Live Fluoroscopic Images Research Articles

Model-free control for autonomous prevention of adverse events in robotics.

Introduction: Preventive control is a critical feature in autonomous technology to ensure safe system operations. One application where safety is most important is robot-assisted needle interventions. During incisions into a tissue, adverse events such as mechanical buckling of the needle shaft and tissue displacements can occur on encounter with stiff membranes causing potential damage to the organ. Methods: To prevent these events before they occur, we propose a new control subroutine that autonomously chooses a) a reactive mechanism to stop the insertion procedure when a needle buckling or a severe tissue displacement event is predicted and b) an adaptive mechanism to continue the insertion procedure through needle steering control when a mild tissue displacement is detected. The subroutine is developed using a model-free control technique due to the nonlinearities of the unknown needle-tissue dynamics. First, an improved version of the model-free adaptive control (IMFAC) is developed by computing a fast time-varying partial pseudo derivative analytically from the dynamic linearization equation to enhance output convergence and robustness against external disturbances. Results and Discussion: Comparing IMFAC and MFAC algorithms on simulated nonlinear systems in MATLAB, IMFAC shows 20% faster output convergence against arbitrary disturbances. Next, IMFAC is integrated with event prediction algorithms from prior work to prevent adverse events during needle insertions in real time. Needle insertions in gelatin tissues with known environments show successful prevention of needle buckling and tissue displacement events. Needle insertions in biological tissues with unknown environments are performed using live fluoroscopic imaging as ground truth to verify timely prevention of adverse events. Finally, statistical ANOVA analysis on all insertion data shows the robustness of the prevention algorithm to various needles and tissue environments. Overall, the success rate of preventing adverse events in needle insertions through adaptive and reactive control was 95%, which is important toward achieving safety in robotic needle interventions.

The effect of stiffness and hole size on nipple compression in infant suckling.

During infant feeding, the nipple is an important source of sensory information that affects motor outputs, including ones dealing with compression of the nipple, suction, milk bolus movement, and swallowing. Despite known differences in behavior across commercially available nipples, little is known about the in vivo effects of nipple property variation. Here we quantify the effect of differences in nipple stiffness and hole size on an easily measured metric representing infant feeding behavior: nipple compression. We bottle-fed 7-day old infant pigs (n = 6) on four custom fabricated silicone nipples. We recorded live X-ray fluoroscopic imaging data of feeding on nipples of two levels of hardness/stiffness and two hole sizes. We tested for differences in nipple compression at the nipple's maximum compression across different nipple types using a mixed model analysis of variance. Stiffer nipples and those with smaller holes were compressed less than compliant nipples and nipples with larger holes (p < 0.001). We also estimated the force applied on the nipple during feeding and found that more force was applied to the compliant nipple with disproportionately larger strains. Our results suggest that infant pigs' nipple compression depends on material type and hole size, which is likely detected by the infant pigs' initial assessment of compressibility and flow. By isolating nipple properties, we demonstrated a relationship between properties and suckling behavior. Our results suggest that sensory information affects feeding behaviors and may also inform clinical treatment of poor feeding performance.

Real-time respiratory motion compensated roadmaps for hepatic arterial interventions.

During hepatic arterial interventions, catheter or guidewire position is determined by referencing or overlaying a previously acquired static vessel roadmap. Respiratory motion leads to significant discrepancies between the true position and configuration of the hepatic arteries and the roadmap, which makes navigation and accurate catheter placement more challenging and time consuming. The purpose of this work was to develop a dynamic respiratory motion compensated device guidance system and evaluate the accuracy and real-time performance in an in vivo porcine liver model. The proposed device navigation system estimates a respiratory motion model for the hepatic vasculature from prenavigational X-ray image sequences acquired under free-breathing conditions with and without contrast enhancement. During device navigation, the respiratory state is tracked based on live fluoroscopic images and then used to estimate vessel deformation based on the previously determined motion model. Additionally, guidewires and catheters are segmented from the fluoroscopic images using a deep learning approach. The vessel and device information are combined and shown in a real-time display. Two different display modes are evaluated within this work: (1) a compensated roadmap display, where the vessel roadmap is shown moving with the respiratory motion; (2) an inverse compensated device display, where the device representation is compensated for respiratory motion and overlaid on a static roadmap. A porcine study including seven animals was performed to evaluate the accuracy and real-time performance of the system. In each pig, a guidewire and microcatheter with a radiopaque marker were navigated to distal branches of the hepatic arteries under fluoroscopic guidance. Motion compensated displays were generated showing real-time overlays of the vessel roadmap and intravascular devices. The accuracy of the motion model was estimated by comparing the estimated vessel motion to the motion of the X-ray visible marker. The median (minimum, maximum) error across animals was 1.08mm (0.92mm, 1.87mm). Across different respiratory states and vessel branch levels, the odds of the guidewire tip being shown in the correct vessel branch were significantly higher (odds ratio=3.12, p<0.0001) for motion compensated displays compared to a noncompensated display (median probabilities of 86 and 69%, respectively). The average processing time per frame was 17ms. The proposed respiratory motion compensated device guidance system increased the accuracy of the displayed device position relative to the hepatic vasculature. Additionally, the provided display modes combine both vessel and device information and do not require the mental integration of different displays by the physician. The processing times were well within the range of conventional clinical frame rates.

Real-time intraoperative co-registration of transesophageal echocardiography with fluoroscopy facilitates transcatheter mitral valve-in-valve implantation in cases of invisible degenerated bioprosthetic valves.

Transcatheter mitral valve-in-valve (TMViV) implantation is an alternative treatment to surgery for high-risk patients with degenerated bioprosthetic mitral valves. Some types of bioprostheses are fluoroscopically translucent, resulting in an 'invisible' target deployment area. In this study, we describe the feasibility and outcomes of this procedure using intraoperative fusion of transoesophageal echocardiography (TEE) and live fluoroscopy to facilitate valve deployment in cases of invisible bioprosthetic valves. We reviewed all TMViV implantations at our centre from July 2014 to July 2019. Patient, procedure and outcome details were compared between those with a visible bioprosthesis (N = 22) to those with an invisible one (N = 12). Intra-operative TEE and live Fluoroscopy co-registration were used for real-time guidance for all invisible targets. All valve implantations were completed successfully in both groups without cardiovascular injury, valve migration or left ventricular outflow-tract obstruction. Technical success was 100% in both groups. One-year survival was 83% [95% confidence interval (CI) 70-96] for the entire cohort, with 79% (95% CI 63-100) survival for the visible group and 92% (95% CI 77-100) for the invisible group. Probability of 1-year survival free from mitral valve reintervention, significant valve dysfunction, stroke or myocardial infraction was 78% (95% CI 63-93) for all patients whereby the probability was 72% (95% CI 54-97) in the visible group and 80% (95% CI 59-100) for the invisible group. The use of intraoperative TEE and live fluoroscopy image fusion facilitates accurate TMViV among patients with a fluoroscopically invisible target-landing zone.

The effect of artificial X-rays on C-arm positioning performance in a simulated orthopaedic surgical setting.

We designed an Artificial X-ray Imaging System (AXIS) that generates simulated fluoroscopic X-ray images on the fly and assessed its utility in improving C-arm positioning performance by C-arm users with little or no C-arm experience. The AXIS system was comprised of an optical tracking system to monitor C-arm movement, a manikin, a reference CT volume registered to the manikin, and a Digitally Reconstructed Radiograph algorithm to generate live simulated fluoroscopic images. A user study was conducted with 30 participants who had little or no C-arm experience. Each participant carried out four tasks using a real C-arm: an introduction session, an AXIS-guided set of pelvic imaging tasks, a non-AXIS guided set of pelvic imaging tasks, and a questionnaire. For each imaging task, the participant replicated a set of three target X-ray images by taking real radiographs of a manikin with a C-arm. The number of X-rays required, task time, and C-arm positioning accuracy were recorded. We found a significant 53% decrease in the number of X-rays used and a moderate 10-26% improvement in lateral C-arm axis positioning accuracy without requiring more time to complete the tasks when the participants were guided by artificial X-rays. The questionnaires showed that the participants felt significantly more confident in their C-arm positioning ability when they were guided by AXIS. They rated the usefulness of AXIS as very good to excellent, and the realism and accuracy of AXIS as good to very good. Novice users working with a C-arm machine supplemented with the ability to generate simulated X-ray images could successfully accomplish positioning tasks in a simulated surgical setting using markedly fewer X-ray images than when unassisted. In future work, we plan to determine whether such a system can produce similar results in the live operating room without lengthening surgical procedures.

The benefit of combined carbon dioxide automated angiography and fusion imaging in preserving perioperative renal function in fenestrated endografting

BackgroundContrast-induced nephropathy is a possible adverse event in fenestrated endovascular aneurysm repair (FEVAR). Automated carbon dioxide (CO2) angiography has been proposed as an alternative to iodinated contrast medium (ICM) for standard endovascular aneurysm repair; however, its use in FEVAR has not yet been investigated. The aim of this study was to analyze the possibility of reducing the amount of procedural ICM during FEVAR by combining CO2 with intraprocedural three-dimensional preoperative computed tomography angiography images overlaid on two-dimensional live fluoroscopy images (fusion imaging [FI]). MethodsBetween January and April 2018, juxtarenal and pararenal abdominal aortic aneurysms and type IV thoracoabdominal aortic aneurysms undergoing FEVAR with a CO2 + FI protocol were prospectively collected and compared with FEVAR cases treated with standard procedural imaging (ICM + FI) between June and December 2017. Preoperative, intraoperative, and postoperative data were analyzed. Amount of ICM, procedure and fluoroscopy time, total radiation dose (dose-area product), endoleaks, and technical success (defined as absence of type I or type III endoleak and target visceral vessel patency at completion angiography) were assessed. The 30-day renal function worsening (estimated glomerular filtration rate reduction >25% of the preoperative value) and 6-month reinterventions were also considered. Analysis was done by Fisher exact and Mann-Whitney tests. ResultsForty-five patients were enrolled, 15 (33%) managed by CO2 + FI and 30 (67%) by ICM + FI. The two groups were homogeneous in their clinical, anatomic, and endograft features. Median ICM administration was significantly lower in CO2 + FI compared with ICM + FI (41 mL [interquartile range (IQR), 26 mL] vs 138.5 mL [IQR, 88 mL]; P = .001). There was no difference in median procedure time, fluoroscopy time, and dose-area product between CO2 + FI and ICM + FI. Intraoperative type I or type III endoleak detection was similar (P = 1) in CO2 + FI (7%) and ICM + FI (7%), with immediate repair and technical success achieved in all cases. Early type II endoleak did not differ in the two groups (CO2 + FI, 27%; ICM + FI, 20%; P = .7). Postoperative renal function deteriorated in two patients (13%) in the CO2 + FI group vs eight patients (27%) in the ICM + FI group (P = .04). The median increase of postoperative creatinine concentration was smaller in the CO2 + FI group than in the ICM + FI group (0.09 mg/dL [IQR, 0.03 mg/dL] vs 0.3 mg/dL [IQR, 0.4 mg/dL]; P = .04). The median hospitalization time was shorter in the CO2 + FI group (5 days [IQR, 1 day] vs 8 days [IQR, 4 days]; P = .002). No reintervention was necessary at 30-day and 6-month follow-up in either group. ConclusionsCO2 + FI is safe and effective in FEVAR and allows the amount of ICM to be significantly reduced, leading to shorter hospitalization time and better renal function preservation at 30 days. Technical success, procedure and fluoroscopy time, radiation dose, and 6-month reinterventions are comparable with those of the standard ICM imaging protocol for FEVAR. Based on this preliminary experience, CO2 + FI may be proposed as an effective tool to reduce the overall amount of procedural ICM, with consequent benefits on perioperative renal function.

Accuracy of Realtime Overlay for Aneurysm Repair in Awake Patients

Introduction - Fusion imaging, which provides image guidance by overlaying preoperative 3D vessel anatomy from the preoperative CT scans onto live fluoroscopic images, is being used in endovascular repair to decrease radiation and contrast dose (1). Cloud-based image tracking software has been shown to be more accurate than hardware-tracking systems in these procedures(2). The aim of this study is to determine the accuracy of this technique when patient movement is greatest, for procedures done under local or regional anaesthesia.

Novel augmented physical simulator for the training of transcatheter cardiovascular interventions.

Training in transcatheter cardiovascular skills today represents a significant challenge because of the complexity of the interventions and an extensive use of multiple live imaging technologies. We describe the design, the face validation, and content validation of a newly developed physical transseptal puncture (TSP) simulator using additive manufacturing techniques and novel imaging simulation solutions. The TSP simulator contains a femoral vein catheterization pad, silicon phantoms of the venous system, a replaceable interatrial septum, and cameras to mimic live fluoroscopic and echocardiographic imaging. A validation study was conducted at the University Hospital of Zurich. A total of 14 interventional cardiologists and cardiac surgeons assessed the TSP simulator. Participants performed a TSP on the simulator using standard interventional tools. Face and content validity was demonstrated using a 5-point Likert scale. The TSP simulator is a new training tool for transcatheter cardiovascular interventions. All interventional cardiologists and cardiac surgeons completed the training exercise and scoring. Overall impression was rated (out of 5) 4.04 ± 1.03, haptic feedback scored 4.13 ± 0.82, and the realism of fluoroscopy simulation 4.39 ± 0.79. Usability was rated 4.50 ± 0.63 by the participants, indicating that the simulator could be suitable for training. We demonstrated face and content validity of a new simulator for transcatheter cardiovascular interventions. The TSP simulator's usability, haptic feedback, imaging solutions, and the overall impression of its usage were reported as very realistic. The TSP simulator represents a promising tool for simulation-based training using real interventional toolkits in a mimicked radiological environment.

The anterior approach for conversion hip arthroplasty.

Conversion of prior proximal femoral fracture fixation to hip arthroplasty is a fairly common and successful procedure, necessitated by various modes of failure. The procedure is well described utilizing a posterior or anterolateral surgical approach. The anterior approach for total hip arthroplasty has gained in popularity. The approach allows for supine positioning and facilitates live fluoroscopic imaging. We present possible advantages and disadvantages, as well as the surgical technique, of conversion to total hip arthroplasty via the direct anterior approach.

The 70° Supinated Oblique View: A Cadaveric Analysis to Determine Ideal Radial Styloid Screw Position in Locked Volar Plating of Distal Radius Fractures.

Background: Defining an intraoperative radiographic view to best determine the radial styloid screw position in locked volar plating of distal radius fractures may improve fixation and aid in decreasing cortical penetration and implant complication. We used a cadaveric model to demonstrate a reproducible, oblique radiographic view to identify the radial styloid screw position. Methods: Nine fresh-frozen elbow-to-fingertip cadavers were used for this study. A 2.4-mm variable angle volar distal radius locking plate was applied to the distal radius. A Kirschner wire (K-wire) was inserted into the radial styloid through the plate. Placement of the K-wire through the tip of the styloid at the cortical edge was confirmed through a separate radial incision. A second K-wire was placed through the radius shaft into the ulna to aid in angular measurements. Live fluoroscopic imaging was used as the forearm was brought from full 90° of supination toward neutral. Once the K-wire was abutting the cortical edge, rotation ceased, and a goniometer was used to measure the angle of forearm rotation. This was repeated for a total of 3 repetitions on each specimen. Results: The average angle of supination best depicting the position of the radial styloid screw was 68.5° (range = 64.3°-70.5°). Conclusions: Radial styloid screw fixation in locked volar plating of distal radius fractures increases the ultimate strength to failure, but screw penetration and tendon irritation can occur. The 70° supinated oblique intraoperative view provides the most accurate evaluation of the position of the radial styloid screw.

NOVEL AUGMENTED FLUOROSCOPIC IMAGING PLATFORM ACCURACY ASSESSMENT DURING NAVIGATION BRONCHOSCOPY IN SIMULTANEOUS COMPARISON WITH CONE BEAM CT AND RADIAL EBUS

NOVEL AUGMENTED FLUOROSCOPIC IMAGING PLATFORM ACCURACY ASSESSMENT DURING NAVIGATION BRONCHOSCOPY IN SIMULTANEOUS COMPARISON WITH CONE BEAM CT AND RADIAL EBUS

A Numerical Preoperative Planning Model to Predict Arterial Deformations in Endovascular Aortic Aneurysm Repair

Endovascular aneurysm repair is rapidly emerging as the primary preferred method for treating abdominal aortic aneurysm. In this image-guided interventional procedure, to obtain the roadmap and decrease contrast injections, preoperative CT images are overlaid onto live fluoroscopy images using various 2D/3D image fusion techniques. However, the structural changes due to the insertion of stiff tools degrade the fusion accuracy. To correct the mismatch and quantify the intraoperative deformations, we present a patient-specific biomechanical model of the aorto-iliac structure and its surrounding tissues. The predictive capability of the model was evaluated against intraoperative data for a group of four patients. Incorporating the perivascular tissues into the model significantly improved the results and the mean distance between the real and simulated endovascular tools was 2.99 ± 1.78mm on the ipsilateral side and 4.59 ± 3.25mm on the contralateral side. Moreover, the distance between the deformed iliac ostia and their corresponding landmarks on intraoperative images was 2.99 ± 2.48mm.

MR-guided Cardiac Interventions.

Diagnostic and interventional cardiac catheterization is routinely used in the diagnosis and treatment of congenital heart disease. There are well-established concerns regarding the risk of radiation exposure to patients and staff, particularly in children given the cumulative effects of repeat exposure. Magnetic resonance imaging (MRI) offers the advantage of being able to provide better soft tissue visualization, tissue characterization, and quantification of ventricular volumes and vascular flow. Initial work using MRI catheterization employed fusion of x-ray and MRI techniques, with x-ray fluoroscopy to guide catheter placement and subsequent MRI assessment for anatomical and hemodynamic assessment. Image overlay of 3D previously acquired MRI datasets with live fluoroscopic imaging has also been used to guide catheter procedures.Hybrid x-ray and MRI-guided catheterization paved the way for clinical application and validation of this technique in the assessment of pulmonary vascular resistance and pharmacological stress studies. Purely MRI-guided catheterization also proved possible with passive catheter tracking. First-in-man MRI-guided cardiac catheter interventions were possible due to the development of MRI-compatible guidewires, but halted due to guidewire limitations.More recent developments in passive and active catheter tracking have led to improved visualization of catheters for MRI-guided catheterization. Improvements in hardware and software have also increased image quality and scanning times with better interactive tools for the operator in the MRI catheter suite to navigate through the anatomy as required in real time. This has expanded to MRI-guided electrophysiology studies and radiofrequency ablation in humans. Animal studies show promise for the utility of MRI-guided interventional catheterization. Ongoing investment and development of MRI-compatible guidewires will pave the way for MRI-guided diagnostic and interventional catheterization coming into the mainstream.

A prospective observational trial of fusion imaging in infrarenal aneurysms

ObjectiveUse of three-dimensional fusion has been shown to significantly reduce radiation exposure and contrast material use in complex (fenestrated and branched) endovascular aneurysm repair (EVAR). Cydar software (CYDAR Medical, Cambridge, United Kingdom) is a cloud-based technology that can provide imaging guidance by overlaying preoperative three-dimensional vessel anatomy from computed tomography scans onto live fluoroscopy images both in hybrid operating rooms and on mobile C-arms. The aim of this study was to determine whether radiation dose reduction would occur with the addition of fusion imaging to infrarenal repair in all imaging environments. MethodsAll patients who consented to involvement in the trial and who were treated with EVAR in our center from March 2016 until April 2017 were included. A teaching session about radiation protection and Cydar fusion software use was provided to all operators before the start of the fusion group enrollment. This group was compared with a retrospective cohort of patients treated in the same center from March 2015 to March 2016, after a dedicated program of radiation awareness and reduction was introduced. Ruptured aneurysms and complex EVAR were excluded. Preoperative and perioperative characteristics were recorded, including parameters of radiation dose, such as air kerma and dose-area product. Results were expressed in median and interquartile range. ResultsForty-four patients were prospectively enrolled and compared with 21 retrospective control patients. No significant differences were found in comparing sex, body mass index, and age at repair. The median operation time (wire to wire) and fluoroscopy time were 90 (75-105) minutes and 30 (22-34) minutes, respectively, without significant differences between groups (P = .56 and P = .36). Dose-area product was nonsignificantly higher in the control group, 21.7 (8.9-85.9) Gy cm2, compared with the fusion group, 12.4 (7.5-23.4) Gy cm2 (P = .10). Air kerma product was significantly higher in the control group, 142 (61-541) mGy, compared with 82 (51-115) mGy in the fusion group (P = .03). The number of digital subtraction angiography runs was significantly lower in the fusion group (8 [6-11]) compared with the control group (10 [9-14]); (P = .03). There were no significant differences in the frequency of adverse events, endoleaks, or additional procedures required. ConclusionsWhen it is used in simple procedures such as infrarenal aneurysm repair, image-based fusion technology is feasible both in hybrid operating rooms and on mobile systems and leads to an overall 50% reduction in radiation dose. Fusion technology should become standard of care for centers attempting to maximize radiation dose reduction, even if capital investment of a hybrid operating room is not feasible.

Advanced image processing with fusion and calcification enhancement in transcatheter aortic valve implantation: impact on radiation exposure.

Radiation exposure is a concern for both patients and operators during transcatheter aortic valve implantation (TAVI). Efforts to reduce radiation dose are warranted. We aimed at investigating if per-operative advanced image processing can reduce patient and operator irradiation use during TAVI. We performed a prospective single-centre observational study comparing patient and operator radiation exposure using standard fluoroscopy (control group) or a novel technology of live advanced fluoroscopic image processing (test group) among consecutive patients undergoing TAVI between August 2015 and April 2016. Patient irradiation (dose-area product, effective dose and air kerma), contrast media volume and clinical outcomes were assessed. Among 152 elderly [median age (interquartile range): 83 (78-87)] patients (n = 76 per group) undergoing TAVI, baseline clinical characteristics were similar between the control and test groups, except for a higher median EuroSCORE II (2.8% vs 2.3%, P = 0.02) and higher rate of TAVI for failing surgical bioprosthesis (11.8% vs 2.6%, P = 0.03) in the control group. The dose-area product was reduced in the test group: mean reduction of -27.5 Gy × cm2 [95% confidence intervals (CIs): 15.9-39.1, P < 0.001]. Furthermore, effective dose [mean reduction -6.5 (95% CI: 5.9-7.2) mSv, P < 0.001] and air kerma [mean reduction -167.5 (95% CI 163.4-177.3) mGy, P < 0.001] were lower in the test group. Fluoroscopy time, contrast volume and clinical outcomes were similar. Patient radiation exposure was significantly reduced using a novel live advanced fluoroscopy image processing with calcification enhancement and fusion of the virtual aortic annulus without compromising patient safety.

"Vascular Outlining": Augmented Imaging for Transfemoral Access-A Preclinical Investigation.

Advanced visualization software tools have been used in clinics to improve the safety and accuracy of transcatheter procedure. Imaging techniques have greatly evolved during the era of transcatheter aortic valve implantation (TAVI). In a retrospective analysis, we investigated the feasibility of augmented fluoroscopy for iliofemoral access using a novel "Vascular Outlining" roadmapping technology. The Vascular Outlining prototype device (Philips Healthcare) application was used with iliofemoral angiography of 10 patients undergoing transfemoral TAVI. The software processes any conventional angiographic sequences, extracting the static outline of vessels and projecting the two-dimensional vessel margins as a roadmap on live fluoroscopy. Post-processed results were clinically assessed to determine whether the technical performance of the tool is sufficient. Augmented imaging was possible in all investigated angiography sequences. The analysis of software-generated images showed accurate projection of the two-dimensional outline of the iliofemoral vessels as an overlay on the live fluoroscopy image in most cases. Overlay inaccuracy was only observed in cases with low contrast or patient movement. In static and contrasted angiography sequences, "Vascular Outlining" showed accurate image overlay. We identified that the quality of the vascular outline is dependent on the opacification of the contrast injection and the stability of the patient on the table. With further development. this application might increase the accuracy of femoral puncture and reduce the incidence of vascular complications. Clinical trials are needed to confirm these hypotheses.

A new approach of three-dimensional guidance in paediatric cath lab: segmented and tessellated heart models for cardiovascular interventions in CHD.

Optimal imaging is essential for catheter-based interventions in CHD. The three-dimensional models in volume-rendering technique currently in use are not standardised. This paper investigates the feasibility and impact of novel three-dimensional guidance with segmented and tessellated three-dimensional heart models in catheterisation of CHD. In addition, a nearly radiation-free two- to three-dimensional registration and a biplane overlay were used.Methods and resultsWe analysed 60 consecutive cases in which segmented tessellated three-dimensional heart models were merged with live fluoroscopy images and aligned using the tracheal bifurcation as a fiducial mark. The models were generated from previous MRI or CT by dedicated medical software. We chose the stereo-lithography format, as this promises advantage over volume-rendering-technique models regarding visualisation. Prospects, potential benefits, and accuracy of the two- to three-dimensional registration were rated separately by two paediatric interventionalists on a five-point Likert scale. Fluoroscopy time, radiation dose, and contrast dye consumption were evaluated. Over a 10-month study period, two- to three-dimensional image fusion was applied to 60 out of 354 cases. Of the 60 catheterisations, 73.3% were performed in the context of interventions. The accuracy of two- to three-dimensional registration was sufficient in all cases. Three-dimensional guidance was rated superior to conventional biplane imaging in all 60 cases. We registered significantly smaller amounts of used contrast dye (p<0.01), lower levels of radiation dose (p<0.02), and less fluoroscopy time (p<0.01) during interventions concerning the aortic arch compared with a control group. Two- to three-dimensional image fusion can be applied successfully in most catheter-based interventions of CHD. Meshes in stereo-lithography format are accurate and base for standardised and reproducible three-dimensional models.

Augmented 3D venous navigation for neuroendovascular procedures

BackgroundEndovascular venous access is increasingly used for the treatment of many cerebrovascular diseases. The quality of venous roadmapping through arterial injection can be problematic because of contrast media dilution, slow...

073_16806-K1 Use of Dynamic Coronary Roadmap for Positioning Left Ventricular Lead : First Case Report

Dynamic Coronary Roadmap (DCR) is a navigation support package that allows the users to see a roadmap of the coronary anatomy displayed on live fluoroscopy. By comparing moving structures that are present in both the angiogram and the live fluoroscopy images, with image registration techniques, DCR

A Planning and Guidance Platform for Cardiac Resynchronization Therapy.

Patients with drug-refractory heart failure can greatly benefit from cardiac resynchronization therapy (CRT). A CRT device can resynchronize the contractions of the left ventricle (LV) leading to reduced mortality. Unfortunately, 30%-50% of patients do not respond to treatment when assessed by objective criteria such as cardiac remodeling. A significant contributing factor is the suboptimal placement of the LV lead. It has been shown that placing this lead away from scar and at the point of latest mechanical activation can improve response rates. This paper presents a comprehensive and highly automated system that uses scar and mechanical activation to plan and guide CRT procedures. Standard clinical preoperative magnetic resonance imaging is used to extract scar and mechanical activation information. The data are registered to a single 3-D coordinate system and visualized in novel 2-D and 3-D American Heart Association plots enabling the clinician to select target segments. During the procedure, the planning information is overlaid onto live fluoroscopic images to guide lead deployment. The proposed platform has been used during 14 CRT procedures and validated on synthetic, phantom, volunteer, and patient data.