Scans and heart tests
DEXA bone density results: T-score and Z-score explained
A bone density report gives a table of numbers for each site scanned, usually the lower spine and the hip, with two different scores for each. Add your report below to see which score is which and what the report concludes.
Explain your bone density report
- 1. Add itDrop a PDF, take a photo or paste the text.
- 2. Check itPersonal details are removed on your device. You approve what is sent.
- 3. Read itSummary, table of results, terms and questions to ask.
The explainer opens on its own page with no adverts and no outside scripts. Your file is read on your device and is never uploaded.
What you get
- Each scanned site on its own row with its BMD, T-score and Z-score.
- The difference between a T-score and a Z-score explained.
- The category your report states for each site, in its own words.
- Questions to ask about what the result means for you.
What the report contains
- BMDBone mineral density, in grams per square centimetre
- T-scoreYour BMD compared with that of a healthy young adult
- Z-scoreYour BMD compared with people of your own age and sex
- SitesLumbar spine (L1 to L4), total hip and femoral neck, sometimes the forearm
- FRAXAn estimate of the chance of a fracture over the next ten years
- Change since previous scanWhether BMD has moved by more than the scanner's margin of error
What this tool cannot tell you
The scores are one input into a judgement about fracture risk, alongside age, previous fractures, medicines and other conditions. Different sites often give different scores. MedicDecode restates the numbers and the category your report gives. It does not diagnose osteoporosis or advise on treatment.
Common questions
What is a normal Z-score for bone density?
A Z-score compares you with people of your own age and sex. Scores above -2.0 are generally called within the expected range for age; -2.0 or lower is below it.
What is the difference between a T-score and a Z-score?
A T-score compares your bone density with a healthy young adult; a Z-score compares it with people your age. Reports for older adults are usually read by the T-score.
What do the T-score categories mean?
Under the standard categories, -1.0 and above is normal, between -1.0 and -2.5 is low bone mass (osteopenia), and -2.5 or lower is in the osteoporosis range.
Which matters more, the T-score or the Z-score?
Reports generally use the T-score for postmenopausal women and men over 50, and the Z-score for younger adults and children. Your report's conclusion will say which it relied on.
Why are my scores different at the spine and the hip?
Bone density is not the same throughout the skeleton, so it is normal for sites to differ.
What is a FRAX score?
It is a calculated estimate of fracture probability over ten years, based on bone density and other risk factors. Not every report includes it.
Words you may see on this report
Tap a word for its plain-English meaning, an example line and what it does not mean.
- Atelectasis
Atelectasis means part of a lung is not fully expanded, so the small air sacs there are partly or completely deflated.
- BI-RADS
BI-RADS is a scoring system from 0 to 6 used on mammogram, breast ultrasound and breast MRI reports to describe findings and next steps.
- Cardiomegaly
Cardiomegaly means the heart looks larger than expected, usually on a chest X-ray, and it is a description rather than a diagnosis.
- Clinical correlation
Clinical correlation means the radiologist is asking your doctor to compare the scan with your symptoms, examination and other tests.
- Consolidation
Consolidation on a chest scan means part of the lung that is normally filled with air is filled with something else, such as fluid or pus.
- Contrast
Contrast is a dye given before or during a scan to make blood vessels and certain tissues show up more clearly.
- Cyst
A cyst is a closed sac with a thin wall that usually holds fluid, and simple cysts seen on scans are very common and usually harmless.
- Degenerative changes
Degenerative changes means wear-and-tear changes in joints or the spine that commonly happen with age and use.
- Disc bulge
A disc bulge means a spinal disc extends a little beyond its normal edge, usually evenly around a wide area. It is very common.
- Effusion
An effusion is extra fluid that has collected in a space in the body, such as around the lungs, in a joint or around the heart.
- Ejection fraction
Ejection fraction is the percentage of blood the heart's main pumping chamber pushes out with each beat. It is one measure of heart pumping.
- Enhancement
Enhancement means an area becomes brighter on a scan after contrast dye is given, which shows it has a blood supply.
Medicines connected to this test
Their official labels mention this kind of test. Each is explained in plain English.
- Alendronate
a bisphosphonate, a medicine that slows the breakdown of bone by blocking cells called osteoclasts