<prompt> Early stage of carcinoma esophagus is diagnosed byBarium mealTrans oesophageal USGMRIFluoroscopy  <response>: .investigations for carcinoma oesophagus includes 1barium swallow -shouldering sign and irregular filling defect.RAT TAIL defect in fluoroscopy is typical. 2oesophagoscopy -to know lesion, extent and types. 3biopsy -histological evaluation 4X-ray CTMRI bronchoscopychromoendoscopyoesophageal endosonography ref: SRB;s manual of surgery,5th ed, pg no 806 