Automatic spectral imaging protocol selection and iterative reconstruction in abdominal CT with reduced contrast...

Area of Science:

• Radiology
• Medical Imaging
• Computed Tomography

Background:

• Multiphase abdominal CT often requires high contrast agent doses.
• Optimizing contrast and radiation dose in CT is crucial for patient safety and diagnostic accuracy.

Purpose of the Study:

• To assess the feasibility, image quality, and radiation dose of spectral CT imaging with automatic protocol selection (ASIS) and adaptive statistical iterative reconstruction (ASIR).
• To evaluate the effectiveness of reduced contrast agent dose in abdominal multiphase CT.

Main Methods:

• 160 patients were randomized into two groups: Protocol A (120 kVp, 450 mgI/kg, filtered back projection) and Protocol B (spectral CT, ASIS, 40-70 keV monochromatic images, 300 mgI/kg, ASIR).
• Quantitative (noise, CNR) and qualitative (image quality, enhancement) parameters were compared between protocols.

Main Results:

• Spectral CT at 50-60 keV with ASIR yielded comparable or lower noise and higher contrast/image quality than 120 kVp with FBP.
• A 33% reduction in contrast agent dose was achieved with Protocol B.
• Radiation dose was similar between both protocols.

Conclusions:

• ASIR and ASIS enable contrast agent dose reduction in spectral abdominal CT while maintaining diagnostic image quality.
• Spectral CT with reduced contrast (300 mgI/kg) and ASIR is feasible for abdominal imaging.
• 50-keV monochromatic images with 50% ASIR offer optimal image quality.