His paintbrush and his scalpel

War forced him to flee from his homeland in Vietnam. Imperial, Neb., took him in. "Sesame Street" and other children's TV shows taught him English. But it was art that gave a young Hiep Nguyen a voice as a refugee in a strange land.

"My very first painting, which I still have . . . is of an isolated wheat plant in the midst of this snowstorm," Nguyen, a surgeon at Children's Hospital Boston, said in his office one recent afternoon. "The snow meant you didn't know where you were going. You did not know what was around you."

Nguyen's ability to express himself through art stayed with him as he rose from a refugee of the Vietnam War to become one of the few pediatric urologists in the world.

Now he's hoping his art will help break down barriers in developing countries that impede the care of children with urological problems and congenital abnormalities -- and contribute to earlier treatment of the smallest patients.

"Nature is wonderful, which is why we do the work we do," said Nguyen, a South End resident whose unassuming manner gives no hint of his impressive resume, dedication to global volunteerism, and artistic flair. "But sometimes things don't develop correctly, and that's when sometimes we have the opportunity to intervene and make things better."

Children in the United States benefit from the expertise from doctors like Nguyen, who detect -- even before birth -- treat, and manage problems early, he said.

But in developing countries, he said, such problems are often untreated until much later because they are not considered critical, said Josh Wood, an administrator at International Volunteers in Urology who has coordinated trips with Nguyen.

Nguyen, 40, is working to reverse that pattern through his work with the Utah-based group, whose mission is to educate and train doctors and to treat patients -- including children -- worldwide.

Its mission has taken Nguyen and other volunteers to Mongolia, Ghana, Nepal, and Cuba.

Wood said Nguyen has an amazing reputation. "He really cares about the people he is serving, but he also cares about the volunteers, to make sure they get a valuable education," Wood said in a telephone interview from Utah. "He's impressive, but he's also down to earth."

Nguyen, who serves as lead surgeon and team leader on some trips, also helps train doctors to detect and treat common urological problems early in children that can cause bedwetting and urinary tract infections.

They also repair nature's defects. For instance, they fix male and female genital abnormalities, such as a condition in boys called hypospadius, which is corrected by placing the opening at the tip of the penis. In Africa, they form vaginas for girls who have none. Many of those girls are labeled defective and frowned upon, Nguyen said, but by reconstructing the vagina, the doctors help make the girls "whole again."

As pediatric urologists, "we make lives better," said Nguyen, whose easygoing nature warms even the toughest little critics to open up about sensitive problems.

"In children this is extremely important," he said. "You know how merciless children can be when they see differences. They often tease you, and I know that from personal experience because they tease you because you look different. But what if you had the opportunity to make them look like everybody else, to make them normal . . . so all those scars from childhood never take place. This is where urology is so much fun."

Nguyen understands what it means to feel different. After fleeing Vietnam, his family settled in Imperial, where his father was being recertified as a doctor to fill a shortage there.

The people were nice, but there were obvious gaps.

No one looked like them. No one spoke their language. A teacher tagged him as Bob because Hiep was too difficult to pronounce. The name stuck. Art helped him cope.

Over the years, his English improved, and so did his artwork. Nguyen used to give his art away. But friends were wowed. They insisted on paying for them. One paid $5,000 for a painting, he said. And the requests keep coming.

He is painting a series on sleep, focusing on the backs of subjects. He has been commissioned to work on a series based on the ballet "Swan Lake."

In one unfinished work, a ballerina sits, her skirt fans around her, her arms clasped in front, her head bowed as she waits for her prince. In another in the same series, the woman -- part swan, part ballerina -- looks longingly into the face of her dead prince.

When his artwork sells, Nguyen said, the proceeds go to the international group to help its mission. Nguyen, who has volunteered with the group for the past five years, said the group plans to return to Ghana and his native Saigon to continue its training mission.

In the meantime, Nguyen is busy working for and with children. He conducts research and makes the rounds at Children's Hospital, where he runs the Center for Robotics Surgery, using a robot he calls "Fluffy," after the three-headed dog in the "Harry Potter" series, to perform complex yet less invasive surgeries.

When he isn't painting, he dances jazz and ballet.

In his spare time, the trained chef volunteers as a Big Brother. Always, though, he finds the time to connect with children.

One recent afternoon in Boston, he stood by the bed of a 5-year-old Plainville girl who had just undergone surgery. Her father stroked her hair. Her mother stood quietly nearby.

"Everything went really well," Nguyen said calmly to the parents, as their eyes clung to his every word.

After leaving the room, the doctor strode briskly through the wide hallways of Children's Hospital. He had performed four surgeries that morning, but there was no slowing down for Nguyen. He has a lot more work to do.