title: Nutcracker syndrome in children with gross haematuria: Doppler sonographic evaluation of the left renal vein.
abstract: BACKGROUND
  Nutcracker syndrome is characterized by gross haematuria caused by left renal vein (LRV) entrapment.
  
  
  OBJECTIVE
  To assess the role of LRV ultrasonography in the diagnosis of the nutcracker syndrome in children.
  
  
  METHODS
  Twelve children (eight male, four female; mean age 12.8 years) with venographically confirmed nutcracker syndrome (LRV-IVC pressure gradient > or = 3 mm Hg) underwent LRV sonography including Doppler spectral analysis (n=7). The diameter and peak velocity (PV) were measured at two sites of the LRV (renal hilum and aortomesenteric portion). The US findings of nutcracker syndrome were compared with those of 20 control subjects using the t-test. We identified the optimal cut-off value of the US parameters for the diagnosis of the nutcracker syndrome using ROC analysis.
  
  
  RESULTS
  The PV at the aortomesenteric portion and the ratio of the PV between the two measured points showed significant differences between the two groups (P<0.0001). The optimum cut-off values were found to be 4.7 for the PV ratio (sensitivity 100%, specificity 90%, accuracy 93%), and 93 cm/s for the PV at the aortomesenteric portion (sensitivity 100%, specificity 85%, accuracy 89%).
  
  
  CONCLUSIONS
  LRV sonography, including Doppler spectral analysis, can demonstrate LRV entrapment haemodynamically.
authors.affiliation: Department of Radiology, Institute of Radiation Medicine, Seoul National University College of Medicine, Clinical Research Institute, Seoul National University Hospital, 28 Yongon-dong, Chongno-gu, Seoul, 110-744, Republic of Korea.
authors.forename: Jung-Eun
authors.initials: JE
authors.lastname: Cheon
authors.forename: Woo Sun
authors.initials: WS
authors.lastname: Kim
authors.forename: In-One
authors.initials: IO
authors.lastname: Kim
authors.forename: Seung Hyup
authors.initials: SH
authors.lastname: Kim
authors.forename: Kyung Mo
authors.initials: KM
authors.lastname: Yeon
authors.forename: Il Soo
authors.initials: IS
authors.lastname: Ha
authors.forename: Hae Il
authors.initials: HI
authors.lastname: Cheong
authors.forename: Yong
authors.initials: Y
authors.lastname: Choi
mesh_terms: D000293:Adolescent; D001783:Blood Flow Velocity; D002648:Child; D003251:Constriction, Pathologic; D005260:Female; D006417:Hematuria / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D008297:Male; D016491:Peripheral Vascular Diseases / Q000000981:diagnostic imaging* / Q000503:physiopathology; D012372:ROC Curve; D012082:Renal Veins / Q000000981:diagnostic imaging* / Q000503:physiopathology; D013577:Syndrome; D014463:Ultrasonography