This is Dr. David
no, a CT scan is not good enough.
if you are postmenopausal and have uterine thickening you need a urine biopsy
are you having postmenopausal bleeding?
have you had a transvaginal ultrasound? that might be able to find the cervical os.
also vaginal estrogen cream over a bit of time can help with vaginal atrophy and help the doctors be able to find the cervical os for a uterine biopsy
a pelvic MRI scan would be better than a CT scan as well.
let me know if you have questions.