1201
The perfusion defect produced in 16 open chest dogs was compared with the anatomic area at risk measured by the postmortem dual - perfusion technique and with thallium - 201 single - photon emission tomography ( SPECT ) .
 Chemical: thallium
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 Chemical: thallium