risk of fracture, etc., and related to this is osteoporosis, osteoporosis is a quiet epidemic, because osteoporosis can not have any symptom before a fracture occurs, and it is most common in postmenopausal women and older men, the discovery of osteoporosis can not rely on the self-feeling, do not wait until you find themselves Don't wait until you realize you have back pain or a fracture to seek treatment. The reason is that if osteoporosis causes a fracture of the spine or hip, there will be serious consequences.
1) Detection of bone mineral content, to assist in the diagnosis of calcium and other nutritional deficiencies, to guide nutritional intervention, treatment;
2) According to the age of the corresponding bone mineral density status, to predict the state of bone nutrition and growth rate;
3) Diagnosis of osteoporosis Doctors use the bone mineral density measurements to determine whether the patient suffers from osteoporosis.
4) Fracture risk assessment Bone mineral density (BMD) can predict the risk of fracture and analyze how likely you are to have a fracture through scientific methods, so that you can have a clear idea.
In addition, the bone density examination is adapted to children, adults, pregnant women, the elderly and so on, through the bone density examination targeted to do physical health adjustment.
The new generation of ultrasound bone densitometer
Working Principle: The ultrasound probe emits ultrasound by stimulating an electrical pulse to the ultrasound probe, the ultrasound wave penetrates the heel of the tested person and reaches another ultrasound transducer, due to the ultrasound wave through the different bone, the ultrasound speed and attenuation are not the same, through the calculation of the SOS (ultrasound speed) and the BUA (broadband ultrasound attenuation), the ultrasound bone densitometer will be able to measure the bone density of the tested person, and then the bone density of the tested person will be able to be measured. By calculating SOS (ultrasound speed) and BUA (broadband ultrasound attenuation), the ultrasound bone densitometer derives the T-Score (T-value), Z-Score (Z-value), BQI (Bone Quality Index) and other parameters of the subject, which can be displayed on a computer or printed on a printer for the doctor's diagnosis and reference.
Scope of application: To detect the bone density value of heel area by ultrasonic wave.
Main Technical Parameters
Safety Characteristics
Type of Electric Shock Prevention: Class I Device
Application Part: Type B Application Part
Operation Mode: Intermittent Loading, Continuous Running
Usage in Air-Mixed Gases: It cannot be used in the case of flammable anesthetic gases mixed with air or flammable anesthetic gases mixed with oxygen or nitrous oxide. The device can not be used with flammable anesthetic gases mixed with air or with oxygen or nitrous oxide.
Performance Parameters
Ultrasonic working frequency: 0.5MHz, error: ±10%.
Ultrasonic speed error: ≤ ± 2%
Measurement time: ≤ 25s
Calculation of BUA using the frequency range: 200-500kHz
Wide-band ultrasonic attenuation (UBA) measurement repeatability: ≤ ± 5%
Main features
Input information: the patient's name, age, gender, etc.
Parameters of measurement, measurement of the patient's name, age, gender, etc.
The patient's name, age and sex. p>
Parameter Measurement, Calculation and Display:SOS, BUA, BQI, T-Score, Z-Score, T-Ratio,Z-Ratio
Check Confirmation:Daily Test Function
Report Output:Display, Storage, Setting, Preview, Printing
Main Unit
Dimensions:497mm x 279mm x 210mm (OSTEOKJ2000 model)
645mm x 330mm x 360mm (OSTEOKJ3000, OSTEOKJ3000+ models)
Weight:7.9kg (OSTEOKJ2000 model)
13kg (OSTEOKJ3000, OSTEOKJ3000+)
Input voltage: Single-phase AC 220V±10%
Frequency: 50Hz
Input power: <200VA
Continuous working time: >8 hours
Liquid inlet protection: IPX0
Fuse: AC250V,3.15A<
Ultrasonic Probe
Center Frequency:0.5MHz±10%
-6db Wideband:>60%
Diameter:31.75mm
Excitation Voltage:200Vp-p, Pulse Width:1us
Inlet Protection:IPX7
Connector Type:Q9
Environmental Requirements
Operating Temperature:10 ～ 30 ℃
Transportation/Storage Temperature:-10 ～ 40 ℃
Operating Humidity:30 ～ 70% Relative Humidity
Transportation/Storage Humidity:Relative Humidity 0 ～ 80%, Non-condensing
Atmospheric Pressure:860 ～ 1060 hPa
Shock Wave: Do not exceed 2g in 6 microseconds
Environmental Hygiene: Install and use the device in a clean, ventilated, well-ventilated room, avoiding dust and fumes, and clean the instrument and cover it with a dust-proof cloth after each use.... >>
What are the precautions for bone density test?
Bone density test precautions: First, it is recommended not to test the bone density of people under 20 years of age. Second, it is recommended not to test the bone density of people who have a fracture of the legs or who have a joint replacement of the legs. Third, it is recommended not to test the bone density of people who have skin ulcers in the heels. Osteoporosis is a progressive disease that develops with age. Osteoporosis can be caused by old age, menopause in women and endocrine diseases. The prevalence of osteoporosis is 50% in people over 50 years of age, which makes them susceptible to fractures, most commonly in the neck of the femur, spine and radius-ulna. The mortality rate due to complications within 6 months after femoral neck fracture is more than 20%, which brings a heavy burden to families and society. Therefore, early diagnosis and treatment of osteoporosis can prevent the occurrence of fractures. Detailed information? Click here to consult an expert online Health experts suggest that osteoporosis rarely has self-conscious symptoms and is not easy to be detected at an early stage, therefore, it is recommended that each person should have a bone density screening test to understand their own bone condition. With its internationalized high-end service and quality, the website has won the recognition and praise from all walks of life, and has successively won the Top Ten Influential Brands of China's Health Management Service, China's Top Ten Brand Physical Examination Institutions, and the Best Model Brand of China's Physical Examination Industry, as well as being selected as the only designated physical examination institution for the Miss World City Contest in 2012. Moreover, the website of Healthy People has set up many health checkup packages for the general friends, which can carry out detailed checkups on friends' physical conditions and guarantee their health to the greatest extent possible. There are many packages that are suitable for you!