title: Enhancement characteristics of benign and malignant focal peripheral nodules in the peripheral zone of the prostate gland studied using contrast-enhanced transrectal ultrasound.
abstract: OBJECTIVE
  To assess the value of contrast-enhanced grey-scale transrectal ultrasound (CETRUS) in predicting the nature of peripheral zone hypoechoic lesions of the prostate.
  
  
  METHODS
  Ninety-one patients with peripheral zone hypoechoic lesions on ultrasound were evaluated with CETRUS followed by lesion-specific and sextant transrectal ultrasound-guided biopsies. The enhancement patterns of the lesions were observed and graded subjectively using adjacent peripheral zone tissue as the reference. Time to enhancement (AT), time to peak intensity (TTP) and peak intensity (PI) were quantified within each nodule. Ultrasound findings were correlated with biopsy findings.
  
  
  RESULTS
  Transrectal ultrasound-guided biopsy of the hypoechoic lesions revealed prostate cancer in 44 patients and benign prostatic diseases in 47. The intensity of enhancement within the lesions were graded as no enhancement, increased, equal, or decreased compared with adjacent peripheral zone tissue in two, 30, five and seven in the prostate cancer group and 14, 15, four and 14 in the benign group, respectively. The difference was statistically significant (p<0.05). The peak enhancement intensity was found to be the most optimal discriminatory parameter (area under curve AUC 0.70; 95% CI: 0.58, 0.82).
  
  
  CONCLUSIONS
  Malignant hypoechoic nodules in the peripheral zone of the prostate are more likely to enhance early and more intensely on CETRUS. A non-enhanced hypoechoic peripheral zone lesion was more likely to be benign.
authors.affiliation: Department of Ultrasound, Chinese People's Liberation Army General Hospital, Beijing, PR China. yjc301301@163.com
authors.forename: J
authors.initials: J
authors.lastname: Tang
authors.forename: J-C
authors.initials: JC
authors.lastname: Yang
authors.forename: Y
authors.initials: Y
authors.lastname: Luo
authors.forename: J
authors.initials: J
authors.lastname: Li
authors.forename: Y
authors.initials: Y
authors.lastname: Li
authors.forename: H
authors.initials: H
authors.lastname: Shi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy / Q000379:methods; D003287:Contrast Media; D003937:Diagnosis, Differential; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008297:Male; D008875:Middle Aged; D010743:Phospholipids; D017430:Prostate-Specific Antigen / Q000097:blood; D011470:Prostatic Hyperplasia / Q000000981:diagnostic imaging / Q000473:pathology; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D013459:Sulfur Hexafluoride; D018084:Ultrasonography, Interventional / Q000379:methods
chemical_list: D003287:Contrast Media; D010743:Phospholipids; C420843:contrast agent BR1; D017430:Prostate-Specific Antigen; D013459:Sulfur Hexafluoride