CT findings in acute, subacute, and chronic ischemic colitis: suggestions for diagnosis. Biomed Res Int. 2014;2014:895248. [PMID: 25247191 DOI: 10.1155/2014/895248]

Abdominal compartment syndrome: what radiologist needs to know

The intra-abdominal hypertension (IAH) and the abdominal compartment syndrome (ACS) are life-threatening conditions with a significant rate of mortality; therefore, early detection is paramount in their optimal management. IAH is diagnosed when the intra-abdominal pressure (IAP) is more than 12 mmHg. It can occur when the intra-abdominal volume increases (ileus, ascites, trauma, pancreatitis, etc.) and/or the abdominal wall compliance decreases. IAH can cause decreased venous flow, low cardiac output, renal impairment, and decreased respiratory compliance. Consequently, these complications can lead to multiple organ failure and induce the abdominal compartment syndrome (ACS) when IAP rises above 20 mmHg. The diagnosis is usually made with intravesical pressure measurement. However, this measurement was not always possible to obtain; therefore, alternative diagnostic techniques should be considered. In this setting, computed tomography (CT) may play a crucial role, allowing the detection and characterization of pathological conditions that may lead to IAH. This review is focused on the pathogenesis, clinical features, and radiological findings of ACS, because their presence allows radiologists to raise the suspicion of IAH/ACS in critically ill patients, guiding the most appropriate treatment.

Insights into acute mesenteric ischaemia: an up-to-date, evidence-based review from a mesenteric stroke centre unit

Radiologists play a central role in the diagnostic and prognostic evaluation of patients with acute mesenteric ischaemia (AMI). Unfortunately, more than half of AMI patients undergo imaging with no prior suspicion of AMI, making identifying this disease even more difficult. A confirmed diagnosis of AMI is ideally made with dynamic contrast-enhanced CT but the diagnosis may be made on portal-venous phase images in appropriate clinical settings. AMI is diagnosed on CT based on the identification of vascular impairment and bowel ischaemic injury with no other cause. Moreover, radiologists must evaluate the probability of bowel necrosis, which will influence the treatment options.AMI is usually separated into different entities: arterial, venous, non-occlusive and ischaemic colitis. Arterial AMI can be occlusive or stenotic, the dominant causes being atherothrombosis, embolism and isolated superior mesenteric artery (SMA) dissection. The main finding in the bowel is decreased wall enhancement, and necrosis can be suspected when dilatation >25 mm is identified. Venous AMI is related to superior mesenteric vein (SMV) thrombosis as a result of a thrombophilic state (acquired or inherited), local injury (cancer, inflammation or trauma) or underlying SMV insufficiency. The dominant features in the bowel are hypoattenuating wall thickening with submucosal oedema. Decreased enhancement of the involved bowel suggests necrosis. Non-occlusive mesenteric ischaemia (NOMI) is related to impaired SMA flow following global hypoperfusion associated with low-flow states. There are numerous findings in the bowel characterised by diffuse extension. An absence of bowel enhancement and a thin bowel wall suggest necrosis in NOMI. Finally, ischaemic colitis is a sub-entity of arterial AMI and reflects localised colon ischaemia-reperfusion injury. The main CT finding is a thickened colon wall with fat stranding, which seems to be unrelated to SMA or inferior mesenteric artery lesions. A precise identification and description of vascular lesions, bowel involvement and features associated with transmural necrosis is needed to determine patient treatment and outcome.

The Role of CT-Angiography in the Acute Gastrointestinal Bleeding: A Pictorial Essay of Active and Obscure Findings

Gastrointestinal bleeding is a potentially life-threatening abdominal emergency that remains a common cause of hospitalisation. Although 80–85% of cases of gastrointestinal bleeding resolve spontaneously, it can result in massive haemorrhage and death. The presentation of gastrointestinal bleeding can range from asymptomatic or mildly ill patients requiring only conservative treatments to severely ill patients requiring immediate intervention. Identifying the source of the bleeding can be difficult due to the wide range of potential causes, the length of the gastrointestinal tract and the intermittent nature of the bleeding. The diagnostic and therapeutic approach is fully dependent on the nature of the bleeding and the patient’s haemodynamic status. Radiologists should be aware of the appropriate uses of computed tomography angiography and other imaging modalities in patients with acute gastrointestinal bleeding, as well as the semiotics of bleeding and diagnostic pitfalls in order to appropriately diagnose and manage these patients. The learning objective of this review is to illustrate the computed tomography angiography technique, including the potential role of dual-energy computed tomography angiography, also highlighting the tips and tricks to identify the most common and uncommon features of acute gastrointestinal bleeding and its obscure form.

Mesenteric ischemia: a radiologic perspective

Mesenteric ischemia is a broad term encompassing several clinical conditions leading to impaired vascularity of bowel loops. Absence of specific clinical presentation and a definitive laboratory marker often lead to delayed diagnosis with high morbidity and mortality in the acute setting. Imaging plays a crucial role in the diagnosis and management. Multi-detector CT (MDCT) is the first line imaging modality for the evaluation of patients with suspected mesenteric ischemia and plays an important role for assessing its severity and complications. This review article highlights the causes, pathophysiology, imaging features and possible endovascular treatment options of mesenteric ischemia.

Role of multidetector computed tomography in patients with acute infectious colitis

BACKGROUND

The role of multidetector computed tomography (MDCT) in patients with acute infectious colitis is still unclear.

AIM

To examine the usefulness of MDCT in distinguishing the etiology of acute infectious colitis.

METHODS

Overall, 244 patients who met the criteria for acute infectious colitis and visited the Hospital from February 2015 to 2018 were retrospectively enrolled and divided into two groups (bacterial: 204, viral: 40) according to causes of acute colitis, based on stool PCR. Eleven MDCT parameters, including wall thickening, submucosal edema, mucosal enhancement, serosa involvement, empty colon sign, small bowel involvement, comb sign, continuous distribution, accordion sign, mucosal thickening, and lymph node enlargement, were constructed in a blinded fashion.

RESULTS

MDCT parameters of wall thickening (OR: 13.60; 95%CI: 5.80–31.88; P < 0.001), submucosal edema (OR: 36.08; 95%CI: 13.54–96.13; P < 0.001), mucosal enhancement (OR: 22.55; 95%CI: 9.28–54.81; P < 0.001), serosal involvement (OR: 14.50; 95%CI: 3.33–63.23; P < 0.001), empty colon sign (OR: 6.68; 95%CI: 2.44–18.32; P < 0.001), continuous distribution (OR: 24.09; 95%CI: 9.38–61.90; P < 0.001), accordion sign (OR: 9.02; 95%CI: 1.12–72.35; P = 0.038), mucosal thickening (OR: 46.41; 95%CI: 10.38–207.51; P < 0.001), and lymph node enlargement (OR: 4.39; 95%CI: 1.22–15.72; P = 0.023) were significantly associated with bacterial colitis. At least one positive finding in four CT outcomes (submucosal edema, mucosal enhancement, continuous distribution, mucosal thickening) in summer showed a high probability of bacterial colitis (sensitivity, 41.67; specificity, 92.50; OR: 24.95).

CONCLUSION

MDCT provides many clues that can be useful in suggesting a specific etiology of acute infectious colitis.

ECCO Topical Review on Clinicopathological Spectrum and Differential Diagnosis of Inflammatory Bowel Disease

INTRODUCTION

Many diseases can imitate inflammatory bowel disease [IBD] clinically and pathologically. This review outlines the differential diagnosis of IBD and discusses morphological pointers and ancillary techniques that assist with the distinction between IBD and its mimics.

METHODS

European Crohn's and Colitis Organisation [ECCO] Topical Reviews are the result of an expert consensus. For this review, ECCO announced an open call to its members and formed three working groups [WGs] to study clinical aspects, pathological considerations, and the value of ancillary techniques. All WGs performed a systematic literature search.

RESULTS

Each WG produced a draft text and drew up provisional Current Practice Position [CPP] statements that highlighted the most important conclusions. Discussions and a preliminary voting round took place, with subsequent revision of CPP statements and text and a further meeting to agree on final statements.

CONCLUSIONS

Clinicians and pathologists encounter a wide variety of mimics of IBD, including infection, drug-induced disease, vascular disorders, diverticular disease, diversion proctocolitis, radiation damage, and immune disorders. Reliable distinction requires a multidisciplinary approach.

Colon ischemia: A comprehensive review

The clinical and endoscopic features of colon ischemia (CI) are non-specific. CI is correctly identified at the time of presentation in only 9% of patients is. The true incidence is likely underestimated because many mild cases resolve spontaneously without medical treatment. Furthermore, since most cases of CI are transient, and no specific cause is detected they are often considered to be "idiopathic". In the setting of severe CI correct diagnosis and prompt recognition and therapy as well as identification of underlying causes are crucial for a favourable outcome. Although less severe, mild cases may present with similar symptoms, the prognosis and management are completely different and managed conservatively rather than with surgery. Unfortunately, data from most studies and current guidelines do not provide recommendations on the long-term management of CI or about the need for endoscopic follow-up to detect the development chronic, recurrent and/or ischemic colonic strictures. In this review, we focus on the definition of CI, its aetiology, and patterns of presentation. We highlight the pharmacological and/or endoscopic management as determined severity of disease that allow for improved outcomes. Prompt recognition and treatment using a multidisciplinary approach are essential for successful management of severe CI because mortality rates are significantly higher when the diagnosis is delayed.

Usefulness of damage control approach in patients with limited acute mesenteric ischemia: a prospective study of 85 patients

To evaluate the efficacy of the damage control approach by two-step surgical procedure in not critical patients (without sepsis or septic shock) with peritonitis from limited acute mesenteric ischemia. From April 2013 to April 2020, 85 patients [49 (57.7%) women and 36 (42.3%) men, median age 69.5 (range 38-92)] were enrolled in this study and underwent emergency surgery. After resection of ischemic bowel, basing on the individual decision of the single surgeon, the patients underwent primary end-to-end anastomosis (Group 1) or damage control approach (Group 2) including primary laparotomy with resection of ischemic bowel, temporary abdominal closure and a second-look procedure at 48 h with re-evaluation of bowel vitality. Forty-seven (55.3%) patients underwent one-stage surgical treatment and 38 (44.7%) patients received a two-step procedure. In the latter group, at second exploration, 8 (21%) patients required a further intestinal resection, due to mesenteric ischemia progression. Both anastomosis dehiscence rate and need for ileostomy in Group 1 patients were significantly higher than in Group 2 (23.4% vs 5.3%: p = 0.03 and 19.1% vs 2.6%: p = 0.03; Fisher's exact test). No significative differences in mortality and morbidity rate were found between the two groups. The damage control approach by two-step surgical procedure may represent a valid innovative option in the management of not critical patients with limited acute mesenteric ischemia, achieving a better clinical outcome if compared with surgical treatment by one-step procedure.

A Novel Multiparameter Scoring Model for Noninvasive Early Prediction of Ischemic Colitis: A Multicenter, Retrospective, and Real-World Study

INTRODUCTION

Ischemic colitis (IC) is a common gastrointestinal ischemic disease caused by hypoperfusion or reperfusion injury. However, there are few studies on risk factors associated with poor prognoses of the disease. This study aimed to determine the predictors of poor prognoses in patients with IC and establish a prognostic scoring method with good internal and external validity for identifying severe cases in an early stage.

METHODS

We established a prognosis model by conducting a multicenter, retrospective study of patients hospitalized with IC between November 2008 and May 2020. Predictive power was tested using 5-fold internal cross-validation and external validation.

RESULTS

The following 6 factors were included in the prognostic model: neutrophil count, D-dimer level, ischemia of the distal ileum, ischemia of the hepatic flexure, ulceration, and luminal stenosis. The area under the receiver-operating characteristic curve for internal cross-validation of the prediction model was 86%, and that for external validation was 95%. During internal validation, our model correctly identified 88.08% of the patients. It was further found that patients younger than 65 years with a higher neutrophil-to-lymphocyte ratio and higher heart rate had poor prognoses. Patients aged 65 years and older with ischemia of terminal ileum, hepatic flexure, splenic flexure, and intestinal stenosis had poor prognoses.

DISCUSSION

Patients with ischemia in the hepatic flexure and the distal ileum, endoscopic evidence of ulcer or stenosis, higher neutrophil counts, and higher D-dimer levels have worse prognoses. This information could aid in the selection of timely and appropriate treatment.

Large Bowel Ischemia/Infarction: How to Recognize It and Make Differential Diagnosis? A Review

Ischemic colitis represents the most frequent form of intestinal ischemia occurring when there is an acute impairment or chronic reduction in the colonic blood supply, resulting in mucosal ulceration, inflammation, hemorrhage and ischemic necrosis of variable severity. The clinical presentation is variable and nonspecific, so it is often misdiagnosed. The most common etiology is hypoperfusion, almost always associated with generalized atherosclerotic disease. The severity ranges from localized and transient ischemia to transmural necrosis of the bowel wall, becoming a surgical emergency, with significant associated morbidity and mortality. The diagnosis is based on clinical, laboratory suspicion and radiological, endoscopic and histopathological findings. Among the radiological tests, enhanced-CT is the diagnostic investigation of choice. It allows us to make the diagnosis in an appropriate clinical setting, and to define the entity of the ischemia. MR may be adopted in the follow-up in patients with iodine allergy or renal dysfunctions, or younger patients who should avoid radiological exposure. In the majority of cases, supportive therapy is the only required treatment. In this article we review the pathophysiology and the imaging findings of ischemic colitis.

Diagnostic methods and drug therapies in patients with ischemic colitis

PURPOSE

Ischemic colitis (IC) is the most prevalent ischemic injury of thegastrointestinal tract. Clinical features of IC such as acute abdominal pain, hematochezia,and diarrhea are similar to those of acute mesenteric ischemia, inflammatorybowel disease, or infectious bowel disease, and their relative ambiguity candelay diagnosis and treatment. To comprehensively detail the current state ofdiagnostic methods and available drug therapies for detecting and treating IC,this review aims to provide a concise and practical summary of thecorresponding literature.

METHODS

PubMed and Cochrane Library were searched toretrieve all published studies reporting the diagnostic methods and drugtherapies in patients with ischemic colitis. The search strategy of drugtherapy includes human and animal data.

RESULTS

Colonoscopy combined with histopathologicalbiopsy is the standard of diagnosis for the IC. Most patients respond well tothe conservative treatment, and surgical consultation is needed when conservativetreatment is ineffective. Studies of potential drug therapy have beendeveloped, including phosphodiesterase type 5 inhibitors, pentoxifylline,rebamipide, prostaglandin E1, and polydeoxyribonucleotide.

CONCLUSION

Accurate diagnoses and effective treatmentshave helped reduce the mortality rate and improve prognoses for patientsafflicted with IC, and corresponding drug therapies have been constantlyupdated as new research has emerged.

Inflammatory Bowel Diseases and Coexisting Spondyloarthritis: A Neglected and too Often Under-Reported Association by Radiologists. A Multicenter Study by Italian Research Group of Imaging in Rheumatology

Purpose: The purpose of this study was to evaluate the prevalence and the underreporting rate of sacroiliitis (SI) in a large cohort of patients with biopsy-proved Crohn’s disease (CD) who underwent magnetic resonance enterography (MRE) or computed tomography enterography (CTE). Materials and Methods: Patients with CD were recruited from eight Italian health centers in the period from January 2013 to December 2017. Disease activity was recorded according to the CD activity index (CDAI). The scans were read by two blinded readers who defined the presence of SI according to Assessment of SpondyloArthritis International Society (ASAS) classifications and European League Against Rheumatism (EULAR) recommendations. Moreover, SI was scored using a simplified Spondyloarthritis Research Consortium of Canada (SPARCC) scoring system. Results: Interobserver agreement in diagnosing SI on imaging was good (K = 0.72–0.83). SI was diagnosed in 129 (14.4%, 54 men, 75 women) out of 894 patients; however, sacroiliac joint (SIJ) abnormalities were not mentioned in the radiological reports of 112 patients (86%). Fifty (38.7%) out of 129 patients also underwent a subsequent SIJ evaluation through a dedicated MRI protocol to confirm SI. SI was found in a higher percentage of patients with “active” than “inactive” CD (18% vs. 4%). Conclusion: This study confirms the feasibility of CTE and MRE for the screening of SI in CD patients; however, it also underlines the remarkable problem concerning the underreporting of this entity in radiological practice.

Gastrointestinal Ultrasound (GIUS) in Intestinal Emergencies - An EFSUMB Position Paper

An interdisciplinary group of European experts summarizes the value of gastrointestinal ultrasound (GIUS) in the management of three time-critical causes of acute abdomen: bowel obstruction, gastrointestinal perforation and acute ischemic bowel disease. Based on an extensive literature review, statements for a targeted diagnostic strategy in these intestinal emergencies are presented. GIUS is best established in case of small bowel obstruction. Metanalyses and prospective studies showed a sensitivity and specificity comparable to that of computed tomography (CT) and superior to plain X-ray. GIUS may save time and radiation exposure and has the advantage of displaying bowel function directly. Gastrointestinal perforation is more challenging for less experienced investigators. Although GIUS in experienced hands has a relatively high sensitivity to establish a correct diagnosis, CT is the most sensitive method in this situation. The spectrum of intestinal ischemia ranges from self-limited ischemic colitis to fatal intestinal infarction. In acute arterial mesenteric ischemia, GIUS may provide information, but prompt CT angiography is the gold standard. On the other end of the spectrum, ischemic colitis shows typical ultrasound features that allow correct diagnosis. GIUS here has a diagnostic performance similar to CT and helps to differentiate mild from severe ischemic colitis.

Diagnostic and interventional radiology: an update

NOT PRESENT.

Computed tomography versus lower endoscopy as initial diagnostic method for evaluating patients with hematochezia at emergency room

For acute lower gastrointestinal bleeding (LGIB), lower gastrointestinal endoscopy is the preferred initial diagnostic test. However, it is difficult to perform urgently. Computed tomography (CT) is a convenient alternative.This study aimed to determine the diagnostic performance of CT compared to lower endoscopy as an initial test for evaluating acute LGIB.The medical records of 382 patients who visited our emergency department with hematochezia between January 2012 and January 2017 were retrospectively analyzed. Of them, 112 underwent CT, 65 underwent colonoscopy, and 205 underwent sigmoidoscopy as an initial test. For each method, sensitivity, specificity, positive predictive value, and negative predictive value were calculated upon active bleeding site detection and LGIB etiology diagnosis.The sensitivity, specificity, positive predictive value, and negative predictive value of CT for active bleeding site detection were 85.7%, 100%, 100%, and 96.9%, respectively, while those for identifying the etiology of LGIB were 87.4%, 40.0%, 83.5, and 47.6%, respectively.CT was not inferior to lower endoscopy for active bleeding site detection. Early localization and the exclusion of active bleeding were possible with CT. Etiology was diagnosed with high sensitivity and PPV by CT. Thus, CT can be an alternative initial diagnostic tool for evaluating acute LGIB.

Association of decreased variation of coefficient R-R interval with ischemic colitis and small bowel obstruction

Background

The parasympathetic nervous system exerts and controls intestinal tone. Several studies have suggested that the coefficient of the R–R intervals (CVRR) is useful for evaluating the parasympathetic nervous system.

Objectives

This study aimed to evaluate the relationship between gastrointestinal emergencies, specifically ischemic colitis (IC) and small bowel obstruction (SBO), and the autonomic nervous system.

Methods

In this retrospective study, a total of 13 patients with IC or SBO aged ≧65 years were analyzed. CVRR was measured in patients with IC and SBO and controls.

Results

CVRR averaged to 8.8% ± 2.5% in controls, 1.4% ± 0.4% in patients with IC, and 2.4% ± 1.0% in SBO groups (p < 0.001). CVRR was significantly lower in patients with IC and SBO than that in controls.

Conclusion

The results of this study demonstrate the possibility that CVRR may serve as a clinical index for assessing the functioning of the parasympathetic nervous system in patients with IC or SBO.

Clostridium difficile colitis: CT findings and differential diagnosis

Clostridium difficile infection (CDI) is a severe and potentially deadly infectious colitis whose incidence is dramatically increasing in the last decades, with more virulent strains. CDI should be suspected in case of unexplained diarrhea and abdominal pain in patients with a recent history of antibiotic use and healthcare exposures; diagnosis is based on a combination of clinical and laboratory findings with demonstration of C. difficile toxins by stool test. The advantages of contrast-enhanced computed tomography (CECT) are the noninvasiveness and the ability to evaluate both the colonic wall and the adjacent soft tissues. Considerable overlap exists between the CECT findings of CDI and those of colitis of other origins, such as typhlitis, ischemic colitis, graft-versus-host disease, radiation colitis and inflammatory bowel diseases; however, some features may help distinguish between these conditions. This paper provides a comprehensive overview of the imaging features of Clostridium difficile colitis and its mimics, with a view to assist the radiologist in reaching the correct diagnosis.

Magnetic resonance enterography (MRE) and ultrasonography (US) in the study of the small bowel in Crohn's disease: state of the art and review of the literature

Crohn’s disease (CD) is a chronic idiopathic disease and its diagnosis is based on a combination of clinical symptoms, laboratory tests and imaging data. There isn’t a diagnostic gold standard: the ileocolonoscopy with mucosal biopsies represents the standard for luminal disease, while cross-sectional imaging such as Ultrasound (US), Computed Tomography (CT) or Magnetic Resonance Imaging (MRI) can show transmural alterations and extraintestinal manifestations. CD is usually diagnosed in the young age and after baseline diagnosis, the patients have to undergo to variable follow-up depending on remission or active disease. The aim of our review is to compare Magnetic Resonance Enterography (MRE) to Ultrasonography (US) in the follow-up of CD. (www.actabiomedica.it)

Preoperative assessment of simple and complex anorectal fistulas: Tridimensional endoanal ultrasound? Magnetic resonance? Both?

PURPOSE

The purpose of the study is to evaluate the diagnostic value of tridimensional endoanal ultrasound (3D-EAUS) and magnetic resonance (MR) in the preoperative assessment of both simple and complex anorectal fistulas.

METHODS

All the patients referred for the treatment of anal fistulas were enrolled in this study and underwent, as preoperative assessment, anamnestic evaluation, clinical examination, and unenhanced and H2O2-enhanced 3D-EAUS and MR. The results of imaging evaluation were compared with surgical findings, considered as reference standard.

RESULTS

During the study period, 124 patients operated on for anal fistulas underwent complete preoperative imaging assessment. Perfect agreement between 3D-EAUS and surgery in the anal fistulas' severity grading was found (K = 1). The fistulas were classified as simple in 68/126 (53.9%) and complex in 58/126 (46.03%) cases, according to fistulas' Parks' classification and the most recent American Guidelines. In both simple and complex anal fistulas, 3D-EAUS did not show a significantly higher accuracy in the evaluation of internal openings, if compared with MR (P = 0.47; McNemar's Chi-square test). In the complex anal fistulas, MR showed a significantly higher accuracy in the evaluation of secondary extensions if compared with 3D-EAUS (P = 0.041; McNemar's Chi-square test), whereas in the simple anal fistulas, no significant difference was found.

CONCLUSION

In the preoperative work-up of patients with anorectal fistulas, 3D-EAUS may represent the first-line diagnostic tool. In cases of fistulas classified as complex by 3D-EAUS, MR may be indicated as adjunctive diagnostic imaging examination, to more carefully describe the fistulas' complete anatomy.

MDCT in acute ischaemic left colitis: a pictorial essay

The pathogenesis of acute ischaemic colitis depends on two different forms of vascular colonic insult: occlusive injury and non-occlusive injury. Clinically, ischaemic colitis may be classified as two major forms: mild (non-gangrenous) and acute fulminant (gangrenous). The classic presentation is abdominal pain, diarrhoea and/or rectal bleeding, but it is not specific and highly variable and so the diagnosis usually depends on clinical suspicion and is supported by serologic and colonoscopic findings. Imaging methods have their role in diagnosing IC. While plain radiography and ultrasound can orient the diagnosis, CT allows to define the morphofunctional alterations discriminating the non-occlusive forms from the occlusive forms and in most cases to estimate the timing of ischaemic damage. Purpose of the review is to define the role of CT in the early identification of pathological findings and in the definition of evolution of colonic ischaemic lesions, in order to plan the correct therapeutic approach, suggesting the decision of medical or surgical treatment.

Acute mesenteric ischemia: guidelines of the World Society of Emergency Surgery: a brief radiological commentary

The aim of this letter is to report some deeper explanations regarding the role of imaging in acute mesenteric ischemia.

The correlation between some computed tomography findings and the cause of ischemia as well as other main factors that could condition the computed tomography appearance of this critical issue is also discussed.

Ischaemic colitis: uncertainty in diagnosis, pathophysiology and management

Ischaemic colitis is the most common form of gastrointestinal ischaemia, but may be confused with acute mesenteric ischaemia, inflammatory bowel disease or infectious colitis. This review article outlines the current classification, epidemiology and risk factors, as well as approaches about diagnosis and management to guide clinical practice. It also identifies areas for further research.

Advents in the Diagnosis and Management of Ischemic Colitis

BACKGROUND

Ischemic colitis (IC) is a common type of ischemic insult, resulting from decreased arterial blood flow to the colon. This disease can be caused from either atherosclerotic occlusive vascular disease or non-occlusive disease. The aim of this study is to present the diagnostic methodology and management of this severe disease based on current literature.

METHODS

A literature search has been done including articles referring to modern diagnosis and management of IC.

RESULTS

IC is usually a transient disease, but it can also cause gangrene of the colon, requiring emergency surgical exploration. Diagnosis is troublesome and is based on imaging examinations, mainly computerized tomography, which in association with colonoscopy can delineate the distribution pattern and severity of disease.

CONCLUSION

The majority of patients with mild disease have usually complete clinical recovery within a short period. The severe forms of the disease carry high morbidity and mortality rates and prompt surgical intervention is the only way to improve the associated severe prognosis.

Diagnostic value of arterial blood gas lactate concentration in the different forms of mesenteric ischemia

PURPOSE

The role of serum lactate measurement in patients with intestinal ischemia still remains unclear. The aim of this study was to prospectively evaluate the diagnostic performance of arterial blood gas lactate concentrations in the patients with acute mesenteric ischemia and its different forms.

METHODS

All the patients reporting abdominal pain associated with risk factors for mesenteric ischemia underwent arterial blood gas and contrast enhanced abdominal computer tomography (CT).

RESULTS

At CT, 201 patients (70.7%) showed a nonischemic disease (group 1) and 83 patients (29.2%) showed findings of mesenteric ischemia. Out of these, 35 patients (42.1%) showed bowel ischemia secondary to non vascular causes (group 2) and 48 (57.8%) had a vascular intestinal ischemia (group 3). Out of these, 20 showed small bowel arterial occlusion (group 3a), 13 a small bowel nonocclusive ischemia (group 3b), 7 a venous small bowel occlusion (group 3c) and 8 showed isolated colonic ischemia (group 3d). The median lactate serum level was significantly higher in patients with vascular ischemia if compared with patients with nonischemic disease and secondary mesenteric ischemia (p < 0.0001; Kruskal-Wallis test). The areas under ROC curves for the lactate serum levels in the groups 2, 3, 3a, 3b, 3c and 3d were, respectively, 0.61, 0.85, 0.93, 0.93, 0.68 and 0.67.

CONCLUSIONS

Arterial blood gas lactate levels seem to show good diagnostic accuracy in diagnosing small bowel arterial and nonocclusive ischemia and poor accuracy in diagnosing secondary mesenteric ischemia, small bowel venous ischemia and ischemic colitis.

Ischemic Colitis Diagnosed by Magnetic Resonance Imaging during Lenalidomide Treatment in a Patient with Relapsed Multiple Myeloma

Introduction

Multiple myeloma is the second most common hematological neoplasm that also affects young patients. The progression-free survival after autologous stem cell transplant has improved with the introduction of several novel agents such as lenalidomide, which may, however, increase the risk of adverse events.

Methods

We describe the case of a 54-year-old woman with relapse of multiple myeloma 3 years after myeloablative allogeneic stem cell transplant who developed abdominal pain and bloody diarrhea following 7 months of lenalidomide therapy.

Results

Abdominal plain x-ray and magnetic resonance imaging (MRI) without intravenous contrast material showed left-sided and splenic flexure acute ischemic colitis with reperfusion phenomena. Continuous intravenous infusion of unfractionated heparin was given with metronidazole and meropenem and the patient improved within a few days. MRI performed 15 days later confirmed complete recovery of ischemic colitis.

Conclusions

To our knowledge there have been no previously reported cases of ischemic colitis during lenalidomide therapy as a single agent in relapsed or refractory multiple myeloma, in particular promptly diagnosed by MRI.

Ischemic Colitis Diagnosed by Magnetic Resonance Imaging during Lenalidomide Treatment in a Patient with Relapsed Multiple Myeloma

Introduction

Multiple myeloma is the second most common hematological neoplasm that also affects young patients. The progression-free survival after autologous stem cell transplant has improved with the introduction of several novel agents such as lenalidomide, which may, however, increase the risk of adverse events.

Methods

We describe the case of a 54-year-old woman with relapse of multiple myeloma 3 years after myeloablative allogeneic stem cell transplant who developed abdominal pain and bloody diarrhea following 7 months of lenalidomide therapy.

Results

Abdominal plain x-ray and magnetic resonance imaging (MRI) without intravenous contrast material showed left-sided and splenic flexure acute ischemic colitis with reperfusion phenomena. Continuous intravenous infusion of unfractionated heparin was given with metronidazole and meropenem and the patient improved within a few days. MRI performed 15 days later confirmed complete recovery of ischemic colitis.

Conclusions

To our knowledge there have been no previously reported cases of ischemic colitis during lenalidomide therapy as a single agent in relapsed or refractory multiple myeloma, in particular promptly diagnosed by MRI.

Diagnosis and treatment of ischemic colitis

Ischemic colitis (IC) is a common reason of acute lower gastrointestinal bleeding, and it is frequently seen in elderly people. In recent years, both the incidence and prevalence of IC have been rising. Most episodes of IC are transient and self-limited and only a minority of cases are severe. IC often has missed and delayed diagnosis. This review mainly focuses on the progress in the understanding of the diagnosis and therapy of IC.

Colorectal cancer mimics: a review of the usual suspects with pathology correlation

Colorectal cancer is the third most commonly diagnosed cancer in men and second most commonly diagnosed cancer in women worldwide. Initial diagnosis of colorectal malignancy is generally made on colonoscopy, sigmoidoscopy or digital rectal examination; however, with increased use of CT as primary investigation in patients with lower gastrointestinal symptoms, the diagnosis of colon cancer is often first apparent to a radiologist prior to more invasive tests. CT can demonstrate a discrete soft-tissue mass that narrows the colonic lumen or focal nodular wall thickening/stricture and a variety of pericolonic changes. Pattern of wall thickening has been described as an aid to differential diagnosis; however, significant overlap remains between primary colonic tumor and non-colonic tumors or benign conditions. Imaging is non-specific, and appropriate clinical history, direct inspection, histological analysis, and sometimes discussion at MDT are essential for accurate diagnosis and treatment planning. In this article, we will review the imaging features of some of these benign and malignant mimics of colorectal cancer, with accompanying histology slides where appropriate.

Anatomic and radiologic review of chronic mesenteric ischemia and its treatment

Chronic mesenteric ischemia (CMI) is a vascular occlusive disease process that generally affects the elderly population. Clinical presentation occurs when two of the three mesenteric arteries are affected and includes non-specific abdominal pain and weight loss. The most common cause of CMI is atherosclerotic arterial occlusion. The aim of this review is to present the vascular anatomy of the mesenteric arterial circulation including the different collateral pathways. The imaging findings and the different treatment options with a brief review of the literature is presented.

MDCT in ischaemic colitis: how to define the aetiology and acute, subacute and chronic phase of damage in the emergency setting

Ischemic colitis (IC) is the most common vascular disorder of the gastrointestinal tract with a reported incidence of 6.1-44 cases/100,000 person years with confirmatory histopathology. However, the true incidence of IC poses some difficulty, and even vigilant clinicians with patients at high risk often miss the diagnosis, since clinical presentation is non-specific or could have a mild transient nature. Detection of IC results is crucial to plan the correct therapeutic approach and reduce the reported mortality rate (4-12%). Diagnosis of IC is based on a combination of clinical suspicion, radiological, endoscopic and histological findings. Some consider colonoscopy as a diagnostic test of choice; however, preparation is required and it is not without risk, above all in patients who are severely ill. There are two manifestations of vascular colonic insult: ischaemic and reperfusive. The first one occurs above all during ischaemic/non-occlusive mesenteric ischaemia; in this case, the colonic wall appears thinned with dilated lumen and fluid appears in the paracolic space. When reperfusion occurs, the large bowel wall appears thickened and stratified, because of subepithelial oedema and/or haemorrhage, with consequent lumen calibre reduction. Shaggy contour of the involved intestine and misty mesentery are associated with the pericolic fluid. The pericolic fluid results are a crucial finding for IC diagnosis since its evidence suggests the presence of an ongoing damage thus focusing the attention on other pathological aspects which could be otherwise misdiagnosed, such as thinned or thickened colonic wall. Moreover, the pericolic fluid may increase or decrease, depending on the evolution of the ischaemic damage, suggesting the decision of medical or surgical treatment. Radiologists should not forget the hypothesis of IC, being aware that multidetector CT could be sufficient to suggest the diagnosis of IC, allowing for early identification and grading definition, and in a short-term follow-up, discriminating patients who need urgent surgery from patients in whom medical treatment and follow-up can be proposed.

Update on Colon Ischemia: Recent Insights and Advances

Colon ischemia (CI) is the most common manifestation of ischemic injury to the gastrointestinal (GI) tract. This usually self-limited disease is being diagnosed more frequently, and the list of known causes is increasing. Local hypoperfusion and reperfusion injury are both thought to contribute to the disease process, which manifests with a wide spectrum of injury including reversible colopathy (subepithelial hemorrhage and edema), transient colitis, chronic colitis, stricture, gangrene, and fulminant universal colitis. The distribution is usually segmental with left-sided disease (e.g., inferior mesenteric artery distribution) being more frequently observed than right-sided involvement (e.g., superior mesenteric artery distribution). Any portion of the colon can be affected, but the anatomic distribution of CI recently has been shown to be associated with outcome. Patients with isolated-right colon ischemia (IRCI) have a different presentation and worse outcomes than other distributions of disease. Although somewhat variable depending on disease location, CI presents with cramping abdominal pains over the segment of colon involved followed by a short course of bloody diarrhea. Diagnosis is usually made clinically and is supported with serologic, radiologic, and colonoscopic findings. Colonoscopy is the most accurate diagnostic study. Most patients respond to conservative supportive therapy although some with more severe disease require antimicrobials and/or surgical intervention.

Features and Outcomes of Patients With Ischemia Isolated to the Right Side of the Colon When Accompanied or Followed by Acute Mesenteric Ischemia

BACKGROUND & AIMS

Patients with ischemia isolated to the right side of the colon (IRCI) frequently have poor outcomes. IRCI and acute mesenteric ischemia (AMI) are caused by reductions in blood supply from the superior mesenteric artery and its branches. We investigated a group of patients with IRCI associated with AMI that developed initially or shortly thereafter, and compared outcomes of patients with IRCI and AMI vs those with only IRCI.

METHODS

We performed a retrospective study of data collected from 313 consecutive patients with colonic ischemia who were hospitalized at Montefiore Medical Center in New York from 1998 through 2009. Based on colonoscopy, biopsy analyses, and surgery reports, we identified patients with IRCI with concurrent or proximately developing AMI (IRCI+AMI) and those with only IRCI. Demographics, evaluation, disease distribution, and outcome data were compared between groups.

RESULTS

Of 313 patients with colonic ischemia, 20.8% had IRCI; of these, 84.6% had only IRCI and 15.4% had IRCI+AMI. Chronic obstructive pulmonary disease was found more frequently in patients with IRCI+AMI (40.0%) than in patients with IRCI alone (12.7%; P < .05). At the time of IRCI diagnosis, mean levels of blood urea nitrogen were significantly higher in patients with IRCI+AMI than with IRCI alone (37.9 ± 14.4 mEq/L vs 26.4 ± 18.8 mEq/L; P < .05), as were mean white blood cell counts (20.3 ± 12.1 vs 12.7 ± 6.8 × 10(3)/μL; P < .01). A higher proportion of patients with IRCI+AMI underwent surgery than patients with only IRCI (100.0% vs 43.1%; P = .001), and 30-day mortality was higher among patients with IRCI+AMI (70.0% vs 14.5% for patients with only IRCI; P < .001).

CONCLUSIONS

Based on an analysis of 313 patients with colonic ischemia, patients with IRCI+AMI have even more severe disease than those with IRCI alone. Chronic obstructive pulmonary disease was observed more frequently in patients with IRCI+AMI. Patients with IRCI+AMI had increased levels of blood urea nitrogen and/or white blood cell counts. Patients with IRCI should undergo vascular imaging analyses immediately to detect AMI; patients without AMI should be monitored closely for its subsequent development.

Protective effect of melatonin-supported adipose-derived mesenchymal stem cells against small bowel ischemia-reperfusion injury in rat

We tested the hypothesis that combined melatonin and autologous adipose-derived mesenchymal stem cells (ADMSC) was superior to either alone against small bowel ischemia-reperfusion (SBIR) injury induced by superior mesenteric artery clamping for 30 min followed by reperfusion for 72 hr. Male adult Sprague Dawley rats (n = 50) were equally categorized into sham-operated controls SC, SBIR, SBIR-ADMSC (1.0 × 10(6) intravenous and 1.0 × 10(6) intrajejunal injection), SBIR-melatonin (intraperitoneal 20 mg/kg at 30 min after SI ischemia and 50 mg/kg at 6 and 18 hr after SI reperfusion), and SBIR-ADMSC-melatonin groups. The results demonstrated that the circulating levels of TNF-α, MPO, LyG6+ cells, CD68+ cells, WBC count, and gut permeability were highest in SBIR and lowest in SC, significantly higher in SBIR-ADMSC group and further increased in SBIR-melatonin group than in the combined therapy group (all P < 0.001). The ischemic mucosal damage score, the protein expressions of inflammation (TNF-α, NF-κB, MMP-9, MPO, and iNOS), oxidative stress (NOX-1, NOX-2, and oxidized protein), apoptosis (APAF-1, mitochondrial Bax, cleaved caspase-3 and PARP), mitochondrial damage (cytosolic cytochrome C) and DNA damage (γ-H2AX) markers, as well as cellular expressions of proliferation (PCNA), apoptosis (caspase-3, TUNEL assay), and DNA damage (γ-H2AX) showed an identical pattern, whereas mitochondrial cytochrome C exhibited an opposite pattern compared to that of inflammation among all groups (all P < 0.001). Besides, antioxidant expressions at protein (NQO-1, GR, and GPx) and cellular (HO-1) levels progressively increased from SC to the combined treatment group (all P < 0.001). In conclusion, combined melatonin-ADMSC treatment offered additive beneficial effect against SBIR injury.

Differential Diagnosis of Colonic Strictures: Pictorial Review with Illustrations from Computed Tomography Colonography

Strictures of the colon can lead to significant morbidity requiring surgical management. The etiology of strictures is broad and generally categorized as benign, malignant, or pseudostrictures. Computed tomography (CT) is a crucial imaging modality in the assessment and characterization of colonic pathologies but colonoscopy remains the diagnostic gold standard. However, in the setting of incomplete colonoscopy due to strictures, the imaging features of CT will be relied on. This review will focus on the CT features of different colon pathologies leading to strictures and will be illustrated with images from 10 years of experience with CT colonography at our institutions from 2002-2012 (Hotel Dieu Hospital, Queen's University and Mount Sinai Hospital, University of Toronto).