# Low-Cost, Low-Dose Flat Panel X-ray Detectors with a Novel Semiconductor

> **NIH NIH R44** · CAPESYM, INC. · 2020 · $834,153

## Abstract

Project Summary/Abstract
After decades of advances in medical imaging, X-ray based imaging modalities are still the backbone of modern
general and targeted diagnostic and therapeutic imaging. With the advent of flat panel detector technology, flat
panel X-ray imagers (FPXIs) are now widely used in digital radiography, fluoroscopy, digital tomosynthesis,
image-guided radiation therapy, and cone beam computed tomography. The majority of commercial FPXIs are
based on scintillators and rely on indirect conversion of X-rays to photons and then to electronic signals, and a
smaller portion is based on amorphous selenium (a-Se) semiconductor films that directly convert absorbed X-
rays to an electronic signal. The indirect FPXIs have high detective quantum efficiency (DQE) over the energy
range of interest (up to 140kVp) and are used in most of the flat panel imaging applications. However, the
isotropic propagation of light in the scintillators adversely affects the quality of obtained images, and high
radiation doses are needed to obtain images with acceptable brightness and contrast. On the other hand, a-Se
based direct-conversion panels have excellent spatial resolution and DQE, but only up to 40kVp, due to low
absorptivity of a-Se at higher energies. Thus, the use of direct-conversion FPXIs is currently limited only to soft-
tissue applications, primarily mammography. In this program, we will develop direct-conversion FPXIs with a
novel semiconductor sensor with high sensitivity at X-ray energies up to 140kVp. In Phase I, the feasibility of
this semiconductor X-ray sensor was evaluated and excellent results in terms of sensitivity, response linearity,
charge transport properties, and stability were obtained. The Phase II program is focused on demonstration of
X-ray imagers based on the novel sensor, including large area FPXIs suitable for transitioning to clinical testing,
and scalable X-ray scanner modules suitable for medical, scientific research, and industrial imaging applications.

## Key facts

- **NIH application ID:** 10080930
- **Project number:** 2R44EB028208-02
- **Recipient organization:** CAPESYM, INC.
- **Principal Investigator:** Amlan Datta
- **Activity code:** R44 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $834,153
- **Award type:** 2
- **Project period:** 2019-04-15 → 2022-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10080930

## Citation

> US National Institutes of Health, RePORTER application 10080930, Low-Cost, Low-Dose Flat Panel X-ray Detectors with a Novel Semiconductor (2R44EB028208-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10080930. Licensed CC0.

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