title: Peripheral hypoechoic lesions of the prostate: evaluation with color and power Doppler ultrasound.
abstract: OBJECTIVE
  To assess the usefulness of color and power Doppler ultrasound in predicting the benignity and malignancy of the peripheral hypoechoic lesion of the prostate.
  
  
  METHODS
  Thirty-nine patients who had peripheral hypoechoic lesions on transrectal ultrasound were evaluated with color and power Doppler ultrasound followed by lesion-specific transrectal ultrasound-guided biopsies. The interpretation of color and power Doppler ultrasound was not performed separately and flow signals were categorized using a combination of the two modalities. The amount of flow signals within the lesion was evaluated and categorized into three groups: increased/equal/decreased flow compared to surrounding normal tissue on ultrasound. Doppler spectra could be obtained from the lesions in 23 patients. The amount of flow signals and resistive indexes of the spectra of the lesions were compared with those of surrounding normal tissue using the Mann-Whithney U test.
  
  
  RESULTS
  Transrectal ultrasound-guided biopsy of the hypoechoic lesions revealed prostate cancer in 20 patients and benign prostatic diseases in 19. Flow signals within the lesions were of increased/equal/decreased flow compared to surrounding normal tissue in 16/2/2 in the prostate cancer group and 3/9/7 in the benign disease group, respectively. The difference was statistically significant (p = 0.0003). Resistive indexes of the lesion were 0.58-1.0 (mean 0.75) in the prostate cancer group and 0.57-1.0 (mean 0.80) in the benign disease group, and there was no significant difference between the two groups (p = 0.82). If we consider an increased flow signal within a peripheral hypoechoic lesion as a sign of prostate cancer, color power Doppler ultrasound has a sensitivity of 80%, a specificity of 84%, and an accuracy of 82%.
  
  
  CONCLUSIONS
  Evaluation of peripheral hypoechoic lesions of the prostate with color and power Doppler may enhance the diagnostic capability of transrectal ultrasound.
authors.affiliation: Department of Radiology, Sungkyunkwan University School of Medicine, Seoul, Korea. radjycho@samsung.co.kr
authors.forename: J Y
authors.initials: JY
authors.lastname: Cho
authors.forename: S H
authors.initials: SH
authors.lastname: Kim
authors.forename: S E
authors.initials: SE
authors.lastname: Lee
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle; D003937:Diagnosis, Differential; D019160:Endosonography; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011470:Prostatic Hyperplasia / Q000000981:diagnostic imaging* / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D012016:Reference Values; D012680:Sensitivity and Specificity; D018615:Ultrasonography, Doppler, Color