CT of the small bowel and mesentery

The detection and definition of small bowel pathology is a frequent clinical and radiologic problem. Although contrast radiography and enteroclysis are the primary means of evaluating the small bowel, computed tomography (CT) has become increasingly important as a complementary examination. Initial diagnoses proffered by barium studies may be further characterized by CT and this additional information may have significant impact on patient management.     

儿童肠及肠系膜钝性创伤的CT诊断

目的：探讨CT检查对儿童急性肠及肠系膜钝性创伤的诊断价值。方法：分析11例经临床诊断或手术证实的儿童肠及肠系膜钝性创伤CT表现，全部病例均有明确的腹部外伤史，6例手术治疗，5例保守治疗。结果：11例患者中，胃损伤1例，十二指肠损伤3例，小肠及肠系膜损伤7例。CT表现有气腹、腹腔积液、肠壁肿胀、肠系膜模糊、肠管扩张等。在手术治疗的6例中，胃穿孔1例，小肠穿孔4例．肠壁血肿1例。结论：CT诊断肠及肠系膜急性钝性创伤明显优于X线平片和B超检查。不仅可清晰显示少量腹腔积气，估计腹腔积液、积血的量，显示实质脏器损伤，还可直接显示肠壁、肠系膜血肿，对外科医生确定治疗方案有重要意义。     

Extensive lipomatosis of the small bowel and mesentery: CT and MRI findings

We report a patient with extensive lipomatosis involving both the ileum and mesentery. Axial computed tomographic images showed that diffuse and multiple intramural masses of fat densities compressed the ileum interior and abundant mesenteric fat compressed the retroperitoneum. Coronal magnetic resonance images showed thumbprinting of fluid containing ileum caused by fat-intensity masses.     

Blunt trauma to the gastrointestinal tract: CT findings with small bowel and colon injuries

The CT diagnosis of bowel injury is difficult and warrants an organized approach. Careful scrutiny of CT images for extraluminal gas or fluid and bowel wall thickening is required. Review of images of the entire abdomen and pelvis using lung window settings is recommended, followed by the analysis using soft tissue window settings. Specific search for extraluminal fluid collections with a triangular or matted appearance will help detect bowel injury. Electronic Publication     

Normal enhancement of the small bowel: evaluation with spiral CT

PURPOSE: The purpose of this work was to determine normal contrast enhancement of the small bowel with biphasic spiral CT, using water as oral contrast agent. METHOD: Biphasic spiral CT was performed in 50 healthy patients undergoing evaluation as potential renal donors. All patients received 500 ml of water as oral contrast agent and 150 ml of Omnipaque 350 administered by mechanical injector at a rate of 3 ml/s. Dual phase CT of the abdomen was performed in each patient. Acquisition of early phase images began 30 s after the start of the intravenous injection, and portal phase images were obtained 60 s after initiation of the contrast agent injection. Attenuation measurements (in Hounsfield units) were obtained from the wall of the small bowel (duodenum, jejunum, ileum) in both the arterial and the portal phases. RESULTS: During the arterial phase, the mean (95% confidence interval) attenuation of the duodenum, jejunum, and ileum was 120 (+/- 5), 119 (+/- 5), and 118 (+/- 5) HU, respectively. During the portal phase, the average attenuation of the duodenum, jejunum, and ileum was 111 (+/- 4), 111 (+/- 3), and 107 (+/- 3) HU, respectively. There was no statistically significant difference between the attenuation of the duodenum, jejunum, or ileum within either the arterial or the portal venous phases. There was a statistically significant difference in small bowel enhancement between the arterial and portal venous phases. CONCLUSION: There is no important variation in small bowel attenuation during the 30 and 60 s scanning phases. This study serves as a normal reference that may be helpful when spiral CT is used to evaluate ischemic bowel or inflammatory small bowel diseases.     

Gallstone ileus presenting as small bowel obstruction: spiral CT evaluation

Gallstone ileus is the result of a sequence of events that are initiated in the gallbladder. Inflammation of the gallbladder wall allows erosion of a gallstone through the wall into the small bowel and subsequent bowel obstruction. We present a unique case in which CT scans done over a period of 1 year demonstrate this progression in a patient and alter the clinical management by identifying the correct cause of small bowel obstruction. The clinical presentation, radiologic findings, and management of gallstone ileus are reviewed.     

Primary extraskeletal osteosarcoma of small bowel mesentery presenting with acute bowel obstruction

Extraskeletal osteosarcoma of the small bowel mesentery is an exceedingly rare condition. It is an aggressive malignant neoplasm of mesenchymal origin characterized by osteoid formation. Final diagnosis is often made by histopathological analysis. However, we believe that prospective radiological diagnosis may be possible through careful analysis of densities (ossification) within the mesenteric mass. To the best of our knowledge, there is no current literature describing the radiological approach to making a prospective diagnosis of this condition. We present the 12th case of extraskeletal osteosarcoma worldwide and describe a radiological approach that is potentially useful in making a prospective diagnosis.     

多层螺旋CT在小肠Crohn病中的应用研究

目的 探讨MSCT双期动态增强扫描在小肠Crohn病中的应用价值.方法 45例经综合方法 诊断,并通过临床治疗证实的小肠Crohn病患者均行MSCT双期动态增强扫描,并在ADW4.2工作站进行后处理.测量患病肠段在不同期相内的CT值,采用方差分析比较其CT值;并测量各期相内患病肠段与正常肠段的CT值筹值,以差别10 HU为界,划分病例数,将不同期相内的病例数采用卡方检验进行比较.结果病变肠段平扫平均CT值为(39.3±3.7)HU,动脉期为(74.8±13.8)HU,门静脉期为(90.2±12.3)HU,差异有统计学意义(F=258.87,P<0.01).病变肠段平扫与动脉期和门静脉期CT值两两比较,差异均有统计学意义(P<0.05).45例中,平扫CT值差值≤10 HU和>10 HU者分别为44和1例,动脉期分别为6和39例,门静脉期分别为2和43例,经X2检验,平扫与动脉期间差异有统计学意义(X2=32.49,P<0.01),平扫与门静脉期间差异有统计学意义(X2=39.22,P<0.01),动脉期与门静脉期间差异无统计学意义(X2=1.10,P>0.05).增强扫描使病灶显示更为清楚,大大提高了小肠Crohn病的检出率.结论 MSCT双期动态增强扫描可对小肠Crohn病作出初步诊断,并可对病变进行全面评价.     

Normal anatomy and pathologic changes of the small bowel mesentery: US appearance

The ultrasonographic (US) appearance of the normal small bowel mesenteric leaves was evaluated in two in vitro studies and in 30 patients. Such structures had an elongated shape, echogenic surfaces, and small vessels in their center and could be recognized in 28 of the 30 patients. They did not show active movements, and at their distal end, the small bowel loops could be seen and peristalsis detected. Doppler signals were obtained from the small vascular structures in their center in three additional cases. On the basis of these anatomic findings, pathologic changes such as lymphoma, desmoid tumor, metastatic lesions, dilated vessels, and edema could be detected in 15 patients. When examining with US patients with diseases prone to involve the mesentery, careful attention should be given to this structure, since useful information about the abdominal spread of the disease can be obtained.     

Blunt upper abdominal trauma: evaluation by CT.

CT is the technique of choice for initial examination of hemodynamically stable patients after blunt abdominal trauma. It is highly sensitive, specific, and accurate for use in detecting the presence or absence of injury and defining its extent. Nonoperative management of many posttraumatic injuries, particularly in the liver, spleen, and kidney, is possible in part because of the diagnostic usefulness of CT. CT can be used effectively to visualize the progression of liver and spleen injuries in those patients chosen for conservative management. CT helps in treatment decisions in patients with renal injury by defining the character and extent and distinguishing minor from severe renal trauma. Posttraumatic injuries to the pancrease, bowel, and mesentery can be detected with CT. In these areas, however, signs may be subtle, and a significant injury may be missed on an initial examination.     

肠及肠系膜损伤CT表现对判断手术治疗的指导价值

目的 探讨根据肠及肠系膜损伤CT表现判断是否需要手术治疗的指导价值.方法 回顾性分析48例肠及肠系膜损伤患者的临床资料及CT表现,26例手术治疗,保守治疗22例.2名放射科医师根据CT表现判断是否需要手术治疗,以患者的最终诊断和治疗结果为标准,使用SPSS13.0进行ROC曲线分析.阅片者间差异性评价采用Kappa一致性检验.结果 肠管连续性中断和肠系膜血管内造影剂外溢只见于手术组,腹腔游离气体多见于手术组.2位医师根据CT图像判断是否需要手术治疗,ROC曲线分析准确性较高(曲线下面积Az值均＞0.9).2位医师之间一致性分析结果为中、高度一致.结论 根据CT征象可较准确地判断肠及肠系膜损伤的手术指征.     

Multidetector CT of the small bowel: evaluation after oral hyperhydration with isotonic solution

PURPOSE: The aim of our study was to assess the diagnostic capabilities of multidetector CT in the evaluation of the small bowel in different pathological conditions, with the use of oral hyperhydration with isotonic solution. MATERIALS AND METHODS: The study retrospectively evaluated 106 patients who underwent multidetector CT of the small bowel. Four groups were considered on the basis of the clinical findings: group A (48 cases), with suspected or certain chronic inflammatory disease of the small bowel; group B (16 cases), with suspected neoplastic lesion of the small bowel; group C (17 cases), patients affected by malabsorption; group D (25 cases), others: 13 cases with non-specific abdominal pain, 4 cases with occult bleeding, 8 cases affected by fever of unknown origin. Thirteen patients had previously undergone surgical intestinal resection. In all cases the CT examination was performed after the oral administration of 2000 mL polyethylene glycol electrolyte balanced solution; before the scan, N-butyl scopolamine or glucagon were administered intravenously to obtain rapid inhibition of bowel peristalsis. All multidetector CT scans were acquired at baseline and 50 seconds after the I.V. administration of 110-130 ml high-concentration non-ionic iodinated contrast medium. The images were subsequently processed on a dedicated workstation (Advantage Windows 4.0, GE Medical Systems) to obtain multiplanar reconstruction (MPR). We considered the following CT findings: fold distribution, wall thickening and stratification and contrast enhancement, extraparietal involvement and abnormalities of the abdominal organs. The CT diagnoses were compared with the clinical and laboratory findings (86 cases) and with the results of barium follow-through (55 cases), ileo-colonoscopy (45 cases) or surgery (28 cases). RESULTS: CT examination allowed the correct diagnosis in 86/106 cases (89%); 20 patients were not included in the study because of a poor (11 cases) or absent (9 cases) small bowel loop distension. The final diagnoses in the 86 patients were: Crohn's disease of the small bowel (38 cases), Crohn's disease of the duodenum (1 case), granulomatous colitis (3 cases), malabsorption (8 cases), neoplastic lesion (4 cases), post-radiation conglomeration of ileal loops (1 case), intestinal lymphangiectasia (1 case), ulceration of the last ileal loop (1 case). In 29 cases no abnormalities of the small bowel were found. Spiral CT yielded 52 true positive cases, 5 false negative cases, 2 false positive cases, and 27 true negative RESULTS: The sensitivity of the technique was 91%, specificity 93% and diagnostic accuracy 92%. CONCLUSIONS: Multidetector CT of the small bowel performed after oral hyperhydration with isosmotic solution, proved to be an accurate and thorough technique. It can be considered a safe and effective alternative to conventional radiographic studies and to small bowel spiral CT enema in patients that refuse the nasojejunal balloon catheter or the administration of methylcellulose.     

Metastatic seeding along the small bowel mesentery. Roentgen features.

1. Intra-abdominal malignant seeding along the small bowel mesentery is roentgenologically identifiable. 2. The anatomic features of the small bowel mesentery and the pathways of flow of ascitic fluid along its peritoneal recesses determine the depostion and growth of seeded metastases. 3. Seeded deposits lodge particularly within the lower recesses of the small bowel mesentery and are reflected by typical changes involving distal ileal loops or the cecum. 4. These are characterized by (a) palisading, arcuate scalloped deflections or gross mass displacement of distal small bowel loops in the right lower quadrant, or (b) extrinsic indentations upon the medial and inferior contours of the cecum. Associated desmoplastic reaction may result in tethering of mucosal folds and angulated fixation of bowel loops.     

CT findings of small bowel trichobezoar

A 14-year-old girl presented to our emergency room with abdominal pain and persistent vomiting. A plain radiograph of the abdomen showed features of small bowel obstruction, with dilated loops of small bowel and a mottled gas and debris pattern in the stomach and right lower quadrant. A CT scan of the abdomen and pelvis obtained to exclude appendicitis showed the distinctive appearance of a trichobezoar. A preoperative diagnosis of gastric and intestinal trichobezoar was made. Electronic Publication     

Enteroclysis and spiral CT examination in diagnosis and evaluation of small bowel Crohn's disease

INTRODUCTION: During the last few decades introducing many of new radiologic methods, diagnostic conditions and facilities of Crohn's disease has became markedly improved. Appropriate using of these technics definitely modifies the management of patients with known or suspected Crohn's disease serving reliable information about extent, severity and possible complications of disease. Enteroclysis and Computed tomography are the two major and basic methods to disclose or confirme diagnosis of Crohn's disease, obtain appropriate inforination about disease either with mucosal, transmural or extraintestinal manifestation. METHODS AND PATIENTS: We evaluated 281 patients who were referred in our institution under suspition of Crohn's disease. Enteroclysis and abdominal spiral CT in all cases were carried out usually within 1 week. The 172 patients underwent abdominal spiral CT as the primary examination to evaluate diagnostic value of spiral CT in this entity, while 109 patiens had enteroclysis followed by abdominal CT. In 11 cases we also perforined CT enteroclysis with administration of 0.5% methylcellulose solution thorough nasojejunal tube controlled by electric motor driven contrast pump. Results were compared with final clinical, pathological or surgical data were available. RESULTS: From the 281 patients eventually 74 proved Crohn's disease; sensitivity and specificity of enteroclysis proved to be 96 and 98%, while spiral CT sensitivity and specificity was 94 and 95%, respectively. Enteroclysis was superior to the spiral CT in demonstration of early lesions and functional disorders, while spiral CT proved to be essential in evaluation of transmural and extraintestinal complications. CONCLUSIONS: Regarding enteroclysis and spiral CT as complementary methods, they provide excellent results in diagnosis of Crohn's disease.     

Strangulation of small bowel due to Meckel diverticulum: CT findings.

We report an unusual case of small bowel strangulation due to long Meckel diverticulum. CT demonstration of the bundle-like segment contiguous with the distended fluid-filled loops of bowel contributed to the prompt preoperative diagnosis.