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

Care kV (ref. kV 100)

Effective mAs

CareDose

Quality Reference mAs

123

Time (Rotation)

0.5 sec.

Average Acquisition Time

2-3 sec.

Collimation

128 x 0.6 mm

Pitch Value

1.2

Scan Direction

Caudocranial

Comments: Iso-centering the patient within the gantry is key to image quality. CareDose 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

Hv38 (3)

Hr60 (3)

Hv49 (3)

Hv38 (3)

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

Hv49 (3)

Hv49 (3)

Hv49 (3)

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.