Zaidi Sadaf F, Moshiri Mariam, Osman Sherif, Robinson Tracy J, Siebert Joseph R, Bhargava Puneet, Katz Douglas S
*Department of Radiology, University of Washington School of Medicine; †Seattle Radiologists; ‡Department of Laboratories, Seattle Children's Hospital, Seattle, WA; and §Department of Radiology, Winthrop-University Hospital, Mineola, NY.
Ultrasound Q. 2016 Mar;32(1):25-42. doi: 10.1097/RUQ.0000000000000157.
The placenta has a fundamental role in fetal health and functions as an important bridge to normal fetal development throughout pregnancy. A complete fetal ultrasound (US) survey should include full assessment of the placenta for any possible abnormalities. Placental diseases range from abnormal morphology, size, location, extent, and degree of placentation, to abruption and the presence of rare placental neoplasms of benign or malignant nature. Some of these conditions are associated with other diseases including aneuploidies, and their discovery should alert the radiologist to perform a very thorough fetal US examination. At times, a fetal karyotype may be needed to provide additional information. Timely detection of placental abnormalities can alert the clinician regarding the need to make important management decisions to reduce fetal and maternal morbidity and mortality. Familiarity with the normal and abnormal imaging appearance of the placenta is therefore necessary for the radiologist. Ultrasound with Doppler is the initial imaging modality of choice for placental assessment. Magnetic resonance imaging serves as a problem-solving examination in instances where the US findings are equivocal or where additional information is needed. Computed tomography has a limited role in the evaluation of placental disease because of its relatively limited tissue characterization and in particular because of the resultant direct radiation exposure of the fetus. However, in specific instances, particularly after trauma, computed tomography can provide invaluable information for patient management.
胎盘在胎儿健康方面起着至关重要的作用,在整个孕期是胎儿正常发育的重要桥梁。完整的胎儿超声(US)检查应包括对胎盘进行全面评估,以发现任何可能的异常情况。胎盘疾病范围广泛,从形态、大小、位置、范围及胎盘植入程度异常,到胎盘早剥以及罕见的良性或恶性胎盘肿瘤。其中一些情况与包括非整倍体在内的其他疾病相关,其发现应提醒放射科医生进行非常全面的胎儿超声检查。有时,可能需要进行胎儿核型分析以提供更多信息。及时发现胎盘异常可提醒临床医生有必要做出重要的管理决策,以降低胎儿和母亲的发病率及死亡率。因此,放射科医生必须熟悉胎盘的正常和异常影像学表现。超声联合多普勒是胎盘评估的首选初始影像学检查方法。当超声检查结果不明确或需要更多信息时,磁共振成像可作为一种解决问题的检查手段。计算机断层扫描在胎盘疾病评估中的作用有限,因为其组织特征相对有限,尤其是会导致胎儿直接受到辐射暴露。然而,在特定情况下,特别是在创伤后,计算机断层扫描可为患者管理提供宝贵信息。