title: The relationship of penile rigidity and intracavernous vascular resistance in potent men during intracavernous pharmacological testing.
abstract: OBJECTIVE
  We studied the relationship of penile rigidity and intracavernous vascular resistance in potent men during intracavernous pharmacological testing.
  
  
  METHODS
  Enrolled in our study were 19 potent men undergoing intracavernous pharmacological testing for various reasons. Hemodynamic changes in response to the intracavernous injection of 20 microg. prostaglandin E1 were assessed by color Doppler sonography with simultaneous RigiScan (Dacomed Corp., Minneapolis, Minnesota) monitoring of penile rigidity. The relationship of penile rigidity and intracavernous vascular resistance was determined by correlating hemodynamic data with recorded penile rigidity values.
  
  
  RESULTS
  Maximal mean rigidity plus or minus standard deviation of the penile tip and base after intracavernous injection of prostaglandin E1 was 76.8% +/- 8.5% and 97.3% +/- 4.7%, respectively. Penile tip and base rigidity correlated positively with the resistive index (r = 0.69 and 0.75, p <0.0001) and negatively with end diastolic velocity (r = -0.62 and -0.70, respectively, p <0.0001). The formula, rigidity = -128 + 195 x resistive index, was derived to describe the linear regression of penile base rigidity and the resistive index. The formula, rigidity = 59.8 - 3.3 x end diastolic velocity, was derived to describe the linear regression of penile base rigidity and end diastolic velocity.
  
  
  CONCLUSIONS
  Penile rigidity correlated strongly with intracavernous vascular resistance in potent men during intracavernous pharmacological testing. The resistive index and end diastolic velocity of the cavernous arteries may each be used to estimate penile rigidity quantitatively.
authors.affiliation: Department of Urology, Hsin-Chu Hospital, Taipei, Taiwan, Republic of China.
authors.forename: J H
authors.initials: JH
authors.lastname: Chen
authors.forename: S P
authors.initials: SP
authors.lastname: Liu
authors.forename: J T
authors.initials: JT
authors.lastname: Hsieh
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D010410:Penile Erection; D010413:Penis / Q000098:blood supply / Q000000981:diagnostic imaging / Q000502:physiology*; D018615:Ultrasonography, Doppler, Color; D014655:Vascular Resistance