Noninvasive Imaging Research Articles

Evaluating the effects of three anesthetic regimens on retinal structure and function in the living mouse eye using a customized bimodal OCT/ORG system

Abstract Optical coherence tomography (OCT) is a non-invasive imaging technique that generates cross-sectional images of biological tissues at millimeter-level penetration depth with micron-level resolution. In this study, we developed a custom spectral-domain OCT system equipped with a flash stimulus module for dual-modality imaging of mouse retinal structure and function. The axial resolution of the system reached ∼2.7/2 μm in air/tissue following optimization and calibration. We deployed this system to conduct in vivo OCT structural imaging and optoretinography (ORG) functional assessment of mouse retina to investigate the effects of three anesthesia regimens. Statistical analysis of the results indicates that anesthesia results in a smaller relative intensity of inner/outer segment junction and external limiting membrane and a thickening of the outer segment compared to an awake state. Meanwhile, significant differences were observed in the effects on retinal structure and function between isoflurane and tribromoethanol anesthesia, while differences between isoflurane and esketamine+xylazine groups were small. These findings suggest that the type of anesthetic should be taken into account when comparing imaging results across studies reported in the literature.

Rotary excitation of non-sinusoidal pulsed magnetic fields: Towards non-invasive direct detection of cardiac conduction.

There is a need for high resolution non-invasive imaging methods of physiologic magnetic fields. The purpose of this work is to develop a MRI detection approach for non-sinusoidal magnetic fields based on the rotary excitation (REX) mechanism which was previously successfully applied for the detection of oscillating magnetic fields in the sub-nT range. The new detection concept was examined by means of Bloch simulations, evaluating the interaction effect of spin-locked magnetization and low-frequency pulsed magnetic fields. The REX detection approach was validated under controlled conditions in phantom experiments at 3 T. Gaussian and sinc-shaped stimuli were investigated. In addition, the detection of artificial fields resembling a cardiac QRS complex, which is the most prominent peak visible on a magnetocardiogram, was tested. Bloch simulations demonstrated that the REX method has a high sensitivity to pulsed fields in the resonance case, which is met when the spin-lock frequency coincides with a non-zero Fourier component of the stimulus field. In the experiments, we found that magnetic stimuli of different durations and waveforms can be distinguished by their characteristic REX response spectrum. The detected REX amplitude was proportional to the stimulus peak amplitude (R2 > 0.98) and the lowest field detection was 1 nT. Furthermore, the detection of QRS-like fields with varying QRS durations yielded significant results in a phantom setup (p < 0.001). REX detection can be transferred to non-sinusoidal pulsed magnetic fields and could provide a non-invasive, quantitative tool for spatially resolved assessment of cardiac biomagnetism. Potential applications include the direct detection and characterization of cardiac conduction.

Non-invasive Imaging Techniques for the Diagnosis of Chromoblastomycosis

Non-invasive Imaging Techniques for the Diagnosis of Chromoblastomycosis

Method for Extracting Optical Element Information Using Optical Coherence Tomography.

This study examines the measurement of film thickness, curvature, and defects on the surface or inside of an optical element using a highly accurate and efficient method. This is essential to ensure their quality and performance. Existing methods are unable to simultaneously extract the three types of information: thickness, curvature, and defects. Spectral-domain optical coherence tomography (SD-OCT), a non-invasive imaging technique with imaging depths down to the millimeter scale, provides the possibility of detecting the optical element components' parameters. In this paper, we propose an error correction model for compensating delay differences in A-scan, field curvature, and aberration to improve the accuracy of system fitting measurements using SD-OCT. During data processing, we use the histogram-equalized gray stretching (IAH-GS) method to deal with strong reflections in the thin film layers inside the optics using individual A-scan averages. In addition, we propose a window threshold cutoff algorithm to accurately identify defects and boundaries in OCT images. Finally, the system is capable of rapidly detecting the thickness and curvature of film layers in optical elements with a maximum measurement depth of 4.508 mm, a diameter of 15 × 15 mm, a resolution of 5.69 microns, and a sampling rate of 70 kHz. Measurements were performed on different standard optical elements to verify the accuracy and reliability of the proposed method. To the best of our knowledge, this is the first time that thickness, curvature, and defects of an optical film have been measured simultaneously, with a thickness measurement accuracy of 1.924 µm, and with a difference between the calibrated and nominal curvature measurements consistently within 1%. We believe that this research will greatly advance the use of OCT technology in the testing of optical thin films, thereby improving productivity and product quality.

The Story of an Egyptian Cat Mummy Through CT Examination

Much of the fascination surrounding Egyptian civilization is linked to the practice of mummification. In fact, to ensure the preservation of the body, the ancient Egyptians mummified both human and animal subjects. However, mummified animal remains are less well studied, although they represent a significant part of the material culture and history of ancient Egypt. The introduction of non-invasive imaging methods has allowed researchers to study the material hidden within the wrappings of mummies. In this article, the cat mummy currently exhibited at the Museo Etnologico Missionario di San Francesco di Fiesole (Florence, Italy), originating from Luxor and legally acquired during an expedition in the 20th century, was analyzed using computed tomography (CT). The CT enabled the identification of the casing content, showing the presence of an entire cat skeleton. The cat had several fractures, some of which were identified in the cervical region, possibly related to the cause of death. Furthermore, the zooarcheological analysis allowed the identification of the age at death of the cat, providing further information about the story of the mummy. This research provides a further contribution to the analysis of mummies, with a case study of a cat mummy that emphasizes the importance of CT scans in humanistic studies and museum environments.

Seizure Sources Can Be Imaged from Scalp EEG by Means of Biophysically Constrained Deep Neural Networks.

Seizure localization is important for managing drug-resistant focal epilepsy. Here, the capability of a novel deep learning-based source imaging framework (DeepSIF) for imaging seizure activities from electroencephalogram (EEG) recordings in drug-resistant focal epilepsy patients is investigated. The neural mass model of ictal oscillations is adopted to generate synthetic training data with spatio-temporal-spectra features similar to ictal dynamics. The trained DeepSIF model is rigorously validated using computer simulations and in a cohort of 33 drug-resistant focal epilepsy patients with high-density (76-channel) EEG seizure recordings, by comparing DeepSIF estimates with surgical resection outcome and seizure onset zone (SOZ) . These findings show that the trained DeepSIF model outperforms other methods in estimating the spatial and temporal information of origins of ictal activities. It achieves a high spatial specificity of 96% and a low spatial dispersion of 3.80±5.74mm when compared to the resection region. The source imaging results also demonstrate good coverage of SOZ, with an average distance of 10.89±10.14mm (from the SOZ to the reconstruction). These promising results suggest that DeepSIF has significant potential for advancing noninvasive imaging of the origins of ictal activities in patients with focal epilepsy, aiding management of intractable epilepsy.

Non-invasive imaging to guide percutaneous coronary revascularization in chronic total occlusion: a systematic review and meta-analysis

Abstract Background and aims Whether recanalization of coronary chronic total occlusions (CTO) leads to improved patient outcomes is uncertain. We set out to investigate the use of noninvasive imaging modalities to guide patient selection for percutaneous recanalization of coronary chronic total occlusions (CTO-PCI) and its association with outcomes. Methods Systematic review and meta-analysis of studies involving patients undergoing CTO-PCI to detail use of preprocedural non-invasive imaging, change in clinical endpoints and the occurrence of clinical events in these patient cohorts. PubMed and Embase, the Cochrane Database of Systematic Reviews, the PROSPERO database and the Clinical Trials Registry were searched for relevant randomized and observational studies up to May 2023. This study is registered with PROSPERO. The study primary endpoint was a composite of all-cause death and nonfatal myocardial infarction (MI), with a secondary composite endpoint of cardiovascular death, nonfatal MI and target vessel revascularization (TVR). Additional endpoints were individual components of the composite endpoints along with changes in angina burden, LV ejection fraction, ischemic burden, and infarct extent after PCI. Results Of 1264 publications retrieved, 31 studies (26 observational and 5 randomized) were finally included for a total of 7260 patients. Guidance to CTO-PCI varied greatly among included studies, with only a minority implementing routine preprocedural inducible ischemia and myocardial viability assessment. At a median of 3.1 years (range 1-5 years), the primary endpoint occurred at a rate of 3.1 events per 100 patient-years (95%CI: 2.4-3.7). When non-invasive imaging was used to guide CTO-PCI, patients with myocardial ischemia and/or viability, a reduced risk for the primary endpoint was observed (OR 0.3 95%CI 0.2-0.5) compared to CTO-PCI without evidence of myocardial ischemia and/or viability. CTO-PCI was associated with improvements in SAQ summary score, LVEF, reduction of ischemic burden, improvement in myocardial perfusion (all P-values &amp;lt; 0.01), with no change in the burden of myocardial scarring. At meta-regression analysis, a greater improvement in LVEF was observed in studies enrolling patients with lower average baseline LVEF (≤ 45%) (R2 = 63%, p &amp;lt; 0.0001). Conclusions CTO-PCI led to a significant improvement in symptom status (reduction of chest pain) and LV ejection fraction. CTO-PCI guided by the presence of ischemia and/or viability was associated with improved patient outcomes compared with CTO-PCI in the absence of ischemia and/viability, or in patients where non-invasive imaging testing was not performed. Future randomized clinical trials testing whether ischemia and viability-guided CTO-PCI improves clinical outcomes are lacking and warranted.PRISMA Flow diagramGraphical abstract

Number of inflamed coronary vessels in prediction of cardiac death and MACE among patients undergoing routine CCTA: the Oxford Risk Factors And Non-Invasive Imaging (ORFAN) Study

Abstract Background Coronary inflammation can be assessed by the changes in perivascular adipose tissue on routine coronary CT angiograms (CCTA). Fat attenuation index score (FAI Score) quantifies the degree of inflammation in each epicardial coronary artery, and adjusts for age, sex, scan technical parameters, biological and anatomical factors. Coronary inflammation assessment in a single coronary artery was previously shown to be predictive of cardiac events in the CRISP-CT study. However, the impact of inflammation in multiple coronary arteries on clinical outcome remains unclear. Purpose To evaluate the prognostic value of the number of inflamed coronary arteries with high inflammation in the risk of cardiac death, and major adverse cardiac events (MACE). Methods In a nested cohort within the Oxford Risk Factors And Non-invasive imaging (ORFAN) study, consecutive patients (n=3,393) who underwent routine clinical CCTA were followed up over a median(IQR) 7.7(6.4-9.1) years for cardiac mortality, and MACE (including myocardial infarction, new onset heart failure, cardiac mortality). FAI Score was calculated for each of the 3 epicardial coronary arteries. Results The number of inflamed arteries (FAI Score &amp;gt;75th centile) showed an additive impact on cardiac mortality compared with no inflamed arteries (all vessels FAI Score &amp;lt;25th centile), with hazard ratio 29.8 (95% CI 13.9-63.9, p&amp;lt;0.001) for 3 inflamed arteries, HR 20.4 (95% CI 9.4-44.7, p&amp;lt;0.001) for 2 inflamed arteries, and HR 13.0 (95% CI 5.9-28.8, p&amp;lt;0.001) for 1 inflamed artery. (Panel A) Similarly, patients with multiple inflamed arteries showed progressively higher risk for MACE (HR 7.2, 8.3 and 12.6 for 1-, 2- and 3-inflamed arteries respectively compared to patients with no inflamed artery). (Panel B) Patients with no inflamed arteries showed very low event rates for cardiac mortality and MACE. In patients with no obstructive CAD (n=2,651), similar trends were observed whereby patients with 3-inflamed arteries showed highest risk for cardiac mortality (Panel C) and MACE (Panel D), with intermediate risk for those with 1 or 2 inflamed arteries. Conclusion The number of coronary arteries with high inflammation, measured by FAI Score from routine CCTA, is associated with adverse cardiovascular events and cardiac mortality in an additive dose-response manner.

Coronary inflammation stratifies risk in patients undergoing coronary CT angiography: the Oxford Risk Factors and Non-Invasive Imaging (ORFAN) study

Abstract Background Patients with chest pain symptoms often undergo coronary CT angiography (CCTA) for the diagnosis of obstructive coronary artery disease (CAD) to guide revascularisation. However, acute cardiac events could occur in the absence of obstructive CAD. Further risk stratification of patients could potentially be useful by quantifying coronary inflammation using the Fat Attenuation Index (FAI) Score, and an artificial intelligence (AI)-assisted prognostic model that captures the inflammatory risk by integrating CCTA-derived metrics (including FAI Score and plaque burden) and the patient’s clinical risk factors. Purpose To evaluate the risk of cardiac events among patients without obstructive CAD, and the prognostic value of integrating coronary inflammation in risk stratifying this patient group. Methods From the Oxford Risk Factors and Non-invasive imaging (ORFAN) study, patients undergoing CCTA in 7 UK Hospitals (n=40,091) were followed up for the incidence of cardiac mortality over a median(IQR) of 2.7(1.4-5.3) years. In a nested cohort of 3,393 patients with long-term follow up, we evaluated the long-term prognostic value of FAI Score and the performance of AI-Risk algorithm over a median(IQR) follow up of 7.7(6.4-9.1) years. Reclassification of risk category from AI-Risk was compared with contemporary clinical risk score (QRISK3). Results Patients without obstructive CAD (n=32,533, 81.1%) accounted for 63.7% of all cardiac deaths (n=1,754) during follow up, highlighting the substantial proportion of cardiac events in absolute terms given a large proportion of patients without obstructive CAD. In the nested cohort with long-term follow up, FAI Score in any of the 3 epicardial coronary arteries was significantly associated with cardiac mortality with or without obstructive CAD. In the whole cohort, the highest quartile of FAI Score in LAD showed 20-times higher risk of cardiac death compared with the lowest quartile (Panel A). Integrating coronary inflammation with clinical risk factors and plaque burden, patients with very-high AI-Risk classification showed 6-fold higher risk of cardiac mortality compared to low/medium risk, with good alignment of the incident predicted events from AI-Risk and observed events. (Panel B) The predicted cardiac mortality from AI-Risk also demonstrated good calibration with the observed events in the whole population. (Panel C) Finally, AI-Risk significantly reclassify the risk above clinical risk factor-based prediction (QRISK3) (Panel D). Conclusion Patients with high coronary inflammation measured by FAI Score showed significantly elevated risk for cardiac mortality. The AI-enabled absolute risk prediction algorithm leads to significant reclassification of patients undergoing routine CCTA, and can be used as a precision medicine tool.

AI-enhanced detection of coronary inflammation predicts 10-year risk for cardiac mortality and MACE in individuals with no or minimal coronary atherosclerosis on routine CCTA

Abstract Background Coronary CT angiogram (CCTA) is one of the first line investigations for patients with chest pain suspected of coronary artery disease (CAD). Current CCTA interpretations mainly focus on luminal obstruction, which is identified in the minority of patients, whereas the majority who have no or minimal atherosclerotic plaques visible on CCTA are often provided with reassurance. However, residual risk from inflammation that drives atherosclerosis and plaque vulnerability are not captured with luminal stenoses alone. Fat attenuation index (FAI) Score quantifies coronary inflammation on routine CCTA, and integrate with clinical risk factors/plaque burden in an artificial intelligence enabled risk algorithm (AI-Risk) that could help to risk stratify this patient group. Purpose To evaluate the prognostic value or FAI Score and AI-Risk in the risk stratification of patients with no or minimal atherosclerosis. Methods In a nested cohort within the Oxford Risk Factors and Non-invasive imaging (ORFAN) study, consecutive patients (n=3,393) who underwent routine clinical CCTA were followed up over a median(IQR) 7.7(6.4-9.1) years for cardiac mortality and major adverse cardiac events (MACE, including myocardial infarction, new onset heart failure, cardiac mortality). CADRADS 2.0 classification 0 or 1 were used to define no or minimal luminal stenoses. FAI Score was calculated for each of the 3 epicardial coronary arteries. Results A total of 1,678 patients had no or minimal atherosclerosis on CCTA [median (IQR) age 53(45-63), 49.8% male]. Cardiac mortality occurred in 3.1% and MACE occurred in 8.8% of the patients during the follow-up period. Patients at the lowest quartile of FAI Score or low/medium AI-Risk classification showed very low event rate during follow up. Patients with the highest quartile of LAD FAI Score showed 9 times higher risk of cardiac mortality (Panel A) and 5 times higher risk of MACE (Panel B) compared to those at lowest quartile. Similar findings were observed for LCX and RCA. Finally, integrating coronary inflammation with clinical risk factors and plaque burden, patients at very high AI-Risk classification showed 5 times higher risk of cardiac mortality (Panel C), and 4 times higher risk of MACE (Panel D) compared to those with low/medium risk classification. Conclusion Coronary artery inflammation measured by FAI Score could stratify the risk of patients with no or minimal coronary atherosclerosis on CCTA, and could help to guide early preventative treatments.

Sex differences in clinical characteristics, phenotypes, management, and long-term outcomes of myocardial injury: an international cohort study

Abstract Background Several studies have demonstrated sex differences in patients presenting to the emergency department (ED) with myocardial infarction, heart failure or syncope. Whether sex-specific differences in chest pain patients with myocardial injury exist is unknown. Purpose To determine whether sex-specific differences in the clinical characteristics, phenotypes, management, and long-term outcomes of patients with myocardial injury exist. Methods Patients presenting to the ED with chest pain suggestive of MI were consecutively enrolled into a prospective multicenter international diagnostic study. Final diagnoses were centrally adjudicated by two independent cardiologists, applying the fourth universal definition of myocardial infarction, using all available medical records, including serial hs-cTn and cardiac imaging. Follow-ups were performed at 3 months, 1-, 2- and 5-years. The primary outcome was 5-year all-cause mortality. Secondary outcomes included 5-year cardiovascular mortality and non-cardiovascular mortality. Multivariable flexible parametric (Royston-Parmar) models assuming proportional hazards were fitted. Models were adjusted for age, history of coronary artery disease, history of malignancy, diabetes, hypertension, smoking status, history of liver disease, and renal function. Results Among 8046 chest pain patients presenting to the ED, 1158 (14.4%) had myocardial injury, of which 358 (31%) were females and 800 (69%) males. Women were older (79 years, vs. 73 years), had fewer cardiovascular risk factors and comparable non-cardiovascular comorbidities except for lung disease which was more commonly found in men. Myocardial injury phenotypes varied between sexes (Figure). The most common phenotype in both sexes was heart failure, yet it was more common in men (37.2%) than in women (22.3%). The second most common phenotype in women was hypertension (15.4%) and arrhythmia (15.4 %), while in men was myocarditis (17.8 %), followed by arrhythmia (15.8%). Women underwent less invasive coronary angiography (19.8% vs 26.9%) or stress testing (12% vs 21.5%). In the angiographic findings, women presented more often with normal findings (30.4% vs. 19.6%) or mild CAD (20.3% vs. 11.2%) whereas men displayed more frequently 3-vessel disease (14.5% vs. 36.4%), Table. After adjusting for known confounders, women were associated with a lower 5-years risk for all-cause mortality (HR 0.69; 95%CI: 0.56–0.83) and cardiovascular mortality (HR 0.61; 95%CI: 0.46–0.79). No statistically significant difference in non-cardiovascular mortality risk was found (HR 0.79; 95%CI: 0.59-1.04). Conclusions Women presenting with chest pain to the ED and having myocardial injury were less likely than men to undergo coronary angiography or non-invasive cardiac imaging. Long-term risk for all-cause or cardiovascular mortality was lower for women compared to men.Myocardial Injury phenotypesPatient management

The diagnostic value of endomyocardial biopsy in the era of precision medicine: data from over 8,000 patients with comprehensive biopsy diagnostics

Abstract Background Endomyocardial biopsy (EMB) is an important diagnostic tool for evaluating various cardiac diseases such as myocarditis and storage disorders as well as for the monitoring heart transplant patients. Despite advances in non-invasive imaging techniques to characterize myocardial tissue, EMB remains the gold standard for definitive diagnosis and initiation of specific therapy. Here we report EMB laboratory results from over 8,000 patients and demonstrate the diagnostic utility of EMB. Methods and results We retrospectively reviewed EMB analyses performed at our institution. EMBs for monitoring graft rejection were not included in this study. Clinical data, suspected clinical diagnoses and EMB-based laboratory results were collected. Histopathological, immunohistochemical and molecular biology biopsy findings were recorded and reviewed for degree of concordance with clinical diagnosis. In total, EMBs from N=8,085 consecutive patients with unexplained heart failure were analyzed. The comprehensive EMB analysis revealed that N=616 (7.6%) patients had cardiac storage disease, most of whom had cardiac amyloidosis (N=606). N=357 (4.4%) patients were diagnosed with acute forms of myocarditis, including N=95 cases with active myocarditis, N=148 cases with giant cell myocarditis, N=95 cases with sarcoidosis and N=19 cases with eosinophilic myocarditis. A total of N=3,392 (42%) patients were found to have inflammatory heart disease such as inflammatory cardiomyopathy and borderline myocarditis, whereby a differentiation of the inflammatory infiltrates revealed considerable differences in the quality of inflammation. Viral genomes were found in the myocardium of N=6,072 (75%) patients, with treatment-relevant viral infections detected in N=2,015 (25%) cases. The remaining N=1,705 (21%) patients were diagnosed with other cardiomyopathies, including dilated cardiomyopathy (N=1,252), heart failure with preserved ejection fraction (N=325), hypertrophic cardiomyopathy (N=117) and arrhythmogenic right ventricular cardiomyopathy (N=11). Conclusions This retrospective study of over 8,000 patients with heart failure clearly shows that a definitive diagnosis is only possible with a comprehensive EMB diagnosis and leads to specific therapy in 79% of the cases. In the remaining 21% of patients, infectious and inflammatory causes could be excluded in order to initiate standard heart failure therapy. It is important to emphasize here that the quality of the inflammation and therapy-relevant viral infections cannot be detected with imaging techniques, which underlines the clinical-therapeutic importance of endomyocardial biopsy.

A novel device for electrocardiographic imaging

Abstract Background Electrocardiographic imaging (ECGi) is a non-invasive imaging tool that allows 3D visualization and characterization of the electrical activity of the heart from measurements on the body surface by solving the so called "inverse problem of electrocardiography". This method helps overcome the limitations of the conventional12-lead ECG in diagnosing and locating heart arrythmias. We developed a textile 34-electrode imageless device (with no need for MRI or CT-scan). Purpose We aim to evaluate the feasibility and safety of the use of a novel textile imageless 34-electrode device for recording ECGi for identification of electrical activity of the heart. Methods and results The performance of a prototype data acquisition system (DAS) was evaluated in 158 individuals. Tests were conducted in three hospitals. The mean age was 43.32 years old (±17.44); mean height 167.31cm (±18.33); mean weight 70kg (±15.68). Almost 88% of the patients were in sinus rhythm. The relative frequencies of the targeted pathologies are listed in Figure 1. The collection of cardiac signals and posterior representation in virtual reality of a stereoscopic, holographic 3D-360º map, was achieved in 100% of the patients. Figure 2 shows the textile hardware with the silver dry electrodes and a screenshot of the software with an example of a voltage map in a patient in sinus rhythm. There were no adverse effects reported. The DAS is composed of 34 electrodes, being their distribution representative of the electrical activity on the torso. Several studies have discussed the minimum number of electrodes on the torso of the patient required to characterize the heart potentials from the electrical potentials on the torso surface through the inverse problem (1,2). We highlight that the representativeness condition of the electrical activity on the torso is crucial to appropriately estimate cardiac activity with the minimum number of leads on the DAS. Conclusion The use of a novel textile imageless 34-electrode device for recording ECGi for identification of electrical activity of the heart is feasible and safe.Targeted rhythmHardware and software

Repeatability, Reproducibility, and Observer Variability of Cortical T1 Mapping for Renal Tissue Characterization.

The global rise in kidney diseases underscores the need for reliable, noninvasive imaging biomarkers. Among these, renal cortical T1 has shown promise but further technical validation is still required. To evaluate the repeatability, reproducibility, and observer variability of kidney cortical T1 mapping in human volunteers without known renal disease. Prospective. Three cohorts without renal disease: 1) 25 volunteers (median age 38 [interquartile range, IQR: 28-42] years, female N = 11) for scan-rescan assessments on GE 1.5 T and Siemens 1.5 T; 2) 29 volunteers (median age 29 [IQR: 24-40] years, female N = 15) for scan-rescan assessments on Siemens 3 T; and 3) 16 volunteers (median age 34 [IQR: 31-42] years, female N = 8) for cross-scanner reproducibility. 1.5 T and 3 T, a modified Look-Locker imaging (MOLLI) sequence with a balanced steady-state free precession (bSSFP) readout. Kidney cortical T1 data was acquired on GE 1.5 T scanner, Siemens 1.5 T and 3 T scanners. Within-scanner repeatability and inter/intra-observer variability: GE 1.5 T and Siemens 1.5 T, and cross-scanner manufacturer reproducibility: Siemens 1.5 T-GE 1.5 T. Bland Altman analysis, coefficient of variation (CoV), intra-class coefficient (ICC), and repeatability coefficient (RC). Renal cortical T1 mapping showed high repeatability and reliability across scanner field strengths and manufacturers (repeatability: CoV 1.9%-2.8%, ICC 0.79-0.88, pooled RC 73 msec; reproducibility: CoV 3.0%, ICC 0.75, RC 90 msec). The method also showed robust observer variability (CoV 0.6%-1.4%, ICC 0.93-0.98, RC 22-48 msec). Kidney cortical T1 mapping is a highly repeatable and reproducible method across MRI manufacturers, field strengths, and observer conditions. 2 TECHNICAL EFFICACY: Stage 2.

Aortic integral distensibility based on the auto-segmented dynamic motion of the aortic wall

Abstract Background Aortic stiffness is important in cardiovascular diseases and predicting outcomes. Echocardiography is a widely used noninvasive imaging modality for assessing aortic stiffness, but its accuracy can be limited by the low spatial resolution of ultrasound-based images and the subjectivity of manual measurements of aortic dimensions. Automated segmentation analysis can provide a more accurate and objective measure. Objective An automated algorithm and software have been developed for segmenting the aortic wall. A new measurement technique called "Aortic Integral Distensibility (AID)" has been formulated using this framework. This method overcomes limitations of traditional method focusing solely on the two positions of Aortic Distensibility (AD). Method In this particular investigation, 112 participants were subjected to echocardiography in order to quantify the dynamics of the aortic wall. An automated algorithm was devised to delineate the aortic wall by utilizing an M-mode echocardiography scan. The statistical analysis encompassed the measurement of AD and AID before and after the age of 65 group. This analysis was conducted considering various risk factors, including age, gender, weight, BMI, smoking, and blood pressure. Additionally, clinical parameters, specifically AIx @75 (Augmentation Index) and Framingham Risk Score (FRS), were evaluated as well. Inter-rater reliability was conducted between the traditional AD and the newly implemented AID. Results The results indicate that the group under 65 had more distensibility than the group over 65, and AID measurements were slightly higher than AD measurements. SBP showed a strong correlation with AID, rather than AD. AIx @75 and FRS had a negative relationship with distensibility. In the 65 years or older group, there was a significant negative correlation observed between AIx @75 and AID (r = -0.4, p = 0.012). Furthermore, a strong correlation was also observed between FRS and AID (r = -0.53, p = 0.002). Bland-Altman analysis demonstrated that the automated methodology had better reproducibility and less variability in distensibility measurements than the manual methodology. Conclusion The study suggests that AID could be valuable for assessing aortic stiffness. AID could help clinicians diagnose and manage cardiovascular diseases more accurately. The automatic approach provides reliable measurements for aortic distensibility and strain, which has clinical implications.Schematic Chart of the Study Process

Diagnostic performance of the fragmented QRS complex on electrocardiogram for detecting myocardial scars assessed by 3.0 Tesla cardiac magnetic resonance imaging

Abstract Background Fragmented QRS complex (f-QRS) on a 12-lead electrocardiogram (EKG) with a 100 Hz low-pass filter is known to be related to ischemic myocardial scars. Cardiac magnetic resonance (CMR) imaging enhances tissue characterization capability resulting in a better myocardial scar assessment over other noninvasive imaging modalities. However, the diagnostic values of f-QRS on non-ischemic scars and f-QRS from EKG with a 40 Hz low-pass filter (routine filter in clinical practice) are unknown. Therefore, this study aims to evaluate the diagnostic performance of f-QRS (from EKG with 40 Hz and 100 Hz low-pass filters) for detecting any myocardial scars assessed by 3.0 Tesla CMR. Methods This cross-sectional study included patients who underwent a 3.0 Tesla CMR scan from May 2020 to May 2023. A 12-lead EKG with 0.15-40 and 0.15-100 Hz low-pass filters, performed on the same day of the CMR scan, was assessed for the presence of f-QRS. The ECG leads were divided into 3 categories (e.g., anteroseptal leads V1-V4; lateral leads I, aVL, V5-V6; and inferior leads II, III, aVF). The f-QRS was defined as the presence of R’ wave or notching in the nadir of the S wave in 2 contiguous leads. The primary outcome was the diagnostic performance of f-QRS from EKG in myocardial scar detection in the corresponding left ventricle (LV) segments. The secondary outcomes were to compare diagnostic performance between f-QRS from EKG with 0.15-40 and 0.15-100 Hz low-pass filters. Results The study involved 1,692 participants with a median age of 67 (IQR: 59-85) years old and 52.5% males. Myocardial scars were found in 826 (49%) participants. Male, history of CAD, and myocardial scars were significantly more frequent in the participants with f-QRS (59.4% vs 46%, 26.4% vs 20.6%, and 48.9% vs 37.3%, respectively). The sensitivity, specificity, positive predictive value, negative predictive value, and AUC of f-QRS from EKG with 0.15-100 Hz low-pass filter for detecting myocardial scars were 25.6%, 88.7%, 45.1%, 76.8%, and 0.57 for anteroseptal segments; 22.1%, 91.5%, 36.8%, 84.1%, and 0.57 for lateral segments; and 42.9%, 63.4%, 36.9, 68.9%, and 0.53 for inferior segments. The f-QRS from 0.15-100 Hz showed a higher sensitivity but lower specificity and PPV for all LV segments. NPV and AUC were not significantly different between the two filters. Conclusion This study demonstrates a high specificity and negative predictive value of f-QRS from a 12-lead EKG with 0.15-40 and 0.15-100 Hz low-pass filters in diagnosing myocardial scars when correlated to the corresponding LV segments.central illustrationbaseline charateristic

Gender differences in the use of coronary computed tomography angiography, functional testing, coronary angiography, revascularization, and outcomes - a 10-year Danish, nationwide, registry-based foll

Abstract Background and aims Coronary computed tomography angiography (CCTA) serves as a noninvasive imaging modality, that guides downstream preventive and invasive treatment. However, differences in its use in relation to gender has not been investigated. Methods This nationwide register-based cohort study investigated all residents in Denmark between 2008 and 2018, consisting of individuals aged 50-80 years without coronary artery disease (CAD). The study population was stratified into male and female cohorts (n = 1469724). The outcomes included CCTA, functional testing, invasive coronary angiography (ICA), myocardial infarction (MI), revascularization, and major adverse cardiovascular and cerebrovascular events (MACCE). Results Among individuals who underwent CCTA, a slightly higher use was observed among females (absolute risk [AR] 4.2% individuals aged ≥50-59 years, AR 4.1% individuals aged ≥60-69 years, and AR 2.3% individuals aged ≥70-80 years) compared to males (absolute risk [AR] 4.0% individuals aged ≥50-59 years, AR 3.6% individuals aged ≥60-69 years, and AR 2.3% individuals aged ≥70-80 years). Conversely, the use of functional testing, were lower among females (AR 4.5% individuals aged ≥50-59 years, AR 5.2% individuals aged ≥60-69 years, and AR 4.3% individuals aged ≥70-80 years) compared to males (AR 6.2% individuals aged ≥50-59 years, AR 7.1% individuals aged ≥60-69 years, and AR 6.3% individuals aged ≥70-80 years), similar differences were observed for ICA, revascularization, MI risks, and MACCE. Conclusion Men were less likely to undergo CCTA compared to women. Conversely, use of functional testing, ICA, and revascularization along with an increased risk of MI or MACCE were higher in men.Figure 1

Predictive value of plaque characteristics assessed by coronary computed tomography angiography and optical coherence tomography for identification of lesions causing ischemia

Abstract Background In patients with intermediate coronary stenosis, the functional assessment with fractional flow reserve (FFR) and the anatomical assessment with optical coherence tomography (OCT) have been widely used in clinical practice. Additionally, coronary computed tomography angiography (CTA) is commonly used non-invasive imaging technique for evaluating suspected coronary artery disease before being referred for angiography. Objectives This study sought to investigate the association between FFR and plaque characteristics assessed by coronary CTA and OCT in intermediate coronary stenosis. Methods Based on the prospective multicentre registry, a total of 159 patients including 339 coronary lesions with intermediate stenosis were included. All patients underwent coronary CTA before being referred for coronary angiography and both FFR measurement and OCT examination were performed during angiography. The stenotic lesion with FFR ≤0.80 was considered diagnostic of lesion causing ischemia. The predictive value of plaque characteristics assessed by coronary CTA and OCT for identifying lesions causing ischemia was analyzed. Results Stenosis severity and plaque characteristics on coronary CTA and OCT were different between the lesions causing ischemia versus not causing ischemia. On multivariate analysis, low attenuation plaque on coronary CTA (odds ratio [OR]= 2.78; P=0.038) and thrombus (OR=5.13; 0.042), plaque rupture (OR=3.25; P=0.017), and intimal vasculature on OCT (OR=2.57; P=0.012) were independent predictors for the lesions causing ischemia. Increasing number of these plaque characteristics offered incremental improvement in predicting the lesions causing ischemia. Conclusions Comprehensive anatomical evaluation of coronary stenosis may be able to provide additional supportive information for predicting the lesions causing ischemia.

Multiple Arterial Aneurysms Revealing a New Case of Ehlers-Danlos Syndrome

Ehlers-Danlos syndrome (EDS) is a rare genetic disorder transmitted in an autosomal dominant mode. Its progression in young adults is marked by vascular, digestive, and obstetric complications. We report the case of a 24-year-old woman presenting with a mass in the right femoral triangle. Non-invasive imaging revealed multiple staged arterial aneurysms in the lower limbs. The diagnosis of vascular Ehlers-Danlos syndrome was established based on facial dysmorphia, acrogeria, and a history of right humeral aneurysm surgery. The patient underwent surgery for the right femoral aneurysm due to its significant size and risk of rupture, with simple monitoring for the other arterial aneurysms that were discovered incidentally. The postoperative course was uneventful with a favorable outcome.

Echo triaging works. How to use international guidelines

Abstract Introduction Transthoracic echocardiography (TTE) is the first-choice non-invasive imaging modality for the assessment of cardiac structure and function due to its wide availability, speed, cost-effectiveness and reproducibility. Therefore, there is exponential increase in demand in TTE across all specialties in medicine and surgery. Hence, it is important to carefully triage patients according to current international guidelines. Purpose To reduce inappropriate TTE scans by using guideline driven indications in triaging echo scans in the UK tertiary hospital. Methods Strict list of guidelines driven indications adapted to local practice was used for triaging echo requests which included both inpatient and outpatient TTEs. The 4 objectives: appropriateness, completeness of requests as well as impact of performed studies on the follow-up and patient management plan were assessed before and after implementation of new triaging tool. To ensure similar working and staff environment was sustained we studied the pattern of referrals in the same month of the year- September. The triage process was conducted by accredited physiologists. The same month was chosen to reflect true change of practice. Change in patient management and follow up were evaluated for a minimum duration of 6-months. Results Overall there were 1112 TTEs performed in September 2022 and 1081 - in September 2023. Prospective TTE referral triaging began in March 2023. We have studied and analyzed above criteria retrospectively. In 2022 there were 18% inappropriate requests; 37% of requests lacked sufficient clinical information and 10% of studies did not lead to change in management plan according to clinical letters. There was also high proportion of inappropriate requests for inpatients (9%). Within 6 months of implementation there was a significant improvement in the appropriateness (82% vs. 99%, p&amp;lt;0.001), with increase in supply of adequate clinical information (63.4% vs. 86.1%, p&amp;lt;0.001). However, there was no significant change using TTE study results in changing patient management (10%). All inpatients had 100% appropriate requests. Conclusion The implementation of triage criteria resulted in a significant improvement in TTE referrals: both in appropriateness and completeness of requests. However, some clinicians did not use echo in patient management plan. Future research on lack of use of TTE results in clinical practice might help to utilize the limited echo capacity to full.