"Patent" means the vein is open and has good flow.

From the limited context this patient has a normal ultrasound, so we wouldn't expect the Spanish "permeable" to mean "permeable" in the English sense of the word, in which too much fluid is getting through the vessel walls, causing an excess of interstitial fluid and edema. You wouldn't see vessel permeability itself on an ultrasound. You would, however, see edema, which this patient does not seem to have.

In Spanish "porta permeable" is a normal and good thing. In English, it's not, so I would consider these terms almost false friends.

Interestingly, French does the same thing as Spanish: https://forum.wordreference.com/threads/the-veins-are-patent...