title: The usefulness of pulsatile flow detection in measuring resistive index in renal Doppler US.
abstract: OBJECTIVE
  To assess the usefulness of pulsatile flow detection (PFD), a newly developed function of color Doppler US, in measuring resistive index (RI) in renal Doppler US and to compare it with conventional color Doppler (CCD).
  
  
  METHODS
  Fifty-six kidneys in 31 patients were randomly selected and divided into two groups. In group A, RI was measured first with the aid of CCD, and then with PFD. In group B, data were obtained in the reverse order. The time required for each RI measurement was recorded in seconds. The quality of the Doppler spectral waveform was subjectively graded as 0, 1, or 2 and examination time and waveform quality were compared between PFD and CCD.
  
  
  RESULTS
  The time required to measure RI with PFD (PFD time) was less than with CCD (CCD time) (mean 42.7 secs vs. mean 70.3 secs; p = 0.031). There was no significant difference in PFD time between group A and B, but CCD time was shorter in group B (70.3 secs vs. 24.6 secs; p = 0.0004). Spectral waveform quality was not significantly different between PFD and CCD.
  
  
  CONCLUSIONS
  The time required to measure RI in kidneys can be shortened with the aid of the PFD function in color Doppler US without affecting the quality of the examination.
authors.affiliation: Department of Radiology, College of Medicine, Seoul National University Hospital, 28 Yongon-dong, Chongno-gu, Seoul 110-744, Korea. pinksu77@korea.com
authors.forename: Sun Ho
authors.initials: SH
authors.lastname: Kim
mesh_terms: D001783:Blood Flow Velocity / Q000502:physiology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007668:Kidney / Q000000981:diagnostic imaging*; D008297:Male; D011673:Pulsatile Flow / Q000502:physiology; D012079:Renal Circulation / Q000502:physiology; D018615:Ultrasonography, Doppler, Color