Emphysema quantification using hybrid versus model-based generations of iterative reconstruction: SAFIRE versus ADMIRE.

To compare 2 incompatible generations of iterative reconstructions from the same raw dataset based on automatic emphysema quantification and noise reduction: a hybrid algorithm called sinogram affirmed iterative reconstruction (SAFIRE) versus a model-based algorithm called advanced modeled iterative reconstruction (ADMIRE). Raw datasets of 40 non-contrast thoracic computed tomography scanners obtained from a single acquisition on a SOMATOM Definition Flash unit (Siemens Healthcare, Forchheim) were reconstructed with 3 levels of SAFIRE and ADMIRE algorithms resulting in a total of 240 datasets. Emphysema index (EI) and image noise were compared using repeated analysis of variance (ANOVA) analysis with a P value <.05 considered statistically significant. EI and image noise were stable between both generations of IR when reconstructed with the same level (P >= 0.31 and P >= 0.06, respectively). SAFIRE and ADMIRE perform equally in terms of emphysema quantification and noise reduction.