Cystic liver lesions are frequently detected incidentally. Most of these lesions are benign, simple cystic lesions. However, up to 5% are complex cystic liver lesions, which require different management strategy. The purpose is to provide a practical approach for differentiating predominantly cystic lesions of the liver based on the CT and MR imaging findings.

Cystic liver lesions can be divided into different categories: benign, neoplastic, infectious or inflammatory and miscellaneous lesions. Clinical information can be important for adequate diagnosis especially in infectious and miscellaneouslesions. However, most patients present without symptoms or atypical abdominal pain or discomfort with coincidental discovery of a cystic liver lesion. Therefore imaging is the utmost important for characterizing these cystic liver lesions. In this poster we will focus on the cystic liver lesions in the liver with normal parenchyma, without underlying (chronic) liver disease. A...

Simple cystic lesion: Simple cystic lesions mostly demonstrate a thin, regular wall, smoothly demarcated (Fig 1). This features is often seen like in simple biliary cysts (Fig 2). The content is homogeneous with water like density at CT and high signal intensity on MRI at T2-weighted images (Fig 3). Sometimes a thin peripheral located septum can be observed in simple biliary cysts (Fig 4 and 5). No treatment is requiredfor this type of lesions. Sometimes alcohol sclerosis or fenestration is performed because of mechanical complaints....

When using the practical guide as described, furthermost cystic liver lesions can easily be differentiated. Benign, simple cystic lesions present with a smooth, thin wall and occasionally with a peripherally located thin septum. Premalignant, neoplastic lesions demonstrate multiple enhancing internal septations. Multiple enhancing septations in combination with solid enhancing nodular components or a thick irregular enhancing wall with solid enhancing components can be observed in malignant, neoplastic lesions. Infectious lesions also demonstratean irregular thick wall, however frequently with a hypodense rim around the lesion in...

François Willemssen, MD Department of Radiology Erasmus MC Rotterdam 's Gravendijkwal 230 3000 CA Rotterdam The Netherlands email: [email protected]

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