MBIR pushes CT liver radiation dose lower than ASIR

Model-based iterative reconstruction (MBIR) reduced radiation and noise levels in CT liver scans without diminishing image quality, according to a study published in the September issue of Radiology.

MBIR (GE Healthcare) delivered a mean radiation dose 59 percent lower than the radiation dose of images reconstructed with adaptive statistical iterative reconstruction ASIR (6.7 mGy vs16.4 mGy), according to William P. Shuman, MD, of the University of Washington School of Medicine, in Seattle, and colleagues.

The authors designed the prospective, single-institution study to compare the quality of images reconstructed with MBIR and ASIR and their “depiction of clinically relevant findings.”

ASIR is a partially iterative technique that lowers image noise and radiation dose below the rate of traditional filtered back projection, according to the authors. MBIR reduces image noise and radiation even further, they added.

The study enrolled 50 patients with a mean age of 57 between April and August of 2012. The patients had undergone prior CT that showed advanced cirrhosis and were scheduled for follow-up multiphase liver CT.

The study’s four readers found that MBIR delivered similar or better quality images than ASIR, according to Shuman and colleagues. “MBIR may allow substantial radiation dose reduction in liver CT without compromising depiction of clinically relevant findings and with acceptable or improved image quality.”