I have CPTSD which began at age 2-3. I am now 59 and coming down from my last flare. I have had CT and MRI'S of my brain, which would rarely show anything at all. The MRI I think you and others here are referring to is a fMRI or functional MRI. What PTSD does to the brain and how long you have had it will determine how much the brain has changed it circuitry. When we experience trauma as a child our brain will change to help us to adapt to the trauma we could not talk about then. It allows us to function somewhat normally. I knew at age 3 that the sexual molestation was wrong and I stood in the middle of the street yelling "don't make me go" back to the neighbor who abused me. At ages 6, 9, and 11, I realized I was not like everyone else, that there was something wrong with me but I did not know what. That was in the 60's. I was not diagnosed until I was 23 and that 2as after another trauma (physical). Phyical, emotionally, spiritual and psychologically trauma all effect us, whether we realize it or not. You don't need an MRI to tell you that because only a FMRI is the only acceptable means to show the damage or change. There are numerous parts of the brain that work together and they all evolve over time. For the sake of worrying or wondering whether your brain has been changed the answer would be "yes." You can't do anything about it other then to learn to change it. I had been free from flares for a period of about 20 years. Until my life changed and it triggered my brain to react again. Mediation can help change your brain by bringing down the arousal and teaching you how to manage or regulate yourself. You need meds but for me, it takes about 5-6 months to get out of a flare (I have had 4 in the last 10 years). Utube has alot of free Meditations available.