Abstract
The authors reported 8 cases of intracranial aneurysms in which CT had on important role in the diagnostic process.
In 2 cases with subarachnoid hemorrhage (SAH), the first angiographic studies showed no aneurysm, but the use of CT revealed aneurysm itself and hemorrhage. By repeated angiography, aneurysm was found.
In other 2 cases with SAH, episodes of the symptom were atypical, and the diagnosis was obscure, but CT again revealed the aneurysm itself.
The other 4 cases had no episodes of SAH. With CT, three of them were found incidentally to have aneurysms, and the last case with the chiasmal syndrome already present, was found to have a huge aneurysm of the internal carotid artery of which shape and size were incompletely revealed in the angiogram. As for these non-ruptured aneurysms CT was considered helpful for preventive treatment.
On the basis of our experiences with these 8 cases, the following were considered necessary for detecting the aneurysm by CT.
1) Improvement of enhancement method, namely, the volume of contrast medium and the timing of scanning after injection of contrast medium.
2) Choice of the plane including the circle of Willis and immobilization of the head of the patient during scanning.
3) Differentiation from irrelevant images.
Concerning the last, some beneficial results might be obtained by using the subtraction method.
