Reduction of CT artifacts from cardiac implantable electronic devices using a combination of virtual monoenergetic images and post-processing algorithms

Abstract

Objectives To evaluate the reduction of artifacts from cardiac implantable electronic devices (CIEDs) by virtual monoenergetic images (VMI), metal artifact reduction (MAR) algorithms, and their combination (VMIMAR) derived from spectral detector CT (SDCT) of the chest compared to conventional CT images (CI). Methods In this retrospective study, we included 34 patients (mean age 74.6 ± 8.6 years), who underwent a SDCT of the chest and had a CIED in place. CI, MAR, VMI, and VMIMAR (10 keV increment, range: 100–200 keV) were reconstructed. Mean and standard deviation of attenuation (HU) among hypo- and hyperdense artifacts adjacent to CIED generator and leads were determined using ROIs. Two radiologists qualitatively evaluated artifact reduction and diagnostic assessment of adjacent tissue. Results Compared to CI, MAR and VMIMAR ≥ 100 keV significantly increased attenuation in hypodense and significantly decreased attenuation in hyperdense artifacts at CIED generator and leads (p < 0.05). VMI ≥ 100 keV alone only significantly decreased hyperdense artifacts at the generator (p < 0.05). Qualitatively, VMI ≥ 100 keV, MAR, and VMIMAR ≥ 100 keV provided significant reduction of hyper- and hypodense artifacts resulting from the generator and improved diagnostic assessment of surrounding structures (p < 0.05). Diagnostic assessment of structures adjoining to the leads was only improved by MAR and VMIMAR 100 keV (p < 0.05), whereas keV values ≥ 140 with and without MAR significantly worsened diagnostic assessment (p < 0.05). Conclusions The combination of VMI and MAR as well as MAR as a standalone approach provides effective reduction of artifacts from CIEDs. Still, higher keV values should be applied with caution due to a loss of soft tissue and vessel contrast along the leads. Key Points • The combination of VMI and MAR as well as MAR as a standalone approach enables effective reduction of artifacts from CIEDs. • Higher keV values of both VMI and VMIMARat CIED leads should be applied with caution since diagnostic assessment can be hampered by a loss of soft tissue and vessel contrast. • Recommended keV values for CIED generators are between 140 and 200 keV and for leads around 100 keV.

Combination of Iterative Metal Artifact Reduction and Virtual Monoenergetic Reconstruction Using Split-Filter Dual-Energy CT in Patients With Dental Artifact on Head and Neck CT

“…Additionally, we report a high level of overcorrection at very low keV levels (40 keV), which was not included in previous reports for VMR with MAR by another vendor [18,22,33,35]. New artifacts due to MAR algorithms were less frequent compared with earlier studies [13,18,22].…”

“…Multiple studies have shown promising results when combining post-processing based MAR and dual-energy based VMR for different metal implants, mainly using spectral detector dual-energy techniques [18,22,[31][32][33][34][35]. However, the single-source split-filter DECT system used in this study is typically cheaper than scanners using other dual-energy technologies, which may improve adoption in community settings.…”

Preclinical validation of a novel deep learning‐based metal artifact correction algorithm for orthopedic CT imaging

“…Hackenbroch et al 20 . reported that VMI may lead to a lack of resolution in fine structures, while Pennig et al 21 . suggested that high keV values should be applied with caution due to the reduction in soft tissue contrast that can adversely impact diagnostic accuracy.…”

“…But, with the use of VMI image, the loss of soft tissue contrast is an inevitable compromise in order to allow assessment of adjacent soft tissue in the presence of metal implants. Hackenbroch et al 20 reported that VMI may lead to a lack of resolution in fine structures, while Pennig et al 21 suggested that high keV values should be applied with caution due to the reduction in soft tissue contrast that can adversely impact diagnostic accuracy. However, the SNRs and CNRs of AI-MAC image were not significantly different from those of the reference image.…”

Noninvasive Assessment of Lipomatous Metaplasia as a Substrate for Ventricular Tachycardia in Chronic Infarct

“…44 Metal artifact reduction algorithms are increasingly available and undergoing constant improvements. 45…”