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. We typically perform these studies using single energy because the acquisition speed is slightly faster allowing for less likelihood of venous contamination to occur. All scans are performed using the ALARA principle. 3D post-processing is performed with this protocol.

Technical Parameters

Parameters

kVp

120

Effective mAs

Use dose reduction software

Care Dose Reference mAs

300

Time (Rotation)

0.5 sec

Average Acquisition Time

2-3 sec

Collimation

128 x 0.6mm

Pitch Value

0.8

Scan Direction

Caudocranial

Comments: Iso-centering the patient within the gantry is key to image quality. Dose reduction software is used to reduce patient dose.

Reconstruction Parameters

Soft Tissue

Bone

Hi Res

Thin Data COW Mag

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

H30f

H60f

H50f

H20f

Window Width and Level

350/50

2500/500

700/80

350/50

Reconstruction Comments: Additional radial VRT images are also performed.

Reconstruction Parameters

Sliding MIP True Axial

Sliding MIP Coronal

Sliding MIP Sagittal

Slice Thickness

16 mm

16 mm

16 mm

Reconstruction Spacing

 3 mm

3 mm

3 mm

Reconstruction Algorithm

B50f

B50f

B50f

Window Width and Level

700/80

700/80

700/80

Reconstruction Comments: Additional radial VRT images 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.