RPS 103 - Applications of cardiac CT

Author Block: F. Castillo Aravena¹, C. Desroche², S. Delaney³, R. Nethery³, P. Thavendiranathan¹, H. Ross¹, K. Hanneman¹; ¹Toronto, ON/CA, ²Kingston, ON/CA, ³Boston, MA/US
Purpose: Both fine particulate matter (PM2.5) and nitrogen dioxide (NO2) are associated with cardiovascular mortality. However, the underlying pathophysiological mechanisms are unclear. The purpose of this study was to evaluate the relationship between long-term exposure to these air pollutants and extent of coronary artery disease.
Methods or Background: Adult patients undergoing cardiac CT between 2012-2023 were retrospectively evaluated. Coronary atherosclerosis was quantified using Agatston coronary artery calcium scores (CACS). Long-term air pollution exposures were assessed as the average of daily direct measurements of PM2.5 and NO2 in the ten-year period prior to cardiac CT. Multivariable linear regression models were adjusted for sex, age, year, distance to monitoring station, and socioeconomic status (neighborhood median household income and employment rate).
Results or Findings: 11,140 patients were included (52% male, mean age 59±11 years). Median 10-year exposure to PM2.5 was 7.5 (range 4.3–9.2) μg/m3 and NO2 was 13.4 (range 3.2-17.8) parts per billion (ppb). Each 1 µg/m3 increase in ten-year PM2.5 exposure was associated with 23.2 higher CACS (β-coefficient 23.2, 95%CI, 5.3-41.0, P=0.011) in unadjusted analysis and 19.2 higher CACS (β-coefficient 19.2, 95%CI, 0.7-37.7, P=0.042) in multivariable analysis. Each 1 ppb increase in ten-year NO2 exposure was associated with 5.0 higher CACS (β-coefficient 5.0, 95%CI, 1.9-8.2, P=0.002) in unadjusted analysis; however, this association was attenuated in multivariable analysis (β-coefficient 1.4, 95%CI, -1.7-4.4, P=0.38).
Conclusion: Higher long-term exposure to fine particulate (PM2.5) air pollution is associated with higher extent of coronary atherosclerotic disease. The relationship with NO2 was not significant in adjusted analysis. These results highlight the potential for CT to detect the sequela of long-term air pollution.
Limitations: CACS does not quantify non-calcified plaque and further study is needed to evaluate relationships with total plaque burden.
Funding for this study: None
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: University Health Network (CAPCR 24-5344)

Author Block: R. Gohmann, S. Mettke, C. F. Lücke, C. D. Krieghoff, M. Gutberlet; Leipzig/DE
Purpose: CT is a non-invasive tool for the diagnosis of coronary artery disease (CAD) and preoperative planning. However, cardiac CT (cCT) can elicit anxiety, potentially impacting patient compliance and ultimately image quality. This study investigates whether video-assisted informed consent in cardiac imaging (VAICICI) reduces patient anxiety during cCT and enhances patient understanding of the examination process.
Methods or Background: This prospective, randomized, controlled trial enrolled 205 patients scheduled for cCT. Patients were randomized into three groups: Control (n=69), Video I (n=67), and Video II (n=69). Video I was an educational video with visuals, subtitles, and voiceover explaining the examination. Video II presented only voiceover and subtitles without visuals. All patients received a standard physician consultation. Anxiety and patient satisfaction were measured using visual analog scales immediately before and after the examination. Statistical analyses included group-comparisons and multivariate-analysis to examine the influence of demographic and anamnestic variables.
Results or Findings: Both Video I and II significantly improved patient understanding, and satisfaction compared to the control group (p<0.05). Patients with Video II reported the informed consent form as more important for understanding than those in the control group (p=0.023). Satisfaction was higher after watching any video (p=0.020) with significant difference between Video I and II. Anxiety levels did not differ between the groups, though female patients (p=0.008) and those having suspected CAD reported higher pre-examination-anxiety. Overall, 10 baseline demographics were found to be partially explanatory to the response and independently statistically significant, e.g. age and previous CT/MRI-experience.
Conclusion: VAICICI improved patient satisfaction and understanding of the cCT examination. However, its impact on reported anxiety reduction was limited. The findings suggest that VAICICI enhances the informed consent process. Its influence on compliance and thus image quality remains to be investigated.
Limitations: TheSingle-centerDesignAndTheRelativelyHighFamiliarityWithImagingAmongTheStudyCohortMayLimitTheGeneralizabilityOfTheResults.
Funding for this study: None.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: ThisStudyWasApprovedByTheLocalEthicsCommittee(Reference-No.:172/22-ek).WrittenInformedConsentWasWaived.

Author Block: F. Santoro, B. La Delfa, D. Tore, C. Guarnaccia, R. Faletti, G. A. Strazzarino, C. Gaetani, A. Depaoli, P. Fonio; Turin/IT
Purpose: To evaluate the impact of Cardiac CT Angiography (CCTA) in cardiovascular risk assessment to prevent major adverse cardiovascular events (MACE) in patients undergoing diagnostic work-up before orthotopic liver transplant (OLT).
Methods or Background: Monocentric retrospective study on 140 patients with intermediate to high risk of CAD who underwent CCTA during pre-OLT diagnostic work-up at our Institution from March 2021 to October 2024.
All exams were performed using prospective ECG-gated single heartbeat axial acquisition (0.28 s gantry rotation time, kV and mA set depending on patient BMI, ECG window 40-80% of R-R cycle) with a whole-heart coverage CT scanner (Revolution CT, GE, USA).
95 patients were classified with non-critical CAD at CCTA. 23 patients with suspicion of critical CAD at CCTA underwent invasive coronary angiography (ICA).
Sensitivity, specificity, positive predicting value (PPV) and negative predictive value (NPV) were calculated.
Results or Findings: In the 95 patients with negative CCTA no one developed MACEs or cardiovascular related complications while on waiting list, nor during or after OLT; 23 patients with critical disease (CAD-RADS 4-5) at CCTA subsequently underwent ICA. In 14 cases stenosis was confirmed at ICA and patients underwent percutaneous coronary intervention (PCI) with Drug Eluting Stent (DES).
CCTA in this group of patients had 100% sensitivity, 91.3% specificity, 100% negative predicting value and 60.9% positive predicting value.
Conclusion: CCTA has an excellent diagnostic accuracy for cardiovascular risk stratification in the setting of pre-OLT work-up and it may have a role in preventing MACEs or other cardiovascular events in asymptomatic patients with intermediate to high risk of CAD.
Limitations: Monocentric study, small simple size.
Funding for this study: Nothing to discloure
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: Not applicable

Author Block: K. Mostafa, C. Wolf, C. Wünsche, S. Krutmann, M. Both, O. Jansen, H. Seoudy, P. Langguth; Kiel/DE
Purpose: The purpose of this study is the exploration of imaging biomarkers on acute phase cardiac CT that may suggest a cardioembolic etiology in patients with large vessel occlusion (LVO) stroke in patients without intracardial thrombi or atrial fibrillation in an effort to further specify and weigh the known major and minor cardioembolic risk factors.
Methods or Background: A total of 317 patients with LVO stroke and acute-setting one-step cardiac CT imaging examination were retrospectively identified and included in this study. Images were assessed for a total of 15 specific imaging findings according to known minor and major cardioembolic risk factors. Final etiology (TOAST) of LVO stroke was determined by interdisciplinary consensus after full clinical workup. Multivariate regression analysis was performed to identify cardiac imaging findings associated with a cardioembolic etiology.
Results or Findings: Overall, 221 (70%) of the LVO strokes were found to have a cardioembolic etiology by interdisciplinary consensus. After correction for atrial fibrillation and intracardiac thrombi, multivariate regression analysis defined dilatative cardiomyopathy (adjusted odds-ratio (AOR) 37.9), right-to-left shunt (AOR 21.8), valvular implants (AOR 23.7), type II and III thrombotic aortic arch (AOR 8.1) and visible myocardial scars (AOR 6.8) as risk factors for a cardioembolic etiology (AUC 0.87, p < 0.05 for all factors respectively).
Conclusion: In patients with LVO stroke without atrial fibrillation or intracardiac thrombi on acute phase cardiac CT imaging, the presence of dilatative cardiomyopathy, right-to-left shunt, valvular implants, type II and II thrombotic aortic arch and visible myocardial scars on acute phase CT imaging findings is significantly associated with a cardioembolic stroke etiology.
Limitations: This is a retrospective study with its associated limitations. The number of patients was low due to the single centre design.
Funding for this study: None.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Ethikkommission der Christian Albrechts Universität Kiel

Author Block: C. Lisi¹, K. Klambauer², L. J. Moser², V. Mergen², R. Manka², T. Flohr², M. Eberhard², H. Alkadhi²; ¹Milan/IT, ²Zürich/CH
Purpose: To investigate the influence of kernels and iterative reconstructions on pericoronary adipose tissue (PCAT) attenuation in coronary CT angiography (CCTA)
Methods or Background: Twenty subjects (16 females; median age 52 years (IQR 48-61)) with atypical chest pain and low risk of coronary artery disease (CAD) who were otherwise healthy and without evidence of CAD in photon-counting detector CCTA were included. In each subject images were reconstructed with a quantitative smooth (Qr36) and three vascular kernels of increasing sharpness levels (Bv36, Bv44, Bv56). Quantum iterative reconstruction (QIR) was either switched-off (QIR off) or was used with strengths 2 and 4. The fat-attenuation-index (FAI) of the PCAT surrounding the right coronary artery was calculated in each dataset. Histograms of FAI measurements were created. Intra- and inter-reader agreement were determined. A CT edge-phantom was used to determine the edge-spread-function (ESF) for the same datasets
Results or Findings: Intra- and inter-reader agreement of FAI were excellent (ICCs=0.99 and 0.98, respectively). Significant differences in FAI were observed depending on the kernel and iterative reconstruction strength level (each, p < 0.001), with inter-individual variation up to 34HU. FAI showed also considerable intra-individual variation (average FAI difference 19HU, maximal intra-individual difference 33HU), also depending on kernels and iterative reconstruction levels. The ESFs showed a reduced range of edge-smoothing with increasing kernel sharpness, causing FAI decrease. Histogram analyses revealed a narrower peak of PCAT values with increasing iterative reconstruction levels, causing FAI increase
Conclusion: PCAT attenuation determined with CCTA heavily depends on kernels and iterative reconstruction levels both within and across subjects. Standardization of CT reconstruction parameters is mandatory for FAI studies to enable meaningful interpretations
Limitations: Single centre study, including only healthy patients. Single vendor scanner and software analysis,
Funding for this study: No funding was received for this study
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: No additional information needed

Author Block: J. H. Lund, J. Erley, G. Adam, E. Tahir, I. Molwitz, M. Meyer; Hamburg/DE
Purpose: In 2022, the Coronary Artery Disease-Reporting and Data System (CAD- RADSTM) was updated to standardize coronary CT angiography (CCTA) reports, requiring high inter-observer reproducibility. This study aims to assess the inter-observer agreement of CAD-RADS 2.0.
Methods or Background: Patients who underwent CCTA between 2022 and 2024 using a 3rd-generation-dual-source-CT were independently evaluated by three readers with varying levels of experience (1, 3, and 12 years). CAD-RADS 2.0 was used to assess visual grading of plaque burden (P1 = mild to P4 = extensive), stenosis degree (CAD-RADS 0 = no stenosis to CAD-RADS 5 = total occlusion), and modifiers (HRP for high-risk plaque features, E for exceptions, S for stents, G for grafts, and N for non-evaluable studies). Inter-observer agreement was measured using intraclass correlation coefficients (ICC).
Results or Findings: 100 patients (29% female, age 63 ± 12 years) with a median Agatston score of 267 were included. Observers 1, 2, and 3 rated 71%, 60%, and 64% of patients, respectively, as CAD-RADS 3 or above. Inter-observer agreement for plaque burden grading (ICC:0.92, 95% CI:0.88–0.94, p < 0.001) and stenosis degree (ICC:0.88, 95% CI:0.83–0.92, p < 0.001) on a per-patient level was excellent. The agreement was also excellent on a per-vessel basis, with the highest for the left anterior descending artery (ICC:0.90) and the lowest for the left main artery (ICC:0.86). Agreement on modifiers was poor (ICC:0.06, p = 0.410).
Conclusion: CAD-RADS 2.0 demonstrates excellent inter-observer agreement for plaque burden and stenosis grading, but agreement on modifier use is low, likely due to limited use or uncertainty in their application in routine practice.
Limitations: Limited assessment of the modifiers. Experienced based-bias due to limited amount of observer, thus the real-world clinical experience might not be entirely reflected.
Funding for this study: Nothing to disclose.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was accepted by the ethics committee of the University Medial Center Hamburg-Eppendorf (UKE).

Author Block: X. Wu¹, S. Jiang², Y. Zou², T. Wang², G. Zhang², F. Huang¹, P. Liu¹, W. Sun¹, W. He¹; ¹Changsha/CN, ²Shanghai/CN
Purpose: To explore the clinical value of 60-kVp coronary CT angiography (CCTA) combined with DEep Learning Trained Algorithm (DELTA).
Methods or Background: Thirty-nine patients (20 male, 58.77 ± 16.26 years, 22.87 ± 3.71 kg/m^2) with suspected coronary artery disease (CAD) were prospectively enrolled. Each underwent both low- (60 kVp, 28 ml contrast medium at 2.5 ml/s) and routine-dose CCTA (100 kVp, 44 ml contrast medium at 4.0 ml/s) on a 320-row scanner within 2 weeks. The routine-dose data were reconstructed using hybrid iterative reconstruction (RD-HIR) and served as the reference standard. Low-dose data were reconstructed using both HIR (LD-HIR) and DELTA (LD-DELTA). Coronary stenosis in the right coronary artery (RCA), left anterior descending (LAD), and left circumflex (LCX) was assessed using CAD-Reporting and Data System (CAD-RADS) scores. The diagnostic performance of LD-HIR and LD-DELTA in distinguishing moderate (CAD-RADS<3) to severe (CAD-RADS≥3) stenosis was analyzed via receiver operating characteristic analysis. Signal-noise-ratio (SNR) and contrast-noise-ratio (CNR) on each vessel were also compared.
Results or Findings: The low-dose CCTA reduced radiation dose by 85.8% compared to the routine-dose acquisition (0.55 ± 0.09 mSv vs. 3.86 ± 1.25 mSv, p<0.001). In distinguishing moderate to severe stenosis, LD-DELTA demonstrated superior diagnostic performance compared to LD-HIR, with area under the curve (AUC) being 1.00 (95% CI, 0.91-1.00) versus 0.87 (95% CI, 0.72-0.96) in the RCA, and 1.00 (95% CI, 0.91-1.00) versus 0.78 (95% CI, 0.62-0.90) in the LCX. However, no difference was found in the LAD, with both showing an AUC of 0.98 (95% CI, 0.88-1.00). Additionally, LD-DELTA demonstrated higher SNRs and CNRs compared to LD-HIR (all p<0.001).
Conclusion: The 60-kVp low-dose CCTA acquisition with DELTA significantly reduces radiation dose while maintaining diagnostic performance for assessing coronary stenosis.
Limitations: Not applicable.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved by the local institutional review board.

Author Block: H. Wu, Y. Huang, W. Deng, Y. Wang, Q. Xiao, Y. Gu; Shanghai/CN
Purpose: This study utilized dual-layer spectral detector CT (DLCT) technology to simultaneously assess cardiac function and myocardial myocardial extracellular volume (ECV) , characterizing the changes in parameters early during breast cancer therapy.
Methods or Background: Forty female breast cancer patients who underwent postoperative adjuvant chemotherapy were prospectively enrolled and underwent baseline and 3-month-postchemotherapy cardiac CT (CCT) and ultrasound cardiography (UCG). Global ECV of the left ventricle (LV) were measured based on an iodine map of the late enhancement phase of DLCT. Changes in cardiac function parameters and global ECV from baseline to the 3-month follow-up were analyzed. Correlation coefficients between the changes in cardiac function parameters and global ECV were calculated.
Results or Findings: LV ejection fraction by UCG (UCG-LVEF) and by CCT (CCT-LVEF) did not significantly change between baseline and 3 months. Heart rate (HR) increased over 3 months of follow-up. After normalization to body surface area (BSA), cardiac output (CCT-CO indexed) and LV late (active) filling volume (LVLFV indexed) significantly increased (P<0.01), while LV early (passive) filling volume (LVEFV indexed) and LVEFV/LVLFV decreased significantly at the 3-month follow-up (P<0.05). Global ECV were elevated significantly at 3 months (25.4±2.4 vs. 27.3±2.7, P<0.01). Although changes in global ECV were not associated with changes in LVEFs, global ECV change were moderately correlated with changes in LV end-diastolic volume / BSA (CCT-LVEDV indexed) (r=0.52, P<0.01), LV stroke volume / BSA (CCT-LVSV indexed) (r=0.56, P<0.01), CCT-CO indexed (r=0.40, P=0.01) and LVEFV indexed (r=0.41, P<0.01) .
Conclusion: CCT-derived ECV can be used to evaluate myocardial changes in the early stage of chemotherapy before LVEF significantly decreases. The increases in global ECV were not correlated with LVEFs. The changes in myocardial global ECV were moderately correlated with cardiac function parameters.
Limitations: The small sample.
Funding for this study: None
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: The study was approved by the Ethics Committee of Fudan University Shanghai Cancer Center, and written informed consent was obtained from all subjects in the study.

Author Block: K. B. Dimayuga, A. Belardo, L. Perna, A. Fodor, P. Mangili, A. Del Vecchio, N. Di Muzio, C. Fiorino; Milan/IT
Purpose: Breast cancer (BC) patients undergoing radiotherapy (RT) may experience long-term cardiotoxicity. In modern series, delivering low dose to the heart, non-dosimetry predictors are emerging. The purpose was to test if cardiac calcifications (CAC) at planning CT, suggested as potential predictors, are associated with long-term cardiac events.
Methods or Background: Planning CT and clinical information of 1172 consecutive patients treated at our hospital (2009-2017) were available (right:569, left:603). The heart of all patients was automatically segmented using a previously validated AI-based tool (MIM Protegé & MIM assistant) and the mean heart dose (MHD) was assessed. CAC were automatically extracted by applying a home-made, validated, Python script extracting the Agatson score (AS) and the CAC overall volume. Their association with the risk of cardiac events was tested by logistic regression, including the potential combined effect of MHD and available clinical parameters.
Results or Findings: With a median follow-up of 8 years (range: 5-15), 32 patients experienced cardiac events. AS/CAC volumes were the most significant predictors (p<0.0001), with similar performances. Age, laterality (left/right), concomitant chemotherapy, obesity and hypertension were also significant at univariate analysis. MHD encoded using the best cut-off (1Gy, mostly representing laterality) was also predictive. The best multivariate model combined MHD>1Gy, age and CAC volume (AUC=0.79, p<0.0001, calibration plot: m=1.506, q=-0.007), being CAC volume the strongest predictor (OR: 1.0008/mm3, p<0.0001).
Conclusion: CAC load was the most important factor in cardiac risk stratification after BC RT in a modern series.
Limitations: Events are not recovered from a registry. Then, the risk of missing events is not negligible.
Funding for this study: None
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: All respected.

Author Block: H. Kato, S. Araki, S. Nakamura, A. Yamazaki, N. Kato, Y. Ichikawa, H. Sakuma, K. Kitagawa; Tsu/JP
Purpose: For patients with aortic diseases, Coronary CT angiography (CCTA) is performed for preoperative evaluation of coronary artery disease (CAD), often in combination with CT aortography (CTAO) within the same examination. However, the shared imaging field in both CCTA and CTAO results in overlapping radiation exposure to the thoracic region. Recently, a dual-source photon-counting detector CT (PCD-CT) has emerged, with its capability to perform high-pitch helical scanning to enable one-scan acquisition of CCTA and CTAO. This study aimed to compare the radiation dose and image quality of one-scan CCTA and CTAO imaging with those of separate CCTA and CTAO imaging.
Methods or Background: This study included 40 patients who underwent CCTA and CTAO for preoperative CAD screening for aortic disease: 22 had separate, 18 had one-scan CCTA and CTAO. A low tube potential of 70 or 90 kVp was used for all patients. CT dose-length product (DLP) data for CCTA and CTAO was collected. Image quality for each coronary segment and the aorta was assessed using a four-point scale (excellent, good, fair, non-diagnostic).
Results or Findings: The mean DLP was significantly lower with the one-scan CCTA and CTAO protocol (160.5±36.5 mGy*cm) compared to the separate scans (716.0±203.9 mGy*cm) (P<0.001). There was no significant difference between the separate and one-scan protocols in the assessment of image quality for CCTA (P=0.17) and CTAO (P=0.92), and in both protocols, over 95% segments/cases in the CCTA and CCAO images were rated as having good or excellent image quality.
Conclusion: PCD-CT, with high-pitch helical scanning and low tube voltage, enabled one-scan acquisition of CCTA and CTAO, significantly reducing radiation exposure while maintaining high image quality.
Limitations: There is no reference standard such as coronary angiography.
Funding for this study: No funding was provised for this study.
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: Clinical Research Ethics Review Committee of Mie University Hospital (approval No. H2019-207)