What tests are used to detect a problem with bone?

Usually, bone problems are detected by measuring bone density (mass) using special types of X-rays. Bone problems can also be detected by ultrasound scans that use high-frequency sound waves.

Bone markers are tests that detect products of bone resorption and formation. They are signs of the bone turnover process and are sometimes used as an aid to bone density testing when doctors are evaluating whether or not you have a bone disease.

Bone resorption urine or blood tests include:

• C-telopeptide (C-terminal telopeptide of type 1 collagen (CTx)) – a fragment of the protein matrix
• N-telopeptide (N-terminal telopeptide of type 1 collagen (NTx)) – another fragment of the protein matrix
• Deoxypyridinoline (DPD) - a collagen breakdown product with a ring structure
• Pyridinium Crosslinks - a group of collagen breakdown products that includes DPD

Bone formation blood tests include:

• Bone-specific alkaline phosphatase (ALP) – one of the isoenzymes (types) of ALP; it is associated with osteoblasts and thought to have a role in bone mineralization
• Osteocalcin (bone gla protein) – a protein created by osteoblasts; part of the non-collagen portion of the new bone structure; some of it also enters the bloodstream

One or more of these tests may be ordered to help identify patients with increased bone resorption and/or formation rates. Bone markers are used to monitor therapy for bone disease and to help your doctor determine if your body is responding to treatment. They can enable your doctor to tell if you are responding to anti-resorption or bone formation therapies in a much shorter time period than the X-ray types of bone density testing (three to six months versus 1 to 2 years). This way, your therapy can be altered if you are not responding properly to it.

There is also some evidence that bone markers can help doctors to predict which breast and prostate cancer patients are at high risk for bone metastases. Bone markers may also be able to predict a patient’s response to therapy for a bone-loss condition.