Biplane Imaging Research Articles

High-fidelity pose estimation for real-time extended reality (XR) visualization for cardiac catheterization

Extended reality (XR) technologies are emerging as promising platforms for medical training and procedural guidance, particularly in complex cardiac interventions. This paper presents a high-fidelity methodology to perform real-time 3D catheter tracking and visualization during simulated cardiac interventions. A custom 3D-printed setup with mounted cameras enables biplane video capture of a catheter. A computer vision algorithm processes the biplane images in real-time to reconstruct the 3D catheter trajectory represented by any designated number of points along its length. This method accurately localizes the catheter tip within 1 mm and can reconstruct any arbitrary catheter configuration. The tracked catheter data is integrated into an interactive Unity-based scene rendered on the Meta Quest 3 headset. The visualization seamlessly combines a reconstructed 3D patient-specific heart model with the dynamically tracked catheter, creating an immersive extended reality training environment. Our experimental study, involving six participants, demonstrated that the 3D visualization provided by the proposed XR system significantly outperformed 2D visualization in terms of speed and user experience. This suggests that the XR system has the potential to enhance catheterization training by improving spatial comprehension and procedural skills. The proposed system demonstrates the potential of XR technologies to transform percutaneous cardiac interventions through improved visualization and interactivity.

Single-Plane Versus Synchronous Biplane Ultrasound Imaging During Vascular Access Procedures: Which Is Better and How Can We Improve?

Highlights Biplane ultrasound imaging reduces need for probe manipulation during procedure. Providers note clinical benefit of biplane ultrasound imaging for vascular access. Biplane disadvantages include probe size, imaging quality, size of the screen. Thorough didactic and practical education is essential for biplane success. Abstract Background: Use of ultrasound guidance for vascular access procedures is commonplace in inpatient and outpatient care settings. Standard ultrasound probes offer the operator a single-plane view, necessitating rotation of probe to attain dual complimentary views. This mechanical probe rotation increases technical difficulty of ultrasound use. The purpose of this study is to evaluate the rate of cannulation success and efficiency of a synchronous biplane ultrasound mode in ultrasound-guided arterial line placement as compared with a standard single-view ultrasound mode in the operating room setting. Methods: Patients scheduled for elective surgery in which a radial arterial catheter would be used for hemodynamic monitoring were approached for consent to this study. Patients were randomized to either undergo placement with single-plane view versus synchronous biplane view; outcomes were recorded. Providers were provided preprocedural ultrasound education as well as the option of a short hands-on experience; their level of experience was noted. Results: Placement time of a peripheral arterial catheter was longer and required more attempts to be successful using synchronous biplane imaging as compared with single-plane imaging across providers of all skill/experience levels. Subjectively, providers noted the benefit of synchronous biplane imaging in vascular access; however, disadvantages including probe size, quality of imaging, and size of the screen were noted. Discussion: Thorough education regarding the use and functionality of biplane synchronous imaging in vascular access is essential. Additional guided-practice time with experienced operators could also be helpful to overcome the challenges observed in this study.

Computer Aided Intracranial Aneurysm Treatment Based on 2D/3D Mapping, Virtual Deployment and Online Distal Marker Detection.

To introduce a computational tool for peri-interventional intracranial aneurysm treatment guidance that maps preoperative planning information from simulation onto real-time X-Ray imaging. Preoperatively, multiple flow diverter (FD) devices are simulated based on the 3D mesh of the vessel to treat, to choose the optimal size and location. In the peri-operative stage, this 3D information is aligned and mapped to the continuous 2D-X-Ray scan feed from the operating room. The current flow diverter position in the 3D model is estimated by automatically detecting the distal FD marker locations and mapping them to the treated vessel. This allows to visually assess the possible outcome of releasing the device at the current position, and compare it with the one chosen pre-operatively. The full pipeline was validated using retrospectively collected biplane images from four different patients (5 3D-DSA datasets in total). The distal FD marker detector obtained an average F1-score of 0.67 ( ) in 412 2D-X-Ray scans. After aligning 3D-DSA + 2D-X-Ray datasets, the average difference between simulated and deployed positions was 0.832 mm ( mm). Finally, we qualitatively show that the proposed approach is able to display the current location of the FD compared to their pre-operatively planned position. The proposed method allows to support the FD deployment procedure by merging and presenting preoperative simulation information to the interventionists, aiding them to make more accurate and less risky decisions.

Prediction of presence and severity of metabolic syndrome using regional body volumes measured by a multisensor white-light 3D scanner and validation using a mobile technology

Abstract Aims To test whether an index based on the combination of demographics and body volumes obtained with a multisensor 3D body volume (3D-BV) scanner and biplane imaging using a mobile application (myBVI®) will reliably predict the severity and presence of metabolic syndrome (MS). Methods and results We enrolled 1280 consecutive subjects who completed study protocol measurements, including 3D-BV and myBVI®. Body volumes and demographics were screened using the least absolute shrinkage and selection operator to select features associated with an MS severity score and prevalence. We randomly selected 80% of the subjects to train the models, and performance was assessed in 20% of the remaining observations and externally validated on 133 volunteers who prospectively underwent myBVI® measurements. The mean ± SD age was 43.7 ± 12.2 years, 63.7% were women, body mass index (BMI) was 28.2 ± 6.2 kg/m2, and 30.2% had MS and an MS severity z-score of −0.2 ± 0.9. Features β coefficients equal to zero were removed from the model, and 14 were included in the final model and used to calculate the body volume index (BVI), demonstrating an area under the receiving operating curve (AUC) of 0.83 in the validation set. The myBVI® cohort had a mean age of 33 ± 10.3 years, 61% of whom were women, 10.5% MS, an average MS severity z-score of −0.8, and an AUC of 0.88. Conclusion The described BVI model was associated with an increased severity and prevalence of MS compared with BMI and waist-to-hip ratio. Validation of the BVI had excellent performance when using myBVI®. This model could serve as a powerful screening tool for identifying MS.

Fourier feature network for 3D vessel reconstruction from biplane angiograms

3D reconstruction of biplane cerebral angiograms remains a challenging, unsolved research problem due to the loss of depth information and the unknown pixelwise correlation between input images. The occlusions arising from only two views complicate the reconstruction of fine vessel details and the simultaneous addressing of inherent missing information. In this paper, we take an incremental step toward solving this problem by reconstructing the corresponding 2D slice of the cerebral angiogram using biplane 1D image data. We developed a coordinate-based neural network that encodes the 1D image data along with a deterministic Fourier feature mapping from a given input point, resulting in a slice reconstruction that is more spatially accurate. Using only one 1D row of biplane image data, our Fourier feature network reconstructed the corresponding volume slices with a peak signal-to-noise ratio (PSNR) of 26.32 ± 0.36, a structural similarity index measure (SSIM) of 61.38 ± 1.79, a mean squared error (MSE) of 0.0023 ± 0.0002, and a mean absolute error (MAE) of 0.0364 ± 0.0029. Our research has implications for future work aimed at improving backprojection-based reconstruction by first examining individual slices from 1D information as a prerequisite.

Enlarge the dynamic range of Shack-Hartmann wavefront sensor based on biplanar image acquisition and segmentation method

In present paper, a simple and robust method to expand the SHWS dynamic range is proposed. The intensity patterns are obtained with biplanar image acquisition and segmentation. The process involves calculating the spot centroids of two images and then matching the centroid of the spots of light with the center of a micro-lens array. This also resolves the issue of mandating the determination of centroids exclusively within the corresponding detection area. It is performed a comparative analysis between our proposed method and the conventional method for measuring large wavefronts, utilizing both numerical simulations and experiments. Additionally, a statistical analysis of the dynamic range of the method for wavefront measurement was conducted. This study demonstrates that the biplanar image acquisition and segmentation method provided a larger dynamic range while ensuring accuracy relative to the single image acquisition of conventional algorithm

Aberrant right subclavian artery – A roadblock for radial interventionalists

ABSTRACT Extreme difficulty was faced while negotiating diagnostic catheter in a septuagenarian hypertensive male undergoing transradial coronary angiography due to the long tortuous course of the aortic arch. Biplane imaging helped in unearthing an aberrant right subclavian artery originating anomalously from the descending thoracic aorta.

The Importance of Weight-Based Protocols and Reduction of Frame Rates in ASD Percutaneous Closure

Introduction: In the context of interventional and diagnostic cardiology procedures, there is a growing effort to minimize exposure to ionizing radiation. Most modern angiography machines allow selection of exposure parameters based on the patient's weight. Our experience has led us to question whether the use of weight-based protocols is the right approach for pediatric interventional cardiology exams. Aim and Materials: The purpose of this research is to investigate the efficacy of techniques aimed at reducing radiation exposure during ASD percutaneous closure in pediatric patients. Since 2020, in all patients we used predefined acquisition parameters with a low exposure level (CARD <6Kg) and reduced pulsations to 4p/s. Therefore, from 2020 we used the lowest possible radiological pediatric protocol regardless of patient weight. We compared this group of patients (B) with an historical group of patients (A) with an ASD, in which a radiological protocol based only on patient’s weight was applied. Results: Group A included 92 patients with ostium secundum atrial septal defect. Group B included 114 patients with ostium secundum atrial septal defect. In this group, 22 patients received a Gore Cardioform ASD occluder device with the need of a biplane imaging. The two groups were comparable in terms of age (p=0.1) and weight (p=0.2). The absorbed dose in group A was significantly higher than in group B. Median total air kerma was 6.55 mGy(1.2-255,6 mGy) in group A and 5.25 mGy(0.4-140.5 mGy) in group B (p 0.001). Dose area product (DAP) was 130,2 μGym²(24.25-5774 μGym²) in group A and 67.1 μGym²(8.6-3107 μGym²) in group B(p 0.001). Conclusion: Our strategy resulted in a significant reduction in radiation exposure to the patients while maintaining good radioscopic resolution. This significance was maintained despite the use of new devices in 2021 in addition to Amplatzer (GORE-Occlutech).

Bayesian posterior density estimation reveals degeneracy in three-dimensional multiple emitter localization

Single-molecule localization microscopy requires sparse activation of emitters to circumvent the diffraction limit. In densely labeled or thick samples, overlap of emitter images is inevitable. Single-molecule localization of these samples results in a biased parameter estimate with a wrong model of the number of emitters. On the other hand, multiple emitter fitting suffers from point spread function degeneracy, which increases model and parameter uncertainty. To better estimate the model, parameters and uncertainties, a three-dimensional Bayesian multiple emitter fitting algorithm was constructed using Reversible Jump Markov Chain Monte Carlo. It reconstructs the posterior density of both the model and the parameters, namely the three-dimensional position and photon intensity, of overlapping emitters. The ability of the algorithm to separate two emitters at varying distance was evaluated using an astigmatic point spread function. We found that for astigmatic imaging, the posterior distribution of the emitter positions is multimodal when emitters are within two times the in-focus standard deviation of the point spread function. This multimodality describes the ambiguity in position that astigmatism introduces in localization microscopy. Biplane imaging was also tested, proving capable of separating emitters up to 0.75 times the in-focus standard deviation of the point spread function while staying free of multimodality. The posteriors seen in astigmatic and biplane imaging demonstrate how the algorithm can identify point spread function degeneracy and evaluate imaging techniques for three-dimensional multiple-emitter fitting performance.

Accurate Prediction of Retrograde Collateral Channel Crossing in Coronary Artery Chronic Total Occlusion Intervention

Successful collateral channel (CC) crossing is an essential step in retrograde chronic total occlusion (CTO) percutaneous coronary interventions (PCI). We previously developed a dedicated CC score based on CC size and tortuosity to facilitate target CC selection. Validation and comparison to other scoring systems were lacking. Thus, the aims of this study were to 1) validate the CC score in a larger independent cohort, and 2) compare its accuracy and clinical usefulness with the J-channel score. All coronary CTO PCIs attempted by experienced high-volume operators from January, 2017 to December, 2021 were enrolled. The CC and J-channel scores were calculated for all attempted CCs with bi-plane high-resolution cine angiography images. CC crossing success was defined as guidewire reaching the distal true lumen retrogradely. In total, 502 patients who received CTO PCI were included. The retrograde approach was utilized in 244 target CTOs, and a total of 329 CCs were attempted. The overall CC crossing rate was 67.8% (223/329) and final technical success rate 92.2% (225/244). The average CC score was 2.0 and average J-channel score was 0.71. The sensitivity and specificity of successful CC crossing with the CC score ≥2 were 81.2%, and 84.0%, respectively. Comparison between the CC score (area under the curve [AUC] 0.87; 95% confidence interval [CI] 0.83-0.90) and the J-channel score (AUC 0.61; 95% CI 0.55-0.67) demonstrated superior predictive performance of the CC score (p <0.001). The CC score was an easy-to-use and accurate tool for the prediction of successful CC crossing in retrograde CTO PCI. The CC score can help operators select the ideal target CC, thereby facilitating final procedural success.

Ultrasound-Enhancing Agent Safely Enhances Left Ventricular Visualization by Transthoracic Echocardiography in Patients on ECMO Support

The authors investigated if the use of ultrasound-enhancing agents (UEA) can safely improve left ventricular (LV) image quality by transthoracic echocardiography (TTE) in patients on extracorporeal membrane oxygenation (ECMO). This study was performed in a tertiary cardiothoracic and ECMO center in London, United Kingdom. The authors included 18 prospectively identified consecutive patients requiring TEE supported on peripherally implanted ECMO. TTE was performed before and after the UEA administration. The authors assessed the LV image quality using the biplane (apical-4-chamber and apical-2-chamber views) endocardial border definition index (1=good, 2=suboptimal, 3=poor, and 4=unavailable), as well as the feasibility of LV ejection fraction (LVEF) measurement. The authors also gathered sequential clinical information for the next 24 hours. The patients' median age was 47 years (35, 65), and 5 (28%) were women. The biplane endocardial border definition index improved from the suboptimal to the good range (2.167 [1.812, 3.042] v 1.500 [1.417, 1.792], p=0.0004) after the use of UEA. The feasibility of LVEF tripled from 25% (n=5) to 83% (n=15) (p=0.0008) with UEA use. The UEA did not set off the bubble alarm and did not impact clinical or ECMO parameters. The use of UEA significantly improved the quality of LV biplane images by transthoracic echocardiography, transforming them from suboptimal to good in patients supported with peripherally implanted ECMO. UEA use tripled the feasibility of measuring LVEF by TTE without affecting clinical and ECMO parameters.

DRR acceleration using inexpensive GPUs for model-image registration based joint kinematic measurements

Model-image registration methods are commonly used in research to measure three-dimensional joint kinematics from single-plane and bi-plane x-ray images. These methods have the potential to be beneficial if used clinically, but current techniques are too slow or expensive to be clinically practical. One technical element of these methods for measuring natural bone motion is the use of digitally reconstructed radiographs (DRRs). DRRs can be very expensive to compute, or require expensive and fast computer hardware. In this technical development, a numerically efficient Siddon-Jacobs algorithm for computing DRRs was implemented on a consumer-grade graphics card using a programming language for parallel architectures. Compared to traditional voxel projection algorithms with a central-processing-unit-only implementation, the parallel computation implementation on the graphics card provided speedups of 650–1546 times faster rendering, while retaining equivalent performance for joint kinematics measurements. The use of consumer grade graphics hardware may contribute to making model-image registration measurements of joint kinematics practical for clinical use.

Mono- and bi-plane sonographic approach for difficult accesses in the emergency department – A randomized trial

BackgroundThe insertion of peripheral intravenous (PIV) catheters is one of the most performed invasive procedures in acute healthcare settings. However, peripheral difficult vascular access (PDVA) is not uncommon and can lead to delays in administering essential medications. Ultrasound (US) has emerged as a valuable tool for facilitating PIV cannulation. Advancements in technology have introduced a technique known as bi-plane imaging, allowing the simultaneous display of both longitudinal and transverse views of vessels. We aimed to investigate whether the utilization of bi-plane imaging, as opposed to the single-plane approach, would yield superior results for PDVA in the emergency department (ED). MethodsThis study was a single-center randomized controlled trial. We included adult patients admitted to the ED who required PIV cannulation. Patients were randomly assigned to undergo cannulation using either the mono-plane or bi-plane approach, both performed by skilled providers. The primary outcome of the study was to compare the first attempt success rates between the two techniques. ResultsA total of 442 patients were enrolled, with 221 undergoing cannulation attempts using the mono-plane approach. Successful placement of a functioning PIV catheter was achieved in a single attempt for 313 out of 442 patients (70.8%). There was no significant difference in the success rates between the two study groups: 68.3% in the mono-plane group and 73.3% in the bi-plane group (p = 0.395). The median time required for a successful attempt differed between the groups, with 45 s (range 18–600) in the mono-plane group and 35 s (range 20–600) in the bi-plane group (p = 0.03). ConclusionsOur study confirms that US is a highly effective tool for facilitating PIV cannulation in patients with PDVA presenting to the ED. However, our investigation into the use of bi-plane imaging did not reveal a significant improvement when compared to mono-plane imaging.

Single-plane versus real-time biplane approaches for ultrasound-guided central venous catheterization in critical care patients: a randomized controlled trial

BackgroundCritical care patients often require central venous cannulation (CVC). We hypothesized that real-time biplane ultrasound-guided CVC would improve first-puncture success rate and reduce mechanical complications. The purpose of this study was to compare the success rate and safety of single-plane and real-time biplane approaches for ultrasound-guided CVC.MethodsFrom October 2022 to March 2023, 256 participants with critical illness requiring CVC were randomized to either the single-plane (n = 128) or biplane (n = 128) ultrasound-guided cannulation groups. The success rate, number of punctures, procedure duration, incidence of catheterization-related complications, and confidence score of operators were documented.ResultsThe central vein was successfully cannulated in all 256 participants (163 [64%] man and 93 [36%] women; mean age 69 ± 19 [range 13–104 years]), including 182 and 74 who underwent internal jugular vein cannulation (IJVC) and femoral vein cannulation (FVC), respectively. The incidence of successful puncture on the first attempt was higher in the biplane group than that in the single-plane group (91.6% vs. 74.7%; relative risk (RR), 1.226; 95% confidence interval (CI), 1.069–1.405; P = 0.002 for the IJVC and 90.9% vs. 68.3%; RR, 1.331; 95% CI, 1.053–1.684; P = 0.019 for the FVC). The biplane group was also associated with a higher first-puncture single-pass catheterization success rate (87.4% vs. 69.0% and 90.9% vs. 68.3%), fewer undesired punctures (1[1–1(1–2)] vs. 1[1–2(1–4)] and 1[1–1(1–3)] vs. 1[1–2(1–4)]), shorter cannulation time (205 s [162–283 (66–1,526)] vs. 311 s [243–401 (136–1,223)] and 228 s [193–306 (66–1,669)] vs. 340 s [246–499 (130–944)]), and fewer immediate complications (10.5% vs. 28.7% and 9.1% vs. 34.1%) for both IJVC and FVC (all P < 0.05).ConclusionReal-time biplane imaging of ultrasound-guided CVCs offers advantages over the single-plane approach for critically ill patients.Trial registration: This prospective RCT was registered at Chinese Clinical Trial Registry (ChiCTR2200064843). Registered 19 October 2022.

Integration of statistical shape modeling and alternating interpolation-based model tracking technique for measuring knee kinematics in vivo using clinical interleaved bi-plane fluoroscopy.

A 2D fluoroscopy/3D model-based registration with statistical shape modeling (SSM)-reconstructed subject-specific bone models will help reduce radiation exposure for 3D kinematic measurements of the knee using clinical alternating bi-plane fluoroscopy systems. The current study aimed to develop such an approach and evaluate in vivo its accuracy and identify the effects of the accuracy of SSM models on the kinematic measurements. An alternating interpolation-based model tracking (AIMT) approach with SSM-reconstructed subject-specific bone models was used for measuring 3D knee kinematics from dynamic alternating bi-plane fluoroscopy images. A two-phase optimization scheme was used to reconstruct subject-specific knee models from a CT-based SSM database of 60 knees using one, two, or three pairs of fluoroscopy images. Using the CT-reconstructed model as a benchmark, the performance of the AIMT with SSM-reconstructed models in measuring bone and joint kinematics during dynamic activity was evaluated in terms of mean target registration errors (mmTRE) for registered bone poses and the mean absolute differences (MAD) for each motion component of the joint poses. The mmTRE of the femur and tibia for one image pair were significantly greater than those for two and three image pairs without significant differences between two and three image pairs. The MAD was 1.16 to 1.22° for rotations and 1.18 to 1.22 mm for translations using one image pair. The corresponding values for two and three image pairs were 0.75 to 0.89° and 0.75 to 0.79 mm; and 0.57 to 0.79° and 0.6 to 0.69 mm, respectively. The MAD values for one image pair were significantly greater than those for two and three image pairs without significant differences between two and three image pairs. An AIMT approach with SSM-reconstructed models was developed, enabling the registration of interleaved fluoroscopy images and SSM-reconstructed models from more than one asynchronous fluoroscopy image pair. This new approach had sub-millimeter and sub-degree measurement accuracy when using more than one image pair, comparable to the accuracy of CT-based methods. This approach will be helpful for future kinematic measurements of the knee with reduced radiation exposure using 3D fluoroscopy with clinically alternating bi-plane fluoroscopy systems.

Diagnostic Accuracy of Transesophageal Echocardiographic Commissural-Biplane Approach in Identifying Mitral Valve Anatomy

Transesophageal echocardiography (TEE) conventional multiplane approach (MPA) and the newly proposed commissural-biplane approach (CBA) are the recommended algorithms for identifying the affected mitral valve (MV) segments in the setting of mitral regurgitation. To date, there are no reports to address the diagnostic performance of CBA. In this study we aim to analyze the diagnostic accuracy of CBA and MPA in comparison with three-dimensional echocardiographic findings in patients with severe mitral regurgitation. We prospectively enrolled 102 patients with severe mitral regurgitation. All patients underwent systematic TEE assessment of MV before surgical intervention to define the affected MV segments/scallops. The standard MPA includes 4-chamber, 2-chamber, long-axis, and commissural views; CBA was performed by obtaining the bicommissural view and simultaneous biplane imaging of the medial, middle, and lateral MV aspects. The findings of both TEE approaches were compared with three-dimensional TEE data to assess the diagnostic accuracy of MPA and CBA. The mean patient age was (65±11) years, and 37 (36.3%) were female. We found that CBA had an overall diagnostic accuracy between 88% and 97% in identifying the abnormal MV scallops; in contrast, MPA accuracy ranged between 82% and 95%. The CBA and MPA were the least accurate in identifying the P3 scallop-88% and 82% respectively; however, both were the most accurate in assessing the A2 segment-95% and 97%, respectively. The sensitivity of identifying commissural abnormalities was 80% with CBA and 30% with MPA. Three-dimensional TEE was found to have a strong agreement with CBA (averaged kappa of 0.81, P<.0001) and a modest agreement with MPA (averaged kappa of 0.61, P<.0001) in identifying abnormal anterior or posterior segments. On the other hand, three-dimensional TEE had a weak agreement with CBA (kappa of 0.43, P<.0001) and no agreement with MPA (kappa of 0.14, P=.153) in the assessment of commissural involvements. The CBA is more accurate than the MPA in the assessment of MV commissural involvement. Given the accuracy differences of the 2 approaches for specific leaflet/scallops, a comprehensive evaluation using both approaches is recommended for all MV scallop assessments.

Multi-angled simultaneous biplane High-Speed Angiography (HSA) of patient-specific 3D-printed aneurysm phantoms using 1000 fps CdTe Photon-Counting Detectors (PCD's).

1000 fps HSA enables visualization of flow details, which may be important in accurately guiding interventional procedures; however, single-plane imaging may lack clear visualization of vessel geometry and flow detail. The previously presented high-speed orthogonal biplane imaging may overcome these limitations but may still result in foreshortening of vessel morphology. In certain morphologies, acquiring two non-orthogonal biplane projections at multiple angles can provide better flow detail rather than a standard orthogonal biplane acquisition. Flow studies of aneurysm models were performed, where simultaneous biplane acquisitions at various angles separating the two detector views allowed for better evaluation of morphology and flow. 3D-printed, patient-specific internal carotid artery aneurysm models were imaged with various non-orthogonal angles between the two high-speed photon-counting detectors (7.5 cm x 5 cm FOV) to provide frame-correlated simultaneous 1000-fps image sequences. Fluid dynamics were visualized in multi-angled planes of each model using automated injections of iodine contrast media. The resulting dual simultaneous frame-correlated 1000-fps acquisitions from multiple planes of each aneurysm model provided improved visualization of complex aneurysm geometries and flow streamlines. Multi-angled biplane acquisitions with frame correlation allows for further understanding of aneurysm morphology and flow details: additionally, the ability to recover fluid dynamics at depth enables accurate analysis of 3D flow streamlines, and it is expected that multiple-planar views will enable better volumetric flow visualization and quantification. Such better visualization has the potential to improve interventional procedures.

A Machine Learning-Based Roll Angle Prediction for Intracardiac Echocardiography Catheter during Bi-Plane Fluoroscopy

Catheterization is a procedure used to diagnose and treat various cardiovascular diseases. Intracardiac echocardiography (ICE) is an emerging imaging modality that has gained popularity in these procedures due to its ability to provide high-resolution images of the heart and its surrounding structures in a minimally invasive manner. However, given its limited field of view, its orientation within the heart is difficult to judge simply from observing the acquired images. Therefore, ICE catheter tracking, which requires six degrees of freedom, would be useful to better guide interventionalists during a procedure. This work demonstrates a machine learning-based approach that has been trained to predict the roll angle of an ICE catheter using landmark scalar values extracted from bi-plane fluoroscopy images. The model consists of two fully connected deep neural networks that were trained on a dataset of bi-plane fluoroscopy images acquired from a 3D printed heart phantom. The results showed high accuracy in roll angle prediction, suggesting the ability to achieve 6 degrees of freedom tracking using bi-plane fluoroscopy that can be integrated into future navigation systems embedded into the c-arm, integrated within an AR/MR headset, or in other commercial navigation systems.

Tibia Nailing Using Modular Stand: A Technical Note.

Interlocking nailing is a well-established procedure for managing unstable tibial shaft fractures. Closed reduction and internal fixation of the tibial shaft fractures require ease of intraoperative positioning, maneuvering, and biplane imaging. We describe the use of an innovative modular tibia-nailing stand, which greatly enhances the ergonomics of the tibia nailing procedure.

Motion-corrected echo decorrelation imaging for monitoring exvivo cardiac ablation

Radiofrequency ablation for treatment of cardiac arrhythmia would benefit from real-time monitoring of ablation progress. Echo decorrelation imaging has been shown to predict local ablation but is susceptible to artifacts caused by heart motion. Here, a method for motion-corrected echo decorrelation imaging is tested in ex vivo ablation of bovine cardiac muscle with controlled motion. Experiments employed a Stockert 70 generator and a 4-mm Celsius catheter (Biosense Webster) with the ablation duration of 3min at the target ablation temperature of 90 °C, resulting in thermal lesions of diameter about 1 cm. Cyclical motion was induced by a stepping motor system (Velmex) with velocities of 0–10 mm/s in the travel range of 1.5 cm. Pulse-echo ultrasound images were acquired by an Acuson SC2000 scanner with a Z6Ms transesophageal matrix array (Siemens). Throughout ablation at intervals of 5–6 s, sequentially paired bi-plane images were acquired as complex (IQ) beamformed echoes with an interframe time of 9–13 ms. Regions of interest (ROIs), one including the catheter location and one outside the ablation zone, were tracked using detection of the myocardial wall boundary and spatial cross-correlation. Echo decorrelation within the ablation ROI was then mapped and compensated to remove motion-induced decorrelation measured in the reference ROI. Receiver operating characteristic curves characterize accuracy for predictions of local myocardial ablation by motion-compensated echo decorrelation imaging as a function of the induced motion amplitude.