CTA CIRCLE OF WILLIS (updated 10/28/2020, last reviewed 10/28/2020)
INDICATION: Aneurysm, stenosis, occlusion, stroke, thromoembolism, dissection, vasculitis, vascular infection, preoperative planning, vasospasm, vascular tumor/malformation.
SERIES
1) Noncontrast head CT
2) CTA COW
- 1mm axial CTA
- 2mm coronal CTA
- 2mm sagittal CTA
- 3D
| | |
|
POSITIONING/MODE
|
supine/helical |
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kV/mA/rot time
|
120 kV/auto mA/<1 sec |
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DETECTOR COLLIMATION
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16 x 0.75mm (S16) 64 x 0.6mm (D64) |
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SLICE THICKNESS
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1mm |
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PITCH
|
</=1 |
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KERNAL
|
soft tissue |
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SFOV
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<30cm |
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COVERAGE
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foramen magnum -> vertex |
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ACQUISITION
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caudocranial |
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IV CONTRAST
|
80 mL Isovue 370 |
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INJECTION RATE
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4 mL/sec |
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SCAN DELAY
|
Bolus tracking @ aortic arch (~20 sec) |
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POSTPROCESSING
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Coronal, Sagittal, 3D |