Congress President Sonia Gandhi, who is recovering from chest infection at a city hospital in New Delhi, underwent a CAT scan today and her condition is stated to be "steadily improving"."CAT scan of Gandhi's chest has been done on Thursday and it is normal," said B K Rao, chairman of Sir Gangaram Hospital, where the 61-year-old leader was admitted on January 1.Gandhi's condition is steadily improving and she has been advised to continue rest, he said.He said Gandhi had normal food and comfortable sleep last night.However, the hospital did not specify when the UPA Chairperson was expected to be discharged.Gandhi was admitted in the hospital in the early hours of New Year's Day after she complained of difficulty in breathing.