Ultrasonography Technique in Abdominal Subcutaneous Adipose Tissue Measurement: A Systematic Review

Abstract

There are currently several reported techniques of sonographic subcutaneous adipose tissue (SAT) measurement described in the literature. This systematic review aims to report techniques of SAT measurement using ultrasonography. A systematic literature search was performed and identified 39 relevant articles using ultrasonography to quantify abdominal SAT. The following parameters were collected: type of measurement, ultrasound machine make/model, transducer frequency, external/internal landmarks, pressure applied on probe, special techniques and inter-/intraobserver reliability. Literature findings related to the above parameters were summarized. A summary of the most common techniques and parameters is provided, serving as a reference for a necessary standardized approach.

Ultrasound measures of abdominal fat layers correlate with metabolic syndrome features in patients with obesity

“…21 (Figure 3), were sequentially measured. 5,6,22 All these measures were made where the abdominal aorta ultrasound imaging bifurcates into the iliac arteries, position corresponding to the fourth lumbar vertebra level (L4), using the usual reference point when measuring visceral fat with CT and MRI. 5,22 Good correlation between CT assessed intraabdominal fat F I G U R E 1 Echographic superficial, profound subcutaneous fat and preperitoneal fat subcutaneous fat is divided by the fascia superficialis (strong white line) and preperitoneal fat (between the linea alba and the peritoneum).…”

“…High adiponectin secretion in the subcutaneous abdominal layer is protective in terms of cardiovascular risk reduction, 4 whereas visceral fat 5 is known to secrete many insulin-resistance deleterious cytokines such as TNF, IL6, leptin, resistin or visfatin. 4 Structured ultrasound imaging of abdominal adipose tissue is a cheap, nonradiation, easy-to-learn methodology, able not only to differentiate between superficial and profound subcutaneous fat layers 6,7 but also to look easily into deeper layers (preperitoneal) fat, 8 omental (intraperitoneal) fat 9 and perirenal (retroperitoneal) fat, 10 all of them included under the concept of 'visceral adiposity' measured using classic body composition techniques.…”

“…Structured ultrasound imaging of abdominal adipose tissue is a cheap, nonradiation, easy‐to‐learn methodology, able not only to differentiate between superficial and profound subcutaneous fat layers 6,7 but also to look easily into deeper layers ( preperitoneal ) fat, 8 omental (intraperitoneal) fat 9 and perirenal (retroperitoneal) fat, 10 all of them included under the concept of ‘visceral adiposity’ measured using classic body composition techniques.…”

Matrix Gla protein regulates adipogenesis and is serum marker of visceral adiposity

“…The characteristic that high expression and activity of β3-adrenoreceptors and fewer insulin receptor makes visceral adipose more capable of metabolizing lipids than other fat types [7]. Subcutaneous adipose provides insulation, cushioning, and serves as a long-term energy storage depot [8]. Usually, subcutaneous fat is not harmful for health, while excess visceral fat is linked to obesity-related diseases, such as type 2 diabetes, insulin resistance, and inflammatory diseases [9,10].…”

Greater Reduction in Abdominal Than in Upper Arms Subcutaneous Fat in 10- to 12-Year-Old Tennis Players: A Volumetric MRI Study

“…DXA may also differentiate visceral from subcutaneous fat in the abdominal region, although with lower precision than MRI and CT (23). Ultrasonography allows measuring the thickness of the SAT but is less reliable and precise than MRI and CT (24, 25). Other techniques such as bioelectrical impedance analysis, anthropometric measurements (body mass index, waist-to-hip-ratio, waist circumference, or skinfold thickness) provide indirect estimations of regional fat distribution (24).…”