Emer J Hughes¹, Anthony N Price², Laura McCabe¹, Kelly Pegoretti Baruteau¹, Jana Hutter², Olivia Carney¹, Andreia S Gaspar², Joseph V Hajnal², and Mary Rutherford^1
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. 

Jie Luo^1,2, Esra Abaci Turk^1,2, Polina Golland^3,4, Borjan Gagoski¹, Carolina Bibbo⁵, Drucilla J Roberts⁶, Norberto Malpica⁷, Julian N Robinson⁵, Patricia Ellen Grant¹, and Elfar Adalsteinsson^2,3,8
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.

Bailiang Chen^1,2,3, Jie Duan^2,3,4, Jacques Felblinger^1,2,3,5, Olivier Morel^2,3,4, 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.

David J LOMAS¹, Rebecca HAWKES¹, Andrew N PRIEST¹, Nicholas HILLIARD¹, Andrew PATTERSON¹, Pat SET¹, and Martin J GRAVES^1
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.

Zungho Zun¹, Ajit Shankaranarayanan², Nickie Niforatos-Andescavage¹, Samantha Bauer¹, Diane Lanham¹, Dorothy Bulas¹, Adre J Du Plessis¹, and Catherine Limperopoulos^1
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. 

Jin Yamamura¹, Bjoern Schoennagel¹, Manuele Tavares de Sousa², Christian Ruprecht¹, Gerhard Adam¹, and Fabian Kording^1
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.

Feng Wang¹, Jianyu Liu¹, Yan Zhou¹, and Lizhi Xie^2
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.

Jennifer C Wakefield^1,2, Jessica M Winfield^1,2, Gordon Stamp³, Alison MacDonald², Charlotte Hodgkin⁴, Ayoma Attygalle², Desmond Barton², Robin Crawford⁴, Susan Freeman⁴, and Nandita M deSouza^1,2
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.

Nandita deSouza¹, Matthew Orton¹, Kate Downey¹, Veronica Morgan¹, David Collins¹, Sharon Giles¹, and Geoffrey Payne^1
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.

Chenxia Li^1,2, Chao Jin¹, Ting Liang^1,2, Gang Niu¹, Yitong Bian¹, Keserci Bilgin³, and Jian Yang^1,2
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-K^trans showed  significant difference between two groups. The correlation of RR-K^trans and NPV ratio was significantly negative (r=-0.6). It indicated that the 3D histogram metrics of  RR-K^trans might be a sensitive predictor used for patients selection in MR-HIFU.