多层螺旋CT及后处理技术对肠系膜上动脉栓塞的诊断价值

目的：探讨多层螺旋CT（MSCT）及其后处理技术对肠系膜上动脉栓塞（SMAT）的诊断价值。方法：经CTA诊断为肠系膜上动脉栓塞及继发性改变的11例患者,均经DSA或手术证实。所有病例均行螺旋CT增强扫描,并采用多平面重组（MPR）、曲面重组（CPR）、最大密度投影（MIP）、容积再现（VR）等方法进行后处理。对SMAT的CTA表现及肠系膜、肠管等的继发性表现进行观察分析。结果：11例CT增强扫描表现均为肠系膜上动脉增粗和血管腔内充盈缺损。可见肠腔扩张、积气、积液和／或液-气平面7例,肠壁变薄2例,肠壁增厚及强化程度减低或不强化8例;肠系膜水肿5例,肠系膜积液2例;气体集聚2例,分别位于肠壁、肠系膜内及腹腔。结论：MSCT能够对肠系膜上动脉栓塞及继发病变进行快速、及时、准确地诊断,并能判断肠管缺血的程度,与DSA及手术所见相符,是诊断肠系膜血管栓塞性病变的有价值的影像学方法。     

多层螺旋CT在肠系膜缺血诊断中的应用

目的：探讨多层螺旋CT（MSCT）对肠系膜缺血的诊断价值和临床意义。方法：对43例怀疑肠系膜缺血患者行MSCT检查,包括平扫、动脉期和门静脉期扫描,采用容积成像（VR）、多平面重组（MPR）和最大密度投影（MIP）进行动脉和门脉成像,评价并分析异常的MSCT征象。结果：肠系膜上动脉栓塞7例,管腔内血栓影,肠管扩张积气、积液;肠壁无强化,5例肠壁变薄,2例肠壁水肿增厚。肠系膜上静脉血栓形成36例,肠管扩张积气、积液33例;肠壁水肿增厚伴密度改变（面包圈征）25例;肠系膜血管增粗,脂肪渗出（缆绳征）17例;肠系膜血管走行异常（漩涡征）9例;肠系膜静脉管腔内充盈缺损36例,管壁强化（靶征）27例。结论：MSCT扫描与三维重组技术相结合能准确诊断肠系膜缺血并明确其缺血程度、范围,是一种有效的、无创的影像学检查手段。     

双源CT双期增强血管成像对急性肠缺血的诊断

目的:探讨双源CT(DSCT)双期增强扫描血管成像对急性肠缺血(acute mesenteric ischemia,AMI)患者的诊断价值。方法:回顾性分析经手术或介入治疗证实的26例AMI患者的DSCT资料。所有患者均行DSCT双期增强扫描即动脉期和门静脉期血管成像。结果:肠系膜上动脉栓塞8例,肠系膜上动脉血栓形成4例,肠系膜上静脉血栓形成14例。CT直接征象为肠系膜血管内低密度充盈缺损,受累血管腔闭塞(17例)或重度狭窄(9例)。间接征象:肠壁增厚(21例),肠管扩张、肠腔内积液积气(18例),肠壁强化程度降低(7例),肠壁积气(5例),肠系膜脂肪水肿及渗出(19例),"缆绳征"14例,腹腔积液12例。结论:DSCT增强扫描及双期血管成像可清楚显示AMI血管阻塞的部位、范围、程度及继发改变,对明确诊断和指导治疗具有较高的应用价值。     

CT features of systemic lupus erythematosus in patients with acute abdominal pain: emphasis on ischemic bowel disease

PURPOSE: To evaluate the computed tomographic (CT) features of systemic lupus erythematosus (SLE) in patients with acute abdominal pain. Special emphasis was placed on the analysis of ischemic bowel disease. MATERIALS AND METHODS: The authors retrospectively reviewed the images from 39 abdominal CT examinations performed in 33 patients with SLE and acute abdominal pain. Images were evaluated for bowel wall changes, mesenteric changes, fluid collection, retroperitoneal lymphadenopathy, peritoneal enhancement, and hepatomegaly as well as for changes in other abdominal organs. Ischemic bowel disease was diagnosed if at least three of the following signs were seen: bowel wall thickening, target sign, dilatation of intestinal segments, engorgement of mesenteric vessels, and increased attenuation of mesenteric fat. RESULTS: Thirty-one (79%) of the 39 examinations had CT findings diagnostic of ischemic bowel disease, including symmetric bowel wall thickening (n = 29), target sign (n = 26), and mesenteric vascular engorgement and haziness (n = 31). In 24 cases, bowel wall thickening was multifocal, with variable length, and did not appear to be confined to a single vascular territory. CONCLUSION: The most common CT finding in patients with SLE and acute abdominal pain is ischemic bowel disease. CT is useful for detecting the primary cause of gastrointestinal symptoms, planning treatment, and monitoring for infarction or perforation.     

CT and MR imaging findings of bowel ischemia from various primary causes.

Ischemic bowel disease represents a broad spectrum of diseases with various clinical and radiologic manifestations, which range from localized transient ischemia to catastrophic necrosis of the gastrointestinal tract. The primary causes of insufficient blood flow to the intestine are diverse and include thromboembolism, nonocclusive causes, bowel obstruction, neoplasms, vasculitis, abdominal inflammatory conditions, trauma, chemotherapy, radiation, and corrosive injury. Computed tomography (CT) or magnetic resonance (MR) imaging can demonstrate the ischemic bowel segment and may be helpful in determining the primary cause. The CT and MR imaging findings include bowel wall thickening with or without the target sign, intramural pneumatosis, mesenteric or portal venous gas, and mesenteric arterial or venous thromboembolism. Other CT findings include engorgement of mesenteric veins and mesenteric edema, lack of bowel wall enhancement, increased enhancement of the thickened bowel wall, bowel obstruction, and infarction of other abdominal organs. However, regardless of the primary cause, the imaging findings of bowel ischemia are similar. Furthermore, the bowel changes simulate inflammatory or neoplastic conditions. Understanding the pathogenesis of various conditions leading to mesenteric ischemia helps the radiologist recognize ischemic bowel disease and avoid delayed diagnosis, unnecessary surgery, or less than optimal management.     

Helical CT signs in the diagnosis of intestinal ischemia in small-bowel obstruction

OBJECTIVE: The purpose of our study was to determine prospectively the value of helical CT and of various signs of ischemia in the context of acute bowel obstruction. SUBJECTS AND METHODS: All patients seen over a 3-year period with a CT diagnosis of small-bowel obstruction were included. There were 144 examinations in 142 patients. Images were interpreted prospectively with consensus by a fellow and an experienced gastrointestinal radiologist. Attention was focused on the presence of the following signs of strangulation and ischemia: reduced enhancement of the small-bowel wall, mural thickening, mesenteric fluid, congestion of small mesenteric veins, and ascites. A diagnosis of ischemia was made if enhancement of the bowel wall was reduced or if at least two of the other signs were found. Results were correlated with surgical findings in 73 cases and clinical follow-up in 71 cases. RESULTS: A diagnosis of ischemia was made at surgery in 24 patients. CT diagnosis was correct in 23 patients (96% sensitivity). There were nine false-positive diagnoses (93% specificity). The negative predictive value of CT was 99%. Reduced enhancement of the bowel wall had a sensitivity of 48% and specificity of 100%, mural thickening had a sensitivity of 38% and specificity of 78%, mesenteric fluid had a sensitivity of 88% and specificity of 90%, congestion of mesenteric veins had a sensitivity of 58% and specificity of 79%, and ascites had a sensitivity of 75% and specificity of 76%. CONCLUSION: Helical CT is a highly sensitive method to diagnose or rule out intestinal ischemia in the context of acute small-bowel obstruction.     

Intestinal ischemia: comparison of plain radiographic and computed tomographic findings

This article illustrates the radiographic and CT findings in 14 patients with proved intestinal ischemia or infarction. Gaseous bowel distention, thumbprinting and pneumatosis were the most frequent radiographic findings; intestinal distention, thickening of the bowel wall, engorgement of mesenteric vessels, and pneumatosis, the most frequent CT findings. The authors conclude that CT offers major advantages for evaluating patients suspected of having intestinal ischemia or infarction.     

绞窄性肠梗阻的螺旋CT增强扫描征象分析

目的:分析螺旋CT增强扫描图像上绞窄性肠梗阻的征象,提高对绞窄性肠梗阻术前诊断的准确性.方法:64例手术证实的绞窄性肠梗阻病例纳入研究,男43例,女21例,年龄23～72岁,平均42岁.采用单排螺旋CT进行全腹部扫描,对比剂以2～3ml/s速度注射,注射后60s扫描,层厚10mm.参照术中所见,回顾性分析上述CT资料,包括:①间接征象:肠腔扩张积液,肠壁增厚及肠壁密度改变(靶征),肠系膜脂肪水肿及渗出(缆绳征),肠系膜血管增粗并肠系膜扭曲(漩涡征),肠壁间、肠系膜间及门静脉积气,腹水;②直接征象:肠系膜上动脉或上静脉充盈缺损.结果:正确诊断54例,正确率82.8％.CT显示肠腔扩张积液47例(73％),其中6例积液呈高密度提示肠腔内积血(9.3％);肠壁水肿增厚19例(29.6％),其中11例增强后肠壁密度不匀,呈“靶征”(17％),8例肌壁未见强化(12.5％);肠系膜脂肪水肿及渗出(缆绳征)43例(67％),肠系膜血管增粗并肠系膜扭曲呈“漩涡”状9例(14％),肠壁间积气、肠系膜积气各1例,门静脉积气2例,腹水31例(48.4％).肠系膜上动脉或上静脉充盈缺损3例.结论:绞窄性肠梗阻CT表现有一定特征,可做出提示性诊断.     

Acute and chronic mesenteric ischemia: Multidetector CT and CT angiographic findings

Aim of the work

To assess the role of multidetector CT (MDCT) and CT angiography (CTA) in the diagnosis of acute and chronic mesenteric ischemia.

Patients and methods

This prospective study was performed on 57 consecutive patients clinically suspected of having mesenteric ischemia, they were examined with 16-row multidetector CT, MDCT and CTA were evaluated for evidence of bowel wall changes and abnormal mesenteric vascular changes.

Results

Twenty one patients of studied 57 patients had an abnormal CTA finding diagnostic of mesenteric ischemia and they constituted the material of this study, the most prevalent MDCT findings were bowel wall thickening, bowel distension and non-enhanced bowel wall. MDCT and CTA gave an accurate diagnosis of the cause of mesenteric ischemia as proved by the final diagnosis based on surgical exploration, conventional angiography, laboratory investigations and clinical follow up with 100% sensitivity and specificity.

Conclusion

MDCT and CTA are fast, safe, accurate and non-invasive imaging modalities of choice in patients with suspected mesenteric ischemia which are able to evaluate not only mesenteric vascular structures but also evaluate bowel wall changes and adjacent mesentery, thus detecting the primary cause of mesenteric ischemia that can lead to earlier diagnosis and intervention.     

急性肠系膜血管梗塞的CT表现

目的评价CT对急性肠系膜血管梗塞（AMI）的诊断价值。方法搜集AMI病例10例，男6例，女4例，平均年龄67．2岁。除1例在诊断次日死亡外，其余均经手术病理证实。其中肠系膜上动脉（SMA）梗塞4例，肠系膜上静脉梗塞（SMV）5例，肠系膜下静脉（IMV）梗塞1例。除1例行CT平扫外，其余9例均行CT平扫及增强扫描，详细分析其影像学表现。结果直接征象为血管内充盈缺损（8例）。间接征象包括肠腔扩张积液（4例）、肠壁增厚（6例）、薄纸样肠壁（4例）、缆绳征（5例）、肠系膜积液（3例）、肠壁积气（2例）、门静脉积气（1例）及腹腔积液（3例）。结论CT是诊断急性肠系膜血管梗塞的一种快速、敏感、可靠及无创伤的影像学方法。     

Foreign body ingestion of blister pill pack causing small bowel obstruction

We report a case of foreign body ingestion of a blister pill pack, causing small bowel obstruction. A 76-year-old woman on multiple medications presented with 3 days of progressive abdominal distention, nausea, and vomiting. A computed tomography (CT) scan demonstrated small bowel obstruction with a distinctive metallic foreign body in the distal ileum with associated wall thickening and mesenteric inflammatory changes. At exploratory laparotomy, an impacted, intact blister pill pack was removed from the distal ileum. The ingestion of blister pill packs has been associated with a range of clinical and imaging findings. To our knowledge, this is the only reported case of CT diagnosis of small bowel obstruction caused by blister pack ingestion. Early recognition of the imaging findings of an ingested blister pill pack is important to expedite appropriate management.     

Computerized tomography features of intestinal infarction: 56 surgically treated patients of which 5 with reversible mesenteric ischemia]

PURPOSE: Bowel infarction is a rare and typical condition of the elderly; despite improvements in diagnostic imaging and vascular surgery, bowel infarction remains a major cause of acute abdomen, with mortality rates ranging 70-80%. Diagnosis is often late because clinical signs, laboratory data and radiologic findings are aspecific. We investigated radiographic and particularly CT patterns of intestinal infarction in 56 patients submitted to surgery within 12 hours of admission. We also report the CT findings of 5 of these patients who had reversible mesenteric ischemia. MATERIAL AND METHODS: We retrospectively reviewed 56 cases of bowel infarction. The patients were 29 men and 27 women ranging in age 46-84 years (mean: 63). All the patients were submitted to plain radiography of the abdomen in different projections; emergency CT was carried out with i.v. contrast agent injection. We considered the following CT patterns: dilatation of intestinal loops > 2.5-3 mm, wall thickening > 3-4 mm, intraperitoneal effusion, stuffing of mesenteric vessels with diameter > 3 mm, air-fluid levels. RESULTS: Patients in the 7th decade of life were most frequently affected (38 cases), with an overall mortality rate of 59% (33 deaths). Plain radiography showed distention of bowel loops with air-fluid levels in 91% of cases. CT proved to be an accurate technique with higher sensitivity than radiography in detecting mesenteric edema and hemorrhage (68%), abdominal and pelvic effusion (88%), parietal pneumatosis (9%), wall thickening (29%), intraportal gas (7%), and thrombosis of superior mesenteric artery (3.5%). CT patterns in the 5 patients with reversible intestinal ischemia were wall thickening (80%), peritoneal effusion (80%), meteoric dilatatation (40%), a blurred appearance of mesenteric fat (40%). CONCLUSIONS: Angiography is a valuable imaging and treatment technique permitting the diagnosis of vascular occlusion and the intraarterial infusion of vasodilators, but it can be carried out in emergency in few centers only. This makes conventional radiology, and particularly CT, the only tool providing useful information for early diagnosis and treatment of bowel infarction. CT is more sensitive than radiography and does not exhibit the limitations of angiography--i.e., invasiveness, radiation exposure and complex organization. Therefore CT can presently be considered the method of choice in patients with suspected bowel infarction.     

Small-bowel disease: categorization by CT examination

Fifty patients with no small-bowel disease were evaluated by CT to determine the normal appearance of the small bowel and mesentery. Subsequently, the CT findings in 95 patients with proven small-bowel disease were analyzed to determine which CT observations correlated with neoplastic, inflammatory, or edema-producing processes. Thirty-three (83%) of 40 patients with wall thickening or mesenteric masses greater than 1.5 cm had a neoplastic process. Twenty-eight (82%) of 34 patients with normal mesenteric fat attenuation, wall thickening less than 1.5 cm, or mesenteric masses less than 1.5 cm had inflammatory disease. Fourteen (67%) of 21 patients with no mesenteric mass, increased mesenteric fat attenuation, and wall thickening less than 1.5 cm had noninflammatory edema. Overall, CT assigned 75 (79%) of 95 patients into appropriate categories; use of ancillary CT findings led to correct categorization in 83 (87%). CT is helpful in correctly assigning a disease category to patients with small-bowel wall thickening.     

Computed tomography of intramural intestinal hemorrhage and bowel ischemia

The CT findings of eight patients with intramural intestinal hemorrhage are described and illustrated. Two patients had ischemic bowel disease: in the other six cases pertinent clinical histories led to an accurate diagnosis. Computed tomography demonstrated similar findings consisting of circumferential and symmetrical wall thickening homogeneous in density, a slightly narrowed intestinal lumen, and sharp outer contour. The disease had a segmental distribution affecting different parts of the intestinal tract. In six patients edematous and congestive mesenteric changes were seen and in two patients intraperitoneal blood was detected. An adequate history and careful clinical evaluation are crucial in differentiating the more benign forms of intramural hemorrhage from bowel ischemia.     

CT对肠系膜损伤的评价研究

目的 评价腹部CT对肠系膜损伤的诊断价值。方法 回顾14例经手术证实肠系膜损伤患者临床资料和CT检查结果，分析腹膜腔内游离积液、肠系膜脂肪内渗出、肠系膜血肿、造影剂血管外溢和肠壁增厚强化等CT征象，并结合手术结果确定CT表现对诊断肠系膜损伤的敏感性。结果 所有14例患者的CT图像均显示有腹膜腔游离积液或积血和肠系膜脂肪内渗出，其中12例可见肠系膜内血肿，2例显示有肠壁增厚强化，1例可见造影剂血管外溢，且CT表现与手术结果一致。结论 CT对于肠系膜损伤的诊断具有很好的敏感性，其CT表现有助于判断损伤的部位。     

急性门静脉和肠系膜上静脉血栓形成的CT诊断

目的:分析急性门静脉及肠系膜上静脉血栓形成的临床及CT表现。方法:回顾性分析9例经手术及临床综合诊断证实的急性门静脉及肠系膜上静脉血栓形成病例的CT表现,9例均行CT平扫,3例行增强扫描。结果:9例CT平扫均显示门静脉或肠系膜上静脉增粗,7例见腔内高密度影,8例见腹腔积液,5例见小肠管壁增厚、水肿;3例强化扫描示静脉内低密度充盈缺损。结论:CT对诊断急性门静脉及肠系膜上静脉血栓形成具有重要意义;临床上对急性腹痛,不明原因腹水及可疑肠梗阻的病例,应注意观察其门脉系统情况。     

Mycobacterium genavense infection in AIDS: imaging findings in eight patients

This retrospective study included eight HIV-positive patients with a M. genavense infection. Seven of these patients had a CT scan of the abdomen and a US examination, whereas one patient with pulmonary symptoms had conventional chest radiographs and thin-section CT scan of the thorax. Multiple large retroperitoneal and mesenteric lymph nodes were demonstrated in seven patients; low-attenuation centers within enlarged nodes were identified in two patients. On CT scans two cases showed circumferential wall thickening of the proximal small bowel with a deep ulceration in one of these patients. Additional findings included focal lesions in the liver (n = 1), spleen (n = 2), splenomegaly (n = 6), and hepatomegaly (n = 4). The CT scans from the thoracic examination demonstrated multiple diffuse nodular infiltrates in both lungs. M. genavense infection should be considered in the differential diagnosis of AIDS patients with CD4 counts below 100 cells/mm³ presenting with abdominal lymphadenopathy, multinodular or homogeneous hepatosplenic enlargement and circumferential thickening of the small bowel wall. Received: 28 March 2000/Revised: 3 July 2000/Accepted: 6 July 2000     

肠系膜上动脉梗死的CT表现

目的：探讨肠系膜上动脉栓塞的CT表现特点。方法：搜集肠系膜上动脉栓塞病例6例,男4例,女2例,平均年龄63岁,其中5例手术证实,1例DSA证实。6例均行腹部平扫加增强CT扫描。结果：肠系膜上动脉内充盈缺损6例,肠壁增厚4例,肠系膜增厚、血管增粗3例,肠腔扩张、肠壁薄纸样改变2例;腹腔积液2例。结论：多层螺旋CT是诊断肠系膜上动脉栓塞的一种有效且无创伤的影像检查方法,可以明确阻塞动脉的部位及范围,对手术较有指导价值。     

Internal hernia: clinical and imaging findings in 17 patients with emphasis on CT criteria

PURPOSE: To review the clinical and radiologic features of internal hernia and to derive useful radiographic and CT criteria to assist in diagnosis. MATERIALS AND METHODS: Retrospective review of medical records revealed 17 patients with surgically proved internal hernia (three paraduodenal, 14 transmesenteric) who had 15 computed tomographic (CT) scans and three small-bowel follow-through (SBFT) images. RESULTS: CT signs common to all types of internal hernia included evidence of small-bowel obstruction; clustering of small bowel; stretched, displaced, crowded, and engorged mesenteric vessels; and displacement of other bowel segments, especially the transverse colon and fourth portion of the duodenum. Left-sided paraduodenal hernias demonstrated a sac-like mass of small-bowel loops interposed between the stomach and pancreatic tail and a posterior mass effect on the stomach. All three paraduodenal hernias were diagnosed confidently at retrospective review of CT and SBFT findings. Transmesenteric hernias demonstrated clustered small-bowel loops adjacent to the abdominal wall without overlying omental fat and central displacement of colon and were frequently complicated by small-bowel volvulus (five of 14) and bowel ischemia (six of 14). CT demonstrated signs of volvulus in four of six patients with ischemia. CT findings considered definitive or suggestive of internal hernia were demonstrated in 15 patients. CONCLUSION: Internal hernia is an important and underdiagnosed condition. Transmesenteric hernia is most common in our experience and is usually related to prior abdominal surgery, especially with creation of a Roux-en-Y anastomosis. CT may allow confident diagnosis in most patients.     

Gastrointestinal complications in the neutropenic patient: characterization and differentiation with abdominal CT

PURPOSE: To characterize the computed tomographic (CT) findings of gastrointestinal complications in neutropenic patients and to identify CT features that can help differentiate these complications. MATERIALS AND METHODS: Abdominal CT scans obtained during a 6-year period were reviewed retrospectively to identify 76 neutropenic patients with radiologic bowel abnormalities. Scans were analyzed for wall thickening, pneumatosis, wall nodularity, mucosal enhancement, bowel dilatation, ascites, and mesenteric stranding. The location and extent of abnormalities were noted. Independent chart and pathology report reviews were used to determine the patients' final diagnoses: neutropenic enterocolitis (n = 53), Clostridium difficile colitis (n = 14), graft-versus-host disease (n = 7), cytomegaloviral colitis (n = 1), and ischemic bowel (n = 1). Results were assessed with the Student t test for quantitative wall thickness and the chi2 test for the number of patients with each diagnosis who demonstrated each CT finding. RESULTS: Mean bowel wall thickening was greatest in C difficile colitis (12 mm) and least in graft-versus-host disease (5 mm). Pneumatosis was limited to neutropenic enterocolitis (21% [11 of 53 patients]) and bowel ischemia. Wall nodularity was significantly more common (P <.01) in C difficile colitis (36% [five of 14 patients]). In graft-versus-host disease, the rates of mucosal enhancement and bowel dilatation were highest (P <.05) (71% [five of seven patients] and 86% [six of seven patients], respectively). In C difficile colitis, the rates of ascites and mesenteric stranding were highest (57% [eight of 14 patients] and 71% [10 of 14 patients], respectively). Although findings in neutropenic enterocolitis and graft-versus-host disease could involve any bowel segment, C difficile colitis was always limited to the colon. CONCLUSION: Several CT findings can help differentiate specific gastrointestinal complications in neutropenic patients.