Acquisition Phase

Phase Included

Scan Delay

Respiration Phase

Anatomical Coverage

Non Contrast

Yes

N/A

N/A

Base of skull through vertex

Arterial Phase

 N/A

N/A

N/A

N/A

Venous Phase

 N/A

N/A

N/A

N/A

Delayed Phase

 N/A

N/A

N/A

N/A

Scan Comments: The F/U shunt protocol is performed using a low dose sequential scan to limit patient exposure. Isocentering and properly positioning the patient within the gantry is key to image quality and limiting the radiation dose. If the patient is unable to hold still for the duration of the exam, a low dose spiral study can be performed instead to decrease the scan time. All scans are performed using the ALARA principle.

 

Technical Parameters

Parameters

kVp

120

Effective mAs

CareDose

Care Dose Reference mAs

150

Time (Rotation)

1.0 sec (Full) / 3.0 sec cycle time

Average Acquisition Time

29 sec

Collimation

128 x 0.6mm

Table Feed

34.5mm

Scan Direction

Caudocranial

Comments: CareDose is used to limit patient exposure.

 

Reconstruction Parameters

Soft Tissue

Thin Data

Bone

Slice Thickness

5mm

0.75mm

5mm

Reconstruction Spacing

5mm

0.5mm

5mm

Reconstruction Algorithm

J30s

J30s

J70h

Window Width and Level

100/30

100/30

2500/500

Reconstruction Comments:  True axial MPR images are generated when patients are unable to be positioned correctly.

 

Contrast Parameters

Parameters

Contrast Type

 N/A

Contrast Volume

 N/A

Saline Flush

 N/A

Injection Rate

 N/A

Oral Contrast

 N/A

Contrast Volume

 N/A

Comments: IV contrast is not typically necessary for this exam.