CT diagnosis of small-bowel obstruction: efficacy in 60 patients

An authentic radiological triad of Rigler allowing the diagnosis of gallstone ileus: A case report

The Rigler's Triad consists by three radiological signs, including intestinal obstruction, pneumobilia, and an aberrant gallstone in the bowel. It is an inconstant triad considered being pathognomonic of gallstone ileus. Gallstone ileus is an exceptional complication of cholelithiasis due to the passage of one or more gallstones from the bile ducts into the lumen of the bowel through a biliodigestive fistula. We report the case of an 83-year-old female patient with a history of ischemic heart disease and an asymptomatic large gallstone. The patient was admitted to the emergency department for bowel obstruction, abdominal pain, and bilious vomiting. A clinical examination found a patient with an alteration in general condition and a distended abdomen with tenderness. An abdominal CT scan revealed Rigler's triad, allowing the diagnosis of gallstone ileus. A midline exploratory laparotomy was performed to find a giant gallstone blocked in the last ileum loop. A simple enterolithotomy was performed, allowing the extraction of giant lithiasis from an 8-cm major axis. The postoperative evolution was uneventful, and the patient was discharged 4 days after surgical treatment.

Pearls and Pitfalls of Imaging Small Bowel Obstruction

Small bowel obstruction (SBO) is a common condition encountered by radiologists in the evaluation of patients with abdominal pain, and is an important diagnosis to be comfortable with given substantial associated morbidity and mortality. In this review, we summarize an imaging approach to evaluating patients with suspected SBO, discuss the role of certain imaging modalities such as radiography and small bowel follow through, CT, and MRI, as well as review some common and also less common causes of SBO such as internal hernia. We will also discuss tailoring the imaging approach to address specific clinical questions and special patient populations such as imaging the pregnant patient with suspected SBO, and the inflammatory bowel disease patient.

Deep learning for automatic bowel-obstruction identification on abdominal CT

RATIONALE AND OBJECTIVES

Automated evaluation of abdominal computed tomography (CT) scans should help radiologists manage their massive workloads, thereby leading to earlier diagnoses and better patient outcomes. Our objective was to develop a machine-learning model capable of reliably identifying suspected bowel obstruction (BO) on abdominal CT.

MATERIALS AND METHODS

The internal dataset comprised 1345 abdominal CTs obtained in 2015-2022 from 1273 patients with suspected BO; among them, 670 were annotated as BO yes/no by an experienced abdominal radiologist. The external dataset consisted of 88 radiologist-annotated CTs. We developed a full preprocessing pipeline for abdominal CT comprising a model to locate the abdominal-pelvic region and another model to crop the 3D scan around the body. We built, trained, and tested several neural-network architectures for the binary classification (BO, yes/no) of each CT. F1 and balanced accuracy scores were computed to assess model performance.

RESULTS

The mixed convolutional network pretrained on a Kinetics 400 dataset achieved the best results: with the internal dataset, the F1 score was 0.92, balanced accuracy 0.86, and sensitivity 0.93; with the external dataset, the corresponding values were 0.89, 0.89, and 0.89. When calibrated on sensitivity, this model produced 1.00 sensitivity, 0.84 specificity, and an F1 score of 0.88 with the internal dataset; corresponding values were 0.98, 0.76, and 0.87 with the external dataset.

CONCLUSION

The 3D mixed convolutional neural network developed here shows great potential for the automated binary classification (BO yes/no) of abdominal CT scans from patients with suspected BO.

CLINICAL RELEVANCE STATEMENT

The 3D mixed CNN automates bowel obstruction classification, potentially automating patient selection and CT prioritization, leading to an enhanced radiologist workflow.

KEY POINTS

• Bowel obstruction's rising incidence strains radiologists. AI can aid urgent CT readings. • Employed 1345 CT scans, neural networks for bowel obstruction detection, achieving high accuracy and sensitivity on external testing. • 3D mixed CNN automates CT reading prioritization effectively and speeds up bowel obstruction diagnosis.

Deep learning using computed tomography to identify high-risk patients for acute small bowel obstruction: development and validation of a prediction model : a retrospective cohort study

OBJECTIVE

To build a novel classifier using an optimized 3D-convolutional neural network for predicting high-grade small bowel obstruction (HGSBO).

SUMMARY BACKGROUND DATA

Acute SBO is one of the most common acute abdominal diseases requiring urgent surgery. While artificial intelligence and abdominal computed tomography (CT) have been used to determine surgical treatment, differentiating normal cases, HGSBO requiring emergency surgery, and low-grade SBO (LGSBO) or paralytic ileus is difficult.

METHODS

A deep learning classifier was used to predict high-risk acute SBO patients using CT images at a tertiary hospital. Images from three groups of subjects (normal, nonsurgical, and surgical) were extracted; the dataset used in the study included 578 cases from 250 normal subjects, with 209 HGSBO and 119 LGSBO patients; over 38 000 CT images were used. Data were analyzed from 1 June 2022 to 5 February 2023. The classification performance was assessed based on accuracy, sensitivity, specificity, and area under the receiver operating characteristic curve.

RESULTS

After fivefold cross-validation, the WideResNet classifier using dual-branch architecture with depth retention pooling achieved an accuracy of 72.6%, an area under receiver operating characteristic of 0.90, a sensitivity of 72.6%, a specificity of 86.3%, a positive predictive value of 74.1%, and a negative predictive value of 86.6% on all the test sets.

CONCLUSIONS

These results show the satisfactory performance of the deep learning classifier in predicting HGSBO compared to the previous machine learning model. The novel 3D classifier with dual-branch architecture and depth retention pooling based on artificial intelligence algorithms could be a reliable screening and decision-support tool for high-risk patients with SBO.

Case report: caught by the pill cam…literally

Small bowel obstructions are a common general surgery occurrence. In a patient with prior abdominal surgeries, the usual diagnosis is secondary to adhesions. The management is typically conservative, which usually avoids operative intervention. Computed tomography (CT) scans help diagnosticians take a snapshot inside the abdomen; however, CT scans are not perfect and intra-abdominal pathologies can be missed requiring surgery. We present a case of an atypical small bowel obstruction. The initial CT scan showed a transition point in the right lower quadrant, which was managed non-operatively. One week later, the patient then re-presented with hematochezia following an outpatient pill cam procedure. Imaging showed the presence of a new small bowel mass, which was not seen on imaging done 1 week ago or from 10 months prior. He was then taken for a diagnostic laparoscopy, in which a small bowel mass was found, pathology positive for recurrent renal cell carcinoma.

Small bowel obstruction and intestinal ischemia: emphasizing the role of MDCT in the management decision process

The objective of this article is to assess the computed tomography (CT) findings of small bowel obstruction (SBO) complicated by ischemia. SBO is a frequent clinical entity characterized by high morbidity and mortality. The radiologic aim is not just to diagnose the obstruction itself but to rule out the presence of complications related to SBO. This is crucial for differentiating which patients can be safely treated non-operatively from the ones who may need an urgent surgical approach. The main complication of SBO is intestinal ischemia. In the emergency setting, CT imaging is the modality of choice for SBO because of its ability to assess the bowel wall, the supporting mesentery and peritoneal cavity all in one. On the other hand, the radiologist who documents an intestinal ischemia should think about SBO as possible cause. In this case, the main finding which helps the radiologist in the identification of SBO is the presence of multiple and packed valvulae conniventes in the dilated bowel wall and the "transition zone" that indicates the passage between compressed and decompressed small bowel, otherwise the localization of the obstruction cause. Once the site of obstruction has been recognized, the other issue is to assess the cause of obstruction, considering that the most common cause of SBO remains "unidentified" and related to intra-abdominal adhesions. After that, the following most important point is to rule out the presence of an ischemic bowel and mesenteric changes associated to SBO. CT signs of bowel ischemia include reduced or increased bowel wall enhancement, mesenteric edema or engorgement, fluid or free air in the peritoneal cavity. This condition usually leads to an urgent laparotomy and, in some cases, to a surgical resection.

Routine versus selective computed tomography in non-traumatic acute abdominal pain: meta-analysis of randomised trials

PURPOSE

To compare the routine vs. selective use of computed tomography (CT) in patients presenting with non-traumatic acute abdominal pain (AAP) to a surgical service.

METHODS

We conducted a systematic review of literature and meta-analysis of outcomes according to PRISMA statement standards to compare the routine vs. selective use of CT in adult patients presenting with non-traumatic AAP.

RESULTS

Analysis of 722 patients from 4 randomised controlled trials showed no difference between the routine CT and selective CT groups in terms of proportion of correct diagnoses (OR 1.36,95% CI 0.89, 2.07, P = 0.15), mortality (RD 0.03, 95% CI - 0.08, 0.02, P = 0.27] and length of hospital stay (LOS) [MD - 0.26, 95% CI - 2.07, 1.55, P = 0.78).

CONCLUSIONS

The routine use of CT does not improve the proportion of correct diagnoses and mortality compared to selective use of CT in adult patients with non-traumatic AAP. The available evidence regarding the influence of routine CT on LOS may be subject to type 2 error. These findings, however, may not apply to the elderly patient with AAP and further studies are required.

ACR Appropriateness Criteria® Suspected Small-Bowel Obstruction

Small-bowel obstruction is a common cause of abdominal pain and accounts for a significant proportion of hospital admissions. Radiologic imaging plays the key role in the diagnosis and management of small-bowel obstruction as neither patient presentation, the clinical examination, nor laboratory testing are sufficiently sensitive or specific enough to diagnose or guide management. This document focuses on the imaging evaluation of the two most commonly encountered clinical scenarios related to small-bowel obstruction: the acute presentation and the more indolent, low-grade, or intermittent presentation. This document hopes to clarify the appropriate utilization of the many imaging procedures that are available and commonly employed in these clinical settings. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Diagnostic utility of CT for small bowel obstruction: Systematic review and meta-analysis

BACKGROUND

To perform a systematic review and meta-analysis evaluating the diagnostic performance of computed tomography (CT) for small bowel obstruction (SBO), including diagnostic accuracy, ischemia, predicting surgical intervention, etiology and transition point.

METHODS

PubMed/MEDLINE and related databases were searched for research articles published from their inception through August 2018. Findings were pooled using bivariate random-effects and summary receiver operating characteristic curve models. Meta-regression and subgroup analyses were performed to evaluate whether publication year, patient age, enhanced CT, slice thickness and pathogenesis affected classification accuracy.

RESULTS

In total, 45 studies with a total of 4004 patients were included in the analysis. The pooled sensitivity and specificity of CT for SBO were 91% (95% confidence interval [CI]: 84%, 95%) and 89% (95% CI: 81%, 94%), respectively, and there were no differences in the subgroup analyses of age, publication year, enhanced CT and slice thickness. For ischemia, the pooled sensitivity and specificity was 82% (95% CI: 67%, 91%) and 92% (95% CI: 86%, 95%), respectively. No difference was found between enhanced and unenhanced CT based on subgroup analysis; however, high sensitivity was found in adhesive SBO compared with routine causes (96% vs. 78%, P = 0.03). The pooled sensitivity and specificity for predicting surgical intervention were 87% and 73%, respectively. The accuracy for etiology of adhesions, hernia and tumor was 95%, 70% and 82%, respectively. In addition, the pooled sensitivity and specificity for transition point was 92% and 77%, respectively.

CONCLUSIONS

CT has considerable accuracy in diagnosis of SBO, ischemia, predicting surgical intervention, etiology and transition point.

The value of the erect abdominal radiograph for the diagnosis of mechanical bowel obstruction and paralytic ileus in adults presenting with acute abdominal pain

INTRODUCTION

There is discord on the value of the erect abdominal radiograph for diagnosing acute abdominal pathologies. The erect radiograph can be uncomfortable for patients in pain and increases patient radiation dose.

AIM

To determine if including the erect abdominal radiograph in plain abdominal radiography (PAR) improved diagnostic accuracy for identifying mechanical bowel obstruction and/or paralytic ileus in adults presenting with acute abdominal pain.

METHODS

PAR of 40 consecutive adults presenting with suspected bowel obstruction or paralytic ileus was retrospectively sampled and independently reviewed by two emergency department (ED) consultants and two radiology consultants for bowel obstruction and paralytic ileus across two sessions. In session 1, the assessors assessed the supine abdominal radiographs (PAR 1) and clinical details in a randomised order, and session 2, at least 6 weeks later, they assessed the supine and erect radiographs (PAR 2) and clinical details of the randomly re-ordered cases. Computed tomography was the reference standard. Pair-wise comparisons of receiver operating characteristic curves were calculated to assess for significant differences in participants' diagnostic accuracy using MedCalc 16.4.3.

RESULTS

Average sensitivity, specificity and area under the receiver operating characteristic curves (AUROC) were 69.7%, 61.0% and 0.642 for PAR 1, respectively, and 80.0%, 53.4% and 0.632 for PAR 2 respectively. For AUROC there were no significant differences (P > 0.05) between PAR 1 and PAR 2. Intra-rater and inter-rater agreement improved in PAR 2.

CONCLUSION

There was no statistically significant improvement in diagnostic accuracy when including the erect radiograph in PAR for the acute abdomen.

Small Bowel Obstruction

Identifying patients with small bowel obstruction who need operative intervention and those who will fail nonoperative management is a challenge. Without indications for urgent intervention, a computed tomography scan with/without intravenous contrast should be obtained to identify location, grade, and etiology of the obstruction. Most small bowel obstructions resolve with nonoperative management. Open and laparoscopic operative management are acceptable approaches. Malnutrition needs to be identified early and managed, especially if the patient is to undergo operative management. Confounding conditions include age greater than 65, post Roux-en-Y gastric bypass, inflammatory bowel disease, malignancy, virgin abdomen, pregnancy, hernia, and early postoperative state.

A Systematic Review of the Clinical Presentation, Diagnosis, and Treatment of Small Bowel Obstruction. Curr Gastroenterol Rep. 2017;19:28. [PMID: 28439845 DOI: 10.1007/s11894-017-0566-9]

PURPOSE OF REVIEW

This study aimed to systematically review small bowel obstruction (SBO), focusing on recent changes in diagnosis/therapy.

RECENT FINDINGS

SBO incidence is about 350,000/annum in the USA. Etiologies include adhesions (65%), hernias (10%), neoplasms (5%), Crohn's disease (5%), and other (15%). Bowel dilatation occurs proximal to obstruction primarily from swallowed air and secondarily from intraluminal fluid accumulation. Dilatation increases mural tension, decreases mucosal perfusion, causes bacterial proliferation, and decreases mural tensile strength that increases bowel perforation risks. Classical clinical tetrad is abdominal pain, nausea and emesis, abdominal distention, and constipation-to-obstipation. Physical exam may reveal restlessness, acute illness, and signs of dehydration and sepsis, including tachycardia, pyrexia, dry mucous membranes, hypotension/orthostasis, abdominal distention, and hypoactive bowel sounds. Severe direct tenderness, involuntary guarding, abdominal rigidity, and rebound tenderness suggest advanced SBO, as do marked leukocytosis, neutrophilia, bandemia, and lactic acidosis. Differential diagnosis includes postoperative ileus, narcotic bowel, colonic pseudo-obstruction, mesenteric ischemia, and large bowel obstruction. Medical resuscitation includes intravenous hydration, correcting electrolyte abnormalities, intravenous antibiotics, nil per os, and nasoenteral suction. Abdominal CT with oral and intravenous gastrografin contrast is highly sensitive and specific in detecting/characterizing SBO. SBO usually resolves with medical therapy but requires surgery, preferentially by laparoscopy, for unremitting total obstruction, bowel perforation, severe ischemia, or clinical deterioration with medical therapy. Overall mortality is 10% but increases to 30% with bowel necrosis/perforation. Key point in SBO is early diagnosis, emphasizing abdominal CT; aggressive medical therapy including rehydration, antibiotics, and nil per os; and surgery for failed medical therapy.

Accuracy of Plain Abdominal Radiography in the Differentiation between Small Bowel Obstruction and Small Bowel Ileus in Acute Abdomen Presenting to Emergency Department

Introduction

Our purpose was to evaluate whether plain abdominal radiography (PAR) could accurately differentiate between small bowel obstruction (SBO) and small bowel ileus (SBI) in an emergency setting. We also evaluated the value of known classic signs on the PAR for differentiating between SBO and SBI.

Methods

This retrospective study included 216 emergency room patients who had small bowel distension (maximal small bowel diameter ≥2.5 cm) on the PAR and who underwent successive abdominal computed tomography. One radiologist and one emergency physician retrospectively reviewed PAR in consensus, unaware of the patients' clinical data; they divided the patients into an SBO group and an SBI group according to the radiographic findings. Presence or numeric values of 10 radiographic signs were also recorded. Final diagnoses of SBO and SBI were established by a combined analysis of medical charts, surgical records, radiographic findings on abdominal computed tomography, and small bowel studies. The differential diagnoses based on PAR and the final diagnoses were compared, and the sensitivity and specificity of PAR were calculated. We also evaluated the differences among 10 radiographic signs between the final SBO and SBI groups.

Results

Sensitivity and specificity of PAR for SBO were 82.0% and 92.4%, respectively. Among the 10 radiographic signs, all except maximal colon diameter were statistically significant predictors on the final diagnosis.

Conclusions

PAR is an accurate and effective initial imaging modality for differentiating between SBO and SBI in an emergency setting, and most of the classic radiographic signs have a diagnostic value.

Acute Bowel Computed Tomography

Acute abdominal pain is a common presenting complaint in the emergency department. Increasingly, computed tomography is utilized for evaluating these patients. Radiologists are therefore expected to be familiar with the pertinent clinical and radiologic information related to acute bowel pathology. This primer will review the need-to-know and latest updates related to computed tomography evaluation of acute bowel pathology.

Impact of high-grade obstruction on outcomes in patients with appendiceal inflammatory masses managed by nonoperative treatment

Purpose

To retrospectively assess the impact of high-grade obstructions identified on initial CT on outcomes of patients with appendiceal inflammatory masses managed by nonoperative treatment.

Methods

Institutional Review Boards approved this retrospective study and informed consent was waived. Included were 52 consecutive patients diagnosed with appendiceal inflammatory masses by CT scan and managed by nonoperative treatment. The main outcome measure was treatment failure and secondary outcomes were complications and initial and total hospital stay. Patient demographics, inflammatory markers, and CT findings for presence of an appendiceal inflammatory mass and high-grade obstruction were assessed. Patients with and without high-grade obstruction were compared for patient characteristics and outcomes using Fisher exact test and Student t-test.

Results

Among 52 patients, 14 (27%) had high-grade obstruction on CT examination at presentation. No significant differences were observed in patient characteristics (P > 0.05), treatment failure (P = 0.33), complications (P = 0.29), or initial (P = 0.73) or total (P = 0.72) hospitalization between patients with and without high-grade obstruction.

Conclusion

For patients who were managed by nonoperative treatment for appendiceal inflammatory masses, the presence of high-grade obstruction identified on initial CT scan did not significantly affect outcomes of treatment failure, complications, and initial and total hospitalization.

Value of MDCT and Clinical and Laboratory Data for Predicting the Need for Surgical Intervention in Suspected Small-Bowel Obstruction. AJR Am J Roentgenol. 2017;208:785-793. [PMID: 28328258 DOI: 10.2214/ajr.16.16946]

OBJECTIVE

The purpose of this article is to assess the value of a large panel of clinical and MDCT variables in patients with suspected small-bowel obstruction (SBO) for predicting urgent surgical intervention (< 72 hours), bowel ischemia, and bowel resection.

MATERIALS AND METHODS

MDCT studies performed at admission for 179 nonconsecutive adults (mean age, 55.8 years; 86 men and 93 women) with suspected SBO were retrospectively reviewed by three board-certified radiologists. In addition to assessing individual CT features, each radiologist scored the overall likelihood of each main outcome measure using a 5-point scale. All relevant clinical and laboratory data were abstracted from electronic medical record review. Univariate and multivariate analyses were performed.

RESULTS

Among all 179 patients with suspected SBO, 56 (31.3%) underwent surgical intervention within 72 hours, 10 (5.6%) had ischemia at surgery, and nine (5.0%) required small-bowel resection. On univariate analysis, multiple CT findings were highly significant (p < 0.01) for predicting the main surgical outcomes, including degree of obstruction, 5-point radiology likelihood scores, and the presence of a transition point, closed loop, and mesenteric congestion. None of the objective clinical or laboratory variables (including serum lactate level) reached this level of significance. At multivariate analysis, forward stepwise logistic regression with 0.05 significance level cutoff included both degree of obstruction (p < 0.001) and closed loop (p < 0.01), with the presence of a transition point showing a trend toward significance (p = 0.081).

CONCLUSION

A number of findings at abdominal MDCT are associated with the need for surgery and other important surgical outcomes in patients with suspected SBO. Overall radiologist impression of need for surgical intervention was a better predictor than any clinical or laboratory parameter.

Determination of therapeutic strategy for adhesive small bowel obstruction using water-soluble contrast agents: An audit of 776 cases in a single center

BACKGROUND

Several studies have investigated the diagnostic and therapeutic role of water-soluble contrast agents in adhesive small bowel obstruction, but there is no clear diagnostic classification for the determination of therapeutic strategy. The aim of this study was to clarify the clinical value of classification using water-soluble contrast agents in patients with adhesive small bowel obstruction.

METHODS

Between January 2009 and December 2015, 776 consecutive patients with adhesive small bowel obstruction were managed initially with water-soluble contrast agents and were included in the study. Abdominal x-rays were taken 5 hours after administration of 100 mL water-soluble contrast agents and classified into 4 types. The medical records of the patients with adhesive small bowel obstruction were analyzed retrospectively and divided into 2 groups of patients with complete obstruction (ie, the absence of contrast agent in the colon) with (type I) or without (type II) a detectable point of obstruction and a group with an incomplete obstruction (ie, the presence of contrast agent in the colon) with (type IIIA) or without (type IIIB) dilated small intestine.

RESULTS

Types I, II, IIIA, and IIIB were identified in 27, 90, 358, and 301 patients, respectively. The overall operative rate was 16.6%. In the patients treated conservatively (types IIIA and IIIB), 647 patients (98.2%) were treated successfully without operative intervention. The operative rate was 3.4% (n = 12/358) in type IIIA vs 0% (n = 0/301) in the type IIIB group (P = .001). Compared with type IIIA, type IIIB was associated with earlier initiation of oral intake (2.1 vs 2.6 days, P < .001) and a lesser hospital stays (9 vs 11 days, P < .001).

CONCLUSION

This new classification using water-soluble contrast agents is a simple and useful diagnostic method for the determination of therapeutic strategy for adhesive small bowel obstruction.

Pre-operative CT predictors associated with 30-day adverse events in patients with appendiceal inflammatory masses who underwent immediate appendectomies

PURPOSE

To retrospectively evaluate pre-operative CT predictors that are associated with 30-day adverse events in patients who underwent immediate appendectomies for appendiceal inflammatory masses.

METHODS

This retrospective study was approved by our institutional review board, and the requirement for informed consent was waived. One hundred forty-four consecutive patients who underwent immediate appendectomies and were diagnosed with appendiceal inflammatory masses by pre-operative CT from January 2005 to December 2013 at a tertiary hospital were included. The main outcome measure was 30-day adverse events. Patient demographics and data for inflammatory markers including leukocyte counts, segmented neutrophils, and C-reactive protein levels were collected by a single radiologist. Pre- and post-operative CT findings were evaluated for features of appendiceal inflammatory masses, associated findings, and post-operative adverse events by two radiologists in a blinded fashion with consensus to assess surgical and pathologic results, post-operative outcomes, and original CT interpretations. Appendiceal inflammatory masses were defined as complicated appendicitis with a phlegmon or an abscess that was identified on pre-operative CT exam. Factors associated with 30-day adverse events were assessed using logistic regression analysis.

RESULTS

A total of 22 (15%) of the 144 patients (mean age [±SD] 44.6 ± 22.0 years, range 3-97 years) experienced 30-day adverse events: ten intra-abdominal abscesses, three wound infections, two cases of peritonitis, two small bowel obstructions, two intra-abdominal abscesses with peritonitis, one intra-abdominal abscess with wound infection, one intra-abdominal abscess with small bowel obstruction, and one case of peritonitis with small bowel obstruction. In univariate analysis, the presence of appendicolith (odds ratio [OR] 2.49, p = 0.048) and high-grade obstruction (OR 3.79; p = 0.01) were associated with adverse events. High-grade obstruction (adjusted OR 3.05; p = 0.04) was the only independent pre-operative predictor associated with 30-day adverse events in patients with appendiceal inflammatory masses.

CONCLUSIONS

High-grade obstruction was an independent pre-operative CT predictor associated with 30-day adverse events in patients who underwent immediate appendectomies for appendiceal inflammatory masses.

COMPARISON OF COMPUTED TOMOGRAPHY AND ABDOMINAL RADIOGRAPHY FOR DETECTION OF CANINE MECHANICAL INTESTINAL OBSTRUCTION

Vomiting, often caused by mechanical intestinal obstruction, is common in dogs. Equivocal radiographic signs often necessitate repeat radiographs or additional imaging procedures. For our prospective, case-controlled, accuracy study, we hypothesized the following: (1) using computed tomography (CT), radiologists will be more sensitive and specific for detecting mechanical intestinal obstruction and recommending surgery compared to using radiographs; and (2) using measurements, radiologists will be more sensitive and specific using radiographs or CT for detecting mechanical intestinal obstruction and recommending surgery. Twenty dogs had abdominal radiographs and abdominal CT. Seventeen dogs had abdominal surgery and three dogs were not obstructed based on clinical follow-up. Confidence levels (five-point scale) of three experienced radiologists for mechanical intestinal obstruction and recommending surgery were recorded before and after making selected measurements. Eight dogs had surgically confirmed mechanical intestinal obstruction, and 12 dogs did not have obstruction. For detecting mechanical intestinal obstruction, CT was more sensitive (95.8% vs. 79.2%) and specific (80.6% vs. 69.4%) compared to radiographs, but the difference was not statistically significant. For recommending surgery, radiography was more sensitive (91.7% vs. 83.3%) and specific (83.3% vs. 72.2%) than using CT, but differences were not statistically significant. We reported objective CT measurements for predicting small mechanical intestinal obstruction. By incorporating these objective data, the diagnosis of mechanical intestinal obstruction changed in five of 120 instances (radiographs and CT). In no instance (0/120), did the objective data change the recommendation for surgery. Using CT or abdominal radiographs for the detection of canine mechanical intestinal obstruction is sensitive and specific when evaluated by experienced veterinary radiologists.

MR enterography-histology comparison in resected pediatric small bowel Crohn disease strictures: can imaging predict fibrosis?

BACKGROUND

Crohn disease is a chronic inflammatory condition that can lead to intestinal strictures. The presence of fibrosis within strictures alters optimal management but is not reliably detected by current imaging methods.

OBJECTIVE

To correlate the MRI features of surgically resected small-bowel strictures in pediatric Crohn disease with histological inflammation and fibrosis scoring.

MATERIALS AND METHODS

We included children with Crohn disease who had symptomatic small-bowel strictures requiring surgical resection and had preoperative MR enterography (MRE) within 3 months of surgery (n = 20). Two blinded radiologists reviewed MRE examinations to document stricture-related findings. A pediatric pathologist scored stricture histological specimens for fibrosis (0-4) and inflammation (0-4). MRE findings were correlated with histological data using Spearman correlation (ρ) and exact logistic regression analysis.

RESULTS

There was significant positive correlation between histological bowel wall fibrosis and inflammation in resected strictures (ρ = 0.55; P = 0.01). Confluent transmural histological fibrosis was associated with pre-stricture upstream small-bowel dilatation >3 cm at univariate (odds ratio [OR] = 51.7; 95% confidence interval [CI]: 7.6- > 999.9; P = 0.0002) and multivariate (OR = 43.4; 95% CI: 6.1- > 999.9; P = 0.0006, adjusted for age) analysis. The degree of bowel wall T2-weighted signal intensity failed to correlate with histological bowel wall fibrosis or inflammation (P-values >0.05). There were significant negative correlations between histological fibrosis score and patient age at resection (ρ = -0.48, P = 0.03), and time from diagnosis to surgery (ρ = -0.73, P = 0.0002).

CONCLUSION

Histological fibrosis and inflammation co-exist in symptomatic pediatric Crohn disease small-bowel strictures and are positively correlated. Pre-stenotic upstream small-bowel dilatation greater than 3 cm is significantly associated with confluent transmural fibrosis.

Colon cancer presented with sigmoid volvulus: A case report

INTRODUCTION

Sigmoid volvulus is the most prevalent type of colonic volvulus. Colon cancer is seen less where sigmoid volvulus is common, so it is rare to see that colon cancer is synchronous with sigmoid volvulus.

PRESENTATION OF CASE

We would like to present a case of sigmoid volvulus caused by colon cancer in a male patient aged 80 who was referred to the hospital with toxaemic shock presentation.

DISCUSSION

Sigmoid cancer can be presented as sigmoid volvulus to the emergency department. In intestinal obstruction early diagnosis is of crucial importance. Computarized tomography is a diagnosis tool that should be preferred both in the diagnosis of obstruction and in detecting its cause, localisation, degree and complications.

CONCLUSION

When surgery is performed due to the urgent colonic obstruction in colonic volvulus diagnosed patients, a colon tumour should be considered in the same column loops or in the distal colon. We believe that CT is the method that should be preferred in large-bowel obstruction suspected patients.

Review of small-bowel obstruction: the diagnosis and when to worry

This is a review of small-bowel obstruction written primarily for residents. The review focuses on radiography and computed tomography (CT) for diagnosing small-bowel obstruction and CT for determining complications. (©) RSNA, 2015.

Early diagnosis of bowel obstruction and strangulation by computed tomography in emergency department

BACKGROUND

Closed loop bowel obstruction is a specific type of mechanical obstruction with a high risk of strangulation and bowel infarction, especially in the small bowel. It is associated with a high mortality rate. Hence, it is important for emergency physicians to identify the presence of strangulation, while making the diagnosis of closed loop small bowel obstruction.

METHODS

We reported three patients with strangulated closed loop small bowel obstruction associated with severe abdominal pain, who had been treated at the emergency department. Urgent computerized tomography was performed in the patients.

RESULTS

Two patients were discharged with stable conditions, and one patient died after hemodialysis.

CONCLUSION

Urgent computerized tomography of the abdomen serves as an important diagnostic tool in view of its ability to detect the site, level and cause of obstruction along with the distinctive CT appearance of closed loop small bowel obstruction and signs of ischemia. Early definitive diagnosis will guide subsequent management and improve outcomes.

Case 205: renal stone ileus

History An 80-year-old woman presented to the on-call surgical team with a 2-day history of abdominal distention and vomiting. Clinical examination revealed a distended tympanic abdomen with generalized tenderness but no evidence of peritoneal signs at physical examination. Relevant surgical history included previous intervention for renal stones, cholecystectomy, and cardiovascular and respiratory comorbidities. Abdominal radiography was performed in the emergency department, and computed tomography (CT) was performed based on the radiographic findings.

Role of multislice computed tomography in evaluation and management of intestinal obstruction

The aims and objectives of this study were: i) to evaluate the efficacy of computed tomography (CT) imaging in diagnosing the presence, level, degree, and cause of intestinal obstruction, and the role of CT in detecting presence of complications; ii) to assess impact of CT in decision making and management (surgical/conservative); iii) to correlate CT findings with intra operative findings whenever possible. A prospective study of 40 patients presented in outpatient/emergency department with features suggestive of intestinal obstruction. Multislice contrast enhanced computed tomography of whole abdomen was done in all patients after preliminary investigations. Whenever indicated, patients were explored. Statistical analysis was performed to determine the efficacy of multidetector computed tomography (MDCT) in diagnosing intestinal obstruction and its complications. Out of 40, 30 patients underwent exploratory laparotomy and it was found that MDCT was 85% sensitive and 70% specific in diagnosing bowel obstruction. Association between MDCT findings suggestive of obstruction and intra-operative findings turn out to be significant (P=0.003). MDCT findings were consistent with intraoperative findings in 22 out of 30 patients (73%). MDCT is sensitive and specific in determining the presence of bowel obstruction and should be recommended for patients with suspected bowel obstruction because it affects outcome in these patients.

Adult small bowel obstruction

BACKGROUND

Small bowel obstruction (SBO) is a clinical condition that is often initially diagnosed and managed in the emergency department (ED). The high rates of potential complications that are associated with an SBO make it essential for the emergency physician (EP) to make a timely and accurate diagnosis.

OBJECTIVES

The primary objective was to perform a systematic review and meta-analysis of the history, physical examination, and imaging modalities associated with the diagnosis of SBO. The secondary objectives were to identify the prevalence of SBO in prospective ED-based studies of adult abdominal pain and to apply Pauker and Kassirer's threshold approach to clinical decision-making to the diagnosis and management of SBO.

METHODS

MEDLINE, EMBASE, major emergency medicine (EM) textbooks, and the bibliographies of selected articles were scanned for studies that assessed one or more components of the history, physical examination, or diagnostic imaging modalities used for the diagnosis of SBO. The selected articles underwent a quality assessment by two of the authors using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. Data used to compile sensitivities and specificities were obtained from these studies and a meta-analysis was performed on those that examined the same historical component, physical examination technique, or diagnostic test. Separate information on the prevalence and management of SBO was used in conjunction with the meta-analysis findings of computed tomography (CT) to determine the test and treatment threshold.

RESULTS

The prevalence of SBO in the ED was determined to be approximately 2% of all patients who present with abdominal pain. Having a previous history of abdominal surgery, constipation, abnormal bowel sounds, and/or abdominal distention on examination were the best history and physical examination predictors of SBO. X-ray was determined to be the least useful imaging modality for the diagnosis of SBO, with a pooled positive likelihood ratio (+LR) of 1.64 (95% confidence interval [CI] = 1.07 to 2.52). On the other hand, CT and magnetic resonance imaging (MRI) were both quite accurate in diagnosing SBO with +LRs of 3.6 (5- to 10-mm slices, 95% CI = 2.3 to 5.4) and 6.77 (95% CI = 2.13 to 21.55), respectively. Although limited to only a select number of studies, the use of ultrasound (US) was determined to be superior to all other imaging modalities, with a +LR of 14.1 (95% CI = 3.57 to 55.66) and a negative likelihood ratio (-LR) of 0.13 (95% CI = 0.08 to 0.20) for formal scans and a +LR of 9.55 (95% CI = 2.16 to 42.21) and a -LR of 0.04 (95% CI = 0.01 to 0.13) for beside scans. Using the CT results of the meta-analysis for the 5- to 10-mm slice subgroup as well as information on intravenous (IV) contrast reactions and nasogastric (NG) intubation management, the pretest probability threshold for further testing was determined to be 1.5%, and the pretest probability threshold for beginning treatment was determined to be 20.7%.

CONCLUSIONS

The potentially useful aspects of the history and physical examination were limited to a history of abdominal surgery, constipation, and the clinical examination findings of abnormal bowel sounds and abdominal distention. CT, MRI, and US are all adequate imaging modalities to make the diagnosis of SBO. Bedside US, which can be performed by EPs, had very good diagnostic accuracy and has the potential to play a larger role in the ED diagnosis of SBO. More ED-focused research into this area will be necessary to bring about this change.

Utility of CT in the diagnosis and management of small-bowel obstruction in children

BACKGROUND

CT is often used in the diagnosis and management of small-bowel obstruction in children.

OBJECTIVE

To determine sensitivity of CT in delineating presence, site and cause of small-bowel obstruction in children.

MATERIALS AND METHODS

We retrospectively reviewed the CT scans of 47 children with surgically proven small-bowel obstruction. We noted any findings of obstruction and the site and cause of obstruction. Presence, absence or equivocal findings of bowel obstruction on abdominal radiographs performed prior to CT were also noted. We reviewed patient charts for clinical details and surgical findings, including bowel resection. Statistical analysis was performed using Fisher exact test to determine which CT findings might predict bowel resection.

RESULTS

CT correctly diagnosed small-bowel obstruction in 43/47 (91.5%) cases. CT correctly indicated site of obstruction in 37/47 (78.7%) cases and cause of obstruction in 32/47 (68.1%) cases. Small-bowel feces sign was significantly associated with bowel resection at surgery (P = 0.0091). No other CT finding was predictive of bowel resection. Out of 41 children who had abdominal radiographs before CT, 29 (70.7%) showed unequivocal obstruction, six (14.6%) showed equivocal findings and six (14.6%) were unremarkable.

CONCLUSION

CT is highly sensitive in diagnosing small-bowel obstruction in children and is helpful in determining the presence of small-bowel obstruction in many clinically suspected cases with equivocal or normal plain radiographs. CT also helps to determine the site and cause of the obstruction with good sensitivity.

Development of the Paris definition of early Crohn's disease for disease-modification trials: results of an international expert opinion process

We report the findings and outputs of an international expert opinion process to develop a definition of early Crohn's disease (CD) that could be used in future disease-modification trials. Nineteen experts on inflammatory bowel diseases held an international expert opinion meeting to discuss and agree on a definition for early CD to be used in disease-modification trials. The process included literature searches for the relevant basic-science and clinical evidence. A published preliminary definition of early CD was used as the basis for development of a proposed definition that was discussed at the expert opinion meeting. The participants then derived a final definition, based on best current knowledge, that it is hoped will be of practical use in disease-modification trials in CD.

A rare cause of gastrointestinal phytobezoars: diospyros lotus

Aim

Diospyros Lotus (“Wild Date Palm of Trabzon or Persimmon”), which has been proven to cause phytobezoars, is a widely consumed fruit in the Black Sea and Northeast Anatolia regions of Turkey. The aim of the present study was to investigate the effects of Diospyros Lotus together with other predisposing factors, on the development of gastrointestinal phytobezoars and to discuss the treatment results in comparison to the literature.

Material and method

The records of 13 patients, who had been admitted to the General Surgery Clinic of Düzce Atatürk State Hospital between August 2008 and August 2011, were retrospectively reviewed. Demographic characteristics, predisposing factors, clinical and radiological findings, diagnostic and therapeutic methods, and the outcomes of the patients were recorded from the patient files. Written informed consent was obtained from each patient for publication of this research article and accompanying images.

Results

All the patients had a history of consuming Diospyros Lotus. Of the patients, 30,7% had a history of previous gastric surgery, 30,7% had diabetes mellitus and 23% had dental implants. None of the patients had hypothyroidism, which is another predisposing factor for phytobezoars.

The phytobezoars were located in the stomach alone in 23% of the patients, whereas 15,3% was detected in the jejunum and stomach, 15,3% was detected in the jejunum alone, and 46,1% was detected in the ileum alone. All patients were treated with surgery, and there were no deaths.

Conclusion

Gastric phytobezoars are rare. Preventive measures have particular importance in the management of this condition, which is difficult to treat. For this purpose, excessive consumption of herbal nutrients containing a high amount of indigestible fibers such as Diospyros Lotus should be avoided in patients with a history of gastrointestinal surgery or poor oral and dental health.

CT diagnosis of the nature of bowel obstruction: morphological evaluation of the transition point

PURPOSE

This study evaluated transition-point morphology for defining the nature of bowel obstructions.

MATERIALS AND METHODS

Computed tomography (CT) examinations of 95 patients affected by severe bowel obstruction (23 neoplastic, 72 nonneoplastic) were retrospectively reviewed.

RESULTS

The transition point was identified in 89 patients (94%); morphology in relation to the proximal loop was concave in 64 cases (68%), linear in five (5%) and convex in 20 (21%). Concave transition-point morphology was indicative of a nonneoplastic condition, with sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy values of 89%, 100%, 100%, 74% and 92%, respectively. A linear shape had almost identical incidence among neoplastic (60%) and nonneoplastic (40%) conditions. A convex appearance correlated with neoplastic disease with sensitivity, specificity, PPV, NPV and diagnostic accuracy values of 87%, 100%, 100%, 96% and 97%, respectively.

CONCLUSIONS

In the case of bowel obstruction, transitionpoint detection indicates the obstruction site, whereas its morphological evaluation can contribute to defining the nature of the obstruction. A concave morphology indicates a nonneoplastic condition with a high probability; a convex morphology correlates with neoplastic disease, whereas linearity is not significant.

Imaging of acute right lower quadrant abdominal pain: differential diagnoses beyond appendicitis

Evaluation of acute right lower quadrant pain remains a common and challenging clinical scenario for emergency medicine physicians due to frequent nonspecific signs, symptoms, and physical examination findings. Therefore, imaging has evolved to play a pivotal role in the emergency setting. While appendicitis is a common cause for acute pain, there are numerous other important differential considerations with which the radiologist must be aware. The purpose of this review is to list an anatomy-based, encompassing differential diagnosis in addition to acute appendicitis for right lower quadrant pain; demonstrate the key imaging findings of numerous differential considerations; and describe helpful imaging and clinical features useful in narrowing the differential diagnosis.

Current management of small bowel obstruction

SBO is a common disease with multiple causes. The most significant advances over the past several years have involved, first, decision-making techniques to promptly and accurately identify patients who will require exploration, and, second, the increasing use of laparoscopic techniques. "Complete" bowel obstruction is becoming an outdated term, as treatment algorithms use predictive models and oral contrast challenges to select patients for operation without recourse to the notion of "complete obstruction." Laparoscopic techniques are gaining acceptance as a primary modality in the treatment of SBO. Appropriate patient selection is necessary for success, but successful laparoscopic SBO management can reduce postoperative pain, minimize hospital stay, and may lead to fewer adhesions, possibly preventing further adhesive SBO. Strangulation obstruction is the major cause of morbidity and mortality in SBO. Although unrecognized strangulation obstructions remain, their incidence is decreasing with the new protocols in development. Future efforts should focus on incorporating predictive models into management with the goal of eliminating unrecognized strangulation obstructions. Further refinement of the predictive models incorporating outcomes of oral contrast challenges and molecular biomarker data may allow surgeons to reach this goal. In addition, the benefit of the elimination of interpractitioner variability conferred by standardized protocols will in itself improve patient outcomes.

Value of "protruding lips" sign in malignant bowel obstructions

OBJECTIVE

This study aims to evaluate the diagnostic accuracy of a new CT sign in order to define or exclude a malignant aetiology of bowel obstruction.

MATERIALS AND METHODS

CT scans of 137 patients affected by bowel obstruction were reviewed. Colonic obstruction occurred in 47 (34%) cases, small bowel obstruction in 90 (66%). Neoplastic aetiology was found in 42 cases (31%), while in the remaining 95 (69%) obstruction was caused by non-neoplastic conditions. Definitive diagnosis was surgically confirmed in all patients. CT images were evaluated searching for bowel obstruction's signs and for the presence of the "protruding lips" sign on the proximal surface of stenosis, which is represented by the evidence of a protrusion within the dilated loop.

RESULTS

The sign was found in 31 (23%) cases, all of neoplastic origin. When malignant obstruction was diagnosed, sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy values of the described sign were 74%, 100%, 100%, 90% and 92%, respectively.

CONCLUSIONS

The "protruding lips" sign represents an alteration to be searched when bowel obstruction is diagnosed by CT examination. Its evidence correlates to a malignant condition with a 100% probability and when it is not found, the probability of a non-neoplastic condition is 90%.

The role of plain radiographs in patients with acute abdominal pain at the ED

OBJECTIVE

The purpose of this study was to evaluate the added value of plain radiographs on top of clinical assessment in unselected patients presenting with acute abdominal pain at the emergency department (ED).

METHODS

In a multicenter prospective trial, patients with abdominal pain more than 2 hours and less than 5 days presented at the ED were evaluated clinically, and a diagnosis was made by the treating physician. Subsequently, all patients underwent supine abdominal and upright chest radiographs, after which the diagnosis was reassessed by the treating physician. A final (reference) diagnosis was assigned by an expert panel. The number of changes in the primary diagnosis, as well as the accuracy of these changes, was calculated. Changes in the level of confidence were evaluated for unchanged diagnoses.

RESULTS

Between March 2005 and November 2006, 1021 patients, 55% female, mean age 47 years (range, 19-94 years), were included. In 117 of 1021 patients, the diagnosis changed after plain radiographs, and this change was correct in 39 patients (22% of changed diagnoses and 4% of total study population). Overall, the clinical diagnosis was correct in 502 (49%) patients. The diagnosis after evaluation of the radiographs was correct in 514 (50%) patients, a nonsignificant difference (P = .14). In 65% of patients with unchanged diagnosis before and after plain radiography, the level of confidence of that diagnosis did not change either.

CONCLUSION

The added value of plain radiographs is too limited to advocate their routine use in the diagnostic workup of patients with acute abdominal pain, because few diagnoses change and the level of confidence were mostly not affected.

CT enterography

Conventional radiologic and endoscopic evaluations of the small bowel are often limited by the length, caliber, and motility of the small bowel loops. The development of new multidetector-row CT scanners, with faster scan times and isotropic spatial resolution, allows high-resolution multiphasic and multiplanar assessment of the bowel, bowel wall, and lumen. CT Enterography (CTE) is a variant of routine abdominal scanning, geared toward more sustained bowel filling with oral contrast material, and the use of multiplanar images, that can enhance gastrointestinal (GI) tract imaging. This article examines the techniques and clinical applications of CTE in comparison with CT enteroclysis, focusing on Crohn disease, obscure GI bleeding, GI tumors, acute abdominal pain, and bowel obstruction.

Intestinal duplication in an adult patient diagnosed by multidetector computed tomography enteroclysis: report of a case

This study reports a case of small-bowel duplication, a rare congenital malformation, in an adult with abdominal pain and sub-obstruction signs. CT enteroclysis allowed the diagnosis that conventional imaging failed to demonstrate and it confirmed itself the most accurate exam in small-bowel disease diagnosis. This is the first report of a small-bowel duplication diagnosed by CT enteroclysis.

Meckel diverticulum causing small bowel obstruction

A 62-year-old man was admitted with generalised abdominal pain, constipation and vomiting. His abdomen was markedly distended and tender on general examination with signs of local peritonism in the left iliac fossa. He was initially diagnosed with likely acute diverticulitis and treated conservatively. A CT scan the next day showed fluid filled, dilated small bowel loops consistent with small bowel obstruction and there was a suggestion of an abscess in the left iliac fossa region. An urgent laparotomy was performed, which identified a perforated Meckel diverticulum.