MR Pelvimetry Research Articles

MR Pelvimetry for Breech Presentation at Term- Interobserver Reliability, Incidental Findings and Reference Values.

Antepartal MR pelvimetry is used to assess the viability of vaginal breech delivery. We evaluated the reliability of MR pelvimetric measurements as well as incidental findings noted by different clinicians and assessed potential reference values. In this monocentric study, the radiologic database was searched for obstetric MR pelvimetries with singleton breech pregnancies between 1999 and 2016. 99 consecutive MR pelvimetries were included. A structured, independent review was performed by six observers with three clinical experience levels (attending, fellow, junior resident from the departments of radiology and obstetrics). Image analysis entailed the quantitative assessment of conjugata vera (CV) and diameter transversalis (DT), image quality and incidental findings. Obstetric data was retrieved from the obstetric database for reference value assessment. Interobserver agreement was strong throughout (mean intraclass correlation coefficient range: 0.889 - 0.968). The individual measuring biases ranged between 0 - 2 mm, and the average limits of agreement were ± 3 mm. Regarding the mode of delivery, the recommended cesarean section (rCS) group showed significantly smaller CV measurements (CV: 11.37 ± 0.73, p-value < 0.0001) than any other delivery group. No statistical difference in CV between the vaginal delivery and unplanned cesarean section groups was found (p-value 0.902). DT measurements only showed a significant difference between rCS and elective cesarean section (p-value 0.039). 134 incidental findings were noted. Strong interobserver agreement irrespective of the reader's experience level supports MR pelvimetry as a reliable method for identifying women with fetopelvic disproportion in breech presentation. For a comprehensive appraisal of incidental findings, radiologic expertise is vital. · MR pelvimetry is a reliable method irrespective of the reader's experience level.. · Conjugata vera measurements aid in the prepartal viability assessment of vaginal breech delivery.. · Incidental findings are relatively common.. · von Bismarck A, Ertl-Wagner B, Stöcklein S et al. MR Pelvimetry for Breech Presentation at Term- Interobserver Reliability, Incidental Findings and Reference Values. Fortschr Röntgenstr 2019; 191: 424 - 432.

Three-dimensional magnetic resonance pelvimetry: A new technique for evaluating the female pelvis in pregnancy

ObjectiveTo describe three-dimensional (3D) magnetic resonance imaging (MRI) pelvimetry methods and to establish the pelvimetric reference in a large population of Chinese females at term pregnancy. MethodsThree-hundred one pregnant women at term who underwent MRI were included. Three-dimensional pelvic models were reconstructed using Mimics. 10.0 software based on MRI data sets, and measurements of these models were made. Pelvimetric results according to delivery modality were presented. Additionally, the previously described CT 3D pelvimetry method for predicting cephalopelvic disproportion (CPD) was used to validate its accuracy. ResultsTwo hundred ten women underwent vaginal delivery, and 13 underwent caesarean delivery for CPD. 3D modelling of the pelvis of pregnant women was feasible using MR data sets. Pelvimetric parameters in the vaginal delivery group were as follows: transverse diameter, 134.7 mm ± 7.5; obstetric conjugate, 126.9 mm ± 8.3; interspinous distance, 113.4 mm ± 8.2; sagittal midpelvis, 117.8 mm ± 8.1; intertuberous distance, 127.1 mm ± 10.4; sagittal outlet, 110.2 mm ± 8.9, and posterior sagittal outlet, 59.7 mm ± 8.1. According to the previously described CT 3D pelvimetry method for predicting CPD, 67.6% (142/210) of women in the vaginal delivery group were diagnosed with CPD. Conclusion3D MR pelvimetry is a novel method for determining pelvic dimensions at term pregnancy. A prospective trial is needed to establish a useful value for predicting CPD in Chinese females at high risk of CPD.

MR pelvimetry: prognosis for successful vaginal delivery in patients with suspected fetopelvic disproportion or breech presentation at term.

The purpose of this study was to correlate MR pelvimetric pelvic inlet measurements with mode of delivery and neonatal outcome in patients with suspected fetopelvic disproportion or breech presentation. For this retrospective monocentric study, 237 consecutive MR pelvimetry reports (1999-2016) of pregnant women due to either suspected fetopelvic disproportion, pelvic deformation after trauma, or persistent breech presentation were retrieved from the radiologic database and matched with corresponding information from the obstetric database. Of 223 included women, 95 (42.6%) underwent planned cesarean section (pCS) and 128 (57.4%) underwent a trial of vaginal labour (TOL), of whom 93 (72.7%) delivered vaginally. Vaginal delivery was successful in 45 out of 64 (70.3%) cephalic cases and in 48 out of 64 (75.0%) breech cases. We found statistically significant differences in conjugata vera obstetrica (CV) and diameter transversalis (DT) between the groups TOL and pCS (CV: 12.5±1.0 vs 12.1±1.2cm, p value 0.001; DT: 13.3±0.9 vs 12.7±0.9cm, p value <0.001, respectively). However, there was no significant difference between successful VD and cesarean section after TOL (CV: 12.5±0.9 vs 12.3±1.1cm, p value 0.194; DT: 13.4±0.9 vs 13.2±0.9cm, p value 0.358, respectively). In our cohort, MR pelvimetry was a useful tool for prepartal assessment of the female pelvis in the selection of TOL candidates. Yet, it does not seem to yield additional predictive value for women with a previous vaginal delivery.

Détection des disproportions fœtopelviennes par réalité virtuelle : étude de faisabilité à propos de trois cas

Routine daily practice shows that successful vaginal delivery for women with suspected narrow pelvis or large fetus remains possible. We present a computer software for the detection of fetopelvic disproportion based on 3D vectorial reconstructions of the fetal head and maternal pelvis with simulation of head passage through the pelvis for collision detection. Three delivery simulations were generated from MR pelvimetry data in two patients, one with narrow pelvis and the other with macrosomic fetus. Based on the simulation, fetus size in both cases was appropriate for the pelvic size, but delivery simulation for the macrosomic fetus concluded that vaginal delivery was mechanically impossible. Further evaluation of this promising software on a larger patient population is necessary.

Fetal shoulder measurements with MRI.

We studied the ability of MRI to predict fetal shoulder width (FSW). In 30 patients referred for MR pelvimetry, measurement of FSW was performed and compared with caliper measurements at term. We report here the feasibility of a method using axial and coronal MR images oriented to the fetal body axes. Shoulder width by MRI (mean = 12.76 +/- 1.42 cm) correlated significantly with postnatal orthopedic caliper measurements (mean = 12.99 +/- 1.37 cm; r = 0.955, SEE = 4.29 mm, p = 0.00001) and with birth weight (r = 0.63, p = 0.0005). Mean paired differences showed a statistically significant 2.3 +/- 4.2 mm underestimation of FSW by MRI (p = 0.01). This reasonably quick nonionizing technique seems to have the potential for evaluating shoulder dystocia and deserves further evaluation.

MR Pelvimetry — A Practical Alternative

Pelvimetry remains a useful technique as part of the assessment of the term breech pregnancy where vaginal delivery is planned. MR pelvimetry is accurate, well tolerated and shows soft-tissue structures as well as bone. It avoids the potentially carcinogenic effects of ionising radiation and is thought to be completely safe for mother and fetus. A technique of MR pelvimetry is described which uses gradient-echo sequences. This quick, practical method makes minimal inroads into valuable scanning time, and may therefore be considered a potentially cost-effective alternative to conventional pelvimetry.

MR Pelvimetry - A Practical Alternative

MR Pelvimetry - A Practical Alternative

Obstetric pelvimetry using nuclear magnetic resonance tomography (MRI): clinical experiences with 150 patients

Between Oct. 1987 and Oct. 1991 150 patients of the Frauenklinik Freiburg were examined by MR pelvimetry (MRI), 135 of which were "ante partum", i.e. just before delivery. The indications were: earlier operative or strongly protracted delivery, clinical suspicion of disproportion between head and pelvis, or obstetrical "problem pelvis" indicated by manual pelvic examination or ultrasonic foetometry. Previous experimental measurements with a phantom and the comparison with conventional radiograms by Guthmann and Martius of 10 patients in puerperium have shown, that the mean divergence was +/- 2 mm, the maximum divergence 5 mm. The MRI method for pelvimetry "ante partum" or in childbed, proved to be a method of high accuracy and a very good option to judge the pelvic shape, whilst being well accepted by the patients. Furthermore, it allows to determine the foetal BIP (biparietal head-diameter), to judge the pelvic soft-tissue, as well as the visualisation of the birth canal, all without any exposure to radiation. MR pelvimetry is thus part of today's clinical routine. The disadvantages are still the high costs as well as the fact, that only few centres have access to MRI equipment. Nevertheless, the pelvimetry "post partum" can be safely practised radiologically due to the very low radiation exposure.

MR Pelvimetry - A Practical Alternative

MR Pelvimetry - A Practical Alternative

Magnetic resonance imaging in obstetrics and gynecology

Magnetic resonance imaging of the female pelvis permits visualization of soft tissue structure previously unseen with other radiological techniques. The internal architecture of the corpus uterus, cervix and vagina are directly visualized in any plane. Furthermore, the hormonal environment of the female can be indirectly determined via assessment of the MR appearance of the uterus. Similarly, the complex changes which occur during pregnancy, such as cervical effacement and the relationship of internal os, fetal part and placenta, are easily documented. MR pelvimetry enables fast, safe depiction of the birth canal. Finally, the demonstrated fetal anatomy may prove particularly useful in the evaluation of intrauterine growth retardation and anomalies indeterminate by ultrasound.

Pelvimetry by Magnetic Resonance Imaging

STARK, DAVID D.; MCCARTHY, SHIRLEY M.; FILLY, ROY A.; PARER, JULIAN T.; HRICAK, HEDVIG; CALLEN, PETER W. Author Information

Pelvimetry revisited

To describe three-dimensional (3D) magnetic resonance imaging (MRI) pelvimetry methods and to establish the pelvimetric reference in a large population of Chinese females at term pregnancy.Three-hundred one pregnant women at term who underwent MRI were included. Three-dimensional pelvic models were reconstructed using Mimics. 10.0 software based on MRI data sets, and measurements of these models were made. Pelvimetric results according to delivery modality were presented. Additionally, the previously described CT 3D pelvimetry method for predicting cephalopelvic disproportion (CPD) was used to validate its accuracy.Two hundred ten women underwent vaginal delivery, and 13 underwent caesarean delivery for CPD. 3D modelling of the pelvis of pregnant women was feasible using MR data sets. Pelvimetric parameters in the vaginal delivery group were as follows: transverse diameter, 134.7 mm ± 7.5; obstetric conjugate, 126.9 mm ± 8.3; interspinous distance, 113.4 mm ± 8.2; sagittal midpelvis, 117.8 mm ± 8.1; intertuberous distance, 127.1 mm ± 10.4; sagittal outlet, 110.2 mm ± 8.9, and posterior sagittal outlet, 59.7 mm ± 8.1. According to the previously described CT 3D pelvimetry method for predicting CPD, 67.6% (142/210) of women in the vaginal delivery group were diagnosed with CPD.3D MR pelvimetry is a novel method for determining pelvic dimensions at term pregnancy. A prospective trial is needed to establish a useful value for predicting CPD in Chinese females at high risk of CPD.