Intussusception; A to Z

Intussusception; A to Z Poster No.: C-0104 Congress: ECR 2014 Type: Educational Exhibit Authors: S. W. Shin, Y. Kim, E. T. Kim, M. Y. Kim ; Kuri city/kr, 1 1 2 1 1 2 Cheonan/KR Keywords: Gastrointestinal tract, Colon, Small bowel, CT, Ultrasound, Perception image, Surgery, Neoplasia, Pathology DOI: 10.1594/ecr2014/C-0104 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. www.myesr.org Page 1 of 26

Learning objectives 1. 2. To review the ultrasonography and CT findings of intussusception according to leading points, age and previous operation history. To know the ultrasonography and CT findings whether operation or not Background Intussusception is defined as the invagination of one segment of the gastrointestinal tract into an adjacent one. Diagnosis of intussusception is not complicated using ultrasonography and CT. Various leading points are present in the intussusception according to their age and previous operation history. We reviewed all types and age groups of intussusception. We divided into intussusception age groups as infants, children, and adult. And also we divided intussusception according leading points as follows; benign causes (mesenteric lymph nodes, appendicitis, lipoma, transient), malignant causes (colon cancer, metastasis), and post operative causes (adhesion band, bypassed intestinal segments, abnormal bowel motility, and intestinal tubes). Findings and procedure details Introduction Intussusception is the invagination of a bowel loop with its mesenteric fold (intussusceptum) into the lumen of a contiguous portion of bowel (intussuscipiens) as a result of peristalsis. After appendicitis, it is the second most common abdominal emergency in children and is idiopathic in 95% of cases. In contrast, intussusception in adults is rare, making up only about 1-5% of patients with bowel obstruction. Symptoms are often chronic, with intermittent abdominal pain being the main symptom. Unlike intussusception in children, an acute abdomen is a rare presentation in adults. An underlying pathological lead point or predisposing condition is frequently demonstrated and, consequently, non-operative reduction is not the treatment of choice in adults as it is in children. Pathogenesis, etiology and prevalence Page 2 of 26

Intussusception can be classified according to location (small bowel or colon) or according to the underlying etiology (neoplastic (benign or malignant), non-neoplastic or idiopathic). The exact mechanism is still unknown. However, it is believed that any lesion in the bowel wall or irritant within the lumen that alters normal peristaltic activity is able to initiate an invagination. Ingested food and subsequent peristaltic activity of the bowel produces an area of constriction above the stimulus and relaxation below, thus telescoping the lead point through the distal bowel lumen. About 80-90% of intussusceptions in adults are secondary to an underlying pathology, with approximately 65% due to benign or malignant neoplasm. Non-neoplastic processes constitute 15-25% of cases, while idiopathic or primary intussusceptions account for about 10%. Intussusception arises in the small bowel in two-thirds of cases. The etiology of intussusception in the small bowel and the colon is quite different. CT Appearance CT is the most effective and accurate diagnostic technique. Intussusception can be confidently diagnosed on CT because of its virtually pathognomonic appearance. It appears as a complex soft tissue mass (sausage-like or target-like appearance), consisting of the outer intussuscipiens and the central intussusceptum. There is often an eccentric area of fat density within the mass representing the intussuscepted mesenteric fat, and the mesenteric vessels are often visible within it. Recently, with the signs of target or sausage, mesenteric fat and vessels, abdominal CT scan has been reported to be the most useful imaging technique, with a diagnostic accuracy is 58%-100%. However, imaging modalities are limited in determining the primary cause of intussusception as well as in determining the presence or absence of ischemic injury at the involved bowel segment, which requires immediate surgery. Childhood Intussusception Most intussusceptions occur in children aged between 3 months and 3 years, with a male dominance of 3:2. It is secondary only to appendicitis as the most common cause of an acute abdominal emergency in children. In children, it typically presents with severe, colicky, intermittent abdominal pain, vomiting, diarrhea and "red currant jelly" stool, which is a manifestation of sloughed mucosa and blood. The classic triad of pain, red currant jelly stool and palpable mass is present in only 50% of cases, with as many as 20% being pain free at presentation. Page 3 of 26

Barium and contrast studies Traditionally, a contrast enema was considered the most reliable test for intussusception in children. Contrast enema, as well as being quick and effective, also has the potential to be therapeutic. The main risk of this procedure is perforation of the bowel resulting in barium peritonitis. The current practice is to use air as contrast, which is safer, cheaper and more effective. Perforation risk is also smaller with air. When performing a therapeutic enema, the recommended pressure of air insufflation should not exceed 120 cm of water. Air flow is continued until there is free reflux into the small bowel or until the intussusceptum is encountered. It is worthwhile to attempt pneumatic reduction if absolute contraindications (peritonitis and/or sepsis) are absent. The adoption of stricter exclusion criteria such as the presence of delayed diagnosis and raised neutrophils, even if strongly predictive of failure, may result in a substantial proportion of unnecessary laparotomy. Fig. 1: Six-year-old boy with ileocolic intussusception caused by mesenteric lymphadenitis. a. Transverse ultrasonography shows several enlarged mesenteric lymph nodes (arrowheads). b. Color Doppler ultrasonography shows engorged mesenteric vessels entered in the colon. c, d. Axial and coronal CT scan shows target lesion (arrows) in the right lower abdomen. e. Barium reduction shows a filling defect (arrow) within the bowel at the level of the ascending colon, represents the site of intussusceptum. f. After reduction barium material is demonstrated in the small bowel. References: Diagnostic Radiology, Hanyang University, Hanyang University Kuri Hospital - Kuri city/kr Page 4 of 26

Ultrasonography and CT Ultrasound is fast, non-invasive, easy to perform and reproducible. Classic findings on transverse scanning include a so-called "target lesion" or "doughnut sign", with the presence of several concentric rings. The inner hypoechoic ring is formed by the intussusceptum, with the outer ring representing the intussuscipiens and an intermediate hyper-echoic area indicating the space between. Imaging with computed tomography (CT) is normally not indicated in children, as the diagnosis is usually made evident by ultrasound or enema. It is however useful in adults in both making the diagnosis and assessing for an associated underlying cause and lead point. Fig. 2: Five-year-old boy with ileocolic intussusception caused by mesenteric lymphadenitis. a. Transverse ultrasonography shows several enlarged mesenteric lymph nodes (arrowheads). b. Transverse ultrasonography shows the classic "doughnut sign" of the concentric rings of intussusception (arrow). c-e. Venous phase of CT scan axial (c, d) and coronal (e) scans show a target lesion in the right lower abdomen with inner intussusceptum (open arrows) and outer intussuscipiens (arrows). f, g. Air reduction shows a soft tissue mass (arrows) representing an intussusception. References: Diagnostic Radiology, Hanyang University, Hanyang University Kuri Hospital - Kuri city/kr Transient intussusception Because of significant advancements in CT along with its increasing use, detection of enteroenteric intussusceptions by CT has increased. These findings are sometimes in asymptomatic patients, often transient, and without an identifiable lead point. Page 5 of 26

Small bowel intussusception without a lead point is more common than intussusception with a lead point. Intussusception without a lead point is known to appear as a nonobstructing segment, usually smaller in diameter and shorter, and less pericolic or perienteric infiltration than an intussusception with a lead point. Most enteroenteric lesions are nonsurgical lesions, whereas lesions that affect the colon are often surgical. Many nonsurgical enteroenteric intussusceptions are longer than 3.5 cm and thicker than 3 cm, suggesting these CT features may not be useful for diagnosing surgical bowel intussusceptions in adults. Correlating CT findings with the patients' clinical features remains imperative to facilitate the appropriate distinction of surgical from nonsurgical enteroenteric intussusceptions. Fig. 3: Four-year-old girl with vague abdominal pain. a-c. Axial CT scans show classic CT appearance of enteroenteric (jejunojejunal) intussusception (arrows). There is no evidence of obstruction, although small bowel was minimally dilated. d. Coronal reformatted CT scan shows invagination (arrows) of bowel and mesenteric vessels. References: Diagnostic Radiology, Hanyang University, Hanyang University Kuri Hospital - Kuri city/kr Page 6 of 26

Fig. 4: 26-year-old man with intermittent abdominal pain. a-c. Arterial phase of axial CT scans nicely show typical target appeared jejunojejunal intussusception (arrows). d, e. Venous phase of coronal reformatted CT images show short segment jejunojejunal intussusception (arrows). References: Diagnostic Radiology, Hanyang University, Hanyang University Kuri Hospital - Kuri city/kr Post operative intussusception Intussusception following abdominal surgery may be related to a variety of predisposing factors, including intestinal anastomotic suture lines, previous jejunostomy site, adhesions, submucosal bowel edema, intestinal dysmotility and electrolyte imbalance. Long intestinal tubes are known to cause telescoping of the bowel. Page 7 of 26

Fig. 5: 61-year-old woman with subtotal gastrectomy with gastrojejunostomy for 12 years ago due to gastric ulcer perforation. a. Axial CT scan shows fluid distension of subtotal gastrectomy (arrowheads) with gastrojejunostomy. b, c. Lower level of axial CT scans show invagination of proximal jejunum (arrow) into the distal jejunum. df. Coronal reformatted CT scan shows bizarre shaped jejunojejunal intussusception (arrows) with dilated proximal bowel loops. References: Diagnostic Radiology, Hanyang University, Hanyang University Kuri Hospital - Kuri city/kr Page 8 of 26

Fig. 6: Distal esophagectomy with esophagogastro-colonostomy 13 days ago due to esophageal perforation in a 40-year-old man. a. Interposition of colon (arrowhead) shows anterior side of left lobe of liver. b, c. Ring shaped mass (arrows) is seen in the mid abdomen, with a thick soft tissue density representing opposing bowel walls. Mesenteric vessels course within the central low density mesenteric fat (open arrow). d, e. Coronal CT scans show very long jejunojejunal intussusception (arrows) within the mesenteric vessels and fat. There is also noted dilated proximal bowel loops and ascites. References: Diagnostic Radiology, Hanyang University, Hanyang University Kuri Hospital - Kuri city/kr Page 9 of 26

Fig. 7: 57-year-old woman with feeding gastrostomy for 2 years ago due to cerebrovascular accident. a-c. Axial CT scans show the balloon tip of feeding gastrostomy tube (arrowhead) located in the 3rd portion of duodenum. Proximal jejunal loop (open arrows) retrograde invaginates into the duodenum resulting fluid filled stomach. d. Coronal reformatted CT scan shows retrograde jejunoduodenal intussusception (arrows). e. We immediately decompressed balloon of the tube. After four days, preenhance CT scan shows spontaneously reduction of intussusception. References: Diagnostic Radiology, Hanyang University, Hanyang University Kuri Hospital - Kuri city/kr Page 10 of 26

Fig. 8: After colon polypectomy, colocolic intussusception developed in a 77-yearold man. Pathologic diagnosis is submucosal edema in the ascending colon around polypectomy site. a-c. Axial CT scans show colocolic intussusception (arrows) with severe edematous bowel wall thickening and contrast enhancement of the mucosa and serosa. d-f. Coronal reformatted CT scans well demonstrates invagination of proximal colon loop (open arrows) into the distal ascending colon. References: Diagnostic Radiology, Hanyang University, Hanyang University Kuri Hospital - Kuri city/kr Small bowel intussception Most intussusceptions in the small bowel are secondary to benign lesions. These include benign neoplasms (lipoma, leiomyoma, haemangioma, neurofibroma), adhesions, Meckel's diverticulum, lymphoid hyperplasia and adenitis, trauma, coeliac disease, intestinal duplication and Henoch-Schonlein purpura. Malignant lesions causing intussusception in the small intestine account for about 6-30% of cases and are most often metastatic, melanoma being by far the most common metastasis to cause intussusception. Idiopathic intussusception accounts for about 8-20% of all small bowel intussusceptions. Fig. 9: Intussusception in a 69-year-old woman with partial small bowel obstruction caused by metastatic lung cancer. a-f. Venous phase of axial CT scans show multiple small bowel wall thickening and enteroenteric intussusceptions (arrows). Small bowel wall thickening represents metastasis of adenocarcinoma of lung cancer. References: Diagnostic Radiology, Hanyang University, Hanyang University Kuri Hospital - Kuri city/kr Page 11 of 26

Fig. 10: Multiple enteroenteric intussusception in a 31-year-old man with Peutz-Jegher syndrome. a-c. Axial CT scans show polypoid mass (arrowheads) in the tip of the enteroenteric intussusceptions (arrows). d, e. Coronal reformatted CT scans show two enteroenteric intussusception (arrows) with mildly dilated proximal bowel loop. f. Small bowel series shows jejunojejunal intussusception (arrow) without obstruction. g. Endoscopy shows polyp (arrowheads) in the duodenum. References: Diagnostic Radiology, Hanyang University, Hanyang University Kuri Hospital - Kuri city/kr Colon intussusception Intussusception in the large bowel is more likely to have a malignant etiology (50-60%). This reflects the greater prevalence of malignant tumors in the colon compared with the small bowel. Primary malignant lesions (adenocarcinoma and lymphoma) are the most common underlying malignant lesions in the colon. Benign lesions constitute about 30% and include neoplasm such as lipoma, leiomyoma, adenomatous polyp, endometriosis (appendiceal) and previous anastomosis. Idiopathic intussusception occurs less often than in the small bowel (about 10%). Page 12 of 26

Fig. 11: Ileocolic intussusception in a 41-year-old man with pulmonary and intestinal Tuberculosis. a-c. Axial CT scans show ileocolic intussusception (arrows) with irregular thickening of colon and ileal walls. d, e. Coronal reformatted CT scans show short segment of invagination of terminal ileum (open arrows) into the ascending colon. f, g. Chest CT scans show right chronic empyema (arrowheads) and multiple nodular infiltration in the lower lung result to Tuberculosis. References: Diagnostic Radiology, Hanyang University, Hanyang University Kuri Hospital - Kuri city/kr Lipoma While the appearance of intussusception is characteristic on CT, its etiology cannot usually be established. Exceptions are lipoma, a long intestinal tube and known abdominal metastatic disease. A lipoma serving as a lead point is identified as a mass of fat density that does not contain blood vessels. Mesenteric fat entrapped in an intussusception also has fat density but has blood vessels coursing through it, and can thus be distinguished from lipoma. Lipomas are the most common benign cause of colocolic intussusception in adults. Next to adenomatous polyps, these mesenchymal tumors are the most common benign tumors of the colon. Lipomas of the colon are within the submucosa in 90% of cases, are usually solitary, and may be sessile or pedunculated. Page 13 of 26

Fig. 12: Colocolic intussusception caused by a lipoma as a lead point in a 44-yearold man. a-d. Axial CT scans show a round hypodence mass (arrows) in the tip of the intussusception. The fat density is homogeneous, characteristic of a lipoma. e. Coronal reformatted CT scan represents intussusception as a lead point of lipoma (arrow). References: Diagnostic Radiology, Hanyang University, Hanyang University Kuri Hospital - Kuri city/kr Adenocarcinoma Adenocarcinoma of the colon is the most common malignant neoplasm associated with colonic intussusception. Typical signs and symptoms of adenocarcinoma of the colon include bleeding, obstruction, a palpable abdominal mass, and abdominal pain. The individual layers of the intussuscepted bowel wall are more easily distinguished from the lead mass in this intussusception. Page 14 of 26

Fig. 13: Colocolic intussusception secondary to adenocarcinoma in a 72-year-old woman. a-c. Axial CT scans show the typical findings of intussusception (arrows) with engorgement of ileocolic vessels (open arrows). d-f. Coronal reformatted CT scans well demonstrate colon mass (arrowheads) which was proven adenocarcinoma by pathologic diagnosis. References: Diagnostic Radiology, Hanyang University, Hanyang University Kuri Hospital - Kuri city/kr Images for this section: Page 15 of 26

Fig. 1: Six-year-old boy with ileocolic intussusception caused by mesenteric lymphadenitis. a. Transverse ultrasonography shows several enlarged mesenteric lymph nodes (arrowheads). b. Color Doppler ultrasonography shows engorged mesenteric vessels entered in the colon. c, d. Axial and coronal CT scan shows target lesion (arrows) in the right lower abdomen. e. Barium reduction shows a filling defect (arrow) within the bowel at the level of the ascending colon, represents the site of intussusceptum. f. After reduction barium material is demonstrated in the small bowel. Fig. 2: Five-year-old boy with ileocolic intussusception caused by mesenteric lymphadenitis. a. Transverse ultrasonography shows several enlarged mesenteric lymph nodes (arrowheads). b. Transverse ultrasonography shows the classic "doughnut sign" of the concentric rings of intussusception (arrow). c-e. Venous phase of CT scan axial (c, d) and coronal (e) scans show a target lesion in the right lower abdomen with inner intussusceptum (open arrows) and outer intussuscipiens (arrows). f, g. Air reduction shows a soft tissue mass (arrows) representing an intussusception. Page 16 of 26

Fig. 3: Four-year-old girl with vague abdominal pain. a-c. Axial CT scans show classic CT appearance of enteroenteric (jejunojejunal) intussusception (arrows). There is no evidence of obstruction, although small bowel was minimally dilated. d. Coronal reformatted CT scan shows invagination (arrows) of bowel and mesenteric vessels. Page 17 of 26

Fig. 4: 26-year-old man with intermittent abdominal pain. a-c. Arterial phase of axial CT scans nicely show typical target appeared jejunojejunal intussusception (arrows). d, e. Venous phase of coronal reformatted CT images show short segment jejunojejunal intussusception (arrows). Fig. 5: 61-year-old woman with subtotal gastrectomy with gastrojejunostomy for 12 years ago due to gastric ulcer perforation. a. Axial CT scan shows fluid distension of subtotal gastrectomy (arrowheads) with gastrojejunostomy. b, c. Lower level of axial CT scans show invagination of proximal jejunum (arrow) into the distal jejunum. d-f. Coronal Page 18 of 26

reformatted CT scan shows bizarre shaped jejunojejunal intussusception (arrows) with dilated proximal bowel loops. Fig. 6: Distal esophagectomy with esophagogastro-colonostomy 13 days ago due to esophageal perforation in a 40-year-old man. a. Interposition of colon (arrowhead) shows anterior side of left lobe of liver. b, c. Ring shaped mass (arrows) is seen in the mid abdomen, with a thick soft tissue density representing opposing bowel walls. Mesenteric vessels course within the central low density mesenteric fat (open arrow). d, e. Coronal CT scans show very long jejunojejunal intussusception (arrows) within the mesenteric vessels and fat. There is also noted dilated proximal bowel loops and ascites. Page 19 of 26

Fig. 7: 57-year-old woman with feeding gastrostomy for 2 years ago due to cerebrovascular accident. a-c. Axial CT scans show the balloon tip of feeding gastrostomy tube (arrowhead) located in the 3rd portion of duodenum. Proximal jejunal loop (open arrows) retrograde invaginates into the duodenum resulting fluid filled stomach. d. Coronal reformatted CT scan shows retrograde jejunoduodenal intussusception (arrows). e. We immediately decompressed balloon of the tube. After four days, preenhance CT scan shows spontaneously reduction of intussusception. Fig. 8: After colon polypectomy, colocolic intussusception developed in a 77-yearold man. Pathologic diagnosis is submucosal edema in the ascending colon around polypectomy site. a-c. Axial CT scans show colocolic intussusception (arrows) with Page 20 of 26

severe edematous bowel wall thickening and contrast enhancement of the mucosa and serosa. d-f. Coronal reformatted CT scans well demonstrates invagination of proximal colon loop (open arrows) into the distal ascending colon. Fig. 9: Intussusception in a 69-year-old woman with partial small bowel obstruction caused by metastatic lung cancer. a-f. Venous phase of axial CT scans show multiple small bowel wall thickening and enteroenteric intussusceptions (arrows). Small bowel wall thickening represents metastasis of adenocarcinoma of lung cancer. Page 21 of 26

Fig. 10: Multiple enteroenteric intussusception in a 31-year-old man with Peutz-Jegher syndrome. a-c. Axial CT scans show polypoid mass (arrowheads) in the tip of the enteroenteric intussusceptions (arrows). d, e. Coronal reformatted CT scans show two enteroenteric intussusception (arrows) with mildly dilated proximal bowel loop. f. Small bowel series shows jejunojejunal intussusception (arrow) without obstruction. g. Endoscopy shows polyp (arrowheads) in the duodenum. Fig. 11: Ileocolic intussusception in a 41-year-old man with pulmonary and intestinal Tuberculosis. a-c. Axial CT scans show ileocolic intussusception (arrows) with irregular thickening of colon and ileal walls. d, e. Coronal reformatted CT scans show short segment of invagination of terminal ileum (open arrows) into the ascending colon. f, g. Chest CT scans show right chronic empyema (arrowheads) and multiple nodular infiltration in the lower lung result to Tuberculosis. Page 22 of 26

Fig. 12: Colocolic intussusception caused by a lipoma as a lead point in a 44-yearold man. a-d. Axial CT scans show a round hypodence mass (arrows) in the tip of the intussusception. The fat density is homogeneous, characteristic of a lipoma. e. Coronal reformatted CT scan represents intussusception as a lead point of lipoma (arrow). Fig. 13: Colocolic intussusception secondary to adenocarcinoma in a 72-year-old woman. a-c. Axial CT scans show the typical findings of intussusception (arrows) with engorgement of ileocolic vessels (open arrows). d-f. Coronal reformatted CT scans well Page 23 of 26

demonstrate colon mass (arrowheads) which was proven adenocarcinoma by pathologic diagnosis. Page 24 of 26

Conclusion There are major differences in the incidence, pathogenesis, imaging stratification and management of intussusception between the pediatric and adult populations. In the pediatric group, intussusception is far more common and the etiology is generally benign. In addition, in this age group ultrasonography is highly sensitive and specific in experienced hands and initial treatment is often by radiological reduction. Adult intussusception is an infrequent problem. Most adult intussusceptions present with subacute and chronic symptoms have intestinal obstructions to various extents. CT is the most effective and accurate diagnostic technique. In the case of a palpable abdominal mass, ultrasonography is also helpful for diagnosis. Barium studies and ultrasound are still important in the imaging of intussusception, particularly in children. In adults, CT plays a more important role in the detection and evaluation of intussusception, aiding surgical planning and, in some cases, demonstrating an associated underlying cause. Personal information Corresponding Author: Yongsoo Kim, M.D., Ph.D. Affiliation: Department of Radiology, Hanyang University Kuri Hospital Address: 249-1 Kyomoondong, KuriCity, Kyunggido, South Korea, 471-701 Email address: ysookim@hanyang.ac.kr References 1. 2. 3. 4. Gayer G, Zissin R, Apter S, Papa M, Hertz M. Adult intussusception-a CT diagnosis. Br J Radiol, 2002;75:185-190 Kim YH, Blake MA, Harisinghani MG, et al. Adult Intestinal Intussusception: CT Appearances and Identification of a Causative Lead Point. Radiograph 2006;26:733-744 Tresoldi S, Kim YH, Bladke MA, et al. Adult intestinal intussusception: can abdominal MDCT distinguish an intussusception caused by a lead point? Abdom Imaging 2008;33:582-588 Wang N, Cui XY, Liu Y, Long J, Xu YH, Guo RX, Guo KJ. Adult intussusception: A retrospective review of 41 cases. World J Gastroenterol 2009;15(26):3303-3308 Page 25 of 26

5. Sundaram B, Miller CN, Cohan RH, Schipper MJ, Francis IR. Can CT Features Be Used to Diagnose Surgical Adult Bowel Intussusceptions? AJR 2009;193:471-478 6. Park SB, Ha HK, Kim AY, et al. The diagnostic role of abdominal CT imaging findings in adults intussusception: Focused on the vascular compromise. Euro J Radiol 2007;62:406-415 7. Byrne AT, Goeghegan T, Govender P, Lyburn ID, Colhoun E, Torreggiani WC. The imaging of intussusception. Clin Radiol 2005;60:39-46 8. Fragoso AC, Campos M, Tavares C, Costa-Pereira A, Estevão-Costa J, Pneumatic reduction of childhood intussusception. Is prediction of failure important? J Ped Surg 2007;42:1504-1508 9. Lvoff N, Breiman RS, Coakley FV, Lu Y, Warren RS. Distinguishing features of self-limiting adult small bowel intussusception indentified at CT. Radiol 2003;227:68-72 10. Horton KM, Fishman EK. MDCT and 3D Imaging in Transient Enteroenteric Intussusception: Clinical Observations and Review of the Literature. AJR 2008;191:736-742 Page 26 of 26