title: Doppler ultrasonographic indices in diagnosing nutcracker syndrome in children.
abstract: To elucidate the Doppler ultrasonographic cut-off value of nutcracker syndrome causing hematuria in children, we analyzed Doppler spectral findings between 15 children with nutcracker syndrome and 15 age- and sex-matched normal control subjects. A follow-up Doppler ultrasound (US) was also performed in children with nutcracker syndrome when hematuria subsided completely after a median period of 1.7 years (range: 1.0-3.5 years) (relieved nutcracker syndrome). The peak velocity (PV) ratios of the left renal vein (LRV) were significantly higher in children with nutcracker syndrome than in those with relieved nutcracker syndrome (P<0.0001) and normal children (P<0.0001). The PV ratios of the LRV at the follow-up US were significantly higher than those in the control subjects (P=0.019). None of the 15 normal children showed PV ratios of the LRV>3.7, but five of the 15 children with relieved nutcracker syndrome without hematuria had PV ratios of 3.91-5.02. When we set the cut-off values for nutcracker syndrome at the mean+/-2 SD (mean: 2.95+/-0.92, range: 1.60-5.02) of 30 controls (normal children and relieved nutcracker without hematuria), the calculated cut-off value was 4.8, and the sensitivity and specificity were 100% and 93%, respectively. Given its high sensitivity, renal Doppler US can be used as a useful initial non-invasive test in the diagnosis of nutcracker syndrome in children with hematuria.
authors.affiliation: The Institute of Kidney Disease, Department of Pediatrics, Yonsei University College of Medicine, Severance Children's Hospital, Seoul, South Korea.
authors.forename: Jae Il
authors.initials: JI
authors.lastname: Shin
authors.forename: Jee Min
authors.initials: JM
authors.lastname: Park
authors.forename: Jae Seung
authors.initials: JS
authors.lastname: Lee
authors.forename: Myung Joon
authors.initials: MJ
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D001783:Blood Flow Velocity; D002648:Child; D003251:Constriction, Pathologic; D005260:Female; D006417:Hematuria / Q000209:etiology; D006801:Humans; D007674:Kidney Diseases / Q000000981:diagnostic imaging; D008297:Male; D016491:Peripheral Vascular Diseases / Q000000981:diagnostic imaging*; D012082:Renal Veins / Q000000981:diagnostic imaging* / Q000473:pathology*; D013577:Syndrome; D018608:Ultrasonography, Doppler