The Grand Tour host was admitted to hospital during his holiday in Majorca and will be there for at least a week but has remained in good spirits - joking yesterday that he needed a fresh lung.
The scan shows fluid on the presenter's left lung
He will be in hospital for a week but could take six to eight more to make a full recovery.
He said he spent five days of his holiday in Majorca in bed before a doctor sent him for an X-ray and added: “I was admitted immediately. I’m running low on pants now.”
Thanking fans for get-well messages, the 57-year-old wrote online: “It’s really, really annoying because I’ve never had one day off work since I started in 1978.”
Accident-prone co-star Richard Hammond responded: “Wow. I didn’t know he had a job”. Clarkson joked that James May, who makes up the presenting trio, was now the only functioning member of the team, adding: “God help us.”