Imaging 
• X-rays of the upper gastrointestinal tract (UGI series) by standard and double-contrast methods may find
  larger ulcer lesions.
• Chest x-rays.
• CT scan of the abdomen. 
• Bone scan if the bone enzyme alkaline phosphatase is elevated in the serum.
• Ultrasound to help measure tumor size and predict recurrence .

Endoscopy and Biopsy 
• Examination of the stomach through a gastroscope inserted through the esophagus (fiberoptic endoscopy) may
  find ulcers and masses. It is the most definitive test for diagnosing stomach cancer. Seventy percent of early
  malignant ulcers may look benign and even heal, but are usually positive on biopsy.
• A small piece of tissue may be removed from any suspicious area for biopsy analysis by a pathologist , or a
  brush can be passed through the gastroscope to obtain cells in a way similar to a Pap smear. Tissue and brush
  biopsies can diagnose 98 percent of cases.