Effect of Virtual Monoenergetic Images From Spectral Detector Computed Tomography on Coronary Calcium Blooming

Abstract

Objective The aim of this study was to investigate the quantitative and qualitative effects of virtual monoenergetic images (VMI) by spectral detector computed tomography (SDCT) on calcium blooming in coronary computed tomography angiography. Methods Coronary computed tomography angiography using SDCT was performed on 42 patients with coronary artery calcifications. Stenosis grading by diameter and area of calcified plaques and free lumen using VMI from 70 to 140 keV was performed and compared with measurements by conventional images. In addition, interobserver reliability and subjective image quality were assessed by 2 experienced readers. Results A total of 61 coronary arteries were evaluated. Stenosis grading by diameter and area showed significant incremental decrease, from 48.86% to 22.82% and from 41.18% to 11.33%, respectively, with increasing VMI (P < 0.05). Interobserver reliability was excellent (intraclass correlation coefficient >0.99). Overall image quality was best at 80 keV. Conclusions Calcium blooming significantly decreases at higher monoenergetic levels from SDCT, increasing luminal dimensions and decreasing stenotic grading, with best overall subjective image quality using 80-keV VMI.

Improved coronary artery contrast enhancement using noise-optimised virtual monoenergetic imaging from dual-source dual-energy computed tomography

“…Hickethier et al confirmed these observations also for dual-layer DECT [29]. High-keV VMI/VMI + reconstructions are also able to reduce blooming artifacts from calcified coronary plaque [30]. This technique can be further extended to DECT-based advanced calcium subtraction which also results in improved reader confidence [31].…”

Incidental Finding of Secondary Tumoral Calcinosis Following Cardiothoracic Surgery: The Role of Multimodality Imaging Including Spectral Detector Computed Tomography

“…The projection data simultaneously obtained from both detector layers can also be utilized to generate various diagnostically useful spectral images, including, virtual monoenergetic images (display tissue attenuation properties similar to those resulting from imaging with a mono-energetic beam at a single energy level and virtual unenhanced images (tissue decomposition is used to remove iodine content from an image to produce a no iodine image). The exponential dependence on the atomic number (Z4) and proximity of iodine’s K-edge (approximately 33 keV) results in increased contrast in low-energy VMIs (VMIlow) on contrast-enhanced CT scans [ 2 - 4 ].…”

Manual kidney stone size measurements in computed tomography are most accurate using multiplanar image reformatations and bone window settings

“…Besides the importance of low-dose, non-contrast CT as the imaging modality of choice in suspected urolithiasis; a more recent innovation, dual-energy CT (DECT) demonstrated its beneficial value in the imaging of urolithiasis enabling an increased material separation. DECT allows for reconstruction of virtual monoenergetic images which are known to reduce blooming of calcified structures and may impact size measurements 26 . Furthermore, DECT provides additional information about kidney stone composition, which may be exploited with regards to treatment decision making 7 , 27 .…”