title: Doppler resistive index in benign prostatic hyperplasia: correlation with ultrasonic appearance of the prostate and infravesical obstruction.
abstract: OBJECTIVE
  This study was designed to characterize the resistive index (RI) of prostatic blood flows obtained by transrectal power Doppler sonography (TRPDS) in benign prostatic hyperplasia (BPH).
  
  
  METHODS
  In 140 patients with lower urinary tract symptoms, the RI was measured using TRPDS and compared with age and planimetric parameters of the prostate obtained by conventional transrectal sonography. In addition, the RI was related with pressure flow studies.
  
  
  RESULTS
  The RI was significantly higher in patients with BPH (0.72+/-0.06, p<0.0001) than those with a normal prostate (0. 64+/-0.04). Although the RI correlated significantly with age and all prostatic planimetric parameters, multiple regression analysis revealed that age and presumed circle area ratio were independent predictors for RI. The RI was also higher in patients with infravesical obstruction than those without (0.74+/-0.06 vs. 0. 70+/-0.05, p<0.005). There was a significant correlation between RI and urodynamic parameters obtained in pressure flow studies. Out of 33 patients with obstruction, 28 (85%) had an RI of 0.7 or more, while 11 out of 24 patients (46%) without obstruction had an RI less than 0.7.
  
  
  CONCLUSIONS
  The RI is promising as a new parameter to estimate the intraprostatic pressure to investigate BPH. Its value to represent urodynamic information during voiding remains to be studied.
authors.affiliation: Department of Urology, Kyoto Prefectural University of Medicine, Kyoto, Japan. mkojima@cg7.so-net.ne.jp
authors.forename: M
authors.initials: M
authors.lastname: Kojima
authors.forename: A
authors.initials: A
authors.lastname: Ochiai
authors.forename: Y
authors.initials: Y
authors.lastname: Naya
authors.forename: K
authors.initials: K
authors.lastname: Okihara
authors.forename: O
authors.initials: O
authors.lastname: Ukimura
authors.forename: T
authors.initials: T
authors.lastname: Miki
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology / Q000502:physiology; D001707:Biopsy, Needle; D016001:Confidence Intervals; D019160:Endosonography / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011467:Prostate / Q000098:blood supply* / Q000000981:diagnostic imaging / Q000473:pathology*; D011470:Prostatic Hyperplasia / Q000150:complications / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology*; D012039:Regional Blood Flow; D012044:Regression Analysis; D012680:Sensitivity and Specificity; D018615:Ultrasonography, Doppler, Color / Q000379:methods; D001748:Urinary Bladder Neck Obstruction / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D014555:Urination Disorders / Q000150:complications / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D014563:Urodynamics; D014655:Vascular Resistance