[Reliable diagnosis of cystic renal lesions].

CLINICAL/METHODICAL ISSUE: Cystic renal lesions are commonly seen during routine ultrasound examinations of the abdomen. STANDARD RADIOLOGICAL
METHODS: Some cystic renal lesions cannot be sufficiently characterized using native ultrasound. In these cases additional imaging might be necessary. METHODICAL INNOVATIONS: Contrast-enhanced ultrasound (CEUS) is a reliable imaging modality to characterize cystic renal lesions. Contrast enhancement of septations and the cystic wall are visualized in high resolution. This information helps to categorize the cystic renal lesions applying the CEUS Bosniak classification. This classification helps to estimate the probability of a malignant etiology of cystic renal lesions. PERFORMANCE: Using CEUS, cystic renal lesions can be characterized with a high sensitivity and specificity. ACHIEVEMENTS: The advantages of CEUS include that there is no effect on the function of the kidneys or the thyroid gland and no radiation exposure. In some cases, additional cross-sectional imaging is necessary to optimize diagnostic accuracy. PRACTICAL RECOMMENDATIONS: CEUS is a helpful imaging modality to characterize cystic renal lesions, to avoid unnecessary follow-ups and to detect malignant cystic renal lesions.