Norland Elite 437A150, Operator'S Manual

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WHO Criteria
The WHO criteria indicates that patients having T-Scores from +1 to -1 are considered to have normal bone
density. Patients having T-Scores between -1 and -2.5 are considered osteopenic (low in bone mass) and at an
increased risk of fracture. Patients having T-Scores below -2.5 are considered osteoporotic and have a high risk
of fracture.
For detailed information regarding WHO criteria, please obtain a copy of the WHO Technical Report Number
843, entitled “Assessment of Fracture Risk and its Application to Screening for Postmenopausal Osteo-
porosis”. It was published in 1994 by the World Health Organization, Geneva, Switzerland.
Norland Fracture Risk
Printed reports from all Norland scanners contain a graph plotting the BMD of the current scan against Fracture
Risk information, based on the WHO criteria. An example of the graph is shown below. The appearance of the
graph on any report may vary, based on the presence of Age-matched values or color versus black and white
reports.
Figure 18-1: Fracture Risk Reference Set Chart (sample)
Low Risk
(Green)
Medium Risk
(Yellow)
High Risk
(Red)
The upper area, labeled “Low Risk”, represents the range of values termed by WHO to be “normal” - having
adequate bone mineral. This is the region with T-Score values above minus 1 standard deviation, referenced to
the young adult mean BMD value found in the reference population.
The middle area, labeled “Medium Risk”, represents the range of values termed by WHO to be “osteopenic” -
having reduced bone mineral. The BMD T-Score values in this region range between minus 1 standard devi-
ation and minus 2.5 standard deviations. A patient whose value is plotted in this region may be susceptible to
fracture.
The lower area, labeled “High Risk”, represents the range of values termed by WHO to be “osteoporotic” - hav-
ing severely reduced bone mineral. The BMD T-Score values in this region are more than 2.5 standard devi-
ations below the young adult mean value. A patient whose value is plotted in this region has a high spontaneous
fracture probability.
Operator's Guide
437D140 Rev. I
18-6 Reference Data Sets