1、腹膜转移瘤的腹膜转移瘤的CT诊断诊断及鉴别及鉴别 壁层、脏层腹膜 壁层-贴附于腹壁、横膈脏面和盆壁的内面;脏层-覆盖于内脏表面,成为它们的浆膜层 脏层腹膜将内脏器官悬垂或固定于膈肌、腹后壁或盆腔壁,形成网膜、肠系膜及几个韧带 腹膜腔腹膜腔是壁层腹膜和脏层腹膜之间的潜在间隙,在正常情况下,腹腔内有75100ml黄色澄清液体,起润滑作用。腹膜腔分为大、小腹腔两部分,即腹腔和网膜囊腹膜的解剖结构23 大网膜大网膜是连接胃大弯至横结肠的腹膜,呈围裙状遮被空、回肠 大网膜共四层:包括胃前、后壁的腹膜在胃大弯处愈合,形成大网膜的前两层,向下延伸至脐平面稍下方,然后向后上折返,包被横结肠,形成大网膜的后两层
2、 肠系膜肠系膜包括小肠系膜、横结肠系膜、乙状结肠系膜等4网膜囊(小腹膜腔)网膜囊(小腹膜腔)小网膜和胃后壁及腹后壁的腹膜之间小网膜和胃后壁及腹后壁的腹膜之间的一个扁窄间隙。的一个扁窄间隙。51 1、肠系膜、肠系膜2 2、阑尾系膜、阑尾系膜3 3、横结肠系膜、横结肠系膜4 4、乙状结肠系膜、乙状结肠系膜左肾左肾食管食管左三角韧带左三角韧带 胰胰横结膜横结膜系膜根系膜根 空肠空肠输尿管输尿管乙状结乙状结肠系膜根肠系膜根 直肠直肠膀胱膀胱子宫子宫小肠系膜根小肠系膜根腹主动脉腹主动脉十二指肠降部十二指肠降部肝门静脉肝门静脉右三角韧带右三角韧带冠状韧带冠状韧带肝静脉肝静脉网膜囊上隐窝网膜囊上隐窝6 腹膜
3、转移瘤腹膜转移瘤是腹膜最常见的肿瘤 腹膜转移瘤是腹部恶性肿瘤沿系膜、韧带直接蔓延、腹膜腔种植及淋巴转移、血行转移的结果 原发肿瘤多起源于胃、结肠或卵巢胃、结肠或卵巢,其次为胰腺、胆道或子宫7 血行播散,恶性程度高的原发肿瘤 邻近器官/组织直接蔓延 淋巴道转移:大网膜淋巴系统,右侧膈下淋巴系统(引流至前纵膈淋巴链-右侧淋巴管-锁骨下静脉)当其梗阻出现腹水 腹膜表面播散:重力作用(乙状结肠上部,肠系膜下部,Douglas腔,右侧结肠旁沟);蠕动运动腹膜转移瘤播散途径81、腹水腹水:非特异性,70%,(膈下淋巴道受阻,腹腔液体增多)2、大网膜受累大网膜受累:最先网膜脂肪受累,网膜混浊,有时伴随网膜结
4、节灶,网膜饼(前腹壁后方大网膜扁平如饼状软组织肿块)CT主要表现91011123、肠系膜受累:可表现为小肠位置固定,胃壁增厚,系膜脂肪密度增高,星形系膜肿块,系膜结节(可融合)4、腹膜受累:结节状或弥漫性增厚、可强化,小肠或一段肠管粘附于腹膜壁(间接征象)1314151617181、腹膜假性粘液瘤 肝表面“扇贝样”压迹 腹腔积液形成囊腔 钙化,尤其呈弧形时怀疑 多位于大网膜和横膈膜,较少累及胃肠表面腹膜 阑尾可见液性或软组织团块鉴别诊断1920212、恶性腹膜间皮瘤 石棉暴露相关,4类,恶性,囊性/囊实性,腺瘤样,分化良好的乳头状间皮瘤 胸膜异常表现,钙化斑 无法探及原发肿瘤或继发性肝脏病灶及
5、淋巴结22233、腹膜淋巴瘤 常有淋巴结受累,主动脉前和腹膜后淋巴结肿大,可融合,血管夹心征,软,均质无明显坏死,非梗阻性,相对血供少 脾肿大,不常见 胃肠道侵犯,尤其胃和回肠末端242526274、腹膜结核 出现肠系膜大结节 可见侧腹壁均匀增厚及强化(平滑均匀)脾肿大,脾脏钙化灶 回盲部肠壁受累 后腹膜及胰腺周围的淋巴结肿大,低密度中心及环形强化28Figure 16.Peritoneal tuberculosis in a 45-year old Senegalese male.A and B.Presence of left iliac and splenic hilar lymphad
6、enopathies with necrotic centre(black arrow heads).29C and D.Enhancement and regular thickening of the parietal peritoneum,iliac fossae,and pelvis(white arrow heads)with free ascites(asterisk).30E.Invasion of the greater omentum(black arrow)and lymph nodes of the mesenteric root.315、脾种植 常有外伤脾脏破裂,脾切除
7、史,无临床症状 脾脏碎片种植于腹膜腔,皮下,纵隔、胸膜腔(膈破裂)平扫等密度,增强强化方式同脾脏,无腹水32Figure 17.Incidental sonographic discovery of soft-tissue lesions that are splenosis implants in a 45-year old female with a history of splenectomy following a road accident.A.Note the history of splenectomy(asterisk).Presence of peritoneal tissu
8、e lesions(black arrow heads)in the splenectomy site(C)and in the right peri-renal space(B).33An enhancement study(white arrow heads)found isodensity to the hepatic parenchyma before administration of intravenous contrast material(D),then a non-homogeneous appearance in the arterial phase(E),becoming
9、 homogeneous in the venous phase(F).346、弥漫性腹膜平滑肌瘤病 罕见良性病变,腹膜肌瘤结节(病理似子宫平滑肌瘤)多见于黑人,育龄期妇女,及雌孕激素避孕药摄入有关 主要累及盆腹膜及大网膜,子宫,卵巢,脏层腹膜 延迟强化,无淋巴结肿大及胃壁增厚,无腹水及肝转移灶35Figure 18.A 45-year old female was investigated for a feeling of pressure in the pelvis leading to the incidental discovery of diffuse peritoneal leio
10、myomatosis(DPL)confirmed histologically by diagnostic peritoneoscopy.A and C.Large pelvic soft-tissue mass displacing the adjacent organs,enhancing progressively and non-homogeneously in the venous phase(black arrow heads).36B and D.It becomes homogeneous and enhances more markedly in the delayed phase at 5 min(white arrow heads).37A.壁腹膜呈宽带状、条状、结节状、片絮状或粟粒状强化B.胃周韧带增厚或呈条片状强化C.肠系膜、大网膜呈结节状、饼状、污垢状、囊状影且不均匀强化,或呈条状、粟粒状强化D.肠壁增厚或呈结节状强化,肠腔固定,可见肠道内造影剂充盈跳跃征E.膀胱壁增厚或呈结节状强化;子宫边缘毛糙;双侧附件肿物呈不均匀强化小结3839谢谢观赏!402020/11/5