When a negative x-ray gives no positive answer.
D000368:Aged; D019411:Clinical Laboratory Techniques; D003937:Diagnosis, Differential; D005260:Female; D005264:Femoral Fractures / Q000000981:diagnostic imaging; D005705:Gallbladder Diseases / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D010808:Physical Examination; D011859:Radiography; D013274:Stomach Neoplasms / Q000000981:diagnostic imaging