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

Inspiration

Lung apices through the entire aortic vasculature

Venous Phase

N/A

N/A

N/A

N/A

Delayed Phase

N/A

N/A

N/A

N/A

Scan Comments: The Flash Spiral Aorta protocol is useful when aortic root pathology is a concern to eliminate cardiac motion. Additionally, the fast scan times are important when the patient is short of breath or a limited volume of contrast is needed. Noncontrast and delayed images may be necessary when following up stent placement or to r/o endovascular leak. Alternatively, dual energy can be used to provide a virtualnoncontrast images.  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

200

Time (Rotation)

0.28 sec

Average Acquisition Time

2-3 sec

Collimation

128 x 0.6mm

Pitch Value

2.0

Scan Direction

Craniocaudal

Comments: CareDose is used to reduce patient dose. We prefer to keep the pitch lower (less than 2.5) when scanning through the abdomen. This will avoid increased image noise or spiral artifact while still minimizing both cardiac and breathing motion.  

 

Reconstruction Parameters

Soft Tissue

Thin Data

Lung

Slice Thickness

 3mm

 0.75mm

 3mm

Reconstruction Spacing

 3mm

 0.5mm

 3mm

Reconstruction Algorithm

 I40f

  I26f / B20f

 I70f

Window Width and Level

 410/10

410/10

 1600/-500

Reconstruction Comments: When using Flash spiral mode the DFOV is limited by the smaller of the two detector arrays to 33.2cm. This limitation can be overcame by reducing the pitch value to allow for a greater DFOV. Coronal and sagittal image reconstructions are also performed.

 

Contrast Parameters

Parameters

Contrast Type

Non ionic

Contrast Volume

80-120ml

Saline Flush

N/A

Injection Rate

4-5ml/sec

Oral Contrast

H2O

Contrast Volume

1000ml

Comments: Bolus tracking is performed off the abdominal aorta using a 230 HU trigger setting.