Iterative Reconstruction Technique Reduces CT Dose

A newly adapted low-dose technique called adaptive statistical iterative reconstruction (ASIR) may enable radiologists to reduce patient radiation exposure from CT up to 65%, according to a study published in the September issue of the American Journal of Roentgenology. Currently, CT scans are responsible for more than two thirds of the total radiation dose associated with medical imaging exams.
 
“We found nearly identical image quality using the reduced dose CT method with ASIR compared with the standard dose CT method without ASIR,” says Amy Hara, MD, lead author of the study, which was performed at the Mayo Clinic Arizona in Scottsdale.
 
Iterative reconstruction is a technique that allows radiologists to reduce the noise in an image and improve image quality (like adjusting a TV antenna to make a “fuzzy” image sharper), while significantly reducing the radiation dose. CT scans using the newly adapted low-dose ASIR method and the standard-dose method without ASIR were performed both on a phantom and 12 patients.
 
“In our study, patient radiation doses were reduced up to 65% using the low-dose IR method,” says Hara. “The average radiation dose delivered during the low-dose CT with IR was 470 mGy; the average dose delivered using the standard-dose CT without IR was 894 mGy.”
 
“In future studies, it will be important to not only evaluate image quality but to assess diagnostic accuracy,” Hara says. “ASIR is new to CT but in our practice it has been very successful.”

— Source: American Roentgen Ray Society