Noninvasive evaluation of bladder wall mechanical properties as a function of filling volume

Potential application in bladder compliance assessment

Ivan Nenadic, Lance Mynderse, Douglas Husmann, Mohammad Mehrmohammadi, Mahdi Bayat, Aparna Singh, Max Denis, Matthew W Urban, Azra Alizad, Mostafa Fatemi

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Purpose: We propose a novel method to monitor bladder wall mechanical properties as a function of filling volume, with the potential application to bladder compliance assessment. The proposed ultrasound bladder vibrometry (UBV) method uses ultrasound to excite and track Lamb waves on the bladder wall from which its mechanical properties are derived by fitting measurements to an analytical model. Of particular interest is the shear modulus of bladder wall at different volumes, which we hypothesize, is similar to measuring the compliance characteristics of the bladder. Materials and Methods: Three experimental models were used: 1) an ex vivo porcine model where normal and aberrant (stiffened by formalin) bladders underwent evaluation by UBV; 2) an in vivo study to evaluate the performance of UBV on patients with clinically documented compliant and noncompliant bladders undergoing UDS; and 3) a noninvasive UBV protocol to assess bladder compliance using oral hydration and fractionated voiding on three healthy volunteers. Results: The ex vivo studies showed a high correlation between the UBV parameters and direct pressure measurement (R2 = 0.84-0.99). A similar correlation was observed for 2 patients with compliant and noncompliant bladders (R2 = 0.89-0.99) undergoing UDS detrusor pressure-volume measurements. The results of UBV on healthy volunteers, performed without catheterization, were comparable to a compliant bladder patient. Conclusion: The utility of UBV as a method to monitor changes in bladder wall mechanical properties is validated by the high correlation with pressure measurements in ex vivo and in vivo patient studies. High correlation UBV and UDS in vivo studies demonstrated the potential of UBV as a bladder compliance assessment tool. Results of studies on healthy volunteers with normal bladders demonstrated that UBV could be performed noninvasively. Further studies on a larger cohort are needed to fully validate the use of UBV as a clinical tool for bladder compliance assessment.

Original languageEnglish (US)
Article numbere0157818
JournalPLoS One
Volume11
Issue number6
DOIs
StatePublished - Jun 1 2016

Fingerprint

bladder
compliance
Compliance
mechanical properties
Urinary Bladder
Ultrasonics
Mechanical properties
Pressure measurement
in vivo studies
volunteers
Volume measurement
Healthy Volunteers
Hydration
Surface waves
Pressure
Formaldehyde
Analytical models
Elastic moduli

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Medicine(all)

Cite this

Noninvasive evaluation of bladder wall mechanical properties as a function of filling volume : Potential application in bladder compliance assessment. / Nenadic, Ivan; Mynderse, Lance; Husmann, Douglas; Mehrmohammadi, Mohammad; Bayat, Mahdi; Singh, Aparna; Denis, Max; Urban, Matthew W; Alizad, Azra; Fatemi, Mostafa.

In: PLoS One, Vol. 11, No. 6, e0157818, 01.06.2016.

Research output: Contribution to journalArticle

Nenadic, Ivan ; Mynderse, Lance ; Husmann, Douglas ; Mehrmohammadi, Mohammad ; Bayat, Mahdi ; Singh, Aparna ; Denis, Max ; Urban, Matthew W ; Alizad, Azra ; Fatemi, Mostafa. / Noninvasive evaluation of bladder wall mechanical properties as a function of filling volume : Potential application in bladder compliance assessment. In: PLoS One. 2016 ; Vol. 11, No. 6.
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