<prompt> An old man presented with fever and abdominal pain. Diveiculitis is suspected. If it is Meckels diveiculum is involved, it can be best diagnosed by:X-rayUltrasoundCT ScanTc99 peechnetium scan  <response>: Diagnosis of Meckel diveiculum is made with a Meckel scan. Technetium-99 99mTc-peechnetate is taken up by the heterotopic gastric mucosa in the diveiculum and outlines the diveiculum on a nuclear scan. Giving pentagastrin or cimetidine before administering the radionuclide increases 99mTc-peechnetate uptake and retention by the heterotopic gastric mucosa and can increase the sensitivity of the test. The sensitivity of CT scanning for the detection of Meckels diveicula is too low to be clinically useful. Ref: Sundaram S.S., Hoffenberg E.J., Kramer R.E., Sondheimer J.M., Furuta G.T. 2012. Chapter 21. Gastrointestinal Tract. In W.W. Hay, Jr., M.J. Levin, R.R. Deterding, J.J. Ross, J.M. Sondheimer Eds, CURRENT Diagnosis Treatment: Pediatrics, 21e. 