Search results
Results from the WOW.Com Content Network
In educational assessment, T-score is a standard score Z shifted and scaled to have a mean of 50 and a standard deviation of 10. [ 14 ] [ 15 ] [ 16 ] In bone density measurements, the T-score is the standard score of the measurement compared to the population of healthy 30-year-old adults, and has the usual mean of 0 and standard deviation of 1.
A scanner used to measure bone density using dual energy X-ray absorptiometry. Bone density, or bone mineral density, is the amount of bone mineral in bone tissue.The concept is of mass of mineral per volume of bone (relating to density in the physics sense), although clinically it is measured by proxy according to optical density per square centimetre of bone surface upon imaging. [1]
Since probability tables cannot be printed for every normal distribution, as there are an infinite variety of normal distributions, it is common practice to convert a normal to a standard normal (known as a z-score) and then use the standard normal table to find probabilities. [2]
At the hip, a DXA-equivalent T-score may be calculated for comparison to the WHO classification at the proximal femur as normal, osteopenia (T-Score < -1.0 and > -2.5) or osteoporosis (T-Score < -2.5). [17] This T-Score may also be used for fracture risk probability calculation in the WHO FRAX tool [18] with "T-Score" as the appropriate DXA ...
where z is the standard score or "z-score", i.e. z is how many standard deviations above the mean the raw score is (z is negative if the raw score is below the mean). The reason for the choice of the number 21.06 is to bring about the following result: If the scores are normally distributed (i.e. they follow the "bell-shaped curve") then
Information from the DXA scanner creates a bone mineral density T-score by comparing a patient's density to the bone density of a healthy young person. Bone density between 1 and 2.5 standard deviations below the reference, or a T-score between −1.0 and −2.5, indicates osteopenia (a T-score smaller than or equal to −2.5 indicates ...
The US National Osteoporosis Foundation recommends pharmacologic treatment for patients with hip or spine fracture thought to be related to osteoporosis, those with BMD 2.5 SD or more below the young normal mean (T-score -2.5 or below), and those with BMD between 1 and 2.5 SD below normal mean whose 10-year risk, using FRAX, for hip fracture is ...
The World Health Organization (WHO) has established a diagnostic criteria for osteoporosis using BMD T-scores which describes an individual's BMD in terms of the number of SDs by which is differs from the mean peak value in young, healthy persons of the same sex—currently more than 2.5 SDs below the mean as the criterion for osteoporosis. [5]