[Can multislice helical computed tomography replace conventional angiography in the diagnosis of non traumatic subarachnoid hemorrhage?].

AIM OF THE STUDY

To evaluate the reliability of CT angiography in the diagnosis of non traumatic subarachnoid hemorrhage.

MATERIALS AND METHODS

We prospectively studied 57 patients presenting with non traumatic subarachnoid hemorrhage. In all cases, CT angiography of the circle of Willis was performed, followed by conventional angiography. We compared the results of both techniques, with conventional angiography considered as the gold standard.

RESULTS

The specificity of CT angiography for diagnosing intracranial aneurysms was 100% with sensitivity and negative predictive values of 86% and 65% respectively. The aneurysms that were not diagnosed on CT angiography were located on the supra-cavernous internal carotid artery and their size was less than 5mm. Futhermore CT angiography failed to diagnose the other causes of subarachnoid hemorrhage.

CONCLUSION

CT angiography can be considered as a first line imaging technique for diagnosis of non traumatic subarachnoid hemorrhage. However, conventional angiography including three dimensional acquisitions must be performed for all cases where the cause of hemorrhage remains undiagnosed at CT angiography.