Acquisition Phase

Phase Included

Scan Delay

Respiration Phase

Anatomical Coverage

Non Contrast

N/A

N/A

N/A

N/A

Arterial Phase

Yes

Bolus triggered

N/A

Base of skull through vertex

Venous Phase

N/A

N/A

N/A

N/A

Delayed Phase

N/A

N/A

N/A

N/A

Scan Comments: Non-contrast images are performed when indicated prior to CTA. Using a dual energy protocol is useful if bone removal is warranted. All scans are performed using the ALARA principle. 3D post-processing is performed with this protocol.

 

Technical Parameters

Parameters

kVp

100 / 140

Effective mAs

CareDose

Care Dose Reference mAs

270 / 270

Time (Rotation)

0.28 sec

Average Acquisition Time

3-4 sec

Collimation

128 x 0.6mm

Pitch Value

0.7

Scan Direction

Caudocranial

Comments: Images are acquired using 100/140 kVp setting with a Sn filter. CareDose is used to reduce patient dose. A 0.28 rotation time is used to increase scan speed to avoid venous contamination.

 

Reconstruction Parameters

Soft Tissue Open Field

Bone Open Field

Thin Data Open Field

Hi Res Brain Only

Slice Thickness

3 mm

3 mm

 0.75 mm

0.75 mm

Reconstruction Spacing

 3 mm

3 mm

 0.5 mm

0.5 mm

Reconstruction Algorithm

D30f

B70f

Q30f

B50f

Window Width and Level

350/50

2500/500

350/50

700/80

Reconstruction Comments: When generating mixed images, the DE composition is set to 0.8. MIP 360 degree spin and MIP 360 degree tumble reconstructions are also performed.

 

Reconstruction Parameters

Thin Data COW Mag

Sliding MIP True Axial (Brain Only)

Sliding MIP Coronal (Brain Only Aligned to Basilar Artery)

Sliding MIP Sagittal (Brain Only)

Slice Thickness

0.75 mm

16 mm

16 mm

16 mm

Reconstruction Spacing

0.5 mm

3 mm

3 mm

3 mm

Reconstruction Algorithm

I26f

B50f

B50f

B50f

Window Width and Level

350/50

700/80

700/80

700/80

Reconstruction Comments: When generating mixed images, the DE composition is set to 0.8. MIP 360 degree spin and MIP 360 degree tumble reconstructions are also performed.

 

Contrast Parameters

Parameters

Contrast Type

Non-ionic

Contrast Volume

50 mL

Saline Flush

N/A

Injection Rate

5-6 mL/sec

Oral Contrast

N/A

Contrast Volume

N/A

Comments: Bolus tracking is performed off the carotid arteries.