 So let's walk through some unknown cases now. This is somebody that had a history of enterubitis in the past. Looking through their CT, we can see that there are multiple tiny nodules and masses within the lung parankumma. We can also see that there are some areas of architectural distortion with a little bit of traction bronchiectasis and bronchial wall thickening. And we see that the disease is fairly diffuse throughout the lung parankumma. So how do we characterize these nodules? So at first glance, you'd see that these nodules are solid and well-defined. So that can really be seen with either miliary peri-lymphatic or sensual obler. So it's not particularly helpful. Some of these nodules do appear to be sparing coral surfaces, like in this area and here. You may be wondering, are these tree and bud opacities? And that's totally reasonable. Based on this one area, I think I would have a really hard time knowing, am I looking at tree and bud opacities? But really the key thing with this case is to look for that fish role and plural involvement. And when we look at the fissures and coral surfaces here, notice that we look at this minor fissure. Look how many tiny dots are along this minor fissure. There's tiny dots all throughout the course of the minor fissure and extending off to the major fissure. That is not good for central lobular disease. It's not good for central lobular disease. So once you have involvement of the fissures, like in this case, that tells you that you're probably not looking at a finding that's predominantly central lobular. Now, could this person also have a little bit of a central lobular disease, like a small airway infection? That's possible, right? But when we see this, you know, all this fish role involvement, that really should point us more towards either a paralemphatic or a miliary process. Now, deciding between those two, again, we have to decide, do we think that that's more diffuse or more clustered? And in this case, again, it's kind of throughout the lung parankama, but if we focus on, say, like the right upper lobe, notice how some of these nodules are really just kind of in some areas, but there's areas that are appear largely spared. Now that we look closer at them, and we kind of zoom in to say this area in here, what we're actually seeing is a septa, and then we're seeing little tiny nodules studying along the septa, creating a line, right? And when we see lines of nodules, that should make us think of a paralemphatic process. So now we're seeing nodules along the fish role and coral surfaces. We're seeing lines of nodules, again, telling us that it's paralemphatic. And when we see that, our top two differential diagnoses, remember, should be sarcoidosis or paralemphatic disease related to lymphogenic carcinomatosis. We don't see a lot of smooth septal thickening now. The absence of smooth septal thickening should then lead us away from lymphogenic tumor and more towards sarcoid. In addition, we have this mass up here. So now is this mass related to a separate process like a lung cancer or is it related to sarcoid? I think based on just this image, it would be really hard to know the answer to that. You'd have to use comparison imaging to see if it was stable or if it was gradually enlarging over time. In this case, this nodule was actually stable for several years. Again, you could see larger confluent nodules in the setting of sarcoidosis. Remember, we saw that with the galaxy sign where we have little tiny nodules along the outer edges of it creating a more confluent nodule within the center. So this is actually a case of sarcoidosis producing a micro nodule that are lung disease. I think this case would have been a little bit challenging because you'd have been wondering if some of these nodules, like in this stuff out here, was related to central lobular disease like gene vettel pacity. And I think really the key feature in this case was the fact that there was studying of the fissural and pleural surfaces and the fact that the nodules were kind of clumped and forming lines within the lung peranthemum. Tying into the history of antler uveitis, antler uveitis you can see as a associated symptom of sarcoidosis.