Neuro

Circle of Willis: R/O aneurysm

Specific Anatomic Region

Circle of Willis

Application

R/O aneurysm

Author

Katz DA et al.

Reference Source

Radiology 1995; 195:445-449

Scanner Used

Siemens Somatom Plus-S

Injection Rate

3ml/sec

Contrast Volume and Type

90ml of Omnipaque-300

Area Scanned

Entire brain (if possible)

Scan Delay

Test-dose timing (usually 15-25sec)

Length of Spiral (time)

40sec

Slice Thickness

1mm

Table Speed/Pitch

1.3mm/sec with a pitch of 1.3

Reconstruction Interval

0.5mm

3D Technique Used

None used

Comment:

• 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.