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Echocardiogram Quantification: Quest for Reproducibility and Dependability

Reporter: Aviva Lev-Ari, PhD, RN

How can echo quantification become more reproducible and dependable?

 Senior Director, Global Cardiology at Innovations in Cardiology

Innovations in Cardiology

a subgroup of Innovations In Health on LinkedIn.com

Echocardiography encompasses an array of clinically important tasks including quantifying cardiac chamber size, ventricular mass and function.

Based on your experience, how can echo quantification become more reproducible and dependable?

Comments made by Group members:

 

Yoni TiroshYoni

Yoni Tirosh

CEO at M.I. Medical Incentive Ltd.

Hello Ivan,
I’ve sent you a personal message regarding an innovative development related to Echo use.

 

Tim ZepickTim

Tim Zepick

Office Manager; Technical Director, Ultrasound at Line Medical

It’s impossible.

There are large variations in quality of ultrasound systems. There are also large variations in skill levels of operators. And those skill levels change over time. But the most detrimental factor is that the human body is a dynamic and unique system. Some subjects are technically difficult and LV function is basically impossible to assess, even with an excellent US system. Measurement of LVPWiD is a guess on these patients. Then there are subjects on whom you can obtain excellent images at intercostal space #2, #3, and #4. And the anatomy is bisected at a different angle and might yield three different measurements at each approach. The same can be said for a lot of the 2-D length measurements. I can probably make your RA five centimeters wide, if I try.

That said, doing about 5,000 studies will get you pretty good at recognizing your limitations, realizing the need to remeasure erroneous data, common failings of ultrasound physics and other sources of error.

Thankfully, inexperienced techs get a good education on spotting and evaluating the “exciting” stuff because these nuanced stuff takes time to develop.

 

Wayne PetersonWayne

Wayne Peterson

Product Manager

Ivan,
As a former Philips employee, hello. My clinical skills included cardiac ultrasound. In response to your question, a software program with edge resolution enhancement and auto analysis would be amazing. It would remove user variability.

 

Tony GallagherTony

Tony Gallagher

Clinical Coordinator of Cardiology and Cardio-Pulmonary Rehabilitation at Floyd Medical Center

I agree with Tim that it is not possible. In deference to Wayne; edge recognition software would help. But the variety of equipment skill levels, even peoples varied vision; prevent 100% agreement.

Even at the larger conferences, when you attend the “read with the experts” courses, you see that they tend to disagree looking at the same images.

unless equipment, education, and criteria for performing studies gets standardized; not going to happen.

 

Alberto GomezAlberto

Alberto Gomez

Research Assistant at King’s College London

Reproducibility and reduction (I.e. not complete removal) of variability could be achieved in several ways. For example, to cite a few: multi view imaging to remove view dependency on edge definition and occlusion; angle independent flow quantification using 3D color Doppler; image fusion and compounding with tracked probes; simultaneous (or quasi-simultaneous) multi-prove systems. All these are engineering and research challenges but we will get to them. How long it will take highly depends on how willing manufacturers are to open up to research institutions and how willing research institutions are to share and exploit results.

 

Aviva Lev-Ari, PhD, RN

Aviva Lev-Ari, PhD, RN

Cardiovascular Original Research: Curation Methodology Designer at Leaders in Pharmaceutical Business Intelligence

Please visit us
Http://pharmaceuticalintelligence.com

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Justin Pearlman, MD, PhD, FACC

Thank you
Aviva Lev-Ari, PhD, RN

 

Clifford ThorntonClifford

Clifford Thornton

Echocardiography Technician at CapitalHealth

You’re a very brave man Ivan, asking the holy grail question of echocardiography! I’ve been doing echoes at prominent institutions for 10 years, been registered in echo since 2006, have performed probably more than 6,000 adult echoes, teach echo to technicians and sometimes residents, attended echo related conferences and read the latest Dr. Feigenbaum and Dr. Otto textbooks – so I can speak to this topic.

Here’s the deal. From what I understand, the best echo has to offer as far as EF quantification (which I think is usually the focus) is 3D volume quantification. The problem is, is that primarily due to reimbursement issues this technology has had very slow adoption and application and therefore low availability. A great application of this technology would be evaluating a patient for possible LVAD placement/treatment or heart transplant.

Given this, what most technicians are left with is 2 Dimensional echo. There are many ways we can measure Ejection Fraction with 2D Echo and they include direct 2D measurement (measuring the left ventricular internal dimension at end-diastole (LVIDd) and the left ventricular internal dimension at end-systole (LVIDs). Most modern echo systems have very specific packages that enable fairly easy measurements of these aspects of the heart and are clearly labeled. A technician can also make a similar measurement using M-Mode. The achilles-heel of M-Mode based measurement of EF is that the picture or the heart in the picture (from the parasternal long-axis window/view – PLAX) must be on-axis. If the picture is off-axis, your direct 2D measurements should be more accurate. Side note: this all goes out the window with a poorly trained or lazy echo tech who has little to no idea of what they’re doing – and unfortunately there’s too many of these out there (read more on this later). So, as far as 2D left ventricular dimension measurements of EF go, direct 2D (on screen) measurements are preferable.

According to a Wake Forest Cardiology conference which I attended several years ago in Orlando, “The Beat Goes On” the best or most accurate measurement of EF with 2D echo (assuming there’s a good, well-trained, knowledgeable and hard working echo tech performing the test) is with Simpson’s Bi-plane method/Quantification. This measurement is based on volume of blood in the heart at end-diastole and end-systole (see the pattern). Once this is calculated a technician can then calculate the stroke volume (which most packages calculate automatically once the proper measurements are calculated and entered) and the cardiac output (Stroke volume (SV) X heart rate (HR)). As a reference the heart wants to push around 5 liters of blood per minute to sustain life and normal body function. Of course this can greatly increase with exercise or decrease slightly with rest as can your respiratory function.

The way the Biplane Simpsons’ method is performed is that a technician calculates the following from both the apical-4-chamber view and the apical-2-chamber view (again most modern systems have these measurements built into the package and labeled and they can also be exported directly to the preliminary report through DICOM specs.):
1. Left ventricular volume at End-Diastole (LVVED) – A4C

1. Left ventricular volume at End-Systole (LVVES) – A4C

1. Left ventricular volume at End-Diastole (LVVED) – A2C

1. Left ventricular volume at End-Systole (LVVED) – A2C

Yes, you can imagine this is very time consuming. It can be done later once the scan is done however once the patient leaves, you can not go back and adjust your view if you think your picture is foreshortened or off-axis, etc.

Please see very relevant document to this topic from the American Society of Echocardiography, Committee Recommendations:
http://files.asecho.org/files/ChamberQuantification.pdf

 

Clifford ThorntonClifford

Clifford Thornton

Echocardiography Technician at CapitalHealth

cont’d–
The bottom line is that quantification in echo, particularly in calculating EF depends on the situation. Simpsons’ method is not performed routinely in most labs because if the EF visually looks normal (around 55% – 70%) from the long-axis, short-axis and apical 4 chamber and apical 2 chamber views then there’s usually not a huge need for it; little additional benefit. I try to do it as much as possible because I like to do as best an echo I can and also it’s good to practice and a little fun when you have very clear/great quality pictures (ironically these are the people who you know their EF is probably normal the minute they walk through your door!).

There are many tools and techniques one can employ to optimize their 2D/Simpsons’ EF measurements. Here are a few:
* the patient into the proper position (left lateral decubitus) — I use a wedge to keep them on their left side and keep their head well supported with a rolled up pillow or rolled up blankets

* the proper echo settings/frequency. Use penetration setting if you have to, but if they have good pictures, use the best resolution setting you can without sacrificing endocardial border definition — otherwise you’re defeating the purpose

* the proper breathing techniques (I find from parasternal window it’s best to have the patient inhale, exhale all the way and then hold their breath for loop acquisition and best to have them inhale and hold for apical acquisitions – but just play around with it until you get the picture you want).

* the picture on axis and avoid foreshortening — this is very key for the Simpsons’ method of discs

Now, you’ve tried all this, you’re sweating, your hand and shoulder are about to fall off, you see stars or angels or both and the patient and their family think you are completely clueless and think you’re torturing their Wife/Husband/Daughter/Friend/etc. and you’re wondering if you’ll have a job tomorrow. So what do you do?

Definity Echo contrast (Perflutren Lipid Microsphere) – http://www.definityimaging.com/ – you say? Yes, possibly. You need to A. Get the patient’s consent (although this is beginning to change) B. Establish IV access for the injection of the Definity solution C. Activate the Definity and use it within a certain period D. Utilize it correctly.

Basically Definity contrast is little gas bubbles that reflect the ultrasound beams (for which 2D pictures are generated from pulsed-wave doppler) very well or strongly and allow for a stronger, clearer/better resolution image. The heart walls/endocardial borders are one color and the contrast is the other (the contrast is usually the white-milky substance you see inside the left ventricle while it’s filling and contracting. Most people think it’s pretty “cool” when they see it and it can make a dramatic difference in how you visually estimate or calculate the EF. As I mentioned, Simpsons’ method (the preferred 2D EF calc. method) is highly dependent on operator skill and effort and hence picture quality. And Definity contrast can greatly enhance the picture quality. Last week I had a patient where you could barely see any endocardial border without Definity and visually estimating his EF would be a total shot in the dark. Well, we administered Definity, and I’m not lying it was still a tough scan, but once the Definity was injected and began to appear in the right ventricle and then left, I could see immediately that his EF was completely normal (55-60%). This was important to assess clinically because the patient was in the CCU at the time and he was s/p CABG. Judging whether the EF is normal or not can have a big play in clinical decision making for other conditions.

Ironically getting an accurate EF has to do more with having the right technician perform your test than it has to do with technology or anything else. And unfortunately there’s no lack of pitfalls there.

 

Reza

Reza Mehzad, MD, MPH

Mercy Heart Institute

Full automation for 3D echocardiography volume assessment AND having a safe contrast agents to be used with all echo studies.


 Clifford Thornton likes this

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Minimally Invasive Structural CVD Repairs: FDA grants 510(k) Clearance to Philips’ EchoNavigator – X-ray and 3-D Ultrasound Image Fused.

Curator: Aviva Lev-Ari, PhD, RN

 

UPDATED on 7/15/2018

The growing role of echocardiography in interventional cardiology: The present and the future

Open Access funded by Hellenic Cardiological Society
Under a Creative Commons license

Abstract

As structural heart disease interventions continue to evolve to a sophisticated level, accurate and reliable imaging is required for pre-procedural selection of cases, intra-procedural guidance, post-procedural evaluation, and long-term follow-up of patients.

Traditionally, cardiovascular procedures in the catheterization laboratory are guided by fluoroscopy and angiography. Advances in echocardiography can overcome most limitations of conventional imaging modalities and provide successful completion of each step of any catheter–based treatment. Echocardiography’s unique characteristics rendered it the ideal technique for percutaneous catheter-based procedures.

The purpose of this review is to demonstrate the use of the most common and up-to-date echocardiographic techniques in recent non-coronary percutaneous interventional procedures, underlining its inevitable and growing role, as well as illustrating areas of weakness and limitations, and to provide future perspectives.

SOURCE

https://www.sciencedirect.com/science/article/pii/S1109966617300258

 

On January 28, we reported on several FDA Pending 510(k) for The Latest Cardiovascular Imaging Technology

http://pharmaceuticalintelligence.com/2013/01/28/fda-pending-510k-for-the-latest-cardiovascular-imaging-technology/

On March 7, 2013 a very significant, pending clearance event, in favor of Philips Healthcare, was announced:

U.S. FDA Clears Philips’ EchoNavigator for Fused TEE-Angiography Image Guidance

March 7, 2013

March 7, 2013 — Philips Healthcare announced it has received 510(k) clearance from the U.S. Food and Drug Administration (FDA) for its EchoNavigator live image-guidance tool. The technology helps interventional cardiologists and cardiac surgeons perform minimally invasive structural heart disease repairs by providing an intelligently integrated view of live X-ray and 3-D ultrasound images.

Following the CE marking of EchoNavigator in Europe, Philips will now be able to introduce the system globally, with systems already installed in Europe and the United States.

EchoNavigator was developed in response to an upward trend in the use of both X-ray imaging and 3-D cardiac ultrasound imaging (echocardiography) during structural heart disease procedures — an area of interventional cardiology that is growing at around 40 percent per year. During such procedures, ultrasound imaging provides critical insights into the heart’s soft tissue anatomy, while X-ray imaging has particular strengths in visualizing the catheters and heart implants. EchoNavigator was designed to address the unique challenges associated with working with live X-ray and 3-D ultrasound images simultaneously.

“Together with Philips, we set out to bring two separate medical imaging techniques together in a way that provides clear visual guidance,” said John Carroll, M.D., interventional cardiologist, University of Colorado Hospital, Denver. “EchoNavigator is enabling us to use X-ray images combined with real-time 3-D ultrasound images to navigate catheters and deploy implants in the right position in the heart, making such treatments more straightforward.”

EchoNavigator will enable clinicians to perform procedures more efficiently by providing intelligently integrated X-ray and 3-D ultrasound images into one intuitive and interactive view, as well as providing easy-to-use system navigation and better communication between the multidisciplinary team carrying out the procedure.

“We have learned that ideally two live imaging technologies are needed to guide catheter-based repairs to the heart, and a multidisciplinary team is needed to perform it,” said Roberto Corti, M.D., interventional cardiologist, University Hospital Zurich, Switzerland. “This adds to the complexity of such procedures. The development of a more sophisticated imaging technology such as EchoNavigator will definitely provide us with a better understanding of the complex structures of the heart and their repair.”

“As the global market leader in interventional cardiology, we have worked with our partners to lead the way with pioneering solutions such as our real-time 3-D ultrasound technology and more recently our HeartNavigator navigation tool,” said Gene Saragnese, CEO for Imaging Systems at Philips Healthcare. “EchoNavigator is further evidence of our commitment to transforming healthcare through the introduction of innovations that enable best in class minimally invasive procedures.”

“In the emerging field of complex structural heart disease interventions, the information obtained by merging imaging technologies, as now possible with HeartNavigator and EchoNavigator, will be of tremendous value to the interventionalist, and in turn to the patient,” said Carlos Ruiz, M.D., director of the structural and congenital heart disease program, department of interventional cardiology, Lenox Hill Hospital, New York.

For more information: http://www.healthcare.philips.com

SOURCE:

http://www.dicardiology.com/article/us-fda-clears-philips’-echonavigator-fused-tee-angiography-image-guidance?goback=%2Egde_3693995_member_223204362

 With certainty we ascertain that:

3-D, 4-D Enhancements May Be the Future of Ultrasound

Written By:

Dave Fornell

May 15, 2012
A single-beat, short-axis 4-D echo imaged by GE’s Vivid E9. The system also offers software to reduce the number of clicks needed for exams. Photo courtesy of GE Healthcare

Hardware and software advances are enabling echocardiography to greatly expand its capability with increased quantification accuracy, ease-of-use, increased workflow efficiencies and wider use outside of echo labs. Today, cardiovascular ultrasound systems are being integrated into point-of-care for triage, and in operating rooms and cath labs for procedural guidance to cut the use of contrast and ionizing radiation. Advances in 4-D echo are making it an enhanced tool for structural heart evaluation and visualization during procedures.

3-D, 4-D Echo Advances

3-D echo images a volume of data (similar to a computed tomography [CT] dataset) rather than the traditional 2-D image rendering. These volumes can be manipulated with advanced visualization software just like a CT, slicing images on any plane and enabling the creation of 3-D images that can be rotated.

The proliferation of 3-D echo was previously handicapped by the large amount of labor involved in creating images from a volume dataset, explained Stephen Little, M.D., FRCPC, FACC, FASE, cardiovascular imaging section, department of cardiology, Methodist DeBakey. He said earlier generation systems required 30 or 40 mouse clicks to create an image.

“3-D required a lot of manual processing to slice and dice the images. It just took too long to do anything,” Little explained.

However, he said the newer 3-D systems are making the technology more viable with automation. He said echo is following the same path previously followed by CT advanced visualization software, where automation made a big difference in its wider market adoption for daily use.

Two big technology innovations have recently made 3-D and 4-D systems more commercially viable for everyday use. First, there has been a rapid increase in computing power in less expensive, smaller packages. Second, the automation of many advanced visualization functions drastically simplifies use and reduces the staff time required to manipulate volumes.

The introduction of 4-D echo (the fourth dimension is the addition of time) has opened new possibilities in ultrasound imaging. The analogy of 4-D is the difference between video and a still photograph. The technology allows 3-D images to be continuously updated for a live video view. The platforms with this feature require very fast processors to reconstruct large volumes of data into 3-D images over and over in milliseconds.

4-D ultrasound offers several advantages. It offers real-time color flow to assess hemodynamic information in the same heart cycle. It offers very accurate qualification of the left ventricle, free of geometric and shape assumptions used in 2-D echo. By using a 3-D volume of data, left ventricular wall motion tracking analysis can be done using the raw data volumes acquired. Vendors say this increases the accuracy of quantification.

It also offers multi-dimensional imaging, where operators can simultaneously acquire bi-plane and tri-plane images from the same heartbeat without moving the probe’s position.  This offers two or three different axis views concurrently or as a composite view of the heart in real-time, offering a new field-of-view that previously could not be obtained.  This helps acquire more information in fewer steps.

Real-time 4-D can produce images that are incredibly lifelike. This makes them easier to interpret and offers more meaningful information, including better procedural guidance. As technology continues to advance, 4-D echo will offer images comparable to CT 3-D reconstructions. Surgeons are now using 3-D echo reconstructions to aid procedural planning.

Use of 4-D greatly aids assessment of congenital heart diseases. Siemens recently introduced an updated version of its SC2000 cardiac ultrasound that quantifies volumetric color blood flow when evaluating holes in the heart (ASDs, VSDs, PFOs). The system uses a 3-D representation to show the true surface area and helps estimate the size of the holes for procedural planning.

Innovations in 4-D make possible real-time, comprehensive analysis of the beating heart during the entire cardiac cycle and allows even more detailed surgical-like views of the anatomy.

Toshiba’s new Aplio 500 shows the future of 4-D, where it can reconstruct volumes into color, fly-through video of vessel lumens. It works with peripheral vessels, but the heart is still too fast for the new technology to capture coronary vessels or ventricles. Image quality is similar to CT virtual colonoscopy.

Practical Application of 3-D

Methodist DeBakey Heart and Vascular Center has its own imaging center, which uses 3-D echo extensively. The center also images patients with both magnetic resonance imaging (MRI) and 3-D echo for comparative effectiveness research.

In the echo lab, 3-D echo is very good at estimating left ventricular ejection fractions (LVEF). However, there is a need for standardization between vendors before this technology will be used mainstream, Little said. Each 3-D echo machine is slightly different, so the workflow is not the same from vendor to vendor, and each requires use of proprietary workstations.

He explained 3-D offers a more accurate picture of cardiac function, but the basic concepts of 2-D echo still apply.

“3-D is not magic. It starts with a good 2-D image and you face all the same physics challenges as you do with 2-D technology,” Little said.

At DeBakey, echo contrast is often used to improve 2-D image quality when imaging obese patients, but they found 3-D has some limitations with contrast, said Miguel A. Quiñones, M.D., MACC, chairman, department of cardiology.  The software uses automated 3-D tracking of the borders of the ventricle, he explained, but the automated tracking system is confused by the contrast and has issues. However, an operator can overcome this by switching to a manual mode.

Little said hospitals need to assess whether there is a need for 3-D. “It depends on what they plan to do with the system. If you plan to use it for surgical procedures, then it might be worth investing in a 3-D system. If you are involved in activities with more emphasis on structural heart, then 3-D has a lot of application.”

Expanding TEE Use

Little said DeBakey makes extensive use of 3-D echo transesophogeal echo (TEE) to better guide mitral valve prolapse and regurgitation repairs, atrial septal defects (ASDs) and trans-aortic valve repair (TAVR). In TAVR, he said  TEE helps accurately place the angiographic pigtail catheter in the non-coronary cusp of the aortic root.  It also offers Doppler flow imaging to evaluate the hemodynamics of the valves and check for paravalvular leaks.

Little explained 3-D TEE offers a definite imaging advantage during complex interventions. The use of an X-plane (also referred to as bi-plane) TEE probe allows visualization from two different angles. He said these views are displayed on the main screen in a cath lab or hybrid OR to better visualize where a catheter or device is located in the anatomy more clearly than 2-D angiography. This helps with procedural navigation and in cutting the radiation dose from fluoroscopy.

“You can get two views simultaneously from two different perspectives, which helps speed things up,” Little said. “It adds a level of confidence to show you where wires and devices are inside the heart.”

DeBakey uses 3-D echo from various vendors, including Philips, GE and Siemens, but only the Philips system had offered 3-D TEE, Little said.

Siemens recently introduced syngo FourSight 3-D TEE. It can scan the whole heart in one volume instead of stitching two or three images to create a whole-heart image.

GE Healthcare also has a new 4-D  TEE system pending FDA review, which it previewed as a work-in-progress in March at American College of Cardiology (ACC) 2012 .

Comparison Chart

This article served as an introduction to the cardiovascular ultrasound systems comparison chart in the May-June 2012 issue of DAIC. Participants included:

Esaote North America –http://www.esaoteusa.com

GE Healthcare – http://www.gehealthcare.com

Mindray – http://www.mindray.com

Philips – http://www.philips.com

Siemens – http://www.medical.siemens.com

Toshiba – http://www.medical.toshiba.com

SOURCE:

http://www.dicardiology.com/article/3-d-4-d-enhancements-may-be-future-ultrasound

New Software to aid Interventional Cardiologists and Cardiac Surgeons in TAVI Procedures.

We covered the procedure and the technologies in the following curated article:

Clinical Trials on transcatheter aortic valve replacement (TAVR) to be conducted by American College of Cardiology and the Society of Thoracic Surgeons

http://pharmaceuticalintelligence.com/2013/02/12/american-college-of-cardiologys-and-the-society-of-thoracic-surgeons-entrance-into-clinical-trials-is-noteworthy-read-more-two-medical-societies-jump-into-clinical-trial-effort-for-tavr-tech-f/

TAVI Planning Software Introduced

Software enables selection of patients and access routes; aids procedure navigation, annulus sizing
Written By:

Dave Fornell

February 1, 2012
Philips received FDA clearance in December 2011 for its Heart Navigator TAVI planning and image guidance tool.
With the approval of the Sapien valve in November 2011, transcatheter aortic valve implantation (TAVI) technology is expected to revolutionize heart valve replacement with a minimally invasive procedure to replace open-heart surgery. However, it requires a good deal of planning, sizing and anatomical assessment of access routes using computed tomography (CT) scans with manipulation by advanced visualization software.
The success of this new procedure depends on correct patient selection and reliable pre-operative planning. In the conventional procedure, the necessary measurements are made during the actual surgery under direct visualization, but with TAVI, this can only be done pre-operatively with the aid of image data. A clear appreciation of the involved anatomy is crucial, and due to the fact that aortic anatomy is complex, 3-D visualization and measurement tools may enable more accurate and efficient pre- and post-intervention planning, which can be further enhanced with stereoscopic 3-D.At the 2011 Radiological Society of North America (RSNA) annual meeting, TeraRecon and Qi Imaging (formerly Ziosoft) both unveiled  TAVI planning and tool set software packages. The software helps automate manipulation of a CT dataset to quickly extract only the anatomy of interest and measurements, such as sizing of the aortic valve annulus and evaluation of clearance between the new valve and the right and left main coronary arteries. The software helps evaluate the aortic anatomy of patients to see if the route is clear for the larger delivery catheters required for the procedure. A heavily calcified aorta may disqualify a patient from the femoral access route.
Qi Imaging applied its super-computing, deformable registration software to its TAVI package, allowing lifelike motion of the cardiac cycle. This may offer a more accurate assessment of the motion of annulus for better valve sizing.
Philips Healthcare received FDA clearance in December for its HeartNavigator procedure planning and image guidance tool to help perform minimally invasive heart valve replacements. The technology merges pre-operatively acquired 3-D CT scans of the patient’s heart with the live interventional X-ray views. Using this technology, physicians can now simultaneously see the detailed 3-D anatomy of the patient’s heart together with the positioning of the catheter and the placement and deployment of the artificial valve.
TAVI has been available in Europe since March 2010. In August 2010, Siemens introduced its syngo Aortic ValveGuide in Europe to aid in TAVI procedures. It uses rotational angiography dataset images in the hybrid OR to help surgeons and interventional cardiologists navigate during transcatheter valve implantations. The software processes CT-like images of the heart from images acquired with the angiography system and creates 3-D overlay images on the live fluoroscopy. The software also finds the correct optimal C-arm angulation with a perpendicular view on the aortic root.
  • Siemens’ syngo Aortic ValveGuide aids TAVI navigation with rotational angiography image overlays.

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