An old man presented with fever and abdominal pain. Diveiculitis is suspected. If it is Meckel's diveiculum is involved, it can be best diagnosed by:

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 Meckel's 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.