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这是一个关于胎盘mri检查介绍PPT课件，主要介绍了概述；妊娠滋养细胞疾病；侵袭性葡萄胎和绒毛膜癌；产后妊娠物残留；囊性病变；mri影像，Imaging of the Placenta（二）胎盘影像学表现（二）Sun Mengtian 2012-8-20 Placenta Accreta胎盘植入 During the process of placental development and implantation, a defect in the normal decidua basalis from prior surgery or instrumentation allows abnormal adherence or penetration of the chorionic villi to or into the uterine wall . 由于胎盘植入所造成的手术或仪器使用常常导致基底膜部分缺失，使绒毛膜异常粘着或穿透入子宫壁 The extent of adherence to and invasion of the placental tissue varies: Superficial invasion of the basalis layer is termed placenta accreta (approximately 75% of cases); deeper invasion of the myometrium is termed placenta increta; and even deeper invasion involving the serosa or adjacent pelvic organs is termed placenta percreta. 根据胎盘植入的程度可分为以下几种：表浅的基底膜受侵（约占75%）；子宫肌层受侵；子宫浆膜或子宫周围组织受侵 This abnormal adherence of the placenta to the uterus can result in catastrophic intrapartum hemorrhage at the time of placental delivery, often necessitating emergent hysterectomy . 胎盘植入常可导致分娩时出血 Placenta Accreta胎盘植入 US and Doppler imaging have been shown to be effective imaging strategies for the detection of placenta accreta when applied to a clinically high-risk population, such as those with prior uterine surgery or placenta previa. 超声和多普勒成像已经证实是诊断胎盘植入的有效检查手段，尤其是高危人群如曾有子宫手术史或前置胎盘史的患者，欢迎点击下载胎盘mri检查介绍PPT课件哦。
胎盘mri检查介绍PPT课件是由红软PPT免费下载网推荐的一款疾病PPT类型的PowerPoint.
Imaging of the Placenta（二） 胎盘影像学表现（二） Sun Mengtian 2012-8-20 Placenta Accreta胎盘植入 During the process of placental development and implantation， a defect in the normal decidua basalis from prior surgery or instrumentation allows abnormal adherence or penetration of the chorionic villi to or into the uterine wall . 由于胎盘植入所造成的手术或仪器使用常常导致基底膜部分缺失，使绒毛膜异常粘着或穿透入子宫壁 The extent of adherence to and invasion of the placental tissue varies: Superficial invasion of the basalis layer is termed placenta accreta (approximately 75% of cases); deeper invasion of the myometrium is termed placenta increta; and even deeper invasion involving the serosa or adjacent pelvic organs is termed placenta percreta. 根据胎盘植入的程度可分为以下几种：表浅的基底膜受侵（约占75%）；子宫肌层受侵；子宫浆膜或子宫周围组织受侵 This abnormal adherence of the placenta to the uterus can result in catastrophic intrapartum hemorrhage at the time of placental delivery， often necessitating emergent hysterectomy . 胎盘植入常可导致分娩时出血 Placenta Accreta胎盘植入 US and Doppler imaging have been shown to be effective imaging strategies for the detection of placenta accreta when applied to a clinically high-risk population， such as those with prior uterine surgery or placenta previa. 超声和多普勒成像已经证实是诊断胎盘植入的有效检查手段，尤其是高危人群如曾有子宫手术史或前置胎盘史的患者 MR imaging is most useful in cases where the sonographic findings are equivocal or when the placenta has a posterior location. MRI常应用于超声难以确诊或胎盘后置时 MR imaging features considered diagnostic of placenta accreta include abnormal uterine bulging， heterogeneous placental signal intensity on T2-weighted images， and the presence of dark intraplacental bands related to lacunae on T2-weighted images. MRI诊断胎盘植入的特征主要是胎盘增生，包括子宫异常隆起，T2上盈盘信号不均，以及胎盘边缘黑色的裂隙 (b) MR image shows intermediate-signal-intensity placental tissue (arrowhead) invading the normal dark myometrium (M) in the lower uterine segment. (c) Sagittal MR image shows obliteration of the normal dark myometrium (M) posteriorly， with placental tissue of heterogeneous signal intensity (arrowheads) penetrating the full thickness of the uterine wall. B图：MR显示胎盘组织（箭头所示）在子宫下方侵犯子宫正常肌层（M） C图：MR显示在子宫后份，正常低信号子宫肌层（M）被不均匀高信号（箭头）侵袭 Gestational Trophoblastic Disease 妊娠滋养细胞疾病 Gestational trophoblastic disease encompasses hydatidiform moles， invasive moles， and choriocarcinoma. First-trimester bleeding is one of the most common clinical presentations for this group of disorders. Other clinical signs and symptoms include rapid uterine enlargement， excessive uterine size for gestational age. 妊娠滋养细胞疾病包括完全性葡萄胎、部分性葡萄胎及绒癌 。其最常见的临床症状是怀孕前月阴道出血，其它临床症状包括子宫异常增大超过正常孕周胎盘体积。 The common feature for this group of disorders is the abnormal proliferation of trophoblastic tissue with excessive production of β–human chorionic gonadotropin (β-hCG). 这组疾病的典型特点是滋养层的增生，伴随有人体绒毛膜促性腺激素（ β-hCG）的过度分泌 Hydatidiform Mole葡萄胎 Hydatidiform moles occur in 1 of every 1000– 2000 pregnancies and are classified into two major types—complete and partial—with distinctive histologic and genetic features. 每1000-2000例妊娠就有一次葡萄胎。葡萄胎可分为两种类型：部分性和完全性，区别在于其组织学及遗传基因的区别 The complete hydatidiform mole is the most common form of gestational trophoblastic disease. Complete moles result from fertilization of an empty ovum with subsequent duplication of the paternal chromosomes. 完全性葡萄胎是妊娠滋养细胞疾病中最常见的一种，由一个细胞核基因物质缺失的空卵与一个单倍体精子受精，经自身复制为二倍体 At pathologic analysis， the trophoblastic tissue appears as a complex multicystic mass， classically described as a “cluster of grapes” 病理学分析，其滋养层组织类似一复杂的多囊性肿块，描述为“葡萄串”样 Hydatidiform Mole葡萄胎 At US， complete moles appear as a heterogeneous echogenic endometrial mass with multiple variable-sized small anechoic cysts， giving the appearance of a “snowstorm”. There is no identifiable fetal tissue. 超声显示，完全性葡萄胎表现为不均匀回声的子宫内膜内多个大小不等的无回声囊肿，类似“暴风雪”的外观。没有可识别的胎儿组织 Partial moles appear similar to complete moles but are differentiated by the presence of fetal tissue. Distinction between the two forms can be difficult but is of limited clinical significance， as the management is similar. 部分性葡萄胎超声表现与完全性葡萄胎类似，但区别在于部分性葡萄胎有胎儿组织 Hydatidiform Mole葡萄胎 Invasive Mole and Choriocarcinoma 侵袭性葡萄胎和绒毛膜癌 Invasive moles represent deep growth of the abnormal tissue into and beyond the myometrium， sometimes with penetration into the peritoneum and parametrium. 侵袭性葡萄胎侵袭程度较深，超过子宫肌层，部分侵袭至腹膜及子宫旁组织 Choriocarcinomas are similar to invasive moles but are capable of metastasizing， frequently manifesting with lung and pelvic metastases. Approximately 50% of choriocarcinomas arise after a molar pregnancy， 25% arise after abortion， and 25% arise after a normal pregnancy. 绒毛膜癌与侵袭性葡萄胎类似但有远处转移的特征，多转移至肺及盆腔。大约50%的绒毛膜癌发生于葡萄胎之后，25%发生于流产之后，而25%则发生于正常妊娠后 Invasive moles and choriocarcinomas are largely indistinguishable at imaging. At sonography， both appear as heterogeneous， echogenic， hypervascular masses. Areas of intralesion necrosis and hemorrhage can be seen within choriocarcinoma. 侵袭性葡萄胎和绒毛膜癌的影像学有明显特征性，超声显示，这两种病变均表现为不均匀回声表现的多血管性肿块。绒毛膜癌肿块内常出现坏死和出血。 Choriocarcinoma is one case in which CT is used to evaluate placental disease， as there is no danger of fetal irradiation. However， the appearance of the primary tumor is nonspecific， manifesting as heterogeneous predominantly hypoattenuating intrauterine tissue. CT is particularly useful for staging choriocarcinoma by allowing detection of distant metastases. 由于没有正常胎儿，绒毛膜癌是CT可以用来检查的胎盘病变。原发肿瘤常常表现为不均匀的子宫内低密度，CT常用于判定其分期 Although rarely used， MR imaging can have a role in demonstrating myometrial and parametrial invasion. MR常用来评价子宫肌层和子宫旁的受侵情况 Choriocarcinoma is usually seen as an intrauterine mass with heterogeneous high signal intensity on T2-weighted images and marked enhancement on postcontrast images， findings that reflect the high vascularity of the tumor. Tumor vacularity can also be reflected by focal signal voids on T1- and T2-weighted images. 绒毛膜癌常表现为不均匀的长T2信号，增强后明显强化。由于其富血管性的病理特征，其常常表现为T1、T2上的流空信号。 Myometrial invasion is visible as high-signal-intensity foci within the myometrium， which demonstrate enhancement on postcontrast images. Enhancing parametrial soft tissue is characteristic of local spread. MR imaging can also help detect metastatic disease， particularly within the pelvic organs and lymph nodes. 子宫肌层受侵常表现为正常肌层内的高信号组织，增强后明显强化。而宫旁侵袭则表现为子宫旁的明显强化的软组织团块。MR还可用于评价淋巴结和远处转移 Invasive mole in a patient with an elevated β-hCG level. B = bladder， R = rectum. (a) Axial T2-weighted MR image shows a bright mass in the uterine fundus. The mass disrupts the normal dark myometrial line (M) in the left lateral uterus (arrowheads). (b) Gadolinium-enhanced MR image shows avid enhancement of the mass (arrowheads). 侵袭性葡萄胎患者，伴有人体绒毛膜促性腺激素增多。B为膀胱，R为直肠。图A：T2轴位表现为左侧子宫底部肌层正常连续性中断，可见一团块状不均匀高信号（M）。图B：增强后该肿块呈明显不均匀强化（箭头） Choriocarcinoma. (a) Sagittal T2-weighted MR image shows a mass of heterogeneous signal intensity (white arrowheads) in the uterine fundus; the mass invades into the posterior uterine wall. The internal foci of low signal intensity (black arrowhead) are flow voids， which are suggestive of marked vascularity. (b) Contrast-enhanced T1-weighted MR image shows avid enhancement of the mass (white arrowheads). and the mass has central low signal intensity (black arrowhead)， which represents necrosis. 绒毛膜癌。图A：矢状位T2显示子宫底部一不均匀的高信号肿块侵入子宫肌层后壁（白色箭头），内可见流空信号为血管表现（黑色箭头）B图：增强后肿块呈明显不均匀强化（白色箭头），内可见片状低信号（黑色箭头）为坏死 Retained Products of Conception 产后妊娠物残留 The diagnosis of RPOC is suspected when routine examination of the placenta at delivery reveals an incomplete placenta or when a pregnant patient presents with vaginal bleeding in the first trimester and abnormal material is appreciated within the uterine canal. 产后妊娠物残留多表现为产出胎盘不完整或妊娠早期阴道出血 US is typically the imaging modality employed when RPOC are suspected. Transvaginal imaging is reportedly more sensitive and specific than transabdominal imaging. 超声尤其是经阴道超声比经腹超声对产后妊娠物残留诊断更敏感 At MR imaging， RPOC typically appear as heterogeneous-signal-intensity masses on T1- and T2-weighted images. Variable enhancement is observed on postcontrast images. 产后妊娠物残留多表现为不均匀长T1不均匀长T2信号，增强后呈不均匀强化 T2-weighted (a) and contrast-enhanced spoiled gradient-recalled acquisition in the steady state (b) MR images， obtained in another patient， show a mass in the uterine fundus (arrowheads) that invades the myometrium. The mass has heterogeneous signal intensity on the T2-weighted image and is isointense on the T1-weighted image with uniform enhancement. T2和增强后MRI显示子宫底部（箭头）一肿块，肿块侵入子宫肌层，呈不均匀长T２信号，且增强后呈明显强化 Nontrophoblastic placental tumors are quite rare. Chorioangiomas are the most common， occurring in less than 1% of pregnancies. Placental teratomas are extremely rare and are similar in appearance to chorioangiomas， but are differentiated by the presence of calcifications. 非滋养层胎盘肿瘤比较少见，绒毛膜血管瘤是其中最常见的肿瘤，发生率少于１％妊娠。胎盘畸胎瘤也非常少见，且与绒毛膜血管瘤表现相似，但其特征性表现为钙化 Given that the vast majority of chorioangiomas are incidentally identified， the sonographic characteristics are best described. These lesions appear as well-circumscribed， rounded， hypoechoic or mixed-echogenicity masses protruding from the fetal side of the placenta. 大多数绒毛膜血管瘤表现较典型，超声多表现为边缘光滑、类圆形、低回声肿块，病变多位于胎儿一侧向腔内突出 MR imaging is used only as an adjunct for further evaluation in equivocal cases. Chorioangiomas are isointense on T1-weighted images with increased signal intensity on T2-weighted images. Focal areas of increased signal intensity on T1- and T2-weighted images correspond to intralesion hemorrhage. MR多用于诊断无法确诊的病例，绒毛膜血管瘤多表现为等T1长T2信号，内可伴出血呈短T1短T2信号 Chorioangioma. (a) Power Doppler image shows a heterogeneous mass on the fetal surface of the placenta with internal vascularity and a large feeding vessel (arrow). (b) Gray-scale US image shows the large， well-ircumscribed mass arising from the surface of the placenta (P) immediately adjacent to the insertion of the umbilical cord (C). 绒毛膜血管瘤。A图：多普勒超声显示胎盘内胎儿面不均匀回声肿块，内可见血管回声（箭头）B图:肿块边界清楚，由胎盘的胎儿面长出，与脐带（C）相邻 Metastases转移瘤 Involvement of the placenta by metastatic disease is extremely rare， with fewer than 100 cases reported in the literature， to our knowledge. Placental metastases are believed to arise due to hematologic dissemination of tumor cells， which lodge in the intervillous space of the placenta. 胎盘转移瘤十分罕见，至今文献统计少于100例。胎盘转移多源于血行播散，肿瘤细胞多位于胎盘的绒毛间隙 Melanoma is by far the most common tumor to involve the placenta， followed by leukemia-lymphoma， lung cancer， breast cancer， sarcoma， gynecologic tumors， and gastric tumors. 胎盘转移瘤的最常见原发瘤为黑色素瘤，其次为淋巴瘤、肺癌、乳腺癌、肉瘤、妇科肿瘤以及胃癌 Cystic Lesions囊性病变 The vast majority of hypoechoic foci in the placenta represent intervillous space thrombi or decidual septal cysts. 胎盘的囊性病变多见于绒毛间隙栓子或蜕膜隔囊肿 Intervillous space thrombi form due to focal fetal hemorrhages that rapidly thrombose in the maternal blood pool of the intervillous space. Decidual septal cysts are related to focal degeneration within the maternal decidual septa. 绒毛间隙栓子多由于胎儿出血产生血栓栓塞于绒毛间隙。蜕膜隔囊肿则多由母体蜕膜隔退化形成 Most intervillous space thrombi and decidual septal cysts are visible as hypoechoic foci smaller than 1–2 cm and are of limited clinical significance. 绒毛间隙栓子和蜕膜隔囊肿多表现为低回声，小于1-2CM的囊性病变，大于3CM Cystic Lesions囊性病变 Placental cyst. Doppler US image shows an anechoic spherical structure (arrowhead) on the fetal surface of the placenta. The structure is immediately adjacent to the insertion of the umbilical cord. There is no internal flow， a finding consistent with a placental cyst. 胎盘囊肿。多普勒超声显示无回声肿块（箭头）在胎盘的胎儿侧。病变与脐带相邻，内无血流 Thank You !
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