Table 5 Impact of CT measurement location on adipose tissue assessment

L3 Vertebra

Pekar et al. (n = 866)

McInerney et al. (n = 3174)

Somaschini et al. (n = 168)

Guler et al. (n = 258)

Mok et al. (n = 460)

Van Erck et al. (n = 1404)

• Strong correlation with whole-body composition

• Most validated in research

• Consistent landmarks

• Less affected by bowel content

• Requires specific reconstruction of pre-TAVI CT

• May not be included in all acquisition protocols

• Most accurate reflection of total body adiposity

• Better reproducibility across studies

• Recommended as standard location for adipose tissue assessment

• Should be included in all TAVI planning protocols

L4 Vertebra

Foldyna et al. (n = 403)

• Slightly higher VAT content than L3

• Clear anatomical landmarks

• Less validated than L3

• May overestimate VAT relative to total body

• May show stronger VAT associations

• Less comparable to L3-based studies

• Can be used if L3 unavailable

• Results should note measurement level

L4/L5 Junction

Mancio et al. (n = 170)

• Historically used in early obesity research

• Maximum VAT area in many patients

• Variable relationship to total body composition

• Less reproducible positioning

• Affected by pelvic anatomy

• Typically shows highest VAT:SAT ratio

• May overemphasize VAT significance

• Not recommended for standardization

• Less reliable for comparison across studies

Umbilical Level

Shibata et al. (n = 1372)

Higuchi et al. (n = 234)

Okuno et al. (n = 100)

• Easily identifiable external landmark

• Can be used with limited scan ranges

• Variable relationship to vertebral levels

• Affected by abdominal wall laxity

• Less consistent in obese patients

• More variable measurements

• Greater potential for misclassification

• May show different associations with outcomes

• Not recommended as primary measurement location

• Should specify vertebral level when using umbilical slices

Whole Abdominal Volume

Limited use

• Most comprehensive assessment

• Not affected by single-slice variability

• Time-consuming analysis

• Requires specialized software

• No standardized protocols

• May be more sensitive but less specific

• Difficult to compare across studies

• Valuable for research but impractical for routine use

• Beneficial as validation for single-slice metrics