The measurement of membranous urethral length using transperineal ultrasound prior to radical prostatectomy

Sean F. Mungovan*, Henk B. Luiting, Petra L. Graham, Jaspreet S. Sandhu, Oguz Akin, Lewis Chan, Manish I. Patel

*Corresponding author for this work

    Research output: Contribution to journalArticlepeer-review

    3 Citations (Scopus)
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    Objective: To compare preoperative membranous urethral length (MUL) measurements using magnetic resonance imaging (MRI) with two-dimensional transperineal ultrasound imaging (TPUS) in two supine positions on two separate days in men prior to radical prostatectomy. Materials and methods: MUL was prospectively measured in 18 male volunteers using MRI and on two separate occasions in two different patient positions using TPUS; the patient supine with the knees extended (Supine) and supine with the knees flexed to 70 degrees (Supine KF). Agreement between TPUS and MRI measurements of MUL was assessed using Bland-Altman method comparison techniques and a two-way mixed-effects single measures intraclass correlation (ICC). Test-retest reliability was assessed using a two-way random effects single measures ICC. Results: The mean difference in MUL measurements between MRI and i) TPUS Supine was −0.8 mm (95% limits of agreement (LOA): −3.2, 1.7) and ii) TPUS Supine KF was −0.8mm (95% LOA: −3.5, 1.9). ICC indicated a point estimate of excellent agreement between MRI and TPUS Supine ICC 0.93 (95% CI: 0.76, 0.98) and TPUS Supine KF ICC 0.91 (95%CI 0.79, 0.97). There was excellent agreement between TPUS Supine and TPUS Supine KF (ICC 0.98, 95% CI: 0.96, 0.99) with a mean difference of 0.3mm (95% LOA: −1.2 to 1.3mm). Conclusions: Preoperative MUL can be reliably measured using TPUS and demonstrates excellent agreement with MRI measurements of MUL. TPUS provides clinicians with an accessible non-invasive alternative to MRI for the measurement of MUL that can be used in outpatient urological settings and for patients where MRI is contraindicated.

    Original languageEnglish
    Pages (from-to)263-268
    Number of pages6
    JournalScandinavian Journal of Urology
    Issue number4
    Early online date25 Jul 2018
    Publication statusPublished - 2018

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    Copyright the Author(s) 2018. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.

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