Sir I m 25 yrs old, I m having clubbing from last 6 yrs it progressed to stage 5 sometimes I had localized pinpoint pricking pain in right 5 the intercostal space, I had regurgitation problem earlier now it relieved no other complaints I consulted doctor earlier he said it can be idiopathic I got my x ray done 3 yrs back it was normal, CBP normal normal what is the best investigation to detect asymptomatic clubbing please answer as early as possible sir / Mam, thank you.