Is digital image plethysmographic (DIP) acquisition a valid new tool for preoperative body composition assessment? A validation by dual-energy X-ray absorptiometry

Obes Surg. 2006 May;16(5):560-6. doi: 10.1381/096089206776945011.


Background: The increasing incidence of obesity and the wider acceptance of laparoscopic surgery, have lead to a 10-fold increase in bariatric operations in the last 10 years. Widely used indices of obesity (weight and body mass index - BMI) cannot adequately distinguish between fat mass (FM), represented by the sum of kilograms (kg) of lipid, and fat-free mass (FFM), inclusive of lean (kg of proteins), bone (kg of minerals), glycogen, and total body water (TBW), which are important parameters for clinical and physiological studies.

Methods: Anthropometric variables were measured in 19 Caucasian Italian individuals according to standard methods. Body weight (kg) and height (m) were measured, and BMI was calculated as kg/m(2). Body composition was evaluated, with a mean BMI of 25.95+/-5.04 kg/m(2), by dual X-ray absorptiometry (DXA) and by digital image plethysmographic (DIP) acquisition with a digital camera. The clear-colored body of the subjects was automatically converted into a front and lateral red-shaped figure, and then through algorithms the 2 pictures were transformed into a nominal volume; body weight was then divided by the estimated volume, so that the body density could be obtained. DXA was used as a comparison to assess fat mass and fat-free mass. Radiation exposure was <0.6 mSv.

Results: Significant positive correlation (R= 0.971, P<0.001) was found between data of body composition obtained by DXA and DIP.

Conclusions: Body volume assessed using DIP or DXA did not differ. According to this validation study, DIP represents a new promising tool for clinical applications.

Publication types

  • Validation Study

MeSH terms

  • Absorptiometry, Photon*
  • Adult
  • Body Composition*
  • Female
  • Humans
  • Image Processing, Computer-Assisted*
  • Male
  • Middle Aged
  • Plethysmography / methods*