Abdominal obesity, or fat that accumulates around one's stomach and abdomen, has long been considered to pose a high health risk in individuals. Hence, measurement of "central obesity"--as it's often called--helps predict propensity to disorders caused by excess weight in the abdominal area.
"Recent studies have shown that abdominal obesity is linked with diseases such as congestive heart failure and metabolic syndrome," said author Jin Keun Seo. "Static electrical impedance tomography, or EIT, could be employed as a non-invasive surrogate of disease progression in these conditions."
"Compared to CT, EIT is more advantageous since it is non-ionizing and can hence be used for continuous patient self-monitoring to track body fat status in daily routines," Seo explained. "Unlike CT and MRI, EIT is a low cost, portable, and easy-to-use bedside technique to image electrical conductivity distribution."
Multi-frequency EIT (MFEIT) reconstructs the image of conductivity inside the human body based on this dependence of tissue conductivity on frequency. And since bone, muscle, and fat conduct electricity differently over various frequencies, MFEIT can use data of the boundary current-voltage relationship at diverse frequencies to estimate the amount of fat. Again, since body fat is less conductive than water and tissues such as muscle, this difference can be used to estimate the thickness of visceral and subcutaneous adipose tissue.
One issue with EIT is that the technique is prone to forward-modeling errors; these errors often include boundary geometry and electrode position uncertainties. In this paper, authors propose a new reconstruction method that compensates for this pitfall of EIT, using prior anatomical information at the expense of spatial resolution, and improving reproducibility. Numerical simulations demonstrate that the result of reconstruction is satisfactory in identifying subcutaneous fat.
Further research is needed to take advantage of the frequency dependent behavior of human tissue to estimate the distribution of visceral fat. "Current experimental work has shown promising results in detecting subcutaneous fat thickness as confirmed with ultrasound imaging," said Hyeuknam. "Future work is needed to determine the volume of visceral fat in patients with metabolic and cardiovascular disorders."
###
Source article: Mathematical Framework for Abdominal Electrical Impedance Tomography to Assess Fatness. SIAM Journal on Imaging Sciences
The Society for Industrial and Applied Mathematics (SIAM), headquartered in Philadelphia, Pennsylvania, is an international society of more than 14,000 individual, academic and corporate members from 85 countries. SIAM helps build cooperation between mathematics and the worlds of science and technology to solve real-world problems through publications, conferences, and communities like chapters, sections and activity groups.
SIAM Journal on Imaging Sciences