20211008湘雅二医院课件荟萃【1823】
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● Clinical Presentation
● 临床表现
● A 42-year-old woman presents with abdominal pain after proctocolectomy for ulcerative colitis. Rule out hematoma.
● 女，42岁，因治疗溃疡性直肠炎行直肠结肠切除术后，腹痛。排除血肿。
● 1A - Annotated Caption
● (A) Contrast-enhanced computed tomography (CT) shows a large, ovoid, heterogeneous mass (arrow) of predominantly fat density in the region of the greater omentum. The mass has a thin, hyperdense rim.
● 1A-注释说明
● (A)对比增强的计算机断层扫描(CT)显示大网膜区域的一个大的卵圆形、不均匀的以脂肪密度为主的肿块(箭头)。肿块有一个薄的高密度的边缘。
● 2B - Annotated Caption
● (B) Coronal reformatting shows the mass displacing colon (arrow).
● 2B-注释说明
● ● (B)冠状位显示的是肿块占位结肠(箭头)。
● Further Work-up
● 进一步检查
● No Further Work-up
● 无进一步检查
● Imaging Findings
● 影像学表现
● Click on Annotated Thumbnail to reveal caption
● Differential Diagnosis
● Omental infarction: This is the overwhelmingly likely diagnosis in this case, and the other items are included primarily for discussion and dismissal.
● Diverticulitis: This is often the principal differential possibility as it too is associated with heterogeneous pericolonic fat. The large, ovoid, heterogeneous mass in this case is not characteristic of diverticulitis.
● Acute epiploic appendagitis: This is extremely unlikely in this case, given the large size of the mass, which is more typical of omental infarction. Acute epiploic appendagitis is more typically associated with a hyperdense rim. The rim seen in this case results from healing omental infarction and was not present it the acute stage of the case.
● 鉴别诊断
● 大网膜的梗死:在这种情况下，极有可能为此诊断，其他表现主要被包括在内，进行讨论和排除。
● 憩室炎:这主要的差异可能也与不均质结肠周围脂肪相关。异构肿块大,卵圆形,在这种情况下不是憩室炎的特征。
● 急性网膜附件炎:在这种情况下是不可能的,考虑到大尺寸的肿块,更像是典型的网膜的梗塞。急性网膜附件炎通常与一个高密度的边缘。这种情况下在急性期是不能看到由于网膜梗塞恢复的边缘。
● Essential Facts
● Omental infarction is fat necrosis of the omentum and may be primary or secondary.
● The primary type may result from torsion or vascular obstruction related to a congenital anomaly. This type usually occurs in children and young adults.
● The secondary type may result from torsion caused by an abdominal mass. Other causes may or may not involve torsion and include obesity, abdominal surgery, trauma, and occlusion of the superior mesenteric artery. This type usually occurs in adults.
● Clinical presentation includes abdominal pain, usually localized to the right lower quadrant, and occasional fever, nausea, vomiting, and diarrhea.
CT typically shows an ovoid, heterogeneous mass containing fat and soft-tissue density, usually between the anterior abdominal wall and the transverse or ascending colon. Omental infarction is usually > 5 cm.
● Spiraling mesenteric vessels may be visible in cases caused by torsion (“whirl” sign, like that seen in volvulus cases).
● 要点
● 网膜梗死的大网膜的脂肪坏死，可能是主要的或次要的。
● 主要类型可能是由于先天性异常引起的扭转或血管阻塞。这种类型通常发生在儿童和年轻人身上。
● 第二型可能是由腹部肿块引起的扭转引起的。其他原因可能或不包括扭转，包括肥胖、腹部手术、创伤和肠系膜上动脉闭塞。这种类型通常发生在成人身上。
● 临床表现包括腹痛，通常局限于右下腹，偶尔发烧、恶心、呕吐和腹泻。
● CT通常表现为卵形，异质性肿块，包含脂肪和软组织密度，通常在前腹壁和横结肠或升结肠之间。网膜梗塞通常为> 5 cm。
● 螺旋式肠系膜血管可以在由扭转引起的病例中可见(如肠扭转病例中所见的“旋转”信号)。
● Other Imaging Findings
● No Other Imaging Findings
● Pearls and Pitfalls
● Acute epiploic appendagitis may be a strong differential possibility in more subtle cases of omental infarction as it also represents fat necrosis.
● Acute epiploic appendagitis is more typically smaller, abuts the colon wall, contains a central dense focus within the fat, and is surrounded by a hyperdense ring.
● Omental infarction typically has no hyperdense rim in the acute stage but progressively develops one as it heals and reduces in size.
● Omental infarction is usually managed conservatively with pain control, so that the distinction from diverticulitis, neoplasm, and appendicitis is critical.
● 经验和教训
● 急性网膜附件炎可能是较轻微的网膜梗死的一种强烈差异可能性，也可以表示脂肪坏死。
● 急性网膜附件炎通常较小，与结肠壁相邻，在脂肪中包含中心致密密度，并被高密度环包围。
● 网膜梗死一般在急性期没有高密度边缘，但随着它的愈合和缩小而逐渐发展。
● 网膜梗死通常进行控制疼痛的保守治疗，因此，憩室炎、肿瘤和阑尾炎的区别是至关重要的。
● Further Readings
● Singh AK, Gervais DA, Lee P, et al. Omental infarct: CT imaging features. Abdom Imaging. 2006;31(5):549-554.