Evaluation of Small Bowel Obstruction Using

J Korean Radiol Soc 2008;58:283-295

Evaluation of Small Bowel Obstruction Using Multidetector Computed Tomography (MDCT)1 Jee Hye Lee, M.D., Soon-Young Song, M.D., On Koo Cho, M.D., Byung Hee Koh, M.D., Yongsoo Kim, M.D.2

Small bowel obstruction is a relatively common clinical condition and its diagnosis is based on the clinical signs, the patient’s history and the radiologic findings. For a patient with suspected small bowel obstruction, it is essential to determine the site, location and cause of obstruction for the appropriate management. Because of the poor accuracy of plain radiography, computed tomography (CT) now has an essential role to diagnose bowel obstruction. With the recent evolution of conventional CT into multidetector computed tomography (MDCT), it is possible to obtain cross sectional images with high spatial resolution and different post-processes can be done, such as obtain- ing the volume rendering (VR), maximum intensity projection (MIP), or multiplanar reformatted (MPR) images from the volume data. In this article, we illustrate and discuss the utility of the multiplanar images of MDCT for diagnosing the sites, causes and complications of small bowel obstruction.

Index words : Intestine, small intestinal obstruction Tomography, spiral computed, multi-detector Multiplanar images Imaging, three-dimensional

Although plane radiography is the first step for mak- sional imaging technique, it is possible to reconstruct the ing the diagnosis of small bowel obstruction, its accura- VR, MIP or MPR images from the volume data. In this cy for determining the presence of obstruction is only article, we illustrate and discuss the usefulness of the 46-80% (1-7). CT currently has an essential role in di- multiplanar MDCT images for diagnosing the site of agnosing small bowel obstruction. It has a high sensitivi- bowel obstruction and characterizing the specific causes ty of 94%-100% and an accuracy of 90%-95% (1, 3, 8). of small bowel obstruction. In addition, we also illus- In addition, the recent evolution of conventional CT into trate the findings of complicated loops due to small bow- MDCT has brought about great advances in the evalua- el obstruction. tion of the small bowel. With the use of the 3-dimen- Scan parameters of the MDCT Examination 1Department of Radiology, Hanyang University College of Medicine, Hanyang University Hospital, Korea A 16-detector row spiral CT scanner (Sensation 16; 2Department of Radiology, Hanyang University College of Medicine, Hanyang University Kuri Hospital, Korea Siemens Medical Systems, Erlangen, Germany) with a Received September 13, 2007 ; Accepted November 1, 2007 gantry rotation time of 0.5 seconds was used at our insti- Address reprint requests to : Soon-Young Song, M.D., Department of Radiology, Hanyang University College of Medicine, Hanyang University tute for the abdominal examinations. All the patients Hospital, 17 Haengdang-dong, Seongdong-gu, Seoul 133-792, Korea were placed in the supine position on the CT table. The Tel. 82-2-2290-9160 Fax. 82-2-2293-2111 E-mail: [email protected] acquisition volume included the whole abdomen from ─ 283 ─ Jee Hye Lee, et al : Evaluation of Small Bowel Obstruction Using Multidetector Comp uted Tomography (MDCT) the dome of the diaphragm to the lower margin of the CT scan for the hepatic arterial-phase images was start- symphysis pubis. An 18-gauge intravenous cannula was ed 8 seconds after the attenuation reached 150 H.U. An inserted into a vein in the antecubital fossa, forearm or additional CT scan for the portal-phase images was start- wrist. Scanning of the abdomen was performed after in- ed 60 seconds after starting the contrast injection. The travenously injecting 2 mg/kg of contrast medium (io- CT scan was done during a breath holding at the end of promide [Ultravist 370]; Schering, Berlin, Germany) inspiration. The CT examination was performed by us- with an automatic power injector at a flow rate of 2.5- ing 16×1.5-mm collimation and a table feed rate of of 3.0 mL/sec. for a total of 100-120 mL. The scan delay 24 mm per gantry rotation. The X-ray tube voltage was time was determined by the automatic bolus tracking 120 kV and amperage was 140 mAs. The volume data of method. The region of interest (R.O.I.) was positioned at both the arterial and portal-phased scans was recon- the descending aorta at the level of the diaphragm. The structed at a 2-mm thickness and with a 1-mm interval.

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C D Fig. 1. A-D. Small bowel perforation in a 50 year-old male patient with advanced Crohn’s disease. A. The axial CT scan shows marked dilatation of the small bowel loops and multifocal mural thickening. There are multiple foci of extraluminal air suggesting intestinal perforation (not seen). An abrupt change of caliber is noted (arrow). B, C. The coronal reformatted images also easily demonstrate the site of obstruction with an abrupt change of caliber (arrow). Multifocal extraluminal air bubbles are noted in the peritoneal cavity. There is a well-demonstrated site of perforation (arrowhead). D. The gross specimen shows strangulated bowel loops and the site of perforation (arrowhead). ─ 284 ─ J Korean Radiol Soc 2008;58:283-295

Image Interpretation Intrinsic Causes

The volume data of the whole abdomen was acquired Inflammatory diseases during a single breath hold for all the patients who un- Crohn’s disease derwent abdominal CT for the evaluation of small bow- Crohn’s disease is an idiopathic inflammatory disease el obstruction. The axial images of both the portal and that can affect any part of the gastrointestinal tract from arterial phases and the coronal image of the arterial the mouth to the anus. The small bowel is the major site phase were reformatted for routine study. We acquired of involvement. Small bowel wall thickening and lumi- additional MPR images at various angles and the curved nal narrowing may be the common findings. The in- MPR images from the volume data with using PC-based flamed mucosa and serosa may be markedly enhanced, 3-dimensional software (Rapidia 2.8; InfinitⓇ, Seoul, and the intensity of enhancement correlates with the Korea). clinical activity of the disease. Mural stratification disap- pears during the chronic phase, so that the affected bow- Classifying the Causes of Small Bowel Obstruction el wall typically has homogeneous attenuation at CT (2, 9). In the advanced or stenotic phase of Crohn’s disease, The causes of small bowel obstruction can be classi- the patients frequently present with recurrent episodes fied in two major categories, that is, the intrinsic and ex- of partial small bowel obstruction associated with stric- trinsic causes. The intrinsic causes include inflammato- ture. Dilated small bowel loops with an abrupt change ry disease and neoplastic disease. Other conditions such in caliber can be detected on the routine axial CT images as an intraluminal bezoar or a foreign body can also (Fig. 1A) (2). The reformatted images can demonstrate cause obstruction. The extrinsic extraluminal patholo- the full-length of the obstruction site (Fig. 1B). Severe gies can result in small bowel obstruction. Adhesion and obstruction can sometimes lead to perforation of the hernia are seen frequently. Although other conditions small bowel, which requires emergency surgical inter- such as superior mesenteric artery (SMA) syndrome are vention (Fig. 1C). MDCT may be a useful tool not only infrequent, it can be a cause of duodenal obstruction. for diagnosing the level and cause of obstruction, but al- Complicated cases such as strangulation, closed loop ob- so for detecting the site of perforation (Fig. 1A to 1D). struction and afferent loop syndrome are classified in the third category of the complicated small bowel ob- Intestinal tuberculosis struction. Even though Mycobacterium tuberculosis can involve any part of the gastrointestinal tract, the ileocecal region

A B C Fig. 2. A-C. Intestinal tuberculosis with focal stricture in a 65 year-old female patient. A, B. The slab VR images of CT shows a dilated jejunal loop, and note the abrupt change of caliber (arrow). C. The curved MPR image shows focal bowel wall thickening that is suggestive of inflammatory lesion (arrowhead). ─ 285 ─ Jee Hye Lee, et al : Evaluation of Small Bowel Obstruction Using Multidetector Comp uted Tomography (MDCT) is the most common site of involvement for tuberculosis bowel disease with the advantage of an overlap-free dis- of the gastrointestinal tract. Intestinal tuberculosis may play of such individual structures as the bowel, vessels cause stricture of the small bowel and subsequent ob- and solid organs. The images of the small bowel can be struction. The gross morphologic features of this patho- reconstructed in a pattern resembling enteroclysis and logic process have been well evaluated with CT (9). this makes the pathologic segment more easily de- When the inflammation is mild, CT demonstrates only tectible (Fig. 2A to 2C). slight, symmetric mural thickening and a few small re- gional nodes. When the pathologic process is severe and Parasitic infestation advanced, then the more characteristic abnormalities Parasites can be a rare intrinsic inflammatory cause of are evident. Characteristically, the CT findings include small bowel obstruction. The possible organisms that asymmetric thickening of the ileocecal valve and the can infest the bowel are Ascaris lumbricoides, hook- medial wall of the cecum, with an exophytic extension worm (Ancylostoma duodenale and Necator ameri- that engulfs the terminal ileum. Massive lym- canus), tapeworm (Diphyllobothrium latum, Taenia phadenopathy can be combined with this, and the lym- solium), Strongyloides stercoralis, Giardia lamblia and phadenopathy shows central areas of low attenuation the Anisakis species. When adult Ascaris are present in (10, 11). The cecum becomes conical, shrunken and re- large numbers, they may form an intertwined bolus, tracted out of the iliac fossa due to fibrosis within the causing intestinal obstruction (14). mesocolon (12). Symmetric annular stenosis and ob- Nematodes of the Anisakis genera inhabit the intesti- struction associated with shortening, retraction and nal tracts of marine mammals and piscivorous birds. pouch formation may be seen (Fig. 2A and 2C) (13). Humans are infected by eating raw or insufficiently Using MDCT, the 3D data sets with using the volume cooked fish or squid. Several types of lesions can be pro- rendering technique can be applied for the evaluation of duced by the Anisakis larvae that have burrowed into

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Fig. 3. A-C. Small bowel obstruction due to anisakiasis in a 28 year-old male. A. An axial CT scan shows focal wall thickening of the ileal loop (arrow). B. The curved MPR image shows focal concentric wall thickening at the site of obstruction (arrow). C. The surgical specimen excised from the site of obstruction shows inflamed mucosa. There is a larva of the Anisakis species (arrow).

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the wall of the intestine. Ulcers, abscesses, eosinophilic physician arriving at a specific diagnosis. granuloma and perforations are possible findings. CT may reveal bowel wall thickening, mucosal edema, Neoplastic Diseases stricture and occasionally an inflammatory mass effect Small bowel neoplasms are another rare cause of ob- and all this can be a cause of small bowel obstruction struction. Adenocarcinoma of the small bowel is seen (Fig. 3A to 3C) (15, 16). Ascites may accompany the in- more frequently in the duodenum and proximal je- testinal changes. junum than in the ileum (18, 19). Tumor is usually de- The curved multi-planar reformatted images are ex- tected at an advanced stage. Small bowel obstruction tracted by defining a path on the key images. It is possi- secondary to adenocarcinoma usually manifests on CT ble to visualize the whole length of the pathologic bowel as mural thickening with abrupt luminal narrowing at segment and the exact location of obstruction in a single the transition zone. Usually only a short segment is in- image (Fig. 3B). volved. CT may provide unique information about tumor extension and local or distant metastases (Fig. 4A to Non-specific inflammation 4C). The oblique MPR image can be reformatted when Other than Crohn’s disease or tuberculosis, there are the reviewers rotate the basic axial, coronal and sagittal non-specific inflammatory conditions that may involve images in the 3D program. Using this easy technique, the small bowel and cause obstruction, and the cause or the pathologic bowel segment can be demonstrated pathogen is not usually recognized (2). This may resolve along its axis (Fig. 4B). spontaneously with conservative care and without the Other types of small bowel neoplasm, such as lipoma,

B Fig. 4. A-C. Small bowel obstruction due to jejunal adenocarcinoma in a 59 year old male patient. A. The axial CT scan shows an abrupt caliber change of the dilated small bowel loop (arrow). B. The curved MPR image shows the site of obstruction with an abrupt caliber change. The narrowed segment shows focal ec- centric wall thickening, suggesting the possibility of malignancy (arrow). C. The cut surface shows short segmental stricture of the small bowel with irregular mucosal thickening, which was confirmed as adenocarcinoma (arrow).

C ─ 287 ─ Jee Hye Lee, et al : Evaluation of Small Bowel Obstruction Using Multidetector Comp uted Tomography (MDCT) can also be a cause of small bowel obstruction due to the The obstruction caused by small bowel phytobezoars resulting intussusception. The lipoma and subsequent frequently occurs in the jejunum or proximal ileum (22). intussusception can be easily diagnosed on CT (20). CT has become a useful method for diagnosing the pres- Submucosal tumors such as lymphoma or gastrointen- ence and cause of small bowel obstruction in this set- stinal stromal tumor rarely cause small bowel obstructing. The CT findings for obstruction due to bezoars in- tion. clude a gas-containing intraluminal mass in the transition zone that causes obstruction (Fig. 5A to 5D). In typi- Other Intrinsic Causes cal cases, the luminal obstructing mass has a mottled ap- Bezoar pearance that’s outlined by fluid attenuation and this is Bezoars are an unusual cause of an acute abdomen similar to the small bowel feces sign (Fig. 5A and 5B) (1, due to small bowel obstruction. The number of cases of 23). bezoars has increased since the introduction of gastric surgery for treating gastroduodenal peptic ulcer or gas- Foreign body tric cancer (21). Complete mechanical bowel obstruction Incidentally ingested foreign material or an artificial is the most frequent clinical manifestation of bezoars. device can be a cause of bowel obstruction (24). Foreign

A B

C D Fig. 5. A-D. Bezoar in the duodenum causing duodenal obstruction in a 66 year-old female patient. A. The axial CT scan-coronal reformatted image shows material containing mottled gas in the dilated duodenal lumen (arrow). B. The coronal reformatted image shows intraluminal food material that contains mottled gas, and this has a mass effect in the 3rd and 4th portions of the duodenum (arrow), suggesting possibility of a bezoar. C. Barium study of the duodenum shows a large filling defect in the 4th portion of the duodenum (arrow). D. Gastrofiberscopy demonstrates the bezoar. ─ 288 ─ J Korean Radiol Soc 2008;58:283-295 bodies may pass smoothly through the bowel, but they gastrointestinal stricture can migrate to the distal part of can also directly obstruct a bowel segment (2). the bowel and cause subsequent bowel obstruction. On Intraluminal devices such as a stent placed in malignant MDCT, the curved MPR image can demonstrate the di-

B Fig. 6. A-C. Migrated stent in the terminal ileum in a 59 year-old female patient. A. The axial CT scan shows dilated ileal loops and an intraluminal metallic device, which is the distally migrated stent. B. The oblique MPR image shows the full-length of the stent in the distal portion of the obstructed loop. C. The curved MPR image shows thickening of the ileal wall at the distal end of the stent (arrow).

A B C Fig. 7. A-C. Small bowel obstruction due to adhesion with closed loop obstruction and strangulation in a 56 year old female patient with a history of transabdominal hysterectomy. A. Axial CT scan shows markedly dilated small bowel loops, which suggest small bowel obstruction. The degree of contrast enhancement of the bowel wall is decreased. B. The oblique axial image demonstrate an abrupt change of caliber and the beak appearance of two small bowel loops (arrow), which is the site of the adhesion. The narrow segments are pointing toward a single spot, suggesting closed loop obstruction. C. The coronal image shows the markedly decreased contrast enhancement of the dilated small bowel loops and a large amount of ascites. These findings suggest strangulation of the loops. The narrow segments are pointing toward a single spot, suggesting closed loop obstruction (arrowhead). ─ 289 ─ Jee Hye Lee, et al : Evaluation of Small Bowel Obstruction Using Multidetector Comp uted Tomography (MDCT) rect relationship between the foreign body and the bow- to congenital or unexplained causes. The CT findings el change with proximal obstruction (Fig. 6A to 6C). are abrupt change of the luminal caliber at the distal portion of the dilated small bowel loops. A sharp, Extrinsic Causes straight or slightly curved edge can be seen where the band crosses the bowel lumen (Fig. 7A to 7C) (2). All Adhesions other possible causes of obstruction should be excluded There are adhesions in more than 90% of patients who on CT (1). have undergone laparotomy even one time. Adhesions may exist in either the area of surgical intervention or at Hernia the undersurface of the abdomen (25). Adhesive bands Internal Hernia are formed by fibrin deposition and fibrinous adherence Internal hernia is a rare cause of small-bowel obstruc- between the intraperitoneal surfaces that are stimulated tion, with a reported incidence of 0.2%-0.9% (27). by trauma or ischemia (26). However, symptoms are These hernias may be either congenital or acquired. produced only in a few cases. Adhesions are responsible This condition involves herniation of a viscus, usually for at least 60% of the cases of small bowel obstruction; the small bowel, through a normal or abnormal aperture more than 80% of these lesions occur after surgery, 15% within the peritoneal cavity. This herniation may be are due to inflammation and the remaining 5% are due persistent or intermittent. Because of the risk of strangu-

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Fig. 8. A-C. Left paraduodenal hernia presenting in a 54 year-old male patient with vomiting symptoms A. The axial CT scan shows clustered small bowel loops between the stomach and pancreas. The inferior mesenteric vessel is displaced to the left and it is located at the anterior aspect of the hernial sac (arrowhead). B. The coronal MPR image clearly demonstrates the hernial sac (arrows). C. Barium study of the small bowel shows clustered proximal jejunal loops in the left upper abdomen (arrow).

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lation of the hernia contents, even small internal hernias tor and sciatic hernias. The inguinal hernias are usually are dangerous and they can be lethal. an indirect type. Overall, the indirect inguinal hernias More than 50% of the internal hernias reported in the are the most common abdominal wall hernias. Indirect radiology and surgery literature have been paraduode- inguinal hernias account for 15% of all intestinal ob- nal (28). The opening into the left paraduodenal hernial struction (30). CT examination can provide useful diag- sac is known as the fossa of Landzert and it contains the nostic information of the hernia’s contents and its differ- inferior mesenteric vein and left colic artery in its anteri- entiation from other masses involving the groin or scro- or edge. The opening into the right paraduodenal her- tum (Fig. 9A to 9B). In cases of strangulated hernia, a nial sac is known as the fossa of Waldeyer and it con- compromised blood supply is present that can cause tains the superior mesenteric vessels in its anterior edge. thickening of the bowel loops. Adjacent inflammatory On CT, the encapsulated bowel loops are seen either at changes can be seen on CT in association with small the dudodenal junction between the stomach and pan- bowel obstruction. The herniation occurs into the scro- creas to the left of the ligament of Treitz, which is be- tal sac along the long axis of the body, although to view hind the pancreatic tail itself, and this displaces the infe- this it is very helpful to reformat the images in the coro- rior mesenteric vein to the anterior left or between the nal or sagittal plane (Fig. 9B). transverse colon and the left adrenal gland (Fig. 8A to Obturator hernia is relatively rare. It occurs through 8C) (27). the obturator canal, adjacent to the obturator vessels The other types of internal hernia that have been de- and nerve. The reported incidence of obturator hernia scribed include transmesenteric hernia, supra- and/or ranges from 0.05% to 1.5% of all hernias (31). Because perivesical hernia, intersigmoid hernia, foramen of of its anatomical position, this hernia more commonly Winslow hernia, and on rare occasions omental hernia. presents as a bowel obstruction than as a protrusion of bowel contents. It can be easily diagnosed on MDCT External Hernia with the MPR images, and the hernial sac is seen as a Hernia through the walls of the abdominal cavity de- fluid filled mass or bowel loop extending between the velops in approximately 1.5% of the population and this pectineus and obturator muscles (Fig. 10A, B) (32). usually involves specific sites of congenital weakness or previous surgical incision (27, 29). CT is useful for de- Other extrinsic causes picting the precise sites and the types of hernia and the SMA Syndrome contents. Among them, 75% of all abdominal hernias SMA syndrome is an uncommon, but well recognized occur in the groin. These are inguinal, femoral, obtura- clinical entity that’s characterized by compression of the

A Fig. 9. A, B. Right inguinal hernia in a 63 year-old male patient. A. The axial CT scan shows a small bowel loop and mesenteric fat in the right scrotal sac. The inferior mesenteric vein is displaced to the left and it is located at the anterior aspect of the hernial sac (arrowhead). B. The oblique MPR image exclusively demonstrates a large peritoneal defect and herniation of the segmental ileal loop along the inguinal canal into the scrotal sac. Fluid density is seen below the herniated loop. B ─ 291 ─ Jee Hye Lee, et al : Evaluation of Small Bowel Obstruction Using Multidetector Comp uted Tomography (MDCT) third or transverse portion of the duodenum against the aorta by the SMA, resulting in chronic, intermittent or Complicated small bowel obstruction acute complete or partial duodenal obstruction (33, 34). The MPR images can directly demonstrate the duodenal Strangulation obstruction and distension and they can delineate the di- The reported prevalence of strangulating small bowel agnostic findings of a decreased aortomesenteric angle obstruction ranges from 5% to 42% and its mortality and distance (Fig. 11A and 11B). The aortomesenteric rate ranges from 20% to 37% (35, 36). Strangulation is angle is 45 degrees with a range between 33 and 60 de- associated with adhesions and internal or external her- grees. In patients with SMA syndrome, the angle is nias. The CT findings include evidence of small bowel sharply decreased, ranging from 6 to 25 degrees (Fig. obstruction, a circumferentially thickened loop with 11B). high attenuation within the wall, the “target sign,” and congestion or hemorrhage in the mesentery attached to the closed loop (Fig. 7A to 7C). Pneumatosis intestinalis

A B Fig. 10. A, B. Intestinal obstruction due to obturator hernia in an 82 year-old female patient. A. The axial image shows a fluid-filled round structure between the pectineus and obturator muscles (arrow). B. The curved MPR image demonstrates a short segment of herniated bowel loop and dilatation of the proximal bowel, suggesting mechanical obstruction due to obturator hernia (arrow).

A Fig. 11. A, B. Proximal duodenal obstruction associated with superior mesenteric artery syndrome in a 34 year-old male patient. A. The axial CT scan shows dilatation of the second portion of the duodenum with a compressed third portion between the aorta and superior mesenteric artery (ar- B row). B. The oblique MPR image shows a compressed duodenal loop (arrow) in the narrowed aortomesenteric angle (14 degrees). ─ 292 ─ J Korean Radiol Soc 2008;58:283-295

may develop in advanced cases. Although ascites may site of obstruction, the collapsed loops are round, oval or be present in patients with closed loop obstruction with- triangular (Fig. 7A to 7C). The “beak sign” seen at the out ischemia or with simple bowel obstruction, it is site of torsion appears as a fusiform tapering on the lon- more commonly seen in patients with strangulation and gitudinal bowel imaging (Fig. 7B and 7C) (37). A tightly this should be considered as a suspicious finding. twisted mesentery is occasionally seen in patients with volvulus and this has been described as the “whirl sign” Closed Loop Obstruction (38). Multiplanar reformation can provide easier visual- A closed or incarcerated small bowel loop is a form of ization of these specific findings. mechanical obstruction in which a segment of bowel is occluded at two points along its course by a single con- Afferent loop syndrome strictive lesion occluding both the small bowel and Afferent loop obstruction is an uncommon complica- mesentery. The closed loop is able to rotate along its ax- tion that occurs in 0.3% of the patients that have under- is, thereby producing a small bowel volvulus. The CT gone subtotal gastrectomy with Billroth II gastrojejunos- findings in closed-loop obstruction depend on its length tomy (38). The causes include internal hernias, kinking and the degree of distention and the orientation of the of the anastomosis, adhesive bands, stomal stenosis, closed loop in the abdomen (8). When a closed small neoplasm and inflammatory disease. The abdominal ra- bowel loop is horizontally oriented, it has a U- or C- diographs are often normal because the afferent loop is shaped configuration on the cross-sectional imaging. A fluid-filled as a result of distal obstruction. CT allows di- radial configuration with stretched mesenteric vessels rect visualization of the obstructed afferent loop. The converging toward the site of torsion may be detected fluid-filled, dilated afferent portion of the jejunum can depending on the orientation of the different small bow- be easily identified (39) (Fig. 12A to 12C). With use of el loops within the incarcerated bowel segment. At the the curved MPR images, the cause of afferent loop syn-

Fig. 12. A-C. Afferent loop syndrome after subtotal gastrectomy with gastrojejunostomy in a 47 year-old male patient. A. The initial simple abdominal radiography demonstrates no specific ab- normality. B. The coronal MPR image shows the fluid-filled, dilated duodenum in the upper abdomen. C. The curved MPR image shows a to- tally fluid-filled duodenum and proximal jejunum connected to the rem- nant stomach. There is focal wall thickening of the gastrojejunostomy site (arrow), which is the cause of the afferent loop obstruction.

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대한영상의학회지 2008;58:283-295

다중검출기CT를 이용한 소장폐쇄평가1

1한양대학교 의과대학, 한양대학병원 영상의학과 2한양대학교 의과대학, 한양대학교 구리병원 영상의학과

이지혜·송순영·조온구·고병희·김용수 2

소장폐쇄는 임상에서 흔히 접하며 그 진단은 임상증상과 환자의 과거력, 영상의학 소견을 종합하여 내리게 된다. 소장폐쇄가 의심되는 환자에서 폐쇄부위와 원인결정은 적절한 치료의 기본이다. 영상검사로 복부단순촬영을 흔히 시행하지만 그 정확도가 낮아 복부전산화단층촬영(CT)을 소장폐쇄의 진단에 필수검사로 시행하고 있다. 최근 다중 검출기전산화단층촬영기(MDCT)가 많이 보급되어 고해상도의 단면영상을 얻을 수 있고 삼차원영상프로그램을 통 한 영상의 다면재구성이 가능해졌다. 이 종설에서는 소장폐쇄의 원인, 부위, 및 이들과 동반된 합병증진단에 MDCT 검사와 다양한 삼차원재구성영상의 유용성을 기술하고자 한다.

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