腹膜后脂肪性病变.ppt

腹膜后含脂肪病变的影像特点和鉴别诊断,杨云飞,The complex anatomy of the retroperitoneum is reected in the spectrum of neoplastic and nonneoplastic conditions that can occur in the retroperitoneum and appear as soft-tissue masses.The presence of fat within a retroperitoneal lesion is helpful in refning the differential diagnosis腹膜后的复杂解剖结构反映在可以发生在腹膜后的表现为软组织肿块肿瘤性和非肿瘤性疾病中腹膜后病变内脂肪的存在有助于鉴别诊断,福建省立医院影像科,Fat is easily recognized because of its characteristic imaging appearance It typically is hyperechoic at ultrasonography and demonstrates low attenuation at computed tomography(-10 to-100 HU)脂肪因为其特有的影像特点很容易被识别 它通常在超声检查呈高回声，并在CT检查中表现为低密度（-10至-100HU）,福建省立医院影像科,Magnetic resonance imaging is a more ideal imaging modality because it has better soft-tissue image contrast and higher sensitivity for depicting(a)microscopic fat by using chemical shift imaging and(b)macroscopic fat by using fatsuppression techniques.磁共振成像是一种更理想的成像方式，因为它具有更好的软组织图像对比度和更高的灵敏度，用于描绘（a）通过使用化学位移成像显示肉眼不可见的脂肪和（b）通过使用脂肪抑制技术显示肉眼可见的脂肪,福建省立医院影像科,Multiple imaging signs help to determine the organ of origin,including the“beak sign,”the“embedded organ sign,”the“phantom(invisible)organ sign,”and the“prominent feeding artery sign.”Adrenal adenoma is the most common adrenal mass that contains microscopic fat,while myelolipoma is the most common adrenal mass that contains macroscopic fat.多个成像标志有助于确定起源器官，包括“鸟嘴征”，“器官包埋征”，“隐形器官征”和“明显供血动脉征”。肾上腺腺瘤是最常见的包含细微脂肪的肾上腺肿块，而髓质脂肪瘤是包含较大脂肪的最常见的肾上腺肿块,福建省立医院影像科,福建省立医院影像科,鸟嘴征阳性。（a）肿块与肾脏连接处呈锐角，（箭头）。（b）横断面增强CT显示了一个左肾单纯囊肿（黑色箭头）有明显的鸟嘴征（白色箭头），这意味着囊肿起源于肾。,福建省立医院影像科,反鸟嘴征（a）绘图显示肿块与肾脏交界面呈圆角（箭头）。（b）横断位T2脂肪抑制图像显示在肾周间隙内临近肾包膜的囊性结构（箭头）。囊性结构和肾脏之间的钝圆形交界面表明它不是起源于肾脏。,福建省立医院影像科,器官反包埋征。（a）图显示肿瘤压迫空腔器官，呈新月形。（b）横断位T1增强抑脂像显示原发性腹膜后副神经节瘤（白色箭头）压迫下腔静脉（箭头），使它呈月牙形。肿块和下腔静脉的界面光滑而规则（黑色箭头）。,福建省立医院影像科,器官包埋征阳性（a）示似乎嵌入一个空腔器官壁的肿瘤，来源于空腔器官。（b）冠状位CT增强图像显示从回肠末端肠壁产生肿块。回肠腔被保留，回肠壁包埋于肿块内（箭头）。这些发现代表一个器官包 埋征阳性的回肠间质瘤。,Chemical shift imaging(with in-phase and out-of-phase sequences)is the most reliable MR imaging technique for diagnosing adrenal adenomas.Most of these lesions demonstratea decrease in signal intensity on out-of-phase images when compared with in-phase images.A decrease in signal intensity of more than 16.5%is considered diagnostic of an adenoma.化学位移成像（在同相位和反相位的序列）是用于诊断肾上腺腺瘤最可靠的MR成像技术。与同相位图像相比，这些病变通常表现出反相位图像信号强度的下降。信号强度降低超过16.5被认为是腺瘤的诊断,福建省立医院影像科,TEACHING POINTS,AMLs with minimal fat are usually hyperattenuating relative to the renal parenchyma on nonenhanced CT images and hypointense on T2-weighted MR images,inherent features that reect the predominant smooth-muscle component and classically overlap with features of papillary RCC.乏脂肪的AML通常在CT平扫相对于肾实质呈高密度，在T2加权MR图像上低信号，平滑肌成分的特征与典型乳头状RCC特征重叠,福建省立医院影像科,Differentiating renal lipoma or well-differentiated liposarcoma from AML may be diffcult:AMLs may contain large aneurysmal vessels,while lipomas and liposarcomas are relatively avascular and rarely occur with multiple lesions,as may be seen with AMLs.鉴别肾脂肪瘤或高分化脂肪肉瘤与AML可能存在困难：AMLs可能含有大的动脉瘤血管，而脂肪瘤和脂肪肉瘤相对无血管，很少发生多发性病变，正如AMLs所见,福建省立医院影像科,Retroperitoneal fat necrosis is usually caused by the lipolytic effect of pancreatic enzymes released during acute pancreatitis.It usually is accompanied by pancreatic parenchymal necrosis but can occur without visible pancreatic involvement.Splenectomy may have a role in accelerating development of extramedullary hematopoiesis in uncommon sites.腹膜后脂肪坏死通常由急性胰腺炎期间释放的胰酶的脂解作用引起。它通常伴有胰腺实质坏死，但可以在没有可见的胰腺受累的情况下发生。脾切除可能会加速非常见部位的髓外造血,福建省立医院影像科,女，43岁，肾上腺腺瘤患者。同相位（a）和反相位（b）T1加权MR图像显示左肾上腺肿瘤（箭头）。反相位图像信号减低。,福建省立医院影像科,福建省立医院影像科,女，45岁，肾上腺髓脂瘤患者横断位增强CT图像显示右侧肾上腺肿块含有脂肪（箭头）。由于髓质成分，肿块比腹膜后脂肪密度高。,福建省立医院影像科,女，49岁 肾上腺 AML 患者 横断位平扫 T1呈高信号（a）和（b）T1抑脂信号减低，边缘呈薄壁强化。,福建省立医院影像科,女48岁，有结节性硬化病史。AML 横断位（a）冠状（b）增强CT图像显示左肾含脂肿块（白色箭头），右肾也见到含脂病变（a中的箭头）注意 左肾静脉中的脂肪瘤血栓（黑色箭头）。,福建省立医院影像科,男，56岁RCC患者冠状增强CT图像显示强化的右肾肿块（黑色直箭头）。肿块有软组织密度，小的钙化灶（白箭头）和脂肪密度（弯曲的黑色箭头）。也可见左髂骨转移性溶骨性病变（白色箭头）。,福建省立医院影像科,Renal liposarcoma in a 65-year-old man.Axial contrast-enhanced CT image shows a fat-attenuating lesion in the left kidney(arrows).The lesion extends from the renal sinus to the perinephric fat and iscentered on the renal capsule.Pathologic examinationdemonstrated a well-differentiated liposarcoma arisingfrom the renal capsule.男，65岁。肾脂肪肉瘤横断位增强CT示左肾脂肪密度病变（箭头）。病变从肾窦以肾包膜为中心延伸至肾周脂肪。病理检查显示高分化脂肪肉瘤。,福建省立医院影像科,Pancreatic lipoma in a 62-year-old woman.Axial contrast-enhanced CT image shows a well-circumscribed homogeneous fat-attenuating mass(arrows)in the pancreatic body.女，62岁，胰腺脂肪瘤 横断位增强CT示胰腺内边界清楚的均匀脂肪密度肿块（箭头）。,福建省立医院影像科,Pancreatic mature cystic teratoma in a 33-year-old woman.Axial contrast-enhanced CT image shows a well-circumscribed homogeneous fat-attenuating mass(arrows)in the pancreatic head.Nodular calcifcation(arrowhead)is seen at the periphery of the fatty mass.33岁女性 胰腺成熟囊性畸胎瘤。轴位对比增强CT图像显示在胰头中具有边界清晰的低密度均匀脂肪（箭头），脂肪团周围 结节性 钙化（箭头）。,福建省立医院影像科,Pancreatic lipomatosis in a 23-year-old man with cystic fbrosis.Axial contrast-enhanced CT image shows expansion and complete replacement of the pancreas with lipomatous tissue(arrows).男，23岁，囊性纤维化患者，胰腺脂肪变性横断位增强CT图像显示腺体扩张并被脂肪组织完全替代（箭头）。,福建省立医院影像科,Mesenteric and retroperitoneal panniculitis in a 44-year-old man.Axial nonenhanced CT image shows typical subtle increased attenuation in the mesentery and retroperitoneal fat of the left renal sinus and around the aorta.There is preservation of fat surrounding the mesenteric vessels(arrowheads).A thin band of soft-tissue attenuation(arrows)separates the abnormal mesentery from the surrounding normal fat.男，44岁肠系膜和腹膜后脂膜炎。轴位平扫CT显示左肾和主动脉周围的肠系膜和腹膜后脂肪密度稍增高。肠系膜血管被脂肪包绕（箭头）。软组织密度的薄带影（箭头）将异 常肠系膜与周围正常 脂肪分开,福建省立医院影像科,女，75岁，囊性脂肪坏死，做过RCC的根治性肾切除术。（a）术后5个月的增强CT图像在肾切除术床上显示良好的边界清楚的囊性病变（白色箭头）。具有囊壁、脂液平 面（箭头）和软组织成分（黑色箭头）。（b）7个月后增强CT图像显示了脂肪肿块和 液体及软组织成分的间隔减小。,福建省立医院影像科,Retroperitoneal well-differentiated liposarcoma in a 54-year-old woman.Axial contrast-enhanced CT image shows a retroperitoneal mass(arrows)with fat attenuation and areas of soft-tissue attenuation(arrowheads).Pathologic analysis demonstrated well-differentiated sclerosing liposarcoma.女，54岁，腹膜后高分化脂肪肉瘤。增强的CT图像显示有脂肪和软组织密度（箭头）。病理分析表明高分化硬化性 脂肪肉瘤。,福建省立医院影像科,Lipoblastoma in a 3-year-old boy.Axial contrast-enhanced CT image shows a retroperitoneal mass(arrows)in the right abdomen.The mass has fat attenuation,fne soft-tissue septa,and an area of uid attenuation(arrowhead)due to myxoid material.男，3岁，脂肪母细胞瘤患者 增强CT图像显示右腹部腹膜后肿块（箭头）。有脂肪密度、软组织间隔和由于粘液样物质引起的液体密度（箭头）区域。,Differential Diagnosis of Fat-containing Retroperitoneal Masses,福建省立医院影像科,福建省立医院影像科,Adrenal-肾上腺,extramedullary hematopoiesis-髓外造血Renal-肾脏 beak sign-鸟嘴征Adenoma-腺瘤 embedded organ sign-器官包埋征Pheochromocytoma-嗜铬细胞瘤neurogenic tumors-神经源性肿瘤 Lipoma-脂肪瘤Lipomatosis-脂肪瘤病fat necrosis-脂肪坏死Myelolipoma-髓样脂肪瘤 liposarcoma-脂肪肉瘤primary and secondary GCTs-原发性和继发性生殖细胞瘤neurogenic tumors-神经源性肿瘤,