Recently, Applied Radiology had the opportunity to speak with Arnd Kaldowski, Vice President of Global Sales and Marketing, Ultrasound Division at Siemens Medical Solutions (Malvern, PA) about the future of ultrasound technology.

Applied Radiology: What is the current status of ultrasound technology in clinical practice and where is its development heading?

Arnd Kaldowski: We believe that ultrasound (US) has made quite some progress over the last few years. But, if you look at its impact on clinical workflow and on changing standard clinical practice, US has not had the impact during the last 10 years that other modalities that are in more innovative phases have had. When looking at opportunities, it is important to focus on what can be changed in the clinical workflow by applying the technology rather than by developing a technology for the sake of technology.

AR: Are you saying that development should be driven by applications?

AK: Absolutely, it should focus on which new clinical US applications can be identified and which developments can improve workflow by offering higher diagnostic confidence as well as improvements in throughput and user independence.

AR: What indications are you most focused on?

AK: Breast cancer screening is one area of very high interest at the moment; going from diagnosis to early detection. It is well-known that US, especially in dense breasts, has the ability to be very specific with regard to identifying potential tumors, but it has not yet been fully developed. You need to be able to perform a fast examination with a relatively high degree of standardization to be able to do a screening process.

There are a lot of new opportunities for US with the use of targeted agents and patient-specific molecular imaging. Molecular imaging with US is based on today's contrast approach with bubbles, whereby active agents, or biomarkers, are placed on a bubble to hook to a specific ligand or enzyme to identify specific areas of interest.

AR: What are the potential applications for molecular US?

AK: There is work being done to identify tumor angiogenesis very early on, before you can see the tumor. That is one application that we are pursuing. Another one, in a very different direction, is called sonothrombolysis. In this process, you send the contrast bubble to a thrombus and, through an active agent, attach the bubble to the thrombus. Then you can destroy the bubble with a high-intensity US beam that starts to dissolve the thrombus. You can use a targeted agent or just use the collapse of the bubble. You could even fill the bubble with a medication, deliver it with a targeted agent to a specific area of interest, and make the bubble burst and deliver the drug targeted to the specific area.

AR: What is silicon US?

AK: We acquired a company last year that has developed, to a prototype level, transducers based not on piezoelectric material but on silicon technology. It is possible to build nanotechnology structure on silicon. With silicon, you can build a drumhead-a cavity-and keep the silicon standing around it. You then can put connectors on top of it and, by applying a certain amount of electricity and voltage, you can make the drumhead send sound waves.

AR: What are the benefits of this technology?

AK: With this technology, you can go to a very large number of elements per square cm or mm, far more than you have on today's piezoelectric transducers. With that, you can go to a real-time 3-dimensional transducer. Secondly, the signal bandwidth of the transducer is a lot better, so you get better resolution and sharper images. The third benefit is that you can integrate the first step of the signal processing in the silicon and then build the silicon drum. Unlike today's transducers, this new technology will allow some of the signal processing within the transducer, even though it is lighter than today's transducer. Also, it will not need a radiofrequency (RF) cable from the transducer to the system. So the cable can be lighter and it can have more channels sending more information to the system. A big limitation for US is the need to connect the RF cable to the piezoelectric material. That limits you in the number of elements you can use, and it also limits you with regard to weight and ergonomics. By pushing the signal processing to the front in the silicon, you get rid of a lot of the problems.

AR: Where is silicon US in the developmental process?

AK: Currently, we have prototypes working on today's products. We are learning about the images and how to optimize them. I would assume that we are approximately 1 to 2 years out from the first commercial availability. The first implementation is really using the advantages of the technology for today's transducers, but you can think further. One dream, based on the ability to have large silicon US plates, would be to develop a belt-type transducer that can be placed around the neck, but that is much further in the future. Step one is to apply this technology to today's transducers; in step two, the benefits of this technology will guide us to different forms of transducers.

AR: What other issues are important to US today?

AK: One that is important for us is the integration of US into a broader modality perspective. If you talk about fusion of modalities, one area that we see as very important is how you utilize the capabilities of US in combination with computed tomography (CT) or magnetic res

onance (MR) imaging. If you can combine some of the advantages of CT, for example, with US during an operative procedure and fuse the information, especially with regard to image-guided therapy, there are a lot of opportunities for ultrasound to either cover ground that is not currently covered or to replace some of the X-ray-centric approaches. The whole element of intraoperative imaging and image-guided therapy is a huge field in which we see a lot of opportunities.

AR: What are the goals of the Innovation Center that Siemens opened in Mountain View, CA?

AK: We opened the Innovation Center last July with 2 main goals. On one hand, we wanted to invite our customers to participate in our decision making regarding which new applications and new technologies we should ultimately invest our money in. If you have an idea like silicon US, it might be 3 years before you have a product available. There are a lot of decisions you have to make. The Innovation Center is clearly focused more on discussions on what will happen in US in 3 to 5 years, on what needs to happen from a clinical perspective, and on getting more guidance early on as to whether or not we are addressing the right topics.

The second goal is to have exposure on a continuous basis as an organization, especially as a product-development organization, and to gather input from customers so that the solutions we develop will be more targeted to the real needs of the customer. I think that exposing all of our employees to customers on an almost daily basis is really the best way of getting us to the best level of a customer-centric approach.

SOAR Awards for Excellence in Cardiac CT

In other news, Applied Radiology , Siemens Medical Solutions, and the Society of Cardiovascular Computed Tomography (SCCT) have joined together to present the SOAR Awards for Excellence in Cardiac CT.

Designed to identify future thought leaders in cardiac CT, 8 outstanding third-year residents (4 each in cardiology and radiology) have been selected to enter research papers on cardiac CT into the competition. Each author will research a specific clinical topic and will write a detailed article, including diagnostic and therapeutic objectives, imaging protocols, outcome data, and cost-effectiveness of cardiac CT within the assigned topic. The papers will be judged by a panel of experts, and the 2 top papers-1 from the cardiology fellows and 1 from the radiology fellows- will be selected. The winners will each receive a 1-year fellowship to continue their research in cardiac CT and a trip to the SCCT Annual Scientific Meeting. All accepted papers will be published in a supplement to Applied Radiology later this year.

The members of the review committee are: SCCT President Stephan Achenbach, MD, Erlangen, Germany; Suhny Abbara, MD, Boston, MA; Michael Poon, MD, New York, NY; Elliot K. Fishman, MD, Baltimore, MD; and Allen J. Taylor, MD, FACC, Washington, DC.