Computed tomography and magnetic resonance imaging of the acute abdomen

Spontaneous multiple small bowel perforations due to ischemic enteritis: a case report

INTRODUCTION

Spontaneous multiple small bowel perforation refers to the complete transmural disruption of the intestinal wall and is often associated with conditions such as inflammatory bowel disease, infectious enteritis, drugs or autoimmune diseases, and it affects all age groups. Spontaneous multiple small bowel perforations due to ischemic enteritis is a rare clinical entity.

CASE PRESENTATION

A 75-year-old man was admitted to our hospital with acute abdominal pain, vomiting, low-grade fever, bloody diarrhea, and abdominal distension. He had no history of trauma, comorbidities, or medications. Erect chest X-ray showed air under the diaphragm on the right side. An emergency laparotomy was performed. Intraoperatively, ischemic lesions and multiple perforations were localized to the jejunum and ileum and sent for histopathology which showed features of ischemic enteritis. Finally, the patient's postoperative course was uneventful.

CONCLUSION

While ischemic enteritis is uncommon, multiple small bowel ruptures are a rare but real complication.

Multiple small bowel ruptures due to ischemic enteritis: a case report

A rare case of multiple small bowel ruptures due to ischemic enteritis (ISE) is reported. The patient was admitted to the hospital with acute abdominal pain followed by bloody diarrhoeas. Preoperative colonoscopic findings were similar to those presented in Crohn's disease. Intraoperatively, ischemic lesions and multiple ruptures were localized at the jejunum and the proximal ileum. Histopathological examination of the resected bowel segment established the diagnosis of ISE. Although ISE is not common, concurred multiple ruptures of the small bowel is a rare but actual complication.

Chronic epigastric blood collection after coronary artery bypass grafting: case report

A clinical case of epigastric pain 3 months after coronary artery bypass grafting (CABG) is presented. The CT finding of an abdominal mass with thick wall, internal horizontal by-gravity level and linear contrast enhancement at the border between the two different components was correctly interpreted for a chronic hematoma with separation of the formed blood elements from blood serum; in particular, the linear contrast enhancement was related to an artery-feeding vessel.

Three hundred consecutive emergent celiotomies in general surgery patients: influence of advanced diagnostic imaging techniques and procedures on diagnosis

OBJECTIVES

To assess the utility of advanced tests performed before surgery on patients who needed emergent abdominal operations, and to assess the outcomes of these patients relative to their diagnoses.

SUMMARY BACKGROUND DATA

Patients with a potential abdominal catastrophe may have various presentations, contributing to the difficulty of the decision about whether an operation is indicated. Advanced tests can be valuable, but the use of these adjuncts should be appropriate to the clinical status of the patient so that treatment is not delayed. The role of these tools in the evaluation of the patient who may need an emergent abdominal operation is less well defined.

METHODS

Data were reviewed on adult patients undergoing emergent abdominal operations. Entrance criteria included patients who had an emergent abdominal operation, defined as one performed for presumed gastrointestinal perforation, infarction, or hemorrhage within 6 hours of admission or surgical consultation. Advanced tests were those that were time-consuming or invasive or required scheduling with other departments so that the risk/benefit ratio of these tests could be questioned. A useful test was one that provided information that contributed to a change in the patient's management.

RESULTS

During a 5-year period, 300 consecutive adult patients (158 perforations, 66 hemorrhage, 53 ischemia/infarction, and 23 "other") underwent emergent nontrauma celiotomies. Overall, the death rate was 20%. Advanced preoperative tests were performed in 135 (45%) of the 300 patients, and 40 of these patients had delayed treatments. Preoperative localization of bleeding sites was accomplished in 77% of patients with upper gastrointestinal bleeding and 86% of patients with lower gastrointestinal bleeding.

CONCLUSIONS

Most patients in need of emergent abdominal operations should not undergo advanced tests. The primary role of advanced tests in these patients is in the localization of a bleeding site. With the exception of patients who present with hemorrhage, advanced tests frequently cause a delay in treatment.

Advances in imaging of the acute abdomen

Over the last 10 years, the most significant advancement in imaging of the acute abdomen has been the development of helical CT imaging. Rapid breath-hold imaging and improved intravascular opacification have enabled radiologists to obtain volumetric data that can be viewed in smaller slice increments. Helical data can also be analyzed utilizing multiplanar and three-dimensional techniques. With its proven ability to diagnose a wide variety of conditions, CT remains the diagnostic modality of choice for imaging the surgical abdomen. There have been considerable improvements in image resolution in US with improvements in transducer technology. Ultrasonography often serves as the first study in evaluating the pediatric or female patient with right lower quadrant or pelvic pain. Computed tomography may be necessary if US is not diagnostic. Despite these technical advances, plain film radiography should be the first imaging study for suspected cases of bowel perforation or obstruction. Magnetic resonance imaging continues to evolve, with improvements in hardware and software design that allow for faster imaging, but current levels of availability in the acute setting preclude its wider use. Whereas further imaging is not necessary for patients presenting with classic signs and symptoms of various acute abdominal diseases, the atypical patient often requires careful diagnostic imaging. Close consultation between the radiologist and surgeon leads to studies appropriately tailored to meet the diagnostic challenge at hand.

Radiographic imaging modalities for the patient in the emergency department with abdominal complaints

The emergency physician should be aware of the sensitivity and specificity of any radiologic study being considered. Radiographic examinations should be used to answer specific questions raised by the history and physical examination. The need to obtain a given radiologic evaluation should be based on the potential information it may reveal and the likelihood that this information will alter patient care. This cost-effective approach minimizes unnecessary radiation exposure and has been advocated by many authorities. The emergency physician should resist the "knee jerk" tendency to order radiographs to reassure himself or herself of the safety of the patient at discharge. Documentational and legal concerns are equally invalid reasons, as is the feeling that "it's what we always order for patients with this abdominal complaint." A given study may be indicated if the yield is acceptable and treatment of the patient may be altered by the results.

Radiological investigation in acute diverticulitis

Optimal management of acute sigmoid diverticulitis depends on evaluation of the severity of the inflammatory process, in which radiological investigation is a useful but probably underutilized adjunct to clinical assessment. Plain abdominal radiography shows abnormalities in 30-50 per cent of patients but these tend to be non-specific and more accurate information is obtainable from a contrast enema. Although the quality of images produced by a water-soluble contrast agent is inferior to that with barium, the former is less hazardous in the presence of perforation and provides sufficient information to permit rational management decisions to be made. Ultrasonography and computed tomography (CT) are particularly useful in visualizing abscesses. They may be helpful in following the progression or resolution of suppuration and in guiding percutaneous aspiration when appropriate. Despite early reports to the contrary, CT is no more specific than a contrast enema in the diagnosis of acute diverticulitis. Radionuclide scans have little role in the routine assessment of acute diverticulitis and magnetic resonance imaging has not been adequately evaluated. Water-soluble contrast enema is safe, widely available and probably the most useful early supplementary investigation.

A simple device for respiratory gating for the MRI of laboratory animals

Respiratory motion must be overcome if MRI of the abdomen, even at the lowest resolution, is to be performed satisfactorily. A simple and reliable respiratory gating device, based on the interruption of an infrared (IR) optical beam is described. This device has the advantage that gating is based on the position of the chest as opposed to its velocity, and that it can be used without degrading the radiofrequency isolation of a Faraday cage. Its use in animal MRI is illustrated by high resolution (200 microns) images of in vivo rat liver and kidney.

CT demonstration of the appendix in asymptomatic adults

We prospectively examined 103 consecutive adults (67 women, 36 men; mean age: 58.7 years) referred for abdominal and pelvic computed tomography (CT) in whom there was no history of right lower quadrant symptoms or appendectomy. Contiguous 5-mm CT images through the pericecal region were obtained in each subject, once routine scanning was completed. Three radiologists reviewed all CT images and reached a consensus on appendiceal visualization and the quantity of intraperitoneal fat. Statistical methods were applied to the collected data to seek significant associations between a visualized appendix and the following factors: patient age, sex, intraperitoneal fat grade, and the presence of oral contrast in the cecal lumen. The appendix was definitely visualized in only 45 of the 103 patients (43.7%). Analysis of variance revealed no statistically significant correlation between a CT-demonstrated appendix and the four variables examined. The clinical implications of these findings are discussed.

Aids in the diagnosis of acute appendicitis

Methods used to improve the accuracy of diagnosis of acute appendicitis are reviewed. Laparoscopy, barium enema, ultrasonography and computer assistance have all been shown to improve accuracy, but no one method is of proven superiority. Such diagnostic aids or intensive in-hospital observation must be used to reduce the 15-30 per cent negative laparotomy rate when acute appendicitis is suspected, without increasing the incidence of appendiceal perforation.