A CMOS active pixel sensor system for laboratory- based x-ray diffraction studies of biological tissue

Area of Science:

• Medical Imaging
• Materials Science
• Biophysics

Background:

• X-ray diffraction (XRD) provides crucial material-specific data for biological tissues.
• Current digital X-ray detectors often lack the required large area, low noise, and wide dynamic range for laboratory XRD.
• Advancements in detector technology are needed for enhanced laboratory-based XRD applications.

Purpose of the Study:

• To introduce and demonstrate the feasibility of CMOS active pixel sensor (APS) technology for coherent scatter imaging.
• To evaluate the potential of APS as a digital X-ray detector for material-specific biological tissue analysis.
• To assess APS performance in angle dispersive X-ray diffraction (ADXRD) for medical applications.

Main Methods:

• A prototype CMOS APS was integrated into an X-ray diffraction system utilizing an industrial X-ray source and beam filtration.
• Experimental setup, including collimator options and detector parameters, was optimized for ADXRD.
• Scatter signatures were measured for 11 materials relevant to breast cancer diagnosis, kidney stone identification, and bone mineral density.

Main Results:

• The APS successfully recorded biologically relevant coherent scatter signatures for various materials and mixed samples.
• Experimental results were validated against two independent predictive models (linear systems model and linear superposition integral).
• Coherent scatter signatures demonstrated sensitivity to sample composition, enabling quantification.

Conclusions:

• CMOS APS technology shows significant potential for fulfilling the requirements of laboratory-based X-ray diffraction studies.
• The ability to quantify sample composition using coherent scatter signatures opens new diagnostic avenues.
• Future development of bespoke APS imagers could facilitate clinical translation of coherent scatter X-ray diffraction.