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Updated: Jul 10, 2026

X-ray Dose Reduction through Adaptive Exposure in Fluoroscopic Imaging
Published on: September 11, 2011
Relationship between Water-equivalent Diameter, Computed Tomography Dose Indices, and Image Noise in Pediatric Head
Evi Setiawati1, Choirul Anam1, Bella Diani Safitri1
1Department of Physics, Faculty of Sciences and Mathematics, Diponegoro University, Semarang, Indonesia.
Purpose:
This study investigated the relationships among water-equivalent diameter (Dw), volume computed tomography dose index (CTDIvol), size-specific dose estimate (SSDE), and image noise in pediatric head computed tomography (CT) under active and inactive tube current modulation (TCM).
Subjects And Methods:
Fifty pediatric patients (0-14 years) undergoing noncontrast head CT were retrospectively analyzed. Scans were performed on a 128-slice CT scanner at 120 kVp. Twenty-five patients were examined using active TCM, and 25 with fixed tube current. CTDIvol and SSDE were calculated using IndoseCT software following American Association of Physicists in Medicine TG-293 recommendations. Image noise was quantified using the global noise index. Relationships among Dw, CTDIvol, SSDE, and noise were evaluated using linear regression.
Results:
Active TCM reduced CTDIvol from 38.5 ± 7.1 mGy to 32.8 ± 6.4 mGy (15.4%, P = 0.021) and SSDE from 39.2 ± 6.1 mGy to 29.6 ± 5.3 mGy (24.5%, P < 0.001). Image noise decreased from 10.2 ± 2.3 HU to 8.6 ± 1.9 HU (P = 0.037).
Conclusion:
Active TCM improves dose-noise efficiency in pediatric head CT by reducing radiation dose while maintaining stable image quality. Integration of Dw-based SSDE with automated noise analysis provides a quantitative framework for pediatric CT dose auditing and may support the development of size-specific diagnostic reference levels.
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