Intraindividual variation of dose parameters in oncologic CT imaging

Area of Science:

• Radiology
• Medical Imaging
• Radiation Oncology

Background:

• Computed tomography (CT) involves radiation exposure, necessitating dose optimization.
• Understanding factors influencing radiation dose is crucial for patient safety and effective tumor staging/follow-up.

Purpose of the Study:

• To identify key factors affecting radiation dose in chest, abdomen, and pelvis CT scans.
• To analyze the intraindividual impact of imaging parameters and patient factors on CT dose estimates.

Main Methods:

• Retrospective analysis of patients with at least two consecutive CT examinations.
• Correlation of CT dose estimates (CTDIvol, DLP, SSDE) with patient BMI, scan length, and technical parameters (tube current, kVp, pitch, noise, iterative reconstruction).
• Application of univariate and multivariate linear mixed-effects models with repeated-measures analysis and Bonferroni adjustments.

Main Results:

• Tube current substantially affected all dose estimates across all imaging regions.
• Iterative reconstruction significantly influenced dose estimates in thoracoabdominopelvic scans and DLP/SSDE in chest CT.
• Pitch factor impacted all dose parameters in thoracoabdominopelvic CT scans.

Conclusions:

• Tube current is a pivotal factor in radiation dose management for CT.
• Iterative reconstruction algorithms can significantly reduce radiation dose, particularly in thoracoabdominopelvic and chest CT.
• Maintaining a pitch factor of ≥1.0 is recommended for radiation dose reduction.