Currently, the best method for diagnosing osteoporosis is by a measurement of bone density in the spine and the hips using Dual Energy X-ray Absorptiometry (DEXA) scanner. This uses a very low dose of radiation and involves you lying on a firm couch whilst an x-ray arm passes over you; it does not involve you going into a "tunnel". It is a painless procedure, which takes about 10 minutes and it measures bone density in the lower spine and hips. These measurements give an overall prediction of your bone density and strength. Dexa scans are usually only done in those people at highest risk of osteoporosis and you have to be referred by a doctor.
Since osteoporosis is "silent" prior to a fracture occurring, anyone who thinks that they may be at risk of osteoporosis, should discuss with a doctor or nurse whether or not a DEXA scan is indicated; if osteoporosis is diagnosed, appropriate treatment can be prescribed which can reduce the risk of fracture.