Correlation of 3D TOF MRA with DSA in the Detection of Intracranial Aneurysms

Purpose Our goal was to determine the accuracy of MR angiography for the diagnosis of intracranial aneurysms and factors that decreased its accuracy. Methods We retrospectively studied 30 patients, among them 20 with acute subarachnoid hemorrhage. 3D TOF MRA and DSA were typically performed in 30 patients. Conventional spin echo MR images and MR angiograms were reviewed together, and the results were compared with those obtained at intraarterial DSA to determine the sensitivity of MR angiography. Results All of 30 aneurysms were identified at intraarterial DSA. 25 aneurysms(1 false) were depicted and 6 aneurysms were missed by MR angiography. Sensitivity and false positive of MR angiography for detecting intracranial aneurysms were 80% and 4% respectively. Most of missed aneurysms were located at C1 2 segment on the carotid siphon or near the beginning of the posterior communicating artery. Conclusion Three dimensional time of flight MR angiography is one of sensitive methods to identify intracranial aneurysms. Size of the aneurysm and hemorrhage near the aneurysm can affect depiction of aneurysms, and the position of intracranial aneurysms may also affect their display. [