Patience and Imagination... is what it once took to explain to prospective parents what they were seeing in an ultrasound image of their baby-to-be. That has changed remarkably in the last 10 years, largely due to the pioneer work of Dr. Dolores Helen Pretorius, professor of radiology at UCSD, whose research with physicist husband Thomas Nelson paved the way for three-dimensional ultrasound that produces pictures of full fetuses whose heads, and even the tuck of an ear or chin, can be viewed from all angles.
Viewed by computer, these three-dimensional images, the latest in sonogram technology, can be rotated so that an organ or body part can be viewed in slow motion or real time. This major advance in diagnostic imaging, developed by Pretorius and Nelson, is being used around the world to make pictures of tumors, brains, hearts, blood vessels and other parts of the human anatomy once subject to two-dimensional images, in which data was assembled in cross slices. Comparing and arranging the information was a mental exercise in imagining how the whole would look by putting all the parts together.
Volume data, obtained by attaching a position-tracking device to a sensor so the computer can accurately align the slices to be shown from any angle, are not only more understandable to the human eye, their use can also verify any lack of abnormalities. There are less than 20 places in the United States, and only three on the West Coast, including UCSD, using 3-D ultrasound.
Pretorius came to UCSD in 1979 as a resident in radiology, after obtaining her medical degree from Baylor College of Medicine in Houston. She served a fellowship at the University of Colorado Health Sciences Center in Denver and taught there for four years, then left to join UCSD in 1986 as an assistant professor in the department of radiology. From 1992 to 1994, she entered private practice, returning to UCSD two years later.
Study of the fetus has been Dr. Pretorius' specialty since she was introduced
to the field by her mentor, Dr. Michael Manco-Johnson, chair of the University
of Colorado radiology department, where she served her fellowship. "It
was a new, burgeoning field, to study the fetus and find anomalies,"
said Pretorius, who was part of an initial group of obstetricians, pediatricians,
radiologists and other specialists studying how to identify and describe
the fetus and document changes. "It was something brand new. No one
knew how to do it," she added. "You couldn't do it in isolation.
You needed a team approach."That same approach characterizes her work today, in which she is radiology director for the UCSD Fetal Center and also works under the Hillcrest hospital's obstetrics department. The sharing of data among several sites is a developing area of concentration for Pretorius. "We can read images from Thornton Hospital as well as Hillcrest if we need to," she said. "I can help my residents on the Internet. It's a whole new thing that's happened in the last few months at our institution. Accessing images through the Internet off web sites has made life more flexible in the way we can help each other as colleagues."
The biggest challenge for her has been juggling family life and professional life. Pretorius and Nelson, 51, have two teenagers. "My solution has been flexibility," Pretorius said. "I try to build in flexibility. In radiology, one of the nice things is that you can find another faculty member to cover for you for an hour and come back and finish the work." She and her husband have also returned late at night and on weekends to build in research time. "For any woman, combining family life with work is challenging. While radiology may have more women than other specialties, I don't think meeting that challenge is any different from other fields," she said.
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