Room: AAPM ePoster Library
Purpose: To investigate the feasibility of novel indirect flat panel detector (FPD) system to remove scattered radiation for mammography.
Methods: We have been proposed the novel indirect FPD system for general radiographic examination. Proposed FPD has a net-like Pb in the substrate layer matching the ineffective area on the thin film transistor (TFT) layer, thus Pb does not block the effective area where detect the signal from the scintillation layer. According to previous study, the novel FPD system indicated better performance for low range of incident X-ray (~40kV), therefore we have introduced this novel concept into the FPD for mammography.
To evaluate the performance of proposed system for mammography, we conducted a Monte Carlo simulation using MCNPX 2.7.0 software. RQA-M2 (28kVp, Mo/Mo, 2 mm Al-filtration) of continuous spectrum was exposed to 2, 4, and 6 cm-thickness Polymethyl methacrylate (PMMA) phantom to compute scatter fractions (SFs) with 3 different systems such as no-grid, linear grid (5:1 grid ratio), and the novel system. Simulated indirect FPD system has 81.5 µm² of pixel size with 10 µm-ineffective area in the border of pixels, thus the effective area of pixels is 71.5 µm². 10 µm-thickness of Pb was embedded in substrate layer matching the ineffective area on TFT layer for the novel system only.
Results: SFs of novel system were lower than those of the other system at all thickness of PMMA phantom (2, 4, and 6 cm). Images of 3 different systems were acquired by simulation and the artifacts like a grid-pattern were shown in the image with linear grid system only.
Conclusion: The novel indirect FPD system to remove scattered radiation for mammography has the potential for improving the image quality of mammography as reducing the scattered radiation comparing with the conventional linear grid system.
Funding Support, Disclosures, and Conflict of Interest: This work was supported by a Grant-in-aid for Scientific Research for Young Scientists (JSPS KAKENHI Grant Number 19K17238)