Pearls and pitfalls of imaging of the adrenals
Functional adrenal pathology is typically suspected clinically and imaging is an important addition to the clinical and biochemical findings. On the other hand, incidentally found adrenal lesions are in majority of cases asymptomatic, or cause subtle hormonal disturbances with subclinical symptoms, and are primarily diagnosed on imaging, posing therefore a bigger challenge to a radiologist. Consequently, understanding pitfalls in MR imaging of adrenal lesions is of particular importance in diagnosing incidentalomas. Adrenal incidentalomas, of which common types are described in detail in chapter 'Adrenal incidentalomas', may appear on MR imaging studies with classical features, which lead to a highly confident diagnosis. However, adrenal incidentalomas may also show atypical features, which hamper the correct diagnosis and in some cases necessitate further non-radiological work-up and/or surgical treatment. Moreover, technique-related pitfalls may also cause diagnostic difficulties. This chapter aims to give a review of general pitfalls in MR imaging of adrenal lesions, related to technical aspects, diagnostic approach and atypical imaging features of some common adrenal lesions, with particular focus on incidentalomas. Pitfalls attributable to the occurrence of exceptionally uncommon lesions are also discussed. Guidelines in diagnostic approach and follow-up are provided, including supplementary alternative diagnostic tests used in problematic cases.