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Background Stereotactic arrhythmia radioablation (STAR) is a promising non-invasive therapy for patients with ventricular tachycardia (VT). Accurate identification of the arrhythmogenic volume, or clinical target volume (CTV), on the radiotherapy (RT) 4D planning computed tomography (CT) scan is key for STAR efficacy and safety. This case report illustrates our workflow of electro-structural image integration for CTV delineation. Case summary A 72-year-old man with ischaemic cardiomyopathy and VT storm, despite two (endocardial and epicardial) catheter-based ablations, was consented for STAR. A 3D electro-structural arrhythmia model was generated from co-registered electroanatomical voltage and activation maps, electrocardiographic (ECG) imaging, and the cardiac CT angiography scan (in ADAS 3D), pinpointing the VT isthmus and inferoapical VT exit. At this location, an area with short recovery times was found with ECG imaging. A multidisciplinary team delineated the CTV on the transmural ventricular myocardium, which was fused with the 4D planning CT scan using a digital images and communication in medicine (DICOM) radiotherapy file. The CTV was 63% smaller compared with using the conventional American Heart Association 17-segment approach (11 vs. 24 cm3). A single fraction of 25 Gy was delivered to the internal target volume. After an 8-week blanking period, no VT recurrences or radiation-related side-effects were noted. Eight months later, the patient died from end-stage heart failure. Discussion We report a novel workflow for 3D-targeted and ECG imaging-aided CTV delineation for STAR, resulting in a smaller irradiated volume compared with segmental approaches. Acute and intermediate outcome and safety were favourable. Non-invasive ECG imaging at baseline and during induced VT holds promise for STAR guidance. [ABSTRACT FROM AUTHOR]

Ventricular tachycardia (VT) is a life-threatening heart rhythm and has long posed a complex challenge in the field of cardiology. Recent developments in advanced imaging modalities have aimed to improve comprehension of underlying arrhythmic substrate for VT. To this extent, high-resolution cardiac magnetic resonance (CMR) and cardiac computed tomography (CCT) have emerged as tools for accurately visualizing and characterizing scar tissue, fibrosis, and other critical structural abnormalities within the heart, providing novel insights into VT triggers and substrate. However, clinical implementation of knowledge derived from these advanced imaging techniques in improving VT treatment and guiding invasive therapeutic strategies continues to pose significant challenges. A pivotal concern lies in the absence of standardized imaging protocols and analysis methodologies, resulting in a large variance in data quality and consistency. Furthermore, the clinical significance and outcomes associated with VT substrate characterization through CMR and CCT remain dynamic and subject to ongoing evolution. This highlights the need for refinement of these techniques before their reliable integration into routine patient care can be realized. The primary objectives of this study are twofold: firstly, to provide a comprehensive overview of the studies conducted over the last 15 years, summarizing the current available literature on imaging-based assessment of VT substrate. Secondly, to critically analyze and evaluate the selected studies, with the aim of providing valuable insights that can inform current clinical practice and future research.

Accurately estimating gross primary production (GPP) in terrestrial ecosystems is crucial for gaining a deeper understanding of the carbon cycle within the ecosystem and for predicting climate change. Although many GPP datasets are available, they often have low resolution, typically around 500 m or lower, which restricts their effectiveness in monitoring fragmented croplands and areas with high heterogeneity. In this study, we utilized optical satellite data from Landsat-8/9 and Sentinel-2A/B, along with meteorological data from ERA5, to generate a GPP dataset with a spatial resolution of 30 m for three provinces in Northeast China. This dataset was developed based on the Vegetation Photosynthesis Model and exhibited robust validation results when compared with SIF data and other existing GPP datasets. It provides a high-resolution GPP product that significantly enhances the precision of carbon cycle research in Northeast China. This research underscores the feasibility of producing high spatial resolution GPP products using Landsat-8/9 and Sentinel-2A/B optical satellite data. The resulting dataset offers a more refined GPP estimate for studies related to the terrestrial carbon cycle.

Early crop mapping is essential in predicting crop yield, assessing agricultural disasters, and responding to food price fluctuations. Winter wheat is a major food contributor in China. Existing early season maps of winter wheat strongly depend on the shape of the time series curve, which limits applicability on large scales. Besides, the effect of garlic on winter wheat mapping is often ignored. In this study, we determined how early we could identify winter crops (winter wheat and garlic) by examining time series of different lengths, and generated annual 30-m winter wheat and garlic map of the Huaihe basin using the random forest classifier, Sentinel-1/2, and Landsat-7/8 time-series imagery. The results showed that garlic could be identified at the end of November by using four composite images with an overall accuracy (OA) of 0.88, followed by winter wheat recognizable at the end of January by using eight composite images with an OA of 0.91. The proposed framework can also be implemented in other regions and crops to generate early season distribution maps of different crops.

Aims The goal of this case series was to evaluate the feasibility, safety, and advantages of a wire-based approach for the live visualization of coronary arteries (CAs) in an electroanatomic mapping (EAM) system and to assess its diagnostic information. Methods and results For this single-centre case series, we included procedures in which close proximity of a possible ablation site to any epicardial vessel was suspected. An uncoated-tip guidewire was introduced into the relevant CAs after exclusion of critical CA stenosis by coronary angiography. By connecting this wire to the EAM system using a clip and pin connection, mapping and live visualization of the wire tip is possible, as well as the assessment of the local electrograms within the respective CAs. Procedural wire insertion and intracoronary mapping was performed by EP specialists and was assisted to judge the relevance of CA disease by an interventional cardiologist. A total of nine procedures in nine patients were included in this case series, four ventricular tachycardia ablation procedures and five procedures for the ablation of premature ventricular contractions. The left CAs were mapped in eight cases and the right CA was mapped in one case. In two cases, epicardial mapping was combined with visualization of the right or left CAs. There were no complications attributed to coronary wiring and mapping in this case. Conclusion We demonstrated the feasibility and safety of CA visualization and integration in an EAM. The live visualization of the CAs added valuable information without the need for preprocedural planning or the purchase of separate software. Electroanatomic visualization was achieved intraprocedurally in a safe and straightforward manner, adding critical diagnostic information without excessive costs or risks. [ABSTRACT FROM AUTHOR]

Mass spectrometry imaging (MSI) is used in many aspects of clinical research, including pharmacokinetics, toxicology, personalised medicine, and surgical decision-making. Maximising its potential requires the spatial integration of MSI images with imaging data from existing clinical imaging modalities, such as histology and MRI. To ensure that the information is properly integrated, all contributing images must be accurately aligned. This process is called image registration and is the focus of this review. In light of the ever-increasing spatial resolution of MSI instrumentation and a diversification of multi-modal MSI studies (e.g., spatial omics, 3D-MSI), the accuracy, versatility, and precision of image registration must increase accordingly. We review the application of image registration to align MSI data with different clinically relevant ex vivo and in vivo imaging techniques. Based on this, we identify steps in the current image registration processes where there is potential for improvement. Finally, we propose a roadmap for community efforts to address these challenges in order to increase registration quality and help MSI to fully exploit its multi-modal potential.

IntroductionPatients with ventricular tachyarrhythmias (VT) are at high risk of sudden cardiac death. When appropriate, catheter ablation is modestly effective, with relatively high VT recurrence and complication rates. Personalized models that incorporate imaging and computational approaches have advanced VT management. However, 3D patient-specific functional electrical information is typically not considered. We hypothesize that incorporating non-invasive 3D electrical and structural characterization in a patient-specific model improves VT-substrate recognition and ablation targeting.Materials and methodsIn a 53-year-old male with ischemic cardiomyopathy and recurrent monomorphic VT, we built a structural-functional model based on high-resolution 3D late-gadolinium enhancement (LGE) cardiac magnetic resonance imaging (3D-LGE CMR), multi-detector computed tomography (CT), and electrocardiographic imaging (ECGI). Invasive data from high-density contact and pace mapping obtained during endocardial VT-substrate modification were also incorporated. The integrated 3D electro-anatomic model was analyzed off-line.ResultsMerging the invasive voltage maps and 3D-LGE CMR endocardial geometry led to a mean Euclidean node-to-node distance of 5 ± 2 mm. Inferolateral and apical areas of low bipolar voltage (0.4) and with higher transmurality of fibrosis. Areas of functional conduction delay or block (evoked delayed potentials, EDPs) were in close proximity to 3D-LGE CMR-derived heterogeneous tissue corridors. ECGI pinpointed the epicardial VT exit at ∼10 mm from the endocardial site of origin, both juxtaposed to the distal ends of two heterogeneous tissue corridors in the inferobasal left ventricle. Radiofrequency ablation at the entrances of these corridors, eliminating all EDPs, and at the VT site of origin rendered the patient non-inducible and arrhythmia-free until the present day (20 months follow-up). Off-line analysis in our model uncovered dynamic electrical instability of the LV inferolateral heterogeneous scar region which set the stage for an evolving VT circuit.Discussion and conclusionWe developed a personalized 3D model that integrates high-resolution structural and electrical information and allows the investigation of their dynamic interaction during arrhythmia formation. This model enhances our mechanistic understanding of scar-related VT and provides an advanced, non-invasive roadmap for catheter ablation.

Recently, there has been an increase in the automation of complex technological processes in various industries, which is caused by the need to increase production efficiency. Since non-destructive testing (NDT) has become an integral part of many industries, this trend is also observed in it. The obtained image containing information about the condition and quality of the object is the final result of the majority of testing methods. Therefore, automation of processing and analysis of received images is an urgent task for NDT today. The purpose of this article is to review image-processing technologies based on data integration and to consider the prospects of applying these methods to solving the problems of thermal NDT. The article describes the main theoretical principles of image fusion technology, considers the classification of fusion methods, and various modern methods of image fusion of different levels with their pros and cons. Various methods based on spatial data and transformations with quality metrics and their application in various fields were also discussed. In addition, the application of the technology of fusion in the problems of image formation during implementation of the thermal tomography method is considered. The following steps are proposed for the study of the use of fusion in the problems of materials diagnosis. 61 Ref. [ABSTRACT FROM AUTHOR]

ABSTRACT Background: We aimed to describe the morphology of the border zone of viable myocardium surrounded by scarring in patients with Chagas heart disease and study their association with clinical events. Methods: Adult patients with Chagas heart disease (n=22; 55% females; 65.5 years, SD 10.1) were included. Patients underwent high-resolution contrast-enhanced cardiac magnetic resonance using myocardial delayed enhancement with postprocessing analysis to identify the core scar area and border zone channels number, mass, and length. The association between border zone channel parameters and the combined end-point (cardiovascular mortality or internal cardiac defibrillator implantation) was tested by multivariable Cox proportional hazard regression analyses. The significance level was set at 0.05. Data are presented as the mean (standard deviation [SD]) or median (interquartile range). Results: A total of 44 border zone channels (1[1-3] per patient) were identified. The border zone channel mass per patient was 1.25 (0.48-4.39) g, and the extension in layers of the border zone channels per patient was 2.4 (1.0-4.25). Most border zone channels were identified in the midwall location. Six patients presented the studied end-point during a mean follow-up of 4.9 years (SD 1.6). Border zone channel extension in layers was associated with the studied end-point independent from left ventricular ejection fraction or fibrosis mass (HR=2.03; 95% CI 1.15-3.60). Conclusions: High-resolution contrast-enhanced cardiac magnetic resonance can identify border zone channels in patients with Chagas heart disease. Moreover, border zone channel extension was independently associated with clinical events.

Abstract Background The purpose of this meta‐analysis was to evaluate the impact of image integration technique on clinical and procedural outcomes in patients undergoing radiofrequency catheter ablation of atrial fibrillation with a three‐dimensional electroanatomic mapping system. Methods Randomized controlled trials were identified through a systematic literature search of PubMed and CENTRAL databases from inception to April 2020. The primary outcome was arrhythmia recurrence during the follow‐up period. The secondary outcomes were the difference in total procedural time and fluoroscopy time. Results Four studies with a total of 749 patients were included. The pooled result showed no statistically significant difference between the groups with respect to arrhythmia recurrence (RR, 0.75; 95% CI, 0.47‐1.21), fluoroscopy time (MD, −6 minutes; 95% CI, −23.4 to 11.3), and total procedural time (MD, 1.1 minutes; 95% CI, −31.8 to 34.1). Conclusion Image integration to guide radiofrequency catheter ablation for patients with atrial fibrillation does not improve clinical and procedural outcomes.

Recently, three-dimensional (3D) facial scanning has been gaining popularity in personalized dentistry. Integration of the digital dental model into the 3D facial image allows for a treatment plan to be made in accordance with the patients' individual needs. The aim of this study was to evaluate the effects of extraoral markers on the accuracy of digital dentofacial integrations. Facial models were generated using smartphone and stereophotogrammetry. Dental models were generated with and without extraoral markers and were registered to the facial models by matching the teeth or markers (n = 10 in each condition; total = 40). Accuracy of the image integration was measured in terms of general 3D position, occlusal plane, and dental midline deviations. The Mann–Whitney U test and two-way analysis of variance were used to compare results among face-scanning systems and matching methods (α = 0.05). As result, the accuracy of dentofacial registration was significantly affected by the use of artificial markers and different face-scanning systems (p < 0.001). The deviations were smallest in stereophotogrammetry with the marker-based matching and highest in smartphone face scans with the tooth-based matching. In comparison between the two face-scanning systems, the stereophotogrammetry generally produced smaller discrepancies than smartphones. [ABSTRACT FROM AUTHOR]

Copyright of Herzschrittmachertherapie und Elektrophysiologie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: We present a case series and short review of electroanatomical mapping (EAM)–guided pacing lead implantation. The cases illustrate different aspects of EAM use in special circumstances and summarizes our experience with EAM-guided His lead implantation in 32 consecutive patients. Advantages and caveats encountered when using EAM in device procedures are discussed. Objective: To illustrate usefulness of EAM-guided lead implantation and computed tomography (CT) image integration in a case series. Methods: Lead implantation was performed targeting different anatomically defined regions using EAM for mapping and lead navigation, as well as using the system for image integration for 2 cardiac resynchronization therapy implantations. Results: For His bundle pacing lead implantation, a steep learning curve for successful His bundle lead placement seems obtainable (91%) for new implanters using EAM-guided implantation. Successful lead placements in other locations guided by anatomical or physiologically defined positions are demonstrated in individual cases. However, map shifts are frequently encountered and should be recognized and corrected. Conclusion: EAM-guided His bundle lead implantation seems to be a useful tool for arriving at high success rates for new His lead implanters with a steep learning curve, if appropriate precautions are undertaken. In selected cases EAM and CT scan image integration can be of benefit in lead implantation in other locations. Knowledge of specific problems in using EAM for device procedures should be recognized.

Competing Interests: Funding Support and Author Disclosures The authors have reported that they have no relationships relevant to the contents of this paper to disclose.

Integration of electroanatomical map (EAM) with preacquired three-dimensional (3D) cardiac images provides detailed appreciation of the complex anatomy of the left atrium (LA) and pulmonary vein (PV). High-density (HD) multi-electrode mapping catheters have enabled creating more accurate EAM reflecting real-time volume-rendered LA–PV geometry during atrial fibrillation (AF) ablation. However, no study has compared the outcomes of AF ablation using HD–EAM versus 3D-merged map. We aimed to investigate the procedural and clinical outcomes of AF ablation with HD–EAM (HD–EAM group) versus 3D-merged map (Merge group). One hundred patients (59.5 ± 11.5 years, 53% with paroxysmal AF [PAF]) were randomly assigned (1:1) to HD–EAM or Merged group. HD multi-electrode mapping and contact force (CF)-sensing catheters were used to create virtual LA–PV chamber and to perform wide antral circumferential ablation (WACA), respectively. The two groups showed no significant differences in baseline characteristics and procedural data including ablation time, fluoroscopy time, LA voltage, and CF. PV isolation with a single WACA line was achieved in 21 (42%) and 27 (54%) patients in the Merge and HD-EAM groups, respectively (P = NS). CF was significantly lower in lesions with gap than lesions without gap after a single WACA (7.3 ± 7.3 g vs. 16.0 ± 8.3, respectively, P < 0.001). During the 12-month follow-up, no significant difference in AF recurrence was observed between two groups, irrespective of AF type. In multivariate analysis, non-PAF was an independent risk factor for AF recurrence. Integration of 3D cardiac imaging did not improve procedural and clinical outcomes. HD–EAM provides an accurate real-time LA geometry. [ABSTRACT FROM AUTHOR]

Background: The purpose of this meta‐analysis was to evaluate the impact of image integration technique on clinical and procedural outcomes in patients undergoing radiofrequency catheter ablation of atrial fibrillation with a three‐dimensional electroanatomic mapping system. Methods: Randomized controlled trials were identified through a systematic literature search of PubMed and CENTRAL databases from inception to April 2020. The primary outcome was arrhythmia recurrence during the follow‐up period. The secondary outcomes were the difference in total procedural time and fluoroscopy time. Results: Four studies with a total of 749 patients were included. The pooled result showed no statistically significant difference between the groups with respect to arrhythmia recurrence (RR, 0.75; 95% CI, 0.47‐1.21), fluoroscopy time (MD, −6 minutes; 95% CI, −23.4 to 11.3), and total procedural time (MD, 1.1 minutes; 95% CI, −31.8 to 34.1). Conclusion: Image integration to guide radiofrequency catheter ablation for patients with atrial fibrillation does not improve clinical and procedural outcomes. [ABSTRACT FROM AUTHOR]

Competing Interests: Conflict of interest: F.J.v.S. is a cofounder, chief technical officer, and shareholder of CART-Tech B.V. E.R. is an employee of CART-Tech B.V.

Minimum spanning tree (MST)-based clustering is one of the most important clustering techniques in the field of data mining. Although traditional MST-based clustering algorithm has been researched for decades, it still has some limitations for data sets with different density distribution. After analyzing the advantages and disadvantages of the traditional MST-based clustering algorithm, this paper presents two new methods to improve the traditional clustering algorithm. There are two steps of our first method: compute a scaled-MST with scaled distance to find the longest edges between different density clusters and clustering based on the MST. To improve the performance, our second scaled-MST-clustering works by merging the MST construction and inconsistent edges' detection into one step. To verify the effectiveness and practicability of the proposed method, we apply our algorithm on image segmentation and integration. The encouraging performance demonstrates the superiority of the proposed method on both small data sets and high dimensional data sets. [ABSTRACT FROM AUTHOR]

Aims: Three-dimensional rotational angiography (3DRA) of the left atrium (LA) and the esophagus is a simple and safe method for analyzing the relationship between the esophagus and the LA during catheter ablation of atrial fibrillation. The purpose of this study is to describe the location of the esophagus relative to the LA and mobility of the esophagus during ablation procedure. Methods: From 3/2011 to 9/2015, 3DRA of the LA and esophagus was performed in 326 patients before catheter ablation of atrial fibrillation. 3DRAwas performed with visualization of the esophagus via peroral administration of a contrast agent. The positions of the esophagus were determined at the beginning of the procedure, for part of patients also at the end of procedure with contrast esophagography. Results: The most frequent position is behind the center of the LA (91 pts., 31.9%) The least frequent position is behind the right pulmonary veins (27 pts., 9.4%). The average shift of the esophagus position was 3.36 ± 2.15 mm, 3.59 ± 2.37 mm and 3.67 ± 3.23 mm for superior, middle and inferior segment resp. Conclusions: The position of the esophagus to the LA is highly variable. The most common position of the esophagus relative to the LA is behind the middle and left part of the posterior wall of the LA. The least frequently observed position is behind the right pulmonary veins. No significant position change of esophagus motion from before to after the ablation procedure in the majority (≥95%) of the patients was observed.

Background: We present a new, easily applicable approach for the guidance of cryoballoon (CB) pulmonary vein isolation (PVI) procedures that use the combination of a 3D‐mapping system image integration module and computed tomographic (CT)–derived anatomy. The aim of this retrospective, nonrandomized study was to investigate: (a) an alternative use for an established radiofrequency image integration module for cryo procedures; (b) a guidance technology for cryo PVI based on integrated CT anatomy; and (c) its clinical impact. Methods and results: CT left atrium–angiography was performed in 50 consecutive patients before a CB PVI procedure, and a 3D reconstruction of the cardiac anatomy was segmented. A total of 25 patients were treated using conventional fluoroscopy; 25 patients were treated using the 3D image integration technique. In the image integration group, the CARTO3 UNIVU (Biosense Webster) module was used for image integration of 3D anatomy and fluoroscopic imaging. Transseptal puncture and cryo PVI were guided by 3D‐overlay imaging. Procedures were feasible without complications in all patients and cryo PVI procedures were successfully guided using the image integration technique. The intraprocedural time needed to perform image integration was 37 ± 10 seconds. Fluoroscopy time was 31.7 ± 11.7 minutes in the conventional group and 20.1 ± 7.9 minutes in the image integration group (P < .001), procedure time was 116.3 ± 29.0 minutes in the conventional group vs 101.2 ± 20.9 minutes in the 3D group (P = .04). Conclusion: 3D‐overlay guidance of CB PVI is feasible, safe, and applicable in real time with minimal effort. It may significantly reduce radiation exposure by introducing 3D information, known from electroanatomic mapping systems, into cryo PVI procedures. [ABSTRACT FROM AUTHOR]

Before delivering of intensity-modulated radiotherapy, kilo-voltage image-guidance radiotherapy is widely used in setup error correction and monitoring intra-fraction motion effectively. Accordingly, this study proposes and tests an image integration technique for observing intra-fraction motion during beam delivery, with the wider objective of reducing both image-guidance time and the dose delivered to normal breast tissue. The study sample comprised 33 female patients with breast cancer, and 241 sets of portal images acquired using a VARIAN aSi-1000 electronic portal imaging device. Motion amplitudes and vectors were collected and calculated separately by two senior therapists. The setup error in 3 axes was computed for every fraction, with average shifting for lateral, longitudinal and vertical direction was −0.3-mm ± 0.5, −0.1-mm ± 0.5 and −0.6-mm ± 1.6, with the average vector of setup error being 2.9-mm ± 1.4. The average intra-fraction motion for vertical direction was (A: −0.1-mm ± 1.0; B: −0.0 ± 1.1), for longitudinal was (A: −0.4-mm ± 1.7; B: 2.0 ± 1.1), and for lateral direction was (A: 0.3-mm ± 1.3; B: 0.2 ± 1.8). The average intra-fraction vector was 2.9-mm ± 1.3 for therapist A, and 3.4-mm ± 1.8 for therapist B. Offline Review commercial software was utilized for setup error and motion analysis, and data analysis and reliability testing were conducted with statistical package of the social sciences. Pearson correlations between the two therapists was moderate (0.59, p << 0.01), and the Cohen's kappa value for inter rater agreement between different evaluators was fair in the anterior-posterior direction (0.25, p << 0.01), with slight agreement in other two directions and vectors. The study presented efficient and dose reduction method to evaluate setup error and intra-fraction motion during breast intensity-modulated radiotherapy treatment. [ABSTRACT FROM AUTHOR]

We propose a reference-based filtering method that transforms the local color distribution of individual image patches. With our method, the color of a reference image is transformed by patch-wise color transformation so that it comes close to a noisy input image. Our method can be regarded as an extended version of reference-based filtering methods, such as guided image filtering and our previously proposed linear local color distribution transformation (LCDT). The main contribution is to enable more flexible transformation, which is required in some applications, e.g. , flash/no-flash image integration and high dynamic range (HDR) image generation. We also propose an efficient framework for HDR image generation which is particularly suitable for generation of dark scenes without loss of image contrast. Experimental results show that the proposed quadratic LCDT achieves more robust color transformation, even in flash/no-flash image integration, and it was confirmed that the proposed framework based on quadratic LCDT is effective in HDR image generation. [ABSTRACT FROM AUTHOR]

Aims: An appropriate left ventricular (LV) lead position is a pre-requisite for response to cardiac resynchronization therapy (CRT) and is highly patient-specific. The purpose of this study was to develop a non-invasive pre-procedural CRT-roadmap to guide LV lead placement to a coronary vein in late-activated myocardium remote from scar.Methods and Results: Sixteen CRT candidates were prospectively included. Electrocardiographic imaging (ECGI), computed tomography angiography (CTA), and delayed enhancement cardiac magnetic resonance imaging (DE-CMR) were integrated into a 3D cardiac model (CRT-roadmap) using anatomic landmarks from CTA and DE-CMR. Electrocardiographic imaging was performed using 184 electrodes and a CT-based heart-torso geometry. Coronary venous anatomy was visualized using a designated CTA protocol. Focal scar was assessed from DE-CMR. Cardiac resynchronization therapy-roadmaps were constructed for all 16 patients [left bundle branch block: n = 6; intraventricular conduction disturbance: n = 8; narrow-QRS (ablate and pace strategy); n = 1; right bundle branch block: n = 1]. The number of coronary veins ranged between 3 and 4 per patient. The CRT-roadmaps showed no (n = 5), 1 (n = 6), or 2 (n = 5) veins per patient located outside scar in late-activated myocardium [≥50% QRS duration (QRSd)]. Final LV lead position was outside scar in late-activated myocardium in 11 out of 14 implanted patients, while a LV lead in scar was unavoidable in the remaining three patients.Conclusion: A non-invasive pre-implantation CRT-roadmap was feasible to develop in a case series by integration of coronary venous anatomy, myocardial-scar localization, and epicardial electrical activation patterns, anticipating on clinically relevant features. [ABSTRACT FROM AUTHOR]

Competing Interests: Funding Support and Author Disclosures The authors have reported that they have no relationships relevant to the contents of this paper to disclose.

An estimate of synchrotron hard X‐ray incident beam polarization is obtained by partial two‐dimensional image masking followed by integration. With the correct polarization applied to each pixel in the image, the resulting one‐dimensional pattern shows no discontinuities arising from the application of the mask. Minimization of the difference between the sums of the masked and unmasked powder patterns allows estimation of the polarization to ±0.001. [ABSTRACT FROM AUTHOR]

This paper investigates the positioning accuracy of image pairs achieved by integrating images from multiple satellites. High-resolution satellite images from IKONOS, QuickBird, and KOMPSAT-2 for Daejeon, Korea were combined to produce pairs of stereo images. From single-satellite stereo pairs to multiple-satellite image pairs, all available combinations were analyzed via a rational function model (RFM). The positioning accuracy of multiple-satellite pairs was compared to a typical single-satellite stereo pair. The results show that dual-satellite integration can be an effective alternative to single-satellite stereo imagery for horizontal position mapping, but is less accurate for vertical mapping. The integration of additional higher-resolution images can improve the overall accuracy of the existing two images, but, conversely, may result in lower accuracy when very weak convergence or bisector elevation (BIE) angles occur. This highlights that the use of higher resolution images may not ensure improved accuracy, as it can result in very weak geometry. The findings confirm that multiple-satellite images can replace or enhance typical stereo pairs, but also suggest the need for careful verification, including consideration of various geometric elements and image resolution. This paper reveals the potential, limitations, and important considerations for mapping applications using images from multiple satellites.

Successful mapping and ablation of ventricular tachycardias remains a challenging clinical task. Whereas conventional entrainment and activation mapping was for many years the gold standard to identify reentrant circuits in ischaemic ventricular tachycardia ablation procedures, substrate mapping has become the cornerstone of ventricular tachycardia ablation. In the last decade, technology has dramatically improved. In parallel to high-density automated mapping, cardiac imaging and image integration tools are increasingly used to assess the structural ventricular tachycardia substrate. The aim of this review is to describe the technologies underlying these new mapping systems and to discuss their possible role in providing new insights into identification and visualization of reentrant tachycardia mechanisms. [ABSTRACT FROM AUTHOR]

Purpose: Intracardiac echocardiographic (ICE) imaging might be useful for integrating three-dimensional computed tomographic (CT) images for left atrial (LA) catheter navigation during atrial fibrillation (AF) ablation. However, the optimal CT image integration method using ICE has not been established.Methods: This study included 52 AF patients who underwent successful circumferential pulmonary vein isolation (CPVI). In all patients, CT image integration was performed after the CPVI with the following two methods: (1) using ICE images of the LA derived from the right atrium and right ventricular outflow tract (RA-merge) and (2) using ICE images of the LA directly derived from the LA added to the image for the RA-merge (LA-merge). The accuracy of these two methods was assessed by the distances between the integrated CT image and ICE image (ICE-to-CT distance), and between the CT image and actual ablated sites for the CPVI (CT-to-ABL distance).Results: The mean ICE-to-CT distance was comparable between the two methods (RA-merge = 1.6 ± 0.5 mm, LA-merge = 1.7 ± 0.4 mm; p = 0.33). However, the mean CT-to-ABL distance was shorter for the LA-merge (2.1 ± 0.6 mm) than RA-merge (2.5 ± 0.8 mm; p < 0.01). The LA, especially the left-sided PVs and LA roof, was more sharply delineated by direct LA imaging, and whereas the greatest CT-to-ABL distance was observed at the roof portion of the left superior PV (3.7 ± 2.8 mm) after the RA-merge, it improved to 2.6 ± 1.9 mm after the LA-merge (p < 0.01).Conclusions: Additional ICE images of the LA directly acquired from the LA might lead to a greater accuracy of the CT image integration for the CVPI. [ABSTRACT FROM AUTHOR]

Catheter ablation has an important role in the management of patients with ventricular tachycardia (VT) but is limited by modest long-term success rates. Magnetic resonance imaging (MRI) can provide valuable anatomic and functional information as well as potentially improve identification of target sites for ablation. A major limitation of current MRI protocols is the spatial resolution required to identify the areas of tissue responsible for VT but recent developments have led to new strategies which may improve substrate assessment. Potential ways in which detailed information gained from MRI may be utilized during electrophysiology procedures include image integration or performing a procedure under real-time MRI guidance. Image integration allows pre-procedural magnetic resonance (MR) images to be registered with electroanatomical maps to help guide VT ablation and has shown promise in preliminary studies. However, multiple errors can arise during this process due to the registration technique used, changes in ventricular geometry between the time of MRI and the ablation procedure, respiratory and cardiac motion. As isthmus sites may only be a few millimetres wide, reducing these errors may be critical to improve outcomes in VT ablation. Real-time MR-guided intervention has emerged as an alternative solution to address the limitations of pre-acquired imaging to guide ablation. There is now a growing body of literature describing the feasibility, techniques, and potential applications of real-time MR-guided electrophysiology. We review whether real-time MR-guided intervention could be applied in the setting of VT ablation and the potential challenges that need to be overcome. [ABSTRACT FROM AUTHOR]

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Aims: During ablation in the vicinity of the coronary arteries establishing a safe distance from the catheter tip to the relevant vessels is mandatory and usually assessed by fluoroscopy alone. The aim of the study was to investigate the feasibility of an image integration module (IIM) for continuous monitoring of the distance of the ablation catheter tip to the main coronary arteries during ablation of ventricular arrhythmias (VA) originating in the sinus of valsalva (SOV) and the left ventricular summit part of which can be reached via the great cardiac vein (GCV).Methods and results: Of 129 patients undergoing mapping for outflow tract arrhythmias from June 2014 till October 2015, a total of 39 patients (52.4 ± 18.1 years, 17 female) had a source of origin in the SOV or the left ventricular summit. Radiofrequency (RF) ablation was performed when a distance of at least 5 mm could be demonstrated with IIM. A safe distance in at least one angiographic plane could be demonstrated in all patients with a source of origin in the SOV, whereas this was not possible in 50% of patients with earliest activation in the summit area. However, using the IIM a safe position at an adjacent site within the GCV could be obtained in three of these cases and successful RF ablation performed safely without any complications. Ablation was successful in 100% of patients with an origin in the SOV, whereas VAs originating from the left ventricular summit could be abolished completely in only 60% of cases.Conclusion: Image integration combining electroanatomical mapping and fluoroscopy allows assessment of the safety of a potential ablation site by continuous real-time monitoring of the spatial relations of the catheter tip to the coronary vessels prior to RF application. It aids ablation in anatomically complex regions like the SOV or the ventricular summit providing biplane angiograms merged into the three-dimensional electroanatomical map. [ABSTRACT FROM AUTHOR]

Background. Three-dimensional rotational angiography (3DRA) of the heart is an imaging technique that displays the left atrium and adjacent structures during catheter ablation of atrial fibrillation. The aim is to evaluate the feasibility and safety of 3DRA for imaging the right and left ventricles of patients undergoing catheter ablation of ventricular arrhythmias. Methods. From 8/2010 to 6/2015, 35 patients underwent 3DRA of the right (20 patients) or left ventricle (15 patients) with a Philips Allura FD 10 X-ray system using a direct protocol. The success rate of the 3D model, as well as the procedure times and complications of 3DRA, was evaluated, and the 3DRA model was compared with ventricular computer tomography (CT). Results. The overall 3D model success rate was 91.4%. The 3D models were graded as excellent for 65.7% of patients and as useful for 25.7% of patients. The imaging success rate was slightly higher for the right ventricle than for the left ventricle (95%, 86.7%, respectively). The times required to perform 3DRA of the right and left ventricle were 12.5 +/- 2.1 min and 14.7 +/- 2.8 min, respectively. There were no significant differences between 3DRA and ventricular CT. Conclusion. Ventricular 3DRA allows the easy and safe creation of 3D models of the cardiac ventricles. The success rate is comparable to the success rate of the 3DRA for imaging the left atrium. There was no difference in imaging quality between the two ventricles. 3DRA models of the ventricles are comparable with CT models of the ventricles. [ABSTRACT FROM AUTHOR]

Aims: The objective of this study was to evaluate the mobility of the oesophagus and the stability of the three-dimensional (3D) model of the oesophagus using 3D rotational angiography (3DRA) of the left atrium (LA) and the oesophagus, fused with live fluoroscopy during catheter ablation for atrial fibrillation.Methods and Results: From March 2015 to September 2015, 3DRA of the LA and the oesophagus was performed in 33 patients before catheter ablation for atrial fibrillation. Control contrast oesophagography was performed every 30 min. The positions of the oesophagograms and the 3D model of the LA and the oesophagus were repeatedly measured and compared with the spine. The average shift of the oesophagus ranged from 2.7 ± 2.2 to 5.0 ± 3.5 mm. The average real-time oesophageal shift ranged from 2.7 ± 2.2 to 3.8 ± 3.4 mm. No significant shift was detected until the 90th minute of the procedure. The average shift of the 3D model of the LA and the oesophagus ranged from 1.4 ± 1.8 to 3.3 ± 3.0 mm (right-left direction) and from 0.9 ± 1.2 to 2.2 ± 1.3 mm (craniocaudal direction). During the 2 h procedure, there were no significant shifts of the model.Conclusion: During catheter ablation for atrial fibrillation, there is no significant change in the position of the oesophagus until the 90th minute of the procedure and no significant shift in the 3D model of the LA and the oesophagus. The 3D model of the oesophagus reliably depicts the position of the oesophagus during the entire procedure. [ABSTRACT FROM AUTHOR]

Background: Electroanatomical voltage mapping (EAVM) has been compared with late gadolinium enhancement cardiovascular magnetic resonance (LGE-CMR), which cannot delineate diffuse fibrosis. T1-mapping CMR overcomes the limitations of LGE-CMR, but it has not been directly compared against EAVM., Objectives: This study aims to assess the relationship between left ventricular (LV) endocardial voltage obtained by EAVM and extracellular volume (ECV) obtained by T1 mapping., Methods: The study investigated patients who underwent endocardial EAVM for ventricular arrhythmias (CARTO 3, Biosense Webster) together with preprocedural contrast-enhanced T1 mapping (Ingenia 3T, Philips Healthcare). After image integration, EAVM datapoints were projected onto LGE-CMR and ECV-encoded images. Average values of unipolar voltage (UV), bipolar voltage (BV), LGE transmurality, and ECV were merged from corresponding cardiac segments (6 per slice) and pooled for analysis., Results: The analysis included data from 628 segments from 18 patients (57 ± 13 years of age, 17% females, LV ejection fraction 48% ± 14%, nonischemic/ischemic cardiomyopathy/controls: 8/6/4 patients). Based on the 95th and 5th percentile values obtained from the controls, ECV >33%, BV <2.9 mV, and UV <6.7 mV were considered abnormal. There was a significant inverse association between voltage and ECV, but only in segments with abnormal ECV. Increased ECV could predict abnormal BV and UV with acceptable accuracy (area under the curve of 0.78 [95% CI: 0.74-0.83] and 0.84 [95% CI: 0.79-0.88])., Conclusions: This study found a significant inverse relationship between LV endocardial voltage and ECV. Real-time integration of T1 mapping may guide catheter mapping and may allow identification of areas of diffuse fibrosis potentially related to ventricular arrhythmias., Competing Interests: Funding Support and Author Disclosures This work was partially supported by an ESC Research Grant received by Dr Sramko. The authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2023. Published by Elsevier Inc.)

Background We aimed to optimize the acquisition of the left atrial (LA) and pulmonary vein (PV) ultrasound contours for more accurate integration of intracardiac echocardiography (ICE) and computed tomography (CT) using the CARTO ® 3 system during atrial fibrillation (AF) ablation. Methods Eighty-five AF patients underwent integration of ICE and CT using (1) the LA roof and posterior wall contours acquired from the right atrium (RA), (2) all LA/PV contours from the RA (Whole-RA-integration), (3) the LA roof/posterior wall contours from the RA and right ventricular outflow tract (RVOT) (Posterior-RA/RV-integration), and (4) all LA/PV contours from the RA and RVOT (Whole-RA/RV-integration). The integration accuracy was compared using the (1) surface registration error, (2) distances between the three-dimensional CT and eight specific sites on the anterior, posterior, superior, and inferior aspects of the right and left circumferential PV isolation lines, and (3) registration score: a score of 0 or 1 was assigned for whether or not each specific site was visually aligned with the CT, and summed for each method (0 best, 8 worst). Results Posterior-RA/RV-integration revealed a significantly lower surface registration error (1.30 ± 0.15 mm) than Whole-RA- and Whole-RA/RV-integration (p < 0.001). The mean distances of the eight specific sites and the registration score for Posterior-RA/RV-integration (median 1.26 mm and 2, respectively) were significantly smaller than those for the other integration approaches (p < 0.001). Conclusions Image integration with the LA roof and posterior wall contours acquired from the RA and RVOT may provide greater accuracy for catheter navigation with three-dimensional CT during AF ablation. [ABSTRACT FROM AUTHOR]