腹膜转移瘤的CT诊断及鉴别-2课件

1、腹膜转移瘤的CT诊断及鉴别壁层、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肠系膜包括小肠系膜、横结肠系膜、乙状结肠系膜等网膜

2、囊（小腹膜腔） 小网膜和胃后壁与腹后壁的腹膜之间的一个扁窄间隙。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，其次为胰腺、胆道或子宫血行播散，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1、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

3、累及胃肠表面腹膜阑尾可见液性或软组织团块鉴别诊断2、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淋巴结3、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4、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Figure 16. Peritoneal tuberculosis in a 45-year o

4、ld Senegalese male. A and B. Presence of left iliac and splenic hilar lymphadenopathies with necrotic centre (black arrow heads). C and D. Enhancement and regular thickening of the parietal peritoneum, iliac fossae, and pelvis (white arrow heads) with free ascites (asterisk).E. Invasion of the great

5、er omentum (black arrow) and lymph nodes of the mesenteric root.5、脾种植常有外伤脾脏破裂，脾切除史，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Figure 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 ac

6、cident. A. Note the history of splenectomy (asterisk). Presence of peritoneal tissue lesions (black arrow heads) in the splenectomy site (C) and in the right peri-renal space (B). An enhancement study (white arrow heads) found isodensity to the hepatic parenchyma before administration of intravenous

7、 contrast material(D), then a non-homogeneous appearance in the arterial phase(E), becoming homogeneous in the venous phase(F).6、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，与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Figure 18. A 45-year old female was investigated for a feeling of

8、pressure in the pelvis leading to the incidental discovery of diffuse peritoneal leiomyomatosis(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).B and D. It becomes homogeneous and enhances more markedly in the delayed phase at 5 min(white arrow heads).壁腹膜呈宽带状