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. A 3D Post Processing is performed with this protocol.

 

Technical Parameters

Parameters

kVp

120

Effective mAs

CareDose

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: Isocentering the patient within the gantry is key to image quality. CareDose is used to reduce patient dose.

 

Reconstruction Parameters

Soft Tissue

Thin Data

Bone

Slice Thickness

 3mm

 0.75mm

 3mm

Reconstruction Spacing

 3mm

 0.5mm

 3mm

Reconstruction Algorithm

 H30f

 H20f

 H60f

Window Width and Level

 350/50

 350/50

 2500/500

Reconstruction Comments: Axial, coronal, and sagittal sliding MIP image reconstructions are also performed. Additional radial VRT images are also performed.

 

Contrast Parameters

Parameters

Contrast Type

Non ionic

Contrast Volume

80-100mL

Saline Flush

N/A

Injection Rate

5-6mL/sec

Oral Contrast

N/A

Contrast Volume

N/A

Comments: Bolus tracking is performed off the aortic arch using a 25 HU trigger setting.