Aug 2026· Journal of thoracic imaging· 0 citations· 31 references
Medicine
TL;DR
Aortic Valve Calcium Score obtained on VNC images from DECT examinations is a promising method for noninvasively differentiation between severe and nonsevere aortic stenosis, which could be potentially useful in patients who have undergone examinations for noncardiac indications.
Abstract
STUDY TYPE
Retrospective monocentric study.
Purpose
To estimate the probability of severe aortic stenosis(SAS) by calculating the aortic valve calcium score (AVCS) using virtual noncontrast (VNC) reconstructions derived from non-ECG-gated dual-energy computed tomography (DECT) scans.
Materials And Methods
This study retrospectively included 59 patients who underwent DECT scans for noncardiac indications and presented with visible aortic valve calcifications. AVCS was calculated on VNC images using semiautomatic software. All patients had an echocardiogram performed within 12 months before or after the DECT scan. We then analyzed the correlation between AVCS values and the degree of aortic stenosis.
Results
Both male and female patients with SAS had a significantly higher mean AVCS (919.2 AU, SD=1262.4) compared with those with nonsevere aortic stenosis (NSAS) (127.9 AU, SD=278.6). AVCS demonstrated good diagnostic performance in distinguishing between severe and nonsevere AS in both female and male (AUC=0.91 and 0.95, respectively). Estimated thresholds values showed high sensitivity in both genders, with good specificity in men, and moderate in women. When analyzed irrespective of gender, AVCS demonstrated good ability to distinguish severe AS from mild and no stenosis (AUC=0.926), and moderate ability to distinguish moderate AS from mild and no stenosis (AUC=0.781). However, it lacked statistical significance in discriminating severe and moderate AS (AUC=0.714, P=0.1325).
Conclusions
Aortic Valve Calcium Score obtained on VNC images from DECT examinations is a promising method for noninvasively differentiation between severe and nonsevere aortic stenosis, which could be potentially useful in patients who have undergone examinations for noncardiac indications.
With the growing use of delayed dual-energy computed tomography (DECT) imaging for extracellular volume assessment, this study aimed to assess the accuracy of coronary artery calcium (CAC) and aortic valve calcification (AVC) quantification in virtual non-contrast (VNC) images derived from delayed DECT images. Eighty-eight patients undergoing pre-transcatheter aortic valve replacement (TAVR) cardiac CTA with DECT were retrospectively enrolled. We compared CAC score (CACS), CAC volume, AVC score (AVCS), and AVC volume between true non-contrast (TNC) and VNC images. VNC images were created by subtracting iodine from delayed CT angiography using commercial post-processing software. Concordance for the likelihood of severe aortic stenosis (AS) between TNC and VNC was assessed using guideline-based AVCS thresholds: men > 3,000 AU, women > 1,600 AU (highly likely); men > 2,000 AU, women > 1,200 AU (likely). CACS was lower in VNC than TNC (363.0 [13.7-1,154.0] AU vs. 470.1 [46.8-1,569.9] AU, p < 0.001), but the correlation was excellent (r = 0.966). No significant difference between VNC and TNC was observed in AVCS (959.5 [321.2-2,475.0] AU vs. 1,079.6 [492.2-2,329.4] AU, p = 0.521), with strong correlation (r = 0.966). Application of a correction factor (1.1-fold) improved agreement between VNC- and TNC-derived CACS (weighted κ = 0.839 to 0.869). Diagnostic concordance for severe AS between VNC and TNC was 92.1% (weighted kappa = 0.785) at the "highly likely" threshold and 97.7% (weighted kappa = 0.952) at the "likely" threshold. Delayed VNC images from DECT demonstrate strong agreement with TNC images for CACS and AVCS, suggesting that delayed VNC could potentially reduce the need for TNC acquisition in pre-TAVR assessment.
H. Fujito, K. R. Bookani, B. Gheyath et al.· The International Journal of...· 0 citations
CT-derived AVA demonstrates strong agreement with TTE and provides complementary information for severity assessment and risk stratification in patients with aortic stenosis, particularly in cases with discordant or borderline findings.
Shehroz Sultan, Neeraj Joshi, A. H. Awan et al.· Journal of Community Hospita...· 0 citations
Higher HU thresholds did not outperform conventional 130-HU scoring and showed only modest, comparable performance for within-severity hemodynamic stratification, and should be interpreted as complementary densitometric analyses rather than alternative diagnostic cut-offs.
Michael Welt, M. Alnees, Yazan Hamdan et al.· The International Journal of...· 0 citations
OBJECTIVE
Coronary artery disease (CAD) is prevalent in patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve implantation (TAVI). Computed tomography-derived fractional flow reserve (CT-FFR) may provide non-invasive functional assessment using existing TAVI planning imaging to evaluate CT-FFR diagnostic performance compared with invasive coronary angiography (ICA) for identifying functionally significant CAD in TAVI candidates.
METHODS
This single-centre retrospective study included 37 patients with severe AS undergoing TAVI (June 2016-June 2023). All underwent pre-procedural coronary CT angiography and ICA. CT-FFR was retrospectively analysed using deep learning-based software (threshold < 0.81 for significant stenosis). Diagnostic performance was assessed per-vessel (52 coronary arteries) using ICA as reference standard.
RESULTS
Mean age was 79.2 ± 8.4 years; 56.7% were male. ICA identified significant CAD in 14 patients (37.8%), involving 21 lesions. CT-FFR successfully analysed all 52 vessels in the final cohort (mean value 0.86 ± 0.11) identifying 20 lesions (38.4%) as functionally significant; however, 8 of 62 initially screened patients (12.9%) were excluded due to insufficient CT image quality, reflecting a relevant limitation of clinical feasibility. CT-FFR demonstrated sensitivity 80.9% (95% CI: 58.1%-94.6%), specificity 93.5% (95% CI: 78.6%-99.2%), positive predictive value 85.0%, negative predictive value 90.6%, and diagnostic accuracy 88.5%. No significant difference existed between CT-FFR and ICA classifications (p > 0.05). At 30 days, no deaths, myocardial infarctions, or strokes occurred.
CONCLUSION
CT-FFR provides good diagnostic performance for detecting haemodynamically significant CAD in TAVI candidates. Integration into routine workflows may reduce purely diagnostic invasive procedures while maintaining accuracy. Larger prospective studies are needed to validate these findings.
Soner Aksüyek, F. Koca, Abdulsamet Arslan et al.· Cardiovascular Journal of Af...· 0 citations
PURPOSE
To compare coronary artery calcium (CAC) scores from ultra-low-dose true non-contrast (TNC), virtual non-contrast (VNC), and virtual non-iodine (VNI) images with standard TNC on a dual-source photon-counting detector CT (PCD-CT).
METHODS
In this prospective single-center study (January 2025-March 2026), patients underwent standard TNC (sequential, 120 kVp), ultra-low-dose TNC (high-pitch helical, tin-filtered 100 kVp), and coronary CT angiography (CCTA); VNC and VNI images were generated from CCTA. CAC scores and burden categories were evaluated. Correlation and agreement with standard TNC were assessed using Pearson coefficients with Williams' test, Bland-Altman plots, and weighted Cohen's kappa.
RESULTS
Seventy-one patients (median age, 75 years; 52 men) were evaluated. Median dose-length product was 7.98, 71.8, and 428 mGy cm for ultra-low-dose TNC, standard TNC, and CCTA, respectively. Ultra-low-dose TNC showed the strongest correlation with standard TNC (r = 0.996), superior to VNI (r = 0.976, P < 0.001) and VNC (r = 0.900, P < 0.001). Agreement in CAC burden categorization was excellent for ultra-low-dose TNC (κ = 0.932) and good for VNI (κ = 0.827), whereas VNC showed moderate agreement (κ = 0.424). VNI had minimal bias (mean difference, -3.9) but wider limits of agreement than ultra-low-dose TNC (-356.5 to 348.6 vs. -163.2 to 105.9). VNC underestimated CAC scores (mean bias, -442.0).
CONCLUSION
Ultra-low-dose TNC with dual-source PCD-CT showed excellent agreement with standard TNC while reducing radiation by nearly 90%. VNI was acceptable but less robust, whereas VNC substantially underestimated CAC scores. Ultra-low-dose TNC is a reliable, dose-efficient alternative to standard TNC for CAC scoring.
S. Araki, S. Nakamura, M. Deguchi et al.· Journal of cardiovascular co...· 0 citations
A broad spectrum of etiologies can lead to aortic wall thickening. This study aimed to evaluate the utility of quantitative parameters derived from dual-layer computed tomography (CT) in differentiating intramural hematoma (IMH), non-calcified plaques, and aortic thrombosis, and to explore their associations with laboratory inflammatory markers.
365 patients were retrospectively enrolled, including atherosclerosis (
n
= 98), aortic dissection (
n
= 126), and IMH (
n
= 141). Laboratory indicators were collected from the electronic medical record system. Regions of interest (ROI) of non-calcified plaques, thrombi, hematomas, and periaortic adipose tissue around lesions were outlined. The lesion enhancement values and degree of enhancement were calculated from the CT values in polyenergetic and virtual non-contrast image. The slope of the energy spectrum curve was determined using the formula: K = (CT
40keV
- CT
100keV
) / 60. Normalization was performed for the effective atomic number (Z), iodine density (ID), and iodine non-water density (IW) using the aortic lumen as the standard reference, resulting in normalized Z values, normalized iodine density (NID), and normalized iodine non-water density (NIW).
The enhancement values and degrees of enhancement differed among the three lesions (all
P
< 0.05). Differences in Z value, ID, IW, and K were observed among non-calcified plaques, thrombi, and hematomas (all
P
< 0.05). The NID of hematoma was the largest, while the NIW of thrombus was the smallest. Normalized Z value of non-calcified plaque was significantly smaller than those of thrombus and hematoma (both
P
< 0.05), with no difference between thrombus and hematoma (
P
> 0.05). The Z
periaortic fat
pre- and post-normalization were significantly smaller around the plaques than around the thrombi and hematomas (both
P
< 0.05). Significant correlations were found between aortic wall normalized Z
lesion
, Z
periaortic fat
, and laboratory parameters, including neutrophil % and neutrophil count, lymphocyte % and lymphocyte count, C-reactive protein, and D-dimer.
Quantitative spectral CT parameters show promise for the non-invasive identification of aortic wall lesions. The weak correlations with laboratory inflammatory markers suggest a potential but limited link between imaging parameters and local inflammation. These exploratory findings require further validation. If confirmed in future studies, this approach may complement conventional CTA and guide targeted therapy.
Not applicable.
Na Li, Jia Liu, Qinyue Luo et al.· BMC Medical Imaging· 0 citations
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