Small bowel obstruction: what to look for

Unusual causes of Small bowel obstruction: a review of the literature and revisited cross-sectional imaging checklist

Intestinal obstruction is a common surgical emergency with high morbidity and mortality. Patients presenting with features of small bowel obstruction need urgent evaluation to avoid complications such as bowel gangrene, perforation, or peritonitis. Imaging is necessary in most cases of suspected bowel obstruction, to take an appropriate decision, for apt patient management. Among the common causes of small bowel obstruction, adhesions, external herniae, malignancies, and Crohn's disease top the chart. Imaging helps in determining the presence of obstruction, the severity of obstruction, transition point, cause of obstruction, and associated complications such as strangulation, bowel gangrene, and peritonitis. This review is based on the cases with unusual causes of bowel obstruction encountered during our routine practice and also on the extensive literature search through the standard textbooks and electronic databases. Through this review we want our readers to have sound knowledge of the imaging characteristics of the uncommon yet important causes of bowel obstruction. We have also revisited and structured a checklist to simplify the approach while reporting a suspected case of small bowel obstruction. Imaging plays a key role in the diagnosis of small bowel obstruction and in determining the cause and associated complications. Apart from the common causes of small bowel obstruction, we should also be aware of the uncommon causes of small bowel obstruction and their imaging characteristics to make an accurate diagnosis and for apt patient management.

Development and validation of deep learning models for bowel obstruction on plain abdominal radiograph

OBJECTIVE

Artificial intelligence (AI) could help medical practitioners in analyzing radiological images to determine the presence and site of bowel obstruction. This retrospective diagnostic study proposed a series of deep learning (DL) models for diagnosing bowel obstruction on abdominal radiograph.

METHODS

A total of 2082 upright plain abdominal radiographs were retrospectively collected from four hospitals. The images were labeled as normal, small bowel obstruction and large bowel obstruction by three senior radiologists based on comprehensive examinations and interventions within 48 hours after admission. Gradient-weighted class activation mapping was used to visualize the inferential explanation.

RESULTS

In the validation set, the Xception-backboned model achieved the highest accuracy (0.863), surpassing the VGG16 (0.847) and ResNet models (0.836). In the test set, the Xception model (accuracy: 0.807) outperformed other models and a junior radiologist (0.780) but not a senior radiologist (0.840). In the AI-aided diagnostic framework, the junior and senior radiologists made their judgements while aware of the Xception model predictions. Their accuracy significantly improved to 0.887 and 0.913, respectively.

CONCLUSIONS

We developed and validated DL-based computer vision models for diagnosing bowel obstruction on plain abdominal radiograph. DL-based computer-aided diagnostic systems could reduce medical practitioners' workloads and improve diagnostic accuracy.

Evaluation of Multidetector Computed Tomography in the Diagnosis of Intestinal Obstruction

Background Acute intestinal obstruction is a commonly encountered surgical emergency that is prevalent worldwide and has substantial morbidity and fatality rates. Therefore, swift and precise diagnosis is essential. While mortality rates in urban areas have declined due to timely medical intervention following early detection, the situation contrasts starkly in rural areas. Delays in presentations often lead to complications because of hesitancy toward surgery, economic challenges, and limited access to healthcare information. Therefore, this study aimed to evaluate how well multidetector computed tomography (MDCT) can help determine the site, cause, and level of intestinal obstruction compared to what the surgeons confirmed intraoperatively. Methodology A prospective study involving 101 patients was conducted at a tertiary care center in western Maharashtra from July 2022 to July 2024. The emergency department referred patients with clinical symptoms such as nausea and vomiting, abdominal distension, abdominal pain, inability to pass flatus, constipation, or diarrhea, which are commonly seen with intestinal obstruction. The study involved all patients who underwent a contrast-enhanced MDCT scan using both intravenous and oral contrast agents. We selected patients from both genders, regardless of their age; however, considerations were taken to include characteristics convenient and relevant to the study. Patients with abnormal serum creatinine levels or allergies to contrast were excluded from the study. We conducted CT examinations, noting findings such as the transition point between the dilated and collapsed loops, mesenteric fat stranding, and intestinal dilatation. An experienced radiologist made the final report, and the operating surgeons' notes on laparoscopy or open surgery for the same patient were reviewed to understand the operative findings. Results MDCT scans had high diagnostic accuracy for small and large bowel obstruction. Of the 101 patients, the mean age was 43.7 years. There were 70 (69.30%) males and 31 (30.69%) females. Sensitivity was 100%, specificity was 98.1%, positive predictive value was 83.7%, and negative predictive value was 100%. Conclusions MDCT demonstrated high sensitivity and specificity for diagnosing and determining the underlying cause of intestinal obstruction. It identified the location of the obstruction and discerned whether it originated from intrinsic, extrinsic, or intraluminal factors.

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.

Towards an EKG for SBO: A Neural Network for Detection and Characterization of Bowel Obstruction on CT

A neural network was developed to detect and characterize bowel obstruction, a common cause of acute abdominal pain. In this retrospective study, 202 CT scans of 165 patients with bowel obstruction from March to June 2022 were included and partitioned into training and test data sets. A multi-channel neural network was trained to segment the gastrointestinal tract, and to predict the diameter and the longitudinal position ("longitude") along the gastrointestinal tract using a novel embedding. Its performance was compared to manual segmentations using the Dice score, and to manual measurements of the diameter and longitude using intraclass correlation coefficients (ICC). ROC curves as well as sensitivity and specificity were calculated for diameters above a clinical threshold for obstruction, and for longitudes corresponding to small bowel. In the test data set, Dice score for segmentation of the gastrointestinal tract was 78 ± 8%. ICC between measured and predicted diameters was 0.72, indicating moderate agreement. ICC between measured and predicted longitude was 0.85, indicating good agreement. AUROC was 0.90 for detection of dilated bowel, and was 0.95 and 0.90 for differentiation of the proximal and distal gastrointestinal tract respectively. Overall sensitivity and specificity for dilated small bowel were 0.83 and 0.90. Since obstruction is diagnosed based on the diameter and longitude of the bowel, this neural network and embedding may enable detection and characterization of this important disease on CT.

[Postoperative Imaging Findings of Colorectal Surgery: A Pictorial Essay]

Postoperative colorectal imaging studies play an important role in the detection of surgical complications and disease recurrence. In this pictorial essay, we briefly describe methods of surgery, imaging findings of their early and late complications, and postsurgical recurrence of cancer and inflammatory bowel disease.

Bowel Emergencies in Patients With Cancer

Cancer is the second most common cause of death worldwide. Bowel emergencies in patients with cancer are becoming increasingly more prevalent due to advances in cancer therapy and longer overall patient survival. When these patients present acutely, they are often frail and may have pre-existing co-morbidities. This article discusses the imaging features of bowel emergencies commonly encountered in oncological patients in clinical practice. These include chemotherapy related colitis, neutropenia enterocolitis and typhlitis, toxic megacolon, bowel perforation, malignant bowel obstruction and gastrointestinal haemorrhage. The radiologist plays a key role in identifying these oncological emergencies and guiding further management.

CT prognostic signs of postoperative complications in emergency surgery for acute obstructive colonic cancer

PURPOSE

To identify CT prognostic signs of poor outcomes in acute obstructive colonic cancer (AOCC).

METHODS

Demographic, clinical, laboratory, radiological and surgical data of 65 consecutive patients with AOCC who underwent emergency surgery were analyzed. CT exams were reviewed to assess diameters of cecum, ascending, transverse, descending, and sigmoid proximal to the tumor; colon segments' CD/L1-VD ratios, continence of the ileocecal valve, small bowel overdistension, presence of small bowel feces sign and cecal pneumatosis. Post Operative complications (PO), according to the Clavien-Dindo classification, were analyzed.

RESULTS

Gender, age and location of the tumor were not predictive factors of complications. Among laboratory exams, CRP was the most important predictive value of PO (OR 8.23). A cecum distension ≥ 9 cm represented the critical diameter beyond which perforation and cecal necrosis were found at surgery. Cecal pneumatosis at CT was correlated with cecal necrosis at surgery in < 50% of patients. Pre-operative transverse colon CD/L1-VD ratio ≥ 1.43 and descending colon CD/L1-VD ratio ≥ 1.31 were associated with the development of PO (grade ≥ III-V). PO (grade ≥ III-V) occurred in 18/65 patients.

CONCLUSION

Postoperative complications in emergency surgery of AOCC were not related to the age, sex and tumor's location. Preoperative PCR values (≥ 2.17) predict the development of postoperative complications. CT resulted a valid diagnostic tool to identify patients at higher risk of complications: a CD/L1-VD ratios with cut-off values of 1.43 (transverse) and 1.31 (descending) predicted major complications (grade ≥ III-V) and a cecum distension ≥ 9 cm represented the critical diameter beyond which perforation occurred in > 84% of patients.

Up-to-date review into the evolving world of bariatric interventions: a guide for radiologists

Obesity is a worldwide health concern leading to several chronic health problems and comorbidities. Its treatment requires a multidisciplinary approach where lifestyle changes are fundamental. Additionally, in the past decade, the use of different surgical procedures of various levels of complexity has grown, with the objective of reducing the gastric capacity, creating diversions, or a combination of both. The aim of this article is to review and illustrate the major types of bariatric surgical techniques, their normal post-surgical anatomy, and the possible associated complications, to aid the radiologist in their assessment and timely diagnosis.

Imaging of abdominopelvic oncologic emergencies

With advancements in cancer treatment, the survival rates for many malignancies have increased. However, both the primary tumors and the treatments themselves can give rise to various complications. Acute symptoms in oncology patients require prompt attention. Abdominopelvic oncologic emergencies can be classified into four distinct categories: vascular, bowel, hepatopancreatobiliary, and bone-related complications. Radiologists need to be familiar with these complications to ensure timely diagnosis, which ultimately enhances patient outcomes.

Evaluation of Abdominal Emergencies

Early primary assessment and abdominal examination can often be enough to triage the patient with abdominal pain into those with less severe underlying pathologic condition from those with more acute findings. A focused history of the patient can then allow the clinician to develop their differential diagnosis. Once the differential diagnoses are determined, diagnostic imaging and laboratory findings can help confirm the diagnosis and allow for expeditious treatment and intervention.

Accurately evaluating for a small bowel obstruction using an abdominal radiograph, by a new method: The Bowel-Spine Ratio

INTRODUCTION

A well-established method does not exist to rule out a small bowel obstruction using an abdominal xray series with significant accuracy. The hypothesis of the study is that the ratio of an average small bowel diameter to lumbar spine diameter over 0.5 is most likely a small bowel obstruction.

METHODS

An x-ray abdominal series measurement technique was applied to 41 subjects with a chief complaint of "abdominal pain" as part of a randomized retrospective case review to predict an obstruction v. non obstruction. A total number of 81 abdominal pain subjects with a mean age of 46.7 years were selected with 40 excluded due to normal small bowel gas pattern. The subject's medical information was unknown to the authors when reading their images. The measurement technique involved averaging the largest and smallest small bowel short axis diameters with comparison to the lowest clearly visible lumbar body width. The subjects' medical course as described in the medical chart or subsequent computed tomography scans were used as the referencing standard to determine presence of obstruction vs non-obstruction.

RESULTS

This method, called the Bowel-Spine Ratio (BSR), resulted in a sensitivity of 0.882 (0.622-0.979; 95% CI), specificity of 0.957 (0.760-0.998; 95% CI), accuracy of 94.7% (80.9%-99.1%; 95% CI) and a positive likelihood ratio of 21 for predicting a small bowel obstruction.

CONCLUSION

The abdominal series Bowel-Spine Ratio is a simple yet effective technique to screen for a small bowel obstruction using limited resources and to avoid unnecessary computed tomography scans with the potential to reduce health care costs.

IMPLICATIONS FOR PRACTICE

Clinicians could have increased confidence in utilizing abdominal radiographs to evaluate for small bowel obstruction.

Visual Image Annotation for Bowel Obstruction: Repeatability and Agreement with Manual Annotation and Neural Networks

Bowel obstruction is a common cause of acute abdominal pain. The development of algorithms for automated detection and characterization of bowel obstruction on CT has been limited by the effort required for manual annotation. Visual image annotation with an eye tracking device may mitigate that limitation. The purpose of this study is to assess the agreement between visual and manual annotations for bowel segmentation and diameter measurement, and to assess agreement with convolutional neural networks (CNNs) trained using that data. Sixty CT scans of 50 patients with bowel obstruction from March to June 2022 were retrospectively included and partitioned into training and test data sets. An eye tracking device was used to record 3-dimensional coordinates within the scans, while a radiologist cast their gaze at the centerline of the bowel, and adjusted the size of a superimposed ROI to approximate the diameter of the bowel. For each scan, 59.4 ± 15.1 segments, 847.9 ± 228.1 gaze locations, and 5.8 ± 1.2 m of bowel were recorded. 2d and 3d CNNs were trained using this data to predict bowel segmentation and diameter maps from the CT scans. For comparisons between two repetitions of visual annotation, CNN predictions, and manual annotations, Dice scores for bowel segmentation ranged from 0.69 ± 0.17 to 0.81 ± 0.04 and intraclass correlations [95% CI] for diameter measurement ranged from 0.672 [0.490-0.782] to 0.940 [0.933-0.947]. Thus, visual image annotation is a promising technique for training CNNs to perform bowel segmentation and diameter measurement in CT scans of patients with bowel obstruction.

Imaging of Gastrointestinal Tract Ailments

Gastrointestinal (GI) disorders comprise a diverse range of conditions that can significantly reduce the quality of life and can even be life-threatening in serious cases. The development of accurate and rapid detection approaches is of essential importance for early diagnosis and timely management of GI diseases. This review mainly focuses on the imaging of several representative gastrointestinal ailments, such as inflammatory bowel disease, tumors, appendicitis, Meckel's diverticulum, and others. Various imaging modalities commonly used for the gastrointestinal tract, including magnetic resonance imaging (MRI), positron emission tomography (PET) and single photon emission computed tomography (SPECT), and photoacoustic tomography (PAT) and multimodal imaging with mode overlap are summarized. These achievements in single and multimodal imaging provide useful guidance for improved diagnosis, staging, and treatment of the corresponding gastrointestinal diseases. The review evaluates the strengths and weaknesses of different imaging techniques and summarizes the development of imaging techniques used for diagnosing gastrointestinal ailments.

Role of artificial intelligence in oncologic emergencies: a narrative review

Oncologic emergencies are a wide spectrum of oncologic conditions caused directly by malignancies or their treatment. Oncologic emergencies may be classified according to the underlying physiopathology in metabolic, hematologic, and structural conditions. In the latter, radiologists have a pivotal role, through an accurate diagnosis useful to provide optimal patient care. Structural conditions may involve the central nervous system, thorax, or abdomen, and emergency radiologists have to know the characteristics imaging findings of each one of them. The number of oncologic emergencies is growing due to the increased incidence of malignancies in the general population and also to the improved survival of these patients thanks to the advances in cancer treatment. Artificial intelligence (AI) could be a solution to assist emergency radiologists with this rapidly increasing workload. To our knowledge, AI applications in the setting of the oncologic emergency are mostly underexplored, probably due to the relatively low number of oncologic emergencies and the difficulty in training algorithms. However, cancer emergencies are defined by the cause and not by a specific pattern of radiological symptoms and signs. Therefore, it can be expected that AI algorithms developed for the detection of these emergencies in the non-oncological field can be transferred to the clinical setting of oncologic emergency. In this review, a craniocaudal approach was followed and central nervous system, thoracic, and abdominal oncologic emergencies have been addressed regarding the AI applications reported in literature. Among the central nervous system emergencies, AI applications have been reported for brain herniation and spinal cord compression. In the thoracic district the addressed emergencies were pulmonary embolism, cardiac tamponade and pneumothorax. Pneumothorax was the most frequently described application for AI, to improve sensibility and to reduce the time-to-diagnosis. Finally, regarding abdominal emergencies, AI applications for abdominal hemorrhage, intestinal obstruction, intestinal perforation, and intestinal intussusception have been described.

Point-of-Care Abdominal Ultrasonography (POCUS) on the Way to the Right and Rapid Diagnosis

Point-of-Care ultrasound (POCUS) is based on target ultrasound that is performed wherever a patient is being treated, and by a non-radiologist directly involved in the patient’s care. It is used either for quick diagnosis or procedural guidance. Abdominal pain is one of the most common complaints in emergency departments, and POCUS can help in the differentiation of patients who need additional diagnostic tests or hospital treatment, which eventually reduces the overall costs of health care. POCUS has high sensitivity and specificity in abdominal pathology, it can be helpful in the evaluation of biliary, intestinal, and urinary tract, and it is especially used in trauma. Additionally, the gold standard for abdominal aortic aneurysm detection, follow up and screening is precisely this diagnostic procedure. Unfortunately, the quality of ultrasound examination can be affected by the experience of the physician performing it and the patient’s body weight. There is no doubt that POCUS is being increasingly recognized, but all motivated physicians should be provided with dedicated tutors and enough time for learning. This would certainly help to implement this diagnostic method as a routine in emergency and critical care departments, and significantly shorten the time until definitive diagnosis.

Point-of Care Ultrasound in Stratifying Clinically Evolving Inguinal and Femoral Hernias

BACKGROUND

Point-of-care ultrasound (POCUS) is an optimal imaging modality for the risk stratification of patients presenting to the emergency department (ED) with inguinal and femoral hernias, allowing for better evaluation of clinical presentations and guiding appropriate treatment. The lack of ultrasound classification for inguinal and femoral hernias has led to inconsistent use and often underuse of POCUS in this patient population. Several groin hernia classifications are available, but most are complex and often targeted toward surgical management.

OBJECTIVES

The objective of this study is to review the use of POCUS in the diagnosis of inguinal and femoral hernias, providing a synopsis of critical ultrasound findings in determining signs of incarceration, strangulation, and small bowel obstruction, and suggesting a simple and educative sonographic classification for inguinal or femoral hernias.

DISCUSSION

POCUS can reliably confirm the presence of groin hernias and can uniquely identify specific ultrasound findings predictive of complications, such as aperistaltic nonreducible bowel loops, free fluid in the hernia sac, and lack of color doppler in the entrapped mesentery and bowel walls. POCUS can also aid in determining the presence of small bowel obstruction by detecting dilated loops of bowel >25 mm adjacent and proximal to the hernia site.

CONCLUSIONS

In the ED, POCUS can confirm the presence of a hernia sac and identify and predict surgical emergencies, such as bowel incarceration or strangulation, which are the most important elements in the management of patients presenting with possible inguinal or femoral hernias.

CT Imaging Findings in Patients with Ovarian Cancer and Acute Abdominal Symptoms: Experience at a Tertiary Cancer Center

PURPOSE

To evaluate computed tomography (CT) findings in patients with ovarian cancer presenting to a comprehensive cancer center's urgent care unit with acute abdominal symptoms.

METHODS

This retrospective study included consecutive patients with ovarian cancer who underwent abdominal CT at a comprehensive cancer center's urgent care unit between January 1, 2018, and January 14, 2020, due to acute abdominal symptoms. Two abdominal radiologists reviewed the abdominal CT reports, categorizing imaging findings as follows: (a) no new or acute finding, (b) new or increased bowel or gastric obstruction, (c) new or increased ascites, (d) new or increased peritoneal carcinomatosis, (e) new or increased nonperitoneal metastases, (f) new inflammatory or infectious changes, (g) new or increased hydronephrosis, (h) new or increased biliary dilatation, (i) new vascular complications, or (j) new bowel perforation.

RESULTS

A total of 200 patients (mean age, 59 years; range, 22-87) underwent a total of 259 abdominal CT scans, of which 217/259 (83.8%) scans were found to have new or increased findings. A total of 115/259 (44.4%) scans had only one finding while 102/259 (39.4%) scans had 2 or more findings. Altogether, 382 new or increased findings were detected: findings were most commonly related to bowel or gastric obstruction (92/382, 24.1%) with small bowel obstruction being the most common finding (80/382, 20.9%); ascites (78/382, 20.4%); peritoneal carcinomatosis (62/382, 16.2%); and nonperitoneal metastases (62/382, 16.2%). Inflammatory or infectious findings accounted for 30/382 (7.9%) findings.

CONCLUSION

Most patients with ovarian cancer presenting with acute abdominal had relevant positive findings on abdominal CT, with small bowel obstruction being the most common finding.

Preoperative prediction of inadvertent enterotomy during adhesive small bowel obstruction surgery using combination of CT features

OBJECTIVES

The purpose of this study was to identify the preoperative CT features that are associated with inadvertent enterotomy (IE) during adhesive small bowel obstruction (ASBO) surgery.

METHODS

From January 2015 to December 2019, all patients with ASBO who underwent an abdominal CT were reviewed. Abdominal CT were retrospectively reviewed by two radiologists with a consensus read in case of disagreement. IE during ASBO surgery was retrospectively recorded. Univariate and multivariate analyses of CT features associated with IE were performed and a simple CT score was built to stratify the risk of IE. This score was validated in an independent retrospective cohort. Abdominal CT of the validation cohort was reviewed by a third independent reader.

RESULTS

Among the 368 patients with ASBO during the study period, 169 were surgically treated, including 129 ASBO for single adhesive band and 40 for matted adhesions. Among these, there were 47 IE. By multivariate analysis, angulation of the transitional zone (OR = 4.19, 95% CI [1.10-18.09]), diffuse intestinal adhesions (OR = 4.87, 95% CI [1.37-19.76]), a fat notch sign (OR = 0.32, 95% CI [0.12-0.85]), and mesenteric haziness (OR = 0.13, 95% CI [0.03-0.48]) were independently associated with inadvertent enterotomy occurrence. The simple CT score built to stratify risk of IE displayed an AUC of 0.85 (95% CI [0.80-0.90]) in the study sample and 0.88 (95% CI [0.80-0.96]) in the validation cohort.

CONCLUSION

A simple preoperative CT score is able to inform the surgeon about a high risk of IE and therefore influence the surgical procedure.

KEY POINTS

• In this retrospective study of 169 patients undergoing abdominal surgery for adhesive small bowel obstruction, 47 (28%) inadvertent enterotomy occurred. • A simple preoperative CT score enables accurate stratification of inadvertent enterotomy risk (area under the curve 0.85). • By multivariable analysis, diffuse intestinal adhesions and angulation of the transitional zone were predictive of inadvertent enterotomy occurrence.

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.

Protective Effects of Hydrogen-Rich Saline on Experimental Intestinal Volvulus in Rats

BACKGROUND

Intestinal volvulus can cause morbidity and mortality. Surgical reduction, on the other hand, could result in ischemia-reperfusion (I/R) injury. Hydrogen rich saline solution (HRSS neutralizes free radicals in the body. This study aimed to investigate the effects of HRSS in I/R injury in experimental intestinal volvulus in rats.

METHODS

Thirty rats were randomly allocated into 5 groups. All procedures were done under general anesthesia and sterile conditions in each animal. Five ml/kg of saline and HRSS were administered intraperitoneally (ip) in Sham (Group 1) and HRSS (Group 2) groups, respectively. Groups 3, 4, and 5 constituted the study groups in which volvulus was created in a 5-cm- long ileal segment 2 cm proximal to the ileocecal valve. After 2 hours the volvuli were reduced and following 2 hours of reperfusion, these segments were removed. In volvulus-I/R group (Group 3) no additional procedure was done. HRSS was administered shortly before reperfusion (reduction of the volvulus) in Treatment I (Group 4) and 1 h before experimental volvulus in Treatment II (Group 5) groups. Blood and intestinal tissue samples were obtained from all rats at the 4th hour. Both tissue and blood total oxidant (TOS) and antioxidant status (TAS) levels were determined and tissue histomorphologies were studied. Oxidative stress indices (TOS ÷ TAS) (OSI) were calculated.

RESULTS

Tissue TOS and OSI levels and histomorphological injury scores were statistically lower in treatment groups than I/R group, whereas blood TOS and OSI levels were similar between the groups.

CONCLUSIONS

This study provides biochemical and histomorphological evidence that HRSS prevents intestinal damage in I/R injury caused by volvulus.

Canal of Nuck Abnormalities in Pediatric Female Patients

A groin lump is not an uncommon condition in girls and female infants, and US plays a fundamental role in its exploration. The main pathologic conditions are related to the failure of obliteration of the canal of Nuck. Radiologists should gain a full understanding of the embryology and US anatomy of the inguinal canal before assessing this entity for the first time. An optimal age-adjusted US technique-including examinations at rest and during straining-is essential to help assess the canal of Nuck, diagnose a hernia, and analyze its content. The radiologist must be aware of the various types of hernial content depending on the patient's age, including intestinal, omental, ovarian, or tubouterine hernia, and the US features of each. Incarcerated hernias are common in girls and mostly contain an ovary. In such cases, it is crucial to screen for US signs suggestive of ovarian ischemic damage, thereby calling for urgent surgery. US can also depict a cyst or hydrocele of the canal of Nuck and its complications. Moreover, other rare pathologic conditions involving the inguinal area may be depicted at US, which helps guide appropriate treatment. US is the ideal modality for evaluating an inguinal lump in girls and female infants. Online supplemental material is available for this article. ©RSNA, 2022.

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.

Prediction of bowel obstruction caused by obturator hernia using risk factor categories on clinical characteristics and multidetector computed tomographic findings

PURPOSE

To detect risk factors on clinical characteristics and multidetector computed tomographic (MDCT) findings for predicting bowel obstruction in patients with obturator hernia.

METHODS

We retrospectively reviewed 47 patients who had an obturator hernia diagnosed by MDCT and/or surgery. The patients were divided into obstruction and non-obstruction group based on the presence or absence of bowel obstruction on MDCT images. Uni- and multivariate analyses were performed to identify risk factors for predicting bowel obstruction.

RESULTS

There were 26 patients (55.32%) in the obstruction group and 21 patients (44.68%) in the non-obstruction group. Patients in the obstruction group were older (P = 0.002) and had more women (P = 0.033) and lower body mass index (BMI) (P = 0.0001) than patients in the non-obstruction group. The non-obstruction group suffered fewer bowel obstruction symptoms (P = 0.0001), Howship-Romberg (HR) sign (P = 0.012), deaths (P = 0.008) and major postoperative complications (P = 0.047). The hernia sac in the obstruction group had greater mean major diameter (P = 0.0001) and volume (P = 0.001) than those in the non-obstruction group. Multivariate analysis showed that age [odds ratio (OR) 1.18, 95% confidence interval (CI) 1.00-1.39, P = 0.046] and major diameter of hernia sac (OR 68.17, 95% CI 4.52-1027.70, P = 0.002) were independent risk factors associated with bowel obstruction in patients with obturator hernia.

CONCLUSIONS

Patient's age and major diameter of hernia sac are independent risk factors resulting in bowel obstruction in patients with obturator hernia. Obturator hernia repair before bowel obstruction development may result in better outcomes and fewer postoperative complications.

Postoperative complications of colorectal cancer

Colorectal cancer is the third most common cancer, and surgery is the most common treatment. Several surgical options are available, but each is associated with a range of potential complications. The timely and efficient identification of these complications is vital for effective clinical management of these patients in order to minimise their morbidity and mortality. This review aims to describe the range of commonly performed surgical treatments for colorectal surgery. In addition, frequent post-surgical complications are explored with investigative options explained and illustrated.

Considerations in the Management of Malignant Bowel Obstruction

Malignant bowel obstruction is a challenging clinical problem encountered in patients with advanced abdominal and pelvic malignancies. Although medical therapies form the foundation of management, some patients may be suitable candidates for surgical and procedural interventions. The literature is composed primarily of retrospective single-institution experiences and the results of prospective trials are pending. Given the high symptom burden and limited life expectancy of these patients, management may be best informed by multidisciplinary teams with relevant expertise.

Computed Tomography in Emergency Diagnosis and Management Considerations of Small Bowel Obstruction for Surgical vs. Non-surgical Approach

BACKGROUND

Small bowel obstruction (SBO) accounts for 15% of abdominal pain complaints referred to emergency departments and imposes significant financial burdens on the healthcare system. The absence of passage of flatus or stool and abdominal distention are reported as the most common symptom and a sign of SBO, respectively. Patients who do not demonstrate severe clinical or imaging findings are typically treated with conservative approaches. Patients with clinical signs of sepsis or physical findings of peritonitis are often instantly transferred to the operating room without supplementary imaging assessment. However, in cases where symptoms are non-specific, or the physical examination is challenging, such as in cases with loss of consciousness, the diagnosis can be complicated. This paper discusses the key findings detectable on Computed tomography (CT), which are vital for the emergent triage, proper treatment, and decision making in patients with speculated SBO.

METHOD

Narrative review of the literature.

RESULTS AND CONCLUSION

CT plays a key role in emergent triage, proper treatment, and decision making. It provides high sensitivity, specificity, and accuracy in the detection of early-stage obstruction and acute intestinal vascular compromise. It can also differentiate between various etiologies of this entity which is considered an important criterion in the triage of patients into surgical vs. non-surgical treatment. There are multiple CT findings, such as mesenteric edema, lack of the small-bowel feces, bowel wall thickening, fat stranding in the mesentery, and intraperitoneal fluid, which are predictive of urgent surgical exploration.

Imaging Modalities for Evaluation of Intestinal Obstruction

It is essential for the colon and rectal surgeon to understand the evaluation and management of patients with both small and large bowel obstructions. Computed tomography is usually the most appropriate and accurate diagnostic imaging modality for most suspected bowel obstructions. Additional commonly used imaging modalities include plain radiographs and contrast imaging/fluoroscopy, while less commonly utilized imaging modalities include ultrasonography and magnetic resonance imaging. Regardless of the imaging modality used, interpretation of imaging should involve a systematic, methodological approach to ensure diagnostic accuracy.

Acute abdomen in a 54-year-old COVID-19 patient: a case teport

Although primarily a respiratory virus, coronavirus-19 acts on the gastrointestinal tract to cause symptoms such as anorexia, nausea, vomiting and diarrhea. One possible mechanism involves the ACE2 receptor, which serves as the primary receptor for virus entry into the gastrointestinal epithelium. We describe the case of a 54-year-old-male with recent coronavirus disease 2019 (COVID-19) infection, who later presented with nausea, vomiting, diarrhea and progressively worsening diffuse abdominal pain for 1 week. He was diagnosed to have a small bowel obstruction; however, continued to have progressively worsening pain and failed conservative management. No cause for the obstruction was found in the operating room. Gastrointestinal involvement occurs in at least two-thirds of patients with coronavirus infection. Viral entry into the small bowel, triggering an inflammatory response, and virus-induced microthrombosis of the microcirculation have been postulated as a possible mechanism for paralytic ileus/small bowel obstruction.

Small bowel radiology

PURPOSE OF REVIEW

Recent advances in computed tomography (CT), ultrasound (US), magnetic resonance imaging (MRI), and nuclear radiology have improved the diagnosis and characterization of small bowel pathology. Our purpose is to highlight the current status and recent advances in multimodality noninvasive imaging of the small bowel.

RECENT FINDINGS

CT and MR enterography are established techniques for small bowel evaluation. Dual-energy CT is a novel technique that has shown promise for the mesenteric ischemia and small bowel bleeding. Advanced US techniques and MRI sequences are being investigated to improve assessment of bowel inflammation, treatment response assessment, motility, and mural fibrosis. Novel radiotracers and scanner technologies have made molecular imaging the new reference standard for small bowel neuroendocrine tumors. Computational image analysis and artificial intelligence (AI) have the potential to augment physician expertise, reduce errors and variability in assessment of the small bowel on imaging.

SUMMARY

Advances in translational imaging research coupled with progress in imaging technology have led to a wider adoption of cross-sectional imaging for the evaluation and management of small bowel entities. Ongoing developments in image acquisition and postprocessing techniques, molecular imaging and AI have the strongest potential to transform the care and outcomes of patients with small bowel diseases.

An artificial intelligence deep learning model for identification of small bowel obstruction on plain abdominal radiographs

Objectives:

Small bowel obstruction is a common surgical emergency which can lead to bowel necrosis, perforation and death. Plain abdominal X-rays are frequently used as a first-line test but the availability of immediate expert radiological review is variable. The aim was to investigate the feasibility of using a deep learning model for automated identification of small bowel obstruction.

Methods:

A total of 990 plain abdominal radiographs were collected, 445 with normal findings and 445 demonstrating small bowel obstruction. The images were labelled using the radiology reports, subsequent CT scans, surgical operation notes and enhanced radiological review. The data were used to develop a predictive model comprising an ensemble of five convolutional neural networks trained using transfer learning.

Results:

The performance of the model was excellent with an area under the receiver operator curve (AUC) of 0.961, corresponding to sensitivity and specificity of 91 and 93% respectively.

Conclusion:

Deep learning can be used to identify small bowel obstruction on plain radiographs with a high degree of accuracy. A system such as this could be used to alert clinicians to the presence of urgent findings with the potential for expedited clinical review and improved patient outcomes.

Advances in knowledge:

This paper describes a novel labelling method using composite clinical follow-up and demonstrates that ensemble models can be used effectively in medical imaging tasks. It also provides evidence that deep learning methods can be used to identify small bowel obstruction with high accuracy.

From Blocking Shots to Blocking GI Transit, This Professional Basketball Player Does It All: A Case Report on Small Bowel Obstruction

Small bowel obstructions (SBO) are a commonly encountered diagnosis within emergency departments. Typically, these patients have evident risk factors including, but not limited to, prior abdominal surgery, personal or family history of gastrointestinal disorders, femoral and inguinal hernias, or neoplasm. In this case, we describe an SBO in a female, professional athlete whose swift, severe symptom onset, rapid resolution with conservative treatment, lack of identifiable risk factors, and prompt return to high level competition without recurrence are certainly unique. A female professional basketball player in her mid-20's with no past medical history presented with a seven-hour history of worsening abdominal pain beginning in the epigastric region and migrating to the right lower quadrant. Physical exam did not reveal abdominal distension, tympany to percussion, or high-pitched bowel sounds. Initial differential diagnosis included appendicitis, ruptured ectopic pregnancy, and other genitourinary pathology. Computed tomography with contrast revealed distended loops of small bowel with wall thickening, enhancement, and decompressed loops of bowel distally, consistent with an SBO. Symptoms resolved after 24 hours with conservative treatment, including decompression with a nasogastric tube. The athlete returned to full participation five days after initial presentation without recurrence of symptoms. Outpatient gastroenterology workup was negative for predisposing conditions. This presentation is rare in the absence of bowel pathology, family history, or prior abdominal surgery. Perhaps, her profession as an athlete, with frequent air travel and extensive exercise, may have contributed to this unique presentation. This case report should serve as a reminder to all providers that SBOs can occur in young, active patients devoid of risk factors. Even in the absence of typical signs on physical examination, providers should use imaging as adjuncts based on their clinical gestalt and utilize conservative management, when appropriate, to maximize chances of recovery with minimal morbidity.

Ultrasound of Small Bowel Obstruction: A Pictorial Review

Small bowel obstruction (SBO) is a common condition requiring urgent attention that may involve surgical treatment. Imaging is essential for the diagnosis and characterization of SBO because the clinical presentation and results of laboratory tests may be nonspecific. Ultrasound is an excellent initial imaging modality for assisting physicians in the rapid and accurate diagnosis of a variety of pathologies to expedite management. In the case of SBO diagnosis, ultrasound has an overall sensitivity of 92% (95% CI: 89–95%) and specificity of 93% (95% CI: 85–97%); the aim of this review is to examine the criteria for the diagnosis of SBO by ultrasound, which can be divided into diagnostic and staging criteria. The diagnostic criteria include the presence of dilated loops and abnormal peristalsis, while the staging criteria are represented by parietal and valvulae conniventes alterations and by the presence of free extraluminal fluid. Ultrasound has reasonably high accuracy compared to computed tomography (CT) scanning and may substantially decrease the time to diagnosis; moreover, ultrasound is also widely used in the monitoring and follow-up of patients undergoing conservative treatment, allowing the assessment of loop distension and the resumption of peristalsis.

Bowel ultrasonography in acute abdomen: beyond acute appendicitis

Acute abdomen is a common reason for consultation in the emergency department. A broad spectrum of entities, including diverse diseases of the gastrointestinal tract, can cause acute abdomen. Although computed tomography is the technique most widely used to evaluate acute abdomen in the emergency department, abdominal ultrasound is often performed first and allows bowel disease to be suspected. This article describes the ultrasound features of diverse bowel diseases that can cause acute abdomen, such as acute diverticulitis, bowel obstruction, gastrointestinal perforation, bowel ischemia, intraabdominal fat necrosis, and miscellaneous processes such as endometriosis, foreign bodies, or vasculitis. Radiologists must be familiar with the different features of abnormal bowel that can be detected incidentally in patients without clinical suspicion of bowel disease. This article focuses on ultrasonographic signs of bowel disease; other articles in this series cover the ultrasonographic signs of acute appendicitis, inflammatory bowel disease, and infectious diseases.

Computed Tomography Findings Predicting the Need for Surgery in Cases of Small Bowel Obstruction: Emphasis on Duodenal Distension

OBJECTIVE

The aim of the study is to retrospectively evaluate the utility of computed tomography (CT) findings, especially newly defined duodenal distension, for predicting the need to operate on small bowel obstruction (SBO) cases.

METHODS

During a 51-month period, 228 patients (100 women and 128 men; mean age, 55 years) were included in this study, among 438 patients who were hospitalized with a prediagnosis of SBO. The final study population was then divided into 2 groups: a surgery group (n = 76) and a conservative group (n = 152). The CT findings of the SBO patients whose treatment decisions and outcomes were unknown were examined by 2 gastrointestinal radiologists with consensus. Statistical analyses were conducted using univariate and binary logistic regression analyses.

RESULTS

According to the univariate analysis, the degree of obstruction (P = 0.001), small bowel diameter (P = 0.014), and presence of mesenteric fluid (P < 0.001), intraperitoneal free fluid (P = 0.04), intra-abdominal free gas (P < 0.001), and duodenal distension (P < 0.001) showed statistically significant differences between the surgery and conservative groups. However, there were no statistically significant group differences regarding the presence of a transition point, small bowel feces or mesenteric congestion. According to the binary logistic regression analysis, the degree of obstruction (P = 0.012), presence of mesenteric fluid (P = 0.008), intra-abdominal free gas (P = 0.019), and duodenal distension (P < 0.001) were significant predictors of the need for surgery in SBO cases.

CONCLUSIONS

Duodenal distension as a CT finding predicted the need for surgery in SBO cases.

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

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

Image Annotation by Eye Tracking: Accuracy and Precision of Centerlines of Obstructed Small-Bowel Segments Placed Using Eye Trackers

Small-bowel obstruction (SBO) is a common and important disease, for which machine learning tools have yet to be developed. Image annotation is a critical first step for development of such tools. This study assesses whether image annotation by eye tracking is sufficiently accurate and precise to serve as a first step in the development of machine learning tools for detection of SBO on CT. Seven subjects diagnosed with SBO by CT were included in the study. For each subject, an obstructed segment of bowel was chosen. Three observers annotated the centerline of the segment by manual fiducial placement and by visual fiducial placement using a Tobii 4c eye tracker. Each annotation was repeated three times. The distance between centerlines was calculated after alignment using dynamic time warping (DTW) and statistically compared to clinical thresholds for diagnosis of SBO. Intra-observer DTW distance between manual and visual centerlines was calculated as a measure of accuracy. These distances were 1.1 ± 0.2, 1.3 ± 0.4, and 1.8 ± 0.2 cm for the three observers and were less than 1.5 cm for two of three observers (P < 0.01). Intra- and inter-observer DTW distances between centerlines placed with each method were calculated as measures of precision. These distances were 0.6 ± 0.1 and 0.8 ± 0.2 cm for manual centerlines, 1.1 ± 0.4 and 1.9 ± 0.6 cm for visual centerlines, and were less than 3.0 cm in all cases (P < 0.01). Results suggest that eye tracking-based annotation is sufficiently accurate and precise for small-bowel centerline annotation for use in machine learning-based applications.

Noncontrast MRI of acute abdominal pain caused by gastrointestinal lesions: indications, protocol, and image interpretation

Gastrointestinal tract lesions are major causes of acute abdominal pain. A rapid, accurate, and reliable diagnosis is required to manage patients. Magnetic resonance imaging (MRI) is a nonionizing modality that is beneficial for pregnant women, children, and young adults who are sensitive to ionizing radiation. For patients with renal impairment who are not accurately diagnosed with noncontrast computed tomography, noncontrast MRI can serve as an alternative diagnostic modality. MRI protocols used for acute abdominal pain are supposed to be optimized and prioritized to shorten scanning times. Single-shot T2-weighted and fat-suppressed T2-weighted imaging are important pulse sequences that are used to reveal pathology and inflammation in the gastrointestinal tract. Diffusion-weighted imaging clearly depicts inflammation and abscesses as hyperintense lesions. Most acute gastrointestinal tract lesions, including inflammation, ischemia, obstruction, and perforation, demonstrate bowel wall thickening. Bowel obstruction and adynamic ileus present bowel dilatation, and perforation and penetration show bowel wall defects. MRI can be used to reveal these pathological findings with some characteristics depending on their underlying pathophysiology. This review article discusses imaging modalities for acute abdominal pain, describes a noncontrast MRI protocol for acute abdominal pain caused by gastrointestinal tract lesions, and reviews MRI findings of acute gastrointestinal tract lesions.

Imaging of acute abdomen in cancer patients

The pattern of disease causing acute abdominal pain has changed over last few decades, some of this has been attributed to intraabdominal cancers. The most common acute abdominal complaints in cancer patients are related to the gastrointestinal system. Abdominal emergencies in cancer patients can result from the underlying malignancy itself, cancer therapy and/or result from the standard pathologies causing acute abdomen in otherwise healthy population. Therapy-related or disease-related immunosuppression or high dose analgesics often blunt many of the findings which are usually expected in non-cancer general population. This complicates the clinical picture rendering the clinical exam less reliable in many cancer patients, and resulting in different pathologies which clinicians and the radiologists should remain aware of. This article focuses on imaging illustrations with differential diagnosis for various emergency scenarios related to acute abdomen specifically in oncologic settings.

Adhesive Small Bowel Obstruction: Predictive Radiology to Improve Patient Management

Adhesive small bowel obstruction (SBO) remains one of the leading causes of emergency room visits and is still associated with high morbidity and mortality rates. Because the management of adhesive SBO has shifted from immediate surgery to nonoperative treatment in the absence of ischemia, it is crucial to rapidly detect or predict strangulation, which requires emergent surgery. CT is now established as the best imaging technique for the initial assessment of patients suspected of having adhesive SBO. CT helps confirm the diagnosis of mechanical SBO, locate the site of obstruction, establish the cause, and detect complications. This article is a review of the role of imaging in answering specific questions to help predict the management needs of each individual patient. It includes (a) an update on the best CT signs for predicting ischemia and a need for bowel resection; (b) a discussion of the CT features that help differentiate open-loop from closed-loop obstruction and a single adhesive band from matted adhesions and how these differences can influence the management; and (c) a review of the main CT predictors of the success or failure of nonoperative management in adhesive SBO.

A Comparative Analysis between Laparoscopic and Open Adhesiolysis at a Tertiary Care Center

Laparotomy has been the favored approach regarding surgical management of small bowel obstruction (SBO); however, laparoscopy may offer improved outcomes. Patients undergoing laparoscopic lysis of adhesions (LOA) at our institution for SBO will have lower postoperative morbidity and 30-day mortality. Patients undergoing LOA at our institution, from 2000 to 2011, were reviewed. Categorical data were analyzed with χ2or Fisher's exact tests. Continuous data were analyzed with Student's t test or Wilcoxon rank sum. One hundred two (38 laparoscopic, 64 open) LOA cases were selected. Perioperative contamination and conservative management were higher in the open group. Open cases had a greater incidence of intensive care unit (ICU) admissions and longer length of stay. Stratified analysis determined a strong association between perioperative contamination and a higher incidence of ICU admission, perioperative contamination and longer LOS, and conservative management and longer LOS. Finally, patient outcome did not differ between those treated by surgeons trained in minimally invasive surgery (MIS) compared with those not trained in MIS. Careful consideration of surgical approach and timing is called for in all patients with SBO; however, whenever possible, laparoscopic preference should be given to most patients in an expeditious fashion irrespective of MIS training.

Ultrasound Signs in the Diagnosis and Staging of Small Bowel Obstruction

Ultrasound (US) is highly accurate in the diagnosis of small bowel obstruction (SBO). Because the indications for and timing of surgical intervention for SBO have changed over the past several decades, there is a widespread assumption that the majority of patients with simple SBO may be conservatively managed; in this scenario, staging SBO is crucial. This study evaluated the association between morphological and functional US signs in the diagnosis and staging (simple, decompensated and complicated), and the associations and prevalence of US signs correlated with clinical or surgical outcome. The US signs were divided into diagnostic (dilated bowel loops and altered kinesis) and staging criteria (extraluminal free fluid, parietal and villi alterations). We performed a retrospective, single-center cohort, observational study examining the prevalence of morphologic and functional US signs in the staging of simple, decompensated and complicated SBO. The most significant US signs were dilated bowel loops (100%), hypokinesis (90.46%), thickened walls (82.54%) and free fluid (74.60%). By linear regression, free fluid was positively correlated to US staging in both univariate and multivariate analysis; that is, the more advanced the stage of SBO, the more probable the presence of free fluid between the bowel loops. In univariate analysis only, we found a positive correlation between US staging/thickened walls and the prominence of valvulae conniventes. Additionally, the multivariate analysis indicated that parietal stratification and bowel jump kinesis were negative predictors for US staging in comparison to other US signs. In addition, we found significant associations between conservative treatment or surgery and hypokinesis (p = 0.0326), akinesis (p = 0.0326), free fluid (p = 0.0013) and prominence of valvulae conniventes (p = 0.011). Free fluid in particular was significantly less present in patients that were conservatively treated (p = 0.040). We conclude that the US staging of SBO may be crucial, with a valuable role in the initial diagnosis and staging of the pathology, saving time and reducing total radiation exposure to the patient.