Angio CT : The Creation of a Dynamic Combination

Today’s Angio CT was developed from the original concept of Dr. Yasuaki Arai, the former Director of National Cancer Center Hospital, Tokyo, Japan. From as early as the 1980s, he realized the benefits of combining a C-arm with CT. The first ‘Angio CT’ was developed based on Dr. Arai’s idea together with the collaboration of both CT- and Angio Teams from Toshiba Medical (currently known as Canon Medical Systems) in 1992.

Canon Medical’s Mr. Atsushi Gotoh, Senior Manager, X-ray Systems Business, Promotion Department, X-ray Systems Division, and Mr. Satoshi Oota, CT Systems Development, Department, CT Systems, Division, are former members of the R&D team for Angio CT, who worked on the system’s initial development and introduction. Together with Mr. Ryuji Zaiki, Senior Manager, and Mr. Kashu Yuto Senior Global Marketing Manager of Vascular Systems Marketing and Promotion Department, Vascular Systems Division., they reflect on the journey that started more than 30 years ago.

Could you tell us about the developmental stages of Angio CT?
How did it all start?

Mr. Gotoh: About 32 years ago, we started the development of Angio CT. We wanted to ensure that the two completely different systems worked together.

What technical challenges were encountered in this project?

Mechanical synchronization was our first challenge.
The CT team had a lot of technical challenges to deal with.
Our CT engineers had to develop a mechanism to move very heavy objects mounted on the gantry.
The main challenge for the Angiography system engineers was to rotate the ceiling C-arm structure layout by 90°.*
Of course, there were some functional changes needed.
CT systems are gantry-based, and development related to the gantry requires a great deal of careful design, including deciding how the sensor needs to be, and how the rails can be laid completely level with the floor. We also invested a lot of effort into careful site-planning and construction work.

We had to make sure that the rails are embedded with no protrusions, in order to avoid creating a trip hazard and prevent objects from catching on protrusions.
In addition, as the systems are installed at hospitals, where there is the possibility of liquids, such as disinfectants or blood, entering the rail grooves, we also had to factor in a way to keep the rails clean.
We had to make sure that liquids could be easily removed using swabs or mops. This was particularly challenging in the development of the Angio CT. Engineers came up with a special design for the rails, in which liquids are prevented from entering the rail grooves easily, and yet, the liquids that do enter can easily pass through to the bottom.

*: In Canon Medical’s Alphenix 4D CT, the ceiling C-arm lands perpendicular to CT gantry rail, so the C-arm can be fully parked without disturbing CT fluoro procedures

What is most rewarding to you in this project?

Mr. Gotoh: When I receive positive comments from users of our systems, such as "The system was very easy to use," or "This system changed the whole examination procedure." One physician from Chicago University in the USA remarked that the system is economically extremely efficient. These comments indicate that our initial objectives for design of the system have been successfully achieved in real clinical settings.

When I hear these things, I regard the development as a success.

Are there any other achievements that you are particularly proud of in the development?

Mr. Gotoh: Yes. The Angiography system controls travel of the CT system. Not the operation of the system itself, but the movement of the CT from one place to another.
The motors and other mechanisms related to movement are installed in the CT, but the command is sent from the Angiography system.
During the developmental stage, we found it exciting to see if the system would travel appropriately according to the retraction command or traveling command.
This requires the separate CT system and Angiography system to communicate with each other. Successfully programming the commands was one of the most important achievements for us.
We designed the circuit -the printed wiring board (PWB) - to enable this communication.

And as we needed to make sure that the program worked appropriately before attempting to move a huge system, like a CT, we created models to simulate the CT (Figure 1).
Using these models, we simulated communication with the CT system via the circuit that we designed. According to the communication rules that were established collaboratively by the CT- and Angio teams, we first performed a simulation separately for the CT system and the Angiography system using the model. Then we combined the two models and performed a simulation.

Figure 1

After confirming that communication worked successfully, we then set up the actual CT and Angiography systems in the test bay. Seeing the actual system starting to move was a very happy moment. As an engineer, it was very rewarding and encouraging. We then moved on to detailed design.

"These comments indicate that our initial objectives for design of the system have been successfully achieved in real clinical settings."
Mr. Atsushi Gotoh, Senior Manager, X-ray Systems Business Promotion Department., X-ray Systems Division.

Anecdotes behind the development.

What further changes were made during the detailed design process?

Mr. Gotoh: We adapted the blue LED to our latest controller when we updated the first generation Angio CT to Infinix generation because the blue LED was invented and was introduced as a new technology of the world. (Figure 2) You designed this, didn’t you?

Mr. Oota: Yes.

Figure 2

Angio CT system with multi-slice CT in 2003.

Mr. Gotoh and Mr. Oota were members of the original development team for the Angio CT. They describe history behind the invention.

What was the most challenging part of the development?

Mr. Oota: In the beginning, the CT team had not previously extensively collaborated with teams from other modalities, and as a consequence, did not know everything about the other systems.

Mr. Gotoh: Yes, both CT- and Angio teams were developing at the same time. When something failed, we would begin a discussion to find out which was the responsible modality.

Mr. Oota: The Angio team got into many deep discussions with the CT team back then. When an issue came up at the hospital, we investigated thoroughly to find out exactly what was happening.

Mr. Oota: One particular issue was in constructing the interface, because it was difficult to ascertain which system was responsible for what in the tests. It was a lot of fun to build something together with another modality.
Although I now ‘belong’ to the CT team, it’s still fun to collaborate with the Angio team, from the ‘other side’, as it were.

Do you have any comments on the systems that we now have thanks to these developments?

Mr. Oota: It’s nice to know that Angio CT has developed in the way that it has. Back then, it was a totally new concept, and we couldn’t imagine how it would be implemented in the future. However, now it’s become a standard. That’s a pleasant surprise!

Mr. Gotoh: The success has been made possible by Dr. Arai’s passion.

Mr. Oota: Yes. Thanks to this, we were able to form the connection with the hospital and share information with them towards developing the system by implementing it in clinical environment.
The Angio CT could only be created with the ideas, expertise and help of Dr. Arai.

Mr. Zaiki: The CT - and Angio teams are working even closer together now.

Mr. Oota: Yes. That has intensified since we formed the ‘IVR CT project team’. It inspired us to work more closely together.

Mr. Zaiki: There is a difference in the CT images for diagnosis and for treatment.

Mr. Oota: Oh yes, the requests are different. And this makes a lot of sense.
Their purpose is different and utilization as well. So there are special needs that the CT team has to respond to.

Mr. Oota: I spent a lot of my efforts on site planning, I also had to go to the construction site to collect the data of the floor construction.

Mr. Oota: So we changed the depth of the floor installation rail.

Mr. Gotoh: Yes, it was deeper, but was made shallower.

Mr. Zaiki: However, thanks to that, when some competitors couldn’t fit their systems in the room because they needed a taller room, the customer came to us for a solution.

Mr. Oota: Yes, and they have a large box of cables in the ceiling. We are the only manufacturer to produce a system without anything above. It’s all inside the floor.

Mr. Gotoh: We sometimes call competitor's structure a 'chimney' and it moves with the system’s arm.

"Back then, it was a totally new concept, and we couldn’t imagine how it would be implemented in the future."
Mr. Satoshi Oota, Senior Principal Engineer, CT Systems Development Department., CT Systems Division.

So, our system is all embedded in the floor?

Mr. Oota: Exactly.

Then you must be involved with the construction of the room?

Mr. Kashu: Yes, the construction and planning. Other systems require use of the ceiling.

So, it’s easier for the hospital to have the flfloor modifified rather than the ceiling?

Mr. Oota: It’s not easy. For the ceiling installation, it’s simpler to install and faster, but they must reinforce the ceiling and have the space.

Mr. Gotoh: Yes, they can’t install the surgical lighting system in the ceiling in exchange.

Mr. Gotoh: All cables of our system CT is installed in the floor. (Figure 4)

Figure 4

You mentioned that there were more challenges asides from the mechanical ones, could you tell us more about them?

Our next challenge after the mechanical part was the integration of imaging and clinical concept.
We received a lot of requests from Dr. Arai concerning inclusion of positional information etc.
Dr. Arai has a unique perspective that is totally different from ours. For example, there was one request on linkage between CT and Angiography images. This was very tough to solve.
These were challenging issues, but they have now all been resolved, making fusion of CT and Angiography images possible.
This achievement was not only the result of inspiration, but also collaborative efforts between multiple departments.

What expectations do you have for the future of Angio CT?

Mr. Gotoh: The future also involves Dr. Arai. While our systems are premium class, Dr. Arai has always strongly believed that a wonderful system like this should be used in many countries around the world.
To make this possible, Dr. Arai always had in mind that the system should be available in budget-oriented versions so that it can also be used in developing countries, as well as developed countries. This made us realize how much potential the system has.

Is there anything you'd like to say to the users of our systems?

Mr. Gotoh: I want to say thank you. Thank you for using our systems! It is not our role to specify in what way the system should be used. This is totally up to the users.
Our system is still evolving, and has great potential. If our users come up with new and innovative ideas of how the system can be used therapeutically, we'd be more than happy to work with them on it. I want to explore what can be done if the combination of CT and Angiography is further strengthened and used at a higher level.
I will strive to realize ideas that can deliver further innovation in healthcare.//

In Japan alone there are over 200 systems installed since it was invented.
This is all made possible thanks to input from the users of our systems. Achieving a combined Angiography system and CT system is an example of an innovation that has been driven from the customer side.
We value 30 years of partnership, and look forward to collaborate with clinical care team to transform global health care.

Atsushi Gotoh
Senior Manager, X-ray Systems Business Promotion Department., X-ray Systems Division.

Satoshi Oota
Senior Principal Engineer, CT Systems Development Department., CT Systems Division.

Ryuji Zaiki
Senior Manager, Vascular Systems Marketing and Promotion Department., Vascular Systems Division.

Yuto Kashu
Senior Global Marketing Manager, Vascular Systems Marketing and Promotion Department., Vascular Systems Division.

Interviewer: Amalia Airi Asai
Global Integrated Marketing Communications specialist VL/XR, Clinical Solutions & Modality Marketing Group., Global Marketing Department.

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