CT Scans Reproduce Famous Stradivarius Violin

November 29, 2011

CHICAGO - By using CT scans and advanced manufacturing technology, experts recreated a 1704 Stradivarius violin - an instrument known for its high tonal qualities that fetched nearly $16 million at auction in June. Researchers presented the replica of the famous violin at RSNA Monday.

CHICAGO - By using CT scans and advanced manufacturing technology, experts recreated a 1704 Stradivarius violin - an instrument known for its high tonal qualities that fetched nearly $16 million at auction in June. Researchers presented the replica of the famous violin at RSNA Monday.

"We have two goals: to understand how the violin works and to make reproductions of the world's most prized violins available for young musicians who can't afford an original," said Steven Sirr, MD, a radiologist at FirstLight Medical Systems in Mora, Minn.

Italian Antonio Stradivari is known as history’s greatest violinmaker. Of the estimated 1,000 he made, only about 700 still exist. Theories behind what makes his violins superior to others are hotly debated.

Sirr worked with professional violinmakers John Waddle and Steve Rossow to recreate Stradivari’s highest quality model, the Betts.

"CT scanning offers a unique method of noninvasively imaging a historical object," Sirr said. "Combined with computer-aided machinery, it also offers us the opportunity to create a reproduction with a high degree of accuracy."

They scanned the original violin with a 64-detector CT, creating more than 1,000 CT images that were converted into stereolithographic files. A CNC machine, made by Rossow, used the files to carve the component parts of the violin from spruce, maple, ebony and willow woods.

They provided nearly exact copies, within 1/15000 of an inch of accuracy said Sirr, whose CT scan of a violin was done out of curiosity.

"I assumed the instrument was merely a wooden shell surrounding air," said the amateur violinist. "I was totally wrong. There was a lot of anatomy inside the violin."

After sharing the first CT images with Waddle, Sirr spent two years scanning more than 100 violins and other string instruments to better understand their composition.

"Just like human beings, there is a wide range of normal variation among violins," Sirr said.

Stradivarius violins are highly prized and often never played. The Betts Stradivarius violin is currently housed at the Library of Congress, where it’s kept under tight temperature and humidity controls and played occasionally by the world’s top violinists.

For owners of original Stradivarius or other valuable violins, CT scans would not only confirm their authenticity, but could also increase the investment’s value.

"CT is useful in measuring wood density, size and shapes, thickness graduation and volume measurements," Sirr said. "It also provides detailed analysis of damage and repair."

Although the researchers declined to comment on the prospective cost of the replica violin, they said it would be less than the several millions Stradivarius violins are currently sold for.

"We believe this process of recreating old and valuable stringed instruments may have a profound influence upon modern string musicians," Sirr said.

After playing the replica alongside the original, the researchers say the resemblance in sound quality is remarkable. They have started copying the successful prototype and have applied for a patent.