Moderator: Elliot K. Fishman, MD
ELLIOT K. FISHMAN, MD: Thank you all for the informative presentations today. To conclude our session, I would like to get each pan-elist's advice for those who are just starting to do CT angiography. We have demonstrated incredible CTA applications, including: peripheral vascular disease, cardiac, kidney, aorta, pulmonary angiography, and pediatric imaging. But these tremendous opportunities are not as simple as they may seem to be. It is not just a matter of pushing a button!
So given that, while knowing that radiologists must go forward, we can share what we know, since we are all doing this on a routine basis. I would particularly like to hear your comments regarding the role of contrast in CTA andthe proper delivery of contrast.
GEOFFREY D. RUBIN, MD: My advice to anyone interested in beginning to perform CT angiography is just to do as much as they can to understand the operation of the CT scanner and the various responses to contrast medium delivery in the arterial beds that will be studied. As we move forward with CT technology to get faster and faster acquisitions, we are learning that new challenges arise in the different vascular beds; and they are frequently different challenges. By staying abreast of the new results in the literature and understanding the phenomena as they emerge, you are most likely to be able to address them and to optimize the quality of the images you acquire.
W. DENNIS FOLEY, MD: I have noted over the years that there has been a relatively steep learning curve for the average radiologist in understanding multidetector CT. I think that is improving now. But, I certainly encourage radiologists, if they have not paid attention to the technology, that they must really understand it now. If you understand the technology, then you can use it. As you mentioned, Elliot, contrast delivery is a critical issue. I think we have to be considered to be physiologists, as well as anatomic imagers.
I would also suggest that radiologists encourage technologists in their department to become aware of how MDCT works, and foster their interest in 3D imaging. That is an issue that we, as radiologists, also have to grapple with. We have to push the PACS vendors to incorporate 3D as part of the systems' routine operation.
We also must be able to use the workstations; but in partnership with our technologists who can do both routine and sophisticated 3D display. We do not have the time to do it all, particularly in the quantitative and segmentation aspect. So my advice is to address the technology, address contrast delivery, and work with the technologists. Then you have the technologists taking an active interest in participating in what we do.
U. JOSEPH SCHOEPF, MD: I agree with Geoff and Dennis. As radiologists, we should get the technical bases covered--That is our job. We need to know how our scanners and workstations work.
In addition to that, my advice would be to get in touch with the referring physicians. Radiologists should talk with them, see what their problems are, and see what they are dealing with everyday. If you learn about the questions they need answered with the diagnostic tests they are requesting from you, then you get an insight into the significance of information that you provide. I believe that is the surest way to secure credibility with your clinical partners, and it will also increase your business.
BRIAN R. HERTS, MD: I agree with everything that has been said. I would also like to point out that there are really two customers when you are doing CT angiography and 3D imaging. One is yourself; you are making diagnoses easier to do, so you can make faster and simpler diagnoses. The second customer is your referring physician. As Joseph said, you are really communicating information more effectively by doing CT angiography and postprocessing.
LEO P. LAWLER, MD, FRCR: It is fascinating to go around the table because we managed to get six physicians in the room to agree on a lot of things. It has been interesting to hear the dynamics of our discussion and to hear the presentations on different areas of the body. It seems to me that similar messages were coming out. One of the big messages is that, of course, multidetector CT is a great advance. In particular, we have addressed the impact of multidetector CT on the timing of contrast. I think everyone agrees that contrast timing is one of the biggest limitations in every organ, and it is going to get harder. So we have to get on top of that. It has to be a team approach with the radiologists and technologists.
I definitely would suggest consulting some resources, such as the material we are working on here. There are also some articles in the European literature that address contrast dynamics. They are a good place to start to understand this.
I would suggest moving from static organ imaging to pulsating structures. We still have limits with mechanical CT, particularly in the heart, and I would not start with CTA imaging of those structures.
For those who may still have any doubts, these talks have illustrated that to really harness the potential of multislice imaging, one must do 3D and, therefore, by definition, for segmentation, they must have optimal contrast boluses.
FISHMAN : The message that I would like to reinforce is that both radiologists and technologists need to know how to use the scanner.
I have always been a strong advocate of 3D and volume imaging. In 1986, we wrote an article that predicted that people would be using volume imag
ing within the next couple of years. Well, we were off by about 20 years. But as you look at 16-slice CT, then you look at 64-slice, the data sets are only going to get larger. Radiologists have to look toward the time when we will be looking at images as a volume. Axial CT is just not going to happen. I agree with Dennis that, right now, workflow is very bad. Many people have CT workstations or 3D workstations in one place, and PACS in another place. During the coming years, the big workstation vendors will be merging their systems; so we will have workstations with CT, 3D, and PACS in one place.
It is a very exciting time to be doing CTA. My advice to users is to just do it. We are not perfect, and there are lots of challenges. But there are also a lot of opportunities. We are learning and things are changing. But the best advice I can offer is that if you want to be doing CT angiography, and if you want it to remain in the realm of radiology, you have to be doing it today, and you have to be doing it well.Back To Top
Panel Discussion. Appl Radiol.