클립 확인 목적 유방 X선촬영에서 그리드 사용 여부에 따른 방사선 선량 및 영상 화질 변화: 팬텀 연구

Abstract

This study quantitatively evaluated the impact of anti-scatter grid use on radiation dose and image quality in digital mammography for clip verification. An acrylic breast phantom embedded with a titanium clip was imaged under automatic exposure control (AEC) with simulated breast thicknesses ranging from 1 to 6 cm. The use of an anti-scatter grid increased the tube current–time product (mAs) and average glandular dose (AGD) by approximately 1.9 times compared with gridless conditions. While the grid improved lesion-related image quality parameters, including contrast-to-noise ratio (CNR1) and signal-to-noise ratio (SNR1), the visibility index for the metallic clip (CNR2) was higher without a grid, whereas SNR2 was higher with a grid. Correlation and regression analyses demonstrated a strong positive relationship between breast thickness and dose indices, with a significant thickness×grid interaction indicating a supra-linear dose increase in thicker breasts. All image quality metrics exceeded diagnostic thresholds (CNR  4.0, SNR  10.0). For thinner breasts (1–4.5 cm), grid removal effectively reduced unnecessary radiation exposure while maintaining clinically acceptable image quality. These findings suggest that selective grid use tailored to imaging purpose and breast thickness can optimize radiation dose while preserving diagnostic confidence, aligning with the ALARA (as low as reasonably achievable) principle