  Dual-energy X-ray absorptiometry (DEXA) has been widely applied to measure
bone mineral density (BMD) and soft-tissue composition of human body. However,
the use of DEXA is greatly limited for low-Z materials such as soft tissues due
to their weak absorption. While X-ray phase-contrast imaging (XPCI) shows
significantly improved contrast in comparison with the conventional standard
absorption-based X-ray imaging for soft tissues. In this paper, we propose a
novel X-ray phase-contrast method to measure the area density of low-Z
materials, including a single-energy method and a dual-energy method. The
single-energy method is for the area density calculation of one low-Z material,
while the dual-energy method is aiming to calculate the area densities of two
low-Z materials simultaneously. Comparing the experimental and simulation
results with the theoretic ones, the new method proves to have the potential to
replace DEXA in area density measurement. The new method sets the prerequisites
for future precise and low-dose area density calculation method of low-Z
materials.
