Abstract
Objectives
To assess the necessity of additional imaging by comparing the
characteristics of adrenal lesions incidentally detected on abdominal, stone
protocol, and chest computed tomography (CT) with those obtained from a
second imaging modality specifically targeting the adrenal glands.
Methods
A total of 162 adrenal lesions imaged in 112 patients with adrenal
incidentalomas were retrospectively analyzed. Radiology reports were
reviewed for adrenal lesion laterality, location, number of lesions, maximum
diameter, the number of dimensions specified, lesion density on CT measured
in Hounsfield Units (HU), lesion characterization, presence of
heterogeneity, and functional status. Cohen’s Kappa test assessed the
agreement between the first and second imaging evaluations. Additionally,
sensitivity, specificity, positive predictive value, and negative predictive
value of the first imaging were calculated using adrenal-specific second
imaging as the reference standard.
Results
No concordance was found between the initial and follow-up imaging in terms
of HU measurements (κ=0.079; p=0.123). However, concordance ranging from
weak to excellent was observed regarding bilaterality, localization, lesion
count, diameter, and heterogeneity. Based on the second imaging reports as
reference, the sensitivity of the initial imaging for diagnosing adenoma and
myelolipoma was determined to be 26.49% and 42.85%, respectively. The
success rate of adenoma diagnosis was associated with the number of lesions
in the adrenal gland (≥2 lesions>single lesion), lesion size (>2
cm>≤ 2 cm), and location (left>right). Nine lesions initially reported
as<4 cm on the first imaging were found to be≥4 cm on the second imaging,
and seven lesions initially reported as unilateral were noted to be
bilateral on the second imaging. In eight patients, adrenal lesions were
detected on the first imaging, but the second imaging was reported as
normal.
Conclusion
A more detailed definition of adrenal incidentalomas, especially in terms of
heterogeneity and HU values in the first images in radiology reports, and
the use of a standard reporting system will guide clinical practice and
provide a cost-effective approach while avoiding unnecessary imaging and
radiation.
Keywords
Incidentaloma - adrenal - adenoma - tomography - magnetic resonance
