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Gated CTA CAP

Last Updated: 2026-01-01 Author:

  • 1. Clinical Summary

    Series Phase Coverage
    Flash Non-contrast Non-contrast Thoracic inlet to Pubic symphysis
    Gated CTA Chest Arterial (bolus tracked) Thoracic inlet to Diaphragm
    Flash CTA AP Contrast (Immediate after chest delay) Diaphragm to Pubic symphysis
    Stent delay (optional) Contrast (40 sec delay) Stent coverage
    • Aortic dissection
    • Aortic aneurysm with cardiac involvement
    • Combined cardiac and aortic pathology

  • 2. Patient Prep

    • Position: Supine with arms raised
    • NPO Status: NPO 2-4 hours
    • Pre-Medication:
      • HR < 65 target. Premedication not required.

  • 3. IV Contrast & Injection

    Parameter Value
    Agent Isovue 370
    Volume 1.6 mL/kg
    Flow Rate 4 mL/s
    Duration 20-24s
    Timing Method Bolus Tracking
    ROI Placement Ascending aorta
    Trigger (HU) 180 HU

    Use full dose if GFR > 30

    If GFR < 30

    Max Contrast = \(2*\left[\frac{\text{Patient Weight}}{75 \text{ kg}} * \text{eGFR}\right]\)

  • 4. Special Notes

    • TWO acquisitions: 1) Gated retrospective CHEST 2) Flash helical ABDOMEN/PELVIS. Chest gated for aortic root. AP flash arterial
    • Additional Recons: Curved MPR full aorta. Aortic valve reformats. 3D VR
    • 20G IV minimum

    Safety First

    • Renal Function: Verify eGFR > 30
    • Allergy: Check allergy history
    • Gated chest: assess aortic root valve coronaries. Flash AP: assess aorta and branches. Combined cardiac and vascular
    • Arms up. Careful timing between gated and flash acquisitions
Series Name Start Location End Location Delay Slice Thickness Notes
Scout Thoracic inlet Pubic symphysis N/A N/A Full AP lateral
Flash Non-contrast Thoracic inlet Pubic symphysis N/A 0.625 mm Non-contrast
Gated CTA Chest Thoracic inlet Diaphragm Bolus tracked 0.5-0.625 mm Retrospective gating chest
Flash CTA AP Diaphragm Pubic symphysis Immediate after chest 0.625 mm High pitch helical - no gating
Stent Delay (optional) Top of Stent Bottom of Stent 40 sec 0.625 mm Stent coverage
Plane Acquisition FOV Thickness/Increment Kernel IR Strength Notes
Axial Gated chest Chest 0.75 mm/0.75 mm Cardiac 3 Aortic root and valve
Axial Flash AP Abdomen/Pelvis 2 mm/2 mm Vascular 3 Abdominal aorta and branches
Coronal Both Full CAP 2.5 mm/2.5 mm Vascular 3 MIP full aorta
Sagittal Both Full CAP 2.5 mm/2.5 mm Vascular 3 Curved MPR entire aorta