THE SIZE-SPECIFIC DOSE ESTIMATE (SSDE) FOR TRUNCATED COMPUTED TOMOGRAPHY IMAGES

Area of Science:

• Medical Physics
• Radiological Imaging
• Radiation Dosimetry

Background:

• Truncated axial images in computed tomography (CT) can affect dose calculations.
• Accurate patient dosimetry is crucial for radiation safety in CT examinations.

Purpose of the Study:

• To investigate truncated axial CT images in a clinical setting.
• To develop correction factors for abdomen, thoracic, and head regions to accurately predict water-equivalent diameter (DW) and size-specific dose estimate (SSDE).

Main Methods:

• Analysis of axial CT images from 75 patients.
• Characterization of truncated images by truncation percentage (TP).
• Calculation of correction factors based on DW values from truncated versus non-truncated images.

Main Results:

• Thoracic images were most frequently truncated (86.2%), followed by abdominal (48.1%) and head (9.1%).
• Correction factors increase exponentially with increasing TP.
• Corrected DW and SSDE were significant for truncated thoracic images, but not for abdominal or head regions.

Conclusions:

• Correction factors can accurately estimate DW and SSDE from truncated CT images.
• The developed correction factors are particularly relevant for thoracic CT imaging where truncation is common.