Can a cat scan tell if you have hiv?

No: While there may be some findings on a ct scan that are more associated with HIV than in people without it, there is nothing definitive that a ct scan can diagnose about hiv. A blood test or mucosal swab can check for the virus itself.

Not really . . .: Hiv/aids is diagnosed via blood testing. Hiv is the infection whereas aids is the situation where your immune system is truly weakened. In that case, it's possible to become very suspicious of a diagnosis of HIV if ct scan picks up an opportunistic disease such as tumor or cysts in brain. But we'd still run blood tests looking for viral load etc before actually making diagnosis.

Yes, when advanced: There are no ct findings diagnostic of the HIV virus. The are certain infections and tumors that are commonly seen in patient with aids.