"I like this," muttered Cuigniez, 55, clearly under the thrall of both the doctor and the artist - himself a Philadelphia native. "The brushstrokes, the layers."
When he is not X-raying people, Cuigniez X-rays paintings in Europe to help determine authenticity. After he examined an X-ray of The Gross Clinic that is part of the exhibition, Cuigniez nodded his head, satisfied.
"Oh, it's not counterfeit," he said, smiling.
Dramatically displayed under six spotlights in a dark gray gallery, the painting has benefited from the meticulous work of museum conservators. In essence, they fixed a botched restoration that had been done in the 1920s, like surgeons reversing a medical error.
In the original restoration, the canvas had been brightened in spots that the artist had wished to keep dark, which served to obscure faces and features that are now more easily seen, conservators said.
"It used to have a weird orange tint," said David Webber, 56, a South Philadelphia lawyer who was visiting the exhibition as part of his birthday celebration. He had seen the painting years before, when it was displayed at Thomas Jefferson University, which had owned the work.
"Now, I see what Eakins meant to show," Webber continued. "The orange is less bright now. It looks more dramatic, like it was painted yesterday."
Not long ago, Jefferson sought to sell the painting to two out-of-town museums. After a public campaign in 2006 led by the Art Museum and the Pennsylvania Academy of the Fine Arts, $68 million was raised to buy the work in 2007 and keep it in Philadelphia. In 2008, the first steps toward restoring the painting were begun by the museum and the academy, which now jointly own the work.
While art lovers gathered around the painting, Cuigniez stood his ground, continuing to mull the work.