New bioimpedance model accurately predicts lower limb muscle volume: validation by magnetic resonance imaging.
Am J Physiol Endocrinol Metab
; 282(4): E960-6, 2002 Apr.
Article
in En
| MEDLINE
| ID: mdl-11882519
ABSTRACT
Conventional bioimpedance analysis (BIA) methods now simplify the representation of lower limb geometry and electrical properties for body composition estimation. In the present study, a three-dimensional model of the lower limb was assembled by segmentation of magnetic resonance cross-sectional images (MRI) for adipose tissue, skeletal muscle, and bone. An electrical network was then associated with this model. BIA and MRI measurements were made in six lean subjects (3 men and 3 women, age 32.2 +/- 6.9 yr). Assuming 0.85 S/m for the longitudinal conductivity of the muscle, the model predicted in the examined subjects an impedance profile that conformed well to the BIA impedance profile; predicted and measured resistances were similar (261.3 +/- 7.7 vs. 249 +/- 9 Omega; P = not significant). The resistance profile provided, through a simpler model, muscle area estimates along the lower limb and total leg muscle volume (mean 4,534 cm(3) for men and 4,071 cm(3) for women) with a mean of the absolute value of relative error with respect to MRI of 6.2 +/- 3.9. The new approach suggests that BIA can reasonably estimate the distribution and volume of muscles in the lower extremities of lean subjects.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Magnetic Resonance Imaging
/
Electric Impedance
/
Muscle, Skeletal
/
Leg
Type of study:
Prognostic_studies
/
Risk_factors_studies
Limits:
Adult
/
Female
/
Humans
/
Male
Language:
En
Journal:
Am J Physiol Endocrinol Metab
Journal subject:
ENDOCRINOLOGIA
/
FISIOLOGIA
/
METABOLISMO
Year:
2002
Document type:
Article
Affiliation country: