Due to differences in principle, performance and radiation, ultrasonic bone densitometers and dual-energy X-ray bone densitometers (DXA) each have clear target audiences, as follows:
I. Applicable Population of Ultrasonic Bone Density Meter
The ultrasonic bone densitometer, with its core advantages of “no radiation and convenient operation”, is more suitable for screening, special sensitive groups and non-diagnostic assessment scenarios, specifically including
Large-scale screening of the population
Community/unit physical examination population: It is used for the preliminary assessment of bone health in general adults and for the rapid screening of high-risk individuals with abnormal bone mass (such as routine bone density screening for people over 40 years old).
School children and adolescents: Assess the bone development of children, no radiation risk, suitable for long-term follow-up (such as regular monitoring of children with delayed growth and development).
Nursing home/elderly community population: Preliminary prediction of fracture risk for the elderly does not require complex equipment conditions and can complete the detection in batches.
People who are sensitive to or contraindicated to radiation
Pregnant women: During pregnancy (especially in the middle and late stages of pregnancy), it is necessary to monitor changes in bone density (such as bone loss related to pregnancy). Radiation has no effect on the fetus.
Lactating women: Avoiding the potential interference of radiation on lactation can safely assess postpartum bone health.
Children and adolescents: In addition to bone development assessment, it can be used as a long-term monitoring tool for children with malnutrition, endocrine diseases (such as thyroid dysfunction), and other conditions that affect bone health (radiation exposure should be avoided).
Those who are resistant to radiation or have limited detection conditions
People who refuse X-ray examination due to psychological factors: For instance, those who have a strong fear of radiation can undergo a preliminary assessment through ultrasound.
Primary medical institutions/mobile testing scenarios: The equipment is portable (some models are handheld or small desktop), suitable for resource-limited scenarios such as rural hospitals and community health service centers, and is used for basic bone health screening.
Ii. Applicable Population for Dual-energy X-ray Bone Densitometer (DXA)
DXA, with its core values of “high accuracy and quantitative diagnosis”, is the “gold standard” for the diagnosis of osteoporosis, precise assessment of fracture risk and treatment monitoring. Its applicable population is mainly concentrated in scenarios where “a clear diagnosis or precise assessment is required”, specifically including
Those suspected of having osteoporosis or abnormal bone mass and requiring a confirmed diagnosis
Postmenopausal women: The decline in estrogen levels after menopause is a high-risk factor for osteoporosis. It is necessary to test bone density through DXA to determine whether the diagnostic criteria for osteoporosis are met (T value ≤-2.5SD).
Middle-aged and elderly men: With age, bone mass loss accelerates. It is necessary to confirm whether there is bone mass reduction or osteoporosis through DXA.
For those with a history of fragility fractures: If fractures of the vertebral body, hip, etc. occur without obvious trauma (or minor trauma), the degree of bone density reduction should be determined through DXA to determine whether it is an osteoporotic fracture.
High-risk groups for osteoporosis
For those who have been taking drugs that affect bone metabolism for a long time: such as those who have been taking glucocorticoids (such as prednisone), antiepileptic drugs, etc. for a long time (≥3 months), bone density changes should be monitored regularly (every 1-2 years) through DXA.
Patients with endocrine/metabolic diseases: such as hyperparathyroidism, diabetes, rheumatoid arthritis, etc. These diseases may lead to bone mass loss and require precise assessment of bone health status by DXA.
Other high-risk factor groups: such as those with a thin build (BMI < 19kg/m²), long-term smoking/heavy drinking, severe calcium/vitamin D deficiency, and prolonged sitting, etc., need to determine the fracture risk level through DXA.
Monitors during osteoporosis treatment
Patients who have been diagnosed with osteoporosis and are receiving drug treatment (such as bisphosphonates, calcitonin, etc.) need to have their bone density rechecked by DXA every 1-2 years to evaluate the treatment effect (such as whether bone density has increased and whether T value has improved), so as to adjust the treatment plan.
Those who need a precise assessment of the risk of fractures
When it is necessary to clarify the risk of fractures in clinical practice (such as preoperative assessment and surgical risk stratification for elderly patients), quantitative indicators such as T value and Z value should be obtained through DXA, and a comprehensive judgment should be made in combination with age, medical history, etc. (for example, the FRAX score should be based on DXA bone mineral density).
Ultrasonic bone densitometer: Its core features are “radiation-free and wide coverage”, making it suitable for screening, children/pregnant women and other sensitive groups, as well as grassroots/mobile testing scenarios. However, it cannot be used as a basis for diagnosis.
DXA: Its core lies in “precise diagnosis and quantitative assessment”. It is suitable for those suspected of having osteoporosis and requiring a confirmed diagnosis, as well as for risk assessment and treatment monitoring in high-risk groups. It is the “gold standard” for clinical decision-making.
In clinical practice, high-risk groups are often screened out by ultrasound first, and then DXA is used to confirm the abnormal individuals, taking into account both efficiency and accuracy.
Post time: Aug-22-2025