NMR IMAGING AND RELAXATION PARAMETER MAPPING OF THE HUMAN PLACENTA POST PARTUM

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。导读：在美国，先兆子痫（PE）发生在大约10%的怀孕中，每年在美国至少20%的孕产妇死亡和15%的早产是由它造成的，在世界范围内这些数字要高得多。一些证据表明胎盘植入不良和随后的畸形和功能障碍是这种疾病的根本原因。由于磁共振成像是一种敏感的方式，我们可以在对胎儿风险最小的情况下研究体内胎盘，并且由于对1.5特斯拉时人类胎盘的磁性特性知之甚少，因此本研究对7个不同的单胎妊娠进行了产后人类胎盘松弛参数的研究。收集的胎盘来自：2例健康妊娠，3例轻度PE， 2例重度PE。方法和讨论：收集胎盘，将其固定在0.5% NaCl水的容器中，并在出生24小时内在1.5T GE Signa扫描仪中在室温下进行MR扫描。记录PE严重程度的基本信息。用于发送的单通道体线圈与用于信号接收的8通道头线圈配对。所有图像集由5个10mm的胎盘切片（5mm间距）组成，NEX=1，数据点为256x256。T1图像集由4个tr组成，所有tr都具有最小的完整TE （14 ms）。T2图像集由4个te组成，TR为2秒。根据方程的最小二乘拟合计算松弛时间。逐层手工选择大小不一但完全在胎盘内的区域，并计算平均松弛时间为每个区域内每个像素的松弛时间的平均值，以及每个区域内这些时间的平均sd。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Introduction: In the United States, Pre-Eclampsia (PE) occurs in roughly 10% of pregnancies, and is responsible for at least 20% of maternal deaths and 15% of premature births in the U.S. every year, worldwide these numbers are much higher. Several lines of evidence point towards poor placental implantation and subsequent malformation and dysfunction as a root cause of this disease. Since MR imaging is a sensitive modality with which we can study the in vivo placenta with minimal risk to the fetus, and since very little is known about the magnetic properties of the human placenta at 1.5 Tesla, this study of the relaxation parameters of the post partum human placenta was undertaken on 7 different singleton pregnancies. Placentas were collected from: 2 healthy pregnancies, 3 w/ mild PE, and 2 exhibiting severe PE. Methods and Discussion: Placentas were collected, secured in a container of 0.5% NaCl water, and MR scans performed at room temperature in a 1.5T GE Signa scanner within 24 hours of birth. Basic information about the severity of PE was recorded. A single channel body coil used for transmit was paired with an 8 channel head coil for signal reception. All image sets consisted of five 10mm slices ( 5mm spacing) through the placenta, NEX=1 and 256x256 data points. The T1 image sets consisted of 4 TRs all with a minimum full TE (14 ms). The T2 image sets consisted of 4 TEs with a TR of 2 sec. Relaxation times were calculated from the least squares fit to the equations. Slice by slice, regions of varying sizes but completely within the placenta were chosen by hand, and average relaxation times were computed as the mean of relaxation times pixel by pixel within each region, along with the average S.D. of these times within each region.