Relationship between Water-equivalent Diameter, Computed Tomography Dose Indices, and Image Noise in Pediatric Head...

Area of Science:

• Radiological Physics
• Medical Imaging Technology
• Pediatric Radiology

Background:

• Optimizing radiation dose in pediatric computed tomography (CT) is crucial for minimizing long-term risks.
• Tube Current Modulation (TCM) is a technique used to adjust radiation output based on patient anatomy.
• Evaluating dose and image quality metrics like CTDIvol, SSDE, and noise is essential for effective dose management.

Purpose of the Study:

• To investigate the impact of active versus inactive tube current modulation (TCM) on dose and image noise in pediatric head CT.
• To analyze the relationships between water-equivalent diameter (Dw), CTDIvol, SSDE, and image noise under different TCM settings.
• To assess the dose-noise efficiency of active TCM in pediatric head CT examinations.

Main Methods:

• Retrospective analysis of noncontrast head CT scans from 50 pediatric patients (0-14 years).
• Scans were performed using a 128-slice CT scanner with either active TCM or fixed tube current.
• CTDIvol and SSDE were calculated using IndoseCT software; image noise was quantified using the global noise index.

Main Results:

• Active TCM significantly reduced CTDIvol by 15.4% and SSDE by 24.5% compared to fixed tube current.
• Image noise was also reduced with active TCM, decreasing by an average of 15.7%.
• Statistical analysis confirmed significant reductions in both dose metrics and noise with active TCM (P < 0.05).

Conclusions:

• Active TCM effectively improves dose-noise efficiency in pediatric head CT, lowering radiation dose while maintaining image quality.
• The integration of Dw-based SSDE and automated noise analysis offers a robust framework for pediatric CT dose auditing.
• This approach may facilitate the establishment of size-specific diagnostic reference levels for pediatric CT protocols.