Specific Anatomic RegionCircle of Willis
ApplicationR/O aneurysm
AuthorKatz DA et al.
Reference SourceRadiology 1995; 195:445-449
Scanner UsedSiemens Somatom Plus-S
Injection Rate3ml/sec
Contrast Volume and Type90ml of Omnipaque-300
Area ScannedEntire brain (if possible)
Scan DelayTest-dose timing (usually 15-25sec)
Length of Spiral (time)40sec
Slice Thickness1mm
Table Speed/Pitch1.3mm/sec with a pitch of 1.3
Reconstruction Interval0.5mm
3D Technique UsedNone used
  • Spiral compared favorably with MRI. We like to use 3D imaging with volume rendering when looking at the aneurysm and its vascular anatomy. By using fly-around virtual techniques the neck of the aneurysm is best seen.
  • Preset delays of 20 sec work well in these cases.