Sonography in the evaluation of acute appendicitis: are negative sonographic findings good enough?

Evaluating the Diagnostic Efficacy of Computed Tomography in Appendicitis Cases With Negative Ultrasound Findings

INTRODUCTION

Acute appendicitis (AA) is a prevalent cause of abdominal pain, and accurate diagnosis is critical to prevent complications such as perforation. While ultrasound (USG) is often the first imaging modality, its limitations necessitate alternative approaches, particularly in cases where USG results are negative.

OBJECTIVES AND AIMS

This study aims to evaluate the diagnostic accuracy of computed tomography (CT) in identifying appendicitis in patients presenting with negative USG findings.

MATERIALS AND METHODS

A prospective observational study was conducted at a tertiary care hospital in Pondicherry, India, involving 70 patients with clinically suspected appendicitis and negative USG results. All patients underwent CT imaging, and findings were analyzed to determine sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall accuracy.

RESULTS

Of the 70 patients, 35 were diagnosed with appendicitis based on CT findings, yielding a sensitivity of 100%, a specificity of 65.71%, a PPV of 74.47%, an NPV of 100%, and an overall accuracy of 82.86%. The study also identified other conditions, such as mesenteric lymphadenitis and ureteric calculus, in patients with negative appendicitis diagnoses.

CONCLUSIONS

CT is a highly effective imaging modality for diagnosing appendicitis in patients with negative USG results. The use of CT significantly aids in clinical decision-making, reducing the rates of unnecessary surgeries and complications.

Can Ultrasound Spot the Culprit - Evaluating the Effectiveness of Ultrasonography in Precisely Diagnosing Acute Appendicitis in Children

Introduction

Acute appendicitis is a common surgical emergency in children, often requiring imaging for confirmation due to diverse presentations. While computed tomography scan is favored in many centers for its sensitivity, it comes with radiation exposure and higher costs. Ultrasonography, being radiation-free and cost-effective, is gaining popularity, especially in pediatric cases. However, its reported accuracy varies in the literature. This study aims to evaluate the diagnostic accuracy of ultrasonography in pediatric appendicitis cases and to determine its precision in distinguishing between simple and complicated cases of appendicitis.

Materials and Methods

A retrospective analysis was conducted on children with suspected appendicitis who presented to the department of pediatric surgery. All patients underwent ultrasonography followed by appendicectomy based on considered clinical decision. Ultrasonography findings were compared with intraoperative observations categorized as uncomplicated or complicated appendicitis.

Results

Among 152 patients, ultrasonography accurately diagnosed appendicitis in 94.6% of cases, with 5.38% having nonvisualized appendices. In our group, the sensitivity and specificity of ultrasound to detect appendicitis were 94.62% and 95.65%, respectively. The diagnostic accuracy of the test is 95.63%. However, in our study, the sensitivity of the ultrasonography to correctly identify if it is a simple or complicated appendicitis was only 54.9% but had a specificity of 98.7%. Thus, ultrasonography showed a much lower sensitivity (54.9%) in distinguishing between simple and complicated appendicitis.

Conclusion

Ultrasonography demonstrates high sensitivity and specificity in diagnosing pediatric appendicitis, making it a promising preoperative investigation. However, it may not accurately differentiate between simple and complicated cases. A comprehensive approach involving clinical and laboratory parameters alongside secondary imaging may be necessary for accurate diagnosis, especially in cases of perforated appendicitis.

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.

Two-dimensional shear wave elastography can improve the diagnostic accuracy of ultrasonography in acute appendicitis

AIM

We aimed to evaluate the effectiveness of combining 2-dimensional shear wave elastography (2D-SWE) with ultrasonography (US) in diagnosing acute appendicitis in patients with suspected acute appendicitis.

METHODS

Clinical and laboratory findings, gray-scale US and 2D-SWE imaging features, operation information, and pathology results of 48 patients diagnosed with acute appendicitis who presented with right lower quadrant pain were prospectively evaluated. We compared the findings to the US and SWE imaging features of 79 asymptomatic patients.

RESULTS

Mean Alvarado score and appendix diameter were statistically significantly higher for acute appendicitis (p < 0.001). In patients with acute appendicitis, mesenteric lymphadenopathy and fat stranding were also more frequent (p < 0.001). The mean velocity and kPa values for appendix and mesenteric fat were statistically significantly higher in acute appendicitis (p < 0.001).

CONCLUSION

In the diagnosis of acute appendicitis, 2D-SWE increases the diagnostic performance of gray-scale US in the differentiation of inflamed and normal appendixes.

The Prognostic Value of Ultrasound Findings in Preoperatively Distinguishing between Uncomplicated and Complicated Types of Pediatric Acute Appendicitis Based on Correlation with Intraoperative and Histopathological Findings

OBJECTIVE

This study compares the preoperative ultrasound findings of all children with a clinical picture of acute appendicitis on the basis of intraoperative and histopathological findings to assess the feasibility of this approach in preoperatively distinguishing between uncomplicated and complicated cases.

METHODS

This retrospective study includes 224 pediatric patients who underwent ultrasound prior to appendectomy at our institution between January 2016 and February 2022. Logistic regression analysis was used to investigate the association between sonographic and intraoperative histopathological findings.

RESULTS

Of the 224 participants, 61.1% were intraoperatively diagnosed with uncomplicated appendicitis (59.8% male). Multivariate logistic regression analysis revealed that patients with a higher appendiceal diameter, presence of appendicolith, and peritonitis were more likely to suffer from complicated appendicitis. Finally, the common anatomical position of the appendix and an appendiceal diameter greater than 6 mm had the highest sensitivity (94.6% and 94.5%, respectively) for predicting complicated appendicitis, with the most specific (99.3%) sonographic finding being the existence of an abscess.

CONCLUSIONS

Preoperative abdominal ultrasound in children with a clinical diagnosis of acute appendicitis can distinguish between uncomplicated and complicated appendicitis in most cases of pediatric appendicitis. A higher appendiceal diameter, the presence of appendicolith, and peritonitis are parameters noted by ultrasound that strongly predict complicated appendicitis.

Diagnostic accuracy of computed tomography and ultrasound for the diagnosis of acute appendicitis: A systematic review and meta-analysis

INTRODUCTION

The diagnosis of acute appendicitis remains challenging. This review determined the current diagnostic accuracy of CT and ultrasound for suspected acute appendicitis in adults.

METHODS

This systematic review adhered to the PRISMA for diagnostic test accuracy guidelines. A systematic search was undertaken in appropriate databases. Screening of potential titles and abstracts, full-text retrieval, methodological quality assessment using QUADAS, and data extraction was performed. Meta-analyses were performed for relevant subgroups, and sensitivity analysis was completed to account for outliers. GRADE was utilized to assess the certainty of findings.

RESULTS

31 studies evaluating CT, 10 evaluating US, and six evaluating both were included. Pooled sensitivity and specificity for CT was 0.972 [0.958, 0.981] and 0.956 [0.941, 0.967] respectively, and 0.821 [0.738, 0.882] and 0.859 [0.727, 0.933] for US, respectively. When analyzing subgroups based on the use of contrast enhancement, sensitivity and specificity was highest for CT with intravenous and oral contrast (0.992 [0.965, 0.998], 0.974 [0.936, 0.99]), compared to CT with intravenous contrast (0.955 [0.922, 0.974], 0.942 [0.916, 0.960]). Low-Dose CT produced comparable values (0.934 [0.885,0.963], 0.937 [0.911, 0.955]) relative to these subgroups and standard dose non-contrast CT (0.877 [0.774,0.937], 0.914 [0.827, 0.959]). US studies which excluded equivocal findings demonstrated significantly greater values than the remainder of US studies (p < 0.0001).

CONCLUSION

The updated diagnostic test accuracies of CT, US and relevant subgroups should be implemented in light of factors such as dose, cost, and timing.

IMPLICATIONS FOR PRACTICE

For diagnosis of adult acute appendicitis: • CT with intravenous plus oral contrast enhancement yields statistically significantly greater diagnostic accuracy than CT with intravenous contrast alone. • Low-dose CT yields comparable sensitivity and specificity to standard-dose CT. • Ultrasound studies which exclude equivocal results may overinflate sensitivity and specificity.

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.

Ultrasound features and the diagnostic strategy of subhepatic appendicitis

Background

This study aimed to compare the differences of ultrasound findings between subhepatic appendicitis and appendicitis at a normal position, then discuss the diagnostic strategies and improve the accuracy of diagnosis.

Methods

A retrospective analysis was performed in our hospital. One thousand five hundred ninety-one patients with appendicitis were diagnosed from January 2014 to January 2018. Eighteen patients with subhepatic appendicitis and 25 patients with appendicitis with regular positions were selected randomly as the control group. The difference in ultrasound features between the two groups was studied. Comparisons between the two groups showed statistically significant differences in the frequencies of the fishbone sign, enlarged appendix, appendicoliths, and hyperechoic omental cap (P<0.05).

Results

Statistical significance was not observed with the difference in the frequency of whether there was lymphadenectasis (P>0.05) in the abdominal cavity between the two groups. The Pareto chart was drawn to look for the main factors associated. The results of interpretation on the critical points of diagnosis for subhepatic appendicitis: (I) the fishbone sign of a dilated ileum in the right lower abdomen; and (II) the fishbone sign of a dilated ileum in the right lower abdomen + presence of an enlarged appendix in the right upper abdomen.

Conclusions

An abnormally dilated ileum in the right lower abdomen – the fishbone sign, is a vital sign leading to the diagnosis of subhepatic appendicitis. The fishbone sign of a dilated ileum in the right lower abdomen + whether there is a vermiform structure is an important diagnostic indicator for subhepatic appendicitis.

Imaging Findings of Gastrointestinal Emergency in Infants and Young Children

급성 복증(acute abdomen)은 갑자기 발생하는 심한 복부 통증으로 즉각적인 수술적 치료를 필요로 할 수도 있는 상태를 말한다. 소아 환자의 급성 복증의 원인은 다양하며, 수술적 치료를 해야 하는 질환부터 투약 치료를 받아야 하거나 임상적 관찰 만을 요하는 질환까지 다양하게 분류될 수 있다. 이러한 급성 복증의 환자에서 영상 검사의 역할은 가능하다면 복통의 원인이 되는 질환을 밝혀서 수술적 치료를 해야 하는 환자와 투약 치료를 해야 하는 환자를 구분해 주는 것이다. 장중첩증과 충수돌기염이 소아 환자에서 수술적 치료를 필요로 하는 급성 복증의 가장 흔한 원인 질환이므로, 급성 복통을 호소하는 영아에서는 장중첩증을, 좀 더 나이가 많은 소아에서는 충수돌기염을 영상 검사를 이용해 배제해 주는 것이 중요하다. 이 논문에서는 영유아 환자의 급성 복통을 유발할 수 있는 질환 중 특징적 영상 소견을 보이는 장중첩증, 충수돌기염, 중장 염전, 메켈 게실 및 중복낭종에 대해 소개하고자 한다

Increased Renal Echogenicity in Children With Appendicitis

OBJECTIVES

Ultrasound (US) is an important modality for the detection of acute appendicitis in children but has limited sensitivity and specificity. Therefore, additional US findings may contribute to the diagnosis. In our experience, children with acute appendicitis often have increased renal cortical echogenicity on US imaging. The purpose of this study was to examine the association of increased renal cortical echogenicity with appendicitis.

METHODS

This study included 240 consecutive pediatric patients with no renal or liver disease who underwent US examinations for suspected appendicitis between February 2014 and January 2016. Ultrasound images of the liver and right kidney were retrospectively reviewed, and the echogenicity of the renal cortex was classified as less than the liver, equal to the liver, or greater than the liver.

RESULTS

The renal cortex was abnormally hyperechoic in 38 (50%) of all of the patients who had appendicitis according to US (P < .001) and in 47% of patients who underwent appendectomy (P = .002). Overall, 36% of patients with increased renal cortical echogenicity had a diagnosis of appendicitis. After correction for variables, patients with renal hyperechogenicity had a 2.5 times chance of appendicitis (odds ratio, 2.5).

CONCLUSIONS

There is a statistically significant association between increased renal cortical echogenicity and appendicitis. In the absence of hepatic or renal disease, this finding may increase the accuracy of the US diagnosis of appendicitis. Increased renal cortical echogenicity may be added to the list of US findings accompanying acute appendicitis in children.

Sonographically detected free appendicolith as a sign of retrocecal perforated appendicitis in a 2-year-old child

Prompt and accurate diagnosis of perforated appendicitis is crucial for proper and timely treatment. The appendix, however, cannot always be identified with sonography (US). We report the case of a 2-year-old child with atypical clinical presentation, and US detection of a free appendicolith as a sign of perforated appendicitis, without visualization of the appendix itself. Laparoscopy revealed a retrocecal, gangrenous, perforated appendix with autoamputation, fibrinopurulent peritonitis, and a free appendicolith within the abdominal fluid. US detection of a free appendicolith in a child is a very rare, but unequivocal sign of perforated appendicitis, which should be sought. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:395-398, 2016.

Imaging in acute appendicitis: What, when, and why?

Acute appendicitis (AA) is the commonest cause of pain abdomen requiring surgical intervention. Diagnosis as well as management of acute appendicitis is mired in controversies and contradictions even today. Clinicians often face the dilemma of balancing negative appendectomy rate and perforation rate if the diagnosis is based on clinical scoring alone. Laboratory results are often non-specific. Imaging has an important role not only in diagnosing appendicitis and its complication but also suggesting alternate diagnosis in appropriate cases. However, there is no universally accepted diagnostic imaging algorithm for appendicitis. Imaging of acute appendicitis needs to be streamlined keeping pros and cons of the available investigative modalities. Radiography has practically no role today in the diagnosis and management of acute appendicitis. Ultrasonography (USG) should be the first line imaging modality for all ages, particularly for children and non-obese young adults including women of reproductive age group. If USG findings are unequivocal and correlate with clinical assessment, no further imaging is needed. In case of equivocal USG findings or clinico-radiological dissociation, follow-up/further imaging (computed tomography (CT) scan/magnetic resonance imaging (MRI)) is recommended. In pediatric and pregnant patients with inconclusive initial USG, MRI is the next option. Routine use of CT scan for diagnosis of AA needs to be discouraged. Our proposed version of a practical imaging algorithm, with USG first and always has been incorporated in the article.

Development and validation of an ultrasound scoring system for children with suspected acute appendicitis

BACKGROUND

To facilitate consistent, reliable communication among providers, we developed a scoring system (Appy-Score) for reporting limited right lower quadrant ultrasound (US) exams performed for suspected pediatric appendicitis.

OBJECTIVE

The purpose of this study was to evaluate implementation of this scoring system and its ability to risk-stratify children with suspected appendicitis.

MATERIALS AND METHODS

In this HIPAA compliant, Institutional Review Board-approved study, the Appy-Score was applied retrospectively to all limited abdominal US exams ordered for suspected pediatric appendicitis through our emergency department during a 5-month pre-implementation period (Jan 1, 2013, to May 31, 2013), and Appy-Score use was tracked prospectively post-implementation (July 1, 2013, to Sept. 30,2013). Appy-Score strata were: 1 = normal completely visualized appendix; 2 = normal partially visualized appendix; 3 = non-visualized appendix, 4 = equivocal, 5a = non-perforated appendicitis and 5b = perforated appendicitis. Appy-Score use, frequency of appendicitis by Appy-Score stratum, and diagnostic performance measures of US exams were computed using operative and clinical finding as reference standards. Secondary outcome measures included rates of CT imaging following US exams and negative appendectomy rates.

RESULTS

We identified 1,235 patients in the pre-implementation and 686 patients in the post-implementation groups. Appy-Score use increased from 24% (37/155) in July to 89% (226/254) in September (P < 0.001). Appendicitis frequency by Appy-Score stratum post-implementation was: 1 = 0.5%, 2 = 0%, 3 = 9.5%, 4 = 44%, 5a = 92.3%, and 5b = 100%. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 96.3% (287/298), 93.9% (880/937), 83.4% (287/344), and 98.8% (880/891) pre-implementation and 93.0% (200/215), 92.6% (436/471), 85.1% (200/235), and 96.7% (436/451) post-implementation - only NPV was statistically different (P = 0.012). CT imaging after US decreased by 31% between pre- and post-implementation, 8.6% (106/1235) vs. 6.0% (41/686); P = 0.048). Negative appendectomy rates did not change (4.4% vs. 4.1%, P = 0.8).

CONCLUSION

A scoring system and structured template for reporting US exam results for suspected pediatric appendicitis was successfully adopted by a pediatric radiology department at a large tertiary children's hospital and stratifies risk for children based on their likelihood of appendicitis.

Body mass index, pain score and Alvarado score are useful predictors of appendix visualization at ultrasound in adults

The study objective was to find factors predictive of ultrasound visualization of the appendix in patients with suspected appendicitis. A total of 238 consecutive adult patients (178 women, mean age 38.9 y, weight 58.2 kg, body mass index 22.7) who underwent appendiceal ultrasound from January to December 2011 were included. Appendicitis was confirmed in 171 patients (171/238, 71.9%). Ultrasound sensitivity, specificity and accuracy were 64%, 90% and 71%, respectively. The appendix was visualized at ultrasound in 126 patients (group 1) and not visualized in 112 patients (group 2). Group 1 had a lower body mass index, higher pain score and higher Alvarado score. The chances of visualizing the appendix in patients with body mass indexes ≤22, pain scores ≥6, and Alvarado scores ≥6 were 2.3, 2.9, and 3.8 times higher than those of their counterparts, respectively. Therefore, in patients with these factors, the use of ultrasound may be beneficial in the diagnosis of acute appendicitis.

The predictive value of Alvarado score, inflammatory parameters and ultrasound imaging in the diagnosis of acute appendicitis

OBJECTIVE

Acute appendicitis (AA) is one of the most common surgical emergencies. Despite extraordinary advances in modern investigations, the accurate diagnosis of AA remains an enigmatic challenge. The aim of this study was to compare and evaluate the diagnostic accuracy of inflammatory parameters [C-reactive protein (CRP), procalcitonin (PCT), erythrocyte sedimentation rate (ESR)], ultrasound (US) and Alvarado score (AS) in reducing the rate of negative appendectomies.

MATERIAL AND METHODS

Two hundred seventy-eight patients were included in this study. Patients were separated into two main groups as the surgery group (n=184) and non-operative group (n=94). Complete blood count, ESR and PCT levels were assessed, abdominal US was performed and AS was calculated for all patients.

RESULTS

In the surgery group, clinical predictive factors for histopathologic results such as AS ≥7, AA signs on US, neutrophilia and leukocytosis were significant. Neutrophilia and leukocytosis had the highest accuracy rate among these factors. Inflammatory parameters were not predictive for histopathologic results, although higher CRP and PCT levels were significant in perforated and necrotizing appendicitis. Multifactorial regression analyses showed that AS was not of significant predictive value in the non-operative group.

CONCLUSION

There was no superiority of AS and/or US in the diagnosis of AA. Recent findings have shown the most reliable parameters in the diagnosis of AA to be primarily 'neutrophilia' and secondarily 'leukocytosis'. Other results of this study indicated that inflammatory parameters (CRP, PCT, ESR) were not superior to other parameters but CRP and PCT levels were significantly high in complicated cases.

Perforated appendix with abscess: Immediate or interval appendectomy? Some examples to explain our choice

•

There are no clear guidelines in the treatment of a perforated appendicitis associated with localized abscess.

•

Our team’s therapeutic choice, also with presence of coprolith, is the initial conservative case management followed by a routine interval appendectomy.

•

Interval appendectomy should be performed not later than 4 months after discharge.

Introduction

There are no clear guidelines in the treatment of a perforated appendicitis associated with periappendiceal abscess without generalized peritonitis.

Presentation of cases

We retrospectively studied six examples of treated children in order to discuss the reasons of our team’s therapeutic approach. Some children were treated with a conservative antibiotic therapy to solve acute abdomen pain, planning a routine interval appendectomy after some months. Others, instead, underwent an immediate appendectomy.

Discussion

By examining these examples we wanted to highlight how the first approach may be associated with shorter surgery time, fewer overall hospital days, faster refeeding and minor complications.

Conclusion

Our team’s therapeutic choice, in the case of a perforated appendicitis with an abscess and coprolith is an initial conservative case management followed by a routine interval appendectomy performed not later than 4 months after discharge.

Journal Club: the Alvarado score as a method for reducing the number of CT studies when appendiceal ultrasound fails to visualize the appendix in adults

OBJECTIVE. The purpose of this article is to evaluate the hypothesis that Alvarado scores of 3 or lower identify adult patients who are unlikely to benefit from CT after appendiceal ultrasound fails to show the appendix and is otherwise normal. MATERIALS AND METHODS. We identified 119 consecutive adults for whom the appendix was not seen on otherwise normal appendiceal sonography performed as the first imaging study for suspected appendicitis, who subsequently underwent CT within 48 hours, and whose data permitted retrospective calculation of admission Alvarado scores. Specific benefits of CT were defined as diagnoses of appendicitis or significant alternative findings, and specific benefits were compared between patients with Alvarado scores of 3 or less and 4 or higher. Significant alternative findings on CT were findings other than appendicitis that were treated with medical or surgical therapy during the admission or that were to be addressed during follow-up care. Diagnostic reference standards were discharge diagnoses, pathologic examinations, and clinical follow-up. RESULTS. No patients (0.0%, 0/49) with Alvarado scores 3 or lower had appendicitis, compared with 17.1% (12/70) of patients with Alvarado scores 4 or higher (p = 0.001), and CT showed neither appendicitis nor significant alternative findings in 85.7% (42/49) versus 58.6% (41/70) of these patients, respectively (p = 0.002). The rates of perforated appendicitis, as well as significant alternative CT findings, did not differ significantly. CONCLUSION. Adults with Alvarado scores 3 or lower who have nonvisualized appendixes and otherwise normal appendiceal sonography are at very low risk for appendicitis or significant alternative findings and therefore are not likely to benefit from CT.

Properties of serial ultrasound clinical diagnostic pathway in suspected appendicitis and related computed tomography use

OBJECTIVES

The primary objective was to determine the diagnostic accuracy of a serial ultrasound (US) clinical diagnostic pathway to detect appendicitis in children presenting to the emergency department (ED). The secondary objective was to examine the diagnostic performance of the initial and interval US and to compare the accuracy of the pathway to that of the initial US.

METHODS

This was a prospective cohort study of 294 previously healthy children 4 to 17 years old with suspected appendicitis and baseline pediatric appendicitis scores of ≥2, who were managed with the serial US clinical diagnostic pathway. This pathway consisted of an initial US followed by a clinical reassessment in each patient and an interval US and surgical consultation in patients with equivocal initial US and persistent concern about appendicitis. The USs were interpreted by published criteria as positive, negative, or equivocal for appendicitis. Children in whom this pathway did not rule in or rule out appendicitis underwent computed tomography (CT). Cases with missed appendicitis, negative operations, and CTs after the pathway were considered inaccurate. The primary outcome was the diagnostic accuracy of the serial US clinical diagnostic pathway. The secondary outcomes included the test performance of the initial and interval US imaging studies.

RESULTS

Of the 294 study children, 111 (38%) had appendicitis. Using the serial US clinical diagnostic pathway, 274 of 294 children (93%, 95% confidence interval [CI] = 90% to 96%) had diagnostically accurate results: 108 of the 111 (97%) appendicitis cases were successfully identified by the pathway without CT scans (two missed and one CT), and 166 of the 183 (91%) negative cases were ruled out without CT scans (14 negative operations and three CTs). The sensitivity of this pathway was 108 of 111 (97%, 95% CI = 94% to 100%), specificity 166 of 183 (91%, 95% CI = 87% to 95%), positive predictive value 108 of 125 (86%; 95% CI = 79% to 92%), and negative predictive value 166 of 169 (98%, 95% CI = 96% to 100%). The diagnostic accuracy of the pathway was higher than that of the initial US alone (274 of 294 vs. 160 of 294; p < 0.0001). Of 123 patients with equivocal initial US, concern about appendicitis subsided on clinical reassessment in 73 (no surgery and no missed appendicitis). Of 50 children with persistent symptoms, 40 underwent interval US and 10 had surgical consultation alone. The interval US confirmed or ruled out appendicitis in 22 of 40 children (55.0%) with equivocal initial US, with one false-positive interval US.

CONCLUSIONS

The serial US clinical diagnostic pathway in suspected appendicitis has an acceptable diagnostic accuracy that is significantly higher than that of the initial US and results in few CT scans. This approach appears most useful in children with equivocal initial US, in whom the majority of negative cases were identified at clinical reassessment and appendicitis was diagnosed by interval US or surgical consultation in most study patients.

Accuracy of bedside emergency physician performed ultrasound in diagnosing different causes of acute abdominal pain: a prospective study

OBJECTIVE

Abdominal pain is a common complaint in the emergency department and accurate diagnosis of its etiology may affect the patient's outcome.

METHOD

Patients with abdominal pain underwent ultrasound study first by trained emergency physicians and then by radiologists blinded to emergency physician's results.

RESULT

Emergency physician who performed bedside ultrasound had 78% diagnostic accuracy. Emergency physicians showed better results in diagnosing some entities (abdominal aortic aneurysm and renal stones) than the others (acute appendicitis, cholelithiasis, and cholecystitis).

CONCLUSION

Bedside ultrasound can accurately identify the etiology of acute nontraumatic abdominal pain in the hands of emergency physicians.

Value of short-interval computed tomography when sonography fails to visualize the appendix and shows otherwise normal findings

OBJECTIVES

The purpose of this study was to evaluate the type and incidence of disorders revealed by short-interval computed tomography (CT) in patients with suspected appendicitis after graded compression sonography fails to reveal the appendix and shows otherwise normal findings.

METHODS

Computed tomographic findings and clinical courses were assessed retrospectively for 318 patients identified consecutively in a searchable database who met inclusion criteria specifying that sonography was the initial imaging examination for suspected appendicitis; sonography revealed nonvisualization of the appendix and otherwise normal results; and abdominopelvic CT was performed within 48 hours after sonography.

RESULTS

Of the 318 patients, short-interval CT revealed normal findings in 250 (78.6%). Appendicitis was revealed in 52 (16.4%) others, of whom 7 had perforation and all of whom had pathologic results confirming these CT findings. Important alternative diagnoses other than appendicitis were revealed in 16 (5.0%) others, including 2 (0.6%) who required urgent surgery and 14 (4.4%) who did not. No significant differences were observed between adult patients (>18 years) and pediatric patients.

CONCLUSIONS

Most short-interval CT scans in this clinical setting reveal normal findings, and relatively few disclose appendicitis or disorders that require urgent surgery. In view of concerns regarding radiation exposure associated with CT, these observations argue for the development of clinical triage methods that differentiate patients who are likely to benefit from short-interval postsonography CT from those who are not.

False-negative appendicitis at ultrasound: nature and association

The objective was to describe nature and factors associated with false-negative ultrasound (US) for adult appendicitis. Patients with pathologically proven appendicitis and pre-operative US from January 2011 to May 2013 were included in this retrospective case-control study. They were divided into true-positive and false-negative groups, matched by age and gender. There were 112 patients (40 men, mean age = 40 y, 56 true positives) included. Two factors were found differ significantly: abdominal wall thickness and pain score. Greater abdominal wall thickness (18.6 mm vs. 14.9 mm, p = 0.001) and lower pain score (6.6 vs. 7.5, p = 0.018) were statistically associated with false negativity. The two groups did not differ significantly in terms of weight, height, body mass index, symptom duration, Alvarado score, US examination time, appendix position/size, perforation rate and operator. In conclusion, lower pain score and increased abdominal wall thickness are associated with false negativity in US examinations.

Utility of CT after sonography for suspected appendicitis in children: integration of a clinical scoring system with a staged imaging protocol

To improve diagnosis of pediatric appendicitis, many institutions have implemented a staged imaging protocol utilizing ultrasonography (US) first and then computed tomography (CT). A substantial number of children with suspected appendicitis undergo CT after US, and the efficient and accurate diagnosis of pediatric appendicitis continues to be challenging. The objective of the study is to characterize the utility of CT following US for diagnosis of pediatric appendicitis, in conjunction with a clinical appendicitis score (AS). Imaging studies of children with suspected appendicitis who underwent CT after US in an imaging protocol were retrospectively reviewed by three radiologists in consensus. Chart review derived the AS (range 0-10) and obtained the patient diagnosis and disposition, and an AS was applied to each patient. Clinical and radiologic data were analyzed to assess the yield of CT after US. Studies of 211 children (mean age 11.3 years) were included. The positive threshold for AS was determined to be 6 out of 10. When AS and US were concordant (N = 140), the sensitivity and specificity of US were similar to CT. When AS and US were discordant (N = 71) and also when AS ≥ 6 (N = 84), subsequent CT showed superior sensitivity and specificity to US alone. In the subset where US showed neither the appendix nor inflammatory change in the right lower quadrant (126/211, 60 % of scans), when AS < 6 (N = 83), the negative predictive value (NPV) of US was 0.98. However, when AS ≥ 6 (N = 43), NPV of US was 0.58, and the positive predictive value of subsequent CT was 1. There was a significant decrease in depiction of the appendix on US with patient weight-to-age ratio of >6 (kg/year, P < 0.001) and after-hours (1700 -0730 hours) performance of US (P < 0.001). Results suggest that the appendicitis score has utility in guiding an imaging protocol and support the contention that non-visualization of the appendix on US is not intrinsically non-diagnostic. There was little benefit to additional CT when AS < 6 and US did not show the appendix or evidence of inflammation; this would have avoided CT in 140/211 (66 %) patients. CT demonstrated benefit when AS ≥ 6, suggesting that cases with AS ≥ 6 and features that limit depiction of the appendix on US may be triaged to CT.

Evaluation of acute appendicitis by pediatric emergency physician sonography

STUDY OBJECTIVE

We investigate the accuracy of pediatric emergency physician sonography for acute appendicitis in children.

METHODS

We prospectively enrolled children requiring surgical or radiology consultation for suspected acute appendicitis at an urban pediatric emergency department. Pediatric emergency physicians performed focused right lower-quadrant sonography after didactics and hands-on training with a structured scanning algorithm, including the graded-compression technique. We compared their sonographic interpretations with clinical and radiologic findings, as well as clinical outcomes as defined by follow-up or pathologic findings.

RESULTS

Thirteen pediatric emergency medicine sonographers performed 264 ultrasonographic studies, including 85 (32%) in children with pathology-verified appendicitis. Bedside sonography had a sensitivity of 85% (95% confidence interval [CI] 75% to 95%), specificity of 93% (95% CI 85% to 100%), positive likelihood ratio of 11.7 (95% CI 6.9 to 20), and negative likelihood ratio of 0.17 (95% CI 0.1 to 0.28).

CONCLUSION

With focused ultrasonographic training, pediatric emergency physicians can diagnose acute appendicitis with substantial accuracy.

Contemporary management of abdominal surgical emergencies in infants and children

BACKGROUND

Acute abdominal complaints in children are common presentations in the emergency department. The aetiology, presentation, diagnosis and management often differ from those in adults.

METHODS

This review was based on expert paediatric surgical experience confirmed by evidence from the literature obtained by searching PubMed and the Cochrane Library. Keywords used were the combinations of 'abdominal emergencies', 'acute abdomen' and the disorders 'acute appendicitis', 'intussusception', 'volvulus', 'Meckel's diverticulum', 'incarcerated inguinal hernia', 'testicular torsion' and 'ovarian torsion' with 'children'. Information was included from reviews, randomized clinical trials, meta-analyses, and prospective and retrospective cohort studies.

RESULTS

Presentation and symptoms of abdominal emergencies, especially in young children, vary widely, which renders recognition of the underlying disorder and treatment challenging. Critically targeted imaging techniques are becoming increasingly important in obtaining the correct diagnosis without unnecessary delay. Minimally invasive techniques have become the method of choice for the diagnosis and treatment of many abdominal emergencies in children.

CONCLUSION

Knowledge of abdominal disorders in childhood, their specific presentation, diagnosis and treatment facilitates management of children with acute abdomen in emergency departments. Imaging and minimally invasive techniques are becoming increasingly important in the diagnosis of acute abdomen in children. Urgent operation remains the cornerstone of therapy for most acute abdominal disorders.

On the Role of Ultrasonography and CT Scan in the Diagnosis of Acute Appendicitis

The purposes of this study were to revisit the utility of ultrasonography (USG) as a primary imaging modality in acute appendicitis (AA) and to establish the role of CT scan as a second-line/problem-solving modality. All cases of suspected AA were referred for urgent USG. USG was done with standard protocol for appendicitis. Limited computed tomographic (CT) scan [NCCT ± CECT (IV contrast only)] was done for the lower abdomen and pelvis where sonographic findings were equivocal. One hundred and twenty-one patients were referred for USG for suspected appendicitis. Eight-four patients underwent surgery for AA based on clinical as well as imaging findings, of whom 76 had appendicitis confirmed at histopathology. Three patients were misdiagnosed (3.6 %) on USG as appendicitis. Of 76 patients of appendicitis confirmed histopathologically, 63 (82.8 %) had features of appendicitis on USG and did not require any additional imaging modality. Of 121 patients, 12 (10 %) needed CT scan because of atypical features on USG. Of these 12 patients, seven had retrocecal appendicitis, and three high-up paracolic appendicitis. USG alone had sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of 81, 88, 92.6, 71.6, and 83 %, respectively. When combined with CT scan in select cases, the sensitivity, specificity, PPV, NPV, and accuracy of combined USG + CT scan were 96 % (P = 0.0014), 89 %, 93 %, 93.5 % (P = 0.0001), and 93 % (P = 0.0484), respectively. Twenty-eight (23 %) patients were given alternative diagnosis on USG. Dedicated appendiceal USG should be used as a primary imaging modality in diagnosing or excluding AA. Appendiceal CT can serve as a problem-solving modality.

Sonography for appendicitis: nonvisualization of the appendix is an indication for active clinical observation rather than direct referral for computed tomography

PURPOSE

To determine the prevalence of perforated and nonperforated appendicitis in patients with nonvisualization of the appendix on ultrasound (US) performed for suspected appendicitis, and to evaluate the value of CT in these patients.

METHODS

We analyzed 400 consecutive patients undergoing US for suspected appendicitis. Of these patients, 260 had nonvisualization of the appendix, but otherwise normal scans. We analyzed the clinical outcome in these patients to determine the prevalence of appendicitis, referrals for CT, and the contribution of CT in these patients.

RESULTS

Of the 400 patients, 140 (35%) had either a normal (80 patients, 25%) or an abnormal appendix (60 patients, 15%); 260 (65%) had nonvisualization of the appendix. Overall 75 patients had appendicitis (18.8%) and 17 (4.3%) had appendicitis with perforation. Of the 260 patients with nonvisualization of the appendix, 14 patients (5.4%) had appendicitis and 2 were perforated (0.8%). The prevalence of perforated and nonperforated appendicitis in this group was significantly lower than the overall group (p < 0.001 and p < 0.01, respectively). Of these 260 patients, 101 patients (38.8%) had CT within 48 hours and 79 (78.2%) had normal scans.

CONCLUSIONS

Patients with nonvisualization of the appendix on US, but otherwise normal scans, are at significantly lower risk for appendicitis, either perforated or nonperforated. Active clinical observation should be considered in these patients, rather than direct referral for CT.