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| T1 pre-gad | T1 post-gad | T2 |
Diagnosis: Bifrontal hemorrhage probably due to trauma
The bifrontal location of this hematoma is a good appearance for rupture of an anterior communicator aneurysm. The angiogram in this patient, however, was negative. This does not rule out the presence of an underlying aneurysm. In patients with non-traumatic subarachnoid hemorrhage, 15% will have a negative angiogram. These patients may be divided in to 2 types. The first category consists of those patients who have hemorrhage localized to the prepontine region and ambient cisterns. These patients have almost always have a negative angiogram and are felt to have rupture of small perimesencephalic veins as a cause for their subarachnoid hemorrhage. The other category of patients consists of those who have a pattern of subarachnoid hemorrhage which is more compatible with an aneurysm rupture, such as blood in the sylvian fissures or the interhemispheric fissures. In these patients, follow-up angiography demonstrates an aneurysm in up to 20% of cases. In this particular patient, the combination of a negative angiogram plus the history of possible trauma with the subdural fluid collection over the right hemisphere makes the diagnosis of hematoma secondary to trauma more likely. Although underlying aneurysm is still possible. Related Cases Rinkel GJE, Wijdicks EFM, Hasan D, et al. Nonaneurysmal perimesencephalic subarachnoid hemorrhage: CT and MR patterns that differ from aneurysmal rupture. AJNR, 1991; 12:829-834.
Rinkle GJE, Wijdicks EFM, Hasan D, et al. Outcome in patients with subarachnoid hemorrhage on computed tomography. Lancet, 1991; 338:964-968.
Farres MT, Ferraz-Leite H, Schindler E, et al. Spontaneous subarachnoid hemorrhage with negative angiography: CT findings. J Comput Assist Tomogr, 1992; 16:534-537.
