Utilisation of Objective and Subjective Image Quality Metrics to Guide Optimal Contrast Volumes for Abdominal CT

Area of Science:

• Radiology
• Medical Imaging
• Computed Tomography

Background:

• Determining optimal iodinated contrast media (ICM) volume for abdominal CT is challenging.
• Limited evidence exists on ICM volume for consistent enhancement and subjective image quality.
• Current fixed-volume dosing may not be ideal for all patients.

Purpose of the Study:

• Compare fixed-volume versus weight-based ICM dosing strategies.
• Evaluate objective enhancement and subjective image quality.
• Identify optimal ICM dosing for diagnostic performance in abdominal CT.

Main Methods:

• Revised abdominal CT protocol from fixed (100 mL) to weight-based (1 mL/kg) ICM dosing.
• Matched 90 procedures per group by age, gender, weight, and kVp.
• Assessed objective enhancement (Hounsfield units) and subjective image quality (VGC analysis).

Main Results:

• Weight-based dosing reduced the dependence of enhancement on patient size.
• Lighter patients (<90 kg) required greater Hounsfield unit enhancement for equal subjective image quality compared to heavier patients.
• Visual grading characteristic analysis revealed differences in subjective image quality perception.

Conclusions:

• Weight-based ICM dosing achieves consistent objective enhancement across patient sizes in abdominal CT.
• Consistent objective enhancement does not guarantee consistent subjective image quality.
• Further optimization of ICM dose strategies is needed, potentially tailoring doses for lighter patients to enhance subjective image quality.