 This was a seven-month-old child who presented with otomastoiditis on the right side. If we look at the brain images, we see that the patient has somewhat large vessels for age. And as we continue down inferiorly, we see the inflammation at his present superficial to the upper portion of the mastoid region. Here in the mastoid region, basically we see bilateral opacification on T2-wayed scan of the mastoid air cells. And on the right side, you also see the external auditory canal, which is opacified. On the post-gadolinium enhanced scan, you get a sense that the patient has meningeal enhancement in the posterior fossa, which is rather striking. And where one would expect to see the sigmoid sinus and distal transverse sinus, instead we see enhancing tissue. Here's the flow void on the left side, which is normal. On the right side, you have this opacification with enhancing matted tissue. And even as we go down into the sigmoid sinus region here, here's the normal sigmoid sinus leading into the jugular vein. I want to point this out only right side with my magic pen. What you're seeing is enhancement in the wall of the sigmoid sinus going into the jugular vein. But within the jugular vein, we're seeing low signal-intensity tissue and the sigmoid sinus as well. And this represents the thrombus, which is going from sigmoid sinus into the jugular vein at the skull base. If we continue to scroll down, we can see the jugular vein absence of a flow void. Here's the normal jugular vein and internal carotid artery. Here's the internal carotid artery and the jugular vein. And there is enhancing tissue within the carotid sheath on the right side associated with the thrombus vessel. So this is thrombophlebitis of the right internal jugular vein, secondary to odomastoiditis. Let me just point out anatomically the structures that we sometimes will refer to in the carotid sheath. And that is the overlying musculature. So this darker signal-intensity superficial to the carotid artery is the styloid musculature, which defines the post-styloid paraphernalia space, the carotid space from the pre-styloid paraphernalia space which has the fat within it. And this is part of this tissue here besides the inflammation is that same musculature, the styroglossus, the styloforengius, and the stylohyoid muscles. Let's just quickly look at the sagittal image because it will nicely demonstrate the inflamed jugular vein. This is the normal jugular, normal sigmoid sinus in jugular vein on the left side, on the right side. You have all this thickened tissue from the odomastoiditis and you have the clot within the sigmoid sinus going into the jugular vein braille.