DEXA and Secondary Osteoporosis (1).docx

**DEXA and Secondary Osteoporosis** DEXA stands for Dual-Energy X-ray Absorptiometry. It is a widely used technique to measure bone mineral density (BMD). DEXA scans are primarily used to diagnose osteoporosis and assess fracture risk by measuring the amount of mineral (such as calcium) in bones, u...

**DEXA and Secondary Osteoporosis** DEXA stands for Dual-Energy X-ray Absorptiometry. It is a widely used technique to measure bone mineral density (BMD). DEXA scans are primarily used to diagnose osteoporosis and assess fracture risk by measuring the amount of mineral (such as calcium) in bones, usually at the hip and spine. It involves low-dose X-rays and is considered a safe and non-invasive procedure. DEXA scans provide T-scores and Z-scores that compare a person\'s BMD to that of a healthy young adult (T-score) or to age-matched peers (Z-score). **Interpreting DEXA Scores** **T Score** - Compares patient\'s bone density to that of a healthy young adult. - More negative T Score indicates higher fracture risk. **Z Score** - Compares patient\'s bone density to that of same-sex, age-matched peers. - Z Score \< -2.0 requires evaluation for secondary osteoporosis. **FRAX Score** - WHO Fracture Risk Assessment Tool. - Considers age, sex, weight, height, previous fractures, parental hip fracture, smoking, glucocorticoid use, rheumatoid arthritis, alcohol, and bone density. **Alternative Imaging Modalities** - Whole body DEXA, quantitative CT, ultrasound of calcaneus. - Less likely exam topics but used for specialized cases. **Screening for Secondary Osteoporosis** - Causes include hyperparathyroidism, chronic kidney disease, multiple myeloma, leukemia, lymphoma, hyperthyroidism. **Biochemical Markers for Bone Turnover** - Indicate bone repair, damage, and micro-fractures. - Includes serum C-telopeptide (CTX), urinary N-telopeptide (NTX), alkaline phosphatase, osteocalcin. **Role of Biochemical Markers** - Aid in fracture risk prediction independent of bone density. - Assess therapy response within months of initiation. - Recommended for patients with borderline bone density or starting pharmacological therapy. **Practical Considerations** - Markers may not be covered by insurance. - Important for monitoring treatment response and patient compliance. \_\_\_\_\_\_ Which of the following scores represents the standard deviation between the patient\'s score and the average peak young adult bone mass? - T score Which of the following is NOT a part of the FRAX questionnaire (WHO fracture risk assessment tool)? - Biochemical marker of bone resorption Which of the following is an example of a biochemical marker for bone remodeling? - Serum C-telopeptide (Explanation: Serum C-telopeptide is a more direct marker of bone resorption, while osteocalcin reflects overall bone formation and turnover, making C-telopeptide more useful in assessing conditions like osteoporosis.)