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/AN/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

Semi (ref. kV 120)

Effective mAs

CareDose

Quality Reference mAs

320

Time (Rotation)

1.0 sec.

Average Acquisition Time

3-4 sec.

Collimation

64 x 0.6 mm

Pitch Value

1.0

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)

Bone (B)

Thin Data (R)

Slice Thickness

0.4 mm

0.4 mm

0.4 mm

0.4 mm

Reconstruction Spacing

0.2 mm

0.2 mm

 0.2 mm

0.2 mm

Reconstruction Algorithm

Uh36 (3)

Ur77 (1)

Ur89 (1)

Ur77 (1)

Window Width and Level

350/50

2500/500

2500/500

2500/500

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. Special orthogonal, plane, and radial MPR images are performed in these cases.

 

Reconstruction Parameters

Thin Data (R)

Thin Data (L)

Thin Data (L)

Slice Thickness

0.4 mm

0.4 mm

0.4 mm

Reconstruction Spacing

0.2 mm

0.2 mm

0.2 mm

Reconstruction Algorithm

Uh36 (3)

Ur77 (1)

Uh36 (3)

Window Width and Level

350/50

2500/500

350/50

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. Special orthogonal, plane, and radial MPR images are performed in these cases.

 

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.