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Zone Volume (zone + volume)

Distribution by Scientific Domains
Medical Sciences87%

Kinds of Zone Volume

  • transition zone volume
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    Selected Abstracts

    Comparison of prostate and transition zone volume measured by the ellipsoid and planimetric methods with transrectal ultrasonography before seed implantation of prostate cancer

    INTERNATIONAL JOURNAL OF UROLOGY, Issue 2 2008
    Tetsuhiro Ikeda
    Abstract: A total of 122 men who were diagnosed with localized prostatic cancer underwent transrectal ultrasound and the volumes of their prostates and transitional zones were obtained using the planimetric method and the ellipsoid method. Mean age was 64.2 ±13.4 (48.2,85.8), and mean preimplant prostate specific antigen was 6.01 ± 2.35 mg/mL (0.92,15.5). The clinical stage was T1c in 70 patients, T2a in 46 and T2b in 6. Prostatic volumes and transitional zone volumes obtained by the planimetric method were 18 % and 39% greater than those obtained by the ellipsoid method, respectively. There were significant differences between the volumes obtained by the two different methods. However, there was a good correlation between the prostatic volume and the transitional zone volume obtained by both the ellipsoid method (r = 0.851) and the planimetric method (r = 0.908). The regression line of the prostate volume between these two methods was calculated as . [source]

    Prostate-specific antigen adjusted for the transition zone volume as a second screening test: A prospective study of 248 cases

    INTERNATIONAL JOURNAL OF UROLOGY, Issue 7 2006
    SEOK-HO KANG
    Aim:, This study was conducted to verify the effectiveness of prostate-specific antigen adjusted for the transition zone volume (PSATZ), and its availability as a second screening test for prostate cancer detection. Materials and methods:, Total prostate-specific antigen (PSA) and free PSA was measured in male patients who visited our outpatient department for voiding difficulty or screening for prostate cancer. Patients who had an intermediate PSA level between 4.0 and 10.0 ng/mL, with an apparently normal prostate on a digital rectal examination, were enrolled. PSATZ, free-to-total PSA ratio (F/T ratio) and PSA density (PSAD) were calculated and statistical comparisons between biopsy-positive (cancer) and biopsy-negative patients (benign) were conducted. Results:, Of 248 patients, 51 (20.6%) had prostate cancer and 197 (79.4%) had benign prostatic hyperplasia (BPH) on pathologic examination. Mean PSA, PSAD, F/T ratio and PSATZ were 7.48 ± 1.77 ng/mL, 0.23 ± 0.09 ng/mL per mL, 0.14 ± 0.08 and 0.71 ± 0.44 ng/mL per mL in patients with prostate cancer and 6.59 ± 1.60 ng/mL, 0.16 ± 0.07 ng/mL per mL, 0.21 ± 0.11 and 0.36 ± 0.30 ng/mL per mL in patients with benign, respectively. Receiver operating characteristics (ROC) curve analysis demonstrated that PSATZ predicted the biopsy outcome better than F/T ratio. With a cut-off value of 0.37 ng/mL per mL, PSATZ had a sensitivity of 74.5% and a specificity of 72.6% for predicting prostate cancer. The maximal cut-off value that preserves 100% of sensitivity was 0.2, and at this cut-off value, 16.1% of unnecessary biopsies could be reduced. Conclusions:, Prostate-specific antigen adjusted for the transition zone volume may be more useful than other strategies in detecting prostate cancer in patients with intermediate PSA levels of 4.0,10.0 ng/mL. It can be used as a second screening test to reduce unnecessary biopsy. [source]

    Clinical efficacy of prostate cancer detection using power doppler imaging in American and Japanese men

    JOURNAL OF CLINICAL ULTRASOUND, Issue 4 2002
    Koji Okihara MD
    Abstract Purpose The aim of this study was to compare the detection rates of tumor vascular flow as measured by power Doppler imaging (PDI) in 2 populations and to determine whether PDI can reduce the number of unnecessary prostate biopsies in men with serum prostate-specific antigen (PSA) concentrations less than 10.1 ng/ml. Methods The patient populations were Japanese (group 1) and American (group 2) men with either serum PSA concentrations of 4.1,10.0 ng/ml or abnormal findings on digital rectal examination (DRE) plus PSA concentrations less than 4.1 ng/ml. We compared the overall diagnostic accuracy of DRE, gray-scale transrectal sonography (TRUS), and PDI between the 2 groups. Results In total, 275 men were studied, 154 in group 1 and 121 in group 2. Cancer was identified in 27% of men in group 1 and in 60% of group 2. Men with cancer in both groups differed significantly in age, peripheral zone volume, and mean number of positive biopsy cores. The sensitivity and specificity of PDI in group 2 were significantly inferior to those in group 1. The negative predictive value (NPV) of PDI was significantly higher for group 1 than for group 2. The NPV of PDI in group 1 was equivalent to that for the combination of DRE and TRUS, whereas the NPV for PDI in group 2 was significantly inferior to that of DRE and TRUS. Conclusions Tumor vascularity could be detected by PDI more effectively in Japanese men with cancer than in American men with cancer. We hypothesize that this difference was a result of larger cancer volumes and smaller prostates in the Japanese men. PDI did not provide any performance advantage over DRE and TRUS in avoiding unnecessary biopsies. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 30:213,221, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/jcu.10054 [source]

    Analysis of stirred tanks with two-zone models

    AICHE JOURNAL, Issue 10 2009
    Ville Alopaeus
    Abstract Stirred tank turbulence and fluid flow characteristics are analyzed based on a two-zone model. Instead of using the zonal model for stirred tank performance prediction as often proposed in the literature, the zoning is used here as a tool for mixing analysis. A systematic zoning approach is proposed, where the tank is divided into two nested regions. By gradually increasing the inner zone volume, continuous curves can be obtained for turbulent energy dissipation distribution and pumping numbers between the zones as functions of the zone sizes. It is shown here that these curves can be used as a powerful tool for visualizing stirred tank performance. They can be used, e.g., in impeller performance comparisons and analysis of mixing characteristics with changing rheology, or to examine various numerical aspects related to stirred tank CFD modeling. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source]

    The impact of targeted training, a dedicated protocol and on-site training material in reducing observer variability of prostate and transition zone dimensions measured by transrectal ultrasonography, in multicentre multinational clinical trials of men with symptomatic benign prostatic enlargement

    BJU INTERNATIONAL, Issue 1 2007
    Philip S. Murphy
    OBJECTIVE To assess the variability of a standardized protocol of transrectal ultrasonography (TRUS), with targeted training, and compare it to the variability in other multicentre clinical trials, as TRUS-estimated total prostate volume (TPV) and transition zone volume (TZV) are considered important efficacy endpoints in assessing new drug therapies for benign prostatic enlargement (BPE), but standardizing TRUS remains a challenge in such studies. PATIENTS AND METHODS In all, 174 patients with BPE in the placebo arm of a 30-centre clinical trial were analysed at baseline, 13 and 26 weeks with TRUS, to extract TPV and TZV values. All TRUS operators received training in the standardized methods, which was supplemented at the outset by a compact disc-based video. RESULTS The mean (sd) changes from baseline in TPV at 13 and 26 weeks were ,,2.9 (8.9) and ,1.9 (8.5) mL, respectively; the respective mean changes from baseline in TZV were ,1.2 (6.4) and +,0.7 (7.8) mL. For TPV, 80% of the measurements had differences of +,5.2 to ,13.4 mL at 13 weeks, and +,8.0 to ,,10.9 mL at 26 weeks. For TZV, 80% of the differences were +,5.8 to ,,7.4 at 13 weeks, and +,9.3 to ,6.5 mL at 26 weeks. CONCLUSION The performance of TRUS compared favourably with similar published multicentre studies, which we suggest relates in part to the careful implementation of the protocol. We showed that diligent implementation of a detailed protocol, supplemented by targeted training of investigators and provision of on-site training material, promoted consistent acquisition and successful derivation of key clinical trial endpoints. Quantifying the variability of such endpoints will enable us to track deployment quality for future clinical trials, and will ensure that trials are sufficiently powered to define small changes in prostate size. [source]

    Comparison of prostate and transition zone volume measured by the ellipsoid and planimetric methods with transrectal ultrasonography before seed implantation of prostate cancer

    INTERNATIONAL JOURNAL OF UROLOGY, Issue 2 2008
    Tetsuhiro Ikeda
    Abstract: A total of 122 men who were diagnosed with localized prostatic cancer underwent transrectal ultrasound and the volumes of their prostates and transitional zones were obtained using the planimetric method and the ellipsoid method. Mean age was 64.2 ±13.4 (48.2,85.8), and mean preimplant prostate specific antigen was 6.01 ± 2.35 mg/mL (0.92,15.5). The clinical stage was T1c in 70 patients, T2a in 46 and T2b in 6. Prostatic volumes and transitional zone volumes obtained by the planimetric method were 18 % and 39% greater than those obtained by the ellipsoid method, respectively. There were significant differences between the volumes obtained by the two different methods. However, there was a good correlation between the prostatic volume and the transitional zone volume obtained by both the ellipsoid method (r = 0.851) and the planimetric method (r = 0.908). The regression line of the prostate volume between these two methods was calculated as . [source]