MR-Based Three-Dimensional Modeling of the Normal Pelvic Floor in  Women

Fielding, Julia R.; Dumanlı, Hüseyin; Schreyer, A.; Okuda, Shigeo; Gering, David T.; Zou, Kelly H.; Kikinis, Ron; Jólesz, Ferenc A.

doi:10.2214/ajr.174.3.1740657

Cited by 143 publications

(101 citation statements)

References 18 publications

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“…17,18 The ability of MRI to allow study of the entire muscle in both two-dimensional and threedimensional displays in living women has obvious advantages for scientific study. 2,19,20 It also allows the ethical study of normal volunteers with proven continence and pelvic organ support. With the significant asymmetries of muscle damage seen, MRI avoids the problems stemming from taking a single biopsy from one side of an individual, which might indicate a healthy muscle there but would fail to pick up that the muscle on the other side is abnormal.…”

Section: Discussionmentioning

confidence: 99%

The appearance of levator ani muscle abnormalities in magnetic resonance images after vaginal delivery

DeLancey

Kearney

Chou

et al. 2003

Obstetrics & Gynecology

388

203

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OBJECTIVE-To describe the appearance and occurrence of abnormalities in the levator ani muscle seen on magnetic resonance imaging (MRI) in nulliparous women and in women after their first vaginal birth.METHODS-Multiplanar proton density magnetic resonance images were obtained at 0.5-cm intervals from 80 nulliparous and 160 vaginally primiparous women. These had been previously obtained in a study of stress incontinence, and half the primiparas had stress incontinence. All scans were reviewed independently by at least two examiners blinded to parity and continence status. RESULTS-Nolevator ani defects were identified in nulliparous women. Thirty-two primiparous women (20%) had a visible defect in the levator ani muscle. Defects were identified in the pubovisceral portion of the levator ani in 29 women and in the iliococcygeal portion in three women. Within the pubovisceral muscle, both unilateral and bilateral defects were found. The extent of abnormality varied from one individual to the next. Of the 32 women with defects, 23 (71%) were in the stress incontinent group.CONCLUSION-Abnormalities in the levator ani muscle are present on MRI after a vaginal delivery but are not found in nulliparas.During a study of the role of vaginal birth in causing urinary incontinence we obtained magnetic resonance images of women with stress incontinence after their first vaginal birth and of normal continent nulliparous and primiparous controls. On evaluating these scans we found abnormalities in the levator ani muscles in both the continent and incontinent women. The abnormalities seemed to occur only in women who delivered vaginally, and not in nulliparas. These abnormalities involved both the pubovisceral and iliococcygeal portions of the muscle and were sometimes unilateral and sometimes bilateral. Here we describe these defects and evaluate whether or not they are associated with vaginal delivery. MATERIALS AND METHODSMagnetic resonance images of the pelvis were obtained from 240 women as part of an institutional review board-approved study concerning vaginal delivery and stress urinary incontinence. Multiplanar two-dimensional fast spin (echo time 15 ms, repetition time 4000 ms) proton density magnetic resonance images of all pelves were obtained by use of a 1.5-tesla superconducting magnet (Signa; General Electric Medical Systems, Milwaukee, WI) with version 5.4 software as previously described. 1 Images 5 mm apart were obtained in axial, coronal, and sagittal views.

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Section: Discussionmentioning

confidence: 99%

The appearance of levator ani muscle abnormalities in magnetic resonance images after vaginal delivery

DeLancey

Kearney

Chou

et al. 2003

Obstetrics & Gynecology

388

203

View full text Add to dashboard Cite

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“…It has been suggested that this measure is beneficial in the assessment in healthy women and in those with SUI, prolapse, and other forms of pelvic floor dysfunction. [17][18][19] 3D imaging provides the most precise representation of the relationships between pelvic floor structures and, hence, is of particular value for surgical planning. 19 Previous studies have reported 3D reconstruction applied to quantify diminished levator ani muscle mass in patients with pelvic floor dysfunction.…”

Section: D Mri Pelvic Reconstructionmentioning

confidence: 99%

“…[17][18][19] 3D imaging provides the most precise representation of the relationships between pelvic floor structures and, hence, is of particular value for surgical planning. 19 Previous studies have reported 3D reconstruction applied to quantify diminished levator ani muscle mass in patients with pelvic floor dysfunction. 20 In other areas of urology, image-based 3D reconstruction has proved helpful as a research technique for centralizing and measuring the volume of tumours in the kidneys and bladder; 19,[21][22][23] however, the use of 3D reconstruction, as with other advanced techniques, requires the use of a defined and reproducible protocol and a method for measuring the 3D renderings.…”

Section: D Mri Pelvic Reconstructionmentioning

confidence: 99%

“…When such imaging becomes available it will extend our basic science knowledge related to muscle morphology, bulk, and signal intensity and likely improve allocation of appropriate treatment. 19 The role of MRI in the assessment of patients with urinary incontinence is anticipated to grow in importance in the future. 26 The ability of MRI to allow study of the entire muscle in both two and three dimensions is a clear advantage for scientific research.…”

Section: A B Cmentioning

confidence: 99%

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Advances in basic science methodologies for clinical diagnosis in female stress urinary incontinence

Abdulaziz

Deegan

Kavanagh

et al. 2017

CUAJ

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We provide an overview of advanced imaging techniques currently being explored to gain greater understanding of the complexity of stress urinary incontinence (SUI) through better definition of structural anatomic data. Two methods of imaging and analysis are detailed for SUI with or without prolapse: 1) open magnetic resonance imaging (MRI) with or without the use of reference lines; and 2) 3D reconstruction of the pelvis using MRI. An additional innovative method of assessment includes the use of near infrared spectroscopy (NIRS), which uses non-invasive photonics in a vaginal speculum to objectively evaluate pelvic floor muscle (PFM) function as it relates to SUI pathology. Advantages and disadvantages of these techniques are described. The recent innovation of open-configuration magnetic resonance imaging (MRO) allows images to be captured in sitting and standing positions, which better simulates states that correlate with urinary leakage and can be further enhanced with 3D reconstruction. By detecting direct changes in oxygenated muscle tissue, the NIRS vaginal speculum is able to provide insight into how the oxidative capacity of the PFM influences SUI. The small number of units able to provide patient evaluation using these techniques and their cost and relative complexity are major considerations, but if such imaging can optimize diagnosis, treatment allocation, and selection for surgery enhanced imaging techniques may prove to be a worthwhile and cost-effective strategy for assessing and treating SUI. IntroductionAdvances in the diagnosis and treatment of female stress urinary incontinence (SUI) are being aided by the use of emerging technologies that offer greater understanding of the basic science underlying bladder disease.1 This is relevant given that female SUI affects 32-64% 2 of the female population and that 11.1% will need to undergo treatment or require surgery in their lifetime.3 In addition to providing novel insights on the causal etiology, new technologies offer elements able to enhance diagnosis and tools relevant to optimizing therapy for a large number of women worldwide. 4Pregnancy and childbirth are the important causes of pelvic floor injury. Subpopulations of patients are recognized within the spectrum of SUI. SUI can be observed in nulliparous women 4.7% of the time. 4 During pregnancy SUI is reported in up to 50% of women, and additional insults to the pelvic floor are known to occur during labour and delivery. 5Epidemiological studies have identified elements related to labour and delivery that influence the frequency of symptoms; however, it is still unclear how much pregnancy contributes to the pathology, whether the predominant effects occur during labour and delivery, and what is the relevance of other risk factors, e.g., maternal age, body weight, genetics, and lifestyle. 4 Currently, it is believed that partial denervation of the pelvic floor and lineal injury to pelvic floor muscles and connective tissue are caused by mechanical and hormonal changes during pregnancy...

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“…Visual comparison gave evidence of the continuum in levator volume degradation, loss of sling integrity and laxity in the order of asymptomatic, genuine stress incontinence and prolapse. It has also been identified that the volume of the levator ani was an indication of pelvic floor dysfunction [4]. Parallel work in other research centres have investigated the differences in the pelvic floors of younger and older women with 3D reconstruction [5], with results suggesting that the 3D models allowed for the location of pelvic floor damage.…”

Section: Introductionmentioning

confidence: 99%

Optimal Scan Planning with Statistical Shape Modelling of the Levator Ani

Su-Lin

Horkaew

Darzi

et al. 2003

Lecture Notes in Computer Science

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Abstract. Defective pelvic organ support is one of the most common problems in women and its intervention requires an accurate preoperative identification of prolapsed organs and their mechanical properties. With the current state-of-theart in magnetic resonance imaging, 3D dynamic imaging of the pelvic floor is prohibited by the maximal temporal resolution that can be achieved. In this paper, we propose an optimal scan-planning approach based on statistical shape modelling of the levators such that only a limited number of 2D imaging planes are needed to recover the entire 3D structure. The statistical shape model was achieved by the use of harmonic shape embedding and modelling whilst the reconstruction of the 3D structure from selected imaging planes was carried out by the incorporation of a conjunct MDL measure indicating the statistical shape variation captured by respective imaging planes. The value of the proposed technique was demonstrated with data acquired from a group of 11 asymptomatic subjects, highlighting the value of the method in studying dynamic shape changes when complete 3D imaging is impractical.

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MR-Based Three-Dimensional Modeling of the Normal Pelvic Floor in Women

Abstract: Muscle morphology, signal intensity, and volume is relatively uniform among healthy young women.

Cited by 143 publications

References 18 publications

The appearance of levator ani muscle abnormalities in magnetic resonance images after vaginal delivery

The appearance of levator ani muscle abnormalities in magnetic resonance images after vaginal delivery

Advances in basic science methodologies for clinical diagnosis in female stress urinary incontinence

Optimal Scan Planning with Statistical Shape Modelling of the Levator Ani

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