DEXA Data Interpretation & Reporting — Questions and Answers

Question 1: What does a T-score represent?

Daily bone change
Fat percentage
Comparison to young adult average (Correct answer)
Calcium intake

Correct answer: Comparison to young adult average

A T-score in DEXA scanning compares a patient's Bone Mineral Density (BMD) to the average BMD of a healthy young adult of the same sex at peak bone mass. This score is used to diagnose osteoporosis or osteopenia in postmenopausal women and men over 50. It helps assess the risk of fractures based on bone density relative to a healthy reference population.

Question 2: What does a Z-score compare?

Fat mass
Bone density of age-matched peers (Correct answer)
Water weight
Daily height changes

Correct answer: Bone density of age-matched peers

A Z-score in DEXA scanning compares a patient's Bone Mineral Density (BMD) to the average BMD of individuals of the same age, sex, and ethnic background. This score is primarily used for children, premenopausal women, and men under 50 to determine if their bone density is lower than expected for their age, helping identify secondary causes of low bone mass.

Question 3: What T-score indicates osteoporosis?

Above -1.0
Between -1 and -2.5
Below -2.5 (Correct answer)
Zero

Correct answer: Below -2.5

According to the World Health Organization (WHO) criteria, a T-score of -2.5 or lower indicates osteoporosis. This signifies significantly reduced bone mineral density, placing the individual at a high risk for fragility fractures. T-scores between -1.0 and -2.5 indicate osteopenia, or low bone mass.

Question 4: What should be included in a DEXA report?

Patient opinion
Only numerical data
Insurance status
BMD, scan site, interpretation (Correct answer)

Correct answer: BMD, scan site, interpretation

A comprehensive DEXA report should include the measured Bone Mineral Density (BMD) values for all scanned sites (e.g., lumbar spine, hip), along with the corresponding T-scores and Z-scores. Crucially, it must also contain a clear interpretation of these findings by a qualified physician, including diagnostic classification and recommendations.

Question 5: Why is follow-up recommended?

Track weight loss
Assess pain levels
Monitor changes over time (Correct answer)
Compare technician skills

Correct answer: Monitor changes over time

Follow-up DEXA scans are recommended to monitor changes in bone mineral density over time, especially for patients diagnosed with osteopenia or osteoporosis, or those undergoing treatment. These scans allow healthcare providers to assess the effectiveness of interventions, track disease progression, and adjust treatment plans as needed to prevent fractures.

Question 6: What does a positive T-score suggest?

Bone damage
Low calcium
Higher than average BMD (Correct answer)
Radiation exposure

Correct answer: Higher than average BMD

A positive T-score suggests that a patient's bone mineral density (BMD) is higher than the average BMD of a healthy young adult at peak bone mass. While less common, it indicates robust bone health and a lower risk of osteoporosis.

Question 7: What can affect interpretation accuracy?

Room color
Technician name
Artifacts and positioning (Correct answer)
Patient mood

Correct answer: Artifacts and positioning

The accuracy of DEXA scan interpretation can be significantly affected by artifacts and improper patient positioning. Artifacts, such as metal objects or previous medical procedures, can obscure bone structures or create false readings. Incorrect positioning can lead to inaccurate region-of-interest selection and skewed BMD measurements, compromising the reliability of the diagnosis.

Question 8: What tool assists with scan interpretation?

Google Docs
Scan printer
Reporting software (Correct answer)
Ultrasound scanner

Correct answer: Reporting software

Specialized reporting software is an essential tool that assists with DEXA scan interpretation. This software processes the raw scan data, calculates BMD values, T-scores, and Z-scores, and often provides visual representations of bone density. It helps radiologists and clinicians efficiently analyze results and generate comprehensive patient reports.

Question 9: Who finalizes and signs the DEXA report?

Technician
Patient
Receptionist
Radiologist (Correct answer)

Correct answer: Radiologist

The radiologist is the medical professional responsible for reviewing, interpreting, finalizing, and signing the DEXA report. They possess the specialized training and expertise to accurately diagnose bone conditions based on the scan data and patient history, ensuring the report is clinically sound and actionable.

DEXA Data Interpretation & Reporting

What does a T-score represent?