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Pomian A, Majkusiak W, Kociszewski J, Tomasik P, Horosz E, Zwierzchowska A, Lisik W, Barcz E. Demographic features of female urethra length. Neurourol Urodyn 2018; 37:1751-1756. [PMID: 29427320 DOI: 10.1002/nau.23509] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 01/04/2018] [Indexed: 11/06/2022]
Abstract
AIMS To determine cohort urethral length, identify epidemiological factors influencing the parameter and to establish the percentage of cases with clinically relevant outsized urethras. METHODS Prospective cohort study conducted in two tertiary clinical centers between 2013 and 2017. Nine hundred and twenty seven consecutive adult, Caucasian females attending outpatients' clinics were included. The urethral length has been measured in pelvic floor ultrasound examination. The exclusion criteria were inadequate bladder filling (<200 mL; >400 mL), previous history of pelvic floor surgery, and no consent. RESULTS Urethral length varied from 19 to 45 mm. The distribution of the examined parameter was normal. Obese patients had significantly longer urethras as compared to non-obese subjects. Number of vaginal deliveries was connected with shorter urethral length. The limitations of the study are: analysis only of Caucasian patients and subjects without previous pelvic floor surgeries. CONCLUSIONS Differences in urethral length in the female population were demonstrated. Thirty percent of patients have atypical urethras that may be a risk factor for sling surgery failure. We therefore postulate introduction of urethral measurement before the procedure.
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Affiliation(s)
- Andrzej Pomian
- Ist Department of Obstetrics and Gynecology, Medical University of Warsaw, Warsaw, Poland
| | - Wojciech Majkusiak
- Ist Department of Obstetrics and Gynecology, Medical University of Warsaw, Warsaw, Poland
| | | | - Paweł Tomasik
- Ist Department of Obstetrics and Gynecology, Medical University of Warsaw, Warsaw, Poland
| | - Edyta Horosz
- Ist Department of Obstetrics and Gynecology, Medical University of Warsaw, Warsaw, Poland
| | - Aneta Zwierzchowska
- Ist Department of Obstetrics and Gynecology, Medical University of Warsaw, Warsaw, Poland
| | - Wojciech Lisik
- Deparment of General Surgery and Transplantology, Medical University of Warsaw, Warsaw, Poland
| | - Ewa Barcz
- Ist Department of Obstetrics and Gynecology, Medical University of Warsaw, Warsaw, Poland
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Maran JC, Cassagnes L, Delmas V, Musset D, Frydman R, Mage G, Canis M, Boyer L, Ami O. Comparative anatomy on 3-D MRI of the urogenital sinus and the periurethral area before and during the second stage of labor during childbirth. Surg Radiol Anat 2017; 40:371-380. [DOI: 10.1007/s00276-017-1925-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 09/13/2017] [Indexed: 01/01/2023]
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Murakami N, Norihisa Y, Isohashi F, Murofushi K, Ariga T, Kato T, Inaba K, Okamoto H, Ito Y, Toita T, Itami J. Proposed definition of the vaginal cuff and paracolpium clinical target volume in postoperative uterine cervical cancer. Pract Radiat Oncol 2016; 6:5-11. [PMID: 26767622 DOI: 10.1016/j.prro.2015.04.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2015] [Revised: 04/15/2015] [Accepted: 04/20/2015] [Indexed: 11/24/2022]
Abstract
PURPOSE The aim of this study was to develop an appropriate definition for vaginal cuff and paracolpium clinical target volume (CTV) for postoperative intensity modulated radiation therapy in patients with uterine cervical cancer. METHODS AND MATERIALS A working subgroup was organized within the Radiation Therapy Study Group of the Japan Clinical Oncology Group to develop a definition for the postoperative vaginal cuff and paracolpium CTV in December 2013. The group consisted of 5 radiation oncologists who specialized in gynecologic oncology and a gynecologic oncologist. A comprehensive literature review that included anatomy, surgery, and imaging fields was performed and was followed by multiple discreet face-to-face discussions and e-mail messages before a final consensus was reached. RESULTS Definitions for the landmark structures in all directions that demarcate the vaginal cuff and paracolpium CTV were decided by consensus agreement of the working group. A table was created that showed boundary structures of the vaginal cuff and paracolpium CTV in each direction. CONCLUSIONS A definition of the postoperative cervical cancer vaginal cuff and paracolpium CTV was developed. It is expected that this definition guideline will serve as a template for future radiation therapy clinical trial protocols, especially protocols involving intensity modulated radiation therapy.
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Affiliation(s)
- Naoya Murakami
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan.
| | - Yoshiki Norihisa
- Department of Radiation Oncology and Image-applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto, Japan; Department of Radiation Therapy, Bell Land General Hospital, Osaka, Japan
| | - Fumiaki Isohashi
- Department of Radiation Oncology, Osaka University Hospital, Osaka, Japan
| | - Keiko Murofushi
- Department of Radiation Oncology, University of Tsukuba, Ibaraki, Japan
| | - Takuro Ariga
- Department of Radiology, Graduate School of Medicine, University of Ryukyus, Okinawa, Japan
| | - Tomoyasu Kato
- Department of Gynecological Oncology, National Cancer Center Hospital, Tokyo, Japan
| | - Koji Inaba
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan
| | - Hiroyuki Okamoto
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan
| | - Yoshinori Ito
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan
| | - Takafumi Toita
- Department of Radiology, Graduate School of Medicine, University of Ryukyus, Okinawa, Japan
| | - Jun Itami
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan
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MRI changes of pelvic floor and pubic bone observed in primiparous women after childbirth by normal vaginal delivery. Arch Gynecol Obstet 2016; 294:285-9. [PMID: 26861464 PMCID: PMC4937070 DOI: 10.1007/s00404-016-4023-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Accepted: 01/15/2016] [Indexed: 11/27/2022]
Abstract
Objective
To identify and characterize changes in the pelvic floor and pubic bone, using magnetic resonance imaging, in primiparous women with normal vaginal delivery, in comparison with nulliparous women.
Methods Pelvic MR images from ten primiparous women, 6–7 weeks after normal vaginal delivery, and ten nulliparous women were obtained from January to April 2014. The selected women were scanned using a multiplanar T2FRFSE sequence and T2fsFRFSE sequence. Changes in the pelvic floor and pubic bone in primiparous women, including tears of the levator ani fibers, pubic bone edema, and fractures, were assessed on the MR images in comparison with images from normal nulliparous women. Injury to the levator ani was evaluated and scored. The incidence, location and the extent of injury to the levator ani and pubic bone were characterized further. Results Eight out of ten primiparous women had imaging abnormalities after normal vaginal delivery. Three women had unilateral tears of the pubococcygeus, in which the defect in the muscle was located at or near its origin at the pubic bone, and one had a pubococcygeus tear accompanied by bilateral spilling of the vagina. Four women had partial tears of the iliococcygeus: one was a bilateral tear, and three were unilateral. None had a tear of the coccygeus. Eight women had pubic bone marrow edema; one was accompanied by a pubic bone fracture line. None of the nulliparous women had any abnormality of the pelvic floor and pubic bone. Conclusion Abnormalities of the pelvic floor and pubic bone were observed in primiparous women but not in nulliparous women. In primiparous women, most levator ani muscle tears are at or near the point of origin, and pubococcygeus injuries are usually accompanied by pubic bone marrow edema.
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Silva M, Oliveira D, Roza T, Brandão S, Parente M, Mascarenhas T, Natal Jorge R. Study on the influence of the fetus head molding on the biomechanical behavior of the pelvic floor muscles, during vaginal delivery. J Biomech 2015; 48:1600-5. [DOI: 10.1016/j.jbiomech.2015.02.032] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 02/15/2015] [Indexed: 11/30/2022]
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LI R, Song Y, Ma M. Relationship between levator ani and bony pelvis morphology and clinical grade of prolapse in women. Clin Anat 2015; 28:813-9. [DOI: 10.1002/ca.22536] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Revised: 02/22/2015] [Accepted: 02/22/2015] [Indexed: 11/09/2022]
Affiliation(s)
- Ran LI
- Department of Obstetrics and Gynecology; Fuzong Clinical College of Fujian Medical University; Fuzhou Fujian 350025 China
| | - Yanfeng Song
- Department of Obstetrics and Gynecology; Fuzong Clinical College of Fujian Medical University; Fuzhou Fujian 350025 China
| | - Ming Ma
- Department of Radiology; Fuzhou General Hospital; Fuzhou Fujian 350025 China
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Akhondi-Asl A, Hoyte L, Lockhart ME, Warfield SK. A logarithmic opinion pool based STAPLE algorithm for the fusion of segmentations with associated reliability weights. IEEE TRANSACTIONS ON MEDICAL IMAGING 2014; 33:1997-2009. [PMID: 24951681 PMCID: PMC4264575 DOI: 10.1109/tmi.2014.2329603] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Pelvic floor dysfunction is common in women after childbirth and precise segmentation of magnetic resonance images (MRI) of the pelvic floor may facilitate diagnosis and treatment of patients. However, because of the complexity of its structures, manual segmentation of the pelvic floor is challenging and suffers from high inter and intra-rater variability of expert raters. Multiple template fusion algorithms are promising segmentation techniques for these types of applications, but they have been limited by imperfections in the alignment of templates to the target, and by template segmentation errors. A number of algorithms sought to improve segmentation performance by combining image intensities and template labels as two independent sources of information, carrying out fusion through local intensity weighted voting schemes. This class of approach is a form of linear opinion pooling, and achieves unsatisfactory performance for this application. We hypothesized that better decision fusion could be achieved by assessing the contribution of each template in comparison to a reference standard segmentation of the target image and developed a novel segmentation algorithm to enable automatic segmentation of MRI of the female pelvic floor. The algorithm achieves high performance by estimating and compensating for both imperfect registration of the templates to the target image and template segmentation inaccuracies. A local image similarity measure is used to infer a local reliability weight, which contributes to the fusion through a novel logarithmic opinion pooling. We evaluated our new algorithm in comparison to nine state-of-the-art segmentation methods and demonstrated our algorithm achieves the highest performance.
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Affiliation(s)
- Alireza Akhondi-Asl
- Computational Radiology Laboratory, Department of Radiology, Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Lennox Hoyte
- Department of Obstetrics and Gynecology, University of South Florida, 2 Tampa General Circle, 6th oor, Tampa, FL 33606, USA
| | - Mark E. Lockhart
- Department of Radiology, University of Alabama at Birmingham, 1802 6th Avenue South, Birmingham, AL 35233, USA
| | - Simon K. Warfield
- Computational Radiology Laboratory, Department of Radiology, Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
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Brandão S, Da Roza T, Parente M, Ramos I, Mascarenhas T, Natal Jorge RM. Magnetic resonance imaging of the pelvic floor: from clinical to biomechanical imaging. Proc Inst Mech Eng H 2013; 227:1324-32. [PMID: 24030164 DOI: 10.1177/0954411913502952] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This article reviews the current role of magnetic resonance imaging in the study of the pelvic floor anatomy and pelvic floor dysfunction. The application of static and dynamic magnetic resonance imaging in the clinical context and for biomechanical simulation modeling is assessed, and the main findings are summarized. Additionally, magnetic resonance-based diffusion tensor imaging is presented as a potential tool to evaluate muscle fiber morphology. In this article, focus is set on pelvic floor muscle damage related to urinary incontinence and pelvic organ prolapse, sometimes as a consequence of vaginal delivery. Modeling applications that evaluate anatomical and physiological properties of pelvic floor are presented to further illustrate their particular characteristics. Finally, finite element method is described as a method for modeling and analyzing pelvic floor structures' biomechanical performance, based on material and behavioral properties of the tissues, and considering pressure loads that mimic real-life conditions such as active contraction or Valsalva maneuver.
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Affiliation(s)
- Sofia Brandão
- Department of Radiology, Centro Hospitalar de São João-EPE, Porto, Portugal
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Lenis AT, Kuang M, Woo LL, Hijaz A, Penn MS, Butler RS, Rackley R, Damaser MS, Wood HM. Impact of parturition on chemokine homing factor expression in the vaginal distention model of stress urinary incontinence. J Urol 2012; 189:1588-94. [PMID: 23022009 DOI: 10.1016/j.juro.2012.09.096] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 09/13/2012] [Indexed: 01/12/2023]
Abstract
PURPOSE Human childbirth simulated by vaginal distention is known to increase the expression of chemokines and receptors involved in stem cell homing and tissue repair. We hypothesized that pregnancy and parturition in rats contributes to the expression of chemokines and receptors after vaginal distention. MATERIALS AND METHODS We used 72 age matched female Lewis rats, including virgin rats with and without vaginal distention, and delivered rats with and without vaginal distention. Each rat was sacrificed immediately, or 3 or 7 days after vaginal distention and/or parturition, and the urethra was harvested. Relative expression of chemokines and receptors was determined by real-time polymerase chain reaction. Mixed models were used with the Bonferroni correction for multiple comparisons. RESULTS Vaginal distention up-regulated urethral expression of CCL7 immediately after injury in virgin and postpartum rats. Hypoxia inducible factor-1α and vascular endothelial growth factor were up-regulated only in virgin rats immediately after vaginal distention. CD191 expression was immediately up-regulated in postpartum rats without vaginal distention compared to virgin rats without vaginal distention. CD195 was up-regulated in virgin rats 3 days after vaginal distention compared to virgin rats without vaginal distention. CD193 and CXCR4 showed delayed up-regulation in virgin rats 7 days after vaginal distention. CXCL12 was up-regulated in virgin rats 3 days after vaginal distention compared to immediately after vaginal distention. Interleukin-8 and CD192 showed no differential expression. CONCLUSIONS Vaginal distention results in up-regulation of the chemokines and receptors expressed during tissue injury, which may facilitate the spontaneous functional recovery previously noted. Pregnancy and delivery up-regulated CD191 and attenuated the expression of hypoxia inducible factor-1α and vascular endothelial growth factor in the setting of vaginal distention, likely by decreasing hypoxia.
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Affiliation(s)
- Andrew T Lenis
- Department of Biomedical Engineering, Cleveland Clinic, Cleveland, Ohio 44195, USA
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Frederice CP, Amaral E, Ferreira NDO. Urinary symptoms and pelvic floor muscle function during the third trimester of pregnancy in nulliparous women. J Obstet Gynaecol Res 2012; 39:188-94. [DOI: 10.1111/j.1447-0756.2012.01962.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Schwertner-Tiepelmann N, Thakar R, Sultan AH, Tunn R. Obstetric levator ani muscle injuries: current status. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2012; 39:372-383. [PMID: 22190408 DOI: 10.1002/uog.11080] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Levator ani muscle (LAM) injuries occur in 13-36% of women who have a vaginal delivery. Although these injuries were first described using magnetic resonance imaging, three-dimensional transperineal and endovaginal ultrasound has emerged as a more readily available and economic alternative to identify LAM morphology. Injury to the LAM is attributed to vaginal delivery resulting in reduced pelvic floor muscle strength, enlargement of the vaginal hiatus and pelvic organ prolapse. There is inconclusive evidence to support an association between LAM injuries and stress urinary incontinence and there seems to be a trend towards the development of fecal incontinence. Longitudinal studies with long-term follow-up assessing the LAM before and after childbirth are lacking. Furthermore, the consequence of LAM injuries on quality of life due to prolapse and/or urinary and fecal incontinence have not been evaluated using validated questionnaires. Direct comparative studies using the above-mentioned imaging modalities are needed to determine the true gold standard for the diagnosis of LAM injuries. This would enable consistency in definition and classification of LAM injuries. Only then could high-risk groups be identified and preventive strategies implemented in obstetric practice.
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Rodrigues AA, Bassaly R, McCullough M, Terwilliger HL, Hart S, Downes K, Hoyte L. Levator ani subtended volume: a novel parameter to evaluate levator ani muscle laxity in pelvic organ prolapse. Am J Obstet Gynecol 2012; 206:244.e1-9. [PMID: 22075059 DOI: 10.1016/j.ajog.2011.10.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2011] [Revised: 08/18/2011] [Accepted: 10/03/2011] [Indexed: 10/16/2022]
Abstract
OBJECTIVE We describe a new parameter based on magnetic resonance 3-dimensional (3D) reconstructions proposed to evaluate levator ani muscle (LAM) laxity in women with pelvic organ prolapse (POP). STUDY DESIGN This is an institutional review board-approved, retrospective chart review of 35 women with POP, stages I-IV. The 3D Slicer software package was used to perform 2-dimensional and 3D measurements and the levator ani subtended volume (LASV) was described. Basically, the LASV represents the volume contained by LAM between 2 planes, which coincides with pubococcygeal line and H line. Correlations among measurements, ordinal POP stages, POP Quantification (POPQ) individual measurements, and validated questionnaires were performed. RESULTS The LASV differentiated major (III and IV) from minor (I and II) POPQ stages, which positively correlated to POP stages and POPQ individual measurements. CONCLUSION The LASV is a promising parameter to evaluate the LAM laxity.
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Ying T, Li Q, Xu L, Liu F, Hu B. Three-dimensional ultrasound appearance of pelvic floor in nulliparous women and pelvic organ prolapse women. Int J Med Sci 2012; 9:894-900. [PMID: 23155363 PMCID: PMC3498754 DOI: 10.7150/ijms.4829] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 10/25/2012] [Indexed: 11/18/2022] Open
Abstract
The present study investigated the morphology and structure of pelvic floor in 50 nulliparous and 50 pelvic organ prolapse (POP) women using translabial three-dimensional (3D) ultrasound. The levator hiatus in POP women was significantly different from that in nullipara women. In POP women, the size of pelvic floor increased, with a circular shape, and the axis of levator hiatus departed from the normal position in 36 (72%) cases. The puborectalis was avulsed in 18 (36%) cases and the pelvic organs arranged abnormally in 23 (46%) cases. In summary, 3D ultrasound is an effective tool to detect the pelvic floor in POP women who presented with abnormalities in the morphology and structure of pelvic floor.
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Affiliation(s)
- Tao Ying
- Department of Ultrasound in Medicine, Shanghai Jiaotong University Affiliated Sixth People's Hospital, People's Republic of China.
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Gregory WT, Nardos R, Worstell T, Thurmond A. Measuring the levator hiatus with axial MRI sequences: adjusting the angle of acquisition. Neurourol Urodyn 2011; 30:113-6. [PMID: 21046654 DOI: 10.1002/nau.20957] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
AIMS We aimed to compare MRI measurements of the female levator hiatus and the most caudal "levator ani" muscles between image slices in a plane axial to the body (AxB) and an axial plane parallel to the direction of the puborectalis muscle (AxPRM). METHODS We performed high-resolution, T2-weighted axial magnetic resonance imaging (in two different planes) on 20 sequentially recruited asymptomatic nulliparous women. Levator hiatus measurements were compared between the two planes. RESULTS The mean tilt angle of the AxPRM slices relative to the AxB slices was 18.9° (SD 8.5) and the area of the levator hiatus was 10% greater (P=0.04) in the AxPRM plane. CONCLUSIONS By rotating the acquisition plane to be parallel to the puborectalis muscle (sometimes called the plane of minimal hiatal dimensions), some of the measurements of the distal and medial pelvic floor muscles (and the hiatus defined by them) are altered. This issue is important because both MRI and 3D ultrasound are increasingly being used to evaluate the pelvic floor hiatus, and its relationship to childbirth injury and pelvic floor disorders. To make meaningful comparisons, it is important that both modalities are measuring the same thing.
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Affiliation(s)
- W Thomas Gregory
- Division of Urogynecology and Reconstructive Pelvic Surgery, Department of Obstetrics and Gynecology, Portland, Oregon 97239, USA.
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Martins PA, Jorge RMN, Ferreia AJ, Saleme CS, Roza T, Parente MM, Pinotti M, Mascarenhas T, Santos A, Santos L, Silva-Filho AL. Vaginal Tissue Properties versus Increased Intra-Abdominal Pressure: A Preliminary Biomechanical Study. Gynecol Obstet Invest 2011; 71:145-50. [DOI: 10.1159/000315160] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2009] [Accepted: 05/05/2010] [Indexed: 11/19/2022]
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da Silva-Filho AL, Martins PALS, Parente MP, Saleme CS, Roza T, Pinotti M, Mascarenhas T, Natal Jorge RM. Translation of biomechanics research to urogynecology. Arch Gynecol Obstet 2010; 282:149-55. [DOI: 10.1007/s00404-010-1396-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2009] [Accepted: 02/08/2010] [Indexed: 02/03/2023]
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Noakes KF, Bissett IP, Pullan AJ, Cheng LK. Anatomically realistic three-dimensional meshes of the pelvic floor & anal canal for finite element analysis. Ann Biomed Eng 2008; 36:1060-71. [PMID: 18317929 DOI: 10.1007/s10439-008-9471-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2007] [Accepted: 02/14/2008] [Indexed: 12/17/2022]
Abstract
Three anatomically realistic meshes, suitable for finite element analysis, of the pelvic floor and anal canal regions have been developed to provide a framework with which to examine the mechanics, via finite element analysis of normal function within the pelvic floor. Two cadaver-based meshes were produced using the Visible Human Project (male and female) cryosection data sets, and a third mesh was produced based on MR image data from a live subject. The Visible Man (VM) mesh included 10 different pelvic structures while the Visible Woman and MRI meshes contained 14 and 13 structures, respectively. Each image set was digitized and then finite element meshes were created using an iterative fitting procedure with smoothing constraints calculated from 'L'-curves. These weights produced accurate geometric meshes of each pelvic structure with average Root Mean Square (RMS) fitting errors of less than 1.15 mm. The Visible Human cadaveric data provided high resolution images, however, the cadaveric meshes lacked the normal dynamic form of living tissue and suffered from artifacts related to postmortem changes. The lower resolution MRI mesh was able to accurately portray structure of the living subject and paves the way for dynamic, functional modeling.
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Affiliation(s)
- Kimberley F Noakes
- Bioengineering Institute, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
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