CT AND MRI IMAGING CHARACTERISTICS OF ADRENAL PHEOCHROMOCYTOMA

Abstract

Objective: To describe the computed tomography (CT) and magnetic
resonance imaging (MRI) characteristics of adrenal pheochromocytoma.
Methods: A cross-sectional descriptive study was conducted on 63
patients diagnosed with pheochromocytoma at Bach Mai Hospital. Age,
sex, hypertension, and tumor location were recorded at the patient level;
tumor size and imaging features on CT (cystic degeneration, necrosis,
calcification, contrast washout rate) and MRI (cystic degeneration, T2-
weighted signal, lightbulb sign, diffusion restriction on the ADC map)
were recorded at the tumor level.
Results: Mean age was 47.1 years (range 11–74); female/male ratio
was 33/30. Hypertension was present in 73.0% of patients (n=63). Tumors
were more commonly located on the right side (65.1%). Mean tumor size
was 48.2mm, with 80.6% of tumors larger than 30mm. CT was performed
in 57 tumors (85.1%) and MRI in 19 tumors (28.4%). On CT, the rates of
cystic degeneration, necrosis, and calcification were 47.4%, 33.3%, and
17.5%, respectively. On MRI, T2 hyperintensity was present in 89.5%,
diffusion restriction on ADC in 78.9%, while the lightbulb sign was seen
in only 31.6%.
Conclusion: Pheochromocytoma shows diverse imaging features on
CT and MRI, with T2 hyperintensity and diffusion restriction on MRI being
the most frequently observed signs, while a contrast washout rate >60%
was fairly common but not be used alone to exclude pheochromocytoma.
As this study lacked a control group, the differential diagnostic value of
these features cannot be confirmed.