In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: High - signal intensity lesions on DWI tended to show low signal intensity on ADC map ( 3 / 4 ) , but in one patient , high signal intensity was shown at bilateral dentate nuclei on not only DWI but also ADC map .
### Output Text:
High - signal intensity lesions on DWI tended to show low signal intensity on ADC map ( 3 / 4 ) , but in one patient , high signal intensity was shown at bilateral dentate nuclei on not only DWI but also ADC map . 