DEXA Body Composition Analysis & DXA Clinical Applications 3

Question 1

Which reference database should be used when generating Z-scores for DXA body composition parameters in a 30-year-old female patient?

Accepted Answer

An age- and sex-matched reference population (Z-score)

Answer

Z-scores for body composition compare the patient to an age- and sex-matched normative population, which is the appropriate reference for adults of all ages.

Question 2

A DXA report shows an Android/Gynoid (A/G) fat ratio of 1.4 in a 55-year-old male patient. This finding is clinically significant because:

Accepted Answer

An elevated A/G ratio is associated with increased cardiovascular and metabolic disease risk

Answer

An elevated A/G ratio indicates disproportionate central (abdominal) fat accumulation relative to peripheral fat, a pattern strongly associated with insulin resistance, dyslipidemia, and cardiovascular disease.

Question 3

For DXA body composition scans, recent food intake can affect results primarily by:

Accepted Answer

Increasing soft tissue hydration and transiently inflating lean mass measurements

Answer

A recent large meal increases gastrointestinal contents and fluid shifts, which DXA may misclassify as lean mass, slightly inflating that compartment; patients are typically asked to fast for 3 hours prior.

Question 4

The EWGSOP2 (European Working Group on Sarcopenia in Older People) recommends which DXA-based cutoff for low appendicular lean mass index (ALM/ht²) in men?

Accepted Answer

Less than 7.0 kg/m²

Answer

EWGSOP2 recommends an ALM/ht² cutoff of < 7.0 kg/m² in men and < 5.5 kg/m² in women to define low muscle mass as part of the sarcopenia diagnosis.

Question 5

When a metal implant is present in a patient's hip, the recommended approach for a DXA body composition whole-body scan is to:

Accepted Answer

Exclude the implant region from the analysis using the manufacturer's exclusion software tool

Answer

Most DXA software provides a tool to exclude or flag regions containing metal implants so that the remaining body composition data remain valid and the implant artifact does not propagate.

(DEXA) DEXA Bone Density Scan Certification Practice Test

(DEXA) DEXA Bone Density Scan Certification Practice Test

DEXA Body Composition Analysis & DXA Clinical Applications 3