Kevin Lian MD, Presenter: Nothing to Disclose

Brian Black BSc, Abstract Co-Author: Nothing to Disclose

Stephen Choy MD, Abstract Co-Author: Nothing to Disclose

Ana-Maria Bilawich MD, Abstract Co-Author: Nothing to Disclose

Jason Ronald Shewchuk MD, Abstract Co-Author: Nothing to Disclose

Katharine Grant PhD, Abstract Co-Author: Employee, Siemens AG

Patrick McLaughlin FFR(RCSI), Abstract Co-Author: Nothing to Disclose

Savvas Nicolaou MD, Abstract Co-Author: Nothing to Disclose

Accurate interpretation of Head CT demands high image contrast and spatial resolution from a CT system. This study aims to assess the image quality effects of a novel third generation modelled iterative reconstruction algorithm (SAFIRE+, Siemens Healthcare, Forcheim, Germany) compared to the prior generation of SAFIRE in helical non contrast CT of the head.

50 consecutive patients underwent helical unenhanced head CT over a 5 day period using a dual source 128-slice CT system. Images were reconstructed with standard FBP, SAFIRE (strength 1, 3, 5) and SAFIRE+ (strength 1, 3, 5). Objective and subjective image quality were compared between images reconstructed with SAFIRE and SAFIRE+ at corresponding strength levels. Objective measures of image quality include image noise, signal-to-noise ratio, and contrast-to-noise ratio. Subjective rating of grey-white differentiation, coarse noise, posterior fossa streak artifact, and overall diagnostic acceptability were scored out of 10 by two reviewers in consensus. Statistical analysis was performed with paired student’s t-test and Wilcoxon signed rank test.

SAFIRE+ demonstrated statistically significant reduction in objective noise and improvement in signal-to-noise ratio at all reconstruction strengths (p<0.01 for all comparisons). SAFIRE+5 showed significant improvement in contrast-to-noise ratio as compared with SAFIRE5 (2.0±0.6 vs 1.8±0.5, p<0.01). There was a statistically significant improvement in grey-white differentiation, diagnostic acceptability, streak artifact, and subjective noise when SAFIRE+5 images were subjectively compared with SAFIRE5.

Third generation modelled iterative reconstruction offers improvement in both objective and subjective image quality of head CT. Subjective and objective benefits over SAFIRE were better appreciated at higher reconstruction strengths.

SAFIRE+ is an easy software upgrade that offers evolutionary improvements in image quality which may enhance diagnostic accuracy and better guide clinical decisions.

Lian, K, Black, B, Choy, S, Bilawich, A, Shewchuk, J, Grant, K, McLaughlin, P, Nicolaou, S, Improvements in Subjective and Objective Image Quality in Emergency Non-contrast CT of the Head, Reconstructed with a Novel Third-generation Modelled Iterative Reconstruction Algorithm.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14009025.html