Intra-Abdominal Adipose Tissue Quantification by Alternative Versus Reference Methods: A Systematic Review and...

Area of Science:

• Medical Imaging
• Body Composition Analysis
• Metabolic Health

Background:

• Accurate quantification of intra-abdominal adipose tissue (IAAT) is crucial for assessing metabolic disease risk.
• Computed tomography (CT) and magnetic resonance imaging (MRI) are reference standards for IAAT measurement but are costly and have limited accessibility.
• Alternative methods for IAAT assessment are needed for broader clinical and research applications.

Purpose of the Study:

• To evaluate the agreement between IAAT measurements obtained by alternative methods (ultrasound, bioelectrical impedance analysis, dual-energy x-ray absorptiometry) and the reference standards (CT and MRI).

Main Methods:

• A systematic literature search of MEDLINE and EMBASE was conducted to identify relevant studies.
• A meta-analysis using a random-effects model was performed to pool mean differences and 95% limits of agreement (LoA) between methods.
• Twenty-four studies employing four comparator methods for IAAT quantification were included.

Main Results:

• Ultrasound showed a pooled mean difference of -0.3 cm with wide LoA (-3.4 to 3.2 cm).
• Bioelectrical impedance analysis demonstrated a mean difference of -11.6 cm² (LoA: -43.1 to 19.9 cm²), indicating systematic underestimation.
• Dual-energy x-ray absorptiometry (DXA) yielded mean differences of 8.1 cm² (LoA: -98.9 to 115.1 cm²) for area and 10 cm³ (LoA: -280 to 300 cm³) for volume.

Conclusions:

• Ultrasound and DXA exhibit minimal bias when measuring IAAT compared to CT or MRI.
• Bioelectrical impedance analysis systematically underestimates IAAT.
• The broad limits of agreement for most comparator methods, except DXA for IAAT volume, necessitate further optimization for reliable clinical and research use.