Filiz Yetisir¹, Esra Abaci Turk^1,2, Judy A Estroff^3,4, Carol Barnewolt^3,4, Elfar Adalsteinsson^5,6,7, Patricia Ellen Grant^1,2,3, and Lawrence L Wald^6,8,9
1Fetal-Neonatal Neuroimaging and Developmental Science Center, Boston Children's Hospital, Boston, MA, United States, ²Department of Pediatrics, Boston Children's Hospital, Boston, MA, United States, ³Department of Radiology, Boston Children's Hospital, Boston, MA, United States, ⁴Maternal Fetal Care Center, Boston Children's Hospital, Boston, MA, United States, ⁵Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States, ⁶Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, United States, ⁷Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, United States, ⁸Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, ⁹Department of Radiology, Massachusetts General Hospital, Boston, MA, United States

3T can improve fetal MRI compared to 1.5T, but concerns over increased RF safety risk for the fetus exist due to higher field nonuniformity. Previous studies comparing fetal SAR between two field strengths used either a single pregnant body model or artificial pregnant body models. In this study, we compare SAR and temperature increase in the fetus and mother at 1.5T and 3T using 5 anatomically realistic and diverse pregnant body models. Across these models, we find similar or lower levels of fetal SAR and temperature increase at 3T compared to 1.5T.  

Jeffrey N Stout¹, Esra Abaci Turk¹, Borjan Gagoski¹, Mary Katherine Manhard^2,3, William H Barth, Jr.⁴, Elfar Adalsteinsson^5,6, and P. Ellen Grant^1
1Fetal-Neonatal Neuroimaging Developmental Science Center, Boston Children's Hospital, Boston, MA, United States, ²Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States, ³Department of Radiology, University of Cincinnati College of Medicine, Cincinnati, OH, United States, ⁴Maternal-Fetal Medicine, Massachusetts General Hospital, Boston, MA, United States, ⁵Institute of Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, United States, ⁶Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States

T2* imaging has been the focus of research into the non-invasive MRI assessment of placental function, yet the fundamental physiology that determines placental T2* is under active investigation. We explored the effect of maternal breath holding on placental T2* quantified with multi-echo GRE EPI. We quantified T2* in free-breathing and breath hold periods by identifying voxels that responded to the breath hold stimulus through fitting with a GLM, and found a consistent positive increase in T2* during breath hold. This increase may be evidence that fetal SO2 rises during mild maternal hypercapnia, as has been observed previously in instrumented animals.

George Hutchinson¹, Neele Dellschaft¹, Nia Jones², Lopa Leach³, and Penny Gowland^1
1Sir Peter Mansfield Imaging Centre, The University of Nottingham, Nottingham, United Kingdom, ²Department of Child Health, Obstetrics and Gynaecology, School of Medicine, The University of Nottingham, Nottingham, United Kingdom, ³School of Life Sciences, The University of Nottingham, Nottingham, United Kingdom

Diffusion weighted imaging is commonly used in the placenta to characterise regions of differing structure and flow, including differences between the healthy and compromised placenta. Typically placental diffusion data is described by a combination of exponential decays with increasing diffusion weighting, but we have observed signals that show oscillations in signal or even increasing initial signal and are likely to relate to refocusing caused by coherent flows. By altering our diffusion fitting we can access information about flow patterns and provide more information regarding placental haemodynamics. 

Andrew Melbourne¹, Carla Avena Zampieri¹, Dimitra Flouri¹, Joseph V Hajnal¹, Anna David², Mary A Rutherford¹, Jana Hutter³, and Lisa Story^4
1Centre for Medical Engineering, King's College London, London, United Kingdom, ²University College London, London, United Kingdom, ³King's College London, London, United Kingdom, ⁴Women's Health, King's College London, London, United Kingdom

Preterm premature rupture of membranes (PPROM) complicates up to 40% of deliveries less than 37 completed weeks gestation. Absence of clinical symptoms means that fetal infection can be missed and later complications are significantly higher. There is thus a real need for non-invasive antenatal assessment of the early signs of placental inflammation. This study combines an efficient multimodal Diffusion-Relaxation acquisition with dedicated analysis to study the placental phenotype associated with PPROM. Initial results indicate  that multi-modal MRI measurement of placental function is linked to eventual gestational age at delivery.

Daphna Link¹, Netanell Avisdris^1,2, Xingfeng Shao³, Liat Ben Sira^4,5, Liran Hiersch⁶, Ilan Gull⁷, Danny J.J. Wang⁸, and Dafna Ben Bashat^1,4
1Sagol Brain Institute, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel, ²School of Computer Science and Engineering, The Hebrew University of Jerusalem, Jerusalem, Israel, ³Laboratory of FMRI Technology (LOFT), USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States, ⁴Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel, ⁵Division of Pediatric Radiology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel, ⁶Division of Obstetrics and Gynecology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel, ⁷Ultrasound Unit, Lis Maternity Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel, ⁸3Laboratory of FMRI Technology (LOFT), USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States

Adequate placental structure and function are crucial for fetal and maternal health. Here we assessed late-gestation placental perfusion (N=50, GA=31-38 weeks) using pseudocontinuous arterial-spin-labeling and radiomics feature-extraction, and their association with umbilical-cord insertion-site and the risk of fetal-growth-restriction (FGR).   Increased blood-flow and arterial-transit-time were detected in our normal cases compared to earlier gestation as reported previously. Perfusion features differences were detected in placentas with marginal compared to central cord-insertion, indicating higher intensity heterogeneity. No differences were found between normal and FGR placentas.  This study provides normal late-gestation placental perfusion values based on a large cohort, and implies on structural-functional associations.

Lindsay E. Morris¹, Lanette J. Friesen-Waldner¹, Trevor P. Wade¹, Lauren M. Smith², Mary-Ellen ET. Empey¹, Timothy RH. Regnault^3,4,5, and Charles A. McKenzie^1,5
1Medical Biophysics, Western University, London, ON, Canada, ²Radiation Oncology, University of California Los Angeles Health, Los Angeles, CA, United States, ³Physiology and Pharmacology, Western University, London, ON, Canada, ⁴Obstetrics and Gynaecology, Western University, London, ON, Canada, ⁵Division of Maternal, Fetal and Newborn Health, Children's Health Research Institute, London, ON, Canada

Effects of a life-long maternal Western Diet (WD: high fat and high sugar diet) on placental metabolism in 33- and 60-day gestation guinea pigs were investigated. Pregnant WD or control diet (CD) fed sows underwent T1-weighted and ¹³C hyperpolarized metabolic MRI at 3T. Metabolite mean signal intensities were measured in the placental volumes as a function of time and area under the curve (AUC) ratios were calculated for pyruvate and its metabolites: lactate, bicarbonate & alanine. The AUC ratios for lactate and bicarbonate were significantly higher in WD than CD groups, suggesting placental metabolic dysfunction.

Ruiming Chen¹, Ante Zhu², Kevin M. Johnson^1,3, Ian M. Bird⁴, Kathleen M. Antony⁴, J. Igor Iruretagoyena⁴, Scott B. Reeder^1,3,4,5,6, Diego Hernando^1,3,7,8, Dinesh M. Shah⁴, and Oliver Wieben^1,3
1Medical Physics, University of Wisconsin - Madison, Madison, WI, United States, ²GE Global Research, Niskayuna, NY, United States, ³Radiology, University of Wisconsin - Madison, Madison, WI, United States, ⁴Obstetrics & Gynecology, University of Wisconsin - Madison, Madison, WI, United States, ⁵Medicine, University of Wisconsin - Madison, Madison, WI, United States, ⁶Emergency Medicine, University of Wisconsin - Madison, Madison, WI, United States, ⁷Biomedical Engineering, University of Wisconsin - Madison, Madison, WI, United States, ⁸Electrical and Computer Engineering, University of Wisconsin - Madison, Madison, WI, United States

Fetal growth restriction (FGR) is associated with placental hypoxia, which can be identified by measuring placental T2* value in-vivo. In this pilot study, we acquired T2* maps in 2 subjects in late pregnancy diagnosed with FGR. Mean and histogram of T2* and R2* values in the placenta were analyzed for two timepoints after administration of ferumoxytol reflecting T2* maps dominated by the presence of the iron nanoparticles and a baseline. We observed lower baseline T2* values than previously reported in healthy controls at similar gestation as well as lower baseline T2* values as reported in FGR patients earlier in gestation.

Janina Schellenberg¹, Rosalind Aughwane², Dimitra Flouri¹, Nada Mufti², Katarzyna Maksym², Anna L. David², and Andrew Melbourne^1
1Kings College London, London, United Kingdom, ²University College London, London, United Kingdom

Babies with fetal growth restriction fail to grow properly in the womb and become hypoxic. They must be delivered prematurely to prevent stillbirth. DECIDE model fitting can determine properties which give information about the placental function and fetal blood saturation. This can be used to identify fetal growth restriction and manage the pregnancy effectively.

The aim is to compare DECIDE model fitting results for different mask segmentations. The placenta is segmented into lobules and used as a mask itself. Statistically significant differences of the fetal and placental properties between appropriately developing and growth-restricted pregnancies are determined.

Mbaimou Auxence Ngremmadji¹, Robin Draveny¹, Audrey Krisch², Khalid Ambarki³, Dominik NICKEL⁴, Charline Bertholdt^1,5, Olivier Morel^1,5, Marine Beaumont^1,2, and Bailiang Chen^1,2
1IADI, Inserm U1254, Université de Lorraine, Nancy, France, ²CIC-IT 1433, Inserm, CHRU Nancy, Nancy, France, ³Siemens Healthineers, Nancy, France, ⁴MR Applications Predevelopment, Siemens Healthcare GmbH, Erlangen, Germany, ⁵Women's Division, Nancy Regional and University Hospital Center (CHRU), Université de Lorraine, Nancy, France, Nancy, France

Placenta adhesion abnormality (PAA) is the consequence of an excessive invasion of the placenta within the myometrium. Due to its severe maternal pregnancy outcomes, screening of subjects with suspicions of PAA are very important. The utilisation of intra voxel incoherent motion (IVIM) technique may help to improve the diagnosis. But its stability and robustness need to be improved and analysed.  Here we aim to evaluate the impact and address the importance of motion correction technique to assess PAA disorders in-vivo  using IVIM method in order to establish a robust and stable pipeline for PAA patient screening.

Simran Sethi¹, Lanette J. Friesen-Waldner¹, Trevor P. Wade^1,2, Ousseynou Sarr³, Brian Sutherland³, Timothy R.H. Regnault^3,4,5, and Charles A. McKenzie^1,2,5
1Medical Biophysics, Western University, London, ON, Canada, ²Robarts Research Institute, Western University, London, ON, Canada, ³Physiology and Pharmacology, Western University, London, ON, Canada, ⁴Obstetrics and Gynaecology, Western University, London, ON, Canada, ⁵Maternal, Fetal & Newborn Health, Children's Health Research Institute, Lawson Research Institution, London, ON, Canada

Myelin water fraction (MWF), a validated marker for myelin lipid, can be used to assess fetal myelination in vivo. Thus, this study aims to demonstrate the feasibility of quantifying fetal MWF. 11 pregnant guinea pigs with 38 fetuses were imaged in a 3T MRI. mcDESPOT was used to quantify MWF in the corpus callosum (CC) of the maternal brain and the CC and fornix (FOR) of the fetal brain. MWF maps were successfully generated in all fetal brains, confirming its feasibility. Maternal MWF results and comparison of fetal CC and FOR MWF results are consistent with published results. 

Lisan M. Morsinkhof¹, Anique T.M. Grob², Lianne Straetemans¹, and Frank F.J. Simonis^1
1Magnetic Detection & Imaging, University of Twente, Enschede, Netherlands, ²Multi-Modality Medical Imaging, University of Twente, Enschede, Netherlands

Pessary treatment for pelvic organ prolapse (POP) has a success rate of only 63% and its working mechanism remains unclear. This study applies upright MRI to gain insight into pessary. Patients were scanned in supine and upright position. The pessary was located under the inferior pubic bone in 7 out of 9 patients in upright position, opposed to 1 out of 9 in supine position. This indicates that the pubic bone does not (solely) contribute to the supporting mechanism. The use of upright MRI contributes to knowledge about the working mechanism of the pessary.  

Anugayathri Jawahar¹, Perla Subbaiah ², and Vipul R Sheth^3
1Radiology, Loyola University Medical Center, Maywood, IL, United States, ²Biostatistics, Oakland University, Rochester, MI, United States, ³Radiology Body MRI, Stanford University Medical Center, Palo Alto, CA, United States

Pelvic floor dysfunction is a common problem affecting women over 50 years of life causing significant morbidity. Traditionally, H-line and M-line measurements have been used to assess pelvic organ prolapse. However, puborectalis muscle which plays a crucial role in pelvic floor intactness can be measured to reflect the weakening of the pelvic floor. We evaluated and found puborecatalis measurement can be used as a supplement to H-line and M-line measurements in assessing pelvic organ prolapse.