title: New modalities for evaluation and surveillance of complex renal cysts.
abstract: OBJECTIVE
  The increased use of abdominal imaging has led to more frequent detection of incidental renal cysts. Since the inception of the Bosniak classification system, management of Bosniak I, III and IV cysts has been clearly defined, while evaluation and management of Bosniak II and IIF cysts have remained a clinical dilemma. Discussions of new imaging modalities are becoming increasingly prevalent in the radiological literature. In this context we performed a comprehensive review of the recent literature on complex renal cysts focusing on new imaging modalities, surveillance strategies and biopsy.
  
  
  METHODS
  We performed a comprehensive literature review of articles published from January 1, 1998 through December 31, 2013 via MEDLINE(®), EMBASE and the Cochrane Collection using a predetermined search strategy. All studies included were performed in humans older than 18 years, were written in English and had an abstract available for review. We grouped studies into 1 of 5 categories, ie computerized tomography, magnetic resonance imaging, ultrasound, biopsy and surveillance.
  
  
  RESULTS
  While computerized tomography and magnetic resonance imaging with and without contrast enhancement remain the gold standard to evaluate cystic lesions of the kidney, diffusion-weighted magnetic resonance imaging and contrast enhanced ultrasound have surfaced as new tools for assessment of complex cysts. Comparative effectiveness studies on these new imaging modalities are limited. Image guided biopsy has increasingly been shown to be useful for evaluation of intermediate (Bosniak II and IIF) complex cysts. We found few studies providing guidance on the duration and/or intensity of surveillance required for intermediate complex renal cysts.
  
  
  CONCLUSIONS
  Although new and enhanced techniques are in development and may be useful in the future management of complex renal cysts, there is a paucity of data regarding the value of these new techniques. Future research should focus on surveillance of intermediate complex renal cysts, particularly on the ideal frequency and type of imaging required.
authors: Department of Urology, Loyola University Medical Center, Maywood, Illinois. Electronic address: cellimoottil@lumc.edu.
authors: Chandy
authors: C
authors: Ellimoottil
authors: Department of Urology, Loyola University Medical Center, Maywood, Illinois.
authors: Kristin A
authors: KA
authors: Greco
authors: Department of Urology, Loyola University Medical Center, Maywood, Illinois.
authors: Spencer
authors: S
authors: Hart
authors: Department of Radiology, Loyola University Medical Center, Maywood, Illinois.
authors: Tejas
authors: T
authors: Patel
authors: Department of Radiology, Loyola University Medical Center, Maywood, Illinois.
authors: M Mukarram
authors: MM
authors: Sheikh
authors: Department of Urology, Loyola University Medical Center, Maywood, Illinois.
authors: Thomas M T
authors: TM
authors: Turk
authors: Department of Urology, Loyola University Medical Center, Maywood, Illinois.
authors: Robert C
authors: RC
authors: Flanigan
mesh_terms: D001706:Biopsy; D006801:Humans; D052177:Kidney Diseases, Cystic / Q000175:diagnosis* / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography
keywords: classification; cystic; cysts; diagnostic imaging; kidney; kidney diseases