Full length article| Volume 220, P88-95, January 2018

Reproducibility of the transvaginal sonographic assessment of bladder wall thickness

Published:November 21, 2017DOI:



      To assess whether transvaginal sonographic measurements of bladder wall thickness (BWT) have adequate reproducibility to detect differences in BWT potentially indicative of detrusor overactivity in women with overactive bladder.

      Study design

      Three reproducibility studies were undertaken to assess (A) total measurement error, (B) intra-observer variability and (C) inter-observer measurement in the interpretation of scans. Women recruited to the Bladder Ultrasound Study underwent a transvaginal ultrasound scan to obtain a measurement of BWT. When a second observer was available, women who agreed to have two transvaginal scans by different operators were recruited into study A. For study B the first observer reassessed a sample of the recorded images at a later date whilst for study C, a random selection of BWT images were read by a second assessor. Analytical variability, percentage of variability attributable to measurement error, within-person variation and the smallest real difference detectable were estimated.


      One hundred and twenty-one women took part: 27 had repeat scans, 37 had scans re-read by the same observer, and 57 had scans read by two observers. In study A, 39% of the total variability in measurements was explained by measurement error (the remainder to within person change); the standard deviation (SD) of measurement error was 0.76 mm and the smallest detectable clinical difference was 2.1 mm. The SD of measurement error from scan interpretation was 0.42 mm within observers (study B) and 0.35 mm between observers (study C).


      The high levels of measurement error for a small measurement of BWT means it is unlikely Transvaginal ultrasound measurements have insufficient reliability and reproducibility to be an accurate diagnostic test.


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        • Haylen B.T.
        • et al.
        An International Urogynecological Association (IUGA)/International Continence Society (ICS) joint report on the terminology for female pelvic floor dysfunction.
        Int Urogynecol J. 2010; 21: 5-26
        • Foon R.
        • Toozs-Hobson P.
        • Latthe P.
        Prophylactic antibiotics to reduce the risk of urinary tract infections after urodynamic studies.
        Cochrane Database Syst Rev. 2012; 10: CD008224
        • Khullar V.
        • et al.
        Ultrasound: a noninvasive screening test for detrusor instability.
        Br J Obstet Gynaecol. 1996; 103: 904-908
        • Rachaneni S.
        • et al.
        Bladder ultrasonography for diagnosing detrusor overactivity: test accuracy study and economic evaluation.
        Health Technol Assess. 2016; 20: 1-150
        • Khullar V.
        • et al.
        A novel technique for measuring bladder wall thickness in women using transvaginal ultrasound.
        Ultrasound Obstet Gynecol. 1994; 4: 220-223
        • Vaz S.
        • et al.
        The case for using the repeatability coefficient when calculating test-retest reliability.
        PLoS One. 2013; 8: e73990
        • Beckerman H.
        • et al.
        Smallest real difference: a link between reproducibility and responsiveness.
        Qual Life Res. 2001; 10: 571-578
        • Pannek J.
        • et al.
        Clinical usefulness of ultrasound assessment of detrusor wall thickness in patients with neurogenic lower urinary tract dysfunction due to spinal cord injury: urodynamics made easy?.
        World J Urol. 2013; 31: 659-664
        • Kuo H.C.
        Measurement of detrusor wall thickness in women with overactive bladder by transvaginal and transabdominal sonography.
        Int Urogynecol J Pelvic Floor Dysfunct. 2009; 20: 1293-1299
        • Lekskulchai O.
        • Dietz H.P.
        Detrusor wall thickness as a test for detrusor overactivity in women.
        Ultrasound Obstet Gynecol. 2008; 32: 535-539
        • Panayi D.C.
        • et al.
        Transvaginal ultrasound measurement of bladder wall thickness: a more reliable approach than transperineal and transabdominal approaches.
        BJU Int. 2010; 106: 1519-1522
        • Tubaro A.
        • Oelke K.V.
        • Wijkstra M.
        • Tretter R.
        • Stow B.
        Inter and intra-reader variability of transvaginal bladder wall thickness measurements: results from the SHRINK study.
        ICS conference abstracts. 2013;
        • Amer S.A.
        • et al.
        An evaluation of the inter-observer and intra-observer variability of the ultrasound diagnosis of polycystic ovaries.
        Hum Reprod. 2002; 17: 1616-1622