Question 1
A 42-year-old premenopausal female with newly diagnosed celiac disease undergoes bone density testing to evaluate for malabsorption-related bone loss. The radiology report includes both T-scores and Z-scores. Which approach is most appropriate?
▸ Why A is the answer
When interpreting bone density scans, the choice between T-scores and Z-scores depends on the patient's age and menopausal status. T-scores compare the patient's bone density to a healthy 30-year-old adult, while Z-scores compare it to age-matched peers. Option A is correct because the Z-score is the appropriate metric for premenopausal women, men under 50, and children. A Z-score of -2.0 or lower is defined as "below expected range for age." Options B and D are incorrect because T-scores are reserved for postmenopausal women and men aged 50 and older; using them in a 42-year-old premenopausal woman can lead to overdiagnosis. Option C is incorrect because the FRAX tool is not validated for use in premenopausal women and should not be used to estimate fracture risk in this population.
🔑 Key takeaway
Z-scores, rather than T-scores, must be used to evaluate bone mineral density in premenopausal women.
