Ultrasonographic findings identifying the faecal-impacted appendix: differential findings with acute appendicitis

Evaluating the value of different sonographic findings in diagnosis of acute appendicitis in children

INTRODUCTION

Appendicitis is one of the most common paediatric surgical emergencies occurring in about 7% of healthy children. To make a definitive diagnosis preferably avoiding unnecessary X-ray radiation exposure, ultrasound is the ideal modality. The aim of this study is to evaluate the diagnostic value of sonographic findings in children with acute appendicitis and comparing them with surgical findings to demonstrate the safety, simplicity and accuracy of this procedure in emergency departments as the first diagnostic procedure.

MATERIALS AND METHODS

One hundred and eight children aged 1-15 years suspected of acute appendicitis in our tertiary hospital emergency department enrolled the study. Patients presenting as acute abdomen suspected as having acute appendicitis underwent abdominal ultrasonography (US) at first. Sonographic findings were compared to surgical and pathologic results, and sensitivity and specificity of each sonographic parameter in paediatric appendicitis were evaluated.

RESULTS

The analysis of sonographic results showed that 67.6% of patients had acute appendicitis, 13.9% had perforated appendicitis and 18.5% had normal appendix. On the other hand, there were acute appendicitis in 63.9% of patients, perforated appendicitis in 12% and normal appendix in 8.3% in surgical reports. Sensitivity of uncompressible appendicitis, appendicitis, maximal outer diameter (MOD) above 6 mm, maximal mural thickness (MMT) above 3 mm, round appendix was 98.68%, 28.04%, 94.74%, 61.84% and 68.42%, respectively. Specificity of incompressible appendicitis, appendicitis, MOD above 6 mm, MMT above 3 mm, round appendix was 64.71%, 96.15%, 64.71%, 82.35% and 94.12%, respectively. Overall sensitivity and specificity of US in appendicitis were 97.56% and 69.23%, respectively.

CONCLUSION

According to the findings of this study, sensitivity of US in diagnosing appendicitis is higher than other studies, but its specificity was lower. Ultrasonographic accuracy and efficacy to diagnose acute appendicitis in children are high enough to allow clinicians to do it as an imaging modality of first choice, and also, in problematic cases to assist correct clinical diagnosis avoiding unnecessary X-ray exposure, decreasing negative appendectomies, decreasing perforation rate and lowering the cost of patients. Furthermore, negative US do not justify immediate computed tomography because clinical re-evaluation and a second US can help greatly the clinicians in the correct diagnosis.

Value of Periappendiceal Fat Sign on Ultrasound in Acute Appendicitis

Introduction

Acute right lower quadrant abdominal pain is one of the most common surgical presentations to the emergency department with acute appendicitis being the topmost differential diagnosis. Although computed tomography (CT) is the gold standard in diagnosing appendicitis, in our setup ultrasound is often the initial imaging modality available in urgent care settings especially for children and pregnant females. On ultrasound, an inflamed appendix has a diameter of 6 mm or more and is non-compressible. Increased periappendiceal fat echogenicity is an important ancillary sign of acute appendicitis that supports the sonographic diagnosis of acute appendicitis. To determine the association of periappendiceal fat echo sign (PFES) on ultrasound in surgically proven cases of acute appendicitis.

Methods

This cross-sectional study was held at the Department of Radiology at the Aga Khan University Hospital in Karachi, Pakistan. Periappendiceal fat echogenicity was assessed and prospectively graded in 59 patients. These patients had sonographic features of acute appendicitis which was later confirmed by surgery. Data were collected on a proforma and later analyzed. Frequency of increased periappendiceal fat echogenicity in acute appendicitis was calculated. Association of PFES with gender and ascites was evaluated with Fischer's exact test and with patient's age and appendiceal diameter was assessed using analysis of variance (ANOVA).

Results

Increased periappendiceal fat echogenicity was seen in 89.8% of patients with acute appendicitis. 10.2% of patients had acute appendicitis with normal surrounding fat. Mean appendiceal diameter in patients with grade 3 PFES was significantly more than those with grade 2 or grade 1 PFES. PFES had no association with age and gender of the patient or with ascites.

Conclusion

Increased periappendiceal fat echogenicity is an important ancillary sign of acute appendicitis that helps support its sonographic diagnosis.

Sonographic differentiation of complicated from uncomplicated appendicitis

OBJECTIVE

This study aims to differentiate acute uncomplicated and complicated appendicitis, by investigating the correlation between sonographic findings and histological results in different types of paediatric appendicitis.

METHODS

This is a retrospective study of 1017 paediatric patients (age < 18 years) who underwent ultrasound by paediatric radiologists before appendicectomy at our institution between 2006 and 2016. Histologically, uncomplicated appendicitis was primarily associated with transmural infiltration of neutrophil granulocytes, while complicated appendicitis was characterised by transmural myonecrosis. Logistic regression analyses were used to investigate the association between sonographic and histological findings.

RESULTS

Out of 566 (56%) male and 451 (44%) female patients with a mean age of 10.7 years, uncomplicated appendicitis was histologically diagnosed in 446 (44%) children and complicated appendicitis was diagnosed in 348 (34%) cases. The following ultrasound findings were significantly associated with complicated appendicitis in multivariate regression: an increased appendiceal diameter (OR = 1.3, p < .001), periappendiceal fat inflammation (OR = 1.5, p = 0.02), the presence of an appendicolith (OR = 1.7, p = 0.01) and a suspected perforation (OR = 6.0, p < .001) by the pediatric radiologist. For complicated appendicitis, an appendiceal diameter of more than 6 mm had the highest sensitivity (98%), while a sonographically suspected perforation showed the highest specificity (94%).

CONCLUSION

Abdominal sonography by paediatric radiologists can differentiate between uncomplicated and complicated appendicitis in paediatric patients by using an increased appendiceal diameter, periappendiceal fat inflammation, the presence of an appendicolith and a suspected perforation as discriminatory markers.

ADVANCES IN KNOWLEDGE

This paper demonstrates expanded information on ultrasound, which is not only an essential tool for diagnosing appendicitis, but also a key method for distinguishing between different forms of appendicitis when performed by paediatric radiologists. Compared with previous studies, the crucial distinction features in our analysis are 1) the definition of gangrene and not primarily perforation as an acute complicated appendicitis enabling early decision-making by sonography and 2) a large number of patients in a particularly affected age group.

The Use of Clinician-Performed Ultrasonography to Determine the Treatment Method for Suspected Paediatric Appendicitis

Objective

To investigate whether the clinician-performed ultrasonography based on the specific criteria for paediatric appendicitis could decrease the negative appendectomy rate without treatment failure.

Methods

The study was a retrospective review of paediatric patients with suspected appendicitis who presented at the emergency department of a teaching hospital over a period of 18 months. The clinicians performed the ultrasound and decided whether the patients with suspected appendicitis should be referred to surgery or managed conservatively. The determinative ultrasound criteria were the presence of periappendiceal fat infiltration and/or an obstructing appendicolith.

Results

The 166 paediatric patients with suspected appendicitis underwent ultrasonography performed by clinicians on weekdays; forty (24.1%) cases with an obstructing appendicolith and/or periappendiceal fat infiltration were treated surgically, and none had a pathologically negative appendectomy, which was significantly lower than the number in the computed tomography scan group (10.4%, 11/106) on weeknights or weekends. The remaining 126 (75.8%) patients without obstructing appendicolith or periappendiceal fat infiltration were treated conservatively, regardless of their appendiceal diameter, and no patients experienced a treatment failure.

Conclusions

The clinician-performed ultrasonography bases on the strict use of above specific ultrasound criteria to determine treatment strategies for suspected paediatric appendicitis can reduce the negative appendectomies without treatment failure. (Hong Kong j.emerg.med. 2015;22:31-40)

Sonography of the normal appendix: its varied appearance and techniques to improve its visualization

The sonographic identification of the normal appendix is crucial to the success of ultrasound as an effective screening method for diagnosing acute appendicitis. The normal appendix can be challenging to identify on sonography, however, because it is a narrow tubular structure and has variable sonographic appearances. Moreover, the tip of the appendix can be quite variable in location. In this article, we review the various sonographic appearances of the normal appendix and highlight strategies to improve its visualization.

Appendix not seen: the predictive value of secondary inflammatory sonographic signs

BACKGROUND

Acute appendicitis is the most prevalent emergency surgical diagnosis in children. Although traditionally a clinical diagnosis, the diagnosis of acute appendicitis is uncertain in approximately 30% of pediatric patients. In attempts to avoid a misdiagnosis and facilitate earlier definitive care, imaging modalities such as ultrasonography have become important tools. In many pediatric studies, the absence of a visualized appendix with no secondary sonographic features has been reported as a negative study result, and a study where the appendix is not seen but demonstrates secondary features is often deemed equivocal. With ultrasound appendiceal detection rates reported at 60% to 89%, the dilemma of the nonvisualized appendix or equivocal study is frequently faced by clinicians.

OBJECTIVE

This study aimed to assess the value of the nonvisualized appendix on ultrasound and the association of secondary sonographic findings in pediatric patients with acute right lower quadrant pain undergoing ultrasound, in whom acute appendicitis was a diagnostic consideration.

METHODS

Retrospective case review of 662 consecutive children (age < 18 years) presenting to a pediatric emergency department with clinically suspected appendicitis, who had graded compression sonographic studies during the 24-month study period, was performed.

RESULTS

The appendix could not be visualized in 241 studies (37.7%). An alternate diagnosis was identified via sonography in 47 patients (19.5%). Twenty-five patients (12.9%) were taken for surgery where 17 (8.8%) had acute appendicitis confirmed via pathology. The specificity of moderate-to-large amounts of free fluid is 98%, phlegmon at 100%, pericecal inflammatory fat changes at 98%, and any free fluids with prominent lymph nodes at 81%. The odds ratio of appendicitis increases from 0.56 to 0.64 to 2.3 and 17.5, respectively, when there were 2 and 3 ultrasonographic inflammatory markers identified.

CONCLUSIONS

Although uncommonly seen, large amounts of free fluid, phlegmon, and pericecal inflammatory fat changes were very specific signs of acute appendicitis. In the absence of a distinctly visualized appendix, the presence of multiple secondary inflammatory changes provides increasing support of a diagnosis of acute appendicitis.

Transabdominal ultrasound for bowel evaluation

This article considers the case for a strategic place for ultrasound (US) bowel evaluation focusing on three common clinical contexts. These include imaging for suspected acute appendicitis and acute diverticulitis, as well as the role of US in a multimodality approach for the diagnosis and management of inflammatory bowel disease and associated complications.

Beyond acute appendicitis: imaging of additional pathologies of the pediatric appendix

Primary acute appendicitis is by far the most common pathological condition affecting the appendix. There are differential diagnoses, however, when an abnormal appendix is found by imaging. The purpose of this paper is to highlight the imaging and clinical manifestations of less common appendiceal abnormalities in children. Familiarity with these alternative diagnoses might be particularly helpful in guiding management of the child whose clinical presentation is not typical for primary acute appendicitis.

Reevaluating the sonographic criteria for acute appendicitis in children: a review of the literature and a retrospective analysis of 246 cases

RATIONALE AND OBJECTIVES

There has been little rigorous evaluation of the sonographic criteria for acute appendicitis in children. Our clinical experience has called the traditional diagnostic criteria into question. We set out to review the literature, evaluate the most commonly applied diagnostic criteria for acute appendicitis, and identify those criteria that best predict the presence of disease.

MATERIALS AND METHODS

A critical review of the literature concerning the sonographic diagnosis of acute appendicitis was performed. Based on diagnostic criteria identified in that review, two independent, blinded pediatric radiologists retrospectively reviewed 246 right lower quadrant ultrasound examinations in which the appendix was identified with attention to commonly described diagnostic criteria for acute appendicitis. Multivariate and classification and regression tree analysis were performed to identify criteria that predict appendicitis.

RESULTS

In a multivariate analysis, inflammation of the periappendiceal fat is the only finding that statistically significantly predicts acute appendicitis (OR = 68.93, P < .0001). Other criteria such as diameter, noncompressibility, hyperemia, the presence of an appendicolith, and loss of stratification of the appendiceal wall do not independently predict appendicitis.

CONCLUSION

Periappendiceal fat infiltration is the most important diagnostic criterion for acute appendicitis in children. Strict application of other criteria such as diameter should be avoided.

Perforated appendicitis and appendicolith in a child presenting as intussusception: a case report

Simultaneous diagnoses of intussusception and appendicitis in the same patient have rarely been described in the pediatric literature. A case of a 30-month-old boy is presented with an initial diagnosis of intussusception that was successfully reduced by air contrast enema. When the patient's condition deteriorated, a diagnostic search surprisingly revealed a missed perforated appendicitis with an appendicolith that had been part of the intussusception. The patient's hospitalization and surgical course is described along with a discussion of the intermingling of intussusception and appendicitis in a young child. This case illustrates the need to consider alternative diagnoses when a patient's course takes an unexpected and confusing turn.

Ultrasonography of normal and abnormal appendix in children

Appendicitis is the most common acute surgical emergency of childhood. Since the original report by Puylaert in 1986, the use of ultrasonography in the diagnosis of appendicitis has been the subject of considerable study. Among the reported diagnostic criteria, the maximal outer diameter (MOD) of the appendix is accepted as the one of the most reliable criteria used to differentiate between a normal appendix and acute appendicitis. However, MOD measurement is subject to inaccuracies because luminal distention by non-compressible, non-inflammatory material such as fecal material, or increased maximal mural thickness due to reactive mucosal lymphoid hyperplasia, or a medical cause due to a generalized gastrointestinal disease, such as Crohn’s disease, can cause the measurement to exceed the upper limits of normality. The aim of this article is to introduce the spectrum of ultrasonographic findings in the normal and abnormal appendix and eventually to reduce unnecessary surgery in children.

Typical signs of acute appendicitis in ultrasonography mimicked by other diseases?

BACKGROUND

The diagnosis of acute appendicitis in pediatric patients is difficult. There are patients with positive ultrasonography without clinical or histological confirmation of acute appendicitis. It is essential to recognise these patients to avoid unnecessary surgery.

METHODS

During 1 year, we compared the patients with 'false-positive' ultrasonography with those with 'true-positive' and those with 'true-negative' ultrasonography.

RESULTS

Eighty-two patients were admitted to our inpatient ward for suspected appendicitis. Ultrasonography was performed on 68 patients. In sixteen cases, the ultrasonography showed typical signs of acute appendicitis though the patients turned out to be negative for acute appendicitis either by an observation period (n = 13) or by negative histology (n = 3). We could not find any significant differences between the groups in terms of age, gender or laboratory inflammation markers, though the latter tended to be elevated in patients with confirmed appendicitis.

CONCLUSIONS

There are patients with clearly visible typical signs of acute appendicitis that do not need surgery and cannot be distinguished from others by age, gender or laboratory values. In conclusion, the clinical presentation still is the determining indicator for need of surgery. The underlying cause of the visible changes of the appendiceal area remains unclear, but there are several presumptions.

Diagnostic value of maximal-outer-diameter and maximal-mural-thickness in use of ultrasound for acute appendicitis in children

AIM: To evaluate the maximal-outer-diameter (MOD) and the maximal-mural-thickness (MMT) of the appendix in children with acute appendicitis and to determine their optimal cut-off values to diagnose acute appendicitis.

METHODS: In total, 164 appendixes from 160 children between 1 and 17 years old (84 males, 76 females; mean age, 7.38 years) were examined by high-resolution abdominal ultrasound for acute abdominal pain and the suspicion of acute appendicitis. We measured the MOD and the MMT at the thickest point of the appendix. Patients were categorized into two groups according to their medical records: patients who had surgery (surgical appendix group) and patients who did not have surgery (non-surgical appendix group). Data were analyzed by MedCalc v.9.3. The rank sum test (Mann-Whitney test) was used to evaluate the difference in the MOD and the MMT between the two groups. ROC curve analysis was used to determine the optimal cut-off value of the MOD and the MMT on diagnosis of acute appendicitis.

RESULTS: There were 121 appendixes (73.8%) in the non-surgical appendix group and 43 appendixes (26.2%) in the surgical appendix group. The median MOD differed significantly between the two groups (0.37 cm vs 0.76 cm, P < 0.0001), and the median MMT also differed (0.15 cm vs 0.33 cm, P < 0.0001). The optimal cut-off value of the MOD and the MMT for diagnosis of acute appendicitis in children was > 0.57 cm (sensitivity 95.4%, specificity 93.4%) and > 0.22 cm (sensitivity 90.7%, specificity 79.3%), respectively.

CONCLUSION: The MOD and the MMT are reliable criteria to diagnose acute appendicitis in children. An MOD > 0.57 cm and an MMT > 0.22 cm are the optimal criteria.

[Diseases of the peritoneum and mesenterium]

Peritoneal diseases can be seen in the different imaging modalities either as fluid collections or solid tumors along the ligaments, mesenteries, and spaces of the peritoneal cavity. The broad spectrum of different abnormalities includes inflammatory, infectious, traumatic, and neoplastic diseases. In this article, a large variety of peritoneal abnormalities such as ascites, peritonitis, intraperitoneal hemorrhage, and both primary and secondary peritoneal tumors are discussed. The different imaging modalities, characteristic radiological features, and typical pathways of anatomic spread are explained.