Journal of cardiovascular computed tomography最新文献

Background: Calcification in a chronic total occlusion (CTO) is better visualised on Computed Tomography Coronary Angiography (CTCA) than invasive angiography.

Objectives: The authors sought to assess the characteristics of calcification of a CTO on CTCA and correlate with CTO percutaneous coronary intervention (PCI) outcome.

Methods: Retrospective analysis of the PCI database was performed (April 2017-April 2024) (clinical trials registration: NCT06414551). Patients who underwent both CTO PCI and CTCA were grouped into successful CTO PCI and any failed attempt of CTO PCI and compared for characteristics of calcification on CTCA: site of calcification, density of calcification in Hounsfield Units (HU) and quantity of calcification in % of cross section of the vessel.

Results: Out of 499 CTO PCIs performed, 82 patients had undergone CTCA. 51/82 (62.2 ​%) patients had analysable CTCAs. Mean age was 68.5 (±10.9) years and 19.6 ​% were female. Patients in the failed group were more likely to have calcification in the proximal cap (failed 65.4 ​% vs. success 24 ​%, p ​= ​0.003), more dense calcification in the proximal cap (failed: 611.8 (±517) HU vs. success: 177.6 (±356) HU; p ​= ​0.001) and proximal cap calcification quantity ≥50 ​% (failed: 75 ​% vs. success 16.7 ​%, p ​= ​0.03). Proximal cap calcification ≥50 ​% was an independent predictor of CTO PCI failure (OR, 3.21, 95 ​% CI 1.29 to 7.98, p ​= ​0.012).

Conclusions: Proximal cap calcification density and quantity on CTCA was associated with CTO PCI failure. Assessment of the proximal cap calcification may help with procedure planning in CTO PCI. Larger, prospective multicentre studies are required to corroborate these findings.

Lifetime management of aortic stenosis represents a growing procedural and clinical challenge. With recent clinical trials indicating that transcatheter aortic valve replacement (TAVR) is at least on par with surgical aortic valve replacement (SAVR) in treating lower risk patients, there has been a rise in TAVR uptake in younger, lower risk patients, leading to an increased likelihood of bioprosthetic valve degradation within a patient's lifetime. This shift in treatment has changed the landscape of interventional cardiology, incentivising the Heart Team to now plan for the initial procedure with subsequent interventions in mind. While traditional multi-slice computed tomography image-based risk assessments are sufficient for initial valve placement, they fall short in their ability to accurately predict post-procedural outcomes and future interventions. Therefore, the need to balance competing risks to optimise patient outcomes over multiple interventions requires innovation. CT-derived computational techniques are being developed to incorporate biomechanics and fluid dynamics into the risk assessment process to allow more comprehensive analysis of the risks associated with different procedures. The goal of this review is to provide an overview of computational techniques that are being developed for the purposes of optimising outcomes in both the index and valve-in-valve interventions and to give cardiologists an understanding of how they may use computational modelling as an additional tool in the lifetime management of aortic stenosis.

Background: To evaluate and compare the diagnostic performance of non-contrast, early-phase, delayed-phase images, and CT-derived extracellular volume (ECV) maps in detecting left ventricular (LV) thrombus (LVT) using cardiac computed tomography (CT).

Methods: We retrospectively analyzed 30 patients (mean age 64.3 ​± ​13.6 years) with clinically diagnosed LVT who underwent multiphase cardiac CT. Imaging protocols included non-contrast CT, coronary CT angiography (early-phase), delayed-phase CT acquired 7 ​min post-contrast, and CT-derived ECV mapping. Quantitative analysis involved measuring CT attenuation values of LVT, myocardium, and LV cavity. Two cardiovascular radiologists independently performed qualitative visual conspicuity scoring. Diagnostic performance was evaluated using receiver operating characteristic (ROC) curve analysis.

Results: Early-phase, delayed-phase, and ECV maps demonstrated significant differentiation among LVT, myocardium, and LV cavity, with ECV maps showing the highest classification accuracy. Visual conspicuity scores were also highest for ECV maps. ROC curve analysis revealed superior diagnostic performance for delayed-phase images (AUC 0.95) and ECV maps (AUC 0.98), compared with early-phase (AUC 0.78) and non-contrast images (AUC 0.55).

Conclusion: Delayed-phase imaging and CT-derived ECV mapping significantly improve the detection and characterization of LVT compared with non-contrast and early-phase CT. Incorporating these imaging techniques into cardiac CT protocols may improve diagnostic confidence and facilitate timely clinical decision-making in patients at risk of thromboembolic events.

Background: Complete coronary revascularization has significant clinical outcome implications; however, there is no objective, quantitative, or universal definition.

Aim: To provide a quantitative personalized assessment of myocardium at risk before and after coronary artery bypass grafting (CABG) surgery.

Methods: Percent left ventricular myocardial blood flow distribution (LV%MYO) was derived from coronary CT angiography (CCTA) and used to quantify the myocardium at risk of ischemia in the 16 SYNTAX coronary segments of the 114 patients in the multicenter, prospective FASTTRACK CABG trial. Given each point of the fixed SYNTAX myocardial weighting factor represents 16.7 ​% (1/6) of myocardial blood flow, the myocardial weighting factor of each coronary segment was calculated as 6 ​× ​LV%MYO. The patency of bypass grafts was assessed on 30-day follow-up CCTA, and the residual LV%MYO was obtained by subtracting the LV%MYO in segments anastomosed with non-stenotic grafts from the pre-CABG global LV%MYO.

Results: LV%MYO were analyzable in 106 patients (mean age 65.6 (8.9) years, 87 ​% male); 53 had ≥1 total occlusion. The fixed myocardial weighting factor for most SYNTAX coronary segments differs significantly from the weighting factor derived from LV%MYO. The pre-CABG global LV%MYO, and the residual LV%MYO in 96 patients with post-CABG CCTA were 70.1 (18.8)% and 14.0 (15.3)%, respectively. Complete revascularization (residual LV%MYO ≤10 ​%) was achieved in 42 patients (43.8 ​%). The operator's discretion not to graft was the main reason that 106 coronary segments were not revascularized, with graft occlusion accounting for 22.6 ​%.

Conclusion: CCTA-derived LV%MYO allows an objective and individualized quantification of the myocardium at risk, facilitating prospective prediction and retrospective assessment of the completeness of revascularization in CABG patients.

Background: Medical examiners' offices are increasingly utilizing postmortem computed tomography (CT). While dual energy CT (DECT) has been applied in both clinical and postmortem settings, research on the application to postmortem coronary computed tomographic angiography (PMcCTA) is extremely limited. This study aims to evaluate whether DECT performed following PMcCTA using two contrast agents with differing chemical and physical properties allows for agent discrimination and simultaneous characterization of coronary artery patency and myocardial perfusion.

Methods: Phantoms were created using iodine (lipophilic Angiofil, aqueous Omnipaque) and gadolinium (aqueous Dotarem) contrast agents with water dilutions of the aqueous agents, and imaged using single-source DECT. Ex vivo PMcCTA of six porcine hearts was conducted, with imaging before and serially after injection of aqueous gadolinium followed by viscous iodinated Angiofil. The hearts were then imaged using single-source DECT and SyngoVia software was used to post-process the image data.

Results: SyngoVia post-processing of DECT image data allowed for calculation of a material separation ratio of 1.7, and application of this ratio allowed discrimination between the iodinated and gadolinium agents. In the hearts, injection of Angiofil allowed for isolation of the epicardial vessels from tissue perfusion as assessed by the gadolinium which perfused the microcirculation and diffused into the extracellular space of the myocardial tissue.

Conclusion: This study demonstrates the capacity of DECT to isolate lipophilic iodinated contrast from aqueous gadolinium contrast in the setting of ex vivo PMcCTA, allowing for simultaneous characterization of vascular patency and changes in myocardial perfusion associated with vessel obstruction or infarction.