ACR Appropriateness Criteria® Acute Nonlocalized Abdominal Pain

A retrieval-augmented chatbot based on GPT-4 provides appropriate differential diagnosis in gastrointestinal radiology: a proof of concept study

BACKGROUND

We investigated the potential of an imaging-aware GPT-4-based chatbot in providing diagnoses based on imaging descriptions of abdominal pathologies.

METHODS

Utilizing zero-shot learning via the LlamaIndex framework, GPT-4 was enhanced using the 96 documents from the Radiographics Top 10 Reading List on gastrointestinal imaging, creating a gastrointestinal imaging-aware chatbot (GIA-CB). To assess its diagnostic capability, 50 cases on a variety of abdominal pathologies were created, comprising radiological findings in fluoroscopy, MRI, and CT. We compared the GIA-CB to the generic GPT-4 chatbot (g-CB) in providing the primary and 2 additional differential diagnoses, using interpretations from senior-level radiologists as ground truth. The trustworthiness of the GIA-CB was evaluated by investigating the source documents as provided by the knowledge-retrieval mechanism. Mann-Whitney U test was employed.

RESULTS

The GIA-CB demonstrated a high capability to identify the most appropriate differential diagnosis in 39/50 cases (78%), significantly surpassing the g-CB in 27/50 cases (54%) (p = 0.006). Notably, the GIA-CB offered the primary differential in the top 3 differential diagnoses in 45/50 cases (90%) versus g-CB with 37/50 cases (74%) (p = 0.022) and always with appropriate explanations. The median response time was 29.8 s for GIA-CB and 15.7 s for g-CB, and the mean cost per case was $0.15 and $0.02, respectively.

CONCLUSIONS

The GIA-CB not only provided an accurate diagnosis for gastrointestinal pathologies, but also direct access to source documents, providing insight into the decision-making process, a step towards trustworthy and explainable AI. Integrating context-specific data into AI models can support evidence-based clinical decision-making.

RELEVANCE STATEMENT

A context-aware GPT-4 chatbot demonstrates high accuracy in providing differential diagnoses based on imaging descriptions, surpassing the generic GPT-4. It provided formulated rationale and source excerpts supporting the diagnoses, thus enhancing trustworthy decision-support.

KEY POINTS

• Knowledge retrieval enhances differential diagnoses in a gastrointestinal imaging-aware chatbot (GIA-CB). • GIA-CB outperformed the generic counterpart, providing formulated rationale and source excerpts. • GIA-CB has the potential to pave the way for AI-assisted decision support systems.

Canadian Association of Radiologists Gastrointestinal Imaging Referral Guideline

The Canadian Association of Radiologists (CAR) Gastrointestinal Expert Panel consists of radiologists, a gastroenterologist, a general surgeon, a family physician, a patient advisor, and an epidemiologist/guideline methodologist. After developing a list of 20 clinical/diagnostic scenarios, a systematic rapid scoping review was undertaken to identify systematically produced referral guidelines that provide recommendations for one or more of these clinical/diagnostic scenarios. Recommendations from 58 guidelines and contextualization criteria in the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) for guidelines framework were used to develop 85 recommendation statements specific to the adult population across the 20 scenarios. This guideline presents the methods of development and the referral recommendations for dysphagia/dyspepsia, acute nonlocalized abdominal pain, chronic abdominal pain, inflammatory bowel disease, acute gastrointestinal bleeding, chronic gastrointestinal bleeding/anemia, abnormal liver biopsy, pancreatitis, anorectal diseases, diarrhea, fecal incontinence, and foreign body ingestion.

The utility of the abdominal series in the emergency setting: a retrospective review

PURPOSE

The abdominal series (AXR) remains a frequently ordered test in the emergency department (ED), despite existing literature questioning its utility. The aim of this study was to characterize the use of the AXR in the ED by quantifying how often it is ordered and the frequency of subsequent imaging. Additionally, a time estimate in ED associated with the AXR was quantified. We hypothesized that there would be a low clinical utility of the AXR, and long associated time period spent in the ED.

METHODS

A retrospective audit of AXRs performed in the ED from January to December 2019 was performed. The local picture archiving and communication system (PACS) and electronic medical record were used to collect the variables.

RESULTS

Of 701 AXRs, 438 (62.4%) were reported normal, and 263 (37.6%) were abnormal. A Chi Squared test showed that the two variables (abdominal series result and follow up imaging completion) were significantly related, with p < 0.001. However, the effect size was small (Nagelkerke R square = 0.022). The average time spent in the ED for these patients was 7.27 h, and the average time between the AXR being ordered and interpreted was 1.31 h.

CONCLUSION

The majority of AXRs were reported as normal. Our results showed that AXR had a statistically significant, but low clinically significant predictive ability on subsequent imaging ordering. This supports our hypothesis that the AXR is of low clinical utility with respect to the rate of ordering follow up imaging. The AXR also translated to a quantifiable time interval during the patient's stay in ED. Minimizing overuse of the AXR may result in a decrease in patient duration in the ED.

Diagnostic Yield of Abdominal Radiographs in the Pediatric Emergency Department

BACKGROUND AND OBJECTIVES

Abdominal radiographs (ARs) are commonly used in the pediatric emergency department (PED). Their low diagnostic accuracy leads to overuse, excess radiation exposure, and increased resource usage. This study aims to assess the diagnostic yield of ARs in the evaluation of intraabdominal pathology in the PED.

METHODS

Retrospective, cross-sectional study of patients aged 0 to 18 years with an AR who visited the PED between 2017 and 2019. Diagnostic yield was analyzed with sensitivity, specificity, positive predictive value, negative predictive value (NPV), and likelihood ratio.

RESULTS

A total of 4288 ARs were identified, with a rate of 6%. The overall abnormal AR rate was 31%. The incidences of an abnormal AR in abdominal pain, vomiting, and constipation were 26%, 37%, and 50%, respectively. There was a 13% rate of clinically significant diagnoses. The AR diagnostic yield showed 44% sensitivity, 70% specificity, 17% positive predictive value, and 90% NPV ( P < 0.05). Unadjusted odds ratio analysis of positive AR and abdominal pain, vomiting, and constipation revealed an odds ratio of 0.68 (95% confidence interval [CI], 0.63-0.75), 1.22 (95% CI, 1.06-1.39), and 1.72 (95% CI, 1.54-1.91), respectively.

CONCLUSIONS

There is a low rate of intraabdominal pathologic processes that an AR can identify. A normal AR does not change patient management, nor does it reduce the need for further radiologic imaging. Despite a good NPV, the AR is not a useful diagnostic tool in the PED because of its limited ability to rule in or rule out clinically significant diagnoses.

Acute Pelvic Pain: Role of Imaging in the Diagnosis and Management

Acute pelvic pain is defined as a new symptom that has been present for less than 3 months. It is a common symptom seen in 15%-24% of women and is the indication for 20% of laparoscopies and 2%-10% of outpatient gynecologic visits. The pregnancy status and correlation of the physical symptoms with clinical findings are important. Ultrasound is the imaging modality of choice, not only to diagnose gynecological causes, but also bowel or urinary tract related causes of pelvic pain. When an ultrasound scan is inconclusive, a computed tomography scan is the preferred means of additional imaging and is particularly useful in gastrointestinal and urogenital causes of pelvic pain. Gynecological causes of acute pelvic pain include uterine, tubal, or ovarian pathology; non-gynecological causes include bowel diseases, such as appendicitis and diverticulitis; urogenital causes such as ureteral, bladder stones, and urinary tract infection as well as vascular causes. Ultrasound imaging alone may provide a definitive diagnosis in underlying conditions that require prompt medical or surgical intervention in gynecological conditions, such as ovarian torsion, ectopic pregnancy, and non-gynecological condition, such as in acute appendicitis.

Assessing the necessity of intravenous contrast for computed tomography in the acute undifferentiated abdomen

INTRODUCTION

Undifferentiated abdominal pain in the emergency setting is frequently investigated with an intravenous contrast enhanced CT as a first line diagnostic test. However, global contrast shortages restricted the use of contrast for a period in 2022, altering standard practice with many scans performed without intravenous contrast. Whilst IV contrast can be useful to assist with interpretation, its necessity in the setting of acute undifferentiated abdominal pain is not well described, and its use comes with its own risks. This study aimed to assess the shortcomings of omitting IV contrast in an emergency setting, by comparing the rate of CT scans with "indeterminate" findings with and without the use of IV contrast.

METHODS

Data from presentations to a single centre emergency department for undifferentiated abdominal pain prior to and during contrast shortages in June 2022 were retrospectively compared. The primary outcome was the rate of diagnostic uncertainty, where the presence or absence of intra-abdominal pathology could not be ascertained.

RESULTS

12/85 (14.1%) of the unenhanced abdominal CT scans provided an uncertain result, compared with 14/101 (13.9%) of control cases performed with intravenous contrast (P = 0.96). There were also similar rates of positive and negative findings between the groups.

CONCLUSION

Omitting intravenous contrast for abdominal CT in the setting of undifferentiated abdominal pain demonstrated no significant difference in the rate of diagnostic uncertainty. There are significant potential patient, fiscal and societal benefits as well as potential improvements to emergency department efficiency with the reduction of unnecessary intravenous contrast administration.

Imaging of Acute Abdominopelvic Pain in Pregnancy and Puerperium-Part II: Non-Obstetric Complications

Emergency imaging in pregnancy and puerperium poses unique challenges both for clinicians and radiologists, requiring timely and accurate diagnosis. Delay in treatment may result in poor outcomes for both the patient and the foetus. Pregnant and puerperal patients may present in the emergency setting with acute abdominopelvic pain for various complications that can be broadly classified into obstetric and non-obstetric related diseases. Ultrasonography (US) is the primary diagnostic imaging test; however, it may be limited due to the patient's body habitus and the overlapping of bowel loops. Computed tomography (CT) carries exposure to ionising radiation to the foetus, but may be necessary in selected cases. Magnetic resonance imaging (MRI) is a valuable complement to US in the determination of the etiology of acute abdominal pain and can be used in most settings, allowing for the identification of a broad spectrum of pathologies with a limited protocol of sequences. In this second section, we review the common non-obstetric causes for acute abdominopelvic pain in pregnancy and post partum, offering a practical approach for diagnosis and pointing out the role of imaging methods (US, MRI, CT) with the respective imaging findings.

Imaging of Acute Abdominopelvic Pain in Pregnancy and Puerperium-Part I: Obstetric (Non-Fetal) Complications

Acute abdominopelvic pain in pregnant and postpartum patients presents clinical and therapeutic challenges, often requiring quick and accurate imaging diagnosis. Ultrasound remains the primary imaging investigation. Magnetic resonance imaging (MRI) has been shown to be a powerful diagnostic tool in the setting of acute abdominal pain during pregnancy and puerperium. MRI overcomes some drawbacks of US, avoiding the ionizing radiation exposure of a computed tomography (CT) scan. Although CT is not usually appropriate in pregnant patients, it is crucial in the emergency evaluation of postpartum complications. The aim of this article is to provide radiologists with a thorough familiarity with the common and uncommon pregnancy and puerperium abdominal emergencies by illustrating their imaging appearances. The present first section will review and discuss the imaging findings for acute abdominopelvic pain of obstetric (non-fetal) etiology.

ACR Appropriateness Criteria® Right Upper Quadrant Pain: 2022 Update

Acute right upper quadrant pain is one of the most common presenting symptoms in hospital emergency departments, as well as outpatient settings. Although gallstone-related acute cholecystitis is a leading consideration in diagnosis, a myriad of extrabiliary sources including hepatic, pancreatic, gastroduodenal, and musculoskeletal should also be considered. This document focuses on the diagnostic accuracy of imaging studies performed specifically to evaluate acute right upper quadrant pain, with biliary etiologies including acute cholecystitis and its complications being the most common. An additional consideration of extrabiliary sources such as acute pancreatitis, peptic ulcer disease, ascending cholangitis, liver abscess, hepatitis, and painful liver neoplasms remain a diagnostic consideration in the right clinical setting. The use of radiographs, ultrasound, nuclear medicine, CT, and MRI for these indications are discussed. The ACR 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.

What's new in the hot gallbladder: the evolving radiologic diagnosis and management of acute cholecystitis

Acute cholecystitis (AC) is a common condition and its incidence is rising. New technologies have advanced the imaging diagnosis of AC, providing more structural and functional information as well as allowing the radiologist to distinguish AC from mimics and identify complications from both the disease and its management. Dual energy CT aids in detecting gallstones and gallbladder wall enhancement, which helps to diagnose AC and identify its complications. Similarly, contrast-enhanced and non-contrast perfusion ultrasound techniques improve detection of abnormal gallbladder wall enhancement. Advances in MR imaging including hepatobiliary contrast agents aid in characterizing post-cholecystectomy complications such as bile leaks. Newer interventional techniques have also expanded the suite of options for minimally invasive management. Lumen apposing metal stents provide more options for conservative treatment in non-surgical candidates and are compared to a standard percutaneous cholecystostomy. Radiologists should be familiar with these advanced imaging methods and intervention techniques and the value they can bring to the diagnosis and management of AC.

Implementing Bundle Care in Major Abdominal Emergency Surgery: Long-Term Mortality and Comprehensive Complication Index

BACKGROUND

Major abdominal emergency surgery (MAES) has a high risk of postoperative mortality and a high complication rate. The aim of this study was to evaluate whether the implementation of a perioperative care bundle reduced long-term mortality and the Comprehensive Complication Index (CCI) after MAES.

METHODS

This study was a single-centre retrospective cohort study. Data in the intervention group were collected prospectively and compared with a historical cohort from the same centre. It includes adult patients undergoing MAES. We implemented a care bundle under the name Abdominal Surgery Acute Protocol (ASAP). We initiated fast-track initiatives and standardised optimised care in before, during and after surgery. Data were analysed using survival analysis and multiple regression.

RESULTS

We included 120 patients in the intervention cohort and 258 in the historical cohort. The one-year mortality rate was 21.7% in the intervention cohort compared to 28.3% in the standard care cohort. Adjusted odds ratio of one-year mortality 0.81 (CI95% 0.41-1.56). The 30-day mortality was lowered from 19.0 to 6.7% (p = 0.003). The CCI in the intervention cohort was 8.7 (IQR 0-34) compared to 21 (IQR 0-36) in the control cohort (p = 0.932) The length of stay increased by two days (p = 0.021). Most cases had 71-80% protocol compliance.

CONCLUSION

Implementing bundle care in major abdominal emergency surgery lowered the 30-day postoperative mortality. The difference in mortality was preserved over time although not significant after one year. The changes in the Comprehensive Complication Index were not statistically significant.

ACR Appropriateness Criteria® Hernia

Abdominopelvic hernias are common clinical entities composed of a wide variety of congenital, traumatic, and iatrogenic etiologies. Any weakness in the body wall may result in hernia of cavity contents with concomitant risks of morbidity and mortality. Presentations may be specific, palpable body wall mass/bulge, or vague, nonspecific pain through bowel obstruction. This document focuses on initial imaging of the adult population with signs of symptoms prompting suspicion of abdominopelvic hernia. Imaging of the abdomen and pelvis to evaluate defects is essential for prompt diagnosis and treatment. Often CT and ultrasound are the first-line modalities to quickly evaluate the abdomen and pelvis, providing for accurate diagnoses and management of patients. MRI protocols may be useful as first-line imaging studies, especially in patients with orthopedic instrumentation. Although often performed, abdominal radiographs and fluorographic procedures may provide indirect evidence of hernias but are usually not indicated for initial diagnosis of hernia. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer-reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which peer-reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Interpretation discrepancies of abdominal imaging by on-call radiology residents: Evaluation of risk factors

The aim of this study was to determine the rate, important findings, and risk factors related to discrepancies between on-call residents’ and attending radiologists’ interpretations of abdominal examinations. We identified 1132 eligible patients with abdominal radiology findings that were preliminary interpreted by on-call residents between February 2016 and September 2019. The preliminary interpretations were compared with the final interpretations by abdominal attending radiologists, including clinical data. The preliminary interpretations were analyzed by three radiologists in consensus, who categorized the reports according to organs, important findings (i.e., active bleeding, bowel obstruction, organ ischemia or infarction, and organ rupture), clinical outcomes, and discrepancies with respect to final interpretations. Multiple logistic regression analysis was used to evaluate the risk factors for important discrepant findings. Of 1132 patients, the bowel (n = 567, 50.1%) was the most common organ interpreted by on-call residents, followed by gallbladder/bile duct/pancreas (n = 139, 12.3%) and liver (n = 116, 10.2%). Of 1132, 359 patients (31.7%) had disease with 379 important findings: active bleeding (n = 222), organ rupture (n = 77), bowel obstruction (n = 52), bowel ischemia (n = 24), and organ infarction (n = 4). Sixty-four patients (5.6%) showed discrepancies, and 30 (2.6%) showed 32 important discrepant findings comprising 14 active bleeding, 10 bowel obstructions, 6 organ ruptures, and 2 cases of bowel ischemia. Of the 64 discrepant patients, 33 underwent delayed surgery (n = 18, 28.1%) or interventional treatment (n = 15, 23.4%). In multivariable analysis, bowel obstruction (adjusted odds ratio, 2.52; p = 0.049) was an independent risk factor for determining discrepancy between preliminary and final interpretations. The rate of overall and important discrepancies between on-call residents’ and final interpretations was low. However, given that the bowel was the most frequently interpreted organ, bowel obstruction was identified as a risk factor for discrepant interpretations. The identified risk factor and findings may be useful for residents to minimize discrepancies.

Abdominal Pain in the Emergency Department: How to Select the Correct Imaging for Diagnosis

Abdominal pain is a common presenting complaint in the emergency department, and utilization of diagnostic imaging is often a key tool in determining its etiology. Plain radiography has limited utility in this population. Computed tomography (CT) is the imaging modality of choice for undifferentiated abdominal pain. Ultrasound and magnetic resonance imaging may be helpful in specific scenarios, primarily in pediatrics and pregnancy, and offer the benefit of eliminating ionizing radiation risk of CT. Guidance for imaging selection is determined by location of pain, special patient considerations, and specific suspected etiologies. Expert guidance is offered by the American College of Radiology Appropriateness Criteria^® which outlines imaging options based on location of pain.

Guidelines for Reasonable and Appropriate Care in the Emergency Department 2 (GRACE-2): Low-risk, recurrent abdominal pain in the emergency department

This second Guideline for Reasonable and Appropriate Care in the Emergency Department (GRACE-2) from the Society for Academic Emergency Medicine is on the topic "low-risk, recurrent abdominal pain in the emergency department." The multidisciplinary guideline panel applied the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to assess the certainty of evidence and strength of recommendations regarding four priority questions for adult emergency department patients with low-risk, recurrent, undifferentiated abdominal pain. The intended population includes adults with multiple similar presentations of abdominal signs and symptoms recurring over a period of months or years. The panel reached the following recommendations: (1) if a prior negative computed tomography of the abdomen and pelvis (CTAP) has been performed within 12 months, there is insufficient evidence to accurately identify populations in whom repeat CTAP imaging can be safely avoided or routinely recommended; (2) if CTAP with IV contrast is negative, we suggest against ultrasound unless there is concern for pelvic or biliary pathology; (3) we suggest that screening for depression and/or anxiety may be performed during the ED evaluation; and (4) we suggest an opioid-minimizing strategy for pain control. EXECUTIVE SUMMARY: The GRACE-2 writing group developed clinically relevant questions to address the care of adult patients with low-risk, recurrent, previously undifferentiated abdominal pain in the emergency department (ED). Four patient-intervention-comparison-outcome-time (PICOT) questions were developed by consensus of the writing group, who performed a systematic review of the literature and then synthesized direct and indirect evidence to formulate recommendations, following GRADE methodology. The writing group found that despite the commonality and relevance of these questions in emergency care, the quantity and quality of evidence were very limited, and even fundamental definitions of the population and outcomes of interest are lacking. Future research opportunities include developing precise and clinically relevant definitions of low-risk, recurrent, undifferentiated abdominal pain and determining the scope of the existing populations in terms of annual national ED visits for this complaint, costs of care, and patient and provider preferences.

e Silva L, Bellolio F, Upadhye S, Broder JS. Repeat computed tomography in recurrent abdominal pain: An evidence synthesis for guidelines for reasonable and appropriate care in the emergency department

OBJECTIVE

Computed tomography (CT) imaging is frequently obtained for recurrent abdominal pain after a prior emergency department (ED) evaluation. We evaluate the utility of repeat CT imaging following an indeterminate index CT in low-risk abdominal pain adult ED patients.

METHODS

An electronic search was designed for the patient-intervention-control-outcome-timing (PICOT) question: (P) adult patients with low-risk, recurrent, and previously undifferentiated atraumatic abdominal pain presenting to the ED after an index-negative CT within 12 months; (I) repeat CT versus (C) no repeat CT; for (O) abdominal surgery or other invasive procedure, mortality, identification of potentially life-threatening diagnosis, and hospital and intensive care unit admission rates; and return ED visit (T), all within 30 days. Four reviewers independently selected evidence for inclusion and then synthesized the results around the most prevalent themes of repeat CT timing, diagnostic yield, ionizing radiation exposure, and predictors of repetitive imaging.

RESULTS

Although 637 articles and abstracts were identified, no direct evidence was found. Thirteen documents were synthesized as indirect evidence. None of the indirect evidence defined a low-risk subset of abdominal pain nor did investigators describe whether reimaging occurred for complaints similar to the initial ED evaluation. Included studies did not describe the index CT findings and some reported explanatory findings noted on the original CT for which repeat CTs might have been indicated. The time frame for a repeat CT ranged from hours to 1 year. The frequency of repeat CTs (2%-47%) varied across studies as did the yield of imaging to alter downstream clinical decision making (range = 5%-67%).

CONCLUSION

Due to the absence of direct evidence our scoping review is unable to provide high-quality evidence-based recommendations upon which to confidently base an imaging practice guideline. There is no evidence to support or refute performing a CT for low-risk recurrent abdominal pain.

Abdominal CT findings in Puumala hantavirus-infected patients

BACKGROUND

Previous clinical studies have reported abdominal findings on ultrasonography or MRI in Puumala hantavirus-infected patients.

PURPOSE

To determine if abdominal computed tomography (CT) can lead to a diagnosis of Puumala virus infection in the presence of a suggestive clinical picture.

MATERIAL AND METHODS

CT findings were studied retrospectively in 30 patients who presented to the emergency department of two (Belgian) hospitals with serologically confirmed Puumala hantavirus infection.

RESULTS

The most frequent finding was perirenal fascial thickening (90%), followed by perirenal fat stranding (87%). Retroperitoneal fat stranding was found in 19 patients (64%) in the perivesical spaces along the fascia of the external iliac vessels with or without involvement of the presacral fat. Half of the patients had pelvic ascites, and pleural fluid was found in 7 of them. The right and left mean pole-to-pole kidney's lengths were respectively 125.7 mm and 127.8 mm in 28 patients.

CONCLUSION

Retroperitoneal fat stranding, perirenal fascial thickening and/or perirenal fat stranding were found in most patients with acute Puumala virus infection who have undergone CT. Although nonspecific, these findings may help to suggest Puumala hantavirus infection in the right clinical settings.

Evaluation and disposition of older adults presenting to the emergency department with abdominal pain

BACKGROUND

Abdominal pain is the most common chief complaint in US emergency departments (EDs) among patients over 65, who are at high risk of mortality or incident disability after the ED encounter. We sought to characterize the evaluation, management, and disposition of older adults who present to the ED with abdominal pain.

METHODS

We performed a survey-weighted analysis of the National Hospital Ambulatory Medical Care Survey (NHAMCS), comparing older adults with a chief complaint of abdominal pain to those without. Visits from 2013 to 2017 to nationally representative EDs were included. We analyzed 81,509 visits to 1211 US EDs, which projects to 531,780,629 ED visits after survey weighting. We report the diagnostic testing, evaluation, management, additional reasons for visit, and disposition of ED visits.

RESULTS

Among older adults (≥65 years), 7% of ED visits were for abdominal pain. Older patients with abdominal pain had a lower probability of being triaged to the "Emergent" (ESI2) acuity on arrival (7.1% vs. 14.8%) yet were more likely to be admitted directly to the operating room than older adults without abdominal pain (3.6% vs. 0.8%), with no statistically significant differences in discharge home, death, or admission to critical care. Ultrasound or CT imaging was performed in 60% of older adults with abdominal pain. A minority (39%) of older patients with abdominal pain received an electrocardiogram (EKG).

CONCLUSIONS

Abdominal pain in older adults presenting to EDs is a serious condition yet is triaged to "emergent" acuity at half the rate of other conditions. Opportunities for improving diagnosis and management may exist. Further research is needed to examine whether improved recognition of abdominal pain as a syndromic presentation would improve patient outcomes.

Imaging of acute pelvic pain

Acute pelvic pain (APP) requires urgent medical evaluation and treatment. Differential diagnosis of APP is broad, including a variety of gynecologic and non-gynecologic/ urinary, gastrointestinal, vascular and other entities. Close anatomical and physiological relations of pelvic structures, together with similar clinical presentation of different disorders and overlapping of symptoms, especially in the emergency background, make the proper diagnosis of APP challenging. Imaging plays a crucial role in the fast and precise diagnosis of APP. Ultrasonography is the first-line imaging modality, often accompanied by CT, while MRI is utilized in specific cases, using short, tailored protocols. Recognizing the cause of APP in females is a challenging task, due to the wide spectrum of possible origin and overlap of their imaging features. Therefore, the radiologist has to be familiar with the possible causes of APP, and, relying on clinical presentation, together with laboratory findings, choose the best imaging strategy in order to establish a fast and accurate diagnosis.

Approach to Abdominal Imaging in 2022

Abdominal pain represents 5% to 7% of all emergency department presentations. Many patients require imaging for diagnosis, and choosing the appropriate imaging modality is a crucial decision point. Modern medicine offers a fantastic array of options including abdominal radiograph, computed tomography, MRI, and ultrasonography, but the plethora of alternatives can be paralyzing. This article introduces the commonly available modalities, discusses the advantages and disadvantages, and presents current recommendations for commonly diagnosed conditions.

Postprocedural Gastrointestinal Emergencies

Postprocedural complications encompass a wide array of conditions that vary in acuity, symptoms, index procedure, and treatment. Continued advancements in diagnostic and therapeutic procedures have led to a significant shift of procedures to the ambulatory setting. This trend is of particular interest to the emergency physician, as patients who develop complications often present to an emergency department for evaluation and treatment. Here the authors examine a high-yield collection of procedures, both ambulatory and inpatient, notable for their frequent utilization and unique complication profiles including common laparoscopic surgical procedures, bariatric surgery, endoscopic procedures, interventional radiology procedures, and hernia repairs with implantable mesh.

Problem-solving with MRI in acute abdominopelvic conditions, part 1: gastrointestinal, hepatobiliary, and pancreatic diseases

The purpose of this article is to review the benefit and added value and advantages of magnetic resonance imaging (MRI) compared with other cross-sectional imaging in patients presenting with abdominopelvic emergencies. During the past decade, there has been increased utilization of MRI in the emergency department with widespread availability of MR scanners, improvement in rapid imaging techniques, and methods to overcome motion-related artifacts. This has benefited patients at higher risk of radiation, particularly children and pregnant women, and patients with contraindications to iodinated contrast including allergy and renal dysfunction. Still the challenges are: on site MR scanner in the emergency department, after-hour services, as well as availability of time slot to rapidly scan emergency patient. MRI has additional advantages over other imaging modalities due to its high contrast resolution, which allows it to better characterize tissue and fluid collections, and may avoid the need for intravenous contrast. Radiologists must be familiar with the role and added value of MRI, spectrum of imaging findings, and problem-oriented modified MR protocols in abdominal and pelvic emergencies. In part 1, we will discuss the utility of MRI in gastrointestinal, hepatobiliary, and pancreatic diseases. In part 2, the authors will focus on the key MR imaging features of female pelvic gynecological diseases, pregnancy related complications, abdominal vascular complications, and renal diseases.

Role of MRI in the Evaluation of Thoracoabdominal Emergencies

Thoracic and abdominal pathology are common in the emergency setting. Although computed tomography is preferred in many clinical situations, magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) have emerged as powerful techniques that often play a complementary role to computed tomography or may have a primary role in selected patient populations in which radiation is of specific concern or intravenous iodinated contrast is contraindicated. This review will highlight the role of MRI and MRA in the emergent imaging of thoracoabdominal pathology, specifically covering acute aortic pathology (acute aortic syndrome, aortic aneurysm, and aortitis), pulmonary embolism, gastrointestinal conditions such as appendicitis and Crohn disease, pancreatic and hepatobiliary disease (pancreatitis, choledocholithiasis, cholecystitis, and liver abscess), and genitourinary pathology (urolithiasis and pyelonephritis). In each section, we will highlight the specific role for MRI, discuss basic imaging protocols, and illustrate the MRI features of commonly encountered thoracoabdominal pathology.

Deep learning-based algorithm to detect primary hepatic malignancy in multiphase CT of patients at high risk for HCC

OBJECTIVES

To develop and evaluate a deep learning-based model capable of detecting primary hepatic malignancies in multiphase CT images of patients at high risk for hepatocellular carcinoma (HCC).

METHODS

A total of 1350 multiphase CT scans of 1280 hepatic malignancies (1202 HCCs and 78 non-HCCs) in 1320 patients at high risk for HCC were retrospectively analyzed. Following the delineation of the focal hepatic lesions according to reference standards, the CT scans were categorized randomly into the training (568 scans), tuning (193 scans), and test (589 scans) sets. Multiphase CT information was subjected to multichannel integration, and livers were automatically segmented before model development. A deep learning-based model capable of detecting malignancies was developed using a mask region-based convolutional neural network. The thresholds of the prediction score and the intersection over union were determined on the tuning set corresponding to the highest sensitivity with < 5 false-positive cases per CT scan. The sensitivity and the number of false-positives of the proposed model on the test set were calculated. Potential causes of false-negatives and false-positives on the test set were analyzed.

RESULTS

This model exhibited a sensitivity of 84.8% with 4.80 false-positives per CT scan on the test set. The most frequent potential causes of false-negatives and false-positives were determined to be atypical enhancement patterns for HCC (71.7%) and registration/segmentation errors (42.7%), respectively.

CONCLUSIONS

The proposed deep learning-based model developed to automatically detect primary hepatic malignancies exhibited an 84.8% of sensitivity with 4.80 false-positives per CT scan in the test set.

KEY POINTS

• Image processing, including multichannel integration of multiphase CT and automatic liver segmentation, enabled the application of a deep learning-based model to detect primary hepatic malignancy. • Our model exhibited a sensitivity of 84.8% with a false-positive rate of 4.80 per CT scan.

Influence of clinical suspicion on CT accuracy of acute mesenteric ischemia: Retrospective study of 362 patients

PURPOSE

Acute mesenteric ischemia (AMI) may be underdiagnosed when not clinically suspected before CT is performed. We assessed the influence of a clinical suspicion of AMI on the CT accuracy.

METHOD

This retrospective single-centre study included patients who underwent CT in 2014-2019 and had clinically suspected AMI and/or confirmed AMI. CT protocols were adapted based on each patient's presentation and on findings from unenhanced images. The CT protocol was considered optimal for AMI when it included arterial and portal venous phases. CT protocols, accuracy of reports, and outcomes were compared between the groups with and without suspected AMI before CT.

RESULTS

Of the 375 events, 337 (90 %) were suspected AMI and 66 (18 %) were AMI, including 28 (42 %) with and 38 without suspected AMI. These two groups did not differ significantly regarding the medical history, clinical presentation, or laboratory tests. The CT protocol was more often optimal for AMI in the group with suspected AMI (26/28 [93 %] vs. 28/38 [74 %], p = 0.046). Diagnostic accuracy was not different between groups with and without suspected AMI (26/28 [93 %] vs. 34/38 [90 %], p = 1.00). However, it was lower in the group without suspicion of AMI when the CT protocol was not optimal for AMI (27/28 [96 %] vs 7/10 [70 %], p = 0.048).

CONCLUSIONS

The negative influence of not clinically suspecting AMI can be mitigated by using a tailored CT protocol.

[Upper abdominal pain: a frequent and multifaceted leading symptom in primary care internal medicine]

Upper gastrointestinal symptoms are among the most common reasons for medical consultation and represent a challenge for general practitioners in the outpatient care setting. History taking, symptom evaluation and physical examination are the crucial steps toward establishing an initial working diagnosis. The subsequent abdominal ultrasound and laboratory analyses are essential tools for the differential diagnosis.

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.

ACR Appropriateness Criteria® Acute Nonspecific Chest Pain-Low Probability of Coronary Artery Disease

Patients with acute nonspecific chest pain and low probability for coronary disease remain an important clinical management dilemma. We focus on evidence for imaging, in an integrated decision-making setting. 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.

Advanced Fusion Imaging and Contrast-Enhanced Imaging (CT/MRI-CEUS) in Oncology

Simple Summary

Fusion imaging depicts an innovative technique by which previously performed computed tomography/magnetic resonance imaging can be integrated and reconstructed with advanced contrast-enhanced ultrasound using modern ultrasound devices in a real-time manner. Fusion imaging allows for complementing strengths and reducing restrictions of the combined imaging modalities. The visualization of parenchymal and tumoral microperfusion by contrast-enhanced ultrasound can be dynamically fused and assessed with images from previous cross-sectional studies and may help to decipher underlying entities of indeterminate lesions or validate suspicious morphology. The findings from our study demonstrate the benefits of fusion imaging for evaluating focal hepatic and renal lesions. The excellent safety profile, accessibility, repeatability and cost-effectiveness are advantages of fusion imaging which make it a powerful diagnostic tool for the modern radiologist.

Abstract

Fusion imaging depicts an innovative technique that facilitates combining assets and reducing restrictions of advanced ultrasound and cross-sectional imaging. The purpose of the present retrospective study was to evaluate the role of fusion imaging for assessing hepatic and renal lesions. Between 02/2011–08/2020, 92 patients in total were included in the study, of which 32 patients had hepatic lesions, 60 patients had renal lesions. Fusion imaging was technically successful in all patients. No adverse side effects upon intravenous (i.v.) application of SonoVue^® (Bracco, Milan, Italy) were registered. Fusion imaging could clarify all 11 (100%) initially as indeterminate described hepatic lesions by computed tomography/magnetic resonance imaging (CT/MRI). Moreover, 5/14 (36%) initially suspicious hepatic lesions could be validated by fusion imaging, whereas in 8/14 (57%), malignant morphology was disproved. Moreover, fusion imaging allowed for the clarification of 29/30 (97%) renal lesions initially characterized as suspicious by CT/MRI, of which 19/30 (63%) underwent renal surgery, histopathology revealed malignancy in 16/19 (84%), and benignity in 3/19 (16%). Indeterminate findings could be elucidated by fusion imaging in 20/20 (100%) renal lesions. Its accessibility and repeatability, even during pregnancy and in childhood, its cost-effectiveness, and its excellent safety profile, make fusion imaging a promising instrument for the thorough evaluation of hepatic and renal lesions in the future.

Puumala hantavirus: an imaging review

Puumala virus (PUUV) is the most common hantavirus in Europe. It is known to cause nephropathia epidemica, which is considered a mild type of hemorrhagic fever with renal syndrome. However, it does not only involve the kidneys and is rarely accompanied by symptomatic hemorrhage. We review the imaging abnormalities caused by PUUV infection, from head to pelvis, emphasizing the broad spectrum of possible findings and bringing further support to a previously suggested denomination "Hantavirus disease" that would encompass all clinical manifestations. Although non-specific, knowledge of radiological appearances is useful to support clinically suspected PUUV infection, before confirmation by serology.

Utility of ultrasound after a negative CT abdomen and pelvis in the emergency department

PURPOSE

The purpose of this study is to assess the utility of an abdominal and/or pelvic ultrasound (US) performed within 24 h after a negative CT of the abdomen and pelvis (CTAP) in the emergency department (ED). The secondary endpoint is to assess whether there is a significant increase in length of stay (LOS) in the ED due to immediate US reimaging.

METHOD

We reviewed the imaging reports of 335 patients over the course of 3 years in our ED who had an US within 24 h after a negative CTAP. We then assessed type of US and whether the US showed any acute findings. We also evaluated LOS in the ED.

RESULTS

Out of 335 patients, there were only three US cases suspicious for acute surgical pathology (3/335 or 0.9%). On 30-day clinical follow-up, only one of the three cases was confirmed as cholecystitis on pathology. The most common non-surgical findings on US not initially reported on CTAP were ovarian cysts (29/83) and gallstones (9/83). Additionally, the LOS for patients who received both a CTAP and US was 119 min longer than patients who only received a CTAP.

CONCLUSION

US abdomen and/or pelvis reimaging within 24 h following a negative CTAP is unlikely to change surgical management in the acute setting. US reimaging can still be useful in diagnosing non-surgical pathology, which could serve to explain the patient's pain. US reimaging after negative CTAP is associated with an average increase in the ED LOS.

Free abdominal gas on computed tomography in the emergency department: aetiologies and association between amount of free gas and mortality

INTRODUCTION

Free abdominal gas is an important finding with major clinical implications. However, data on the aetiologies and prognosis of patients with free gas are scarce. Our primary aim was to describe the sources of free abdominal gas on emergency department (ED) computed tomography (CT). The secondary aim was to evaluate the association between the amount of free gas and all-cause mortality.

METHODS

All patients who underwent CT in the ED between February 2012 and February 2019 with free abdominal gas were included in the study. A scoring system was used to assess the amount of free gas: small - gas bubbles; medium - any gas pocket ≤2cm in diameter; large - any gas pocket >2cm. Data were collected from laboratory and clinical assessment regarding the source of free gas and all-cause mortality.

RESULTS

A total of 372 patients had free abdominal gas. Colonic diverticulitis was the most common aetiology among those with a small or medium amount of free gas (81/250 [32.4%] and 12/71 [16.9%] respectively). For patients with a large amount of gas, peptic disease was the most common aetiology (11/51 [21.6%]). Three-quarters of the patients (280/372, 75.2%) had the source of free gas identified during ED admission. Ninety-day mortality rates were 7.2%, 9.9% and 21.6% for patients with small, medium and large amounts of gas respectively (p=0.007).

CONCLUSIONS

Colonic diverticulitis was the most common source of free abdominal gas and peptic disease was the most common cause of a large amount of free gas. Mortality rates correlated with the amount of gas and were significantly higher in patients with a large amount.

The utility of abdominopelvic CT in pregnant patients with abdominal pain and a negative or inconclusive abdominal MRI

Pregnant women with abdominal pain can pose a diagnostic dilemma due to the nonspecific nature of symptoms and the desire to avoid radiation to the conceptus. Many algorithms will suggest ultrasound (US) or Magnetic Resonance Imaging (MRI) as the first-line imaging choice in pregnant women with abdominal pain due to the lack of ionizing radiation. However, these studies can have limitations as well. Abdominopelvic MRI is susceptible to respiratory motion that could cause a study to be nondiagnostic (Zaitsev et al., 2015 [1]). In the current case series, we present 8 pregnant patients with abdominal pain who underwent CT abdomen and pelvis after negative or inconclusive abdominal MRI exams. To our knowledge, this is the only case series that describes CT findings in the pregnant population after negative or inconclusive MRI.

Point-of-Care Ultrasound to Diagnose Colitis in the Emergency Department: A Case Series and Review of the Literature

BACKGROUND

Colitis refers to an inflammatory process of the colon, composed of a variety of different etiologies including inflammatory bowel disease, infectious colitis, ischemic colitis, and allergic colitis. Usually, abdominal computed tomography (CT) is the gold standard in diagnosing the various forms of colitis. However, by the use of point-of-care ultrasound (POCUS), one may occasionally be able to discern wall thickening, pericolic fluid, and adjacent hyperechoic mesenteric fat. One may also see abscesses, fistulae, or ascites.

CASE SERIES

This is a series of 6 patients who had findings consistent with colitis seen on POCUS performed by an emergency physician. These were confirmed by abdominal CT with contrast. Early detection by POCUS was able to lead to a rapid diagnosis and to expedite treatment. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: The ability to detect findings of colitis by POCUS can be quickly learned by the emergency physician with a strong background in basic ultrasound. For many of the different subtypes of colitis, the initial treatment in the emergency department is the same: i.v. antibiotics, i.v. fluids, and "bowel rest" by maintaining the patient in nothing-by-mouth status. For the stable patient with high clinical suspicion of an infectious etiology of colitis, ultrasound can help confirm the diagnosis and rule out other etiologies. This may be especially important in certain populations such as children and young women, where one can avoid a significant amount of radiation being directed toward the pelvic area.

Diagnostic imaging for acute abdominal pain in an Emergency Department in Italy

Imaging plays a key role in the diagnostic work-up of patients with non-traumatic acute abdominal pain (AAP) in emergency department (ED). We aimed to evaluate the use and diagnostic performance of imaging techniques in adult patients with AAP in an ED in Italy. Patients with non-traumatic AAP admitted at the ED of S. Orsola-Malpighi University Hospital of Bologna (Italy) from the 1st to the 30th November 2016 were included. Demographic and clinical data, data on radiological procedures and discharge diagnosis were collected. Sensitivity and specificity for detecting acute diseases were assessed using the discharge diagnosis from the ED as reference standard. Of the 578 patients (female 52.8%, mean age 51.3 years) admitted to the ED for AAP, 433 (74.9%) underwent abdominal imaging. The most frequent techniques used were abdominal plain radiography and ultrasonography (US), performed in 38.4% and 37.9% of patients, respectively, followed by computed tomography (CT) in 28% of patients. Plain radiography yielded a sensitivity of 28% and specificity of 91.1%; the sensitivity increased to 79.4% in patients with small bowel obstruction. Ultrasonography's sensitivity and specificity were 61.8% and 98.4%, respectively; the sensitivity of US reached 85.2% and 90% in patients with acute cholecystitis/biliary colic and urolithiasis, respectively. The sensitivity and specificity of CT were 87.8% and 92.9%, respectively. Plain radiography is still overused in the diagnostic work-up of AAP in ED in Italy, despite its unsatisfactory sensitivity. Ultrasonography and CT has a higher sensitivity and should be used as first-level imaging in most patients.