ACR Appropriateness Criteria® Acute Pancreatitis

Comparison of Computed Tomography/Magnetic Resonance Imaging Characteristics of Acute Pancreatitis Between Cholecystectomy and Non-cholecystectomy Patients

OBJECTIVE

This study aimed to compare computed tomography (CT)/magnetic resonance imaging (MRI) characteristics of acute pancreatitis (AP) between patients with cholecystectomy and non-cholecystectomy and to validate the effect of prior cholecystectomy on the severity of subsequent pancreatitis.

METHODS

This retrospective study included 384 inpatients with AP at our hospital from January 1, 2020 to December 31, 2023. Based on their history of cholecystectomy, the patients were split into cholecystectomy and non-cholecystectomy groups. propensity score matching was applied, considering age and sex, in a 1:3 ratio. Demographic, clinical, laboratory, and CT/MRI parameters of each group were analyzed.

RESULTS

There were 200 (52.1%) males and 184 (47.9%) females, with a mean age of 53.55 ± 13.86 years (range: 18-98 y). Ninety-six patients were in the cholecystectomy group that had previously undergone cholecystectomy, and 288 in the non-cholecystectomy group. Creatinine and C-reactive protein levels were lower in the patients with cholecystectomy than in patients with non-cholecystectomy (P1 = 0.001, P2 = 0.049). In the prevalence of biliary pancreatitis, the cholecystectomy patients are 27.1%, whereas the non-cholecystectomy patients are 45.8% (P = 0.005). The non-cholecystectomy patients had a significantly higher mean CT/MRI severity index score (3.57 ± 1.72 points) than the cholecystectomy group (3.00 ± 1.58 points; P < 0.001). Regarding local complications, In the groups that underwent cholecystectomy and those that did not, the prevalence of acute peripancreatic fluid collection was 40.4% and 21.9%, respectively. (P < 0.001).

CONCLUSIONS

AP following cholecystectomy exhibits unique imaging characteristics. Cholecystectomy reduces the severity and acute peripancreatic fluid collection rate of subsequent pancreatitis on CT/MRI.

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 risk of developing splanchnic vein thrombosis in acute pancreatitis increases 3 days after symptom onset: A systematic review and meta-analysis

BACKGROUND

Splanchnic vein thrombosis is a complication of acute pancreatitis (AP) and is likely often underdiagnosed.

OBJECTIVES

We aimed to understand the time course and risk factors of splanchnic vein thrombosis in the early phase of AP.

METHODS

A systematic search was conducted using the PRISMA guidelines (PROSPERO registration CRD42022367578). Inclusion criteria were appropriate imaging techniques in adult AP patients, studies that reported splanchnic vein thrombosis data from the early phase, and reliable information on the timing of imaging in relation to the onset of pancreatitis symptoms or hospital admission. The proportion of patients with thrombosis with 95% confidence intervals (CI) was calculated using random-effects meta-analyses, and multiple subgroup analyses were performed.

RESULTS

Data from 1951 patients from 14 studies were analyzed. The proportion of patients with splanchnic vein thrombosis within 12 days after symptom onset was 0.13 (CI 0.07-0.23). The occurrence was lowest at 0.06 (CI 0.03-0.1) between 0 and 3 days after symptom onset, and increased fourfold to 0.23 (CI 0.16-0.31) between 3 and 11 days. On hospital admission, the proportion of patients affected was 0.12 (CI 0.02-0.49); it was 0.17 (CI 0.03-0.58) 1-5 days after admission. The prevalence in mild, moderate, and severe AP was 0.15 (CI 0.05-0.36), 0.26 (CI 0.15-0.43), and 0.27 (CI 0.17-0.4), respectively. Alcoholic etiology (0.31, CI 0.13-0.58) and pancreatic necrosis (0.55, CI 0.29-0.78, necrosis above 30%) correlated with increased SVT prevalence.

CONCLUSION

The risk of developing splanchnic vein thrombosis is significant in the early stages of AP and may affect up to a quarter of patients. Alcoholic etiology, pancreatic necrosis, and severity may increase the prevalence of splanchnic vein thrombosis.

Radiomics models of contrast-enhanced computed tomography for predicting the activity and prognosis of acute pancreatitis

BACKGROUND

The modified pancreatitis activity scoring system (mPASS) was proposed to assess the activity of acute pancreatitis (AP) while it doesn't include indicators that directly reflect pathophysiology processes and imaging characteristics.

OBJECTIVES

To determine the threshold of admission mPASS and investigate radiomics and laboratory parameters to construct a model to predict the activity of AP.

METHODS

AP inpatients at institution 1 were randomly divided into training and validation groups based on a 5:5 ratio. AP inpatients at Institution 2 were served as test group. The cutoff value of admission mPASS scores in predicting severe AP was selected to divide patients into high and low level of disease activity group. LASSO was used in screening features. Multivariable logistic regression was used to develop radiomics model. Meaningful laboratory parameters were used to construct combined model.

RESULTS

There were 234 (48 years ± 10, 155 men) and 101 (48 years ± 11, 69 men) patients in two institutions. The threshold of admission mPASS score was 112.5 in severe AP prediction. The AUC of the radiomics model was 0.79, 0.72, and 0.76 and that of the combined model incorporating rad-score and white blood cell were 0.84, 0.77, and 0.80 in three groups for activity prediction. The AUC of the combined model in predicting disease without remission was 0.74.

CONCLUSIONS

The threshold of admission mPASS was 112.5 in predicting severe AP. The model based on CECT radiomics has the ability to predict AP activity. Its ability to predict disease without remission is comparable to mPASS.

CRITICAL RELEVANCE STATEMENT

This work is the first attempt to assess the activity of acute pancreatitis using contrast-enhanced CT radiomics and laboratory parameters. The model provides a new method to predict the activity and prognosis of AP, which could contribute to further management.

KEY POINTS

Radiomics features and laboratory parameters are associated with the activity of acute pancreatitis. The combined model provides a new method to predict the activity and prognosis of AP. The ability of the combined model is comparable to the modified Pancreatitis Activity Scoring System.

Artificial intelligence-based tools with automated segmentation and measurement on CT images to assist accurate and fast diagnosis in acute pancreatitis

OBJECTIVES

To develop an artificial intelligence (AI) tool with automated pancreas segmentation and measurement of pancreatic morphological information on CT images to assist improved and faster diagnosis in acute pancreatitis.

METHODS

This study retrospectively contained 1124 patients suspected for AP and received non-contrast and enhanced abdominal CT examination between September 2013 and September 2022. Patients were divided into training (N = 688), validation (N = 145), testing dataset [N = 291; N = 104 for normal pancreas, N = 98 for AP, N = 89 for AP complicated with PDAC (AP&PDAC)]. A model based on convolutional neural network (MSAnet) was developed. The pancreas segmentation and measurement were performed via eight open-source models and MSAnet based tools, and the efficacy was evaluated using dice similarity coefficient (DSC) and intersection over union (IoU). The DSC and IoU for patients with different ages were also compared. The outline of tumour and oedema in the AP and were segmented by clustering. The diagnostic efficacy for radiologists with or without the assistance of MSAnet tool in AP and AP&PDAC was evaluated using receiver operation curve and confusion matrix.

RESULTS

Among all models, MSAnet based tool showed best performance on the training and validation dataset, and had high efficacy on testing dataset. The performance was age-affected. With assistance of the AI tool, the diagnosis time was significantly shortened by 26.8% and 32.7% for junior and senior radiologists, respectively. The area under curve (AUC) in diagnosis of AP was improved from 0.91 to 0.96 for junior radiologist and 0.98 to 0.99 for senior radiologist. In AP&PDAC diagnosis, AUC was increased from 0.85 to 0.92 for junior and 0.97 to 0.99 for senior.

CONCLUSION

MSAnet based tools showed good pancreas segmentation and measurement performance, which help radiologists improve diagnosis efficacy and workflow in both AP and AP with PDAC conditions.

ADVANCES IN KNOWLEDGE

This study developed an AI tool with automated pancreas segmentation and measurement and provided evidence for AI tool assistance in improving the workflow and accuracy of AP diagnosis.

Updated Review of Radiologic Imaging and Intervention for Acute Pancreatitis and Its Complications

This is a current update on radiologic imaging and intervention of acute pancreatitis and its complications. In this review, we define the various complications of acute pancreatitis, discuss the imaging findings, as well as the timing of when these complications occur. The various classification and scoring systems of acute pancreatitis are summarized. Advantages and disadvantages of the 3 primary radiologic imaging modalities are compared. We then discuss radiologic interventions for acute pancreatitis. These include diagnostic aspiration as well as percutaneous catheter drainage of fluid collections, abscesses, pseudocysts, and necrosis. Recommendations for when these interventions should be considered, as well as situations in which they are contraindicated are discussed. Fortunately, acute pancreatitis usually is mild; however, serious complications occur in 20%, and admission of patients to the intensive care unit (ICU) occurs in over 10%. In this paper, we will focus on the imaging and interventional radiologic aspects for the serious complications and patients admitted to the ICU.

Recurrent acute pancreatitis: a harbinger for irreversible chronic pancreatitis

Recurrent acute pancreatitis is beginning to be recognized as an intermediary stage in the continuous spectrum between acute and chronic pancreatitis. It is crucial to identify this disease stage and intervene with diagnostic and therapeutic modalities to prevent the painful and irreversible condition of chronic pancreatitis. We review the recent advances in diagnosing and managing this important 'call for action' condition.

ACR Appropriateness Criteria® Acute Onset Flank Pain-Suspicion of Stone Disease (Urolithiasis)

Noncontrast CT (NCCT) is the imaging study of choice for initial evaluation of patients with acute onset of flank pain and suspicion of stone disease without known prior stone disease. NCCT can reliably characterize the location and size of an offending ureteral calculus, identify complications, and diagnose alternative etiologies of abdominal pain. Although less sensitive in the detection of stones, ultrasound may have a role in evaluating for signs of obstruction. Radiography potentially has a role, although has been shown to be less sensitive than NCCT. For patients with known disease and recurrent symptoms of urolithiasis, NCCT remains the test of choice for evaluation. In pregnancy, given radiation concerns, ultrasound is recommended as the initial modality of choice with potential role for noncontrast MRI. In scenarios where stone disease suspected and initial NCCT is inconclusive, contrast-enhanced imaging, either with MRI or CT/CT urogram may be appropriate. 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 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 where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Acute pancreatitis: A review of diagnosis, severity prediction and prognosis assessment from imaging technology, scoring system and artificial intelligence

Acute pancreatitis (AP) is a potentially life-threatening inflammatory disease of the pancreas, with clinical management determined by the severity of the disease. Diagnosis, severity prediction, and prognosis assessment of AP typically involve the use of imaging technologies, such as computed tomography, magnetic resonance imaging, and ultrasound, and scoring systems, including Ranson, Acute Physiology and Chronic Health Evaluation II, and Bedside Index for Severity in AP scores. Computed tomography is considered the gold standard imaging modality for AP due to its high sensitivity and specificity, while magnetic resonance imaging and ultrasound can provide additional information on biliary obstruction and vascular complications. Scoring systems utilize clinical and laboratory parameters to classify AP patients into mild, moderate, or severe categories, guiding treatment decisions, such as intensive care unit admission, early enteral feeding, and antibiotic use. Despite the central role of imaging technologies and scoring systems in AP management, these methods have limitations in terms of accuracy, reproducibility, practicality and economics. Recent advancements of artificial intelligence (AI) provide new opportunities to enhance their performance by analyzing vast amounts of clinical and imaging data. AI algorithms can analyze large amounts of clinical and imaging data, identify scoring system patterns, and predict the clinical course of disease. AI-based models have shown promising results in predicting the severity and mortality of AP, but further validation and standardization are required before widespread clinical application. In addition, understanding the correlation between these three technologies will aid in developing new methods that can accurately, sensitively, and specifically be used in the diagnosis, severity prediction, and prognosis assessment of AP through complementary advantages.

Comparison of the imaging and clinical characteristics between Initial and Recurrent Alcoholic Acute Pancreatitis: a retrospective cross-sectional study

MATERIALS

Patients with alcoholic acute pancreatitis in our hospital were recruited from Jan 2019 to July 2022 and divided into IAAP and RAAP groups. All patients underwent Contrast-Enhanced Computerized Tomography (CECT) or Magnetic Resonance Imaging (MRI) after administration. Imaging manifestations, local complications, severity scores on the Modified CT/MR Severity Index (MCTSI/MMRSI), Extrapancreatic Inflammation on CT/MR (EPIC/M), clinical severity [Bedside Index for Severity in Acute Pancreatitis (BISAP) Acute Physiology and Chronic Health Evaluation (APACHE-II)], and clinical prognosis were compared between the two groups.

Results: 166 patients were recruited for this study, including 134 IAAP (male sex 94%) and 32 RAAP patients (male sex 100%). On CECT or MRI, IAAP patients were more likely to develop ascites and Acute Necrosis collection (ANC) than RAAP patients (ascites:87.3%vs56.2%; P = .01; ANC:38%vs18.7%; P < .05). MCTSI/MMRSI and EPIC/M scores were higher in IAAP than in RAAP patients(MCTSI/MMRSI:6.2vs5.2; P < .05; EPIC/M:5.4vs3.8; P < .05).Clinical severity scores (APACHE-II and BISAP), length of stay, and systemic complications [Systemic Inflammatory Response Syndrome (SIRS), respiratory failure] were higher in the IAAP group than in the RAAP group (P < .05). No mortality outcomes were reported in either group while hospitalized.Conclusions: Patients with IAAP had more severe disease than those with RAAP. These results may be helpful for differentiating care paths for IAAP and RAAP, which are essential for management and timely treatment in clinical practice.

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.

Computed tomography characteristics of acute pancreatitis based on different etiologies at different onset times: a retrospective cross-sectional study

BACKGROUND

The clinical characteristics and imaging findings of acute pancreatitis (AP) are different across the various etiologies, the results are conflicting, and their time from symptom onset to imaging varies. The imaging findings of different etiologies at different onset times are unclear. This study aimed to investigate the computed tomography (CT) characteristics of AP based on different etiologies at different onset times.

METHODS

Patients who underwent plain and contrast-enhanced computed tomography (CECT) for the first attack of AP in 3 hospitals (Affiliated Hospital of North Sichuan Medical College, Chinese People's Liberation Army Western Theater General Hospital, and Suining Central Hospital) from 2015 to 2019 were recruited. According to the different etiologies of AP, the patients were divided into 5 subgroups: biliary AP (n=591), alcoholic AP (n=267), hypertriglyceridemic AP (n=258), mixed causes subgroups (n=199), and "other/idiopathic" AP (n=545). According to the time from onset to CT examination (e.g., 1-3, 4-7, 8-14, 15-28, and >28 days), the onset time was divided into 5 respective phases (I-V). The CT characteristics and clinical and laboratory features were retrospectively reviewed and compared among the different etiology subgroups and onset time.

RESULTS

The positive rate of CT findings in AP diagnosis based on CECT was 96.7% (1,860/1,924). Necrotizing pancreatitis (NP) occurred in 33.2% (617/1,860) of AP patients with positive CECT findings. Among patients with NP, local complications and severe AP of the modified CT severity index (MCTSI) increased over time in those with biliary AP from 17.1%, 25.2%, and 20.0% in Phase I to 42.9%, 44.0%, and 39.7% in Phase IV [all P<0.05, 95% confidence interval (CI): 0.15 to 0.52, 0.28 to 0.63, and 0.18 to 0.82, respectively]. In contrast, NP, local complications and severe AP of MCTSI in those with hypertriglyceridemic AP decreased over time from 24.3%, 22.5%, and 22.7% in Phase I to 1.3%, 1.2%, and 1.9% in Phase V (all P<0.05, 95% CI: 3.20 to 181.74, 3.31 to 175.74, and 2.00 to 120.78, respectively).

CONCLUSIONS

The proportion of NP was 33.2% of positive CECT findings. There may be differences in the CT and clinical manifestations of the different etiologies, and those differences may be related to the onset time.

A new logistic regression model for early prediction of severity of acute pancreatitis using magnetic resonance imaging and Acute Physiology and Chronic Health Evaluation II scoring systems

BACKGROUND

The aim of this study was to develop a new model constructed by logistic regression for the early prediction of the severity of acute pancreatitis (AP) using magnetic resonance imaging (MRI) and the Acute Physiology and Chronic Health Evaluation II (APACHE II) scoring system.

METHODS

This retrospective study included 363 patients with AP. The severity of AP was evaluated by MRI and the APACHE II scoring system, and some subgroups of AP severity were constructed based on a combination of these two scoring systems. The length of stay and occurrence of organ dysfunction were used as clinical outcome indicators and were compared across the different subgroups. We combined the MRI and APACHE II scoring system to construct the regression equations and evaluated the diagnostic efficacy of these models.

RESULTS

In the 363 patients, 144 (39.67%) had systemic inflammatory response syndrome (SIRS), 58 (15.98%) had organ failure, and 17 (4.68%) had severe AP. The AP subgroup with a high MRI score and a simultaneously high APACHE II score was more likely to develop SIRS and had a longer hospitalization. The model, which predicted the severity AP by combining extrapancreatic inflammation on magnetic resonance (EPIM) and APACHE II, was successful, with an area under the receiver operating characteristic (ROC) curve (AUC) of 0.912, which was higher than that of any single parameter. Other models that predicted SIRS complications by combining MRI parameters and APACHE II scores were also successful (all P<0.05), and these models based on EPIM and APACHE II scores were superior to other models in predicting outcome.

CONCLUSIONS

The combination of MRI and clinical scoring systems to assess the severity of AP is feasible, and these models may help to develop personalized treatment and management.

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.

ACR Appropriateness Criteria® Epigastric Pain

Epigastric pain can have multiple etiologies including myocardial infarction, pancreatitis, acute aortic syndromes, gastroesophageal reflux disease, esophagitis, peptic ulcer disease, gastritis, duodenal ulcer disease, gastric cancer, and hiatal hernia. This document focuses on the scenarios in which epigastric pain is accompanied by symptoms such as heartburn, regurgitation, dysphagia, nausea, vomiting, and hematemesis, which raise suspicion for gastroesophageal reflux disease, esophagitis, peptic ulcer disease, gastritis, duodenal ulcer disease, gastric cancer, or hiatal hernia. Although endoscopy may be the test of choice for diagnosing these entities, patients may present with nonspecific or overlapping symptoms, necessitating the use of imaging prior to or instead of endoscopy. The utility of fluoroscopic imaging, CT, MRI, and FDG-PET for these indications are discussed. 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.

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.

Multidisciplinary Management of Complicated Pancreatitis: What Every Interventional Radiologist Should Know

Management of acute pancreatitis is challenging in the presence of local complications that include pancreatic and peripancreatic collections and vascular complications. This review, targeted for interventional radiologists, describes minimally invasive endoscopic, image-guided percutaneous, and surgical procedures for management of complicated pancreatitis and provides insight into the procedures' algorithmic application. Local complications are optimally managed in a multidisciplinary team setting that includes advanced endoscopists; pancreatic surgeons; diagnostic and interventional radiologists; and specialists in infectious disease, nutrition, and critical care medicine. Large symptomatic or complicated sterile collections and secondary infected collections warrant drainage or débridement. The drainage is usually delayed for 4-6 weeks unless clinical deterioration warrants early intervention. If collections are accessible by endoscopy, endoscopic procedures are preferred to avoid pancreaticocutaneous fistulas. Image-guided percutaneous drainage is indicated for symptomatic collections that are not accessible for endoscopic drainage or that present in the acute setting before developing a mature wall. Peripancreatic arterial pseudoaneurysms should be embolized before necrosectomy procedures to prevent potentially life-threatening hemorrhage. Surgical procedures are reserved for symptomatic collections that persist despite endoscopic or interventional drainage attempts. Understanding these procedures facilitates their integration by interventional radiologists into the complex longitudinal care of patients with complicated pancreatitis.

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.

Imaging acute pancreatitis

OBJECTIVES

Acute pancreatitis is common; the clinical course of this potentially severe condition varies widely. This paper aims to review the role of different imaging techniques in the management of acute pancreatitis, describe the main imaging findings for this entity, and explain the terms and criteria used to classify them.

CONCLUSIONS

Imaging techniques play a key role in the management of acute pancreatitis, from diagnosis and staging to identifying and treating complications, as well as in determining the underlying causes of the condition. For these reasons, radiologists should know the advantages and limitations of each imaging technique in the evaluation of acute pancreatitis, be familiar with the wide spectrum of imaging findings associated with it, and how to use the specific terminology derived from the Atlanta classification to ensure the standardization and quality of reports.

Ultrasonographic Monitoring in 38 Dogs with Clinically Suspected Acute Pancreatitis

Abdominal ultrasound examinations (AUEs) are commonly used in the diagnostic evaluation of canine acute pancreatitis (AP). The purpose of this retrospective study was to evaluate and monitor the ultrasonographic changes observed in dogs with clinically suspected AP on consecutive AUEs. The study population was constituted by 38 client-owned dogs hospitalized for no less than 48 h from January 2016 to December 2019. Dogs included in this study were suspected of AP based on the clinical examination and abnormal rapid specific canine pancreatic lipase test performed at admission. Dogs were submitted to two AUEs, the first on the first day of hospitalization, and the second between 40–52 h after the first one. Twelve dogs had both AUEs suggestive of AP. Fourteen dogs received an ultrasonographic diagnosis of AP exclusively on the second AUE. Twelve dogs remained negative on both the first and the second AUE. In 26 out of 38 patients the second AUE was suggestive of AP. If a patient is suspected of AP, it is advisable to carry out ultrasonographic monitoring at least within the first 52 h after admission, since ultrasonographic signs of AP may only become observable later after hospitalization.

Utility of ultrasound in acute pancreatitis

Ultrasound plays an essential role in the initial evaluation of patients with suspected or confirmed acute pancreatitis. In addition to evaluation of the pancreatic parenchyma, ultrasound is used for assessment of the gallbladder, biliary tree, peripancreatic tissues, and regional vascular structures. While enlarged and edematous pancreas are classic sonographic features of acute pancreatitis, the pancreas may appear sonographically normal in the setting of acute pancreatitis. Nonetheless, sonographic evaluation in this setting is valuable because assessment for etiologic factors such as gallstones or evidence of biliary obstruction are best performed with ultrasound. Complications of pancreatitis such as peripancreatic fluid collections, venous thrombosis, or arterial pseudoaneurysm can be identified with careful and focused ultrasound examination. Knowledge of various scanning techniques can help to mitigate some of the commonly encountered barriers to sonographic visualization of the pancreas and right upper quadrant structures. Ultrasound can also be used for guidance of percutaneous treatment such as drainage of fluid collections or pseudoaneurysm thrombosis. Difficulty in differentiating edematous from necrotizing pancreatitis can be mitigated with the use of contrast-enhanced ultrasound to assess pancreatic parenchymal enhancement.