What does a three phase CT scan diagnose?

A three phase CT scan is a ct scan, usually of the liver, that requires an injection of contrast medium, this injection helps outline the vessels of your body by giving the x-rays something to be absorbed by besides blood which has a very low absorption rate. The phases are:

1. Scan during injection: arterial phase, this will highlight lesions in or around the artery leading into the liver.

2. Scan during injection or shortly after: portal vein phase, this will show lesions in or around the portal vein.

3. Delayed scan after injection: this will allow the soft tissue to absorb the contrast and may highlight changes in tissue.