Intestinal ischemia versus intramural hemorrhage: CT evaluation

An Update on Acute Mesenteric Ischemia

Acute mesenteric ischemia (AMI) is an uncommon yet highly lethal cause of acute abdomen in the emergency setting. Computed tomography (CT) imaging, in particular a biphasic protocol consisting of angiographic and venous phase scans, is widely used to corroborate non-specific clinical findings when suspicions of AMI are high. Techniques such as low kilovoltage peak scanning, dual energy acquisition, or a combined arterial/enteric phase can improve iodine conspicuity and evaluation of bowel enhancement. Biphasic CT with CT angiography is mandatory to directly assess for the 3 primary etiologies of AMI-arterial, venous, and non-occlusive mesenteric ischemia (NOMI), and the CT angiographic findings may be the first visible in the disease. In addition, numerous non-vascular CT findings have also been reported. Bowel wall thickening, mesenteric stranding, and ascites are common but non-specific findings that correlate poorly with disease severity. Pneumatosis intestinalis and portomesenteric venous gas, while not pathognomonic for ischemia, are highly specific in cases of high clinical suspicion. Bowel wall hypoenhancement is an early and specific sign but requires a protocol optimizing iodine conspicuity to confidently identify. Finally, intraperitoneal free air and solid organ infarcts are also highly specific ancillary findings in AMI. AMI occurs as a complication in 10% of small bowel obstruction (SBO) patients, and understanding imaging findings of ischemia in the context of SBO is necessary to aid in treatment planning and reduce over- and under-diagnosis of strangulation. Familiarity with the imaging features of ischemia by radiologists is vital to establish an early diagnosis before irreversible necrosis occurs.

Intestinal Angioedema: A Mimic of an Acute Abdomen

Visceral angioedema presents with features mimicking an acute abdomen, causing a great challenge in the diagnosis of the disease thus delaying the treatment. A high degree of radiological suspicion and clinical correlation will help in identifying this less-known entity, avoiding unnecessary surgery. CT scanning is the preferred investigation, but concomitant ultrasonography improves the diagnostic efficacy of CT scanning.

Practical Applications of Dual-Energy Computed Tomography in the Acute Abdomen

With new developments in workflow automation, as well as technological advances enabling faster imaging with improved image quality and dose profile, dual-energy computed tomography is being used more often in the imaging of the acutely ill and injured patient. Its ability to identify iodine, differentiate it from hematoma or calcification, and improve contrast resolution has proven invaluable in the assessment of organ perfusion, organ injury, and inflammation.

CT abdominal imaging findings in patients with sickle cell disease: acute vaso-occlusive crisis, complications, and chronic sequelae

Sickle cell disease (SCD) is the most prevalent hemoglobinopathy. Survival in patients with SCD has improved over the past few decades. These patients experience a lifetime of repeated acute pain crises, which are thought to result from sickling and microvascular occlusions; acute abdominal pain is common. Moreover, repeated crises often lead to organ dysfunction, such as asplenia, hepatic failure, and renal failure. The spleen, liver, biliary system, kidneys, and gastrointestinal tract can all be affected. Patients may undergo CT to further direct clinical management. We review the spectrum of CT imaging findings of abdominal manifestations in patients with SCD, from the acute microvascular occlusive pain crisis to the potential complications and chronic sequelae.

Acute gastrointestinal vaso-occlusive ischemia in sickle cell disease: CT imaging features and clinical outcome

PURPOSE

The purpose of this study was to determine the incidence, specific imaging features, and outcome of gastrointestinal vaso-occlusive ischemia (GVOI) in sickle cell patients undergoing CT for acute abdominal pain.

METHODS

This HIPAA-compliant, IRB-approved retrospective study evaluated sickle cell patients with an abdominal pain crisis and acute gastrointestinal abnormalities on CT from 1/2006 to 1/2014. CT findings were divided into those compatible and incompatible with bowel ischemia or clinical diagnosis of GVOI. Two abdominal radiologists (1, 13 years' experience) reviewed the CTs for specific imaging features of ischemia. Clinical laboratory values (lactate, WBC) and outcome were recorded. Descriptive statistics and Wilcoxon-Mann-Whitney two-sample rank-sum test were performed.

RESULTS

Of 217 CTs, 33 had acute gastrointestinal abnormalities: 75% (25/33) consistent with ischemia and clinical GVOI. Complications of ischemia occurred in 16% (4/25): ileus (50%), perforation (25%), and pneumatosis (25%). In uncomplicated cases, all had bowel wall thickening: segmental 52% (11/21) or diffuse 48% (10/21). The colon was commonly involved (76%, 16/21), particularly the ascending (57%, 12/21). Most abnormalities (52%, 11/21) were in the superior mesenteric artery distribution. Average lactate (4.3 ± 4.0 mmol/L, p = 0.02) and WBC count (20.1 ± 10.4, ×1000 cells/μL, p = 0.01) were significantly higher in GVOI. Overall mortality in patients with GVOI was 17% (3/18).

CONCLUSION

GVOI is an important feature of the acute abdominal crisis in patients with sickle cell disease and can be seen in up to 75% of patients with abnormal bowel findings on CT. The diagnosis should be strongly considered in sickle cell patients with CT findings of diffuse or segmental bowel wall thickening, particularly involving the colon.

Spontaneous Intramural Intestinal Hemorrhage versus Acute Mesenteric Ischemia by CT Evaluation

Objective The purpose of our study was to differentiate the imaging findings of patients with spontaneous intramural intestinal hemorrhage (SIIH) from those with acute mesenteric ischemia (AMI) after abdominal computed tomography (CT) survey in the emergency department. Methods We retrospectively included 83 patients diagnosed with SIIH or AMI after abdominal CT. Results The mean ages of 30 SIIH patients and 53 AMI patients were 74.4±14.6 years and 75.8±11.2 years, respectively. Patients with SIIH had significantly thicker maximal intestinal wall thickening (14.8±3.9 vs. 10.9 ±4.1, p<0.001), a lower rate of ileum involvement (26.7% vs. 77.4%, p<0.001) and a higher rate of ascites (96.7% vs. 64.2%, p<0.001) compared with patients with AMI. Neither pneumatosis intestinalis (p<0.001) nor portomesenteric gas (p<0.01) were detected in SIIH patients but were observed in AMI patients. A receiver-operating characteristic (ROC) curve analysis showed that the optimal cut-off value for maximal intestinal wall thickening between groups was 10.4 mm and the area under the ROC curve between groups was 0.752 (p<0.0001). A multiple logistic regression analysis showed that the independent predictors of SIIH were non-involvement of the ileum (odds ratio, OR, 6.998; p=0.001), maximal intestinal wall thickening ≥10.4 mm (OR, 5.748; p=0.040) and ascites (OR, 13.348; p=0.023). The area under the ROC curve for the model was 0.854 (p<0.001). Conclusion The independent predictors of SIIH from AMI after abdominal CT in acute abdominal patients include non-involvement of the ileum, intestinal wall thickening ≥10.4 mm, and ascites.

CT of Gastrointestinal Vasoocclusive Crisis Complicating Sickle Cell Disease

OBJECTIVE

The purposes of this article are to illustrate the CT appearance of gastrointestinal vasoocclusive crisis in patients with sickle cell disease (SCD), highlight potential complications, and review other conditions that may have similar findings.

CONCLUSION

The gastrointestinal vasoocclusive crisis in SCD is rare but can result in potentially life-threatening ischemia and death. Knowledge of the spectrum of CT features of the gastrointestinal vasoocclusive crisis is important in making the diagnosis and potentially preventing complications.

Gastrointestinal intramural hematoma--analysis of clinical and radiological features for early differentiation from mesenteric ischemia

INTRODUCTION

Long-term anticoagulation is associated with hemorrhage at various sites. Gastrointestinal intramural bleeds and hematomas (IMH) often mimic mesenteric ischemia (MI) due to similar clinical settings and imaging features, making early differentiation difficult.

AIM

To compare the demography, clinical features and imaging characteristics of patients presenting with IMH with those of MI, so as to help in evolving clinical and imaging guidelines to differentiate both early in the course of the disease.

METHODS

All radiologically (contrast-enhanced computed tomogram [CT]) diagnosed cases of gastrointestinal IMH from the hospital database during the period between 2006 and 2012 were retrospectively analyzed. This data was compared with the clinical and imaging features of a group of surgically confirmed MI during the same period. Patients not on anticoagulation therapy at the time of presentation and those with incomplete clinical or radiological data were excluded from the study.

RESULTS

There were 16 patients in IMH group and 54 patients in MI group. Clinical features like overt rectal bleeding or melena, and prolonged prothrombin time-international normalized ratio (PT-INR) more than three, and CT features like proximal location in the bowel, increased bowel wall thickness, hyperdensity on plain scan (>40 Hounsfield units (HU)), and short segment bowel involvement were significantly associated with IMH. Visualization of embolus and absent mesenteric vasculature to a segment of intestine in CT was significantly associated with MI.

CONCLUSION

Attention to clinical features and early CT scan can aid in early differentiation of IMH from MI, facilitating appropriate intervention early in the course of disease.

A spontaneous strangulated transomental hernia: Prospective and retrospective multi-detector computed tomography findings

Transomental hernias are among the rarest type of all internal hernias which overall account for less than 6% of small bowel obstructions. Most transomental hernias occurring in adults are either iatrogenic or post-traumatic. More rarely, a spontaneous herniation of small bowel loops may result from senile atrophy of the omentum. We report a case of an 86-year-old male who presented with signs and symptoms of small bowel obstruction but had no past surgical or traumatic abdominal history. At contrast-enhanced multi-detector row computed tomography (CT), a cluster of fluid-filled dilated small bowel loops could be appreciated in the left flank, with associated signs of bowel wall ischemia. Swirling of the mesenteric vessels could also be appreciated and CT findings were prospectively considered consistent with a strangulated small bowel volvulus. At laparotomy, no derotation had to be performed but up to 100 cm of gangrenous small bowel loops had to be resected because of a transomental hernia through a small defect in the left part of the greater omentum. Retrospective reading of CT images was performed and findings suggestive of transomental herniation could then be appreciated.

How to differentiate spontaneous intramural intestinal hemorrhage from acute mesenteric ischemia

OBJECTS

The purpose of our study was to assess the diagnostic values of laboratory tests to differentiate spontaneous intramural intestinal hemorrhage (SIIH) from acute mesenteric ischemia (AMI) after abdominal computed tomography (CT) survey in the emergency department (ED).

METHOD

We retrospectively included 76 patients diagnosed SIIH or AMI after abdominal CT.

RESULTS

The mean ages of 28 SIIH patients and 48 AMI patients were 75.9 ± 13.7 years and 75.8 ± 11.6 years, respectively. Patients with SIIH had significantly higher rate of Coumadin use (P < .001) and localized tenderness (P < .05). In laboratory findings, SIIH patients had prolonged prothrombin time (PT) (83.6 ± 30.0 vs. 13.4 ± 3.2, P < .001), lower blood urea nitrogen (P < .05), lower creatinine (P < .05), and lower creatine kinase (P < .05). Prolonged PT showed good discriminative value to differentiate acute abdomen patients with SIIH from AMI after abdominal CT, with an area under the receiver operating characteristic curve of 0.980 (95% confidence interval, 0.918-0.998; P < .0001). Prolonged PT cut-off value of ≧22.5 seconds had a sensitivity of 92.9% and a specificity of 100%. Logistic regression analysis identified prolonged PT as an independent predictor of SIIH (odds ratio, OR, 22.2; P = .007).

CONCLUSION

Abdominal pain patients with either SIIH or AMI are rare in the ED, but abdominal CT sometimes cannot help to differentiate them due to similar CT findings. Prolonged PT might help emergency physicians and surgeons differentiate SIIH from AMI in such cases.

Small bowel intramural hematoma secondary to abdominal massage

Oral anticoagulant therapy with warfarin is commonly used to prevent thromboembolic event in patients at risk with atrial fibrillation [1]. Spontaneous intramural hematoma of small intestine is rare complication of anticoagulant therapy and occurs in patient who receives excessive warfarin that may result in potentially serious complications. Small bowel intramural hematoma secondary to warfarin therapy is a recognized complication [2]. In the present report, we report an unusual case of small bowel intramural hemorrhage secondary to anticoagulant therapy after abdominal massage. The emergency physicians should be aware that the potential spontaneous small bowel intramural hemorrhage in the patients has a high index of suspicion because most patients are treated nonoperatively with a good outcome.

Hemorrhagic complications of anticoagulant therapy: role of multidetector computed tomography and spectrum of imaging findings from head to toe

Highly effective in preventing and treating thromboembolic conditions in acute and chronic settings, anticoagulant therapy is associated with a non-negligible risk of hemorrhagic complications with a considerable clinical impact. Advanced age and comorbidities further increase the risk of bleeding during heparinization, treatment with low-molecular-weight heparins or long-term oral warfarin anticoagulation. Multidetector computed tomography represents the mainstay diagnostic technique to image-suspected hemorrhages in anticoagulated patients, as it can quickly assess presence, site, and extent of hemorrhage, identify active bleeding, and possible underlying diseases. Cross-sectional imaging appearances of the wide spectrum of anticoagulant therapy-related bleeding complications are hereby presented, including peripheral and thoracic-abdominal wall muscular hematomas, intrathoracic, abdominal, retroperitoneal genitourinary, gastrointestinal, and brain hemorrhages. Prompt recognition and comprehensive diagnostic assessment with multidetector computed tomography allow clinicians to correctly choose treatment modification or withdrawal, surgery, or interventional procedures as needed, with the aim to reduce the associated morbidity and mortality.

Utility of arterial phase of dynamic CT for detection of intestinal ischemia associated with strangulation ileus

AIM: To clarify the usefulness of arterial phase scans in contrast computed tomography (CT) imaging of strangulation ileus in order to make an early diagnosis.

METHODS: A comparative examination was carried out with respect to the CT value of the intestinal tract wall in each scanning phase, the CT value of the content in the intestinal tract, and the CT value of ascites fluid in the portal vein phase for a group in which ischemia was observed (Group I) and a group in which ischemia was not observed (Group N) based on the pathological findings or intra-surgical findings. Moreover, a comparative examination was carried out in Group I subjects for each scanning phase with respect to average differences in the CT values of the intestinal tract wall where ischemia was suspected and in the intestinal tract wall in non-ischemic areas.

RESULTS: There were 15 subjects in Group I and 30 subjects in Group N. The CT value of the intestinal tract wall was 41.8 ± 11.2 Hounsfield Unit (HU) in Group I and 69.6 ± 18.4 HU in Group N in the arterial phase, with the CT value of the ischemic bowel wall being significantly lower in Group I. In the portal vein phase, the CT value of the ischemic bowel wall was 60.6 ± 14.6 HU in Group I and 80.7 ± 17.7 HU in Group N, with the CT value of the ischemic bowel wall being significantly lower in Group I; however, no significant differences were observed in the equilibrium phase. The CT value of the solution in the intestine was 18.6 ± 9.5 HU in Group I and 10.4 ± 5.1 HU in Group N, being significantly higher in Group I. No significant differences were observed in the CT value of the accumulation of ascites fluid. The average difference in the CT values between the ischemic bowel wall and the non-ischemic bowel wall for each subject in Group I was 33.7 ± 20.1 HU in the arterial phase, being significantly larger compared to the other two phases.

CONCLUSION: This is a retrospective study using a small number of subjects; however, it suggests that there is a possibility that CT scanning in the arterial phase is useful for the early diagnosis of strangulation ileus.

Acute bowel ischemia: analysis of diagnostic error by overlooked findings at MDCT angiography

To retrospectively evaluate the frequency and type of findings that were missed in the original reports of multi-detector CT angiography (MDCTA) in patients with suspected acute bowel ischemia. From January 2007 to March 2011, a series of 35 patients who underwent MDCTA of the abdomen and pelvis and had surgery were included. The reports of the initial CT were retrospectively compared with the discharge diagnosis and surgical reports. Discrepant or missing findings were re-evaluated and divided into relevant or not relevant regarding the diagnosis. In 23 of the 35 patients (66 %), all findings were correctly diagnosed in the initial MDCTA report. In the remaining 12 of the 35 patients (34 %), lesions that were not reported were present at surgery. In 10 of the 12 (83 %) patients, the overlooked findings were relevant and subtle: gas in the portal vein (n = 3), gas in the bowel wall (n = 3), gas in the portal vein and bowel wall (n = 2), thrombotic occlusion of the superior mesenteric artery (n = 1), and thrombotic occlusion of the inferior mesenteric artery (n = 1). In 2 of the 12 (17 %) patients in whom the MDCTA-overlooked findings were classified as non-relevant, bowel ischemia was found at surgery. With retrospective image interpretation, 83 % of the patients with occlusive mesenteric ischemia at surgery were correctly identified, whereas the remaining 17 % with non-occlusive mesenteric ischemia at surgery showed non-relevant findings at MDCTA. About 33 % of relevant findings of bowel ischemia were overlooked by the initial MDCTA interpretation, most were subtle findings. However, secondary reading revealed most of these findings and can serve to improve diagnostic performance.

CT findings of small bowel strangulation: the importance of contrast enhancement

The purpose of this study is to illustrate computed tomography (CT) findings suggestive of small bowel strangulation. We have performed the precontrast and postcontrast CT with single and multidetector CT scanners and evaluated the bowel wall changes and mesentery changes and correlated them with the operative findings. The direct CT findings suggestive of small bowel strangulation included high-density bowel wall on precontrast scans; lack of, or diminished contrast enhancement of the involved bowel wall; localized mesenteric fluid accumulation (mesenteric congestion); and localized pneumatosis. The indirect CT signs included C- or U-shaped loops with mesenteric vessels converging toward the obstruction site, ascites, target sign, two adjacent collapsed round loops, and whirl sign. We particularly emphasize the importance of contrast enhancement of bowel mucosa for early diagnosis to differentiate strangulation from a mechanical obstruction without bowel ischemia, and also the importance to differentiate proximal secondary gas-filled dilated small bowel loops from distal primary involved fluid-filled small bowel loops because these two types of small bowel loops are present in the single peritoneal cavity. As early recognition of small bowel strangulation may help improve the patient outcome because the involved bowel loops can be preserved without resection, it is essential to become familiar with the CT signs suggested small bowel obstruction strangulation.

CT enterography: review of technique and practical tips

CT enterography is a new non-invasive imaging technique that offers superior small bowel visualisation compared with standard abdomino-pelvic CT, and provides complementary diagnostic information to capsule endoscopy and MRI enterography. CT enterography is well tolerated by patients and enables accurate, efficient assessment of pathology arising from the small bowel wall or surrounding organs. This article reviews the clinical role of CT enterography, and offers practical tips for optimising technique and accurate interpretation.

Multidetector CT imaging in mesenteric ischemia--pearls and pitfalls

Mesenteric ischemia is a complex and devastating disease which still remains a diagnostic challenge to the clinicians due to non-specific clinical and laboratory findings. Several imaging features have been described with multidetector computed tomography which allows the diagnosis of mesenteric ischemia with high sensitivity and specificity. However, there are imaging features which overlap with other pathologies including benign inflammation and infection. Knowledge of imaging findings in mesenteric ischemia and its potential mimics is important in early and definitive diagnosis.

Anticoagulant-induced intramural intestinal hemorrhage

BACKGROUND

Long-term use of warfarin can provide benefits in the treatment of many diseases, but adverse bleeding events are unpreventable because of a narrow therapeutic range.

OBJECTIVE

The aim of this retrospective chart review with data abstraction was to investigate the clinical presentations of intestinal intramural hemorrhage in emergency department (ED) patients.

METHODS

We reviewed the cases of 17 patients with acute abdominal pain in our ED. Medical records including demographic data and results of abdominal computed tomography were retrospectively reviewed and analyzed.

RESULTS

The mean ± SD age of the reviewed patients was 77.7 ± 8.5 years (range, 60-93 years). The mean ± SD duration from onset of symptoms to ED visit was 2.5 ± 1.3 days (range, 1-5 days). All patients had abdominal pain, and 64.7% had nausea/vomiting. A total of 64.7% of patients had peritoneal signs. The jejunum was most commonly involved (88.2% of all cases). The maximal mean ± SD wall thickening of the bowel was 14.1 ± 4.4 mm (range, 7.4-26.7 mm), and the estimated mean ± SD length was 35.6 ± 24.4 cm (range, 9-105 cm). The mean ± SD prothrombin time and activated partial thromboplastin time were prolonged to 86.5 ± 26.9 and 116.2 ± 43.1 seconds, respectively. All patients received medical treatment and survived. At the last follow-up (mean, 27.4 months), none of the patients had recurrence of intestinal intramural hemorrhage or intestinal obstruction.

CONCLUSION

Prolonged prothrombin time and drug history can indicate the possibility of intramural intestinal hemorrhage, and abdominal computed tomography may help to exclude surgical diseases and prevent unnecessary surgery.

Spectrum of CT findings in patients with atrial fibrillation and nontraumatic acute abdomen

OBJECTIVE

The purpose of our study was to review the wide spectrum of pertinent CT findings in patients with acute nontraumatic abdominal pain in the setting of atrial fibrillation.

CONCLUSION

Underlying embolic or hemorrhagic complications are common in patients with acute nontraumatic abdominal pain in the setting of atrial fibrillation and can be accurately seen on CT.

Computed tomography of the acute abdomen in patients with atrial fibrillation

OBJECTIVE

To investigate the frequency and basis of clinically relevant computed tomographic (CT) findings in patients with atrial fibrillation and acute abdominal pain.

MATERIALS AND METHODS

We retrospectively identified 30 patients with atrial fibrillation referred for enhanced (n = 26) or unenhanced (n = 4) abdominal CT from our emergency department because of acute nontraumatic abdominal pain. All CT images were independently reviewed by a single reader who evaluated the studies for findings that might explain acute pain. Results were correlated with laboratory and surgical findings, clinical course and outcome, and final diagnosis.

RESULTS

Eleven (37%) of the 30 patients had CT findings for abdominal pain that related to atrial fibrillation, including end-organ ischemia or infarction (n = 8, 27%) and spontaneous hemorrhage presumably related to anticoagulation (n = 3, 10%). Of the remaining patients, 5 (17%) had nonatrial fibrillation-related CT findings for abdominal pain, and 14 (47%) had no cause for abdominal pain found at CT.

CONCLUSIONS

Patients with atrial fibrillation who present to CT with acute abdominal pain have a high likelihood of being found with abdominal pathology relating to their atrial fibrillation, such as arterial embolus or hemorrhage, and a lower likelihood of having more typical causes for abdominal pain. Increased awareness of the high likelihood of atrial fibrillation-related causes for abdominal pain may improve diagnoses and triage for this special and difficult population.

Differential diagnosis of small bowel ischemia

This article presents the differential diagnosis for small bowel ischemia. Clinical presentation of small bowel ischemia is variable, presenting with a myriad of specific or nonspecific clinical and laboratory findings. The imaging findings associated with small bowel ischemia are variable and combinations of findings may be necessary for definitive diagnosis. More specific imaging findings in patients with acute small intestine ischemia include bowel wall gas, mesenteric vessel occlusion, mesenteric venous gas, portal venous gas, or absence of bowel wall enhancement. Less specific imaging findings include small bowel wall thickening, mesenteric stranding, and mesenteric fluid. Further complicating the issue, several small intestinal disease processes may mimic ischemia both clinically and radiographically. These alternate diagnoses include infectious, inflammatory, and infiltrative processes.

Imaging in intestinal ischemic disorders

Intestinal ischemia and infarction are a heterogeneous group of diseases that have as their unifying theme hypoxia of the small bowel or colon. The incidence of bowel ischemia and infarction is on the rise for several reasons: the aging of the population, the ability of intensive care units to salvage critically ill patients, and heightened clinical awareness of these disorders. Improvements in diagnostic imaging techniques have greatly contributed to the earlier diagnosis of intestinal ischemia, which can have a positive influence on patient outcomes. In this article, role of radiology in the detection, differential diagnosis, and management of patients who have intestinal ischemia and infarction is discussed.

CT evaluation of shock viscera: a pictorial review

The purpose of this article is to review both the pathophysiology and the computed tomography features of the hypoperfusion complex and shock viscera. The main findings include dilated fluid-filled loops of bowel with hyperenhancing mucosa, intensely enhancing kidneys and mesenteric vasculature, and small caliber, dense aorta and collapsed, slit-like inferior vena cava. Variable features include increased enhancement of the adrenals, decreased enhancement of the spleen, and altered enhancement of the pancreas with both hypo- and hyperenhancement described. This complex of findings indicates a tenuous hemodynamic status and has been associated with a poor prognosis. In addition, it is important to discern this collection of findings from direct injury to the viscera to aid in appropriate triage and management of the patients' injuries.

[Spontaneous intramural small bowel hemorrhage: an event on the increase]

Spontaneous intramural intestinal hemorrhage is highly infrequent. The most common cause is overdose of oral anticoagulants. Clinical presentation usually consists of abdominal pain and intestinal obstruction. The diagnostic imaging technique of choice is computed tomography. Spontaneous intramural intestinal hemorrhage usually resolves spontaneously and consequently the treatment of choice is non-operative. Surgery is reserved for complicated processes or when the diagnosis is uncertain. We present two cases. The first was due to overanticoagulation by acenocoumarol, and the second was an exceptional complication in a hemophiliac patient.

A pattern approach to the abnormal small bowel: observations at MDCT and CT enterography

OBJECTIVE

Imaging of the vast array of pathologic processes occurring in the small bowel has been facilitated by recent advances, including the use of MDCT scanners that acquire isotropic data and neutral oral contrast agents that improve small-bowel distention.

CONCLUSION

This review shows how a systematic pattern approach can be used to narrow the differential diagnosis when an abnormal small-bowel loop is detected on MDCT.

The acute right lower quadrant

Acute right lower quadrant pain is a nonspecific but common clinical complaint. Appendicitis is the most common cause of acute right lower quadrant pain and CT has become the most reliable imaging method in the evaluation of these patients. Although there is controversy regarding the best way to perform CT in this setting, oral and i.v. contrast-enhanced CT remains the most commonly used technique. CT with oral and i.v. contrast material facilitates diagnosis of appendicitis and the numerous other entities that may cause right lower quadrant pain.

Acute small bowel ischemia: CT imaging findings

Small bowel ischemia is a disorder related to a variety of conditions resulting in interruption or reduction of the blood supply of the small intestine. It may present with various clinical and radiologic manifestations, and ranges pathologically from localized transient ischemia to catastrophic necrosis of the intestinal tract. The primary causes of insufficient blood flow to the small intestine are various and include thromboembolism (50% of cases), nonocclusive causes, bowel obstruction, neoplasms, vasculitis, abdominal inflammatory conditions, trauma, chemotherapy, radiation, and corrosive injury. Computed tomography (CT) can demonstrate changes because of ischemic bowel accurately, may be helpful in determining the primary cause of ischemia, and can demonstrate important coexistent findings or complications. However, common CT findings in acute small bowel ischemia are not specific and, therefore, it is often a combination of clinical, laboratory and radiologic signs that may lead to a correct diagnosis. Understanding the pathogenesis of various conditions leading to mesenteric ischemia and being familiar with the spectrum of diagnostic CT signs may help the radiologist recognize ischemic small bowel disease and avoid delayed diagnosis. The aim of this article is to provide a review of the pathogenesis and various causes of acute small bowel ischemia and to demonstrate the contribution of CT in the diagnosis of this complex disease.