Italian to English Medical Medical (general)

Hello fellow translators!
I am translating a medical reports and toward the end, at the summary, I read this:
(context)
" REFERTI:
-EE (DATE): NELLA NORMA...
-TC t/a mdc (date): esiti chirurgici, negativo per ripresa della malattia. "
I know that it refers to a CT scan ( document in my possession where it shows that the exam was performed with and without contrast agent ). Do you know what "t/a" refers to? does it have to do with the concept of "with and without contrast agent"?
Thank you !!

Naomi H.