Feasibility Study on Bone Mineral Density Measurement Based on Dual-Layer Flat Panel Detector

Bone mineral density (BMD) measurement plays a crucial role in the diagnosis and management of osteoporosis and other bone-related diseases. The most widely used clinical methods include dual-energy x-ray absorptiometry. Recently, BMD measurement techniques utilizing flat-panel detectors (FPDs) have been actively researched. In this paper, we study the feasibility of using the dual-layer flat-panel detector (DFD) to estimate BMD with a single exposure instead of the conventional method of estimating BMD through dual exposure with x-rays of different energies and switching filters. DFD enables single-exposure spectral imaging based on energy-selective imaging from beam hardening and can be applied to the material decomposition. We first review existing BMD measurement techniques and mathematical models based on dual-energy FPD within small variations of BMD. We then extend the method to the DFD case, where upper and lower images are acquired with different energy spectra. Through extensive experiments, we compare BMD measurement accuracy of the single-exposure DFD method with the conventional dual-exposure method for different x-ray tube voltages. Through observations in this paper, we showed the possibility of measuring BMD using single-exposure-based DFD.