Pablo Picasso's Guernica, depicting the Nazi German bombing of Guernica, is seen in Spain's Reina Sofia museum in Madrid on Tuesday. (Paul White/Associated Press)Guernica depicts intense suffering, but its own health is not in danger. That's the diagnosis after the first X-ray of Pablo Picasso's 20th-century anti-war opus carried out by the Reina Sofia art museum.

The X-ray of the large-format canvas — 3.5 by 7.8 metres — was part of a series of tests begun over a year ago on one of the world's most prized masterpieces.

Guernica's last major analysis a decade ago turned up 129 imperfections — ranging from cracks to creases to marks and stains — all attributed to the painting's hectic past.

"The X-ray lets us see in what condition the painting is in, its makeup, the colours and the damage it has suffered," Reina Sofia director Manuel Borja-Villel told the Associated Press in an interview this week.

"The good news is that the latest X-ray results show the imperfections haven't increased," said Borja-Villel. "But age pardons no one, and paintings are no different."

The studies now being pieced together by the museum's specialists aim to produce a definitive analysis of the painting by 2010. So far, tests show the painting needs only a periodical dusting and a possible cleanup of some stains resulting from its only previous restoration, done by New York's MOMA in 1957.

Guernica was commissioned from Picasso by the Republican government of Spain to represent the country at a Universal Exposition in Paris in 1937 as Spain writhed in a bloody civil war started by the future dictator Gen. Francisco Franco.

Once the fair was over, the painting went on the road for nearly 20 years, visiting dozens of cities on both sides of the Atlantic.

"Every time it was moved, it had to be taken off its support and rolled up. That took its toll over the years until one day at the beginning of the 1960s Picasso himself said, "Enough is enough,'" said Borja-Villel.

"The painting has a robust constitution but its travelling days are definitely over," he added.

The painting made its final trip when it was transferred to Spain in 1981 from MOMA, where it had been deposited on a long-term loan by Picasso until democracy was restored back home.

Represents horrors of mechanized war

The black-and-white canvas comprises tormented and distorted figures — human and animal — and represents the horrors of mechanized war.

Picasso, the father of modern art, was a world-renowned figure at the time and the work quickly became an artistic and political icon. It has since become one of the most studied works of art in modern history.

Guernica, the ancestral capital of northern Spain's Basque country, was bombed on a spring market day in April 26, 1937, by Germany and Italy. Those country's fascist rulers were Franco's allies in a civil war that set the stage for the Second World War.

Although estimates of the number of people killed in the bombing vary greatly, town historians say local records show at least 120 deaths.