CT & CCTA on same day

Our physicians are doing a CT of the Chest and a CCTA on the same day (separate reports). Are these codes allowed if the CT of the Chest is for the interpretation of the non-cardiac findings, with a -59 modifier? Or is the CCTA inclusive of the CT Chest. Do we need 2 orders from the ordering physician? Can anyone refer me to documentation to support the correct coding of these codes?

Thank you

Ccta

http://www.imagingbiz.com/articles/view/the-ccta-playbook-a-guide-to-coding-reimbursement-and-operations/
Check your CCI edits for inclusive procedures. Coronary CT angiography (CCTA) includes a complete evaluation of the lungs and chest.
2010:
http://www.acr.org/Hidden/Economics/FeaturedCategories/Pubs/coding_source/archives/SeptOct09/2010CPTCodeUpdate.aspx

Thanks

thanks so much for the answer.