Table 1.

Strengths and weakness of measuring muscle mass by dual energy X‐ray absorptiometry

Strengths	Weaknesses
Non‐invasive with small doses of radiation (<1 μSv for whole‐body scans).41	Projectional technique, individual muscles cannot be assessed separately.
Relatively cheap, compared with CT scan or MRI.	Not portable, which may preclude its use in large‐scale epidemiological studies and studies in the home setting.
Rapid	Availability is limited in some care settings.
Allows measurement of three body compartments.	Body thickness and abnormalities in hydration status (e.g. water retention, heart, kidney, or liver failure) can affect muscle mass measure.42
Low precision errors	Very tall and very obese people cannot be measured.
	Cannot quantify fatty infiltration of muscle. It is a bias in the diagnosis of sarcopenia obesity.
	Does not measure skeletal muscle mass in non‐limb regions of the body (e.g. trunk).
	Several devices and several software packages and software versions resulting in different results.

CT, computed tomography; MRI, magnetic resonance imaging.