|
|||||||||||||||
|
Home
|
3D Ultrasound —
Volumetric Acquisition Provides More Data in Less Time While 3D ultrasound is common in prenatal imaging and screening, its use for clinical applications beyond obstetrics is just beginning to increase. But what does 3D imaging bring to the table that traditional 2D ultrasound can’t? Sonographers, physicians, and patients alike are learning firsthand how valuable the technology is in many facets of healthcare delivery. Among its obvious benefits is that physicians gain a better picture—literally—of what they are looking at. With 3D ultrasound, or volume imaging, capturing data volumetrically allows reviews from any plane. As such, the technology can be applied to clinical areas beyond obstetrics for more complete and accurate diagnoses. In addition, data from the ultrasound exams can now be saved, reviewed, or retrieved at a later time since the information is digitally stored as a volume. This has positive implications for following a patient over a course of treatment or reducing the need to repeat the ultrasound exam if more angles of the affected area are needed, as with 2D ultrasound. Further, both sonographers and patients are pleased with the speed with which volume acquisitions are completed, and facilities using 3D ultrasound can see the difference it makes in workflow. Gaining Traction Franklin N. Tessler, MD, CM, professor of radiology and chief of body imaging at the University of Alabama at Birmingham, is a strong proponent of 3D ultrasound technology and has been working with Philips Medical Systems. Compared with obstetrics, where it has been incorporated into protocols and long accepted for routine use, 3D ultrasound has yet to gain traction in other clinical areas, according to Tessler, but it’s something he believes will begin to take hold as benefits of the technology become more widely known. Richard Chiao of Siemens Medical Solutions agrees: “We believe 3D will be the future of ultrasound for the simple reason of its user capabilities. It’s difficult to get consistency with 2D ultrasound in capturing repeatable results, but 3D provides a way to mitigate that.” The availability of 3D ultrasound has been one limiting factor of what Tessler feels is important technology. He likens it to the early days of color Doppler machines in the late ‘80s when a facility may have had only one color Doppler machine among the remaining grayscale machines, and patients would be shifted to the color machine based on their case and need. Tessler says that facilities are generally still in that stage with 3D, with many having one to three 3D machines to complement their remaining six to 10 2D machines. “So for now, 3D is used selectively,” adds Tessler. In selecting who will be scanned using the 3D machine, Tessler says it’s important to take into account such things as whether the patient has already had 3D imaging or a case shows a need for more in-depth pictures. “Sometimes, a patient is done on a conventional machine, but various circumstances may necessitate looking at them on 3D,” says Tessler. With selective use, Tessler says the best exams to employ 3D technology include any areas surrounded by fluid, as it provides an excellent contrast. An example is the bladder, which is surrounded or filled with fluid. “We can see masses on the inner bladder walls with the 3D ultrasound,” says Tessler. Using 3D technology can also show aspects of vascular anatomy that have previously been unseen. “With 2D, we used to build a representation of the organ in our head based on what we saw in each individual view,” says Tessler. Now, with real-time 3D images, he says doctors can appreciate what wasn’t available with 2D. “In vascular anatomy, it works well because the structures are large enough to view. For example, large vessels in an aortic dissection are better viewed in 3D,” says Tessler. “You can tell what you’re looking at on a 2D ultrasound, but with 3D, it is much clearer to me and other physicians because we can rotate the view to see what we previously had to build mentally,” he adds. Workflow Kathy Sanguinetti, RDMS, RVT, ultrasound administrator with Radiologic Associates of Sacramento (Calif.) Medical Group, Inc. saw an immediate improvement in workflow and the number of patients the practice can image after purchasing five GE Healthcare machines in the spring. “It’s always been a challenge to accommodate patients in a timely manner; usually it would take two weeks for a patient to get an appointment, but often, as in the radiology field, you need tests sooner,” says Sanguinetti. “Once we went to the 3D machines, it took only five weeks to get the backlog down. Now, it only takes about two to three days to get in for an ultrasound,” she adds. Sanguinetti credits the sonographers for making that happen. “Once they got momentum, they didn’t want to stop,” she says. For example, when previously doing a transvaginal ultrasound with the 2D machines, the probe was inserted for approximately 10 to 15 minutes and the sonographer would freeze the frame and print each picture one by one. Now with volume imaging, the probe is inserted and pointed to the appropriate area, and the ultrasound sweeps through the organ manually or automatically to take the images. Sanguinetti notes it’s easier to schedule someone at the last minute knowing that a volume acquisition is being done because, rather than having to find a minimum 30-minute slot in the schedule, a 15-minute slot is all that may be needed and is much easier to accommodate. “Not everyone is a candidate for 3D, however. The 3D volume acquisition is only as good as the 2D image. A bad 2D image will not be better on a 3D image,” says Sanguinetti. More Than Just an Image At Radiologic Associates, once the 3D ultrasound is completed, the volume information is sent to an independent workstation where an experienced sonographer extracts essentials such as pathology, single photos, and other representative information. These are sent to a radiologist via PACS. The radiologist can also do a virtual rescan by scrolling through the volume acquisition information or reviewing it over the sonographer’s shoulder, which also reduces physician time. The advantage is that patients usually don’t have to be called back, and the 3D data provides more diagnostic material for the doctors. “We’re getting more than we’ve ever gotten before. Diagnostically, it’s giving us a lot more information,” says Sanguinetti. By integrating IT solutions with the diagnostic information, Bresenham agrees that it puts all the pieces of the puzzle together in a beneficial way. Ergonomics “Most strain is caused when documenting a case, where sonographers would have to push in on the probe to get each image,” says Bresenham. With the volumetric approach, they can collect the shots and proceed to a workstation to manipulate the images and complete documentation. “The sonographers love it,” says Sanguinetti, explaining that rather than holding a probe for 20 to 30 minutes at a time to capture each image separately for an exam, the time has been reduced to roughly 10 minutes to do volume acquisitions. “It’s changed the way we do ultrasound. I don’t see us ever turning back,” says Sanguinetti. Future Opportunities Tessler sees potential in using 3D ultrasound in the areas of biopsies and radiofrequency ablation (RFA). For biopsies, he explains, 2D usually suffices when positioning the point of a needle in a lesion. However, if the lesion is close to an interface that you don’t want to transgress, you must alternate between various perspectives until proper positioning is achieved. With 3D, one can effectively view multiple planes simultaneously, and positioning can be done more rapidly. In RFA, the doctor tries to position the tip of the probe and look at more than one point at a time. 3D ultrasound enables the physician to see, literally, the “whole picture,” but he adds, “it may take a few years to gain traction as 3D becomes more pervasive.” Chiao also mentions echocardiology as an area where 3D ultrasound can be applied with great success. “In this field, there is a need to look at complex geometry and to make measurements, and this kind of work suits 3D very well,” he says. Looking Ahead “This technology is so fluid, it’s changed a lot over the last year,” says Tessler. “It holds a lot of promise, and it’s really fun to play with and explore the technology.” He also mentions that in recent years, it has been more difficult to generate enthusiasm among radiology about ultrasound, but 3D ultrasound has sparked some renewed interest. In developing their technology, providers of 3D ultrasound are constantly looking for ways to improve their products. “We are developing into 3D from several different directions, including decreasing user entry variability, increasing workflow, and finding new applications that will improve patient care,” says Chiao. “It’s unusual to get a benefit for all key stakeholders,” says Bresenham, but she asserts that 3D ultrasound seems to achieve that: for patients in reducing imaging time, for sonographers in providing both ability to interact more with patients and ergonomic benefits, and for physicians who now have more comprehensive data to make clinical decisions. “It’s a technology that really makes sense to take a look at,” she adds. — Annie Macios is a freelance medical writer based in Doylestown, Pa.
|
|
3801 Schuylkill Rd • Spring City, PA 19475 Publishers of Radiology Today All rights reserved. |