CT and MRI of experimentally induced mesenteric ischemia in a porcine model

OBJECTIVE: Our goal was to assess the value of CT and MRI for the detection of bowel wall changes in experimentally induced mesenteric ischemia. METHODS: in 18 female pigs, a percutaneous embolization of the superior mesenteric artery was performed with buthyl-2-cyanoacrylate and Lipiodol (1:1) (experimental group). In six animals, only diagnostic imaging and histologic evaluation were performed (control group). CT was carried out 3, 6, and 12 h after occlusion. Incremental CT (1 s scan time, 5 mm slice thickness, 7 mm increment, 120 kV/290 mAs) and spiral CT (slice thickness 5 mm, pitch 1.5, 120 kV/165 mA) were performed pre and post contrast injection (Somatom Plus/Siemens). Serial CT was carried out after intravenous contrast injection (1 ml/kg, 2 ml/s). MRI (Magnetom 1.5 T; Siemens) was performed with T1 (pre and post 0.01 mmol/kg Gd-DTPA; Magnevist; Schering, Germany), T2, and proton density images in axial orientation. Slice thickness was 3 mm and slice gap 1 mm. Additionally, a T1-weighted GE sequence (multislice FLASH 2D) was obtained in dynamic technique (before and 30, 60, and 90 s after contrast agent injection) with a slice thickness of 5 mm. Biometrical monitoring included blood pressure, heart frequency, blood cell count, electrolyte status, blood gas analysis, and determination of serum lactate. Image evaluation included morphological analysis and determination of the enhancement pattern. Histological specimens were obtained and analyzed according to the Chiu classification. RESULTS: The histologic workup of the specimen 3, 6, and 12 h after vascular occlusion revealed an average Chiu state 3, 4, and 5. On CT, the bowel wall had a thickness of 4.7 mm on average in the ischemic segments. There was a significant difference from the control group (average 3 mm). Free intraperitoneal fluid and intramural gas were seen after 12 h of ischemia in 80%. In ischemic bowel segments, no mural enhancement was seen. Normal segments and the bowel of the control animals showed an enhancement of 34 HU on average (SD = 3.1 HU; p.<0.01). In MRI, S/N and C/N differed significantly between experimental and control groups in T1 and proton density images. In ischemic segments of all phases, the bowel wall did not show contrast enhancement. Healthy segments and bowel of control animals showed a significant enhancement (p<0.01). CONCLUSION: Cross-sectional imaging has a high sensitivity for delineation of ischemic bowel wall segments. The enhancement pattern of the bowel wall enables detection of location, extent, and cause of a acute arterial mesenteric ischemia with high accuracy in an early phase.     

Differential effects of sunscreens on UVB-induced immunomodulation in humans

Ischemic bowel disease is a rare disorder whose incidence is increasing as the mean age of the population increases. Diagnosis by clinical, laboratory and radiologic means is often difficult, and delay in definitive therapy results in substantial morbidity and mortality. A series of 26 consecutive patients, with proved acute superior mesenteric ischemia, was retrospectively reviewed: the authors report the diagnostic methods performed preoperatively, the site and the cause of infarction and the time passed between the first radiograph ans surgery. Plain abdominal radiographs were performed in 25 of 26 patients, screening abdominal US in 23 cases and CT in 19 cases. All radiological examinations were retrospectively reviewed by three authors, independently, to recognize the different signs of infarction. On plain abdominal films, the findings warranting a presumptive diagnosis of bowel infarction were air-fluid levels (84% of cases), dilated bowel loops (48%), thickened and unchanging loops (20%), gastric distension and gasless abdomen (12%), small bowel pseudo-obstruction (8%). Screening abdominal US demonstrated intraperitoneal free fluid (26%) and dilated bowel loops (22%). Abdominal CT showed air-fluid levels (79%), dilated loops and free intraperitoneal fluid (47%), intramural gas and thickened bowel loops (36.8%), engorgement of the mesenteric vessels (31%), mesenteric-portal gas, mesenteric thrombus and marked reduction in the volume of gas in the small bowel (10.5%) and paper-thin bowel loops (5%). The authors conclude that air-fluid levels, dilated loops and intraperitoneal free fluid are the most frequent findings, even though they are not specific. While abdominal plain film and screening ultrasonography can be negative, CT detects at least one abnormal finding and at least three abnormal findings in 73% of cases.     

Acute graft-versus-host disease in children: abdominal CT findings

PURPOSE: To review the computed tomographic (CT) appearance of acute gastrointestinal graft-versus-host disease (GVHD) in children. MATERIALS AND METHODS: Sixteen abdominal CT scans obtained in 12 children with acute gastrointestinal GVHD who underwent allogeneic bone marrow transplantation (BMT) were compared with 16 CT scans obtained in autologous bone marrow recipients not at risk for GVHD (control group). Autopsy findings in six patients with GVHD were compared with CT findings. RESULTS: All CT scans in patients with GVHD showed an abnormally enhanced, thin mucosal layer of bowel wall involving fluid-filled, dilated, poorly opacified bowel loops from the duodenum to the rectum. This corresponded histologically to mucosal destruction and replacement by a thin layer of highly vascular granulation tissue. Bowel wall thickening was often absent. Infiltration of mesenteric fat was seen in 91% of patients The control group showed no similar abnormalities. CONCLUSION: Acute gastrointestinal GVHD characteristically appears on CT scans as multiple, diffuse, fluid-filled bowel loops with a thin, enhancing layer of bowel wall mucosa. Bowel wall thickening often is absent.     

Angiographic image of intestinal angiodysplasia of the duodenum in comparison with endoscopy--case report

Angiodysplasia of the bowel wall is a malformation of intestinal giodysplasia of the bowel wall is a malformation of intestinal blood vessels. There seem to be different aetiologies of this disease entity. It is reported to be a common cause of occult intestinal bleeding in patients with negative findings on primary endoscopy of the upper and lower gastrointestinal tract. They occur most frequently in the right colon. The case reported demonstrates endoscopy and arteriography of extensive angiodysplasia in duodenum and proximal jejunum causing severe bleeding.     

Antistaphylococcal and antistreptococcal killing kinetics of ciprofloxacin, ofloxacin, sparfloxacin, and trovafloxacin

BACKGROUND: Use of blood culture studies for early diagnosis of Mycobacterium avium complex (MAC) infection has become important due to the recent development of effective antibiotic therapy for this condition. This study assessed the abdominal computed tomography (CT) findings in patients with AIDS who presented with bacteraemic MAC infection. METHODS: A retrospective analysis of abdominal CT scans was performed in 24 patients who presented with MAC-positive blood culture. CT images were reviewed specifically to evaluate for lymph node enlargement and attenuation, hepatomegaly, splenomegaly, bowel wall abnormality and for any other pathological changes. Comparison was made to prior reports of the CT findings in this disease process. RESULT: Enlarged intra-abdominal mesenteric and/or retroperitoneal lymph nodes were found in 10 patients (42%). These nodes were characterized by homogeneous, soft-tissue attenuation in eight of the 10 patients. Hepatomegaly, splenomegaly and small bowel wall thickening were noted in 12 (50%), 11 (46%) and four (14%) patients, respectively. CT findings were evaluated as normal in six (25%) patients. CONCLUSIONS: Enlarged mesenteric and/or retroperitoneal lymph nodes in AIDS patients with bacteraemic MAC were observed much less frequently on CT than previously reported in AIDS patient populations. Normal abdominal CT findings do not exclude this diagnosis and may reflect a trend towards earlier detection of MAC disease.     

Bilateral hypothalamic dopamine infusion in male Zucker rat suppresses feeding due to reduced meal size

PURPOSE: To determine whether vascular, ischemic, and inflammatory causes of bowel wall thickening in children can be differentiated at gray-scale and color Doppler ultrasonography (US). MATERIALS AND METHODS: Thirty-seven children with acute bowel disease underwent graded compression US. Findings of bowel wall thickness, wall echotexture, location of bowel involvement, and presence of color Doppler flow were evaluated. Diagnoses were classified as inflammation (n = 25), vasculitis (n = 7), or ischemia (n = 5) and were confirmed with findings from colonoscopy and biopsy, stool culture analysis, surgery, and cutaneous biopsy, and with a combination of clinical and laboratory data. RESULTS: Patient age (P = .0022), bowel wall thickness (P = .0001), and color Doppler flow (P = .0013) were statistically significantly related to disease type. Wall thickening and absence of visible color Doppler flow suggested ischemia. Older patient age and visible color Doppler flow suggested inflammation, whereas younger patient age and visible color flow suggested vasculitis. Difference in location of bowel disease in patients with ischemic versus those with vascular wall thickening was statistically significant (P = .0185). No difference was found between disease type and wall stratification. CONCLUSION: Gray-scale and color Doppler flow US can aid in differentiating ischemic, vascular, and inflammatory bowel wall thickening.     

Computed tomography in a case of pseudomembranous colitis

Pseudomembranous colitis (PMC) is an infectious colitis usually occurring as a complication of antibiotic therapy. The computed tomography (CT) findings of 10 patients with PMC are reviewed. All patients demonstrated an abnormal large bowel wall with an average thickness of 13 mm (range 7-31 mm). Additional, but less frequent findings included mesenteric inflammation, ascites, pleural effusions, and dilatation of the large or small bowel. Pancolonic involvement was seen in 7 cases, while three patients had focal colitis. Although the CT appearance of PMC is not specific, the diagnosis may be suggested in the proper clinical setting.     

Antimetabolite-induced apoptosis in Tenon''s capsule fibroblasts

PURPOSE: To analyze the computed tomographic (CT) features of intestinal Beh?et syndrome and to determine the usefulness of CT in detecting complications. MATERIALS AND METHODS: The CT scans of 28 patients with intestinal Beh?et syndrome were retrospectively reviewed. Five patients had bowel perforation, and two had peritonitis. Patterns of bowel involvement, patterns of contrast enhancement, and ancillary findings were compared in patients with complications (n = 7) and patients without complications (n = 21). RESULTS: Ten patients had polypoid lesions, nine had a thickened bowel wall, and nine had both findings. Lesion enhancement was mild in eight patients (29%) and marked in 20 (71%). Polypoid lesions were more commonly seen in patients without complications (P = .020); a thickened bowel wall was more commonly seen in patients with complications (P = .030). Seventeen of 18 patients (94%) with minimal perienteric infiltration did not have complications (P = .0003), whereas all five patients with severe perienteric infiltration did have complications. CONCLUSION: In patients with known intestinal Beh?et syndrome, CT can be useful in determining the extent of the lesions and in identifying cases in which complications are likely to occur.     

CT of appendicitis in children

PURPOSE: Our goal was to review the CT findings and to help define the role of CT in the evaluation of appendicitis in children. METHOD: Of 730 children with surgically proven appendicitis, 22 underwent preoperative CT evaluation. Their CT scans and operative and pathology records were retrospectively reviewed. The CT scans were evaluated for appendiceal wall thickness, diameter, and location, appendicoliths, pericecal inflammation, phlegmon, abscess, free fluid, small bowel dilatation, and bowel wall thickening. Criteria for diagnosing appendicitis were (a) appendiceal wall thickening (> 1 mm) or (b) presence of abscess, phlegmon, or pericecal inflammation associated with appendicolith(s). Prospective reports of ultrasound examinations performed within 2 days of the CT scans were available in 14 children and were correlated with the CT findings. RESULTS: An abnormally thickened appendix, with a diameter ranging from 9 to 18 mm, was seen in four children. Three appendices were retrocecal and one was near the cecal tip, anterior to the iliac vessels. Appendicoliths were present in 10 children, multiple in 1. Abscesses were seen in 13 of 22 children, multiple in 5. Phlegmon was seen in five children and pericecal inflammation in two. Bowel wall thickening was present in seven children and small bowel dilatation was noted in six. Other findings included free fluid, hydronephrosis, thickening of urinary bladder wall, air in the uterus and vagina, adenopathy, and thickening of the abdominal wall musculature. CT was diagnostic of appendicitis in 11 of 22 children (50%). In 14 children with both ultrasound and CT studies, CT was slightly better in diagnosing appendicitis and visualizing the abnormal appendix and was superior in defining the presence and extent of abscess and inflammation in 9 of 14 children. CONCLUSION: CT is a useful adjunct in diagnosing appendicitis in children, with a major role in cases of complicated appendicitis.     

Ileal penetration by a Multiload-Cu 375 intrauterine contraceptive device. A case report with review of the literature

A case of a 28-year-old gravida 3 para 2 woman with an ileal penetration by an intrauterine device (IUD) is reported. Four weeks following insertion of a Multiload-Cu 375, the woman underwent laparotomy due to persistent vague abdominal pain and translocation of the IUD. The device had perforated the fundal uterine wall and the two flexible side arms and the copper-bearing rod had completely eroded into the wall of the ileum with only the strings protruding outside the small bowel mesentery. Resection of an ileal segment with end-to-end anastomosis was performed. The woman made an uneventful recovery. It appears that a translocated Multiload-Cu 375 IUD body can penetrate and be entirely embedded within the bowel wall as early as 4 weeks following translocation. This report documents the shortest interval between insertion and proven bowel injury by an IUD.     

Drug-induced linear IgA disease: target antigens are heterogeneous

BACKGROUND: Colonic strictures represent an advanced stage of fibrosing colonopathy in patients with cystic fibrosis. AIMS: To clarify whether ultrasonography can identify patients with an early stage of fibrosing colonopathy and to determine clinical factors that influence bowel wall thickening. PATIENTS: Ninety patients with cystic fibrosis, median age 10 years, and 46 healthy controls, median age 13 years, were investigated. METHODS: Bowel wall thickness was measured by ultrasound in a prospective study. RESULTS: In cystic fibrosis, wall thickness of both small intestine and colon was significantly (p < 0.0001) higher than in controls; 81% of patients with cystic fibrosis had a maximum colon wall thickness at any site of 2 mm or more, a value that was never reached by controls. The maximum colon wall thickness was 6.5 mm. Bowel wall thickness was unchanged at re-examination after one year. There was no progression even with high dose pancreatic supplements. There was no association between bowel wall thickness and clinical features such as previous meconium ileus, intestinal resection, distal intestinal obstruction syndrome, abdominal pain, or pancreatic enzyme dose. CONCLUSIONS: There is genuine intestinal involvement in cystic fibrosis; in a few cases this could lead to fibrosing colonopathy.     

Bacterial infections among home delivered neonates. Clinical picture and bacteriological profile

Thirteen cases of emergency left colon resection with primary anastomosis are presented. Production of an empty bowel and use of parenteral hyperalimentation, to delay intake until healing is evidenced by bowel function, are absolutely necessary, The "elective environment," assuring primary healing of the left colon anastomosis, consists of several factors: an empty decompressed bowel with adequate lumen, an antibiotic-depressed colon bacterial flora, assured blood supply, healthy bowel wall, and absence of anastomotic tension. The importance of not extraperitonealizing the anastomosis and the danger of long-term drains are emphasized.     

Reliability of color Doppler and power Doppler sonography in the evaluation of intussuscepted bowel viability

In two similar cases of irreducible intussusception with wall necrosis and perforation, symptoms had begun 24 h before admission and the plain radiographs showed signs of small-bowel obstruction. The sonographic (US) appearances, however, were different: color Doppler (CD) US showed vascular flow in the intussuscepted bowel in one case and no flow in the other. After radio-clinical assessment, both children underwent surgery and an intestinal resection had to be performed, manual reduction being impossible. The reliability of the US findings and the prognostic value of CD and power Doppler US in determining the viability of the intussuscepted bowel are discussed with a review of the literature.     

Myoelectric activity during small bowel allograft rejection

The effect of rejection on myoelectric activity of an orthotopically transplanted small intestinal segment (group I, N = 14) was studied. Electrodes were placed on grafts and recipient small bowel. Isografts (group II, N = 5) and native bowel (group III, N = 5) served as controls. The first morphological signs of rejection were seen on day 6 and steadily progressed until day 11, when the cellular infiltrate involved all layers of the bowel wall. Slow-wave frequencies remained unchanged throughout the observation period. No difference was detectable between grafts (group I: 31.9 +/- 1.65; group II: 31.36 +/- 0.7) and native bowel after transection (group I: 32.16 +/- 1.78; group II: 31.50 +/- 1.01), which was different (P = 0.0001) from intact bowel of group III animals (38.4 +/- 0.81). Irregular MMCs were detectable in grafts from day 5 on and replaced after food intake by random spiking activities. At day 8, spiking activities disappeared in allografts, which showed a still preserved mucosal architecture, while slow-wave activities continued. These findings demonstrate that intestinal allografts during rejection develop paralysis before mucosal destruction is established, which might be of clinical relevance.     

Embodied Energy and Gas Emissions of Retaining Wall Structures

The embodied energy (EE) and gas emissions of four design alternatives for an embankment retaining wall system are analyzed for a hypothetical highway construction project. The airborne emissions considered are carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), sulphur oxides (SOX), and nitrogen oxides (NOX). The process stages considered in this study are the initial materials production, transportation of construction machineries and materials, machinery operation during installation, and machinery depreciations. The objectives are (1)?to determine whether there are statistically significant differences among the structural alternatives; (2)?to understand the relative proportions of impacts for the process stages within each design; (3)?to contextualize the impacts to other aspects in life by comparing the computed EE values to household energy consumption and car emission values; and (4)?to examine the validity of the adopted EE as an environmental impact indicator through comparison with the amount of gas emissions. For the project considered in this study, the calculated results indicate that propped steel sheet pile wall and minipile wall systems have less embodied energy and gas emissions than cantilever steel tubular wall and secant concrete pile wall systems. The difference in CO2 emission for the retaining wall of 100?m length between the most and least environmentally preferable wall design is equivalent to an average 2.0?L family car being driven for 6.2?million miles (or 62 cars with a mileage of 10,000??miles/year for 10?years). The impacts in construction are generally notable and careful consideration and optimization of designs will reduce such impacts. The use of recycled steel or steel pile as reinforcement bar is effective in reducing the environmental impact. The embodied energy value of a given design is correlated to the amount of gas emissions.     

Small bowel obstruction due to phytobezoar: CT diagnosis

We report two cases of small bowel obstruction (SBO) due to phytobezoar impaction. In both cases, computed tomography (CT) demonstrated a well-defined, ovoid intraluminal mass with mottled gas pattern within the dilated small bowel at the site of obstruction and an abruptly collapsed lumen beyond the lesion. Recognition of these CT findings allows specific preoperative diagnosis of SBO owing to this uncommon lesion.     

Usefulness of Doppler ultrasound in the evaluation of patients with active Crohn's disease

OBJECTIVES: To assess the usefulness of Doppler ultrasound in the evaluation of the vascular changes in the splanchnic circulation and bowel wall described in patients with active Crohn's disease (ACD). DESIGN: We analyzed prospectively with Doppler ultrasound the mean velocity of portal flow, the resistive index (RI) of the superior mesentery artery (SMA) and we looked for vessels within the bowel wall. PATIENTS: 50 patients with ACD and 30 normal individuals. RESULTS: In comparison with normal individuals, patients with ACD showed a statistically significant difference (p < 0.001) in the mean velocity of the portal flow and in the RI of the SMA. In all patients with ACD, vessels could be seen within the bowel wall using the color Doppler ultrasound. CONCLUSION: Doppler ultrasound can be used as a non-invasive method to evaluate the vascular changes which develop in the splanchnic circulation and bowel wall of patients with ACD.     

Colorectal hydrosonography in diagnosis of tumorous and inflammatory diseases of the large intestine

PURPOSE: Evaluation as to whether diagnosis of large bowel disease and TNM staging of colorectal carcinoma are possible by colorectal hydrosonography (HUS). METHOD: 52 patients with suspected neoplastic or inflammatory large bowel disease, underwent HUS. Before performing abdominal ultrasound, the colon was filled with fluid. Morphological alterations of the bowel wall were judged benign or malignant. Colorectal carcinomas were classified according to the TNM system. RESULTS: Laparotomy was performed in 46 of 52 patients. Correlation with surgery and histopathology showed that 77% of morphologic alterations of the colonic wall were detected by HUS. While benign lesions of the colonic wall occasionally mimicked malignant disease, colonic carcinomas were reliably diagnosed by HUS, because destruction and invasion of the bowel wall was visible. Carcinomas of the lower part of the rectum, however, were missed in most cases. Accuracy to determine the infiltration depth of colorectal carcinomas was 89%, but hydrosonographic N-staging was unreliable. Inflammatory disease of the large bowel as well as changes complicating the inflammatory bowel disease were accurately diagnosed by HUS. CONCLUSION: In selected patients, colorectal HUS is suited for diagnosis and staging of colonic tumours. It also helps to evaluate inflammatory bowel disease, because small and large bowel can be reliably distinguished from each other and the degree of stenosis of inflamed colonic segments becomes visible. Furthermore, HUS increases the visibility of fistulas.     

Unexplained refractory iron-deficiency anemia associated with Helicobacter pylori gastric infection in children: further clinical evidence

A case report of lethal distant myonecrosis with gas gangrene is presented. Cultures from blood and suppuration of our patient revealed Clostridium septicum. At obduction the patient appeared to have a necrotic metastasis of a known ovarian carcinoma in the cecum wall. Predisposing conditions for this type of infection are hematologic malignancies, colon carcinoma, neutropenia, diabetes mellitus, and disruption of the bowel mucosa. Clostridium septicum is highly associated with the presence of a malignancy, either known or occult at the time infection occurs. Occult tumors are mostly situated in the cecal area of the bowel. Clinical symptoms of the syndrome and therapeutic options are discussed.     

Usefulness of CT in patients with intestinal obstruction who have undergone abdominal surgery for malignancy

OBJECTIVE: The purpose of this study was to evaluate the usefulness of CT in determining the causes of intestinal obstruction in patients who have undergone abdominal surgery for malignancy. MATERIALS AND METHODS: We analyzed the CT scans of 55 patients with benign (n = 26) or malignant (n = 29) intestinal obstruction that developed after abdominal surgery for malignancy. After calculating the diagnostic accuracy of interpretations by three radiologists, we compared CT findings for benign and malignant intestinal obstructions with respect to peritoneal involvement patterns and other ancillary findings. Multivariate logistic regression analysis was used to determine the diagnostic performance of CT in revealing causes of obstruction. RESULTS: Diagnostic accuracies of the three radiologists were 67%, 75%, and 78%. CT findings indicating malignant obstruction were a mass at the site of obstruction or prior surgery, lymphadenopathy, or an abrupt transition zone and irregular bowel wall thickening at obstructed sites (p < .05). Conversely, the chance for benign obstruction increased when CT revealed mesenteric vascular changes, a large amount of ascites, or a smooth transition zone and smooth bowel wall thickening at the obstructed site (p < .05). With multivariate logistic regression analysis using two variables (a mass at the site of obstruction or prior surgery and lymphadenopathy), we calculated the overall accuracy of CT as 84% (46/55 patients). CONCLUSION: CT is useful in differentiating benign from malignant intestinal obstructions in patients who have undergone abdominal surgery for malignancy. However, CT has limitations in patients not having a demonstrable peritoneal mass.