The Restruction Of The Three Dimensional Pelvic Floor Muscles Based On MRI At Rest In Normal And POP Women

Female pelvic organ prolapse (FPOP), is downward descent of the pelvic organs that results in a protrusion of the vagina, uterus or both, which commonly influences the middle-aged women’s life quality.Pelvic floor muscles, pelvic fascia, ligaments and nerves constitute a complex pelvic support system, which maintain the pelvic organs normal position. The pelvic floor muscles play a major role in the initiative support, while due to its location deep and complexity structure, researchers have long been a lack of understanding of their anatomical relationship, which directly lead to the failure of desition whether the injury and the extent of damage in clinically, they need the help of imaging. MRI allows for assessment of all three compartments of the pelvic floor at rest and strain within a single examination using a high-contrast high temporal resolution technique, which has been widely used in clinical practice to evaluate the structure of the pelvic floor. Although the two-dimensional MRI can display the various components of the pelvic floor muscles in anatomy, and describe their morphometric parameters, it could not intuitive and effectively reflect the pelvic floor muscles originate and insert, shape, adjacent relationship,which is helpful to reconstructive surgery. Some research has reported the operation effect is associated with the widen levator hiatus and the levator ani muscle avulsion, but due to lack of effective assessment of levator ani intuitively in preoperative,, the surgeon just decide surgical approach based on clinical experience, could not predict postoperative efficacy and complications. In addition, because of the angle and the thickness, the measurement error in two-dimensional image even have been up to 16%. Thus, if we have a knowledge of wether the pelvic floor muscles are damaged as well as the location and extent of damage intuitively in preoperative,we could design the surgery advance, and the policy can be carried out according to the actual situation of individual patches.In recent years, the digital three-dimensional technology based on imaging provides a new way for the diagnosis and treatment of disease. Three-dimensional model with the advantages of multi-dimensional, multi-angle observation position,could simulate the patient examination, and can reduce error-dimensional measurement by measure in 3-D models directly. The technology has already been used in the orthopedics, hepatobiliary surgery, cardiac surgery and other clinical specialties, showing good clinical value and application prospect. Using this technique which could transformMRI image data sets into a three-dimensional model, the entire pelvic anatomy could display intuitively, not only take advantage of high-dimensional MRI of soft tissue identification, but also solve the inadequate of two-dimensional image in measurement caused by the layer thickness and angle. Constructing of female pelvic floor muscles can not only provide a vivid anatomical teaching models, but also guidae the individual clinical pelvic reconstructive surgery, besides, it could help clinicians assessing the pelvic floor muscles before surgery, provide an objective scientific basis to assess the efficacy of surgery, postoperative complicationsThe purpose of this study is to use MRI data to build a three-dimensional model of female pelvic, including pelvic floor muscles, pelvic, and pelvic organs (uterus, vagina, bladder, urethra and rectum), and through the analysis of the model and its associated function parameter measurements to assess the situation on the pelvic floor. The research consisted of three parts:The first part is to construct and analyse anatomical characteristics of the pelvic floor in young nulliparous volunteers based on three-dimensional MRI, to explore methods of measurement, getting the young nulliparous’ pelvic parameters; the second part, constructing the models of asymptomatic middle-aged women, analyses the changes resulted by the age, parity vaginal delivery, and body mass index (BMI).the third part, based on the first part of the method, control the age, parity vaginal delivery, and body mass index (BMI), constructing the women without symptoms and women with POP pelvic floor,measure the three-dimensional model to analysis the pelvic floor muscles structural changes in POP.Part one Anatomical characteristics of the pelvic floor muscles in young nulliparous women based on 3-D MRI[Objective]Analyse anatomical characteristics of the pelvic floor in young nuUiparous volunteers based on three-dimensional MRI.[Method]1. Thin slice MR1 was performed in 25 young nulliparous volunteers in Southern Medical University from January 1,2013, to May 20. Participants were excluded if they ever had a prior pelvic operation or had any symptoms of urinary or bowel leakage or pelvic organ prolapse, as identified using ICI-Q-SF questionnaire incontinence and pelvic floor dysfunction PFDI-20 questionnaire. All volunteers undergone pelvic ultrasound to exclude pelvic disease, any woman with a contraindication to MRI was excluded from the study. Acquisite the original DICOM dataes,2. the source images and observaed the following parameters:the shape of vigina, levator hiatus and iliococcygeus. the images were electronically transferred to a sofeware Mimics 10.0 for production of 3D models. The 3D models were reconstructed by a full-experienced junior doctor. The data were first segmented into significant components including bones, bladder, urethra, vagina, uterus, rectum, obturator internus, and the pelvic floor musles using manual editing. We generated three-dimensional surface models from the outlined structures。The 3-D models were exported by STL.3. The 3-dimensional models were measured to determine length of PCL、 bi-ischial diameter、intertuberous diameter,and levator muscle volume(LVOL), levator plate angle(LPA), the width、length of levator hiatus(LH-L、LH-W), Levator symphasis gap (LSG). Import the STL of pelvic organs to UG software,measure the distance from cervix(Cu-PCL, Cd-PCL)、vaginae fornix(VP-PCL, VA-PCL、bladder neck(BN-PCL)、ampulla of rectum (R-PCL)to pubococcygeal line (PCL)。[Results]1. The contruction of female pelvic three-dimensional MRIIn the present study, based on MRI data sets using Mimics software to successfully construct the pelvic three dimensional model, which can be any angle of rotation, size scaling. The pelvis are complete, pelvic organs included the uterus, vagina, bladder, urethra and rectum, anus, we can distinguish the up and down of cervix, the anterior and posterior of vaginae fornix; judging the positional relationship between the organ and the PCL line intuitively. We could observe three levels of the pelvic floor muscles clearly from bottom to top:(1) the perineal muscles, consisted by bulbospongiosus, ischial cavernous muscle, superficial transverse perineal muscle, external anal sphincter composition; (2) the levator ani muscle which subdivision were iliococcygeus, puborectalis, and pubococcygeus which include pubovaginalis, puboperineal, puboanal; (3) ischiococcygeus.2. The characteristics of the pelvic floor muscles in young nulliparous womenIn the source images, all women had H-shaped vaginas, and no one was asymmetry. All the shape of iliococcygeus were dome-shaped, the levator hiatus were all V-shaped. And there were no avulsion in the origin of puborectalisThe pelvis reference line:PCL:100.97±7.79mm; bi-ischial diameter: 108.01±8.36mm; intertuberous diameter:123.90±8.57mm;The cervix, vaginae fornix, bladder neck, ampulla of rectum were above the PCL,distance from them to pubococcygeal line (PCL):VP-PCL:21.77±6.06mm; VA-PCL:25.36±4.08mm; Cu-PCL:33.77±5.74 mm; Cd-PCL:18.94±4.91mm; BN-PCL:11.65±3.51mm; R-PCL:3.48±4.66mm.The levator ani three-dimensional parameters:LVOL:33.91±6.28cm3,LPA:42.9 4± 4.38°,LH-W:32.58 ± 4.09mm, LH-L:54.03±5.09mm, LSG-L:18.79±2.52mm, LSG-R:18.24±2.50mm;[Conclusion]It is an effective way to use the computer to reconstruct the 3D model of female pelvic floor muscles using MR1 data set. The quantitative analysis of levator ani muscle three-dimensional model can be assessed pelvic floor function, which is of great value in clinical practice. It is helpful to understand the pelvic floor disorders pathogenesis, clinical diagnosis, treatment options and treatment evaluation to provide reference standards.Part two Anatomical characteristics of the pelvic floor muscles in asymptomatic middle-aged women based on 3-D MRI[Objective]Analyse anatomical characteristics of the pelvic floor in asymptomatic middle-aged women based on three-dimensional MRI.[Method]1. Thin slice MRI was performed in 28 asymptomatic middle-aged women in Southern Medical University from 2012.09 to 2015.01, who came for the diseases not POP,participants were all vaginal delivery, no forceps delivery,no history of pelvic huge mass and huge fibyoids, excluded if they ever had a prior pelvic operation or had any symptoms of urinary or bowel leakage or pelvic organ prolapse, as identified using ICI-Q-SF questionnaire incontinence and pelvic floor dysfunction PFDI-20 questionnaire. All volunteers undergone pelvic ultrasound to exclude pelvic disease, any woman with a contraindication to MRI was excluded from the study. Acquisite the original DICOM dataes,2. the source images and observaed the following parameters:the shape of vigina, levator hiatus and iliococcygeus. the images were electronically transferred to a sofeware Mimics 10.0 for production of 3D models. The 3D models were reconstructed by a full-experienced junior doctor. The data were first segmented into significant components including bones, bladder, urethra, vagina, uterus, rectum, obturator internus, and the pelvic floor musles using manual editing. We generated three-dimensional surface models from the outlined structures。The 3-D models were exported by STL.3. The 3-dimensional models were measured to determine length of PCL、 bi-ischial diameter、intertuberous diameter,and levator muscle volume(LVOL), levator plate angle(LPA), the width、length of levator hiatus(LH-L、LH-W), Levator symphasis gap (LSG). Import the STL of pelvic organs to UG software,measure the distance from cervix(Cu-PCL, Cd-PCL)、vaginae fornix(VP-PCL, VA-PCL)、bladder neck(BN-PCL)、ampulla of rectum (R-PCL)to pubococcygeal line (PCL).4. contrast to the young nulliparous women, analyses the anatomical characteristics of the pelvic floor in asymptomatic middle-aged women.[Results]1. The age, BMI, parity vaginal delivery were statistically significant difference between the two groups.2. The characteristics of the pelvic floor muscles in asymptomatic middle-aged women.(1) the source inamges:the vaginal shape:there were7 cases of H-shaped,13w-shaped,5 一-shaped,3 irregular which showed the viginal wall bulging to the pelvic wall.the shape of iliococcygeus the cases were all dome-shaped.the shape of levator hiatus there were 2cases of U-shape,23 cases of V-shape,2 cases of O-shape,1 cases of irregular.the origin of puborectalis There were no puborectalis avulsions in all cases.(2) the reference line in three modelsThe pelvis reference line:PCL:102.39±6.88mm; IS:108.51±8.00mm; IT:121.50±8.57mm。there were no statistically significant difference between the two groups.The positional relationship between the pelvic organs and PCL:the cervix,the vaginae fornix and the bladder neck were all above the PCL, the ampulla of rectum were all bolow the PCL. The distance from the pelvic organs to PCL: Cu-PCL: 34.18±6.84mm; Cd-PCL: 15.53±7.43mm; VP-PCL: 21.20±7.23mm; VA-PCL: 21.17±5.54mm; BN-PCL: 8.85±5.14mm; R-PCL: -9.13±4.13mm.The Cu、VP were no change, there were all statistically significant except the Cd, contrasting to the young nulliparous womenThe levator ani parameters: LVOL 24.03±5.99cm3, LPA40.69±6.82, LH-W 37.93±3.41mm, LH-L 60.58±7.27mm, LSG-L 24.88±3.63mm, LSG-R 24.09±3.37mm. Contrast to the young nulliparous women, the LH-W、LH-H、LSG were larger, LVOL was smaller, P>0.05; LPA was larger, P<0.05[Conclusion]1. MRI combined with three-dimensional model could assess the structrue and changes of asymptomatic middle-aged women.2. Contrast to the young nulliparous women,affected by increased age,vaginal delivery and increased BMI, the asymptomatic middle-aged women had changed, the Cu、VP were no change, the Cd、BN、VA moved down, while they were all above the PCL, the R moved to below the PCL. The shape of vagina and levator hiatus had changed, the levator hiatus enlarged, the puborectalis moved to dorsal in the larger LSG, but there were no avulsion, LPA larger and LVOL smaller.Part three Anatomical characteristics of the pelvic floor muscles in pelvic organ prolapse women based on 3-D MRI[Objective]Analyse anatomical characteristics of the pelvic floor in pelvic organ prolapse wome middle-aged women based on three-dimensional MRI. [Method]1.31 women with prolapse were selected from Nanfang Hospital from 2012.09 to 2015.-05. were all vaginal delivery, no forceps delivery,no history of pelvic huge mass and huge fibyoids. Axial, sagittal, and coronal T2-weighted pelvic magnetic resonance scans were obtained with the women in the supine position. Participants were excluded if they ever had a prior pelvic operation.2. the source images and observaed the following parameters:the shape of vigina, levator hiatus and iliococcygeus. the images were electronically transferred to a sofeware Mimics 10.0 for production of 3-D models. The 3-D models were reconstructed by a full-experienced junior doctor. The data were first segmented into significant components including bones, bladder, urethra, vagina, uterus, rectum, obturator internus, and the pelvic floor musles using manual editing. We generated three-dimensional surface models from the outlined structures 0 The 3-D models were exported by STL.3. The 3-D models were measured to determine length of PCL、bi-ischial diameter、intertuberous diameter,and levator muscle volume(LVOL), levator plate angle(LPA), the widths length of levator hiatus(LH-L、LH-W), Levator symphasis gap (LSG). Import the STL of pelvic organs to UG software,measure the distance from cervix(Cu-PCL, Cd-PCL). vaginae fornix(VP-PCL, VA-PCL), bladder neck(BN-PCL)> ampulla of rectum (R-PCL)to pubococcygeal line (PCL)4. contrast to the young nulliparous women and the asymptomatic middle-aged women, analyses the anatomical characteristics of the POP women; contrast to the different stage in POP.[Results]1. The age, BMI, parity vaginal delivery were no statistically significant difference between POP and asymptomatic, while statistically significant difference to the young young nulliparous women; there were no statistically significant difference among different stages.2. The characteristics of the pelvic floor muscles in POP women.(1) the source inamges:the vaginal shape:5 cases of (?)-shaped,while 1 case in stage I,3 cases in stage Ⅱ,5 cases in stage Ⅲ; 9 cases--shaped, while 1 case in stage 1,3 cases in stage Ⅱ,1 case in stage IV 17 casas irregular which had 6 showed viginal wall bulging to the pelvic wall and 11 showed unidentified morphology, while 2 cases in stage I,8 cases in stage Ⅱ,5 cases in stage Ⅲ,2 cases in stage IVthe shape of levator hiatus:10 cases of U-shape, while 1 case in stage I,5 cases in stage Ⅱ,3 cases in stage Ⅲ,4 cases in stage IV 17 cases of O-shape, while 3 cases in stage I,4 cases in stage Ⅱ,8 cases in stage Ⅲ,2 cases in stage IV. 4 cases of irregular in POP, while 1 case in stage Ⅱ, 3 cases in stage Ⅲ.the shape of iliococcygeus:17 cases were dome-shaped,while 1 case in stage Ⅰ,11 cases in stage Ⅱ,5 cases in stage Ⅲ. 14 cases were U-shaped, while 3 cases in stage I,3 cases in stage Ⅱ,5 cases in stage Ⅲ,3 cases in stage IVthe origin of puborectalis:7 cases of avulsions in left,3 cases in stage I,9 cases in stage Ⅱ,6 cases in stage Ⅲ,1 case in stage Ⅳ4 cases of avulsions in right,2 cases in stage I,9 cases in stage Ⅱ,4 cases in stage Ⅲ,1 case in stage Ⅳ12 cases of avulsions in bilateral,2 cases in stage I,6 cases in stage Ⅱ,3 cases in stage Ⅲ,1 case in stage IVall above the shape,there were statistically significant difference between POP and asymptomatic,while there were no statistically significant difference among different stages.(2) the reference lines in three models1) The pelvis reference line PCL:107.92±6.68 mm; IS:110.74±8.40mm; IT: 123.20±9.61 mm.The PCL and IS in POP were larger than nulliparous and asymptomatic, while just the PCL had statistically significant difference; while there were no statistically significant difference among different stages.2) The positional relationship between the pelvic organs and PCL:the posterior vaginae fornix, the up of cervix were all above the PCL, there were 3 cases (3/31) of anterior vaginae fornix,10 cases (10/31) of the up of cervix,12cases (12/31) of bladder neck were below the PCL, the ampulla of rectum were all below the PCL.The distance from the pelvic organs to PCL:Cu-PCL:29.63±9.09 mm; Cd-PCL: 1.99±16.43 mm; VP-PCL:16.47±10.34 mm; VA-PCL:14.44±11.02 mm; BN-PCL: 1.71±6.02mm; R-PCL:-14.28±7.76 mm.The distance from the pelvic organs to PCL in POP were less than the other two groups, the Cu-PCL,VA-PCL,BN-PCL,R-PCL were statistically significant. while there were no statistically significant difference among different stages.3) The levator ani parameters:LVOL 23.45±5.98cm3, LPA 50.01±11.64°, LH-W 41.40±4.14mm, LH-L67.89±9.03mm, LSG-L29.38±7.25mm, LSG-R28.29±6.50mm.Contrast to the young nulliparous women, the LH-W\LH-H、LSG were larger, LVOL was smaller, LPA was larger P>0.05;Contrast to the asymptomatic, the LH-W、LH-H、LSG were larger, LPA was larger P>0.05; LVOL was no change.There were no statistically significant difference among different stages[Conclusion]1. Three-dimensional structure of the pelvic floor at rest can be objective assessment of the changes in the structure of POP patients, the levator ani muscle and organ location parameter are an important indicator to evaluate pelvic floor function,and be helpful for diagnosis in clinic.2. Contrast to the young nulliparous women, the POP women had obviously viganal、iliococcygeus、levator hiatus shape change, the origin of puborectalis displayed avulsions; the pelvic organs moved down, the levator hiatus enlarged, the puborectalis moved to dorsal in the larger LSG, LPA larger and LVOL smaller.3. Contrast to the asymptomatic, changes are the same to young nulliparous women,while the extent is relatively small.4. POP patients in the supine under MRI examination while recovered prolapsed organs, the three-dimensional model could not reflect the changes among different degrees.