Imaging of the adrenal gland lesions

Abstract

With the steep increase in the use of cross-sectional imaging in recent years, the incidentally detected adrenal lesion, or "incidentaloma", has become an increasingly common diagnostic problem for the radiologist, and a need for an approach to classifying these lesions as benign, malignant or indeterminate with imaging has spurred an explosion of research. While most incidentalomas represent benign disease, typically an adenoma, the possibility of malignant involvement of the adrenal gland necessitates a reliance on imaging to inform management decisions. In this article, we review the literature on adrenal gland imaging, with particular emphasis on computed tomography, magnetic resonance imaging, and photon-emission tomography, and discuss how these findings relate to clinical practice. Emerging technologies, such as contrast-enhanced ultrasonography, dual-energy computed tomography, and magnetic resonance spectroscopic imaging will also be briefly addressed.

Radiology of the adrenal incidentalomas. Review of the literature

“…Th e adrenals can be delineated in nearly all the patients with MRI (Schteingart et al 2005). Sensitivity, specifi city, positive predictive value and negative predictive value for CT and MRI range from 90% to almost 100% according to various studies Anagnostis et al 2009;Boland 2011;Sundin 2012;Herr et al 2014).…”

“…Myelolipomas can also contain small calcifi cations (Cyran et al 1996;Adusumilli and Ramchandani 2001). On MRI, there is loss of signal on fat-saturated MRI (Herr et al 2014).…”

“…Bilateral metastatic involvement occurs in up to 50% of cases (Boland et al 2008). Secondary involvement of the adrenal gland occurs in 4% of cases of nonHodgkin lymphoma at CT and 25% in post-mortem studies (Zhou et al 2012;Herr et al 2014). …”

“…Th is study is the only study that describes the full epidemiological characteristics of the presentation of the AI. Th e majority of the studies aft er 2000 are restricted to the incidence of AI in CT or MRI or both (Blake et al 2010;Boland et al 2008;Jain 2013;Kim et al 2013;Herr et al 2014;Paterson et al 2014).…”

Imaging Modalities for Adrenal Lesions

“…The formula of APW is x 100 The formula of RPW is x 100 If there is a greater washout with a generally accepted threshold of ≥60% APW, the lesion is presumably benign. Also if the RPW values ≥40%, the lesion is more likely benign [10]. 3.…”