粘连性腹内疝及其合并肠缺血坏死的MSCT诊断

目的 探讨粘连性腹内疝及合并绞窄性肠坏死的MSCT特征.方法 回顾性分析21例经手术证实的粘连性腹内疝的CT资料,CT原始数据经多平面重建(MPR)及CT血管造影(CTA),以显示疝环、疝入肠系膜、疝内肠管的特征.结果 19例粘连性腹内疝均显示疝环,小肠扩张积液、聚集并移位,其中17例显示疝环处肠管狭窄与扩张肠管移行;17例显示疝入肠系膜水肿、增厚,肠系膜血管纠集、充血,其中11例显示疝环处肠管及其系膜扭转;15例显示腹水.根据疝入肠管影像表现将粘连性腹内疝分型:Ⅰ型为肠管扩张伴肠壁增厚(7例);Ⅱ型为肠管扩张不伴肠壁增厚(9例);Ⅲ型为肠管不扩张但肠壁增厚(5例).3型腹内疝肠管壁平扫CT值、动脉及门脉期肠壁强化值差异有统计学意义(P<0.05),Ⅰ和Ⅲ型小于Ⅱ型,Ⅰ、Ⅲ型之间的差异无统计学意义(P>0.05).8例粘连性腹内疝合并绞窄性肠坏死(5例为Ⅰ型,3例为Ⅲ型),CT显示肠扭转伴疝入小肠壁显著水肿增厚,肠壁模糊呈持续性低强化,其中4例显示肠系膜上静脉血栓栓塞,3例显示肠系膜上动脉主干或分支闭塞,8例均显示大量腹水.结论 粘连带形成的疝环,狭窄与扩张肠管移行以及小肠扩张、聚集并移位提示粘连性腹内疝的存在;疝入肠系膜水肿,血管纠集,充血,肠系膜血管闭塞,肠管壁显著水肿增厚并持续低强化,则是绞窄性肠坏死的影像特征.

MSCT diagnosis of adhesive abdominal internal hernias and its complication of strangulated intestinal necrosis

Objective To explore the MSCT characteristics of adhesive abdominal internal hernias and its complication of strangulated intestinal necrosis.Methods The CT data of 21 cases with adhesive abdominal internal hernias proved by operation were analyzed retrospectively.Raw data of CT images were reconstructed with MPR and/or CTA procedure for visualizing the hernia ring, intestinal mesentery and ansa interstinalis.Results Adhesive bands (hernia ring), crowding of distended and fluid-filled bowel loops with an abnormal location was visualized in 19 cases, among which the transitional segment from stenosis to dilation of the intestine was visualized in 17 cases.The crowded and engorged mesenteric vessels, edematous mesentery were visualized in 17 cases,among which mesenteric torsion was visualized in 11 cases.Varying amounts of ascites was visualized in 15 cases.All adhesive abdominal internal hernias in our study were classified according to their image manifestation.Dilated intestinal loop with thickened bowel wall was classified to type Ⅰ (7 cases).Dilated intestinal loop with normal bowel wall was classified to type Ⅱ (9 cases).Normal size of the intestinal loop with thickened bowel wall was classified to type Ⅲ (5 cases).The difference of CT values of the intestinal wall on non-contrast CT,enhancement CT values in arterial and portal phase of contrast-enhanced CT among three types of adhesive abdominal internal hernias showed statistical significance (P<0.05).The CT values and CT enhancement for type Ⅰ and Ⅲ were lower compared to type Ⅱ, while the difference of CT values between type Ⅰ and Ⅲ showed no statistical significance (P>0.05).8 cases of adhesive abdominal internal hernias were accompanied by intestinal necrosis (5 cases for type Ⅰ,3 cases for type Ⅲ).The necrotic intestine loop manifested as markedly thickened and blurred bowel wall with reduced enhancement, while thrombosis embolism of SMV was visualized in 4 cases and thrombosis embolism of SMA in 3 cases,respectively.Massive ascites was visualized in 8 cases.Conclusion The adhesion bands,transitional segment of small intestine,gathered and translocated intestinal loops are the clue to the diagnosis of adhesive abdominal internal hernias.Edema of mesentery, gathered and engorged mesenteric vessels, occlusion of SMV or SMA and the conspicuously thickened bowel wall with reduced enhancement are the image characteristics of intestinal necrosis.