Accuracy of MRI compared with ultrasound imaging and selective use of CT to discriminate simple from perforated appendicitis

Hidden Appendicoliths and Their Impact on the Severity and Treatment of Acute Appendicitis

Background/Objectives: In patients diagnosed with uncomplicated acute appendicitis (UAA), the absence of calcified deposits or stones, called appendicoliths, often leads to consideration of non-operative treatment (NOT), despite the notable treatment failure rate associated with this approach. Previous research has indirectly estimated the prevalence of appendicoliths to range between 15% and 38% retrospectively by CT scan, intraoperative palpation, and pathology report, thereby potentially missing certain concrements. Our hypothesis proposes that this reported prevalence significantly underestimates the occurrence of appendicoliths, which could explain the high failure rate of 29% of patients with appendicitis observed with NOT. Methods: In our prospective study, conducted with a cohort of 56 adult patients diagnosed with acute appendicitis (AA), we employed intraoperative extracorporeal incisions of the vermiform appendix, in addition to standard diagnostic methods. Results: Our findings revealed 50% more appendicoliths by intraoperative incision (n = 36, p < 0.001) compared to preoperative imaging (n = 24). Appendicoliths were present in 71.4% (n = 40, p < 0.001) of AA patients. Conclusions: These results suggest that conventional diagnostic procedures plausibly underestimate the actual prevalence of appendicoliths, potentially elucidating the frequent treatment failures observed in NOT approaches applied to patients with UAA.

ACR Appropriateness Criteria® Acute Pelvic Pain in the Reproductive Age Group: 2023 Update

This review focuses on the initial imaging in the reproductive age adult population with acute pelvic pain, including patients with positive and negative beta-human chorionic gonadotropin (β-hCG) levels with suspected gynecological and nongynecological etiology. For all patients, a combination of transabdominal and transvaginal pelvic ultrasound with Doppler is usually appropriate as an initial imaging study. If nongynecological etiology in patients with negative β-hCG is suspected, then CT of the abdomen and pelvis with or without contrast is also usually appropriate. In patients with positive β-hCG and suspected nongynecological etiology, CT of the abdomen and pelvis with contrast and MRI of the abdomen and pelvis without contrast may be appropriate. In patients with negative β-hCG and suspected gynecological etiology, CT of the abdomen and pelvis with contrast, MRI of pelvis without contrast, or MRI of pelvis with and without contrast 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.

Diagnosis and treatment of appendicitis: systematic review and meta-analysis

BACKGROUND

The optimal diagnosis and treatment of appendicitis remains controversial. This systematic review details the evidence and current best practices for the evaluation and management of uncomplicated and complicated appendicitis in adults and children.

METHODS

Eight questions regarding the diagnosis and management of appendicitis were formulated. PubMed, Embase, CINAHL, Cochrane and clinicaltrials.gov/NLM were queried for articles published from 2010 to 2022 with key words related to at least one question. Randomized and non-randomized studies were included. Two reviewers screened each publication for eligibility and then extracted data from eligible studies. Random effects meta-analyses were performed on all quantitative data. The quality of randomized and non-randomized studies was assessed using the Cochrane Risk of Bias 2.0 or Newcastle Ottawa Scale, respectively.

RESULTS

2792 studies were screened and 261 were included. Most had a high risk of bias. Computerized tomography scan yielded the highest sensitivity (> 80%) and specificity (> 93%) in the adult population, although high variability existed. In adults with uncomplicated appendicitis, non-operative management resulted in higher odds of readmission (OR 6.10) and need for operation (OR 20.09), but less time to return to work/school (SMD - 1.78). In pediatric patients with uncomplicated appendicitis, non-operative management also resulted in higher odds of need for operation (OR 38.31). In adult patients with complicated appendicitis, there were higher odds of need for operation following antibiotic treatment only (OR 29.00), while pediatric patients had higher odds of abscess formation (OR 2.23). In pediatric patients undergoing appendectomy for complicated appendicitis, higher risk of reoperation at any time point was observed in patients who had drains placed at the time of operation (RR 2.04).

CONCLUSIONS

This review demonstrates the diagnosis and treatment of appendicitis remains nuanced. A personalized approach and appropriate patient selection remain key to treatment success. Further research on controversies in treatment would be useful for optimal management.

Association Between Antibiotic Redosing Before Incision and Risk of Incisional Site Infection in Children With Appendicitis

OBJECTIVE

To evaluate whether redosing antibiotics within an hour of incision is associated with a reduction in incisional surgical site infection (iSSI) in children with appendicitis.

BACKGROUND

Existing data remain conflicting as to whether children with appendicitis receiving antibiotics at diagnosis benefit from antibiotic redosing before incision.

METHODS

This was a multicenter retrospective cohort study using data from the Pediatric National Surgical Quality Improvement Program augmented with antibiotic utilization and operative report data obtained though supplemental chart review. Children undergoing appendectomy at 14 hospitals participating in the Eastern Pediatric Surgery Network from July 2016 to June 2020 who received antibiotics upon diagnosis of appendicitis between 1 and 6 hours before incision were included. Multivariable logistic regression was used to compare odds of iSSI in those who were and were not redosed with antibiotics within 1 hour of incision, adjusting for patient demographics, disease severity, antibiotic agents, and hospital-level clustering of events.

RESULTS

A total of 3533 children from 14 hospitals were included. Overall, 46.5% were redosed (hospital range: 1.8%-94.4%, P <0.001) and iSSI rates were similar between groups [redosed: 1.2% vs non-redosed: 1.3%; odds ratio (OR) 0.84, (95%,CI, 0.39-1.83)]. In subgroup analyses, redosing was associated with lower iSSI rates when cefoxitin was used as the initial antibiotic (redosed: 1.0% vs nonredosed: 2.5%; OR: 0.38, (95% CI, 0.17-0.84)], but no benefit was found with other antibiotic regimens, longer periods between initial antibiotic administration and incision, or with increased disease severity.

CONCLUSIONS

Redosing of antibiotics within 1 hour of incision in children who received their initial dose within 6 hours of incision was not associated with reduction in risk of incisional site infection unless cefoxitin was used as the initial antibiotic.

Rapid MRI Abdomen for Assessment of Clinically Suspected Acute Appendicitis in the General Adult Population: a Systematic Review

OBJECTIVES

To perform a systematic review on the use of magnetic resonance imaging (MRI) of the abdomen to evaluate clinically suspected appendicitis in the general adult population. We examined the diagnostic accuracy, the reported trends of MRI use, and the factors that affect the utility of MRI abdomen, including study duration and cost-benefits.

METHODS

We conducted a systematic literature search on PubMed, MEDLINE, Embase, Web of Science, and Cochrane Library databases. We enrolled primary studies investigating the use of MRI in diagnosing appendicitis in the general adult population, excluding studies that predominantly reported on populations not representative of typical adult appendicitis presentations, such as those focusing on paediatric or pregnant populations.

RESULTS

Twenty-seven eligible primary studies and 6 secondary studies were included, totaling 2,044 patients from eight countries. The sensitivity and specificity of MRI for diagnosing appendicitis were 96% (95% CI: 93-97%) and 93% (95% CI: 80-98%), respectively. MRI can identify complicated appendicitis and accurately propose alternative diagnoses. The duration of MRI protocols in each primary study ranged between 2.26 and 30 minutes, and only one study used intravenous contrast agents in addition to the non-contrast sequences. Decision analysis suggests significant benefits for replacing computed tomography (CT) with MRI and a potential for cost reduction. Reported trends in MRI usage showed minimal utilisation in diagnostic settings even when MRI was available.

CONCLUSIONS

MRI accurately diagnoses appendicitis in the general adult population and improves the identification of complicated appendicitis or alternative diagnoses compared to other modalities using a single, rapid investigation.

The efficacy of hemoglobin, albumin, lymphocytes, and platelets (HALP) score in signifying acute appendicitis severity and postoperative outcomes

The HALP score, which is a combined index composed of hemoglobin, albumin, lymphocyte, and platelet, is a new indicator showing both inflammation and nutritional status. This study aims to evaluate the relationship of this combined index consisting of simple laboratory values with the degree of appendicitis complication and postoperative results in patients operated on for acute appendicitis. The data of 684 patients operated for acute appendicitis between January 2017 and December 2022 and inclusion criteria were analyzed with a single-center retrospective cross-sectional study design. Using routine laboratory data, patients' HALP scores were divided into two groups as low and high. The cut-off value of the HALP score according to the presence of postoperative complications was determined as < 31.2 by ROC analysis and the ROC curve. Patients were grouped as HALP score cut-off value below (group 1) and above (group 2). Complicated appendicitis and postoperative outcomes were compared to the HALP score groups. According to the cut-off value of the HALP score, 113 (16.5%) of the patients were in Group 1, and 571 (83.5%) were in Group 2. Complications developed in 15 (26%) patients (p < 0.001). Low HALP scores were a significant risk factor for peri-appendicular abscess (OR 29.12 95% CI 12.39-68.43), appendicitis perforation (OR = 20.82 95% 12.67-34.19), gangrenous appendicitis (OR = 35, 54, 95% 13.33-94.77), and postoperative complications (OR = 15.29 95% 7.95-29.41) (p < 0.001). Besides clinical and radiological findings, the HALP score shows the degree of acute appendicitis complication. It can be used as a simple, inexpensive, and easily applicable diagnostic tool.

A Review of Radiological Investigations in Cases of Acute Appendicitis in a Tertiary Care Hospital

INTRODUCTION

Acute appendicitis is the most common non-traumatic surgical emergency and early diagnosis and management are crucial to decrease morbidity and mortality. There is a variety of scoring systems and radiological investigations that have been used in the diagnosis of acute appendicitis. Hence, the aim of this study is to assess the diagnostic approach in patients with suspected appendicitis in a tertiary care hospital, focusing on the radiological burden.

METHODS

This is a cross-sectional study reviewing the electronic and manual medical records of all adult patients admitted with the diagnosis of acute appendicitis between January 2018 and December 2018 in Salmaniya Medical Complex, Manama, Bahrain. A review of the method of diagnosis (clinical, ultrasound, computed tomography, or others) was done, with a comparison to histopathological results in those that underwent surgical intervention to determine sensitivity and specificity.

RESULTS

In the study period, 488 patients were admitted with acute appendicitis; out of these, 461 underwent surgical intervention. A total of 66 CT scans and 148 ultrasounds were conducted for these patients, out of which 57% of ultrasounds and 86% of CT scans accurately diagnosed acute appendicitis based on histopathological diagnosis, resulting in a sensitivity of 65% and 92%, respectively, and a specificity of 56% and 25%, respectively.

CONCLUSION

The most accurate method of diagnosis of acute appendicitis (highest sensitivity) is CT scanning. However, a prospective study with a detailed assessment of complications of appendicitis is recommended.

ACR Appropriateness Criteria® Right Lower Quadrant Pain: 2022 Update

This document focuses on imaging in the adult and pregnant populations with right lower quadrant (RLQ) abdominal pain, including patients with fever and leukocytosis. Appendicitis remains the most common surgical pathology responsible for RLQ abdominal pain in the United States. Other causes of RLQ pain include right colonic diverticulitis, ureteral stone, and infectious enterocolitis. Appropriate imaging in the diagnosis of appendicitis has resulted in decreased negative appendectomy rate from as high as 25% to approximately 1% to 3%. Contrast-enhanced CT remains the primary and most appropriate imaging modality to evaluate this patient population. MRI is approaching CT in sensitivity and specificity as this technology becomes more widely available and utilization increases. Unenhanced MRI and ultrasound remain the diagnostic procedures of choice in the pregnant patient. MRI and ultrasound continue to perform best in the hands of the experts. 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.

Imaging the acute abdomen in pregnancy: a radiological decision-making tool and the role of MRI

Acute abdominal pain in pregnancy poses a significant diagnostic challenge. The differential diagnosis is wide, clinical assessment is difficult, and the use of conventional imaging methods is restricted due to risks to the fetus. This can lead to delay in diagnosis, which increases the risk of maternal and fetal harm. Imaging techniques not involving ionising radiation are preferred. Sonography remains first line, but anatomical visualisation can be limited due to displacement of adjacent structures by the gravid uterus. MRI provides excellent cross-sectional soft-tissue assessment of the abdomen and pelvis, and no study to date has demonstrated significant deleterious effects to the fetus at any gestation; however, there remains a theoretical risk of tissue heating by radiofrequency pulses, and there must be consideration of benefit versus potential risk for any use of magnetic resonance imaging (MRI) in pregnancy. With a limited protocol of sequences, a broad spectrum of pathologies can be evaluated. Computed tomography carries the highest exposure of ionising radiation to the fetus, but may be necessary, particularly in cases of trauma. The patient must be kept informed and any potential risks to the patient and fetus should be clearly explained. We present a radiological decision-making tool to guide choice of imaging and best establish the underlying diagnosis in the acute pregnant abdomen. In addition, using illustrative examples from our practice at a large tertiary centre, we review the advantages and disadvantages of each imaging method, with particular focus on the utility of MRI.

Optimising diagnostics to discriminate complicated from uncomplicated appendicitis: a prospective cohort study protocol

INTRODUCTION

Growing evidence is showing that complicated and uncomplicated appendicitis are two different entities that may be treated differently. A correct diagnosis of the type of appendicitis is therefore essential. The Scoring system of Appendicitis Severity (SAS) combines clinical, laboratory and imaging findings. The SAS rules out complicated appendicitis in 95% (negative predictive value, NPV) and detects 95% (sensitivity) of patients with complicated appendicitis in adults suspected of acute appendicitis. However, this scoring system has not yet been validated externally. In this study, we aim to provide a prospective external validation of the SAS in a new cohort of patients with clinical suspicion of appendicitis. We will optimise the score when necessary.

METHODS AND ANALYSIS

The SAS will be validated in 795 consecutive adult patients diagnosed with acute appendicitis confirmed by imaging. Data will be collected prospectively in multiple centres. The predicted diagnosis based on the SAS score will be compared with the combined surgical and histological diagnosis. Diagnostic accuracy for ruling out complicated appendicitis will be calculated. If the SAS does not reach a sensitivity and NPV of 95% in its present form, the score will be optimised. After optimisation, a second external validation will be performed in a new group of 328 patients. Furthermore, the diagnostic accuracy of the clinical perspective of the treating physician for differentiation between uncomplicated and complicated appendicitis and the patient's preferences for different treatment options will be assessed.

ETHICS AND DISSEMINATION

Ethical approval was granted by the Amsterdam UMC Medical Ethics Committee (reference W19_416 # 19.483). Because of the observational nature of this study, the study does not fall under the scope of the Medical Research Involving Human Subjects Act. Results will be presented in peer-reviewed journals. This protocol is submitted for publication before analysis of the results.

Accuracy of imaging in discriminating complicated from uncomplicated appendicitis in daily clinical practice

BACKGROUND

Radiologic imaging can accurately diagnose acute appendicitis, but little is known about its discriminatory capacity between complicated and uncomplicated appendicitis.

OBJECTIVE

This study aims to investigate the accuracy of imaging in discriminating complicated from uncomplicated appendicitis.

METHODS

Data was used from the prospective, nationwide, observational SNAPSHOT appendicitis database, including patients with suspected acute appendicitis who were planned for an appendectomy. Usage of ultrasound (US), CT, MRI or a combination was recorded. Radiological reports were used to group for complicated or uncomplicated appendicitis. The reference standard was based on operative and pathological findings. Primary outcomes were sensitivity and specificity in discriminating complicated from uncomplicated appendicitis. Secondary outcomes were diagnostic accuracy results per imaging modality and for the subgroups age, BMI, and sex.

RESULTS

Preoperative imaging was performed in 1964 patients. In 1434 patients (73%), only US was used; in 109 (6%) patients, only CT was used; and 421 (21%) patients underwent US followed by CT or MRI. Overall, imaging workup as practiced, following the national guideline, had a poor sensitivity for complicated appendicitis of only 35%, although specificity was as high as 93%. For US, accuracy for complicated appendicitis was higher in children than in adults; sensitivity 41.2% vs. 26.4% and specificity 94.6% vs. 93.4%, respectively, p = 0.003. For relevant subgroups such as age, sex and BMI, no other differences in the discriminatory performance were found.

CONCLUSION

A diagnostic workup with stepwise imaging, using a conditional CT or MRI strategy, poorly discriminates between complicated and uncomplicated appendicitis in daily practice.

Re-Assessment in Patients with Suspected Acute Appendicitis

Background: The effect of diagnosing appendicitis at re-assessment on post-operative outcomes is not clear. This study aims to compare patients diagnosed with appendicitis at initial presentation versus patients who were diagnosed at re-assessment. Patients and Methods: Data from the Dutch SNAPSHOT appendicitis collaborative was used. Patients with appendicitis who underwent appendectomy were included. Effects of diagnosis at re-assessment were compared with diagnosis at initial presentation. Primary outcomes were the proportion of patients with complicated appendicitis and the post-operative complication rate. Results: Of 1,832 patients, 245 (13.4%) were diagnosed at re-assessment. Re-assessed patients had a post-operative complication rate comparable to those diagnosed with appendicitis at initial presentation (15.1% vs. 12.7%; p = 0.29) and no substantial difference was found in the proportion of patients with complicated appendicitis (27.9% vs. 33.5%; p = 0.07). For patients with complicated appendicitis, more post-operative complications were seen if diagnosed at re-assessment than if diagnosed initially (38.2% vs. 22.9%; p = 0.006). Conclusions: For patients in whom appendicitis was not diagnosed at first presentation, but at re-assessment, both the proportion of complicated appendicitis and the post-operative complication rate were comparable to those who were diagnosed with appendicitis at initial presentation. However, re-assessed patients with complicated appendicitis encountered more post-operative complications.

Magnetic resonance imaging (MRI) for diagnosis of acute appendicitis

BACKGROUND

Appendicitis remains a difficult disease to diagnose, and imaging adjuncts are commonly employed. Magnetic resonance imaging (MRI) is an imaging test that can be used to diagnose appendicitis. It is not commonly regarded as a first-line imaging test for appendicitis, but the reported diagnostic accuracy in some studies is equivalent to computed tomography (CT) scans. As it does not expose patients to radiation, it is an attractive imaging modality, particularly in women and children.

OBJECTIVES

The primary objective was to determine the diagnostic accuracy of MRI for detecting appendicitis in all patients. Secondary objectives: To investigate the accuracy of MRI in subgroups of pregnant women, children, and adults. To investigate the potential influence of MRI scanning variables such as sequences, slice thickness, or field of view.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase until February 2021. We searched the references of included studies and other systematic reviews to identify further studies. We did not exclude studies that were unpublished, published in another language, or retrospective.

SELECTION CRITERIA

We included studies that compared the outcome of an MRI scan for suspected appendicitis with a reference standard of histology, intraoperative findings, or clinical follow-up. Three study team members independently filtered search results for eligible studies.

DATA COLLECTION AND ANALYSIS

We independently extracted study data and assessed study quality using the Quality Assessment of Studies of Diagnostic Accuracy - Revised (QUADAS-2) tool. We used the bivariate model to calculate pooled estimates of sensitivity and specificity.

MAIN RESULTS

We identified 58 studies with sufficient data for meta-analysis including a total of 7462 participants (1980 with and 5482 without acute appendicitis). Estimates of sensitivity ranged from 0.18 to 1.0; estimates of specificity ranged from 0.4 to 1.0. Summary sensitivity was 0.95 (95% confidence interval (CI) 0.94 to 0.97); summary specificity was 0.96 (95% CI 0.95 to 0.97). Sensitivity and specificity remained high on subgroup analysis for pregnant women (sensitivity 0.96 (95% CI 0.88 to 0.99); specificity 0.97 (95% CI 0.95 to 0.98); 21 studies, 2282 women); children (sensitivity 0.96 (95% CI 0.95 to 0.97); specificity 0.96 (95% CI 0.92 to 0.98); 17 studies, 2794 children); and adults (sensitivity 0.96 (95% CI 0.93 to 0.97); specificity 0.93 (95% CI 0.80 to 0.98); 9 studies, 1088 participants), as well as different scanning techniques. In a hypothetical cohort of 1000 patients, there would be 12 false-positive results and 30 false-negative results. Methodological quality of the included studies was poor, and the risk of bias was high or unclear in 53% to 83% of the QUADAS-2 domains.

AUTHORS' CONCLUSIONS

MRI appears to be highly accurate in confirming and excluding acute appendicitis in adults, children, and pregnant women regardless of protocol. The methodological quality of the included studies was generally low due to incomplete and low standards of follow-up, so summary estimates of sensitivity and specificity may be biased. We could not assess the impact and direction of potential bias given the very low number of high-quality studies. Studies comparing MRI protocols were few, and although we found no influence of MRI protocol variables on the summary estimates of accuracy, our results do not rule out that some MRI protocols are more accurate than others.

Abdominal fellowship-trained versus generalist radiologist accuracy when interpreting MR and CT for the diagnosis of appendicitis

OBJECTIVES

To compare the diagnostic accuracy of generalist radiologists working in a community setting against abdominal radiologists working in an academic setting for the interpretation of MR when diagnosing acute appendicitis among emergency department patients.

METHODS

This observational study examined MR image interpretation (non-contrast MR with diffusion-weighted imaging and intravenous contrast-enhanced MR) from a prospectively enrolled cohort at an academic hospital over 18 months. Eligible patients had an abdominopelvic CT ordered to evaluate for appendicitis and were > 11 years old. The reference standard was a combination of surgery and pathology results, phone follow-up, and chart review. Six radiologists blinded to clinical information, three each from community and academic practices, independently interpreted MR and CT images in random order. We calculated test characteristics for both individual and group (consensus) diagnostic accuracy then performed Chi-square tests to identify any differences between the subgroups.

RESULTS

Analysis included 198 patients (114 women) with a mean age of 31.6 years and an appendicitis prevalence of 32.3%. For generalist radiologists, the sensitivity and specificity (95% confidence interval) were 93.8% (84.6-98.0%) and 88.8% (82.2-93.2%) for MR and 96.9% (88.7-99.8%) and 91.8% (85.8-95.5%) for CT. For fellowship-trained radiologists, the sensitivity and specificity were 96.9% (88.2-99.5%) and 89.6% (82.8-94%) for MR and 98.4% (90.5-99.9%) and 93.3% (87.3-96.7%) for CT. No statistically significant differences were detected between radiologist groups (p = 1.0, p = 0.53, respectively) or when comparing MR to CT (p = 0.21, p = 0.17, respectively).

CONCLUSIONS

MR is a reliable, radiation-free imaging alternative to CT for the evaluation of appendicitis in community-based generalist radiology practices.

KEY POINTS

• There was no significant difference in MR image interpretation accuracy between generalist and abdominal fellowship-trained radiologists when evaluating sensitivity (p = 1.0) and specificity (p = 0.53). • There was no significant difference in accuracy comparing MR to CT imaging for diagnosing appendicitis for either sensitivity (p = 0.21) or specificity (p = 0.17). • With experience, generalist radiologists enhanced their MR interpretation accuracy as demonstrated by improved interpretation sensitivity (OR 2.89 CI 1.44-5.77, p = 0.003) and decreased mean interpretation time (5 to 3.89 min).

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.

Diagnosis of Uncomplicated and Complicated Appendicitis in Adults

Background:

Diagnostic work-up of acute appendicitis remains challenging. While some guidelines advise to use a risk stratification based on clinical parameters, others use standard imaging in all patients. As non-operative management of uncomplicated appendicitis has been identified as feasible and safe, differentiation between uncomplicated and complicated appendicitis is of paramount importance. We reviewed the literature to describe the optimal strategy for diagnosis of acute appendicitis.

Methods:

A narrative review about the diagnosis of acute appendicitis in adult patients was conducted. Both diagnostic strategies and goals were analyzed.

Results:

For diagnosing acute appendicitis, both ruling in and ruling out the disease are important. Clinical and laboratory findings individually do not suffice, but when combined in a diagnostic score, a better risk prediction can be made for having acute appendicitis. However, for accurate diagnosis imaging seems obligatory in patients suspected for acute appendicitis. Scoring systems combining clinical and imaging features may differentiate between uncomplicated and complicated appendicitis and may enable ruling out complicated appendicitis. Within conservatively treated patients with uncomplicated appendicitis, predictive factors for non-responsiveness to antibiotics and recurrence of appendicitis need to be defined in order to optimize treatment outcomes.

Conclusion:

Standard imaging increases the diagnostic power for both ruling in and ruling out acute appendicitis. Incorporating imaging features in clinical scoring models may provide better differentiation between uncomplicated and complicated appendicitis. Optimizing patient selection for antibiotic treatment of appendicitis may minimize recurrence rates, resulting in better treatment outcomes.

Prognosis of ultrasonographic low-grade pediatric appendicitis treated with supportive care

BACKGROUND

A previous report proposed ultrasonography-based classification as a promising means of predicting pediatric spontaneously resolving appendicitis. The present study investigated the long-term prognosis of supportive care for low-grade appendicitis identified by ultrasonography, defined as an appendix with a smooth submucosal layer irrespective of blood flow or an appendix with an irregular layer and increased blood flow.

METHODS

The present, retrospective cohort study enrolled patients under 16 years of age with acute appendicitis at a children's hospital between October 2010 and September 2016. The inclusion criteria were ultrasonography findings showing an appendix with (1) full visualization, (2) a diameter ≥6 mm, (3) a smooth submucosal layer or an irregular layer with increased blood flow, and (4) no appendiceal mass, abscess, or perforation. The exclusion criteria were: (1) a history of acute appendicitis, (2) antibiotic administration within 72 hours before diagnosis, and (3) antibiotic administration or surgery before supportive care. The primary outcome was the event-free duration, defined as a period of supportive care alone with no additional intervention or recurrence of appendicitis.

RESULTS

One hundred and eighty-two patients were enrolled. The median Alvarado score was 7 (interquartile range, 6-8), and the median follow-up duration in event-free cases was 1,922 days (interquartile range, 1,347-2,614 days). The event-free rate was 75.0%, 67.0%, and 62.5%, at 1, 2, and 5 years, respectively.

CONCLUSION

The long-term, event-free rate exceeded 60% in patients with low-grade appendicitis defined by ultrasonography who received neither surgery nor antibiotic treatment. Most recurrences occurred within 2 years of the initial diagnosis.

Magnetic resonance imaging versus computed tomography and ultrasound for the diagnosis of female pelvic pathology

OBJECTIVES

We sought to determine the diagnostic accuracy of magnetic resonance (MR) imaging compared with computed tomography (CT) and ultrasound (US) when evaluating for five common pelvic pathologies among women presenting to the emergency department (ED) with right lower quadrant abdominal pain.

METHODS

This prospective, single-center study was conducted at an academic ED as a sub-analysis of a direct comparison of the diagnostic accuracy of CT and MR in the evaluation of appendicitis. Patients were eligible for participation in the parent study if they were at least 12 years old and had a CT performed for evaluation of possible appendicitis. In the current study, only female patients who also underwent pelvic US were included. Three radiologists independently interpreted each MR examination specifically for the presence of pelvic pathology, knowing that patients had initially undergone imaging evaluation for possible appendicitis. The determination of an independent expert panel of two radiologists and one emergency physician based on surgical pathology, comprehensive chart review, clinical information, and follow-up phone calls served as the reference standard. Test characteristics of MR, CT, and US were calculated based on this; the main outcome measure was the summary sensitivity and specificity of MR versus CT and US.

RESULTS

Forty-one participants were included with a mean age of 27.6 ± 10.8 years. The MR consensus interpretation had an overall sensitivity and specificity of 57.1% (CI 38.8-75.5%) and 97.2% (CI 94.7-99.6%) respectively, for detecting any of the five pelvic pathologies. By comparison, CT exhibited sensitivity and specificity of 66.7% (CI 50.0-83.5%) and 98.3% (CI 96.4-100.0%) while it was 64.3% (CI 46.5-82.0%) and 97.7% (CI 95.6-99.9%) for US, respectively. No significant differences were identified when comparing these modalities. Overall, Fleiss' kappa interrater reliability value for MR interpretation was 0.75, corresponding to substantial agreement between the three readers.

CONCLUSIONS

In women who might otherwise undergo multiple imaging tests to evaluate gastrointestinal versus pelvic pathologies, our data suggest that MR may be an acceptable first-line imaging test.

Platelet indices in patients with acute appendicitis: a systematic review with meta-analysis

Correlation between blood inflammatory parameters and acute appendicitis (AA) remains controversial. This meta-analysis aims to evaluate whether platelet (PLT) indices including mean platelet volume (MPV), PLT count, and platelet distribution width (PDW) are associated with AA. Pubmed, Embase, and Cochrane Library databases were searched for observational studies published from inception through April 2020 by two independent investigators. Studies reporting associations between platelet indices and AA were selected for inclusion. Standardized mean difference (SMD) and 95% confidence interval (CI) were estimated for continuous outcomes using a DerSimonian-Laird random-effects model. Of 842 records identified, 17 studies with a total of 6793 subjects met our inclusion criteria. Meta-analysis indicated that compared with those in healthy controls, significant decrease in MPV levels was observed in subjects with AA (SMD - 0.34; 95% CI - 0.56 to - 0.12; P = 0.003). Subgroup analyses represented a significant reduction of MPV levels in patients aged ≥ 30 years and non-complicated/non-perforated AA. Due to the small number of studies and patients included in each subgroup, these subgroup analyses need to be interpreted with caution. However, none of the levels of PLT (SMD - 0.13; 95% CI - 0.28-0.012; P = 0.071) or PDW (SMD 0.30; 95% CI - 0.22-0.83; P = 0.257) was seen decrease or increase in subjects with AA. This meta-analysis indicates a significant decrease in MPV levels in patients with AA, which makes MPV have the potential of serving as a biomarker for AA. The associations of other PLT indices with AA need to be further examined.

Discriminating complicated from uncomplicated appendicitis by ultrasound imaging, computed tomography or magnetic resonance imaging: systematic review and meta-analysis of diagnostic accuracy

Background

Discriminating complicated from uncomplicated appendicitis is crucial. Patients with suspected complicated appendicitis are best treated by emergency surgery, whereas those with uncomplicated appendicitis may be treated with antibiotics alone. This study aimed to obtain summary estimates of the accuracy of ultrasound imaging, CT and MRI in discriminating complicated from uncomplicated appendicitis

Methods

A systematic literature review was conducted by an electronic search in PubMed, Embase and the Cochrane Library for studies describing the diagnostic accuracy of complicated versus uncomplicated appendicitis. Studies were included if the population comprised adults, and surgery or pathology was used as a reference standard. Risk of bias and applicability were assessed with QUADAS-2. Bivariable logitnormal random-effect models were used to estimate mean sensitivity and specificity.

Results

Two studies reporting on ultrasound imaging, 11 studies on CT, one on MRI, and one on ultrasonography with conditional CT were included. Summary estimates for sensitivity and specificity in detecting complicated appendicitis could be calculated only for CT, because of lack of data for the other imaging modalities. For CT, mean sensitivity was 78 (95 per cent c.i. 64 to 88) per cent, and mean specificity was 91 (85 to 99) per cent. At a median prevalence of 25 per cent, the positive predictive value of CT for complicated appendicitis would be 74 per cent and its negative predictive value 93 per cent.

Conclusion

Ultrasound imaging, CT and MRI have limitations in discriminating between complicated and uncomplicated appendicitis. Although CT has far from perfect sensitivity, its negative predictive value for complicated appendicitis is high.

Validation of a Scoring System to Distinguish Uncomplicated From Complicated Appendicitis

BACKGROUND

Studies have shown that uncomplicated appendicitis can be treated conservatively with antibiotics. It is important to select only those patients with uncomplicated appendicitis when considering conservative management. Recently, a scoring system based on clinical evaluation and ultrasound was developed to improve this selection and aid in shared decision making when considering an antibiotics-first strategy. The aim of this study was to externally validate the scoring system.

MATERIALS AND METHODS

A retrospective cohort study of all adult patients presenting to the emergency department between January 2014 and January 2017 with suspected acute appendicitis based on clinical evaluation and ultrasound was performed. For every patient, a score was calculated using the previously described scoring system. A final diagnosis, subdivided into complicated appendicitis, uncomplicated appendicitis, complicated alternative disease, and uncomplicated alternative disease, was assigned to every patient based on operative findings.

RESULTS

A total of 678 patients with suspected acute appendicitis based on clinical and ultrasonography findings were identified, of whom 175 (25.8%) had complicated appendicitis, 491 (72.4%) had uncomplicated appendicitis, and 12 (1.8%) had an alternative disease. Of the 678 patients, 272 had a score of five points or less, of whom 17 (6.2%) had complicated appendicitis, giving a negative predictive value of 93.8%.

CONCLUSIONS

With the scoring system based on clinical and ultrasonography features, 93.8% of patients predicted to have uncomplicated appendicitis were correctly identified. The scoring system could help identify patients suitable for conservative management in future studies.

The importance of visualization of appendix on abdominal ultrasound for the diagnosis of appendicitis in children: A quality assessment review

BACKGROUND

Ultrasound has the first line investigation role in the diagnosis of acute appendicitis in children. The purpose of this study was to perform a quality assessment review on the visualization rate of appendix on ultrasound in children in the community hospital setting.

METHODS

A retrospective chart review of the abdominal ultrasound findings for the visualization of the appendix was performed on paediatric patients ranging from 5 to 18 years. Data were collected from the two community hospitals of Toronto by using hospital electronic medical record for the ultrasound findings in patients presented with abdominal pain.

RESULTS

Data from two community hospitals indicated visualization rate of the appendix as 11.0% and 23.2% for site 1 and site 2 respectively. In cases where the ultrasound was repeated the visualization rate remains the same. A two-proportion z-test was performed to find whether the visualization of appendix increases the likelihood of diagnosing appendicitis. The results revealed that the visualization of an appendix (P=0.52), significantly improved the diagnosis of appendicitis (z=34, P<0.001).

CONCLUSION

Visualization of an appendix on ultrasound increases the likelihood of correctly diagnosing appendicitis. In our study, we found low visualization rate of appendix on ultrasound that could be the result of many factors that contribute towards the low visualization rate of an appendix on ultrasound. Hence, the challenges in identifying appendix should be minimized to improve the visualization and diagnosis of appendicitis on ultrasound.

The SIFIPAC/WSES/SICG/SIMEU guidelines for diagnosis and treatment of acute appendicitis in the elderly (2019 edition)

The epidemiology and the outcomes of acute appendicitis in elderly patients are very different from the younger population. Elderly patients with acute appendicitis showed higher mortality, higher perforation rate, lower diagnostic accuracy, longer delay from symptoms onset and admission, higher postoperative complication rate and higher risk of colonic and appendiceal cancer. The aim of the present work was to investigate age-related factors that could influence a different approach, compared to the 2016 WSES Jerusalem guidelines on general population, in terms of diagnosis and management of elderly patient with acute appendicitis. During the XXIX National Congress of the Italian Society of Surgical Pathophysiology (SIFIPAC) held in Cesena (Italy) in May 2019, in collaboration with the Italian Society of Geriatric Surgery (SICG), the World Society of Emergency Surgery (WSES) and the Italian Society of Emergency Medicine (SIMEU), a panel of experts participated to a Consensus Conference where eight panelists presented a number of statements, which were developed for each of the four topics about diagnosis and management of acute appendicitis in elderly patients, formulated according to the GRADE system. The statements were then voted, eventually modified and finally approved by the participants to the Consensus Conference. The current paper is reporting the definitive guidelines statements on each of the following topics: diagnosis, non-operative management, operative management and antibiotic therapy.

Hyponatremia as a marker of complicated appendicitis: A systematic review

BACKGROUND

Acute appendicitis, the most common cause of acute surgical abdomen, is associated with intra-abdominal complications, such as perforation, that increase morbidity and mortality. Early and accurate preoperative diagnosis of complicated appendicitis mandates the identification of new diagnostic markers. This systematic review summarizes current literature on the adoption of hyponatremia as an early diagnostic and predictive marker of complicated appendicitis.

METHODS

Pubmed, Cochrane Library, Scopus, Google Scholar, WHO Global Health Library, System for Information on Grey Literature, ISI Web of Science, EBSCOHost and Virtual Health Library were searched in accordance with the PRISMA guidelines in order to identify original human studies investigating the association between hyponatremia and the presence or development of complicated appendicitis.

RESULTS

A total of 7 studies conducted in 6 different countries were identified. A prospective diagnostic accuracy study reported a strong association between hyponatremia and complicated appendicitis in children. The largest sample size study performed in adults reported a significant association between hyponatremia and perforated or gangrenous appendicitis.

CONCLUSIONS

The admission serum sodium level measurement, a routinely performed, low-cost test, should be taken into account in patients with clinical presentation compatible with acute appendicitis and suspicion of underlying complications. Future well-designed prospective diagnostic accuracy studies are required to further establish the association between hyponatremia and perforated appendicitis.

Diagnostic performance of standardized ultrasound protocol for detecting perforation in pediatric appendicitis

BACKGROUND

Recent clinical trials in adults and children have shown that uncomplicated acute appendicitis can be successfully treated with antibiotics alone. As treatment strategies for acute appendicitis diverge, accurate preoperative diagnosis of complicated appendicitis and appendiceal perforation has become increasingly important for clinical decision-making.

OBJECTIVE

To examine diagnostic performance of ultrasound for detecting perforated appendicitis in a single institution using a standardized technique.

MATERIALS AND METHODS

In this retrospective single-center study we evaluated 113 ultrasounds from pediatric patients who underwent appendectomy between November 2014 and December 2015. All ultrasounds were performed using a standardized US protocol including still and cine images of all four abdominal quadrants, with more targeted evaluation of the right lower quadrant (RLQ) using graded compression technique. We compared US findings to intraoperative diagnosis of non-perforated or perforated acute appendicitis.

RESULTS

The standardized image protocol generated a reproducible set of ultrasound images in all cases. The most common primary appendiceal finding on US in perforated appendicitis was appendix wall thickening >3 mm (54%, 171/314) and most common secondary finding was echogenic mesenteric fat (75%, 237/314). Thinning of the appendix wall and loculated fluid collection in the right lower quadrant were both highly specific (>90%) for perforation.

CONCLUSION

The diagnostic performance of ultrasound using a standardized US technique was similar to that reported in prior studies for detecting perforated appendicitis. Despite low sensitivity, individual ultrasound findings and overall diagnostic impression of "evidence of appendix perforation" remain highly specific.

Falling through the worm hole: an exploration of the imaging workup of the vermiform appendix in the pediatric population

Despite the thousands of articles discussing appendicitis in the literature, the dilemma of how to best diagnosis and manage pediatric appendicitis remains unsettled. Over the past decade, evidence has been mounting about the use of antibiotics as the sole therapy in uncomplicated appendicitis in the adult population. This debate has even recently bled over into the lay press. While this change in practice pattern is still in its infancy for the pediatric population, radiologists should be aware of this change in therapy and how it can impact the imaging work-up and relevant findings. This article concisely summarizes the imaging findings and various imaging pathways to arrive at the diagnose of appendicitis with an emphasis of how to best be of use to our surgical colleagues in this evolving paradigm. It also highlights venues for further research, namely increasing accuracy of differentiating complicated from uncomplicated appendicitis.

Single institutional experience with initial ultrasound followed by computed tomography or magnetic resonance imaging for acute appendicitis in adults

PURPOSE

The objectives of this study was to assess the performance of ultrasound (US) for suspected appendicitis in adult patients and to evaluated the additive value of short-interval (within 1 week) computed tomography (CT) or Magnetic Resonance Imaging (MRI) after performing an initial US.

METHODS

In this IRB-approved, HIPAA-compliant, retrospective study, electronic medical records (EMRs) were queried for "US appendicitis" performed over a 2-year interval. EMR was reviewed for CT or MRI performed within 1 week of this exam, and if any new or additional information was available at subsequent exam. White count, patient disposition, and pathology, if surgery was performed, were also recorded.

RESULTS

682 patients underwent US for appendicitis over a 2-year duration, age range from 18 to 92 years (average: 30.1 years, M:F = 141:541). Findings showed 126/682 patients with normal appendix, 75/682 uncomplicated appendicitis, and 4/682 with complicated appendicitis. When performed, no additional findings were seen in these groups on short-interval CT or MRI. 2/682 patients had equivocal findings on US but eventually had normal appendix identified on CT. Four hundred and seventy-three patients had non-visualized appendix, of which only 14/473 (3.1%) eventually had appendicitis.

CONCLUSIONS

Ultrasound is an effective initial modality for evaluating appendicitis even in adult patients. Once a normal appendix, uncomplicated or complicated appendicitis is identified on US, no further imaging is necessary. Very few patients with non-visualization of the appendix eventually have appendicitis. Hence, these patients can be managed with active clinical follow-up rather than immediate CT or MRI. Symptoms and clinical scoring systems can be used for triage of these patients.

ACR Appropriateness Criteria® Right Lower Quadrant Pain-Suspected Appendicitis

Appendicitis remains the most common surgical pathology responsible for right lower quadrant (RLQ) abdominal pain presenting to emergency departments in the United States, where the incidence continues to increase. Appropriate imaging in the diagnosis of appendicitis has resulted in decreased negative appendectomy rate from as high as 25% to approximately 1% to 3%. Contrast-enhanced CT remains the primary and most appropriate imaging modality to evaluate this patient population. MRI is approaching CT in sensitivity and specificity as this technology becomes more widely available and utilization increases. Unenhanced MRI and ultrasound remain the diagnostic procedures of choice in the pregnant patient. MRI and ultrasound continue to perform best in the hands of experts. 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.

Prospective evaluation of MRI compared with CT for the etiology of abdominal pain in emergency department patients with concern for appendicitis

BACKGROUND

Computed tomography (CT) is commonly used in the Emergency Department (ED) to evaluate patients with abdominal pain, but exposes them to ionizing radiation, a possible carcinogen. MRI does not utilize ionizing radiation and may be an alternative.

PURPOSE

To compare the sensitivity of MRI and CT for acute abdominopelvic ED diagnoses.

STUDY TYPE

Prospective, observational cohort.

POPULATION

ED patients ≥12 years old and undergoing CT for possible appendicitis.

FIELD STRENGTH/SEQUENCE

1.5 T MRI, including T₁ -weighted, T₂ -weighted, and diffusion-weighted imaging sequences.

ASSESSMENT

Three radiologists independently interpreted each MRI and CT image set separately and blindly, using a standard case report form. Assessments included likelihood of appendicitis, presence of an alternative diagnosis, and likelihood that the alternative diagnosis was causing the patient's symptoms. An expert panel utilized chart review and follow-up phone interviews to determine all final diagnoses. Times to complete image acquisition and image interpretation were also calculated.

STATISTICAL TESTS

Sensitivity was calculated for each radiologist and by consensus (≥2 radiologists in agreement) and are reported as point estimates with 95% confidence intervals. Two-sided hypothesis tests comparing the sensitivities of the three image types were conducted using Pearson's chi-squared test with the traditional significance level of P = 0.05.

RESULTS

There were 15 different acute diagnoses identified on the CT/MR images of 113 patients. Using individual radiologist interpretations, the sensitivities of noncontrast-enhanced MRI (NCE-MR), contrast-enhanced MR (CE-MR), and CT for any acute diagnosis were 77.0% (72.6-81.4%), 84.2% (80.4-88.0%), and 88.7% (85.5-92.1%). Sensitivity of consensus reads was 82.0% (74.9-88.9%), 87.1% (81.0-93.2%), 92.2% (87.3-97.1%), respectively. There was no difference in sensitivities between CE-MR and CT by individual (P = 0.096) or consensus interpretations (P = 0.281), although NCE-MR was inferior to CT in both modes of analysis (P < 0.001, P = 0.031, respectively).

DATA CONCLUSION

The sensitivity of CE-MR was similar to CT when diagnosing acute, nontraumatic abdominopelvic pathology in our cohort.

LEVEL OF EVIDENCE

2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:1651-1658.

Perforation risk in pediatric appendicitis: assessment and management

Perforated appendicitis, as defined by a visible hole in the appendix or an appendicolith free within the abdomen, carries significant morbidity in the pediatric population. Accurate diagnosis is challenging as there is no single symptom or sign that accurately predicts perforated appendicitis. Younger patients and those with increased duration of symptoms are at higher risk of perforated appendicitis. Elevated leukocytosis, bandemia, high C-reactive protein, hyponatremia, ultrasound, and CT are all useful tools in diagnosis. Distinguishing patients with perforation from those without is important given the influence of a perforation diagnosis on the management of the patient. Treatment for perforated appendicitis remains controversial as several options exist, each with its indications and merits, illustrating the complexity of this disease process. Patients may be managed non-operatively with antibiotics, with or without interval appendectomy. Patients may also undergo appendectomy early in the course of their index hospitalization. Factors known to predict failure of non-operative management include appendicolith, leukocytosis greater than 15,000 white blood cells per microliter, increased bands, and CT evidence of disease beyond the right lower quadrant. In this review, the indications and benefits of each treatment strategy will be discussed and an algorithm to guide treatment decisions will be proposed.

Antibiotics Versus Appendicectomy for the Treatment of Uncomplicated Acute Appendicitis: An Updated Meta-Analysis of Randomised Controlled Trials

BACKGROUND

Uncomplicated acute appendicitis has been managed traditionally by early appendicectomy. However, recently, there has been increasing interest in the potential for primary treatment with antibiotics, with studies finding this to be associated with fewer complications than appendicectomy. The aim of this study was to compare outcomes of antibiotic therapy with appendicectomy for uncomplicated acute appendicitis.

METHOD

This meta-analysis of randomised controlled trials included adult patients presenting with uncomplicated acute appendicitis treated with antibiotics or appendicectomy. The primary outcome measure was complications. Secondary outcomes included treatment efficacy, hospital length of stay (LOS), readmission rate and incidence of complicated appendicitis.

RESULTS

Five randomised controlled trials with a total of 1430 participants (727 undergoing antibiotic therapy and 703 undergoing appendicectomy) were included. There was a 39 % risk reduction in overall complication rates in those treated with antibiotics compared with those undergoing appendicectomy (RR 0.61, 95 % CI 0.44-0.83, p = 0.002). There was no significant difference in hospital LOS (mean difference 0.25 days, 95 % CI -0.05 to 0.56, p = 0.10). In the antibiotic cohort, 123 of 587 patients initially treated successfully with antibiotics were readmitted with symptoms suspicious of recurrent appendicitis. The incidence of complicated appendicitis was not increased in patients who underwent appendicectomy after "failed" antibiotic treatment (10.8 %) versus those who underwent primary appendicectomy (17.9 %).

CONCLUSION

Increasing evidence supports the primary treatment of acute uncomplicated appendicitis with antibiotics, in terms of complications, hospital LOS and risk of complicated appendicitis. Antibiotics should be prescribed once a diagnosis of acute appendicitis is made or considered.

Creating diagnostic criteria for perforated appendicitis using cross-sectional imaging

INTRODUCTION

Preoperative determination of perforated versus acute appendicitis can be difficult. We compared CT and MRI performance in diagnosing perforated appendicitis, and created diagnostic criteria.

METHODS

We retrospectively reviewed all pediatric patients who underwent appendectomy within one day of CT or MRI between 1/1/2013 and 1/16/2016. True diagnosis was determined by pathology report. Findings on CT/MRI were grouped into "hard" findings (abscess, pneumoperitoneum, extruded fecalith, appendiceal wall with visible hole) and "soft" findings (extensive/diffuse inflammation/free fluid, phlegmon). Correlation of white blood cell count (WBC), temperature, peritoneal signs, and symptom duration >72 h with perforation was assessed using logistic regression. Significant correlates were incorporated in clinical criteria.

RESULTS

135 patients underwent appendectomy after CT/MRI. Fifty patients underwent MRI and 85 CT. Using hard and/or soft findings, MRI was 86.7% sensitive and 74.3% specific, compared to 68.4% (p = 0.19) and 92.4% (p = 0.025) for CT. WBC > 15, temperature >38.0 °C, and peritoneal signs predicted perforation. Diagnostic accuracy of MRI was highest using imaging findings alone. Accuracy of CT was improved by mandating at least one of the previous three clinical correlates, resulting in 68.4% sensitivity and 93.9% specificity.

CONCLUSIONS

MRI trended toward more sensitive and CT was more specific for complicated appendicitis. CT specificity is improved by our algorithm.

Magnetic Resonance Imaging Versus Ultrasound as the Initial Imaging Modality for Pediatric and Young Adult Patients With Suspected Appendicitis

BACKGROUND

While ultrasound (US), given its lack of ionizing radiation, is currently the recommended initial imaging study of choice for the diagnosis of appendicitis in pediatric and young adult patients, it does have significant shortcomings. US is time-intensive and operator dependent and results in frequent inconclusive studies, thus necessitating further imaging and admission for observation or repeat clinical visits. A rapid focused magnetic resonance imaging (MRI) for appendicitis has been shown to have definitive sensitivity and specificity, similar to computed tomography but without radiation and offers a potential alternative to US.

OBJECTIVE

In this single-center prospective cohort study, we sought to determine the difference in total length of stay and charges between rapid MRI and US as the initial imaging modality in pediatric and young adult patients presenting to the emergency department (ED) with suspected appendicitis. We hypothesized that rapid MRI would be more efficient and cost-effective than US as the initial imaging modality in the ED diagnosis of appendicitis.

METHODS

A prospective randomized cohort study of consecutive patients was conducted in patients 2 to 30 years of age in an academic ED with access to both rapid MRI and US imaging modalities 24/7. Prior to the start of the study, the days of the week were randomized to either rapid MRI or US as the initial imaging modality. Physicians evaluated patients with suspected appendicitis per their usual manner. If the physician decided to obtain radiologic imaging, the predetermined imaging modality for the day of the week was used. All decisions regarding other diagnostic testing and/or further imaging were left to the physician's discretion. Time intervals (minutes) between triage, order placement, start of imaging, end of imaging, image result, and disposition (discharge vs. admission), as well as total charges (diagnostic testing, imaging, and repeat ED visits) were recorded.

RESULTS

Over a 100-day period, 82 patients were imaged to evaluate for appendicitis; 45 of 82 (55%) of patients were in the US-first group, and 37 of 82 (45%) patients were in the rapid MRI-first group. There were no differences in patient demographics or clinical characteristics between the groups and no cases of missed appendicitis in either group. Eleven of 45 (24%) of US-first patients had inconclusive studies, resulting in follow-up rapid MRI and five return ED visits contrasted with no inconclusive studies or return visits (p < 0.05) in the rapid MRI group. The rapid MRI compared to US group was associated with longer ED length of stay (mean difference = 100 minutes; 95% confidence interval [CI] = 35-169 minutes) and increased ED charges (mean difference = $4,887; 95% CI = $1,821-$8,513).

CONCLUSIONS

In the diagnosis of appendicitis, US-first imaging is more time-efficient and less costly than rapid MRI despite inconclusive studies after US imaging. Unless the process of obtaining a rapid MRI becomes more efficient and less expensive, US should be the first-line imaging modality for appendicitis in patients 2 to 30 years of age.

Preparation and Characterization of Novel Perfluorooctyl Bromide Nanoparticle as Ultrasound Contrast Agent via Layer-by-Layer Self-Assembly for Folate-Receptor-Mediated Tumor Imaging

A folate-polyethylene glycol-chitosan derivative was synthesized and its structure was characterized. An optimal perfluorooctyl bromide nanocore template was obtained via utilizing the ultrasonic emulsification method combining with orthogonal design. The targeted nanoparticles containing targeted shell of folate-polyethylene glycol-chitosan derivative and perfluorooctyl bromide nanocore template of ultrasound imaging were prepared successfully by exploiting layer-by-layer self-assembly as contrast agent for ultrasound. Properties of the novel perfluorooctyl bromide nanoparticle were extensively studied by Dynamic Light Scattering and Transmission Electron Microscopy. The targeted nanoparticle diameter, polydispersity, and zeta potential are around 229.5 nm, 0.205, and 44.7 ± 0.6 mV, respectively. The study revealed that spherical core-shell morphology was preserved. Excellent stability of targeted nanoparticle is evidenced by two weeks of room temperature stability tests. The results of the cell viability assay and the hemolysis test confirmed that the targeted nanoparticle has an excellent biocompatibility for using in cell studies and ultrasound imaging in vivo. Most importantly, in vitro cell experiments demonstrated that an increased amount of targeted nanoparticles was accumulated in hepatocellular carcinoma cell line Bel7402 relative to hepatoma cell line L02. And targeted nanoparticles had also shown better ultrasound imaging abilities in vitro. The data suggest that the novel targeted nanoparticle may be applicable to ultrasonic molecular imaging of folate-receptor overexpressed tumor.

WSES Jerusalem guidelines for diagnosis and treatment of acute appendicitis

Acute appendicitis (AA) is among the most common cause of acute abdominal pain. Diagnosis of AA is challenging; a variable combination of clinical signs and symptoms has been used together with laboratory findings in several scoring systems proposed for suggesting the probability of AA and the possible subsequent management pathway. The role of imaging in the diagnosis of AA is still debated, with variable use of US, CT and MRI in different settings worldwide. Up to date, comprehensive clinical guidelines for diagnosis and management of AA have never been issued. In July 2015, during the 3rd World Congress of the WSES, held in Jerusalem (Israel), a panel of experts including an Organizational Committee and Scientific Committee and Scientific Secretariat, participated to a Consensus Conference where eight panelists presented a number of statements developed for each of the eight main questions about diagnosis and management of AA. The statements were then voted, eventually modified and finally approved by the participants to The Consensus Conference and lately by the board of co-authors. The current paper is reporting the definitive Guidelines Statements on each of the following topics: 1) Diagnostic efficiency of clinical scoring systems, 2) Role of Imaging, 3) Non-operative treatment for uncomplicated appendicitis, 4) Timing of appendectomy and in-hospital delay, 5) Surgical treatment 6) Scoring systems for intra-operative grading of appendicitis and their clinical usefulness 7) Non-surgical treatment for complicated appendicitis: abscess or phlegmon 8) Pre-operative and post-operative antibiotics.

Trends in the Use of Medical Imaging to Diagnose Appendicitis at an Academic Medical Center

OBJECTIVE

To quantify the trends in imaging use for the diagnosis of appendicitis.

METHODS

A retrospective study covering a 22-year period was conducted at an academic medical center. Patients were identified by International Classification of Diseases-9 diagnosis code for appendicitis. Medical record data extraction of these patients included imaging test used (ultrasound, CT, or MRI), gender, age, and body mass index (BMI). The proportion of patients undergoing each scan was calculated by year. Regression analysis was performed to determine whether age, gender, or BMI affected imaging choice.

RESULTS

The study included a total of 2,108 patients, including 967 (43.5%) females and 599 (27%) children (<18 years old). CT use increased over time for the entire cohort (2.9% to 82.4%, P < .0001), and each subgroup (males, females, adults, children; P < .0001 for each). CT use increased more in females and adults than in males and children, but differences in trends were not statistically significant (male versus female, P = .8; adult versus child, P = .1). The percentage of patients who had no imaging used for the diagnosis of appendicitis decreased over time (P < .0001 overall and for each subgroup), and no difference was found in trends between complementary subgroups (male versus female, P = .53; adult versus child, P = .66). No statistically significant changes were found in use of ultrasound or MRI over the study period. With increasing BMI, CT was more frequently used.

CONCLUSIONS

Of those diagnosed with appendicitis at an academic medical center, CT use increased more than 20-fold. However, no statistically significant trend was found for increased use of ultrasound or MRI.

Meta-analysis of antibiotics versus appendicectomy for non-perforated acute appendicitis

Background

For more than a century, appendicectomy has been the treatment of choice for appendicitis. Recent trials have challenged this view. This study assessed the benefits and harms of antibiotic therapy compared with appendicectomy in patients with non‐perforated appendicitis.

Methods

A comprehensive search was conducted for randomized trials comparing antibiotic therapy with appendicectomy in patients with non‐perforated appendicitis. Key outcomes were analysed using random‐effects meta‐analysis, and the quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

Results

Five studies including 1116 patients reported major complications in 25 (4·9 per cent) of 510 patients in the antibiotic and 41 (8·4 per cent) of 489 in the appendicectomy group: risk difference −2·6 (95 per cent c.i. –6·3 to 1·1) per cent (low‐quality evidence). Minor complications occurred in 11 (2·2 per cent) of 510 and 61 (12·5 per cent) of 489 patients respectively: risk difference −7·2 (−18·1 to 3·8) per cent (very low‐quality evidence). Of 550 patients in the antibiotic group, 47 underwent appendicectomy within 1 month: pooled estimate 8·2 (95 per cent c.i. 5·2 to 11·8) per cent (high‐quality evidence). Within 1 year, appendicitis recurred in 114 of 510 patients in the antibiotic group: pooled estimate 22·6 (15·6 to 30·4) per cent (high‐quality evidence). For every 100 patients with non‐perforated appendicitis, initial antibiotic therapy compared with prompt appendicectomy may result in 92 fewer patients receiving surgery within the first month, and 23 more experiencing recurrent appendicitis within the first year.

Conclusion

The choice of medical versus surgical management in patients with clearly uncomplicated appendicitis is value‐ and preference‐dependent, suggesting a change in practice towards shared decision‐making is necessary.

Limitations of each evolving

Acute appendicitis: modern understanding of pathogenesis, diagnosis, and management

Acute appendicitis is one of the most common abdominal emergencies worldwide. The cause remains poorly understood, with few advances in the past few decades. To obtain a confident preoperative diagnosis is still a challenge, since the possibility of appendicitis must be entertained in any patient presenting with an acute abdomen. Although biomarkers and imaging are valuable adjuncts to history and examination, their limitations mean that clinical assessment is still the mainstay of diagnosis. A clinical classification is used to stratify management based on simple (non-perforated) and complex (gangrenous or perforated) inflammation, although many patients remain with an equivocal diagnosis, which is one of the most challenging dilemmas. An observed divide in disease course suggests that some cases of simple appendicitis might be self-limiting or respond to antibiotics alone, whereas another type often seems to perforate before the patient reaches hospital. Although the mortality rate is low, postoperative complications are common in complex disease. We discuss existing knowledge in pathogenesis, modern diagnosis, and evolving strategies in management that are leading to stratified care for patients.