Extent of tube-current reduction using sinogram affirmed iterative reconstruction in pediatric computed tomography:...

Area of Science:

• Medical Imaging
• Radiology
• Image Processing

Background:

• Iterative image reconstruction (IIR) techniques enhance computed tomography (CT) image quality at reduced radiation doses.
• Optimizing IIR parameters is crucial for pediatric CT protocols.

Purpose of the Study:

• To quantify radiation dose reduction in pediatric CT scans.
• To determine optimal iterative reconstruction strengths for diagnostic image quality.

Main Methods:

• An anthropomorphic phantom simulating a 5-year-old patient was scanned using standard CT protocols.
• Images were reconstructed using filtered back projection (FBP) and varying strengths of sinogram affirmed iterative reconstruction (SAFIRE).
• Contrast-to-noise ratios (CNR) were measured in various anatomical regions.

Main Results:

• Optimal SAFIRE strengths were identified as 3 for head/chest and 4 for abdomen, yielding approximately 50% CNR increase.
• A tube-current reduction factor of 1.2 was calculated for head scans.
• Reduced tube current head scans matched FBP CNR with full tube current.

Conclusions:

• Optimal iterative reconstruction strengths were established for pediatric head, chest, and abdomen CT.
• A 20% reduction in tube current is achievable without compromising diagnostic image quality, leading to significant radiation dose reduction.