CT Protocol for Adrenal Pheochromocytoma Diagnosis

Initial Imaging Approach

If the adrenal mass shows >10 HU on non-contrast CT, further imaging is required as this finding is suspicious for pheochromocytoma 1

SPECT/CT should be considered a mandatory part of the study for precise localization 2, 3
CT parameters should include 100-130 kV with mAs modulation for optimal image quality 2
CT-based attenuation correction should be performed for accurate visualization of lesions 3

High-intensity adrenal uptake (more intense than liver) or inhomogeneous uptake with an enlarged gland on CT is abnormal and suggestive of pheochromocytoma 3

Approximately 1/3 of pheochromocytomas may demonstrate washout in the characteristic range of an adenoma, potentially leading to false negatives 1
CT-based attenuation correction can lead to enhanced physiological visualization of the adrenal medulla, potentially causing false-positive interpretations 3
Biochemical testing (plasma or 24-hour urinary metanephrines) must be performed before any invasive procedure, including biopsy, to exclude pheochromocytoma and avoid hypertensive crisis 5
For patients with confirmed biochemical evidence of pheochromocytoma, additional functional imaging such as MIBG scintigraphy, FDOPA-PET, or FDG-PET may be helpful to detect multifocal disease 5

Adrenal masses growing >5 mm/year should prompt consideration for adrenalectomy after repeating functional work-up 1