Gastroscopy for gastric ulcer.
D001706:Biopsy; D005753:Gastric Mucosa / Q000166:cytology; D005773:Gastroscopy / Q000706:statistics & numerical data; D006801:Humans; D010781:Photography; D011859:Radiography; D013274:Stomach Neoplasms / Q000175:diagnosis; D013276:Stomach Ulcer / Q000175:diagnosis* / Q000000981:diagnostic imaging