3-D dose reduction technique improves image quality of low-dose CT scans

Japanese researchers have found that using the adaptive iterative dose reduction (AIDR) 3-D technique can improve image quality in reduced- or low-dose CT scans on patients with pulmonary diseases.

In an article published in the October issue American Journal of Roentgenology, the research team led by Yoshiharu Ohno of Kobe University Graduate School of Medicine also reported that using this reconstruction technique with reduced- or low-dose CT scans resulted in almost "perfect" inter-reader agreement.

In the study, chest CT scans at three different tube current settings using 16- and 64-MDCT scanners were performed on 37 patients with pathologically diagnosed lung cancer and other pulmonary diseases.

In order to compare image quality, readers quantified image noise by region of interest measurements. They also were asked to evaluate the likelihood of the occurrence of emphysema, ground-glass opacity, reticular opacity, bronchiectasis, honeycomb pattern and nodules.

The authors found that the image quality scores of reduced- and low-dose CT without AIDR 3-D were "significantly lower" than those of both protocols with AIDR and standard-dose CT.

In addition, inter-reader agreement in scans processed using AIDR 3-D for emphysema, ground-glass opacity, bronchiectasis, honeycomb pattern, and nodules was nearly "perfect," the authors wrote.

"Our results suggest that AIDR 3-D is useful for reduced- and low-dose chest CT examinations at 50 and 25 mAs without significant degradation of image quality and radiologic findings assessment compared with those obtained with standard-dose CT protocols," the authors wrote.

Additionally, according to the authors, because there is no reconstruction time penalty associated with AIDR 3-D compared to protocols using the standard field back projection algorithm, "the use of AIDR 3-D can be considered acceptable for routine clinical use."

The AIDR 3-D technology used by researchers was developed by Toshiba, and in April was cleared by the Food and Drug Administration.

For more:
- read the study
- check out the Toshiba announcement