Noise reduction algorithm enhanced image quality in pediatric patients

Issue: August 2011

SCCT 6th Annual Meeting

DENVER — With the use of a novel 3-D edge-sensitive noise reduction image space algorithm, researchers were able to improve image quality of low radiation-dose electrocardiogram-gated cardiac CT angiograms in pediatric patients.

The algorithm is the end result of a 2-year collaboration between trial investigator Jeffrey C. Hellinger, MD,and engineers from Vital Images.

“This algorithm is applies on a 3-D, it preserves the edge of a structure and minimizes such that there is visual improvement in the structure of interest — in this case, the CV system,” Hellinger, an associate professor of radiology and pediatrics at Stony Brook University Medical Center, told Cardiology Today. “In comparison to the latest use of iterative reconstruction for low-dose CT angiography, this algorithm is very unique in that it is a multimodality, multivendor, user-interactive application that is performed on a workstation.”

In all, the study included 25 retrospective ECG-gated pediatric cardiac CTAs that were performed for the analysis of congenital heart disease. Researchers recorded density and noise measurements during systole and diastole on an independent work station for the calculation of the signal-to-noise ratio (SNR) and the carrier-to-noise ratio (CNR).

In the original images, they reported that noise for all levels was 70.3, the SNR was 11.7 and the CNR was 8.74. The noise decreased to 41.2 with medium filters, whereas with smooth filters, it decreased to 32.8.

Furthermore, they found that the degree of enhancement stayed similar with a statistically significant increase in the ratios for both the medium filter (SNR, 19.6; CNR, 14.5) and the smooth filter (SNR, 26.3; CNR, 18.76; P<.001).

“The goal for every CT Angiogram, in particular for pediatric patients, is to of use the lowest dose possible while maintaining diagnostic quality. Traditionally this concept has been applied only to the CT scanner itself by using lower radiation parameters and applying reconstruction algorithms.

“With this new algorithm, instead of just thinking of a workstation as a visualization tool, you can now think of the workstation as a method for radiation reduction and patient safety. If you have this algorithm at your disposal when you acquire a study, the dose can be dialed down, anticipating recovering the image quality during image review and interpretation on the workstation.”– by Brian Ellis

Disclosures: Dr. Hellinger reports no relevant financial disclosures.

For more information:

Hellinger J. Abstract #19. Presented at: The 6th Annual Scientific Meeting of the Society of Cardiovascular Computed Tomography; July 14-17, 2011; Denver.

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