ISMRM 24th Annual Meeting & Exhibition • 07-13 May 2016 • Singapore

Scientific Session: Female Pelvis/Fetal

Thursday, May 12, 2016
Summit 2
13:30 - 15:30
Moderator: P. Ellen Grant

Magnetic Resonance Imaging quantification of venous return in pregnant women: A comparison between supine and left lateral tilt position.
Emer J Hughes1, Anthony N Price2, Laura McCabe1, Kelly Pegoretti Baruteau1, Jana Hutter2, Olivia Carney1, Andreia S Gaspar2, Joseph V Hajnal2, and Mary Rutherford1
1Perinatal Imaging and Health, Kings College London, London, United Kingdom, 2Biomedical Engineering, Kings College London, London, United Kingdom
In-vivo imaging of the fetus is commonly undertaken in the left-lateral position to prevent compression of the inferior vena cava (IVC) and hence a vasovagal episode. Studies have shown that the IVC has collateral pathways, such as the lumbar venous plexus and the lumbar veins that provide collateral venous return. Here, we use phase contrast imaging to assess the venous return pathways in pregnant women lying supine and left lateral tilt in the MRI scanner. We found that the spinal venous plexus and the ascending lumbar veins act as a complimentary venous return system to maintain vascular homeostasis in pregnant women lying supine. This supports the proposition that it is feasible to scan pregnant women safely in the supine position. 

In vivo localization and timing of oxygen delivery in human placenta based on BOLD MRI
Jie Luo1,2, Esra Abaci Turk1,2, Polina Golland3,4, Borjan Gagoski1, Carolina Bibbo5, Drucilla J Roberts6, Norberto Malpica7, Julian N Robinson5, Patricia Ellen Grant1, and Elfar Adalsteinsson2,3,8
1Fetal-Neonatal Neuroimaging & Developmental Science Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States, 2Madrid-MIT M+Vision Consortium in RLE, Massachusetts Institute of Technology, Cambridge, MA, United States, 3Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States, 4Computer Science and Artificial Intelligence Laboratory (CSAIL), Massachusetts Institute of Technology, Cambridge, MA, United States, 5Maternal and Fetal Medicine, Brigham and Women's Hospital, Boston, MA, United States,6Obstetric and Perinatal Pathology, Massachusetts General Hospital, Boston, MA, United States, 7Medical Image Analysis and Biometry Laboratory, Universidad Rey Juan Carlos, Madrid, Spain, 8Harvard- MIT Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, United States
Clinically there is no direct measurement of oxygen delivery in placenta. In this study, we propose a method to map the timing of oxygen delivery in the human placenta in vivo. Healthy placentae show p?????n? that agree with normal perfusion timing in response to maternal hyperoxygenation. Pathological placentas exhibit a more dispersed timing across the placenta. Better understanding of the timing in different type of pathology may be achieved by spatial correlation between placental pathology and in vivo placenta images in both healthy and pathological placenta based on BOLD signal change in response to maternal hyperoxygenation.

Placental vascularization quantification using ex-vivo magnetic resonance angiography
Bailiang Chen1,2,3, Jie Duan2,3,4, Jacques Felblinger1,2,3,5, Olivier Morel2,3,4, and Marine Beaumont 1,3,5
1CHRU Nancy, CIC-IT 1433, Inserm, Vandoeuvre-lès-Nancy, France, 2Imagerie Adaptative Diagnostique et Interventionnelle, Université de Lorraine, Nancy, France, 3U947, Inserm, Nancy, France, 4Service d’obstétrique et médecine fœtale, Pôle de Gynécologie-Obstétrique, CHRU Nancy, Nancy, France, 5Pôle S2R, CHRU Nancy, Nancy, France
Abnormal uteroplacental vascurlarization can cause major obstetric complications such as  intra-uterine growth restriction or abnormally invasive placenta. Clinical 3D ultrasound imaging cannot discriminate maternal and fetal flow in utero-placental unit, thus blocking a better understanding of the pathology. Conventional ex-vivo vascularization quantification relies on 2D histological slices using samples dissected from placenta. Micro-CT was applied to fixed small animal placenta but with complicated and long preparation. Here we presented the flexibility of a comprehensive 3D vascularization characterization of a fresh healthy human placenta using ex-vivo MRA. A quantification framework is proposed with defined systematic metrics to characterize the vascularization.

MRI Quantification of uterine blood flow in third trimester human pregnancy and relation to birthweight - Permission Withheld
David J LOMAS1, Rebecca HAWKES1, Andrew N PRIEST1, Nicholas HILLIARD1, Andrew PATTERSON1, Pat SET1, and Martin J GRAVES1
1Radiology, University of Cambridge & Addenbrooke's Hospital, Cambridge, United Kingdom
Non-invasive measurement of uterine blood flow (UBF) during pregnancy is desirable to assess fetal well-being but difficult using Doppler ultrasound. This work demonstrates an MR method of identifying the uterine arteries in 31 early 3rd trimester normal human pregnancies and quantifying absolute UBF using cine phase contrast. Results are comparable with other methods for quantifying flow and demonstrate a correlation with actual birthweight.  The method has potential for future UBF monitoring during pregnancy.

Three-Dimensional Placental Perfusion Imaging Using Velocity-Selective Arterial Spin Labeling
Zungho Zun1, Ajit Shankaranarayanan2, Nickie Niforatos-Andescavage1, Samantha Bauer1, Diane Lanham1, Dorothy Bulas1, Adre J Du Plessis1, and Catherine Limperopoulos1
1Children’s National Medical Center, Washington, DC, United States, 2GE Healthcare, Menlo Park, CA, United States
Pregnancies complicated by placental insufficiency such as fetal growth restriction and preeclampsia are characterized by reduced placental perfusion. Conventional MR perfusion imaging involves the use of gadolinium-based contrast agents, which are contraindicated in pregnancy. In this study we demonstrate the utility of non-invasive placental perfusion imaging using velocity-selective arterial spin labeling and 3D image acquisition with whole placenta coverage, and present global and regional placental perfusion in high and low-risk pregnancies. Global placental perfusion matched ranges of previously reported values. However, perfusion was heterogeneous and regional placental perfusion measured within the placental lobules reached levels two-fold higher than the global placental perfusion measurement. 

Fetal cardiac MRI and flow measurement using Optimized Doppler Ultrasound Sensor (DUS) gating
Jin Yamamura1, Bjoern Schoennagel1, Manuele Tavares de Sousa2, Christian Ruprecht1, Gerhard Adam1, and Fabian Kording1
1Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany, 2Obstetrics and Reproductive Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
The commonly used method to evaluate the fetal heart is echocardiography (ECG). However, the detection of congenital heart diseases by ECG varies from 45% to 74% and an alternative imaging modality would be desirable. Fetal cardiac MRI has the potential to visualize anatomy and to assess functional parameters of the fetal heart. External fetal cardiac gating using a newly developed Doppler ultrasound sensor (DUS) has been introduced in previous studies. The purpose of this study was to perform fetal cardiac MRI as well as MR flow measurement within great vessels using for external fetal cardiac gating in human fetus and to optimize the device.

Comparative Study of Modelling DW-MRI Data From High-grade Serous Carcinomas and Clear Cell Carcinomas
Feng Wang1, Jianyu Liu1, Yan Zhou1, and Lizhi Xie2
1Radiology Department of Peking University Third Hospital, Beijing, China, People's Republic of, 2GE Healthcare, MR Research China, Beijing, Beijing, China, People's Republic of
The aim of this study was to assess if the histogram analysis of mono-exponential, bi-exponential and stretched exponential models of diffusion-weighted MRI (DW-MRI) parameters can differentiate two common subtypes of ovarian epithelial cancer: high-grade serous carcinomas (HGSCs) and clear cell carcinomas(CCCs). Based on an entire-tumour measurement, the following histogram parameters were derived from ADC, D, D*, F, DDC and α maps, respectively: the mean of the whole tumor, the 10th percentile and the mean of the top 10 percent. We concluded that ADC, D, F, DDC and α have showed good diagnostic performance by analyzing these data.

Diffusion-weighted MR Imaging (DW-MRI) in advanced epithelial ovarian and primary peritoneal cancer: anatomic site-specific changes following neoadjuvant chemotherapy for detecting residual viable tumor
Jennifer C Wakefield1,2, Jessica M Winfield1,2, Gordon Stamp3, Alison MacDonald2, Charlotte Hodgkin4, Ayoma Attygalle2, Desmond Barton2, Robin Crawford4, Susan Freeman4, and Nandita M deSouza1,2
1Division of Radiotherapy and Imaging, Cancer Research UK Cancer Imaging Centre, The Institute of Cancer Research, London, United Kingdom, 2The Royal Marsden Hospital, Sutton, United Kingdom,3Department of Medicine, Centre for Pathology, Imperial College London, London, United Kingdom, 4Departments of Gynaecological Oncology and Radiology, Addenbrooke’s Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom
An understanding of the apparent diffusion coefficient (ADC) changes following neoadjuvant chemotherapy at different metastatic sites in advanced ovarian and primary peritoneal cancer is essential to establish the utility of ADC as a biomarker in site-specific response assessment in this disease. In this study, we found that there was variability in the detection accuracy of DW-MRI between different disease sites and the ADC shows utility as an adjunct to morphological imaging for the detection of viable tumor. Further studies with larger numbers of lesions are needed to interrogate differences between microscopic and non-viable and residual macroscopic tumor fully.

Diagnostic Performance of Endovaginal Zoom EPI Images for Detecting Cervix Cancer after Distortion Correction using Gradient Reversal
Nandita deSouza1, Matthew Orton1, Kate Downey1, Veronica Morgan1, David Collins1, Sharon Giles1, and Geoffrey Payne1
1CRUK/EPSRC Cancer Imaging Centre, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, Sutton, United Kingdom
Diffusion-weighted MRI (DW-MRI) suffers from distortion induced by susceptibility variation and eddy-currents.  To correct this for endovaginal imaging of the uterine cervix, we implemented the forward and reversed gradient technique proposed by Chang and Fitzpatrick in the phase-encode direction and assessed clinical utility of the technique.  This required acquisition of two images of the cervix under the same conditions.  Correction of distortions significantly improved diagnostic performance for an experienced observer when images were viewed with the T2-W images.  Correction allowed definitive diagnosis in a third of cases with tumour volumes of <0.2cm3 classified as equivocal on uncorrected images.

Quantitative DCE-MRI as predictors of immediate ablation efficiency in MR-HIFU treatment of uterine fibroids based on reference region model and entire-tumor histogram analysis
Chenxia Li1,2, Chao Jin1, Ting Liang1,2, Gang Niu1, Yitong Bian1, Keserci Bilgin3, and Jian Yang1,2
1Department of Radiology, The First Affiliated Hospital of Xi’an Jiaotong University, Xi'an, China, People's Republic of, 2Department of Biomedical Engineering, School of Life Science and Technology of Xi’an Jiaotong University, Xi'an, China, People's Republic of, 3Philips Healthcare, Seoul, Korea, Republic of
The aim is to investigate whether quantitative DCE-MRI could be a predictor of immediate ablation efficiency in MR-HIFU of uterine fibroids. 24 eligible female underwent DCE-MRI during screening procedure and immediately after MR-HIFU therapy.They were divided into high non-perfused volume (NPV) ratio (>60%) and low NPV ratio (<60%) group. The reference region model was  used for 3D histogram analysis.All histogram metrics of RR-Ktrans showed  significant difference between two groups. The correlation of RR-Ktrans and NPV ratio was significantly negative (r=-0.6). It indicated that the 3D histogram metrics of  RR-Ktrans might be a sensitive predictor used for patients selection in MR-HIFU.

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