Modified Dual-Energy Algorithm for Calcified Plaque Removal

Mannil, Manoj; Ramachandran, Jaychandran; Martini, Isabella; Wegener, Susanne; Schmidt, Bernhard; Flohr, Thomas; Krauß, Bernhard; Valavanis, A; Alkadhi, Hatem; Winklhofer, Sebastian

doi:10.1097/rli.0000000000000391

Cited by 54 publications

(22 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Several CTA limitations (e.g. the “blooming” artifact of calcifications) are well-known [ 42 ], but there seems to be a widespread absence of understanding that the “numeric” outcome of CTA evaluation of carotid stenosis severity, reported as “% stenosis”, may be largely dependent on the calculation method used ( Figure 2 ).…”

Section: Discussionmentioning

confidence: 99%

“…Secondly, lesion ulceration(s) and calcification(s) affect the differences between CTA and cQA visualization as well as the CTA-AS vs. cQA-DS measurement of stenosis severity [ 19 ]. In calcified plaques, conventional CTA determination of stenosis severity, particularly at higher stenosis grades, may be hampered by blooming artifacts (present in up to 90% of calcified arteries [ 42 ]), resulting in an overestimation of the actual stenosis grade [ 42 ]. In addition dense calcium deposits may cause streak and beam hardening artifacts [ 42 ], impeding the accurate diagnosis of stenosis severity.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Misclassification of carotid stenosis severity with area stenosis-based evaluation by computed tomography angiography: impact on erroneous indication to revascularization or patient (lesion) migration to a higher guideline recommendation class as per ESC/ESVS/ESO/SVS and CMS-FDA thresholds

Tekieli¹,

Mazurek²,

Dzierwa³

et al. 2022

pwki

View full text Add to dashboard Cite

Intoduction Despite a growing understanding of the role played by plaque morphology, the degree of carotid lumen reduction remains the principle parameter in decisions on revascularization in symptomatic and asymptomatic patients. Computed tomography angiography (CTA) is a widely used guideline-approved imaging modality, with “percent stenosis” commonly calculated as %area reduction (area stenosis – AS). Aim We evaluated the impact of the non-linear relationship between diameter stenosis (DS) and AS (area = π • (diameter/2) 2 , so that in concentric lesions 51%AS is 30%DS and 75%AS is 50%DS) on stenosis severity misclassification using calculation of area reduction. Material and methods CTA and catheter quantitative angiography (cQA) were performed in 300 consecutive patients referred to a tertiary vascular centre for potential carotid revascularization (age: 47–83 years, 33.7% symptomatic, 36% female; referral stenosis of ≥ “50%”). CTA-AS was determined by agreement of 2 experienced radiologists; cQA-DS (pivotal trials standard reference, NASCET method) was calculated by agreement of 2 corelab analysts. Results For symptomatic lesion thresholds, CTA-AS-based calculation reclassified 76% of “< 50%” cQA-DS measurements to the “50–69%” group, and 58% of “50–69%” measurements to the “≥ 70%” group. For asymptomatic lesion thresholds, 78% of “< 60%” cQA-DS measurements were reclassified to the “60–79%” group, whereas 42% of “60–79%” cQA measurements crossed to the “≥ 80%” class. Overall, employing CTA-AS instead of cQA-DS enlarged the “60–79%” and “≥ 80%” lesion severity classes 1.6- and 5.8-fold, respectively, whereas the “≥ 70%” class increased 4.15-fold. Conclusions Replacing the pivotal carotid trials reference standard cQA-DS “%stenosis” measurement with CTA-AS-based “%stenosis” results in a large-scale lesion/patient erroneous gain of an “indication” to revascularization or migration to a higher revascularization indication class. In consequence, unnecessary carotid procedures may be performed in the absence of cQA verification. Until guidelines rectify the “%stenosis” measurement methods with different guideline-approved imaging modalities (and, where needed, re-adjust decision thresholds), CTA-AS measurement should not be used as a basis for carotid revascularization.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Misclassification of carotid stenosis severity with area stenosis-based evaluation by computed tomography angiography: impact on erroneous indication to revascularization or patient (lesion) migration to a higher guideline recommendation class as per ESC/ESVS/ESO/SVS and CMS-FDA thresholds

Tekieli¹,

Mazurek²,

Dzierwa³

et al. 2022

pwki

View full text Add to dashboard Cite

show abstract

“…In this context, VNCa imaging has been shown to improve the quantification of carotid artery stenoses caused by hard plaques compared to conventional CTA, using digital subtraction angiography as reference [95]. Moreover, lumen assessment did not show to be impacted by blooming artifacts, probably because the algorithm recognizes and removes the spectral behavior of calcium blooming components [95].…”

Section: Vascular Applicationsmentioning

confidence: 99%

“…DECT algorithms are well known to improve image quality, to reduce the contrast medium volume and the radiation dose to patients undergoing CTA studies [6, . DECT-based three-material decomposition also allows for subtraction of the calcium signal from iodinated vessels, permitting the removal of hard plaques from a CTA scan [95].…”

Section: Vascular Applicationsmentioning

confidence: 99%

Virtual non-calcium dual-energy CT: clinical applications

et al. 2021

View full text Add to dashboard Cite

Dual-energy CT (DECT) has emerged into clinical routine as an imaging technique with unique postprocessing utilities that improve the evaluation of different body areas. The virtual non-calcium (VNCa) reconstruction algorithm has shown beneficial effects on the depiction of bone marrow pathologies such as bone marrow edema. Its main advantage is the ability to substantially increase the image contrast of structures that are usually covered with calcium mineral, such as calcified vessels or bone marrow, and to depict a large number of traumatic, inflammatory, infiltrative, and degenerative disorders affecting either the spine or the appendicular skeleton. Therefore, VNCa imaging represents another step forward for DECT to image conditions and disorders that usually require the use of more expensive and time-consuming techniques such as magnetic resonance imaging, positron emission tomography/CT, or bone scintigraphy. The aim of this review article is to explain the technical background of VNCa imaging, showcase its applicability in the different body regions, and provide an updated outlook on the clinical impact of this technique, which goes beyond the sole improvement in image quality.

show abstract

“…In light of neuroimaging, dual-energy CT demonstrated improved image quality and lesion characterization, while it also allowed material separation for iodine. 15,[17][18][19][20][21][22] Dual-energy CT systems register low-and high-energy data attenuation profiles. By linear blending of these datasets, VMI can be reconstructed.…”

mentioning

confidence: 99%

Virtual Monoenergetic Images from Spectral Detector CT Enable Radiation Dose Reduction in Unenhanced Cranial CT

Reimer

Flatten

Lichtenstein

et al. 2019

AJNR Am J Neuroradiol

View full text Add to dashboard Cite

BACKGROUND AND PURPOSE: Our aim was to evaluate whether improved gray-white matter differentiation in cranial CT by means of 65-keV virtual monoenergetic images enables a radiation dose reduction compared to conventional images. MATERIALS AND METHODS: One hundred forty consecutive patients undergoing 171 spectral detector CTs of the head between February and November 2017 (56 6 19 years of age; male/female ratio, 56%/44%) were retrospectively included. The tube currenttime product was reduced during the study period, resulting in 61, 55, and 55 patients being examined with 320, 290, and 260 mAs, respectively. All other scanning parameters were kept identical. The volume CT dose index was recorded. ROIs were placed in gray and white matter on conventional images and copied to identical positions in 65-keV virtual monoenergetic images. The contrastto-noise ratio was calculated. Two radiologists blinded to the reconstruction technique evaluated image quality on a 5-point Likert-scale. Statistical assessment was performed using ANOVA and Wilcoxon test adjusted for multiple comparisons.

show abstract

Modified Dual-Energy Algorithm for Calcified Plaque Removal

Cited by 54 publications

References 20 publications

Misclassification of carotid stenosis severity with area stenosis-based evaluation by computed tomography angiography: impact on erroneous indication to revascularization or patient (lesion) migration to a higher guideline recommendation class as per ESC/ESVS/ESO/SVS and CMS-FDA thresholds

Misclassification of carotid stenosis severity with area stenosis-based evaluation by computed tomography angiography: impact on erroneous indication to revascularization or patient (lesion) migration to a higher guideline recommendation class as per ESC/ESVS/ESO/SVS and CMS-FDA thresholds

Virtual non-calcium dual-energy CT: clinical applications

Virtual Monoenergetic Images from Spectral Detector CT Enable Radiation Dose Reduction in Unenhanced Cranial CT

Contact Info

Product

Resources

About