Janisch H, Leodolter S, Philipp K
Fortschr Med. 1978 Feb 16;96(7):323-6.
Accurate localization of the placenta in the cavity of the uterus is indicated prior to transabdominal amniocentesis and in cases where hemorrhages occur during pregnancy. Several nucleo-medical techniques are available for this purpose. Earlier a so-called placentography was performed, a method later replaced by placental scintigraphy. Today the gamma scintillation camera is ideal for localizing the seat of the placenta. In case of a normally embedded placenta, the profile view makes it possible to determine whether the placenta is attached to the anterior or posterior wall. In case of an anterior wall placenta it is possible with a radioactively labelled marker to draw the outline of the placenta on the abdomen of the patient so that the examiner is certain to puncture in an area that does not contain the placenta. Diagnosis of placenta praevia is assured in all cases by use of the gamma scintillation camera. Short-term introduction of an emitter into the posterior fornix vaginae makes it possible to determine the position of the internal orifice of the cervix uteri. If the caudal part of the placenta extends up to this mark, a placenta praevia is likely and all obstetrical precautions indicated have to be taken.
在进行经腹羊膜穿刺术之前以及怀孕期间发生出血的情况下，需要准确确定胎盘在子宫腔内的位置。为此有几种核医学技术可供使用。早期曾进行过一种所谓的胎盘造影术，该方法后来被胎盘闪烁扫描术所取代。如今，γ闪烁相机是定位胎盘位置的理想设备。对于正常着床的胎盘，侧面观能够确定胎盘是附着在前壁还是后壁。对于前壁胎盘，可以使用放射性标记物在患者腹部勾勒出胎盘的轮廓，以便检查者确定穿刺部位不包含胎盘。使用γ闪烁相机可确保在所有情况下诊断前置胎盘。将放射源短期引入阴道后穹窿能够确定子宫颈内口的位置。如果胎盘的尾部延伸至该标记处，则可能存在前置胎盘，必须采取所有指示的产科预防措施。
