Multi-detector CT features of acute intestinal ischemia and their prognostic correlations

The role of dual-energy computed tomography (DECT) in emergency radiology: a visual guide to advanced diagnostics

Dual-energy computed tomography (DECT) has become an essential tool in emergency radiology, significantly enhancing diagnostic capabilities for a variety of acute conditions. By utilising two distinct X-ray energy spectra, DECT differentiates materials based on their attenuation properties, providing detailed insights into tissue composition and pathology. In emergency settings, DECT is used in thoracic imaging for the detection of pulmonary embolism, in abdominal imaging to enhance the diagnosis and characterisation of conditions such as pancreatitis, appendicitis, gastrointestinal bleeding, and bowel ischaemia and in the genitourinary system for identifying kidney stones, pyelonephritis, and urinary bleeding. In neuroimaging, DECT enables image optimisation through virtual monochromatic images and the reduction of metal artifacts. It helps in the differential diagnosis of haemorrhage versus tumour-related haemorrhage, haemorrhage versus contrast extravasation, and in the dating of vertebral collapse. DECT offers several advantages, including enhanced visualisation, the potential to reduce radiation exposure and contrast medium, and improved diagnostic accuracy across a wide range of conditions. However, its routine clinical adoption is still evolving due to challenges such as limited availability, cost, and the need for specialised training. This pictorial essay aims to encourage the broader integration of DECT into emergency imaging protocols by showcasing its clinical applications and benefits.

Radiological predictive factors of transmural intestinal necrosis in acute mesenteric ischemia: systematic review and meta-analysis

OBJECTIVE

Transmural intestinal necrosis (TIN) is related to high mortality in patients with acute mesenteric ischemia (AMI). Radiological predictive factors of TIN in AMI remains controversial. This study aimed to identify the CT-based predictive factors of TIN in AMI.

METHODS

EMBASE and PUBMED were searched for publications predicting TIN using radiological features. Quality Assessment of Diagnostic Accuracy Studies-2 was used to assess the methodological quality of individual studies. Data were presented in terms of diagnostic odds ratio (DOR), sensitivity, specificity, and 95% confidence interval (CI). The random-effects models were used for the meta-analysis.

RESULTS

Eleven studies including 1037 cases with AMI were considered. The meta-analysis showed that bowel wall thinning (DOR = 13.10; 95% CI: 3.71, 46.25), decreased or absent bowel wall enhancement (DOR = 5.77; 95% CI: 2.95, 11.30), bowel dilation (DOR = 3.23; 95% CI: 2.03, 5.15), pneumatosis intestinalis (DOR = 5.78; 95% CI: 2.24, 14.95), porto-mesenteric venous gas (DOR = 5.36; 95% CI: 2.14, 13.40), and arterial occlusive AMI (DOR = 2.66; 95% CI: 1.53, 4.63) were risk factors for predicting TIN. Bowel wall thinning and porto-mesenteric venous gas displayed high specificity to diagnose TIN (98%, 95%, respectively). The subgroup analysis showed that decreased or absent bowel wall enhancement (DOR = 8.23; 95% CI: 4.67, 14.51) and bowel dilation (DOR = 3.14; 95% CI: 1.55, 6.39) were predictors of TIN in venous occlusive AMI, which were not related to TIN in arterial-origin AMI.

CONCLUSIONS

For predicting TIN, there are specific radiological features. The radiological predictors of TIN may differ according to the various causes of AMI. Future primary studies should further evaluate the relationships between radiological signs and TIN based on different etiologies.

KEY POINTS

• Bowel wall thinning, decreased or absent bowel wall enhancement, bowel dilation, pneumatosis intestinalis, porto-mesenteric venous gas, and arterial occlusive AMI were risk factors for predicting TIN. • Decreased or absent bowel wall enhancement and bowel dilation were predictors of TIN in venous occlusive AMI, which were not related to TIN in arterial-origin AMI.

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.

Artificial Intelligence in Emergency Radiology: Where Are We Going?

Emergency Radiology is a unique branch of imaging, as rapidity in the diagnosis and management of different pathologies is essential to saving patients' lives. Artificial Intelligence (AI) has many potential applications in emergency radiology: firstly, image acquisition can be facilitated by reducing acquisition times through automatic positioning and minimizing artifacts with AI-based reconstruction systems to optimize image quality, even in critical patients; secondly, it enables an efficient workflow (AI algorithms integrated with RIS-PACS workflow), by analyzing the characteristics and images of patients, detecting high-priority examinations and patients with emergent critical findings. Different machine and deep learning algorithms have been trained for the automated detection of different types of emergency disorders (e.g., intracranial hemorrhage, bone fractures, pneumonia), to help radiologists to detect relevant findings. AI-based smart reporting, summarizing patients' clinical data, and analyzing the grading of the imaging abnormalities, can provide an objective indicator of the disease's severity, resulting in quick and optimized treatment planning. In this review, we provide an overview of the different AI tools available in emergency radiology, to keep radiologists up to date on the current technological evolution in this field.

Development of a Novel Scoring Model to Estimate the Severity Grade of Mesenteric Artery Stenosis

Objective: This study aimed to derive a new scoring model from estimating the severity grade of mesenteric artery stenosis. We sought to analyze the relationship between the new scoring model and the development, treatment, and mortality of chronic mesenteric ischemia (CMI). Methods: This retrospective study included 242 patients (128 (53%) women and 114 (47%) men) with suspected CMI from January 2011 to December 2020. A weighted sum six-point score (CSI-score; the celiac artery is abbreviated by “C”, superior mesenteric artery by “S”, and inferior mesenteric artery by “I”) based on the number of affected vessels and the extent and grade of the stenosis or occlusion of the involved visceral arteries was derived by maximizing the area under the ROC curve. The calculated CSI-score ranged from 0 to 22. The patients were divided according to the best cut-off point into low-score (CSI-score < 8) and high-score (CSI-score ≥ 8) groups. Results: The area under the receiver operating characteristic curve (AUC) of the CSI-score was 0.86 (95% CI, 0.82−0.91). The best cut-off point of “8” represented the highest value of Youden’s index (0.58) with a sensitivity of 87% and specificity of 72%. The cohort was divided according to the cut-off point into a low-score group (n = 100 patients, 41%) and high-score group (n = 142 patients, 59%) and according to the clinical presentation into a CMI group (n = 109 patients, 45%) and non-CMI group (n = 133 patients, 55%). The median CSI-score for all patients was 10 (range: 0 -22). High-scoring patients showed statistically significant higher rates of coronary artery disease (54% vs. 36%, p = 0.007), chronic renal insufficiency (50% vs. 30%, p = 0.002), and peripheral arterial disease (57% vs. 16%, p < 0.001). A total of 109 (45%) patients underwent invasive treatment of the visceral arteries and were more often in the high-score group (69% vs. 11%, p < 0.001). Of those, 79 (72%) patients underwent primary endovascular treatment, and 44 (40%) patients underwent primary open surgery or open conversion after endovascular treatment. Sixteen (7%) patients died during the follow-up, with a statistically significant difference between high- and low-scoring patients (9% vs. 0%, p = 0.008). The score stratification showed that the percentage of patients treated with endovascular and open surgical methods, the recurrence of the stenosis or failure of the endovascular treatment, the need for a bypass procedure, and the mortality rates significantly increased in the subgroups. The CSI-score demonstrated an excellent ability to discriminate between patients who needed treatment and those who did not, with an AUC of 0.87 (95% CI, 0.82−0.91). Additionally, the CSI-score’s ability to predict the patients’ mortality was moderate, with an AUC of 0.73 (95% CI, 0.62−0.83). Conclusions: The new scoring model can estimate the severity grade of the stenosis of the mesenteric arteries. Our study showed a strong association of the score with the presence of chronic mesenteric ischemia, the need for treatment, the need for open surgery, and mortality.

Portal vein gas combined with pneumatosis intestinalis and emphysematous cystitis: A case report and literature review

BACKGROUND

Portal venous gas (PVG) is a rare clinical condition usually indicative of severe disorders, including necrotizing enterocolitis, bowel ischemia, or bowel wall rupture/infarction. Pneumatosis intestinalis (PI) is a rare illness characterized by an infiltration of gas into the intestinal wall. Emphysematous cystitis (EC) is relatively rare and characterized by intramural and/or intraluminal bladder gas best depicted by cross-sectional imaging. Our study reports a rare case coexistence of PVG presenting with PI and EC.

CASE SUMMARY

An 86-year-old woman was admitted to the emergency room due to the progressive aggravation of pain because of abdominal fullness and distention, complicated with vomiting and stopping defecation for 4 d. The abdominal computed tomography (CT) plain scan indicated intestinal obstruction with ischemia changes, gas in the portal vein, left renal artery, superior mesenteric artery, superior mesenteric vein, some branch vessels, and bladder pneumatosis with air-fluid levels. Emergency surgery was conducted on the patient. Ischemic necrosis was found in the small intestine approximately 110 cm below the Treitz ligament and in the ileocecal junction and ascending colon canals. This included excision of the necrotic small intestine and right colon, fistulation of the proximal small intestine, and distal closure of the transverse colon. Subsequently, the patient displayed postoperative short bowel syndrome but had a good recovery. She received intravenous fluid infusion and enteral nutrition maintenance every other day after discharge from the community hospital.

CONCLUSION

Emergency surgery should be performed when CT shows signs of PVG with PI and EC along with a clinical situation strongly suggestive of bowel ischemia.

Prognostic factors for the successful conservative management of nonocclusive mesenteric ischemia

Background

The criteria for deciding upon non-operative management for nonocclusive mesenteric ischemia (NOMI) are poorly defined. The aim of this study is to determine the prognostic factors for survival in conservative treatment of NOMI.

Methods

Patients with bowel ischemia were identified by searching for “ICD-10 code K550” in the Diagnosis Procedure Combination database between June 2015 and May 2020. A total of 457 patients were extracted and their medical records, including the clinical factors, imaging findings and outcomes, were analyzed retrospectively. Diagnosis of NOMI was confirmed by the presence of specific findings in contrast-enhanced multidetector-row CT. Twenty-six patients with conservative therapy for NOMI, including four cases of explorative laparotomy or laparoscopy, were enrolled.

Results

Among the 26 cases without surgical intervention, eight patients (31%) survived to discharge. The level of albumin was significantly higher, and the levels of lactate dehydrogenase, total bilirubin, C-reactive protein, and lactate were significantly lower in the survivors than the non-survivors. Sepsis-related Organ Failure Assessment (SOFA) score was significantly lower in the survivors than the non-survivors. The most reliable predictor of survival for NOMI was SOFA score (cutoff value ≤ 3 points), which had the highest AUC value (0.899) with odds ratio of 0.075 (CI: 0.0096–0.58).

Conclusions

The SOFA score and several biological markers are promising predictors to determine a treatment plan for NOMI and to avoid unnecessary laparotomy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13017-022-00436-w.

Comprehensive review of acute small bowel ischemia: CT imaging findings, pearls, and pitfalls

Acute small bowel ischemia is a life-threatening condition with a high mortality rate due to its lack of specific symptoms and laboratory profile, which render difficulty in establishing early diagnosis. The etiology of acute small bowel ischemia includes occlusive forms (arterial embolism, arterial thrombosis, and venous thrombosis) and nonocclusive mesenteric ischemia, of which arterial causes are far more common than venous causes. CT, the mainstay of accurate diagnoses, allows the identification of the features of vascular abnormalities and intestinal ischemic injuries, and helps clinicians to restore intestinal blood flow. Without treatment, the prognosis for acute small bowel ischemia is poor. A high index of suspicion and familiarity with the CT spectral findings of bowel ischemia are required to ensure rapid recognition of this condition.

Isolated duodenal ischemia of unknown etiology: a case report

Background

Acute abdomen is among the most common presentations observed in clinical practice. The present study describes a patient with isolated duodenal ischemia as an extremely rare etiology of acute abdomen.

Case presentation

A 79-year-old male with acute abdominal pain, nausea, and vomiting presented to the emergency department of our hospital. He was diagnosed with myelodysplastic syndrome 7 years ago, for which he took thalidomide and erythropoietin as the main medications. The prominent findings of the physical examination were hypotension, tachycardia, fever, mild hypoxemia, and epigastric and right upper quadrant tenderness of the abdomen. Except for mildly increased creatinine and lipase, other laboratory findings were in concordance with myelodysplastic syndrome. Due to the patient’s oliguria, the computed tomography (CT) scan was performed without contrast, which, together with the ultrasonography, raised the clinical impression of acute pancreatitis. The patient’s hypotension was refractive to supportive treatment, resulting in progressive deterioration of the clinical condition. A later contrast-enhanced CT scan suggested microvascular ischemia of the duodenum. An emergent Whipple’s procedure was planned initially, which was later switched to a damage control surgery due to the patient’s cardiac arrest during the surgery. Despite all the supportive therapy provided at the intensive care unit, the patient expired of a cardiac arrest which occurred two hours after the termination of the surgery.

Conclusions

The high rate of mortality in duodenal necrosis necessitates emergent diagnosis and proper management. When other common etiologies are ruled out, clinicians should consider duodenal pathology as a potential cause of acute abdomen.

Multidetector computed tomography: a corner stone imaging modality in evaluation of acute small bowel diseases

Background

The diagnosis of acute small bowel diseases is one of the challenging issues that confronted by the radiologists so accurate diagnosis is essential to determine the appropriate way of management. CT has become the preferred imaging tool to evaluate acute small bowel diseases. Our study aimed to assess the role of MDCT in evaluation of acute abdomen secondary to small bowel origin by identification and differentiation between different acute small bowel pathologies.

Results

Thirty-eight patients presented with acute abdomen of small bowel origin from June 2019 to September 2019. The mean age of incidence was 48 ± 19 years ranged from 4 to 88 years. Males represented by 23 patients (60.5%). Acute exacerbation of inflammatory bowel diseases (Crohn’s disease) represented by (34.2%), small bowel obstruction (31.6%), ischemic bowel diseases (21.1%), small bowel perforation (10.5%) and infectious (TB enteritis) small bowel disease (2.6%). MDCT had an overall high sensitivity (97.3%) in assessment of acute small bowel diseases in correlation with post-operative data and follow-up response to management.

Conclusions

MDCT is a reliable diagnostic imaging tool for assessment of patients with acute abdomen secondary to small bowel origin with high-efficiency in differentiation between different pathological entities that causing acute abdomen.

Diagnostic approach to small-bowel wall thickening: Beyond Crohn's disease and cancer

Although small-bowel wall thickening is a common manifestation of Crohn's disease and tumors, many other entities can give rise to similar imaging findings. The small bowel is difficult to access by endoscopy, so radiologic imaging tests play an essential role in the diagnosis of conditions involving the small bowel. The main objectives of this paper are to explain the definition of small-bowel wall thickening, analyze the patterns of involvement seen in multidetector computed tomography (MDCT) with intravenous contrast administration, and provide an image-based review of the different causes of small-bowel wall thickening. The differential diagnosis must include many entities because wall thickening can result from immune-mediated, infectious, or vascular causes, as well as from toxicity and other lesser-known entities. As the imaging appearance of many of these conditions overlap, clinical and laboratory findings are necessary to support the imaging diagnosis.

Diagnostic approach to small-bowel wall thickening: beyond Crohn's disease and cancer

Although small-bowel wall thickening is a common manifestation of Crohn's disease and tumors, many other entities can give rise to similar imaging findings. The small bowel is difficult to access by endoscopy, so radiologic imaging tests play an essential role in the diagnosis of conditions involving the small bowel. The main objectives of this paper are to explain the definition of small-bowel wall thickening, analyze the patterns of involvement seen in multidetector computed tomography (MDCT) with intravenous contrast administration, and provide an image-based review of the different causes of small-bowel wall thickening. The differential diagnosis must include many entities because wall thickening can result from immune-mediated, infectious, or vascular causes, as well as from toxicity and other lesser-known entities. As the imaging appearance of many of these conditions overlap, clinical and laboratory findings are necessary to support the imaging diagnosis.

Gastrointestinal Applications of Iodine Quantification Using Dual-Energy CT: A Systematic Review

Dual-energy computed tomography (DECT) can estimate tissue vascularity and perfusion via iodine quantification. The aim of this systematic review was to outline current and emerging clinical applications of iodine quantification within the gastrointestinal tract using DECT. The search was conducted with three databases: EMBASE, Pubmed and The Cochrane Library. This identified 449 studies after duplicate removal. From a total of 570 selected studies, 30 studies were enrolled for the systematic review. The studies were categorized into four main topics: gastric tumors (12 studies), colorectal tumors (8 studies), Crohn’s disease (4 studies) and miscellaneous applications (6 studies). Findings included a significant difference in iodine concentration (IC) measurements in perigastric fat between T1–3 vs. T4 stage gastric cancer, poorly and well differentiated gastric and colorectal cancer, responders vs. non-responders following chemo- or chemoradiotherapy treatment among cancer patients, and a positive correlation between IC and Crohn’s disease activity. In conclusion, iodine quantification with DECT may be used preoperatively in cancer imaging as well as for monitoring treatment response. Future studies are warranted to evaluate the capabilities and limitations of DECT in splanchnic flow.

Contrast-Enhanced CT for the Diagnosis of Acute Mesenteric Ischemia

OBJECTIVE. The purpose of this article is to provide an overview of the diagnostic and prognostic roles of CT in the management of acute mesenteric ischemia. CONCLUSION. Acute mesenteric ischemia is defined as inadequate blood supply to the gastrointestinal tract resulting in ischemic and inflammatory injury. The prognosis is poor without treatment. Contrast-enhanced CT has become the cornerstone of diagnosis to identify features of vascular disorders and of intestinal ischemic injury and to visualize bowel necrosis.

Combined hyperdense gallbladder wall-lumen sign: new computed tomography sign in acute gangrenous cholecystitis

Purpose

The objective of our study was to evaluate the combined hyperdense gallbladder wall-lumen sign on computed tomography (CT) in diagnosing gangrenous cholecystitis.

Material and methods

We retrospectively reviewed the unenhanced CT scans of surgically proven cases of acute gangrenous (GCh) and non-gangrenous cholecystitis (nonGCh). Eleven cases of pathologically proven acute gangrenous cholecystitis and 12 consecutive cases of surgically proven acute non-gangrenous cholecystitis that underwent CT at our institute were included in the study so as to have 1 : 1 control. The Hounsfield unit (HU) value of the gallbladder wall and intraluminal bile was measured. Interobserver variability for individual CT findings was also assessed.

Results

The gangrenous cholecystitis group had significantly higher HU values of wall and bile (median value of 33 HU vs. 21 HU and median value of 21 HU vs. 8.5 HU, respectively, p < 0.05). The area under the receiver operator characteristic curve for HU lumen was 0.80 (95% CI: 0.62-0.98, p = 0.014) with an ideal cut-off at 31.5 HU, where the sensitivity was 54.5% and specificity was 91.7%. HU lumen has an even better assessment for gangrenous cholecystitis with AUC of its ROC as 0.92 (95% CI: 0.80-1.00, p = 0.001) with an ideal cut-off at 12.5 HU, where the sensitivity was 81.8% and specificity was 91.7%. The combined wall-lumen cut-off is 35 HU with sensitivity of 100% and specificity of 75%.

Conclusion

A cut-off CT density value of the gallbladder wall of more than 31.5 HU, intraluminal bile more than 12.5 HU, and combined wall-lumen HU of more than 35 can predict GCh.

Review Article: Mesenteric Ischemia

PURPOSE OF REVIEW

Mesenteric ischemia (MI), both acute (AMI) and chronic (CMI), is a challenging diagnosis to make, and early diagnosis and treatment are vital to improve outcomes. This manuscript summarizes the most up to date information on diagnosis and treatment of these disorders.

RECENT FINDINGS

There have been several significant advancements in the computed tomography (CT) diagnostic imaging as well as medical and endovascular management of AMI and CMI. In appropriate populations, endovascular interventions appear superior to open surgical management with lower mortality, morbidity, and cost of care. Efficient clinical identification and targeted testing are essential to diagnose AMI and CMI. Aggressive resuscitation and early endovascular (or in select cases, surgical) intervention improve outcomes in those with AMI. In those with CMI, considering this on the differential diagnosis and imaging appropriately can identify those that might benefit from intervention and halt progression to acute episodes.

Split-bolus CTA for mesenteric ischemia with a single scan opacifying arterial and mesenteric venous systems

OBJECTIVE

To evaluate the diagnostic accuracy of split-bolus single-scan computed tomography angiography (CTA) protocol for evaluation of acute mesenteric ischemia and alternate diagnoses.

MATERIALS AND METHODS

In this IRB-approved, HIPAA-compliant retrospective study, consecutive patients from 21 October 2016 to 6 May 2018 evaluated for mesenteric ischemia with split-bolus CTA (a single scan in concurrent arterial and portal venous phase) in a single tertiary academic institution were included. Intravenous contrast was administered on weight-based basis. Quantitative and qualitative assessments of superior mesenteric artery (SMA) and superior mesenteric vein (SMV) attenuation and patency were performed by two independent reviewers. CT imaging findings were correlated with clinical reference outcomes.

RESULTS

One hundred fifty-four patients (age 66.3 ± 14.1 years, BMI 27.3 ± 6, 86 (56%) female) were included. CTA studies were performed with a volumetric CT dose index of 15.9 ± 5.5 mSv and dose length product of 1042.9 ± 389.4 mGy cm. Average intravenous contrast volume administered was 164.3 ± 12.1 cc. SMA attenuation was 263.6 ± 92.4HU, SMV was 190 ± 50.2HU. Qualitative assessment of SMA and SMV showed good opacification in all patients. 17/154 (11%) patients were diagnosed on CT with mesenteric ischemia; in 6/154 (4%), CTA studies were indeterminate; in 131/154 (85%), CTA confidently ruled out mesenteric ischemia. Alternate diagnoses were made in 38/154 (25%) patients. Using composite clinical outcomes as a reference standard, sensitivity of split-bolus CTA protocol for diagnosis of mesenteric ischemia is 100% (95% CI 79-100%), and specificity is 99% (95% CI 96-100%).

CONCLUSIONS

Split-bolus CTA has high sensitivity and specificity for diagnosis of acute mesenteric ischemia.

KEY POINTS

• Split-bolus CTA protocol for mesenteric ischemia has great diagnostic accuracy with lower radiation exposure and fewer images to interpret compared with standard multiphasic CTA.

Lipoma of the transverse colon covered by tubulovillous adenoma: a rare indication for surgical treatment

Lipomas of the digestive tract are rare benign tumours which, in most cases, are totally asymptomatic. Because of their localization within the intestinal wall, endoscopy may be completely negative so contrast-enhanced computed tomography (CT) is very important for detecting and typing these lesions. The case of a 49-year-old man with abdominal pain is presented. Colonoscopy and biopsy of a polypoid lesion on the right colonic flexure concluded for tubulovillous adenoma. The subsequent CT showed a polylobate lesion of 5 cm in diameter with predominant fat density causing luminal sub-stenosis. Histological examination of the surgical specimen confirmed the presence of a voluminous submucosal lipoma. CT allows to diagnose lipomas of the large bowel thanks to the density measurement (between -40 and -120 Hunsfield Units) with an accurate detection of the site and nature of lumen stenosis.

Mesenteric ischemia: what the radiologist needs to know

Acute mesenteric ischemia (AMI) is a life-threatening condition that often presents with abdominal pain. Early diagnosis with contrast-enhanced computed tomography and revascularization can reduce the overall mortality in AMI. This article reviews practical etiological classification, pathophysiology of imaging manifestations and common pitfalls in intestinal ischemia.

Reversible pneumatosis cystoides intestinalis after liver transplantation

Pneumatosis cystoides intestinalis (PCI) is a rare disease characterized by the presence of multiple gas-filled cysts within the submucosa or subserosa of the intestinal wall. We report a case of PCI in a 54-yearold man 4 weeks after liver transplantation due to hepatitis B virus (HBV)-associated liver cirrhosis presenting with illness, diarrhea and abdominal pain. CT scans revealed normal shape of the abdominal parenchymal organs and no intra-hepatic complication due to liver transplantation. Main abdominal venous and arterial vessels resulted patent. Colic loops appeared diffusely thickened for the presence of variable diameter air-filled cysts located within the bowel wall. The patient underwent conservative treatment and the CT control after 4 weeks showed a complete PCI resolution. PCI after adult liver transplantation is probably due to the pre-transplantation chemotherapy, immunosuppressive therapy and opportunistic enteric infections. Abdominal CT represents the gold standard technique for diagnosing PCI and for evaluating its extension and complications providing data on other abdominal pathologies. It appears as variable diameter gas-filled cysts located within the bowel wall and it is often associated with pneumo-peritoneum probably due to the rupture of subserosal cysts. PCI has a favorable outcome and requires conservative treatment. Major differential diagnosis includes intestinal pneumatosis due to bowel ischemia. PCI after liver transplantation represents an uncommon bowel disease with a favorable prognosis. CT represents the reference imaging technique for diagnosing the disease and evaluating the response to therapy which is usually conservative rather than surgical.

Predictive Risk Factors of Intestinal Necrosis in Patients with Mesenteric Venous Thrombosis: Retrospective Study from a Single Center

PURPOSES

Mesenteric venous thrombosis (MVT) is a serious condition. The current study aimed to identify risk factors of intestinal necrosis (IN) in patients with MVT to predict the onset of patients.

METHODS

Data pertaining to patients diagnosed with MVT between 2014 and May 2018 were reviewed. Patients' characteristics and risk factors of IN were assessed.

RESULTS

Seventy-eight patients were included in our study, of whom all cases were diagnosed as superior mesenteric venous thrombosis. There were fifty-eight cases (74%) with intestinal necrosis and twenty cases (26%) without intestinal necrosis. Multivariate analysis of factors associated with IN was organ failure (odds ratio (OR): 4.1; 95% confidence interval (95%CI): 1.26-8.59; P=0.028), elevated serum lactate (OR:3.6; 95% CI: 1.51-5.47; P=0.024), bowel loop dilation on computerized tomography (CT) scan (OR: 2.8; 95% CI: 1.32-7.23; P=0.031), and the time between onset of symptoms and operation (OR: 4.8; 95% CI: 1.36-9.89; P=0.012). Area under the receiver operating characteristics curve for the diagnosis of IN with MVT was 0.901 (95%CI: 0.809-0.993; P=0.000) depending on the different number of predictive factors.

CONCLUSION

Predictive risk factors for IN with MVT were organ failure, elevated serum lactate level, bowel loop dilation on CT, and the time between onset of symptoms and operation. However, this result is from a retrospective study and further long-term, large-sample prospective studies are required to confirm this finding.

A strategy for improving the prognosis of non-occlusive mesenteric ischemia (NOMI): a single-center observational study

Aim

The purpose of this study was to determine the prognostic factors of non‐occlusive mesenteric ischemia (NOMI) and to examine treatment strategies that could improve its prognosis.

Methods

We retrospectively identified 30 patients who underwent emergency laparotomy for NOMI in Kansai Medical University Hospital (Hirakata, Japan) from April 2013 to December 2017. We examined prognostic factors related to discharge outcome and also examined the prognostic impact of open abdominal management and second look operation strategy (OSS) by dividing the patients into the non‐OSS group and the OSS group.

Results

The primary end‐point was a prognostic factor for outcome at discharge of the 30 patients. The outcome at discharge was compared between the survival group and the death group. Multivariate analysis was undertaken on two items from the univariate analysis that showed a significant difference (computed tomography findings of intestinal pneumatosis and acute disseminated intravascular coagulation [DIC] score). As a result, there was a significant difference in the factors of intestinal pneumatosis (odds ratio = 0.054; 95% confidence interval, 0.005–0.607; P = 0.018) and DIC score (odds ratio = 1.892; 95% confidence interval, 1.077–3.323; P = 0.027). The secondary end‐point was the treatment outcome before and after the application of OSS. Operation time was significantly shorter and the amount of bleeding was also significantly less in the OSS group.

Conclusion

Computed tomography findings of intestinal pneumatosis and the acute disseminated intravascular coagulation score were found to be prognostic factors for survival in patients with NOMI. Aggressive laparotomy to determine the definitive diagnosis is needed and OSS could be useful to improve patient prognosis for survival from NOMI.

Non-occlusive mesenteric ischemia: two case reports and a short review of the literature

INTRODUCTION

Non-occlusive mesenteric ischemia (NOMI) is an infrequent cause of acute mesenteric ischemia with atypical symptoms and a high mortality.

PATIENTS AND METHODS

We report two cases of NOMI characterized by their difference in etiology, treatment and outcome.

RESULTS

In the first case, the patient developed NOMI after septic shock, she was successfully treated with surgery. The second patient experienced two episodes of cardiac arrest followed by NOMI. He received only supportive care and died shortly after. We present a short review of the literature, discussing epidemiology, pathophysiology, clinical presentations, diagnosis and management of NOMI.

CONCLUSION

NOMI is a rare disease with a difficult diagnosis. Early recognition and treatment with supportive therapy, vasodilator drugs and possibly surgery can significantly lower mortality.

Factors Associated With in-Hospital Death in Patients with Acute Mesenteric Artery Ischemia

Objective: The aim of the study was to assess the factors associated with increased mortality in patients with acute mesenteric ischemia, emphasizing the importance of an early diagnosis and a prompt surgical intervention in order to avoid lesion progression. Materials and method: A retrospective analytical study was conducted on a study population of 50 male and female patients with acute ischemia of the mesenteric arteries, aged between 36-92 years. Demographic and pathological history characteristics were assessed, together with presented symptoms, laboratory and CT findings, as well as surgical outcome and time-related aspects between presentation in the emergency department and time of surgery, as well as the hospitalization period until discharge or death. Results: Muscular defense (OR = 23.05) and shock (OR = 13.24) as symptoms were strongly associated with a poor prognosis, while elevated values of lactate dehydrogenase (p = 0.0440) and creatine kinase (p = 0.0025) were associated with higher death rates. The time elapsed during investigations in the emergency room was significantly higher in patients who deceased (p = 0.0023), similarly to the total time from the onset of symptoms to the beginning of surgery (p = 0.0032). Surgical outcomes showed that patients with segmental ischemia of the small bowel had significantly higher chances of survival (p <0.0001). Conclusion: Increased mortality rates in patients presenting in the emergency department for acute mesenteric ischemia were observed in patients with occlusion of the superior mesenteric artery, with higher levels of CK and LDH, as well as with longer periods of stay in the emergency department for diagnostic procedures until the commencement of the surgical intervention. Therefore, proper investigations in a timely manner followed by a specific and prompt surgical intervention may avoid unfavorable evolution of patients towards death.

Inter-reader agreement of CT features of acute mesenteric ischemia

PURPOSE

To evaluate the inter-reader agreement of the CT features of acute mesenteric ischemia (AMI).

METHODS

Between 2006 and 2014, 109 patients (57 men, 52%, mean age 50 years old [17-83]) admitted to our institution with a diagnosis of AMI were included. CT scans (42% were initially performed in our institution) were reviewed by two abdominal radiologists. Inter-observer agreement of the imaging features of vascular insufficiency and bowel ischemia was assessed by the percentage of agreement and the kappa value.

RESULTS

The final population included, Inter-observer agreement varied according to the different features (κ = 0.25-0.98). Inter-observer agreement for decreased/absent bowel wall enhancement was moderate (κ = 0.52), but was almost perfect (κ = 0.82) in the 47 patients (43%) with both unenhanced and arterial-phase images without positive oral contrast agent and excellent CT images quality.

CONCLUSION

Inter-reader agreement was moderate to substantial for most CT features of AMI. Multiphasic CT scan protocol, including unenhanced, arterial phase and venous phase images, without positive oral contrast agent, and excellent CT images quality improve inter-observer agreement of imaging features of AMI, especially for decreased/absent bowel wall enhancement, and should be performed in patients with suspected AMI.

Utility of multiple rule out CT screening of high-risk atraumatic patients in an emergency department-a feasibility study

BACKGROUND

Several large trials have evaluated the effect of CT screening based on specific symptoms, with varying outcomes. Screening of patients with CT based on their prognosis alone has not been examined before. For moderate-to-high risk patients presenting in the emergency department (ED), the potential gain from a CT scan might outweigh the risk of radiation exposure. We hypothesized that an accelerated "multiple rule out" CT screening of moderate-to-high risk patients will detect many clinically unrecognized diagnoses that affect change in treatment.

METHOD

Patients ≥ 40 years, triaged as high-risk or moderate-to-high risk according to vital signs, were eligible for inclusion. Patients were scanned with a combined ECG-gated and dual energy CT scan of cerebrum, thorax, and abdomen. The impact of the CT scan on patient diagnosis and treatment was examined prospectively by an expert panel.

RESULTS

A total of 100 patients were included in the study, (53% female, mean age 73 years [age range, 43-93]). The scan lead to change in treatment or additional examinations in 37 (37%) patients, of which 24 (24%) were diagnostically significant, change in acute treatment in 11 (11%) cases and previously unrecognized malignant tumors in 10 (10%) cases. The mean size specific radiation dose was 15.9 mSv (± 3.1 mSv).

CONCLUSION

Screening with a multi-rule out CT scan of high-risk patients in an ED is feasible and result in discovery of clinically unrecognized diagnoses and malignant tumors, but at the cost of radiation exposure and downstream examinations. The clinical impact of these findings should be evaluated in a larger randomized cohort.

Gastrointestinal tract involvement in acute pancreatitis: initial findings and follow-up by magnetic resonance imaging

BACKGROUND

To study the initial and follow up patterns of gastrointestinal tract involvement in acute pancreatitis (AP) using magnetic resonance imaging (MRI).

METHODS

A total of 209 patients with AP undergoing abdominal MRI on 1.5 T MRI were compared to 100 control patients selected from our daily clinical caseload who underwent MRI over the same recruitment period and had no other disease which can cause abnormality of gastrointestinal tract. Initial and follow up MRI examinations of gastrointestinal tract abnormalities were noted for AP patients. The severity of AP was graded by the MRSI and APACHE II. Spearman correlation of gastrointestinal tract involvement with MRSI and APACHE II was analyzed.

RESULTS

In 209 patients with AP, 63% of the AP patients on their initial MRI exams and 5% of control subjects had at least one gastrointestinal tract abnormality (P<0.05). In the control group, thirty-seven patients were normal on MRI, 24 patients with renal cysts, eighteen patients with liver cysts, eleven patients with liver hemangiomas, and ten patients with splenomegaly. The abnormalities of gastrointestinal tract observed in AP patients included thickened stomach wall (20%), thickened duodenum wall (27%), thickened ascending colon wall (11%), thickened transverse colon wall (15%), and thickened descending colon wall (26%), among others. Gastrointestinal tract abnormalities were correlated with the MRSI score (r=0.46, P<0.05) and APACHE II score (r=0.19, P<0.05). Among 62 patients who had follow up examinations, 26% of patients had gastrointestinal tract abnormality, which was significantly lower than that in the initial exams (P<0.05). Resolution of gastrointestinal tract abnormal MRI findings coincided with symptom alleviation in AP patients.

CONCLUSIONS

Gastrointestinal tract abnormalities on MRI are common in AP and they are positively correlated with the severity of AP. It may add value for determining the severity of AP.

Non-occlusive mesenteric ischaemia: CT findings, clinical outcomes and assessment of the diameter of the superior mesenteric artery

OBJECTIVE

Review of the experience of a tertiary care centre for almost 10 years in the CT diagnosis of non-occlusive mesenteric ischaemia (NOMI). Analysis of CT findings, correlation with clinical outcomes and evaluation of the usefulness of measuring the superior mesenteric artery (SMA) diameter for the diagnosis of NOMI.

METHODS

106 patients were diagnosed with NOMI in a biphasic CT examination from 2008 to 2017 in our hospital. Clinical outcomes and CT findings were reviewed. In 55 patients, the diameter of the SMA was compared with a previous CT scan where NOMI was not the diagnosis, and statistical analysis using paired t-test was performed.

RESULTS

81 patients (76%) had findings consistent with small bowel ischaemia and the ileum was the segment most commonly involved (47%). Lack of wall enhancement, pneumoperitoneum, pneumatosis intestinalis and portal venous gas were all considered signs of bowel necrosis and surgery was performed promptly. 70 patients had signs of vascular narrowing of the SMA branches and in the 55 cases with a previous CT scan, there were statistically significant differences regarding the SMA diameter with a mean reduction of the artery calibre and standard deviation of 1.93 ± 1.1 mm between the NOMI and non-NOMI scans (p < 0.001).

CONCLUSION

Acknowledgment of characteristic bowel necrosis CT findings is crucial for determining the therapeutic attitude and the use of previous CT scans to compare the SMA diameter may help the radiologist to achieve an early diagnosis of NOMI in an often critically ill patient population. Advances in knowledge: Diagnosis of NOMI can be difficult in cases of partial mural ischaemia, thus objective data (diameter of the SMA) should be useful for the radiologist to include NOMI as the first diagnostic option in the differential diagnosis.

Feeding Jejunostomy-Associated Small Bowel Necrosis After Elective Esophago-Gastric Resection

BACKGROUND

Feeding jejunostomy has increasingly become a standard adjunctive procedure during major esophago-gastric resections. They provide nutritional support during the post-operative period as required. However, significant early complications have been reported, most notably small bowel necrosis. Literature reports have been restricted to case reports or series. This study aims to determine the frequency of this complication in a cohort of patients undergoing esophago-gastric resection, and identify any difference in the risk of this complication between patients undergoing esophagectomy and gastrectomy.

METHODS

Consecutive patients who had esophago-gastric resections for malignancy and who had a feeding jejunostomy placed were identified from a prospectively maintained database at Leicester Royal Infirmary during the years 2009-2015. Case notes were reviewed to extract information relating to demographics, presenting features and clinical outcome.

RESULTS

The study included 360 patients, 285 of which had esophagectomy and 75 had gastrectomy. There were no small bowel complications among esophagectomy patients (0%), while six patients who had total gastrectomy developed small bowel ischemia or necrosis (8%), p = 0.05, in spite of an identical feeding regimen. Every patient that developed the complication underwent surgery with five out six having resection of the infarcted segment and double-barrel stoma formation. A 6-8-week period of parenteral nutrition was required before stoma reversal. One patient had leucocytosis on the day of diagnosis. The other five patients showed no derangements in biochemical or clinical parameters in the preceding 48 h. Five of the six patients survived.

CONCLUSIONS

Small bowel necrosis and perforation is a life-threatening complication of feeding jejunostomy. In our cohort, it happened exclusively in total gastrectomy patients. Antecedent signs were lacking. The condition requires prompt attention with earlier use of CT scanning and a return to the operating room. The presence of pneumatosis intestinalis on CT scan should prompt surgical intervention that improves survival.

Ischemic colitis of the colon in streptozotocin-induced diabetic rats

This study focuses on two inflammatory diseases, viz., "diabetes mellitus (DM)" that causes serious complications such as retinopathy, nephropathy, and neuropathy, and "ischemic colitis" which is evoked by DM. Ischemic colitis originates from the reduction in mesenteric blood flow to the colon with existence of the occlusive or non-occlusive reasons. Our study objective was to provide early diagnostic approach for ischemic colitis in streptozotocin (STZ)-induced diabetic rats. Sprague-Dawley rats were divided into four groups: (i) control use of 0.1 M citrate buffer, the solvent of streptozotocin (C), (ii). induced ischemia (I), (iii) rats subjected to 60 mg/kg STZ intraperitoneally to induce type 1 diabetes (D) (48 h after STZ injection, blood glucose levels >200 mg/dl were considered as diabetic), and (iv) diabetic rats subjected to intestinal ischemia (D+I). The third diabetic group (D) was not operated. At the end of the experimental period, rats were sacrificed, C-reactive protein (CRP) and calprotectin levels were measured in the serum and colon tissue specimens. Tissue specimens were also analyzed histologically. We found that serum and colon calprotectin levels were elevated in the D+I group compared to the D and/or I group alone, but relatively calprotectin levels increased in I as compared to C group in colon tissues. CRP levels were significantly increased with ischemic colitis in diabetes, while colon CRP levels were decreased. These results provide evidence for the existence of inflammation in the STZ-induced diabetic rats with ischemic colitis. In conclusion, our measurements of serum calprotectin levels of STZ-induced diabetic rats with ischemic colitis provide a practical approach for an early diagnosis of ischemic colitis. Furthermore, these biochemical analyses correlate well with the histopathologic findings of STZ-induced diabetic rats with ischemic colitis. Future studies would be desirable to further strengthen the role of calprotectin in the early diagnosis of ischemic colitis in diabetics clinical settings.

Conservative Management of Spontaneous Isolated Dissection of the Superior Mesenteric Artery

Purpose

We report the clinical outcomes of patients with spontaneous isolated dissection of the superior mesenteric artery (SIDSMA) who were treated conservatively.

Materials and Methods

A retrospective review was performed in 14 patients from 2006 to 2016 with SIDSMA. Their clinical features and computed tomographic angiography (CTA) characteristics, treatment methods, and clinical outcomes were analyzed. The mean age was 53.6 (range, 41–73) years, and the mean follow-up duration was 20.6 (range, 1–54) months. Conservative management was the primary treatment if no bowel ischemia or arterial rupture was noted.

Results

The mean initial abdominal visual analog pain score was 7 (range, 5–9) in seven patients. The mean total duration of abdominal pain was 10.2 days (range, 2–42 days) in 10 patients. The mean percentage stenosis of the dissected SMA at the initial presentation was 78.8% in 14 patients. Complete obstruction of the SMA at the initial presentation was evident in 4 of the 14 patients (28.6%). Conservative management was successful in all 14 patients. None of the 14 patients developed bowel ischemia or an infarction. Abdominal pain did not recur in any patient during follow-up (mean, 20.6 months; range, 1–54 months).

Conclusion

Conservative management was successful for all SIDSMA patients, even those with severe compression of the true lumen or complete obstruction of the dissected SMA.

Gastrointestinal manifestations of Henoch-Schonlein purpura: A report of two cases

Henoch-Schonlein purpura (HSP) is a small vessel vasculitis mediated by type III hypersensitivity with deposition of IgA immune complex in the walls of vessels. It is a multi-system disorder characterized by palpable purpura, arthritis, glomerulonephritis and gastrointestinal manifestations and commonly occurs in children and young adults. The patients with gastrointestinal involvement usually present with colicky abdominal pain, vomiting and melena. The imaging findings include multifocal bowel thickening with mucosal hyperenhancement, presence of skip areas, mesenteric vascular engorgement, with involvement of unusual sites like stomach, duodenum and rectum. These imaging findings in a child or young adult with appropriate clinical findings could suggest HSP.