1794
BACKGROUND : No direct comparisons exist of the renal tolerability of the low - osmolality contrast medium iopamidol with that of the iso - osmolality contrast medium iodixanol in high - risk patients .
 Chemical: contrast medium; Chemical: iopamidol; Chemical: contrast medium; Chemical: iodixanol
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Disease, Chemical 
Text: {0} 
 Entities: contrast medium, iopamidol, contrast medium, iodixanol 
Answer:
 Chemical: contrast medium; Chemical: iopamidol; Chemical: contrast medium; Chemical: iodixanol