[Unruptured intracranial aneurysms: evaluation with high-resolution MR angiography with magnetization transfer contrast (MTC) and tilted optimized nonsaturating excitation (TONE)].

Forty-one patients with suspected intracranial aneurysms were evaluated by conventional three-dimensional (3D) time-of-flight (TOF) MR angiography (MRA) or high-resolution 3D TOF MRA with magnetization transfer contrast (MTC) and tilted optimized nonsaturating excitation (TONE). Correlative study was done with conventional angiography in all patients. 3D TOF MRA detected 30 of 36 aneurysms depicted at conventional angiography. The overall rate of sensitivity for the detection of aneurysms was 83%. Unruptured aneurysms were unlikely to occur in the anterior communicating artery (3%), but were frequently found at the bifurcation of the middle cerebral artery (33%). Conventional MRA showed 7 of 9 aneurysms demonstrated at catheter angiography. The rate of sensitivity of conventional MRA for aneurysms smaller than 5 mm and greater than or equal to 5 mm were 0% and 100%, respectively. High resolution MRA with MTC and TONE demonstrated 23 of 27 aneurysms detected by catheter angiography. Sensitivities of high resolution MRA with MTC and TONE for aneurysms smaller than 5 mm and greater than or equal to 5 mm were 71% and 100%, respectively. Our results indicate that high-resolution 3D TOF MRA with MTC and TONE can provide precise, accurate depiction of intracranial aneurysms larger than or equal to 5 mm.