Bone density test results
- A T-score within 1 SD (+1 or -1) of the young adult mean indicates normal bone density.
- A T-score of 1 to 2.5 SD below the young adult mean (-1 to -2.5 SD) indicates low bone mass.
- A T-score of 2.5 SD or more below the young adult mean (more than -2.5 SD) indicates the presence of osteoporosis.
DXA Scan Results
T-score of -1.0 or above = normal bone density. T-score between -1.0 and -2.5 = low bone density, or osteopenia. T-score of -2.5 or lower = osteoporosis.
Because cancer cells multiply rapidly, they will appear as a hot spot on a bone scan. This is due to the increased bone metabolism and bone repair in the area of the cancer cells. Bone scans may also be used to stage the cancer before and after treatment in order to assess the effectiveness of the treatment.
A T-score between −1 and −2.5 indicates that you have low bone mass, although not low enough to be diagnosed with osteoporosis . A T-score of −2.5 or lower indicates that you have osteoporosis. The greater the negative number, the more severe the osteoporosis.
A T-score of -1.0 or above is normal bone density. Examples are 0.9, 0 and -0.9. A T-score between -1.0 and -2.5 means you have low bone mass or osteopenia. Examples are T-scores of -1.1, -1.6 and -2.4.
The lower your score, the weaker your bones are: T-score of -1.0 or above = normal bone density. T-score between -1.0 and -2.5 = low bone density, or osteopenia. T-score of -2.5 or lower = osteoporosi
The lower the T-score, the lower the bone density:
- A score of –1.0 to +1.0 means you have normal bone density.
- A score between –1.0 to –2.5 means you have low bone density (osteopenia).
- A score of –2.5 or below means you have osteoporosis.
Severe (established) osteoporosis is defined as having a bone density that is more than 2.5 SD below the young adult mean with one or more past fractures due to osteoporosis. Secondly, your BMD is compared to an age-matched norm. This is called your Z-score.
An abnormal scan will show "hot spots" and/or "cold spots" as compared to surrounding bone . Hot spots are areas where there is an increased collection of the radioactive material. Cold spots are areas that have taken up less of the radioactive material.
Using a bone scan when cancer is suspected can be particularly helpful because the scan can find both primary cancer—or, cancer that started in your bones—and bone metastases, which is cancer that has spread to the bones from another part of your body.
In an adult, dark spots usually indicate that there is a problem with the skeleton . The increased bone-making activity that the dark spots represent is the skeleton's response to the problem. For example, if there is a bone fracture, bone cells will very quickly begin to make new bone to try to repair it.
Many changes that show up on a bone scan are not cancer. With arthritis, the radioactive material tends to show up on the bone surfaces of joints, not inside the bone. But it can be hard to tell the difference between arthritis and cancer — especially in the spine.
A T score of -1 to +1 is considered normal bone density. A T score of -1 to -2.5 indicates osteopenia (low bone density). A T score of -2.5 or lower is bone density low enough to be categorized as osteoporosis.
T-scores versus Z-scores
|-1.0 or higher||normal|
|-1.0 to -2.5||osteopenia, which indicates that the bone mass is low but not low enough to classify as osteoporosis|
|-2.5 or below||osteoporosis|
Bone Mass. Bone content is the percentage of bone mineral as compared to total body weight. The average bone content for adults is 3-5% . This measurement is good to keep track over a long period of time as bone mass can decline slowly with ag