Background and Objectives: Coronary sinus oxygen saturation is a useful indicator of health and disease states. However, it is not routinely used in clinical practice. Cardiovascular magnetic resonance imaging (CMR) oximetry can accurately estimate oxygen saturation in the pulmonary artery. This research aimed to provide a method for calculating coronary sinus oxygen saturation (ScsO₂) from pulmonary artery oxygen saturation (SpaO₂) that could be applied to CMR. Materials and Methods: A systematic literature review was conducted to identify prior work that included invasive measures of ScsO₂ and either SpaO₂ or right ventricular oxygen saturation. This revealed one study with appropriate data (ScsO₂ and SpaO₂ measurements, n = 18). We then carried out agreement and correlation analyses. Results: Regression analysis demonstrated a statistically significant, positive relationship between ScsO₂ and SpaO₂, giving a regression equation of ScsO₂ = −31.198 + 1.062 × SpaO₂ (r = 0.76, p < 0.001). A multivariable regression analysis of all reported variables, excluding SpaO₂, independently identified superior vena cava oxygen saturation (SsvcO₂) and arterial oxygen saturation (SaO₂) as predictors of ScsO₂ (r = 0.78, p < 0.001), deriving the equation ScsO₂ = −452.8345 + 4.3579 × SaO₂ + 0.8537 × SsvcO₂. Conclusions: In this study, we demonstrated a correlation between coronary sinus oxygen saturation and pulmonary artery oxygen saturation, allowing the estimation of ScsO₂ from SpaO₂. This association enables the estimation of ScsO₂ from purely CMR-derived data. We have also described a second model using arterial and superior vena cava saturation measurements, providing an alternative method. Future validation in larger, independent cohorts is needed.

Background: Left atrial (LA) assessment is an important marker of adverse cardiovascular outcomes. Cardiovascular magnetic resonance (CMR) accurately quantifies LA volume and function based on biplane long-axis imaging. We aimed to validate single-plane-derived LA indices against the biplane method to simplify the post-processing of cine CMR. Methods: In this study, 100 patients from Leeds Teaching Hospitals were used as the derivation cohort. Bias correction for the single plane method was applied and subsequently validated in 79 subjects. Results: There were significant differences between the biplane and single plane mean LA maximum and minimum volumes and LA ejection fraction (EF) (all p < 0.01). After correcting for biases in the validation cohort, significant correlations in all LA indices were observed (0.89 to 0.98). The area under the curve (AUC) for the single plane to predict biplane cutoffs of LA maximum volume ≥ 112 mL was 0.97, LA minimum volume ≥ 44 mL was 0.99, LA stroke volume (SV) ≤ 21 mL was 1, and LA EF ≤ 46% was 1, (all p < 0.001). Conclusions: LA volumetric and functional assessment by the single plane method has a systematic bias compared to the biplane method. After bias correction, single plane LA volume and function are comparable to the biplane method.

Background: Left ventricular filling pressure (LVFP) is pivotal in heart failure management, yet non-invasive assessment remains challenging. While echocardiography is the first line, cardiovascular magnetic resonance (CMR) offers enhanced accuracy. This study evaluates the interplay between CMR-derived LVFP and echocardiography, focusing on sex differences and correlations with N-terminal pro-brain natriuretic peptide (NT-proBNP). Methods: In this prospective study, 222 patients with CMR-derived LVFP > 14 mmHg underwent transthoracic echocardiography (TTE) and CMR. Sex-specific CMR equations (incorporating left atrial volume and ventricular mass) were used to estimate pulmonary capillary wedge pressure (PCWP). Correlations between imaging parameters and NT-proBNP were assessed. Results: CMR-derived LVFP showed no sex-based differences (p = 0.3143), unlike echocardiographic indices: women had higher E/e′ (p < 0.0001) and lower lateral mitral annular velocities (p = 0.0159). CMR-derived LVFP correlated strongly with NT-proBNP (r = 0.47, p < 0.0001), outperforming E/e′ (r = 0.41). Stratification by CMR PCWP tertiles revealed higher NT-proBNP (p = 0.0003), left atrial volumes (p < 0.0001), and septal thickness (p < 0.0001) in the highest tertiles. CMR-derived LVFP demonstrated superior diagnostic accuracy (AUC = 0.754 vs. 0.740 for E/e′) in identifying elevated NT-proBNP (>400 pg/mL). Sex-independent CMR measures contrasted with echocardiography, where parameters like left atrial volume varied by sex (p = 0.012). Conclusions: CMR-derived LVFP is a robust, sex-independent biomarker strongly linked to NT-proBNP, offering superior diagnostic performance over echocardiography. Its integration with echocardiographic indices enhances the non-invasive assessment of cardiac filling pressures, advocating a synergistic imaging approach to refine heart failure management.

Background and Objectives: Chronic total occlusion (CTO) affects 30% of patients undergoing coronary angiography rendering poorer outcomes. While percutaneous coronary intervention (PCI) can be technically successful, RCTs show no survival benefit. Cardiovascular Magnetic Resonance (CMR) provides comprehensive myocardial phenotyping, offering prognostic insights in this high-risk cohort. Materials and Methods: Fifty-six patients with angiographically confirmed CTO underwent stress perfusion CMR with late gadolinium enhancement. Myocardial function, ischaemia and scar burden were quantified and compared across CTO territory and viability subgroups. Results: In patients with CTO, 27% of patients (15/56) had no viability. In patients with viable myocardium, 66% (27/41) demonstrated reversible ischaemia. Viable myocardium was associated with significantly higher LV stroke volumes (93.6 ± 20.1 mL vs. 80.9 ± 18.4 mL, p = 0.039), along with lower LV scar mass (18.7 ± 13.5g vs. 32.3 ± 12.8g; p = 0.002) and scar percentage (14.9 ± 8.3% vs. 25.9 ± 7.5%; p = 0.001). Viable myocardium showed more ischaemia both globally (11.6 ± 14.3g vs. 0.2 ± 9.3g; p = 0.005) and within the CTO territory (10.3 ± 10.3% vs. 2.3 ± 2.7%; p = 0.01). Non-viable myocardium was associated with significantly higher CTO-territory scar mass (9.4 ± 6.5 g vs. 5.1 ± 6.9 g; p = 0.046) and scar percentage (21.8 ± 13.3% vs. 11.7 ± 12.8%; p = 0.01), indicating extensive fibrosis. A scar burden threshold of 11.18% in CTO territory predicted non-viability with 80% sensitivity and 65.85% specificity (AUC = 0.701 [95% CI 0.54–0.87], p = 0.019). Conclusions: Among CTO patients, 27% harbour no viability, while patients with viable myocardium typically exhibit reversible ischaemia—representing a phenotype with preserved viability and inducible ischaemia. These findings support the use of multiparametric CMR to phenotype CTO territories prior to considering CTO-PCI.

Four-dimensional (4D) flow cardiovascular magnetic resonance assesses advanced haemodynamic parameters like kinetic energy (KE), vorticity, and viscous energy loss (vEL). However, gradient-based metrics (vorticity, vEL) are highly sensitive to partial volume effects near the fluid–tissue boundary. This study investigated the impact of systematic contour boundary offsets on these parameters to standardise analysis. Five cases underwent 4D flow imaging. Deep learning-derived automated segmentations of the cardiac chambers were generated. Haemodynamics were analysed using three contouring methods: the baseline mask, a one-voxel inward offset, and a two-voxel inward offset. KE, vorticity, and vEL decreased progressively with larger offsets. KE declined modestly with erosion (by approximately 18% and 35% at one- and two-voxel offsets, respectively), a reduction commensurate with the loss of integration volume rather than the removal of boundary artefacts. By contrast, the gradient-based metrics were disproportionately sensitive to boundary proximity. In the left ventricle, mean full-cycle vorticity decreased from 249.6 ± 79.9 s⁻¹ (baseline) to 157.0 ± 60.4 s⁻¹ (two-voxel offset; Hedges’ g 2.11), whilst vEL decreased from 549.4 ± 303.0 µW to 351.3 ± 230.0 µW (Hedges’ g 2.00). A one-voxel inward offset optimally reduces boundary noise for sensitive gradient-based parameters. While KE analysis remains satisfactory using unmodified baseline contours, we recommend the uniform application of a one-voxel offset across all parameters to ensure methodological simplicity and pipeline standardisation.