4D Ultrasound: Seeing is Believing

The dimensions of ultrasound imaging are expanding, and women’s health is one area of medicine benefiting from the value of 3D and 4D. Using volumetric images as an adjunct to 2D ultrasound, physicians are expanding their diagnostic capabilities, boosting diagnostic confidence levels and consulting better with patients. With 4D in particular, physicians are using the element of time to further assess and diagnose obstetrical and gynecological conditions, adding more meaning to the saying — “seeing is believing.”

Volume ultrasound is playing a pivotal role in obstetrical care at Abington Memorial Hospital (AMH) in Abington, Pa. This 570-bed hospital offers a full range of comprehensive, high-level maternity services, delivers more babies than any other hospital in Eastern Pennsylvania, and excels in fetal diagnostics and perinatal testing.

Frank Craparo, MD, chief of the division of maternal/fetal medicine and genetics at AMH, specializes in perinatal consultation and frequently relies on the capabilities of 3D and 4D ultrasound. Craparo recalls one particular case involving conjoined twins in which volume sonography was extremely helpful.

Although the Mom was only in the very early stages of her first trimester, Craparo was reasonably confident from the 2D sonogram that she was going to give birth to conjoined twins. However, Craparo needed a way to help the expectant parents better visualize his diagnosis. At this stage in the twin’s development, they would only appear to be the size of peanuts on a monitor. “When we went to the fourth dimension, it was apparent that we had an early diagnosis of conjoined twins,” says Craparo.

Advanced 3D and 4D imaging techniques are valuable tools used in ultrasound today, particularly in women’s health. While 3D is a static volume image, 4D is a 3D image with the element of time. For example, imaging in 4D allows sonographers and physicians to visualize the fetus in movement.

Volume sonography is proving to have significant clinical utility in improving diagnostic efficiencies, as well as helping to counsel expectant parents. An increasing number of women’s health centers are now using 3D and 4D tools on their premium ultrasound systems as a complement to their 2D imaging capabilities.

Sonographers and perinatologists at AMH image in 3D and 4D using Siemens Medical Solutions’ Acuson Antares with fourSight 4D ultrasound technology. “We use it when we think it will enhance the diagnosis,” says Craparo. “There are certain abnormalities we are suspicious of and the 4D rendering really does assist in clarifying them. A classic example is a cleft lip.”
 
Birth defects occur in one in 33 births. Volume ultrasound is used for assessing and diagnosing certain congenital fetal abnormalities such as malformations of the face, limbs, skeletal structures and organs. On the other hand, 3D and 4D also are being used in gynecology to detect structural problems of the uterus and diagnose ovarian tumors, endometrial polyps, and fibroids.

“3D and 4D are another layer of our diagnostic capability, and hopefully they will help us expand and refine our abilities to make a diagnosis,” says Craparo.


Enhancing diagnostic capabilities

The Center for Maternal-Fetal Medicine (CMFM) in Las Vegas is on board with 4D ultrasound, too. Providing nearly 65 percent of all the perinatology services to the Las Vegas community, the practice consists of four perinatologists who scan on average 25 to 30 women daily. They utilize the Philips Medical Systems’ iU22 intelligent ultrasound system.

According to Maternal Fetal Medicine Specialist Brian Iriye, MD, the center provides consultation for high-risk ultrasound or problems in pregnancy. “We pride ourselves in keeping our equipment at the latest and greatest, which allows us to improve our diagnostic capacity as well as to have quicker examination time,” says Iriye. “If you have better equipment, you can find the view that you need more quickly and continue with the exam.”

Physicians at CMFM presently image in 4D to get a better view of external anomalies, including fetal facial features and spinal defects, hand and feet abnormalities and skeletal dysplagia. Iriye hopes to one day utilize volume sonography to assess and diagnose congenital heart abnormalities. “I think 3D and 4D for perinatologists are becoming something absolutely necessary,” says Iriye. “Most of our diagnoses are made with 2D imaging. But 3D and 4D only enhance our capability in trying to find fetal anomalies, and also enhance our communication with the patients.”

The Fetal Diagnostic Center (FDC) of Pasadena, Calif., acquires volumetric images in real-time with GE Healthcare’s Voluson 730 and the portable Voluson i. Greggory DeVore, MD, a fetal and maternal specialist and director of the center, uses both systems to provide consultations for nearly 400 obstetricians who refer patients to him annually. He mostly evaluates the fetus for fetal problems.

“Both 3D and 4D enhances our diagnosis because it improves our ability to see more clearly certain types of things, such as skeletal abnormalities,” says DeVore. “We may use it to look at spina bifidia. We may use it to look at the heart. We can look at the facial bones for cleft palate. We can look at the suture lines of the skull. We can turn on the color Doppler with the 3D/4D to look at the surface anatomy of the placenta and where the blood vessels are going.”


The patient side

In obstetrical applications, volume ultrasound complements 2D imaging by enhancing diagnostic capabilities. “I don’t know that there is anything that we can not see with 2D that we can see with 4D,” says AMH’s Craparo. “It’s more of an adjunct technology used in addition to 2D to solidify the diagnosis.”

Studies have been conducted to see if there are any workflow savings related to the capture of volumetric ultrasound images, but users say it’s too soon to tell.

Three-D and 4D ultrasound should add only a few minutes to a complete exam, if used efficiently, DeVore emphasizes. Everyone must spend time learning how to use the technology in an efficient manner to experience key benefits, he says.

“There is a learning curve,” DeVore continues. “You can not just jump in immediately and know how to use [3D/4D] technology. Users have to take the time to understand the technology and how to use it. Users have to learn about the concept of 3D imaging — how they would acquire the image, interpret it, and slice and dice the volume to understand the images that they are seeing.”

Volumetric images are oftentimes used in ultrasound for patient consultation and reassurance. CMFM’s Iriye says there have been a number of instances where 3D/4D has been a great tool for fetal abnormality consulting with his patients. “For instance, two pregnant mothers have come to me for second opinions within the past year — one baby had a spinal abnormality and the other a club foot deformity,” Iriye recalls. “The parents did not believe the [initial diagnosis]. But when I was able to show them in 3D and 4D, they were able to deal with the problem that they had and seek the care that they needed.

“When a patient looks at the 3D or 4D image as opposed to the 2D image, she believes that your diagnosis is true,” he continues. “Patients are much more apt to believe you and not feel like they have to get a second opinion because they can see it directly in front of them. Telling patients that something is abnormal with the most important being in their life is the hardest part of my job. That is where the importance of 3D and 4D really comes to play.”


Playing catch-up

Users of 3D and 4D ultrasound for obstetrical applications say the technology will eventually play a significant role in the early diagnosis of congenital heart defects, which are present in about 1 percent of live births, according to the American Heart Association. The fetal heart is difficult to image, but physicians are certain they will some day play catch-up with the advent of increased processing power, better transducers and advanced software.

“I think the biggest role that 3D and 4D will play is in the acquisition of abnormal fetal hearts,” says CMFM’s Iriye.” The fetal heart is probably the most difficult organ to image. With 4D imaging, eventually [physicians and sonographers] are going to be able to get to a point where they can make an acquisition and look for the abnormality by slicing the plane.”

Advances made in 3D and 4D ultrasound will continue to further their clinical role in obstetrics and gynecology. “As it has improved, 4D has become one of the more exciting technologies in the field of ultrasound,” says Craparo. “When it first came out there was the ‘wow factor.’ I think now 3D and 4D are transitioning from the ‘wow factor’ to determining how we can use the technology clinically. As vendors keep improving the technology, I think the diagnostic capabilities in making diagnoses and refining them, particularly in the evaluation of the heart, will make some dramatic differences.”