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

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。前言：在美国，大约10%的孕妇会发生先兆子痫，每年至少有20%的产妇死亡和15%的早产是由先兆子痫引起的，在世界范围内，这一数字要高得多。一些证据表明，胎盘植入不良以及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法，我们可以用来研究活体胎盘，而对胎儿的风险最小，而且由于对1.5Tesla的人类胎盘的磁性知之甚少，这项关于产后人类胎盘松弛参数的研究在7个不同的单胎妊娠上进行。胎盘来自：2例健康孕妇，3例轻度PE，2例重度PE。方法和讨论：收集胎盘，固定在装有0.5%氯化钠水的容器中，在出生24小时内用1.5T GE Signa扫描仪在室温下进行MR扫描。记录有关PE严重程度的基本信息。用于发射的单通道体线圈与用于信号接收的8通道磁头线圈配对。所有图像集包括5个穿过胎盘的10 mm(间距5 mm)切片，NEX=1和256×256个数据点。T1图像集由4个TR组成，全部具有最小全TE(14ms)。T2图像集由4个TE组成，TR为2秒。根据方程拟合的最小二乘法计算松弛时间。逐个切片，手工选择不同大小但完全在胎盘内的区域，计算平均松弛时间作为每个区域内逐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S.D.。

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.