Types of densitometry and results in osteoporosis
Osteoporosis is characterized by reduction of mineral density of bone tissue with simultaneous change of its number and microarchitecture. There is impaired bone strength and increased likelihood of fractures, often in the spinal column, at the connection of the forearm with the wrist and in the neck of the femur.
In the past 20 years, we developed highly sensitive equipment to conduct bone-density analysis, which allows us to determine the percentage thinning of bone tissue and identify when an emerging disease.
There is a densitometric classification methods:
- Isotope diagnostic method, which includes monophenol and the two-photon absorptiometry, and quantitative computed tomography.
- Ultrasonic method.
both groups of methods are based on transmission of x-rays or isotope from an external source through the bone tissue to the detector. The directed flux of x-rays (isotopes) falls on the interested region of the skeleton and of the detector at the fixed intensity transmitted through bone of the ray.
In densitometry in osteoporosis for analysis using the following indicators:
- Navy – the content of mineral elements in bones, g;
- ВМD – mineral bone density, g/cm2.
In memory of equipment for densitometry in osteoporosis laid the normal range of bone density in various parts of the human skeleton, which are determined by the age and sex and calculated in the analysis of studies of large populations.
Together with the above mentioned indicators for the analysis criteria are as follows:
- the Z-statistic is the percentage of the norm;
- criterion T is the percentage of maximum bone mass in people of the same age and sex groups. This figure is taken as fundamental in assessing the progression of osteoporosis and osteopenia according to who standards.
Osteopenia is a preclinical stage of osteoporosis. There are three stages of osteopenia:
- Actually osteopenia (osteoporosis is asymptomatic). It is characterized by the value of T in the range of -1 to -2.5. At this stage, the person needs preventive treatment and monitoring.
- osteoporosis average degree occurs when the value of T-scores from -2.5 to 2.5.
- Index to more than 2.5 indicates osteoporosis fracture and advanced stages of the disease.
Types of research
Monophony and monoenergetic bone densitometry enables the analysis of bone density in peripheral sites of the human skeleton (often these were the sites of radius).
Appliances for this analysis, a compact, highly sensitive. But they have a drawback – with their help it is impossible to determine bone density in the lumbar spine of the ridge and the proximal femoral sites, prevention of deformation which is the primary goal of treatment of the disease.
Two-photon and dual-energy densitometry opportunities more: with its help it is possible to examine bone density at peripheral sites of the skeleton (often checked the vertebrae of the lumbar spine, femoral neck, and radial bone and ward's triangle). Some devices have a function of determining mineral picture the entire skeleton.
X-ray densitometry is today more popular with professionals, because it does not require changing an expensive source of isotopes, has more resolution, allows the analysis faster and has less radiation exposure per person.
On the basis of ultrasound densitometry is a measurement of velocity of ultrasonic waves on the surface of the bone. With this analysis you can set the density, strength and elasticity of the investigated area of the skeleton.