CT scanning used to recreate Stradivarius violin

Using computed tomography (CT) imaging and advanced manufacturing techniques, a team of radiologists and violin makers has created a reproduction of a 1704 Stradivarius.

Italian Antonio Stradivari, who lived from 1644 to 1737, is regarded as history’s greatest violin maker.

Of the 1,000-odd violins he made, around 650 still exist and are highly prized for their unique sound quality. Nobody knows why they’re quite so good, but factors affecting the sound of a violin include its shape, degree of arching and wood thickness.

“CT scanning offers a unique method of noninvasively imaging a historical object,” says Steven Sirr, a radiologist at FirstLight Medical Systems.

“Combined with computer-aided machinery, it also offers us the opportunity to create a reproduction with a high degree of accuracy.”

Sirr worked with professional violin makers John Waddle and Steve Rossow of St. Paul, Minnesota, to create an instrument based on the results of the scan.

“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,” says Sirr.

The original violin was scanned with a 64-detector CT, and more than 1,000 CT images were converted into stereolithographic files, which can be read by a computer-controlled router called a CNC machine.

The CNC machine, custom-made for the project, then carved the back and front plates and scroll of the violin from various woods. Finally, Waddle and Rossow finished, assembled and varnished the replica by hand.

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

Sirr and Waddle have spent years scanning more than 100 violins —including 29 valuable instruments pre-dating 1827 — and other stringed instruments to better understand their composition.

“Just like human beings, there is a wide range of normal variation among violins,” says Sirr. “When you are looking at an instrument that is hundreds of years old, you will see worm holes and cracks that have been repaired, as well as damage from being exposed to all kinds of conditions, from floods to wars.”