title: Comparison of prostate volume measured by transrectal ultrasonography and MRI with the actual prostate volume measured after radical prostatectomy.
abstract: OBJECTIVE
  To compare the prostate volume, as measured by transrectal ultrasonography (TRUS) and by MRI, with that of the actual prostate volume measured after a radical prostatectomy (RRP).
  
  
  METHODS
  This prospective study included 21 patients who had undergone RRP. TRUS prostate volumes were calculated using the prolate ellipsoid volume formula, with the anteroposterior diameter measured from axial (TRUS-V1) and mid-sagittal images (TRUS-V2). Two prolate ellipsoid volumes (MRI-EV1 and MRI-EV2) were calculated from the MRI using the same method, and planimetric volume (MRI-PV). The actual prostate volume (Actual-V) was measured in a measuring jug within 1 h after RRP.
  
  
  RESULTS
  Mean of Actual-V was 40.3ml (21.0-82.0). In paired sample tests, the correlation coefficients (R) for all methods were over 0.8. In a Student's t test (paired), MRI-PV (p = 0.620), MRI-EV2 (p = 0.703) and TRUS-V1 (p = 0.099) showed no significant differences compared to the Actual-V. The linear regression models of these three methods were y = 1.025x - 0.268, y = 0.946x + 2.979 and y = 1.046x + 0.381, respectively.
  
  
  CONCLUSIONS
  Between two TRUS volumes, TRUS-V1 was shown to be superior to TRUS-V2. In MRI, MRI-EV2 was more accurate than MRI-EV1. However, MRI-PV was the most accurate method. TRUS-V1 and MRI-EV2 could be used instead of MRI-PV in general clinical settings.
authors.affiliation: Department of Urology, Seoul National University Hospital, Seoul, Korea.
authors.forename: Chang Wook
authors.initials: CW
authors.lastname: Jeong
authors.forename: Hyoung Keun
authors.initials: HK
authors.lastname: Park
authors.forename: Sung Kyu
authors.initials: SK
authors.lastname: Hong
authors.forename: Seok-Soo
authors.initials: SS
authors.lastname: Byun
authors.forename: Hak Jong
authors.initials: HJ
authors.lastname: Lee
authors.forename: Sang Eun
authors.initials: SE
authors.lastname: Lee