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CT Adrenal Mass Protocol

Last Updated: 2026-01-01 Author:

  • 1. Clinical Summary

    Series Phase Coverage
    Non-Contrast Non-contrast Diaphragm to Kidneys
    Portal Venous Contrast (70 sec delay) Diaphragm to Kidneys
    15 Minute Delay Contrast (900 sec delay) Diaphragm to Kidneys
    • Adrenal mass characterization
    • Adenoma vs metastasis
    • Incidentaloma workup

  • 2. Patient Prep

    • Position: Supine with arms raised
    • NPO Status: NPO 4 hours

  • 3. IV Contrast & Injection

    Parameter Value
    Agent Isovue 370
    Volume 1.5 mL/kg
    Flow Rate 3 mL/s
    Duration 40s
    Timing Method Empiric Delay (70s)

    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

    • THREE phases: 1) Non-contrast for absolute HU 2) Portal venous 70s 3) 15 MINUTE delayed for washout. All phases cover adrenals
    • Additional Recons: Calculate absolute washout: (Enhanced HU - Delayed HU)/(Enhanced HU - NC HU) x 100. >60% suggests adenoma. Measure HU in all phases
    • 20-22G IV. Patient must wait 15 min for delayed phase

    Safety First

    • Renal Function: Verify eGFR > 30
    • Allergy: Check allergy history. Explain 15 min delay
    • NC: lipid-rich adenoma < 10 HU. Portal venous: enhancement. 15 min delay: calculate washout (adenoma shows washout)
    • Patient wait time 15 min. Measure HU carefully with ROI in same location
Series Name Start Location End Location Delay Slice Thickness Notes
Scout Diaphragm Kidneys N/A N/A AP
Non-Contrast Diaphragm Kidneys N/A 2.5 mm Measure absolute HU in mass
Portal Venous Diaphragm Kidneys 70 sec 2.5 mm Enhanced HU measurement
15 Minute Delay Diaphragm Kidneys 900 sec 2.5 mm Delayed HU for washout calculation
Plane Acquisition FOV Thickness/Increment Kernel IR Strength Notes
Axial All phases Adrenals 2.5 mm/2.5 mm Standard 3 ROI measurements in mass
Axial All phases Adrenals 2.5 mm/2.5 mm Standard 3 Compare enhancement
Coronal Portal venous Adrenals 3 mm/3 mm Standard 3 Anatomic overview