Objective: Sonography is one of the most suitable tools for the evaluation of abdominal adiposity and the differential assessment of subcutaneous and visceral fat. Its accuracy has been validated by several studies. However, the reliability of sonography in the evaluation of abdominal adiposity remains a matter of debate, with values of inter- and intraoperator reproducibility varying significantly, depending on studies. This could result from different methodologic and technical variables; nevertheless, studies evaluating the influence of technical issues on sonographic measurement accuracy and reliability are almost completely missing. Our goal was to analyze how much patient breathing, abdominal distension, and the use of different equipment could modify the values of abdominal adiposity evaluated by sonography and to identify and to describe the technical protocol with the highest inter- and intraoperator reliability. Materials and Methods: We prospectively enrolled 30 patients (15 women, 15 men; mean age ± SD, 32.7 ± 4.2 years old; body mass index, 25.6 ± 2.1 kg/m2) divided into three groups of 10 patients (five women and five men). Seven main parameters representative of subcutaneous and visceral fat were independently measured by two expert radiologists. Patients of group A underwent sonography before and 45 min after a standardized lunch. Patients of group B underwent sonography during inspiration and 30 min later during expiration. Patients of group C were analyzed with two ultrasound machines of different generations. Data collected with different conditions were compared (?, ?2, Student t test). The Lin correlation coefficient (p) was used to assess reliability. Results: Intraabdominal fat and aortomesenteric thickness, two visceral fat indexes, showed important variations in group A and group B, (mean ?, 24.3% ± 22.9% and 28.5% ± 38.45%, respectively), with relevant statistical significance (p < 0.0001 and < 0.005). No significant variation was observed in group C, notwithstanding the large technologic gap between the two machines. Reliability was good to excellent for all considered indexes (p range, 0.75–0.98) and in all conditions, even if slightly better values were observed for intraabdominal fat during expiration and without abdominal distension (groups A and B). Conclusion: Our study results indicate a need for standardization of the methods used for the sonographic evaluation of abdominal adiposity. Our data showed that changes in the methods used could lead to a variation of up to 20% of values commonly taken as markers of visceral fat, leading to an unacceptable lack of reliability in sonographic measurements of abdominal adiposity.
G. Filonzi, F. Ponti, D. Diano, E. Salizzoni, G. Battista, A. Bazzocchi (2013). The Role of ultrasonography in the evaluation of visceral fat: analysis of technical and methodological issues.
The Role of ultrasonography in the evaluation of visceral fat: analysis of technical and methodological issues
SALIZZONI, EUGENIO;BATTISTA, GIUSEPPE;
2013
Abstract
Objective: Sonography is one of the most suitable tools for the evaluation of abdominal adiposity and the differential assessment of subcutaneous and visceral fat. Its accuracy has been validated by several studies. However, the reliability of sonography in the evaluation of abdominal adiposity remains a matter of debate, with values of inter- and intraoperator reproducibility varying significantly, depending on studies. This could result from different methodologic and technical variables; nevertheless, studies evaluating the influence of technical issues on sonographic measurement accuracy and reliability are almost completely missing. Our goal was to analyze how much patient breathing, abdominal distension, and the use of different equipment could modify the values of abdominal adiposity evaluated by sonography and to identify and to describe the technical protocol with the highest inter- and intraoperator reliability. Materials and Methods: We prospectively enrolled 30 patients (15 women, 15 men; mean age ± SD, 32.7 ± 4.2 years old; body mass index, 25.6 ± 2.1 kg/m2) divided into three groups of 10 patients (five women and five men). Seven main parameters representative of subcutaneous and visceral fat were independently measured by two expert radiologists. Patients of group A underwent sonography before and 45 min after a standardized lunch. Patients of group B underwent sonography during inspiration and 30 min later during expiration. Patients of group C were analyzed with two ultrasound machines of different generations. Data collected with different conditions were compared (?, ?2, Student t test). The Lin correlation coefficient (p) was used to assess reliability. Results: Intraabdominal fat and aortomesenteric thickness, two visceral fat indexes, showed important variations in group A and group B, (mean ?, 24.3% ± 22.9% and 28.5% ± 38.45%, respectively), with relevant statistical significance (p < 0.0001 and < 0.005). No significant variation was observed in group C, notwithstanding the large technologic gap between the two machines. Reliability was good to excellent for all considered indexes (p range, 0.75–0.98) and in all conditions, even if slightly better values were observed for intraabdominal fat during expiration and without abdominal distension (groups A and B). Conclusion: Our study results indicate a need for standardization of the methods used for the sonographic evaluation of abdominal adiposity. Our data showed that changes in the methods used could lead to a variation of up to 20% of values commonly taken as markers of visceral fat, leading to an unacceptable lack of reliability in sonographic measurements of abdominal adiposity.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
