Acquisition Phase

Phase Included

Scan Delay

Respiration Phase

Anatomical Coverage

Non Contrast

Yes

N/A

N/A

Mastoid air cells through petrous ridges

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: Careful positioning is important to avoid unnecessary exposure to the eyes. Iso-centering the patient within the gantry is key to image quality. All scans are performed using the ALARA principle.

 

Technical Parameters

Parameters

kVp

120

Effective mAs

CareDose

Quality Reference mAs

280

Time (Rotation)

1.0 sec

Average Acquisition Time

16-18 sec

Collimation

16 x 0.3mm

Pitch Value

0.6

Scan Direction

Caudocranial

Comments: CareDose is used to reduce patient dose. Scans times are significantly longer than routine scans due to a small collimator size coupled with a low pitch value to increase resolution.

 

Reconstruction Parameters

Soft Tissue (B)

Bone (B)

Thin Data (R)

Thin Data (L)

Slice Thickness

2 mm

0.4 mm

0.4 mm

0.4 mm

Reconstruction Spacing

2 mm

0.2 mm

0.2 mm

0.2 mm

Reconstruction Algorithm

U30u

U70u

U70u

U70u

Window Width and Level

350/20

3500/500

3500/500

3500/500

Reconstruction Comments: Decreasing the display field of view for both the right and the left temporal bones will increase spatial resolution. Reconstructions are done both bilaterally and coned down for each temporal bone.

 

Reconstruction Parameters

Coronal (B)

Coronal (R)

Coronal (L)

Slice Thickness

1 mm

1 mm

1 mm

Reconstruction Spacing

1 mm

1 mm

1 mm

Reconstruction Algorithm

U70u

U70u

U70u

Window Width and Level

3500/500

3500/500

3500/500

Reconstruction Comments: Decreasing the display field of view for both the right and the left temporal bones will increase spatial resolution. Reconstructions are done both bilaterally and coned down for each temporal bone.

 

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.