RSNA: Iterative reconstruction speeds CCTA analysis
CHICAGO—Iterative reconstruction can significantly decrease the time and number of manual adjustments needed for post-processing of coronary CT angiography (CCTA) compared with traditional filtered back projection (FBP), according to research presented Nov. 28 at the 97th Scientific Assembly and Annual Meeting of the Radiological Society of North America (RSNA).

J. Reid Spears, clinical research coordinator at Medical University of South Carolina in Charleston, and colleagues wanted to investigate the effect that iterative reconstruction had on image noise, image quality and workflow.

The researchers took CCTA data from 50 patients who had been investigated using a second-generation, dual-source CT system using either retrospective ECG gating or prospective ECG triggering. Data were reconstructed with iterative reconstruction using an algorithm called IRIS (iterative reconstruction in image space). Data were also reconstructed using traditional FBP algorithms and two radiologists independently evaluated the reconstructions.

IRIS reduced images noise compared to FBP (23.3 Hounsfield Units for IRIS versus 33.5 for FBP) without a significant difference in attenuation. Subjective image quality with IRIS was 3.2 (on a five point scale) compared with 3.0 for FBP. IRIS decreased the time needed for coronary segmentation by an average of 16.7 seconds compared with FBP and the required number of manual adjustments needed for IRIS (5.7) was also lower than for FBP (6.8).

In light of the results, the researchers concluded that iterative reconstruction algorithms can positively impact workflow for post-processing of CCTA, owing the effect to the suppression of image noise and improving automated vessel segmentation.