1 year post-op TT- I have nodules on upper stomach, not sure if it's scar tissue or dissolvable sutures. Should I get a ct scan?

There could be many reasons for such nodules.
First as you guessed, it could be an internal suture used to repair muscle. Such suture many a times is chosen non dissolvable for longevity of results.

Secondly, it could be a scar hardening due to delayed healing of the wound as you told wound healed after VAC.

Also some rare possibility of tissue growth.

For knowing what is the problem, an Ultrasound is helpful and probably enough. No need of CT scan directly. But the best diagnosis is made when the physician examines you in person. So i would suggest you to visit your treating physician first or any board certified plastic surgeon before going for any investigation.
Hope that i have cleared your doubt. Thank you for posting your query. Wishing a healthy life.

Dear lhcdeb,
I understand your concern. However, without a proper assessment, it would be difficult to determine what went wrong. It is best that you visit your plastic surgeon for further assessment or ask for a second opinion. Only after a thorough examination, you can get proper recommendations and advice.
Daniel Barrett, MD
Certified, American Board of Plastic Surgery
Member, American Society of Plastic Surgery
Member, American Society of Aesthetic Plastic Surgery

I encourage you to return to your surgeon for an evaluation. An exam is needed to determine the proper next steps to identify and address the nodules that concern you.

You should try to have your original surgeon reassess the area.
A physical exam would aid in diagnosis. It could be one of several conditions. A CT scan would be done if the physical exam cannot diagnose the issue.