Abdominal Imaging

For expectant parents, a prenatal ultrasound provides the first glimpse of their child. Ultrasound has long been used to provide a window into the womb – and more importantly – as a diagnostic test for fetal abnormalities.

Ultrasound uses high-frequency sound waves transmitted through the abdomen. The echoes from the waves are recorded and translated into video or still images of the baby. Until recently, these images were limited to two-dimensional (2D) views. In recent years, the development of ultra-fast computer systems and software, along with advanced imaging technology has allowed clinicians to perform ultrasounds in three and four dimensions (3D and 4D, which is a moving animation of 3D images).

3D Ultrasound

3D Ultrasound

3D and 4D Ultrasound Technology at Penn
At Penn, 3D and 4D ultrasound technology is being used by the maternal fetal medicine (MFM) physicians at the Hospital of the University of Pennsylvania and Pennsylvania Hospital. Both hospitals care for high-risk pregnancies to identify potential complications that could harm the baby and/or mother. Penn radiologists also perform ultrasounds during pregnancy.

Penn is equipped with the very latest 3D- and 4D-capable machines. Specially trained obstetrician/gynecologists use these machines to detect fetal abnormalities of the face and body. High-quality detailed images of the nose, ears and limbs often aid physicians in the diagnosis of deformities that may have gone unnoticed in the 2D images.

"Two dimension looks only at surface structure – we are constantly ‘chasing the baby’ to take pictures. Three D provides the ability to look at three 90 degree planes at the same time. We can maneuver through and combine these three different views – the result is a more complete image with more information. This allows us to detect fetal anomalies like cleft lip and clubbed feet much easier. It also helps patients better conceptualize what their baby will look like. The parents, obstetrician and pediatrician are more prepared to care for the baby after birth. It allows us to give a ‘heads up’ so that no one is shocked at the delivery," said Eileen Wang, MD, obstetrician/gynecologist and maternal fetal medicine specialist at the Hospital of the University of Pennsylvania.

The 3D ultrasound is also able to scan a baby’s tissue and organs. Through a technique called ‘volume acquisition,’ STIC (spatial temporal image correlation) technology is used to rotate around the heart and provide different views. With 2D technology, volume acquisition was difficult to see because the fetal heart beats very rapidly. Penn maternal fetal medicine specialists work with pediatric cardiologists to better assess and diagnose abnormalities of the heart. The 3D machine also uses Doppler technology, which measures motion, to assess blood flow in various organs and placenta.

Captivating 4D Imaging

Perhaps the most captivating feature of the new ultrasound technology used at Penn is 4D imaging. Four-dimensional imaging combines many 3D images over time to show the baby’s movement. Parents and doctors can view body functions and detailed facial expressions. A yawn, grimace or lack of movement gives insight into physical condition and strengthens the parental bond with the infant. If an invasive procedure is necessary, 4D imaging is utilized for guidance.

Although many parents of healthy babies inquire about having a 3D ultrasound, Dr. Wang emphasizes the targeted use of 4D technology is for diagnostic purposes.

"This is a procedure for high-risk pregnancies that should be used only when medically necessary. It is not a new form of baby entertainment but rather a very specialized technique which should be administered only by trained healthcare staff in a hospital or ambulatory care setting," Dr. Wang said.