Radiation dose reduction with Sinogram Affirmed Iterative Reconstruction technique for abdominal computed tomography.

Area of Science:

• Medical Imaging
• Radiology
• Image Reconstruction

Background:

• Filtered back-projection (FBP) is a standard reconstruction technique for computed tomography (CT).
• Iterative reconstruction techniques aim to improve image quality and reduce radiation dose.
• Sinogram Affirmed Iterative Reconstruction (SAFIRE) is an advanced iterative reconstruction algorithm.

Purpose of the Study:

• To evaluate the impact of SAFIRE and FBP on abdominal CT image quality at 50% and 75% radiation dose reductions.
• To compare lesion detection, image noise, and diagnostic confidence between SAFIRE and FBP at reduced doses.

Main Methods:

• Prospective study of 24 patients undergoing abdominal CT with a 128-slice scanner.
• Acquisition of images at standard dose (200 mAs), 50% reduced dose (100 mAs), and 75% reduced dose (50 mAs).
• Reconstruction using FBP and four levels of SAFIRE (S1-S4); image analysis by two abdominal radiologists.

Main Results:

• All lesions were detected with both FBP and SAFIRE.
• SAFIRE images showed acceptable subjective noise at all reduced doses, unlike FBP.
• Objective noise was significantly reduced with SAFIRE compared to FBP at 75% reduced dose (P < 0.001).
• SAFIRE images were diagnostically acceptable in all patients at 50% reduced dose and 22/24 patients at 75% reduced dose.

Conclusions:

• SAFIRE enables abdominal CT imaging with preserved diagnostic value at 50% radiation dose reduction.
• SAFIRE also provides acceptable diagnostic quality in some patients even with a 75% radiation dose reduction.
• SAFIRE represents a promising technique for dose reduction in abdominal CT.