Anatomy of Carotid Artery

Image taken from Radiopaedia.org

Appearance of Carotid Artery in CT VRT Image

VRT Image of Carotid Artery

Protocol Structure

00_CarotidAngioRoutine (Adult)

  • Topogram (AP)
  • Premonitoring
  • Monitoring
  • Contrast (Carotid Angio)

Patient Orientation Registry in System

  • Set the orientation patient in system : Head First – Supine

Topogram

  • Position the patient in head first supine position.
  • Placed the patient’s head inside the head holder and properly strap the head and chin.
  • Align the patient in Mid-Sagittal plane of the table.
  • Position the transverse laser light beam above glabella to start the topogram.
Topogram Lateral of CTA Carotid

Topogram Parameters

Topogram (AP)

  • Topogram length: 512 cm
  • Slice: 0.6 mm
  • Scanning direction: Craniocoudal
  • Tube position: Top
  • Stop the topogram scanning when the scanning reach / pass over the arch of aorta

Topogram (Lateral)

  • Topogram length: 256 cm
  • Slice: 0.6 mm
  • Scanning direction: Craniocoudal
  • Tube position: Lateral
  • Stop the topogram scanning when the scanning reach / pass over the base of skull

Pre-Monitoring / Contrast Trigger

  • Activate the topogram image.
  • Place the scan planning line at the level of aortic arch.

Scanning Parameters

  • kVp: 120
  • mAs: 20
  • Scanning Direction: Caudocranial
  • Scan Delay: 2 s
  • Slice: 10.0 mm
  • Image Comment: –
  • Pitch: –

 

Contrast

Type of contrast used:

  • Non-ionic iodinated contrast media
  • Preferrable: 370 I mg/mol 

 

Needle Placement Test:

  • Flow Rate: 5.5 ml/sec
  • Volume of Normal Saline: 40 ml

 

Contrast Injection:

  • Volume of Contrast Media: 50 ml 
  • Volume of Normal Saline: 50 ml
  • Method of injection: Contrast Injector
  • Flow Rate:
    • Contrast: 5.0 ml/sec
    • Normal Saline: 5.0 ml/sec

Post Contrast Scan Planning

Monitoring

  • Single click on the pre-monitoring image
  • Single click again to activate purple circle for triggering
  • Drag and drop the circle inside the aortic arch region
  • Click TRIGGERING tab
  • Set the Hounsfield Unit value to 80

Setting the ROI circle for triggering

Contrast triggering start

Contrast HU reached the trigger value

Scanning Parameters

  • kVp: 120
  • mAs: 20
  • Scanning Direction: Caudocranial
  • Scan Delay: 2 s
  • Slice: 10.0 mm
  • Image Comment: –
  • Pitch: –

 

Contrast (Carotid Angio)

Scanning Parameters

  • kVp: 80
  • mAs: Effective mAs
  • Scanning Direction: Caudocranial
  • Scan Delay: 2 s
  • Slice: 4.0 mm
  • Image Comment: –
  • Pitch: –
  • Gantry Angulation: ZERO (No Angulation)

 

Reconstruction of CTA Carotid

Recon 1Recon 2
NameCarotidAngio 5.0 B30fCarotidAngio 0.6 B26f
Slice Thickness5.0 mm0.6 mm
Increment5.0 mm0.4 mm
KernelB30f medium smoothB26f medium smooth
WindowingLarynxCT Angio

Multiplanar Reconstruction (MPR)

N/A

Siemens SyngoVia 3D Rendering

Series of Images Send to PACS

  1. Topogram
  2. CarotidAngio 5.0 B30f
  3. CarotidAngio 0.6 B26f
  4. Patient Protocol
  5. VRT Radial Ranges CTA Carotid