Purpose To explore the significance of three-dimensional reconstruction of fetus based on MRI scan data. Materials and Methods Three woman (more than 39 weeks' gestation) with a strong wish to have natural childbirth and voluntary to take the examination in Nanfang Hospital of Southern Medical University were recruited in the study. Mimics 10.01 software was used to do three-dimensional reconstruction. Results The fetal surface tissue showed low signal on the two-dimensional images, and amniotic fluid and lung, bladder, cerebrospinal fluid showed high signal. The placenta and uterine wall showed moderate to low signal. Those contributed to the clear boundary between fetal surface and other tissue surround. The three-dimensional fetus models were reconstructed successfully, which clearly demonstrated the main surface features and spatial position of the fetus. The fetal morphology and fetal position could be viewed in various directions. Conclusion Fetus surface can be reconstructed into three-dimensional model based on MRI data set, which has advantage of large visual field and can be observed at arbitrary angle. It provides a new method for morphological analysis and prenatal evaluation for fetal development and growth.

Purpose Full-term fetal weight is closely related to the choice of delivery mode and perinatal mortality rate.Our aim is to explore the feasibility of magnetic resource image (MRI) with three-dimensional reconstruction and volume measurement in estimating fetal weight and its accuracy compared to ultrasound (US) examination.Materials and Methods Analyzed the MRI volume measurement of 61 fetuses delivered within 7 days after M RI and ultrasound examination in our hospital between November 2013 and March 2016 using MRI three-dimensional reconstruction.The fetal weight estimated by MRI was calculated by the equation developed by Baker et al and the US estimation of fetal weight was performed according to Haldlock et al,the MRI and US estimation of fetal weight were compared.Results 60 fetuses were included and qualified MRI three-dimensional reconstruction models,one was excluded because of frequent movement.The MRI estimation of fetal weight and the birth weight correlated significantly (r=0.927,P＜0.05).The MRI estimation of fetal weight had a lower percentage of random error than US (3.4％ vs 5.0％,P＞0.05),as well as mean absolute error [(172+ 114) g vs (227± 171) g,P＜0.05],but a higher percentage of relative error ≤ 10％ than US (95.0％ vs 78.3％,P＜0.05),with an underestimation in 90.0％ fetuses compared with birth-weight.Concision Full-term fetal weight estimation by using MRI with three-dimensional reconstruction and volume measurement is feasible and more accurate than ultrasound,but lower than the actual weight.This method can be applied in estimating fetal weight in the case of ultrasound examination limited.

Objective Comparison of the levator ani muscles in three-dimensional (3D) MRI-based models in women with and without pelvic organ prolapse at rest to analyze the morphological characteristics of levator ani muscles in women with POP. Methods Twenty-five women with POP and 22 women with normal pelvic support were selected from Nanfang Hospital of Southern Medical University. Axial, sagittal, and coronal T2-weighted pelvic magnetic resonance scans were obtained with the women in the supine position.The 3D models were reconstructed from the source images. Morphological changes was compared within the two groups of levator ani muscles, and the 3D models were measured to determine the levator ani muscle volume (LVOL), levator plate angle (LPA), levator hiatus width (LH-W) and length (LH-L), distance between symphysis and levator sling muscle (LSG). Results There were no puborectalis avulsions in control, in POP, 3 cases of avulsions just in left, 3 cases of avulsions just in right, 7 cases in bilateral. The shape of iliococcygeus were all dome-shaped in control, 11 cases were U-shaped and 14 cases were dome-shaped in POP. The shape of levator hiatus were 7 cases of U-shape, 12 cases of V-shape, 3 cases of irregular in control; 5 cases of U-shape, 4 cases of V-shape, 16 cases of irregular in POP. POP versus control: LH-L: (68.0 ± 8.9) versus (61.6 ± 7.2) mm (P<0.05); LH-W: (41.4 ± 3.9) versus (38.0 ± 3.2) mm (P<0.05); LSG-L: (29.6 ± 7.4) versus (24.6 ± 3.7) mm (P<0.05); LSG-R: (28.4 ± 6.8) versus (23.9 ± 3.2) mm (P<0.05); LPA: (51.0 ± 11.3)° versus (40.6 ± 6.3)° (P<0.05); LVOL: (23.7 ± 5.8) versus (24.6 ± 5.0) cm3 (P>0.05). Conclusions It is possible to assess the morphologic changes of levator ani by using 3D MRI models objectively, our 3D data demonstrate larger in LVOL, LPA, LH-W, LH-L, LSG, and the changes in shape. It is helpful to diagnose and assess the specific situation of patients POP in clinic.

OBJECTIVE: To reconstruct a three-dimensional model of female urinary system based on magnetic resonance imaging (MRI) and tomography angiography (CTA) data. METHODS: MRI and CTA datasets were collected from 20 patients in our department in 2018 for reconstructing 3D models of the bladder urethra in resting state using Mimics19.0 software combined with engineering software. The metric parameters of the bladder urethra were analyzed in the reconstructed 3D model. RESULTS: The bladder and urethra were successfully reconstructed using 10 MRI datasets, and the kidney, ureter and bladder were reconstructed using 10 CTA datasets. Using engineering software, we measured a number of cysto-urethral geometric parameters, including the cysto-urethral posterior angle (151.1±17.9°), beta angle (137.3±14.0°), urethral pubic angle (47.8± 12.1°), urethral tilt angle (21.5±7.3°), alpha angle (83.8±13.8°), the posterior pubic space (15.3±3.0 mm), and the urethral striated muscle thickness (2.6±0.6 mm). CONCLUSIONS Three-dimensional reconstruction of the anatomical model of the human urinary system provides a platform for studying the fine anatomy of the female urinary system and allows measurement of multiple parameters to better understand the functional differences of the bladder and urethra in different populations.
Female ; Humans ; Magnetic Resonance Imaging ; Models, Anatomic ; Tomography, X-Ray Computed ; Urethra ; Urinary Bladder

OBJECTIVE: To reconstruct a three-dimensional model of female urinary system based on magnetic resonance imaging (MRI) and tomography angiography (CTA) data. METHODS: MRI and CTA datasets were collected from 20 patients in our department in 2018 for reconstructing 3D models of the bladder urethra in resting state using Mimics19.0 software combined with engineering software. The metric parameters of the bladder urethra were analyzed in the reconstructed 3D model. RESULTS: The bladder and urethra were successfully reconstructed using 10 MRI datasets, and the kidney, ureter and bladder were reconstructed using 10 CTA datasets. Using engineering software, we measured a number of cysto-urethral geometric parameters, including the cysto-urethral posterior angle (151.1±17.9°), beta angle (137.3±14.0°), urethral pubic angle (47.8± 12.1°), urethral tilt angle (21.5±7.3°), alpha angle (83.8±13.8°), the posterior pubic space (15.3±3.0 mm), and the urethral striated muscle thickness (2.6±0.6 mm). CONCLUSIONS Three-dimensional reconstruction of the anatomical model of the human urinary system provides a platform for studying the fine anatomy of the female urinary system and allows measurement of multiple parameters to better understand the functional differences of the bladder and urethra in different populations.
Female ; Humans ; Imaging, Three-Dimensional ; Magnetic Resonance Imaging ; Models, Anatomic ; Muscle, Skeletal ; Tomography, X-Ray Computed ; Urethra ; diagnostic imaging ; Urinary Bladder ; diagnostic imaging