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Value of a noise-optimized virtual monoenergetic reconstruction technique in dual-energy CT for planning of transcatheter aortic valve replacement

Simon S Martin, Moritz H Albrecht, Julian L Wichmann, Kristina Hüsers, Jan-Erik Scholtz, Christian Booz, Boris Bodelle, Ralf Bauer, Sarah C Metzger, Thomas J Vogl & Thomas Lehnert

abstract

OBJECTIVES
To evaluate objective and subjective image quality of a noise-optimized virtual monoenergetic imaging (VMI+) reconstruction technique in dual-energy computed tomography (DECT) angiography prior to transcatheter aortic valve replacement (TAVR).

METHODS
Datasets of 47 patients (35 men; 64.1 ± 10.9 years) who underwent DECT angiography of heart and vascular access prior to TAVR were reconstructed with standard linear blending (F_0.5), VMI+, and traditional monoenergetic (VMI) algorithms in 10-keV intervals from 40-100 keV. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of 564 arterial segments were evaluated. Subjective analysis was rated by three blinded observers using a Likert scale.

RESULTS
Mean SNR and CNR were highest in 40 keV VMI+ series (SNR, 27.8 ± 13.0; CNR, 26.3 ± 12.7), significantly (all p < 0.001) superior to all VMI series, which showed highest values at 70 keV (SNR, 18.5 ± 7.6; CNR, 16.0 ± 7.4), as well as linearly-blended F_0.5 series (SNR, 16.8 ± 7.3; CNR, 13.6 ± 6.9). Highest subjective image quality scores were observed for 40, 50, and 60 keV VMI+ reconstructions (all p > 0.05), significantly superior to all VMI and standard linearly-blended images (all p < 0.01).

CONCLUSIONS
Low-keV VMI+ reconstructions significantly increase CNR and SNR compared to VMI and standard linear-blending image reconstruction and improve subjective image quality in preprocedural DECT angiography in the context of TAVR planning.

KEY POINTS
• VMI+ combines increased contrast with reduced image noise. • VMI+ shows substantially less image noise than traditional VMI. • 40-keV reconstructions show highest SNR/CNR of the aortic and iliofemoral access route. • Observers overall prefer 60 keV VMI+ images. • VMI+ DECT imaging helps improve image quality for TAVR planning.
   
citation Martin S S, Albrecht M H, Wichmann J L, Hüsers K, Scholtz J E, Booz C, Bodelle B, Bauer R, Metzger S C, Vogl T J, Lehnert T. Value of a noise-optimized virtual monoenergetic reconstruction technique in dual-energy CT for planning of transcatheter aortic valve replacement. Eur Radiol 2016; 27:705-714.
   
type journal paper/review (English)
date of publishing 28-05-2016
journal title Eur Radiol (27/2)
ISSN electronic 1432-1084
pages 705-714
PubMed 27236818
DOI 10.1007/s00330-016-4422-3