Automatic 3D pelvimetry framework in CT images and its validation.

In the field of spinal pathology, sagittal balance of the spine is usually judged by the spatial structure and morphology of pelvis, which can be represented by pelvic parameters. Pelvic parameters, including pelvic incidence, pelvic tilt and sacral slope, are therefore essential for the diagnosis and treatment of spinal disorders, however, it is a time-consuming and laborious procedure to measure these parameters by traditional methods. In this paper, an automatic measurement framework for pelvic CT images was proposed to calculate three-dimensional (3D) pelvic parameters with the support of deep learning technology. Pelvic images were first preprocessed, and 3D reconstruction was then performed to obtain 3D pelvic model by the Visualization Toolkit. DRINet was trained to segment the femoral head region in the pelvic images, and 3D sphere fitting was performed to locate the femoral heads. In addition, VGG16 was adopted to recognize images containing superior sacral endplate, and the plane growth algorithm was used to fit the plane so that the midpoint and normal vector of the superior sacral endplate could be obtained. Finally, 3D pelvic parameters were automatically calculated, and compared with manual measurements for 15 patients. The proposed framework automatically generated 3D pelvic models, and calculated two-dimensional (2D) and 3D pelvic parameters from continuous CT images. Experiments demonstrated that the framework can greatly speed up the calculation of pelvic parameters, and these parameters are accurate when compared with the manual measurements. In conclusion, the proposed framework demonstrates good performance on automatic pelvimetry measurement by incorporating deep learning technology, and can well replace the traditional methods for pelvic parameter measurement.

Developmental three-dimensional examination of the pelvic cavity of Hamdani crossbred sheep fetuses (Ovis aries) in the last two periods of gestation.

BACKGROUND: Türkiye is a country in the world ranking in terms of sheep breeding. Hamdani crossbred sheep breed is one of the sheep breeds that can adapt to the difficult conditions in our country. In addition, the sentence may be corrected as 'Especially in the southeastern part of the Türkiye, crossbreeding is preferred by breeders to increase the yield characteristics of sheep'. OBJECTIVES: In our study, it was aimed to perform a pelvimetric analysis of Hamdani crossbred sheep fetuses in the second and third trimesters by three-dimensional modelling method. METHODS: For this purpose, a total of 40 second-trimester (10 females, 10 males) and third-trimester (10 females, 10 males) fetuses were used. The pelvises of the fetuses were imaged with CT and 3D models were created. Sixteen pelvimetric measurements were performed from the models. The results obtained were evaluated statistically. RESULTS: The study found statistically significant differences between male and female fetuses in terms of vertical diameter (VD) and foramen obturatum width (FOW) measurement parameters in the second trimester. In the third trimester, there were statistically significant differences between genders in acetabulum (AC) (p < 0.01), medial ischial tuberosities (MIT), and ischiatic arch (IA) (p < 0.05) parameters. As a result of the correlation analysis, it was determined that the pelvis length (PL) measurement parameter was positively correlated with different parameters in varying degrees in both periods, while the IA parameter did not show significant correlations with the other parameter in the last two periods of pregnancy. CONCLUSION: In conclusion, the data obtained will be useful in pelvimetric evaluations of human and animal fetuses, anatomy education, zooarchaeology and taxonomy studies.

X-ray Pelvimetry Has No Impact on the Outcomes of Trial of Labor after Cesarean Delivery: A Retrospective Single-center Study.

Few studies have examined the relationship between pelvic size and the success or failure of trial of labor after cesarean delivery (TOLAC). Here we aimed to determine whether pelvic size and morphological data obtained from radiography contribute to the first successful TOLAC. This retrospective single-center observational study enrolled pregnant women who underwent TOLAC between 2010 and 2021. The results of X-ray pelvimetry data, including obstetric conjugate (OC), transverse diameter of the pelvic inlet (TD), anteroposterior diameter of the pelvic inlet (APD), shape of the pelvic inlet, and other obstetrical clinical data, were compared between the success and failure groups. Seventy-five patients in successful group after excluding 35 patients with previous successful TOLAC, and 21 patients in failure group were eligible. The failure group had a higher rate of previous cesarean sections due to failed labor trials (p = 0.042) and heavier newborns (p = 0.014). OC, TD, and APD on X-ray pelvimetry did not differ significantly between the two groups nor did the shape of the pelvic inlet affect the success rate for TOLAC. The generalized linear model identified a history of failed trials of labor as a significant predictor of failed TOLAC (odds ratio, 0.26; 95% confidence interval 0.071-0.923; p = 0.037), whereas no pelvimetric parameters were found. Pelvic size and morphological findings have no discernible impact on the outcomes of TOLAC. The universal application of X-ray pelvimetry in all women attempting TOLAC may not have significant clinical relevance.

Effects of applying high-pass filtering in pelvimetry with Martius images.

AIM: The aim of this study is to investigate whether the results of pelvimetry using original radiographic Martius images and the same images with high-pass filtering applied ("edge images") would be consistent. METHODS: A total of 30 primagravidas were included in this study. Three obstetricians independently measured the anteroposterior and transverse diameters of the pelvic inlet in the original and the edge images, recording the x- and y-coordinates of the four endpoints. A Wilcoxon signed rank sum test was performed on the coordinate data to evaluate differences between the original and edge images. RESULTS: In the analysis of all coordinate data, statistically significant differences were found in both x- and y-coordinates of the sacral promontory point (SPP). In the y-coordinate of the SPP, a statistically significant difference was found in 9 of 30 pairs of images, and in all 9 the anteroposterior diameter was shorter in the edge images compared to the original images due to the more caudal placement of the SPP. CONCLUSIONS: The coordinates of the SPP on original radiographs and their edge images were not consistent in pelvimetry using Martius images. Our results suggest that improved image contrast will allow obstetricians to better assess pelvic narrowing and cephalopelvic disproportion and even reduce radiographic dose, thereby reducing risks for pregnant women and their fetuses.

Sexual dimorphism of the human fetal pelvis exists at the onset of primary ossification.

Human adolescent and adult skeletons exhibit sexual dimorphism in the pelvis. However, the degree of sexual dimorphism of the human pelvis during prenatal development remains unclear. Here, we performed high-resolution magnetic resonance imaging-assisted pelvimetry on 72 human fetuses (males [M]: females [F], 34:38; 21 sites) with crown-rump lengths (CRL) of 50-225 mm (the onset of primary ossification). We used multiple regression analysis to examine sexual dimorphism with CRL as a covariate. Females exhibit significantly smaller pelvic inlet anteroposterior diameters (least squares mean, [F] 8.4 mm vs. [M] 8.8 mm, P = 0.036), larger subpubic angle ([F] 68.1° vs. [M] 64.0°, P = 0.034), and larger distance between the ischial spines relative to the transverse diameters of the greater pelvis than males. Furthermore, the sacral measurements indicate significant sex-CRL interactions. Our study suggests that sexual dimorphism of the human fetal pelvis is already apparent at the onset of primary ossification.

Simple pelvimetry predicts the pelvic manipulation time in robot-assisted low and ultra-low anterior resection for rectal cancer.

PURPOSE: This study explored the difficulty factors in robot-assisted low and ultra-low anterior resection, focusing on simple measurements of the pelvic anatomy. METHODS: This was a retrospective analysis of the clinical data of 61 patients who underwent robot-assisted low and ultra-low anterior resection for rectal cancer between October 2018 and April 2023. The relationship between the operative time in the pelvic phase and clinicopathological data, especially pelvic anatomical parameters measured on X-ray and computed tomography (CT), was evaluated. The operative time in the pelvic phase was defined as the time between mobilization from the sacral promontory and rectal resection. RESULTS: Robot-assisted low and ultra-low anterior resections were performed in 32 and 29 patients, respectively. The median operative time in the pelvic phase was 126 (range, 31-332) min. A multiple linear regression analysis showed that a short distance from the anal verge to the lower edge of the cancer, a narrow area comprising the iliopectineal line, short anteroposterior and transverse pelvic diameters, and a small angle of the pelvic mesorectum were associated with a prolonged operative time in the pelvic phase. CONCLUSION: Simple pelvic anatomical measurements using abdominal radiography and CT may predict the pelvic manipulation time in robot-assisted surgery for rectal cancer.

A comparative study of two pelvimetry methods: 3D models based on CT and MRI.

INTRODUCTION AND HYPOTHESIS: To compare 3D models based on magnetic resonance imaging (MRI) and 3D models based on computed tomography (CT) in pelvimetry. METHODS: A retrospective analysis of 141 patients who underwent both pelvic 3D MRI and 3D CT pelvimetry for gynecological diseases from December 2009 to October 2020 was performed. The two pelvimetry methods were compared by paired Student's t test, Pearson's correlation coefficient, Bland-Altman analysis and intraclass correlation coefficient (ICC). RESULTS: The differences between methods for each diameter were statistically significant, except for those of the posterior sagittal diameter of the pelvic inlet (t:-0.71, P = 0.5) and the anteroposterior pelvic outlet diameter (t:0.02, P = 0.98). 3D MRI and 3D CT pelvimetry strongly correlated with each other (r: min 0.7, max: 0.96, P < 0.01). The Bland-Altman results indicate that the difference points of each pelvic diameter line greater than 95 % are within the 95 % limits of agreement. The ICC was good to very good for all pelvimetric measurements using either MRI-3D (ICC: 0.64-0.98) or CT-3D (ICC: 0.72-0.98) between the two readers. CONCLUSIONS: 3D MRI and 3D CT pelvimetry have good agreement and reproducibility, indicating that 3D MRI is reliable for pelvimetry.

Using CT-Based Pelvimetry and Visceral Obesity Measurements to Predict Total Mesorectal Excision Quality for Patients Undergoing Rectal Cancer Surgery.

BACKGROUND: A complete total mesorectal excision is the criterion standard in curative rectal cancer surgery. Ensuring quality is challenging in a narrow pelvis, and obesity amplifies technical difficulties. Pelvimetry is the measurement of pelvic dimensions, but its role in gauging preoperatively the difficulty of proctectomy is largely unexplored. OBJECTIVE: To determine pelvic structural factors associated with incomplete total mesorectal excision after curative proctectomy and build a predictive model for total mesorectal excision quality. DESIGN: Retrospective cohort study. SETTING: A quaternary referral center database of patients diagnosed with rectal adenocarcinoma (2009-2017). PATIENTS: Curative-intent proctectomy for rectal adenocarcinoma. INTERVENTIONS: All radiological measurements were obtained from preoperative CT images using validated imaging processing software tools. Completeness of total mesorectal excision was obtained from histology reports. MAIN OUTCOME MEASURES: Ability of radiological pelvimetry and obesity measurements to predict total mesorectal excision quality. RESULTS: Of the 410 cases meeting inclusion criteria, 362 underwent a complete total mesorectal excision (88%). Multivariable regression identified a deeper sacral curve (per 100 mm 2 [OR: 1.14; 95% CI, 1.06-1.23; p < 0.001]) and a greater transverse distance of the pelvic outlet (per 10 mm [OR:1.41, 95% CI, 1.08-1.84; p = 0.012]) to be independently associated with incomplete total mesorectal excision. An increased area of the pelvic inlet (per 10 cm 2 [OR: 0.85; 95% CI, 0.75-0.97; p = 0.02) was associated with a higher rate of complete mesorectal excision. No difference in visceral obesity ratio and visceral obesity (ratio >0.4 vs <0.4) between BMI (<30 vs ≥30) and sex was identified. A model was built to predict mesorectal quality using the following variables: depth of sacral curve, area of pelvic inlet, and transverse distance of the pelvic outlet. LIMITATIONS: Retrospective analysis is not controlled for the choice of surgical approach. CONCLUSIONS: Pelvimetry predicts total mesorectal excision quality in rectal cancer surgery and can alert surgeons preoperatively to cases of unusual difficulty. This predictive model may contribute to treatment strategy and aid in the comparison of outcomes between traditional and novel techniques of total mesorectal excision. See Video Abstract . USO DE MEDICIONES DE PELVIMETRA Y OBESIDAD VISCERAL BASADAS EN TC PARA PREDECIR LA CALIDAD DE TME EN PACIENTES SOMETIDOS A CIRUGA DE CNCER DE RECTO: ANTECEDENTES:Una escisión mesorrectal total y completa es el estándar de oro en la cirugía curativa del cáncer de recto. Garantizar la calidad es un desafío en una pelvis estrecha y la obesidad amplifica las dificultades técnicas. La pelvimetría es la medición de las dimensiones pélvicas, pero su papel para medir la dificultad preoperatoria de la proctectomía está en gran medida inexplorado.OBJETIVO:Determinar los factores estructurales pélvicos asociados con la escisión mesorrectal total incompleta después de una proctectomía curativa y construir un modelo predictivo para la calidad de la escisión mesorrectal total.DISEÑO:Estudio de cohorte retrospectivo.ÁMBITO:Base de datos de un centro de referencia cuaternario de pacientes diagnosticados con adenocarcinoma de recto (2009-2017).PACIENTES:Proctectomía con intención curativa para adenocarcinoma de recto.INTERVENCIONES:Todas las mediciones radiológicas se obtuvieron a partir de imágenes de TC preoperatorias utilizando herramientas de software de procesamiento de imágenes validadas. La integridad de la escisión mesorrectal total se obtuvo a partir de informes histológicos.PRINCIPALES MEDIDAS DE VALORACIÓN:Capacidad de la pelvimetría radiológica y las mediciones de obesidad para predecir la calidad total de la escisión mesorrectal.RESULTADOS:De los 410 casos que cumplieron los criterios de inclusión, 362 tuvieron una escisión mesorrectal total completa (88%). Una regresión multivariable identificó una curva sacra más profunda (por 100 mm2); OR:1,14,[IC95%:1,06-1,23,p<0,001], y mayor distancia transversal de salida pélvica (por 10mm); OR:1,41, [IC 95%:1,08-1,84,p=0,012] como asociación independiente con escisión mesorrectal total incompleta. Un área aumentada de entrada pélvica (por 10 cm2); OR:0,85, [IC95%:0,75-0,97,p=0,02] se asoció con una mayor tasa de escisión mesorrectal completa. No se identificaron diferencias en la proporción de obesidad visceral y la obesidad visceral (proporción>0,4 vs.<0,4) entre el índice de masa corporal (<30 vs.>=30) o el sexo. Se construyó un modelo para predecir la calidad mesorrectal utilizando variables: profundidad de la curva sacra, área de la entrada pélvica y distancia transversal de la salida pélvica.LIMITACIONES:Análisis retrospectivo no controlado por la elección del abordaje quirúrgico.CONCLUSIONES:La pelvimetría predice la calidad de la escisión mesorrectal total en la cirugía del cáncer de recto y puede alertar a los cirujanos preoperatoriamente sobre casos de dificultad inusual. Este modelo predictivo puede contribuir a la estrategia de tratamiento y ayudar en la comparación de resultados entre técnicas tradicionales y novedosas de escisión mesorrectal total. (Traducción- Dr. Ingrid Melo).

The influence of MRI-based pelvimetric measurements in mother's choice of delivery in fetal breech position.

INTRODUCTION: At term, about 3-4% of all singleton pregnancies present as breech. MRI-based pelvimetry is a valuable tool to support selection of adequate candidates for a trial-of-labor in women expecting term breech babies. Shared decision-making is playing an increasingly important role in obstetrics. Since the divergent existing knowledge of breech term delivery needs to be discussed with the pregnant woman, we examined the influence of MRI results on the shared decision-making process in women with term breech presentation. METHODS: Between 08/2021 and 12/2022, anamnestic and clinical parameters were collected from singleton pregnancies expecting term breech babies resulting in birth at the Hanover Medical School. After information, written consent and inclusion, clinical parameters, the course of birth and the maternal and fetal outcome were collected retrospectively. 32 women participated in a postpartum questionnaire study on inquiry. The subsequent acquisition of information and the arguments in the decision-making process were determined. In addition, the sense of security and self-determination was asked both before and during birth. RESULTS: 50% of the respondents had not decided for a mode of delivery before having MRI pelvimetry. After imaging and information, about the own pelvic dimensions and predictors for a successful vaginal birth, 80% of this subgroup decided to give birth vaginally. Over 40% of the collective descripted that they made a decision based on the result of MRI pelvimetry. None of the women felt to be insecure after having talked about the MRI results. The elective cesarean section group and the group of those who delivered vaginally were approximately equally highly satisfied with their feeling of self-determination of the birth mode. Overall, the study population had a very positive birth experience. The group of women who had delivered by elective cesarean showed a wider range in their assessment and appeared to perceive the experience more negative than the group of women who had a vaginal birth or emergency cesarean. Fetal and maternal outcomes did not differ between the groups. DISCUSSION: MRT pelvimetry measurements can be used as a predictor for a successful vaginal breech delivery. The additional information obtained from the MRI measurements can be used in the shared decision-making process to decide more easily on the mode of delivery while improving women's awareness and safety. A balanced education on rare and frequently adverse events of vaginal delivery and cesarean section and patient expectations about labor processes must be taken into account.

Updating of pelvimetry standards in modern obstetrics.

Clinical value of pelvimetry in modern obstetrics practices has never been established and normal values are set since the middle of the twentieth century. The aim of this study was to describe current dimensions of pelvis in a female French Caucasian population. A retrospective, bi-centric observational study was conducted from August 2013 to August 2019 in two French departments of Obstetrics. We included all Caucasian women who had a computed tomography pelvimetry during pregnancy. The primary outcome was the values of the obstetric transverse diameter, obstetric conjugate diameter and bispinous diameter. Five hundred and fifty-one CT pelvimetries were analyzed. The median Obstetric Transverse Diameter (OTD) was 12.41 cm and the 3rd percentile was 11 cm. The median Obstetric Conjugate Diameter (OCD) was 12.2 cm and the 3rd percentile was 10.5 cm. The median Bispinous Diameter (BSD) in our data collection was 10.9 cm and the 3rd percentile was 9.3 cm. A significant correlation coefficient between women's height and OTD, OCD and BSD was found. In our study, the OCD and the BSD have not evolved since the middle of the twentieth century. The obstetric transverse diameter was smaller than the standard currently used.

Pelvic diameter is not associated with positive circumferential resection margin in rectal cancer: retrospective analysis of 78 cases

Objective: To identify if there is an association between pelvic entry and pelvic outlet diameters with increased positive circumferential resection margin (CRM) in rectal cancer. Introduction: Positive CRMin rectalcancerisa majorpredictor forlocal anddistant recurrence. Pelvic diameters may be related to the difficulty of dissection, as well as intrinsic tumor characteristics such as tumor size, location, distance from the anal margin, and T stage, which may compromise the integrity of the mesorectum and circumferential margin involvement. Methods: A retrospective review of the patient's medical records who underwent surgical resection of rectal adenocarcinoma from January 2012 to June 2022 was performed. The patient's preoperative staging, operative characteristics, and histopathologic outcomes were gathered from the medical records. Preoperative MRI scanning was done in all patients. MRI pelvimetry was done by two observers. CRM involvement was recorded as stated in the pathology report. Pelvimetry variables were dichotomized according to their mean values for correlation analysis. The odds ratio (OR) was calculated from a binary logistics regression model to assess the relation between the positive CRM and the independent variables. Results: A total of 78 patients were included in this study. A positive CRM was reported in 10 patients (12.8%). BMI >27.4 + 6.6 (p = 0.02), positive extramural vascular invasion (p = 0.027), positive CRM by MRI scanning (p = 0.004), and anal sphincter involvement (p = 0.03) were associated with positive CRM. Pelvimetry values were not associated with a positive CRM. Conclusion: No association was found between the pelvic diameters measured by MRI pelvimetry with a positive CRM. (AU)

Sex determination in budgerigars using radiographic pelvimetry.

BACKGROUND: The purpose of this study was to assess the pelvimetric values obtained from radiographic pelvis images of budgerigars in terms of sexual dimorphism. The objectives included determining linear osteometric and angle measurements of the pelvis, as well as calculating the length-to-width ratios among different pelvimetric measurements. Additionally, the study aimed to reveal the correlations between age and body weight with both the pelvimetric measurements and ratio measurements in these animals. METHODS: In this study, measurements of linear distance, angle and length-to-width ratios were obtained from ventrodorsal images of the pelvis in a sample of 60 budgerigars, consisting of 30 males and 30 females. Subsequently, the statistical analysis of the obtained measurement values was performed. RESULTS: When analysing the morphometric measurement values based on sex, it was observed that all linear measurements (L1, L2, L3, L4, L5, L6, L7, L8, L9, L10 and L11) were higher in males, whereas the angle measurements (A1, LA2 and RA2) were found to be significantly greater in females (p < 0.05). Additionally, both male and female budgerigars exhibited a greater pre-acetabular length of the ilium compared to the post-acetabular length. Moreover, there were mostly positive significant correlations between age and body weight with the pelvic measurement values in both sexes (p < 0.05). CONCLUSIONS: The obtained biometric measurement values from pelvimetric X-ray images in budgerigars were analysed to assess sexual dimorphism. Furthermore, this study presents fundamental morphometric data that can be valuable for clinical, taxonomic, phylogenetic, ornithological, allometric and characterization studies of budgerigars.

The Anterior Pelvic Index (API) in the Classification of the Female Pelvis and Prediction of Fetopelvic Disproportion / El Índice Pelviano Anterior (API) en la Clasificación de la Pelvis Femenina y Predicción de la Desproporción Fetopélvica

SUMMARY: Measurements of the upper strait of the pelvis can be calculated using the Anterior Pelvic Index. The objective of the study was to determine the external validity and cut-off point of the API, to classify narrow pelvises from normal ones. We selected 214 women from 15 to 55 years old, 171 had vaginal delivery and 43 by caesarean section by feto-pelvic disproportion (FPD) of maternal origin, in whom the API was calculated, of which its mean difference was established with an alpha error of <0.05. Maximum values of sensitivity and specificity, ROC curve and Youden index were determined. The student's t gave a p-value =0.000 of the mean difference between the women who had vaginal delivery and those who had cesarean section by FPD of maternal origin; the value of the area under the ROC curve was 0.758 (CI 95% 0.695 - 0.814) with a p-value=0.0001. Maximum sensitivity was 74.42 % (CI 95%: 58.8 % to 86.5 %) and maximum specificity was 73.10 % (CI 95%: 65.8 % to 79.6 %), produced a Youden index of 0.475 (CI 95% 0.283 - 0.590) which is associated with the 15.44 (CI 95% 14.19 - 15.83) of the API scale. The API is a good tool for predicting women with suspected narrow pelvis and allows its classification into three types of pelvises: an API value of more than 15.83 would indicate pelvis suitable for vaginal delivery; an API value between 14.19 and 15.83 would be suspected of pelvic narrowness; an API value less than 14.19 would confirm a narrow pelvis.

Las medidas del estrecho superior de la pelvis pueden calcularse mediante el Índice Pelviano Anterior. El objetivo del estudio fue determinar la validez externa y el punto de corte del API, para clasificar pelvis estrechas de las normales. Seleccionamos 214 mujeres de 15 a 55 años, 171 tuvieron parto vaginal y 43 mediante cesárea por DFP de origen materno, en quienes se calculó el API, del cual se estableció su diferencia de medias con un error alfa de <0,05. Se determinaron valores máximos de sensibilidad y especificidad, curva ROC e índice de Youden. La t de Student dio un p-valor=0,000 de la diferencia de medias entre las mujeres de tuvieron parto vaginal y las que fueron sometidas a cesárea por DFP de origen materno; el valor del área bajo la curva ROC fue 0,758 (IC 95% 0,695 - 0,814) con un p- valor=0,0001. La máxima sensibilidad (74,42 %. IC 95%: 58,8 % a 86,5 %) y máxima especificidad (73,10 %. IC 95%: 65,8 % a 79,6 %), produjeron un índice de Youden de 0,475 (IC 95% 0,283 - 0,590) el cual está asociado al valor 15,44 (IC 95% 14,19 - 15,83) de la escala del API. El API es una buena herramienta de predicción de mujeres con sospecha de pelvis estrecha y permite su clasificación en tres tipos de pelvis: un valor de API de mas de 15,83 indicaría pelvis aptas para un parto vaginal; un valor de API entre 14,19 y 15,83 se sospecharía de estrechez pélvica; un valor de API menor a 14,19 confirmaría una pelvis estrecha.

Predicting mid-pelvic interspinous distance in women using height and pubic arch angle.

OBJECTIVE: To predict the interspinous distance (ISD) using the relationship between female height and pelvimetric measures on magnetic resonance (MR) images. METHODS: We obtained measurements of the pubic arch angle (PAA), inlet-anteroposterior (AP) distance, mid-pelvis AP distance, outlet-AP distance, ISD, and ischial tuberosity distance using 710 pelvic MR images from nonpregnant reproductive-aged (21-50 years) women from January 2014 to June 2020. Patient height was also assessed from medical records. We determined the formula for predicting ISD using multiple regression analysis. RESULTS: The mean ± standard deviation of the height, PAA, inlet-AP distance, mid-pelvis AP distance, outlet-AP distance, ISD, and ischial tuberosity distance were 160.0 ± 5.5 cm, 87.31 ± 6.6°, 129.7 ± 9.0 mm, 119.7 ± 8.5 mm, 111.71 ± 8.90 mm, 108.88 ± 8.0 mm, and 121.97 ± 11.8 mm, respectively. Two significant regression formulas for predicting ISD were identified as follows: ISD = 0.24973 × height - 0.06724 × inlet-AP distance + 0.12166 × outlet-AP distance + 0.29233 × ischial tuberosity distance + 0.32524 × PAA (P < 0.001, R2 = 0.9973 [adjusted R2 = 0.9973]) and ISD = 0.40935 × height + 0.49761 × PAA (P < 0.001, R2 = 0.9965 [adjusted R2 = 0.9965]). CONCLUSION: ISD is the best predictor of obstructed labor. This study predicted ISD with 99% explanatory power using only the height and PAA. The PAA can be measured by transperineal ultrasound. This formula may successfully predict vaginal delivery or cephalopelvic disproportion.

Obstetric pelvimetry by three-dimensional computed tomography in non-pregnant Japanese women: a retrospective single-center study.

OBJECTIVE: While a basic understanding of pelvic size and typology is still important for obstetricians, pelvic measurement data for Japanese women are very scarce. To our best knowledge, no large-scale pelvimetry studies of Japanese women have been made for the past 50 years. This study aimed to investigate the accurate size, particularly the obstetric conjugate (OC) and transverse diameter of the pelvic inlet (TD), of modern Japanese women, using three-dimensional (3D) computed tomography (CT), and to obtain their reference values. METHODS: This retrospective, single-center observational study enrolled Japanese non-pregnant women aged between 20 and 40 years, who underwent pelvic CT examination from 2016 to 2021. CT was performed for various reasons, including acute abdomen, search for cancer metastases, and follow-up of existing disease. However, no cases were taken for pelvic measurements. Pelvimetry was performed retrospectively using a 3D workstation. The OC was measured on a strict lateral view and the TD was measured on an axial-oblique view. Other clinical data, such as age, height, and weight, were also extracted from the medical charts and analyzed. RESULTS: A total of 1,263 patients were enrolled, with the mean age of 32.7 years (standard deviation [SD] 6.2). The mean height, weight, and body mass index were 158.8 cm (SD 5.8), 54.8 kg (SD 11.7), and 21.7 kg/m2 (SD 4.4), respectively. The mean OC length was 127.0 mm (SD 9.5, 95% confidence interval [CI] 126.5-127.5), while the mean TD length was 126.8 mm (SD 7.5, 95% CI 126.4-127.2). Both values were normally distributed. Height was significantly associated with OC (regression coefficient = 0.75 [95% CI 0.66-0.84], p < .001) and TD (regression coefficient = 0.63 [95% CI 0.56-0.70], p < .001). Age showed a weak but statistically significant positive association with TD (regression coefficient = 0.14 [95% CI 0.07-0.20], p < .001) and OC (regression coefficient = -0.10 [95% CI -0.18 to -0.01], p = .026). CONCLUSION: The 3D CT pelvimetry in 1,263 non-pregnant Japanese women of childbearing age revealed the mean OC and TD of 127.0 mm, and 126.8 mm, which were 11.8 mm and 4.3 mm larger, respectively, than those in the survey in 1972. Our data will be referred to in clinical practice as the standard pelvic measurement values for the Japanese population.

Pelvic inlet area is associated with birth mode.

INTRODUCTION: To determine whether a pelvis is wide enough for spontaneous delivery has long been the subject of obstetric research. A number of variables have been proposed as predictors, all with limited accuracy. In this study, we use a novel three-dimensional (3D) method to measure the female pelvis and assess which pelvic features influence birth mode. We compare the 3D pelvic morphology of women who delivered vaginally, women who had cesarean sections, and nulliparous women. The aim of this study is to identify differences in pelvic morphology between these groups. MATERIAL AND METHODS: This observational study included women aged 50 years and older who underwent a CT scan of the pelvis for any medical indication. We recorded biometric data including height, weight, and age, and obtained the obstetric history. The bony pelvis was extracted from the CT scans and reconstructed in three dimensions. By placing 274 landmarks on each surface model, the pelvises were measured in detail. The pelvic inlet was measured using 32 landmarks. The trial was registered at the German Clinical Trials Register DRKS (DRKS00017690). RESULTS: For this study, 206 women were screened. Exclusion criteria were foreign material in the bony pelvis, unknown birth mode, and exclusively preterm births. Women who had both a vaginal birth and a cesarean section were excluded from the group comparison. We compared the pelvises of 177 women between three groups divided by obstetric history: vaginal births only (n = 118), cesarean sections only (n = 21), and nulliparous women (n = 38). The inlet area was significantly smaller in the cesarean section group (mean = 126.3 cm2 ) compared with the vaginal birth group (mean = 134.9 cm2 , p = 0.002). The nulliparous women were used as a control group: there was no statistically significant difference in pelvic inlet area between the nulliparous and vaginal birth groups. CONCLUSIONS: By placing 274 landmarks on a pelvis reconstructed in 3D, a very precise measurement of the morphology of the pelvis is possible. We identified a significant difference in pelvic inlet area between women with vaginal delivery and those with cesarean section. A unique feature of this study is the method of measurement of the bony pelvis that goes beyond linear distance measurements as used in previous pelvimetric studies.

BMI and pelvimetry help to predict the duration of laparoscopic resection for low and middle rectal cancer.

BACKGROUND: In rectal cancer surgery, recent studies have found associations between clinical factors, especially pelvic parameters, and surgical difficulty; however, their findings are inconsistent because the studies use different criteria. This study aimed to evaluate common clinical factors that influence the operative time for the laparoscopic anterior resection of low and middle rectal cancer. METHODS: Patients who underwent laparoscopic radical resection of low and middle rectal cancer from January 2018 to December 2020 were retrospectively analyzed and classified according to the operative time. Preoperative clinical and magnetic resonance imaging (MRI)-related parameters were collected. Logistic regression analysis was used to identify factors for predicting the operative time. RESULTS: In total, 214 patients with a mean age of 60.3 ± 8.9 years were divided into two groups: the long operative time group (n = 105) and the short operative time group (n = 109). Univariate analysis revealed that the male sex, a higher body mass index (BMI, ≥ 24.0 kg/m2), preoperative treatment, a smaller pelvic inlet (< 11.0 cm), a deeper pelvic depth (≥ 10.7 cm) and a shorter intertuberous distance (< 10.1 cm) were significantly correlated with a longer operative time (P < 0.05). However, only BMI (OR 1.893, 95% CI 1.064-3.367, P = 0.030) and pelvic inlet (OR 0.439, 95% CI 0.240-0.804, P = 0.008) were independent predictors of operative time. Moreover, the rate of anastomotic leakage was higher in the long operative time group (P < 0.05). CONCLUSION: Laparoscopic rectal resection is expected to take longer to perform in patients with a higher BMI or smaller pelvic inlet.

Pelvimetric characteristics in agoutis (Dasyprocta prymnolopha) bred under human care / Características pelvimétricas em cutias (Dasyprocta prymnolopha) criadas sob cuidados humanos

The aim of the study was to establish the pattern of the agouti pelvis by obtaining external and radiographic internal pelvimetric values. Forty-three agouti (Dasyprocta prymnolopha), females and males bred in under human care were used. The parameters measured were the external biiliac diameter; the external biischiatic diameter; right and left external ilioischiatic diameters and radiographic internal measurements (true conjugated, the diagonal conjugated; the vertical, the sacral, sagittal, coxal tuberosity, upper biiliac, lower biiliac, and biischiatic diameter. The inlet pelvic area and the outlet pelvic area were calculated, as well the height/width ratios of the entrance area of the pelvis and the pelvic outlet area were calculated. The mean values for each body measurement of females and males were: weight 1.91kg and 2.04kg, external biiliac diameter 6.32cm and 6.30cm, external biischiatic diameter 4.34cm and 4.28cm, right external ilioischiatic diameter 9.01cm and 9.33cm, left external ilioischiatic diameter 9.13cm and 9.30cm, true conjugated 3.90cm and 3.68cm, diagonal conjugated 7.13cm and 6.91cm, vertical diameter 2.59cm and 2.45cm, sacral diameter 2.63cm and 2.44cm, sagittal diameter 3.30cm and 3.09cm, coxal tuberosity diameter 2.52cm and 2.43cm, upper biiliac diameter 6.28cm and 6.24cm, lower biiliac diameter 2.98cm and 2.58cm, biischiatic diameter 2.60cm and 2.70cm, height/width ratio - vertical/ lower biiliac diameter 0.88cm and 0.95cm, sagital/coxal tuberosity diameter 1.32cm and 1.28cm, inlet pelvic area 82.38cm and 77.83cm and outlet pelvic area 24.76cm and 20.07cm. Agouti are dolichopelvic animals, demonstrating the existence of a discrete sexual dimorphism in adults and low intensity correlations between the external and internal measures studied.

O objetivo deste estudo foi estabelecer o padrão da pelve de cutia, masculina e feminina, por meio da obtenção dos valores médios da pelvimetria externa e interna radiográfica. Foram utilizadas 43 cutias (Dasyprocta prymnolopha), fêmeas e machos criadas sob cuidados humanos. Os parâmetros medidos foram o diâmetro biilíaco externo; o diâmetro biisquiático externo; diâmetros ilioisquiáticos externos direito e esquerdo e medidas internas radiográficas (diâmetros conjugado verdadeiro, diagonal conjugado, vertical, sacral, sagital, tuberosidade coxal, biilíaco superior, biilíaco inferior e diâmetro biisquiático). A área pélvica de entrada e a área pélvica de saída foram calculadas , assim como foram calculadas as razões altura/largura da área de entrada da pelve e da área de saída da pelve. Os valores médios para as medidas das fêmeas e dos machos foram, respectivamente: peso 1,91kg e 2,04kg, diâmetro biilíaco externo 6,32cm e 6,30 cm, diâmetro ilioisquiático externo 4,34cm e 4,28cm, diâmetro ilioisquiático externo direito 9,01cm e 9,33cm, diâmetro ilioisquiático externo esquerdo 9,13cm e 9,30cm, diâmetro conjugado verdadeiro 3,90cm e 3,68cm, diâmetro conjugado diagonal 7,13cm e 6,91cm, diâmetro vertical 2,59cm e 2,45cm, diâmetro sacral 2,63cm e 2,44cm, diâmetro sagital 3,30cm e 3,09cm, tuberosidade coxal diâmetro 2,52cm e 2,43cm, diâmetro biilíaco superior 6,28cm e 6,24cm, diâmetro biilíaco inferior 2,98cm e 2,58cm, diâmetro biisquiático 2,60cm e 2,70cm, relação altura/largura - vertical/diâmetro biilíaco inferior 0,88cm e 0,95cm, diâmetro sagital/coxal tuberosidade 1,32cm e 1,28cm, área pélvica de entrada 82,38cm e 77,83 cm e área pélvica de saída 24,76cm e 20,07cm. As cutias são animais dolicopélvicos, demonstrando a existência de um discreto dimorfismo sexual em adultos e correlações de baixa intensidade entre as medidas externas e internas estudadas.

Analysis of MRI radiomic pelvimetry and correlation with margin status after robotic prostatectomy.

INTRODUCTION: To evaluate the use of preoperative magnetic resonance imaging (MRI) as a predictor of positive margins after radical prostatectomy (RP). This is important as such patients may benefit from postoperative radiotherapy. With the advent of preoperative MRI, we posited that pelvimetry could predict positive margins after RP in patients with less-than ideal pelvic dimensions undergoing robotic-assisted laparoscopic surgery. MATERIALS AND METHODS: After IRB approval, data from patients undergoing RP at our center between 1/1/2018 and 12/31/2019 (n = 314) who had undergone prior prostate MRI imaging (n = 102) were analyzed. All RPs were performed using robotic-assisted laparoscopic technique. Data from the cancer center data warehouse were retrieved, to include postoperative T-stage, gland size, responsible surgeon, PSA, patient body mass index, and surgical margin status. These data were analyzed with corresponding pelvimetry data from 91 preoperative scans with complete data and imaging. RESULTS: On multivariable analysis, pathologic T-stage (p = 0.004), anteroposterior pelvic outlet (p = 0.015) and pelvic depth (length of the pubic symphysis; p = 0.019) were all statistically correlated with positive surgical margins. CONCLUSIONS: With the widespread use of MRI in the initial staging of prostate cancer, automated radiomic analysis could augment the critical data already being accumulated in terms of seminal vesical involvement, extracapsular extension, and suspicious lymph nodes as risk factors for postoperative salvage radiation. Such automated data could help screen patients preoperatively for robotic RP.