Sonographic appearance of the normal appendix in adults

Comparison of ultrasound assisted and intraoperative diameter measurement in acute appendicitis

Detailed anamnesis and systematic physical examination are often relevant in the diagnostic routine of acute appendicitis. However, physicians are increasingly motivated to obtain radiological approval. Inherent limitations due to radiologists' experience and the presenting anatomy may result in contradictory outcomes between the described and intraoperative findings. In this study, a comparison of anthropometric measurements of the appendix vermiformis obtained by radiologists and surgeons in children with acute appendicitis is discussed. The external appendiceal diameter in 53 patients who underwent surgery between April 2022 and January 2024 was measured at three different anatomical locations during preoperative ultrasound and intraoperatively with the help of Vernier calipers. Appendectomy materials were classified into negative, acute, and complicated appendicitis subgroups on the basis of histopathological results. The widest median diameter, expressed in millimeters, was analyzed statistically in terms of diagnostic accuracy. Histopathological analysis revealed negative appendectomy in 15.1%, acute appendicitis in 66%, and complicated appendicitis in 18.8% of the patients. The median age at presentation was 11.4 years (4-17.3 years), and 45.3% of the patients were females. The average median appendiceal diameter was 7.8 ± 2.4 mm according to the caliper and 7.9 ± 2.7 mm according to ultrasound (p > 0.05). The evaluation by the caliper revealed a much smaller diameter in 19 patients than did ultrasound. The appendiceal diameter of eight documented negative appendectomy samples was 7 mm or greater. US failed to identify the presence of an appendicolith in 11 cases (20.8%), all of which were disclosed during histopathological evaluation. It is possible to conclude that ultrasound and intraoperative anthropometric measurements correlate according to our study. Diagnostic accuracy, however, which is individually based on ultrasound appendix diameter values greater than 6 mm, is controversial. It is clear that comparison and further reinterpretation of such anthropometric measurements in light of histopathological consequences may help diminish the frequency of negative and perforated appendectomies.

Colonic Diverticulitis Location Affects the Diagnostic Accuracy of Point-of-Care Ultrasound: A Multicenter, 10-Year Study

OBJECTIVE

Point-of-care ultrasound (PoCUS) has high sensitivity and specificity in diagnosing uncomplicated colonic diverticulitis in Western patients. Evidence regarding the accuracy of PoCUS in Asian patients in which diverticulitis frequently occurs in the right-side colon is lacking. This multicenter, 10-y study was aimed at evaluating the diagnostic accuracy of PoCUS in various locations of uncomplicated diverticulitis among Asians.

METHODS

A convenience sample of patients with suspected colonic diverticulitis who had undergone computed tomography (CT) were eligible. Patients undergoing PoCUS before CT were included. The primary outcome was the diagnostic accuracy of PoCUS in the various locations, compared with the final diagnosis made by the expert physicians. The sensitivity, specificity, positive predictive value and negative predictive value were computed. The logistic regression model was used to investigate the possible factors related to the accuracy of PoCUS.

RESULTS

A total of 326 patients were included. The overall accuracy of PoCUS was 92% (95% confidence interval [CI]: 89.1%-95.0%) and was lower in the cecum (84.3%, 95% CI: 77.8%-90.8%), compared with other locations (p < 0.0001). Nine of 10 false positives had the final diagnosis of appendicitis: 5 had an outpouching structure whose origin in the cecum could not be traced and 4 had elongated "diverticula." Moreover, body mass index was negatively associated with the accuracy of PoCUS in cecal diverticulitis (odds ratio: 0.79, 95% CI: 0.64-0.97) after adjusting for other covariates.

CONCLUSION

Point-of-care ultrasound exhibits high diagnostic accuracy in diagnosing uncomplicated diverticulitis in the Asian population. However, the accuracy varies according to location, and was relatively low in the cecum.

Gastrointestinal Ultrasound in Emergency Setting

Acute bowel diseases are responsible for more than one third of subjects who were referred to the emergency department for acute abdominal pain and gastrointestinal evaluation. Gastrointestinal ultrasound (GIUS) is often employed as the first imaging method, with a good diagnostic accuracy in the setting of acute abdomen, and it can be an optimal diagnostic strategy in young females due to the radiation exposure related to X-ray and computed tomography methods. The physician can examine the gastrointestinal system in the area with the greatest tenderness by ultrasound, thus obtaining more information and data on the pathology than the standard physical examination. In this comprehensive review, we have reported the most relevant indications and advantages to using ultrasound in the investigation of abdominal acute pain.

Intestinal ultrasound detects an increased diameter and submucosal layer thickness in the appendix of patients with ulcerative colitis compared to healthy controls - a prospective cohort study

BACKGROUND

Increasing evidence suggests that appendicectomy as alternative treatment for ulcerative colitis (UC), especially in patients with histopathological appendiceal inflammation. Intestinal ultrasound (IUS) is a non-invasive diagnostic modality to characterise appendiceal inflammation.

AIMS

To assess appendiceal IUS characteristics in UC patients and compare findings to healthy controls (HC).

METHODS

In this prospective study, appendiceal IUS was performed in consecutive UC patients with active (A; n = 35) or quiescent (Q; n = 30) disease and in HC (n = 30). Transverse appendiceal diameter (TAD) and additional IUS parameters (bowel wall thickness, submucosal layer thickness and colour Doppler signal) were assessed.

RESULTS

The appendix was visualised in 41/65 UC patients (63.1%; A vs. Q: 23/35 vs. 18/30, p = 0.67) and 18/30 (60%) HC. UC patients had a higher TAD (A: 5.5 mm, Q: 5.0 mm, HC: 4.3 mm; A-HC p < 0.01; Q-HC p = 0.01, A-Q p = ns) and submucosal layer thickness (A: 1.0 mm, Q: 1.0 mm, HC: 0.7 mm; A-HC p < 0.01, Q-HC: p = 0.01, A-Q: p = ns) when compared to HC. A TAD ≥6 mm corresponding to an ultrasonographic suspicion of acute appendicitis was mainly reported in A-UC patients (A: 43%; Q: 6%; HC: 0%, p = 0.01) and occurred irrespective of disease extent. However, none of the patients had a clinical suspicion of acute appendicitis.

CONCLUSION

A TAD ≥6 mm was predominantly seen in A-UC. TAD was higher in UC patients compared to HC irrespective of disease activity and was characterised by an increased submucosal layer thickness. IUS therefore has the potential to identify UC patients with appendiceal inflammation.

A novel Appendicitis TriMOdal prediction Score (ATMOS) for acute appendicitis in pregnancy: a retrospective observational study

Several scoring systems exist for the management of acute appendicitis (AA) during pregnancy. However, the systems are based on the nonpregnant adult population. The aim of this study was to create a highly accurate scoring system that can be applied to pregnant women and to compare it to the most commonly used scores in general population and pregnant women. The creation and subsequent implementation of a highly accurate score system could shorten the diagnostic period and minimize the use of (ionizing) diagnostic imaging allowing the selection of the best treatment approach in pregnant patients with acute appendicitis. A single-center, retrospective cohort observational study was conducted at the University Hospital Centre Zagreb, Zagreb, Croatia. Data were extracted from medical records of pregnant patients with suspected AA from January 2010 to December 2020. A total of 59 pregnant patients diagnosed with AA during pregnancy were identified, 41 were treated surgically, and 18 had non-surgical management. The main objective of our study was the detection of predictive factors of AA during pregnancy. Anorexia, pain migration to the right lower quadrant, rebound pain, axillary temperature over 37.3 °C, CRP/platelet ratio > 0.0422, neutrophil/lymphocyte ratio > 7.182, and ultrasonic signs of AA were scored. Scoring in Appendicitis TriMOdal Score (ATMOS) consists of positive clinical parameter, each bringing 1 point and other parameters mentioned above that bring 2 points each. The score ranges from 0 to 10. Our model of ATMOS yields a high area under the receiver-operating characteristic curve of 0.963. The positive likelihood ratio is 9.97 (95% CI 2.64-38.00), and the negative likelihood ratio is 0.1 (95% CI 0.03-0.31), meaning that 94% of cases with ATMOS > 4 have AA, while less than 13% with an ATMOS ≤ 4 have the diagnosis of AA. The potential of ATMOS differentiating AA during pregnancy was demonstrated. Future prospective, randomized trials are needed to evaluate its accuracy and whether it should be used instead of Alvarado or Tzanakis scores in clinical decision-making.Trial registration number ClinicalTrials.gov-NCT05202483. Date of registration: January 21, 2022.

Diagnosis and Management of Acute Appendicitis in Adults: A Review

IMPORTANCE

Acute appendicitis is the most common abdominal surgical emergency in the world, with an annual incidence of 96.5 to 100 cases per 100 000 adults.

OBSERVATIONS

The clinical diagnosis of acute appendicitis is based on history and physical, laboratory evaluation, and imaging. Classic symptoms of appendicitis include vague periumbilical pain, anorexia/nausea/intermittent vomiting, migration of pain to the right lower quadrant, and low-grade fever. The diagnosis of acute appendicitis is made in approximately 90% of patients presenting with these symptoms. Laparoscopic appendectomy remains the most common treatment. However, increasing evidence suggests that broad-spectrum antibiotics, such as piperacillin-tazobactam monotherapy or combination therapy with either cephalosporins or fluroquinolones with metronidazole, successfully treats uncomplicated acute appendicitis in approximately 70% of patients. Specific imaging findings on computed tomography (CT), such as appendiceal dilatation (appendiceal diameter ≥7 mm), or presence of appendicoliths, defined as the conglomeration of feces in the appendiceal lumen, identify patients for whom an antibiotics-first management strategy is more likely to fail. CT findings of appendicolith, mass effect, and a dilated appendix greater than 13 mm are associated with higher risk of treatment failure (≈40%) of an antibiotics-first approach. Therefore, surgical management should be recommended in patients with CT findings of appendicolith, mass effect, or a dilated appendix who are fit for surgery, defined as having relatively low risk of adverse outcomes or postoperative mortality and morbidity. In patients without high-risk CT findings, either appendectomy or antibiotics can be considered as first-line therapy. In unfit patients without these high-risk CT findings, the antibiotics-first approach is recommended, and surgery may be considered if antibiotic treatment fails. In unfit patients with high-risk CT findings, perioperative risk assessment as well as patient preferences should be considered.

CONCLUSIONS AND RELEVANCE

Acute appendicitis affects 96.5 to 100 people per 100 000 adults per year worldwide. Appendectomy remains first-line therapy for acute appendicitis, but treatment with antibiotics rather than surgery is appropriate in selected patients with uncomplicated appendicitis.

Sonographic diagnosis of appendicitis: A pictorial essay and a new diagnostic maneuver

While many cases of appendicitis are easy to diagnose clinically, a significant number need further workup in the form of imaging. Ultrasound and CT are both used extensively to diagnose or exclude appendicitis, or arrive at an alternate diagnosis. Ultrasound has many advantages but can be a difficult modality to use due to, among other reasons, the anatomical variations in appendicial location. The true retrocolic appendix is particularly difficult to diagnose with ultrasound. This pictorial essay examines the ultrasound features of normal and diseased appendix and proposes a new examining station, the prone view, for visualizing true retrocolic appendicitis.

Correlating Abdominal Wall Thickness and Body Mass Index to Predict Usefulness of Right Lower Quadrant Ultrasound for Evaluation of Pediatric Appendicitis

OBJECTIVES

To inform selective and efficient use of appendix ultrasound (US) beyond adult parameters of body mass index (BMI) of less than 25 kg/m, we correlate abdominal wall thickness (AWT) with age and BMI to generate parameters for male and female children. Information presented in chart format can aid in the decision to utilize US for the evaluation of appendicitis.

METHODS

In this observational study, 1600 pediatric computed tomography scans of the abdomen and pelvis were analyzed to obtain measurements of AWT in the right lower quadrant. Measurements were correlated by patient age, BMI, and sex. Results and consensus-based recommendations were presented in chart format with color-coded groupings to allow for convenient referencing in the clinical setting.

RESULTS

One thousand four hundred eighty-eight computed tomography scans and AWT measurements were included. All age groups with BMI of less than 25 kg/m and all male and female groups younger than 6 years regardless of BMI had median AWT of less than 4 cm resulting in strong recommendation for US. Males older than 6 years and all female age groups with BMI of greater than 30 kg/m and female older than 15 years and BMI of greater than 25 kg/m had AWT of more than 5 cm resulting in low recommendation for US.

CONCLUSIONS

While the BMI cutoff standard of less than 25 kg/m for usefulness of appendix US holds in the adult population, our data expand the acceptable range in children younger than 9 years regardless of BMI and male children with BMI up to 30 kg/m. Female children younger than 15 years with a BMI up to 30 kg/m may also be amenable to right lower quadrant US based on AWT. These parameters inform selective and efficient use of US for appendix evaluation.

Variations and morphometric features of the vermiform appendix: A systematic review and meta-analysis of 114,080 subjects with clinical implications

Determining the true and indisputable data regarding the vermiform appendix (VA) morphology is of a great clinical interest. The aim of this study was to provide the best evidence-based anatomical overview of the variations in location and size of VA using a systematic and meta-analytical approach. A systematic review with meta-analysis was performed of studies reporting variants of the location and morphometric data regarding the VA. The MEDLINE/PubMed, ScienceDirect, EMBASE, BIOSIS, SciELO, and Web of Science databases were thoroughly searched throughout June 2018. The reported locations of the body of the VA were re-classified into a new, standardized classification system divided into nine categories. The AQUA tool was used to assess the quality of included studies. The research was conducted following PRISMA guidelines and registered at PROPSERO database. Our meta-analysis included 242 studies (n = 114,080). Overall, the VA was most commonly found in the retrocecal location (32.1%, 95%CI: 29.2-35.1), followed by the pelvic (28.5%, 95%CI: 26.7-30.4) and ileal (14.5%, 95%CI: 11.8-17.7) locations. Subjects without known appendiceal pathologies had significantly smaller VA outer diameters (5.84 mm, 95%CI: 5.68-5.99) than patients diagnosed with acute appendicitis (10.64 mm, 95%CI: 10.14-11.15). The overall pooled mean length of the VA was 80.29 mm (95%CI: 76.68-83.89). Significant differences were found in size of the VA between imaging modalities. The results obtained from this evidence-based anatomy study will improve the clinical understanding of the VA anatomy, which in turn will have major implications for clinical practice. Clin. Anat. 32:85-98, 2019. © 2019 Wiley Periodicals, Inc.

Diagnostic Accuracy of Abdominal Ultrasonography in Pediatric Acute Appendicitis

OBJECTIVE

To evaluate the diagnostic accuracy of ultrasonography in pediatric acute appendicitis.

METHODS

In this cross-sectional study, 230 children aged 5-15 years with the diagnosis of acute appendicitis were studied. This study included the evaluation of demographic indices, ultrasound findings at diagnosis, and then comparing the results with the description of the patient's procedure and the pathology report of these patients. Patients who did not undergo ultrasound before surgery or their ultrasound did not include the evaluation of appendicitis or their pathologic report was not available were excluded.

RESULTS

Overall, we have included a total number of 230 children with clinical diagnosis of acute appendicitis among whom there were 121 (52.6%) girls and 109 (47.4%) boys with mean age of 11.44 ± 2.90 years. Preoperative ultrasound report showed that 51.3% were normal and 48.7% had acute appendicitis. 34.8% had normal appendix and 65.2% had a pathological diagnosis of acute appendicitis. The sensitivity and specificity of ultrasound in these children were 58% and 68%, respectively. Positive and negative predictive values ​​were 77% and 46%, respectively. The area under curve (AUC) was 0.853 (CI 95% 0.788-0.917) indicating a test with moderate accuracy.

CONCLUSION

According to the obtained results, abdominal ultrasonography is of acceptable diagnostic accuracy in pediatric patients with acute appendicitis. The use of auxiliary techniques in ultrasound would increase the sensitivity and specificity in the diagnosis of acute appendicitis in children.

A pictorial essay of the most atypical variants of the vermiform appendix position in computed tomography with their possible clinical implications

Purpose

The tip of the appendix may be located in various areas of the abdominal cavity due to its variable length and/or the changeable position of the caecum. Although in the case of an atypical position the tip is usually located behind the caecum, there are possible locations that occur very rarely. Therefore, in the case of appendicitis the symptoms may lead to the wrong diagnosis. The aim of this study is to present the most atypical locations of the tip of the appendix found on CT (computed tomography) scans and thus help to avoid misdiagnoses.

Imaging findings

The most unusual locations of the tip of the appendix found in healthy subjects included: left inferior quadrant, along the lower edge of the liver near the gallbladder and the right kidney, the tip touching the duodenum, the rectum or appendages, and a long appendix located in the scrotum as the content of a hernia. In these positions, appendicitis may mimic acute diverticulitis, cholecystitis, duodenal ulcer, duodenitis, enteritis, or adnexal or testis pathologies.

Conclusions

It is important to be aware of atypical locations of the appendix because appendicitis in an unusual area may mimic other acute abdominal diseases and delay the proper treatment.

Visibility of Normal Appendix on CT, MRI, and Sonography: A Systematic Review and Meta-Analysis

OBJECTIVE

The purpose of the present study is to assess the visibility of the normal appendix on CT, MRI, or ultrasound (US) images of a healthy population.

MATERIALS AND METHODS

The MEDLINE and EMBASE databases were searched to identify articles on the rates of detection of a normal appendix on CT, MRI, or US that appeared in the literature published up to January 20, 2017. Pooled detection rates were assessed using random-effects modeling, and rates associated with different imaging modalities were compared. Meta-regression analyses were performed to assess factors influencing detection rates and heterogeneity.

RESULTS

Thirty-two studies (21 CT studies with 5296 patients, 7 MRI studies with 600 patients, and 4 US studies with 1221 patients) were included in our meta-analysis. The overall normal appendix detection rate tended to be highest for CT (84%), followed by US (71%) and MR (69%), but no statistically significant differences were noted (for CT vs MRI, p = 0.16; for CT vs US, p = 0.23; and for MRI vs US, p = 0.91). Meta-regression analyses of the appendix detection rate with CT revealed that the year of publication of the study, the number of CT channels, and slice thickness affected study heterogeneity.

CONCLUSION

Normal appendixes seemed to be more visible on CT than on MRI or US, although this finding did not have statistical significance. With respect to CT, detection of normal appendixes was significantly better when more channels and thinner slices were used.

A Pediatric Foreign Body Appendicitis Can Cause a Pitfall in Imaging

Although foreign body (FB) ingestion is common in childhood, most cases do not have any clinical significance. Radiologic evaluation is crucial to determine the exact location of a persistent foreign body because it dictates the therapeutic approach. In this case report, we present a child with appendiceal perforation caused by a FB and emphasize pitfalls in preoperative imaging assessment. A 3-year-old boy presented with subtle abdominal pain duration for three months. The preoperative imaging examinations were consistent with an intraluminal metallic pin. However, the operative findings and postoperative pathological examination showed that the pin perforated the appendiceal wall, causing chronic inflammatory changes with an omental reaction around the extraluminal part of the pin. The patient underwent appendectomy with an uneventful course. Foreign body is a rare cause of appendiceal perforation with resultant appendicitis. Imaging may reveal some clues regarding the location, but the interpretation of radiologic data could be quite challenging.

The Use of Ultrasonography to Assess Patients with Right Lower Quadrant Pain in the Emergency Department

Acute appendicitis is always a clinical challenge to emergency physicians. Clinical examination or blood tests are notoriously unreliable in making the diagnosis, especially in the early phase of the disease. Computed tomogram can facilitate the diagnosis, however it is usually not easily accessible to emergency physicians. Bedside ultrasonography is now frequently used by emergency physicians in various situations for the assessment of patients. This study aimed at exploring the potential use of bedside ultrasonography in the diagnosis of acute appendicitis in patients presenting with right lower quadrant abdominal pain.

Care of Acute Gastrointestinal Conditions in the Observation Unit

The Emergency Department Observation Unit (EDOU) provides a viable alternative to inpatient admission for the management of many acute gastrointestinal conditions with additional opportunities of reducing resource utilization and reducing radiation exposure. Using available evidence-based criteria to determine appropriate patient selection, evaluation, and treatment provides higher-quality medical care and improved patient satisfaction. Discussions of factors involved in creating an EDOU capable of caring for acute gastrointestinal conditions and clinical protocol examples of acute appendicitis, gastrointestinal hemorrhage, and acute pancreatitis provide a framework from which a successful EDOU can be built.

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.

Abdominal wall thickness is not useful to predict appendix visualization on sonography in adult patients with suspected appendicitis

PURPOSE

To evaluate clinical and imaging factors for potential use in predicting appendix visualization on sonography (US) of adult patients with suspected appendicitis.

METHODS

All adult patients who underwent appendiceal US from January through June 2010 were included in this retrospective study. Clinicopathological records were reviewed for age, sex, weight, body mass index, symptom duration, Alvarado score, surgicopathologic diagnosis, and disposition. Imaging records were collated for abdominal thicknesses, appendix visualization, and impression. The definitive diagnosis was made on pathologic evaluation.

RESULTS

Eighty-six patients (68 women; median age, 35.5 years; age range, 16-86 years) met the inclusion criteria. The patients' mean weight was 56 kg; body mass index, 22.4; duration of symptoms, 24 hours; and Alvarado score, 6.5. Of the 86 patients, 37 (43%) had appendicitis. The appendix was visualized on US in 27 patients, of whom 25 had appendicitis; the appendix was not visualized in 59 patients, of whom 12 had appendicitis. There was no correlation between the clinical factors studied, the abdominal fat thickness (10.9 versus 10.7 mm; p = 0.90), or the abdominal wall thickness (16.9 versus 17.3 mm; p = 0.76) between patients with a US-visualized appendix and those whose appendix was not visualized on US.

CONCLUSIONS

Abdominal thicknesses and other factors are not predictive of appendix visualization on US examination of adults with suspected appendicitis.

Variation in Anatomical Position of Vermiform Appendix among Iranian Population: An Old Issue Which Has Not Lost Its Importance

Vermiform appendix has diverse anatomical positions, lengths, and conditions of mesoappendix. Knowing the exact anatomical position of vermiform appendix is important in view of surgeons for on-time diagnosis and management of acute appendicitis. The aim of present study is determination of these characteristics of vermiform appendix among Iranian population. The present study was conducted on 200 bodies, selected from the dead bodies that had been referred to local bureau of legal medicine, Zenjan province, Iran, for medicolegal autopsy since 21 Mar 2010 to 21 Mar 2011. According to the results, the anatomical positions of the appendix were pelvic, subcecal, retroileal, retrocecal, ectopic, and preileal in 55.8%, 19%, 12.5%, 7%, 4.2%, and 1.5% of the bodies, respectively. The mean length of vermiform appendix was 91.2 mm and 80.3 mm in men and women, respectively. Mesoappendix was complete in 79.5% of the bodies. No association was found between sex and anatomical position of vermiform appendix. Anterior anatomical position was the most common position for vermiform appendix. It is inconsistent with most related reports from western countries. It might be possible that some factors, such as race, geographical changes, and dietary habits, play roles in determining the position of vermiform appendix.

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.

Imaging acute appendicitis: state of the art

The goal of this review is to present the state of the art in imaging tests for the diagnosis of acute appendicitis. Relevant publications regarding performance and advantages/disadvantages of imaging modalities for the diagnosis of appendicitis in different clinical situations were reviewed. Articles were extracted from a computerized database (MEDLINE) with the following activated limits: Humans, English, core clinical journals, and published in the last five years. Reference lists of relevant studies were checked manually to identify additional, related articles. Ultrasound (US) examination should be the first imaging test performed, particularly among the pediatric and young adult populations, who represent the main targets for appendicitis, as well as in pregnant patients. A positive US examination for appendicitis or an alternative diagnosis of possible gastrointestinal or urological origin, or a negative US, either showing a normal appendix or presenting low clinical suspicion of appendicitis, should lead to a final diagnosis. A negative or indeterminate examination with a strong clinical suspicion of appendicitis should be followed by a computed tomography (CT) scan or alternatively, a magnetic resonanace imaging (MRI) scan in a pregnant patient. A second US examination in a patient with persistent symptoms, especially if the first one was performed by a less experienced imaging professional, is a valid alternative to a CT.

Sonographic appearance of the normal appendix in children

PURPOSE

To determine the visualization rate of the appendix in children without appendicitis and investigate factors affecting it.

METHODS

Between January 2010 and April 2010, 205 consecutive children (103 boys and 102 girls; mean age: 9 years) without clinical signs of appendicitis were examined by ultrasound (US). The location of appendix was determined. The outer appendiceal diameter with and without compression was measured and the content of the lumen and mural vascularity on color Doppler was determined. The appendix diameter was correlated with age, weight, and height using Pearson correlation. For age, weight, and height, children with a visualized appendix were compared with those in whom the appendix was not visualized using Student's t test.

RESULTS

The appendix was visualized in 142 of 205 (69.3%) children. The mean diameters of the appendices without and with compression were 4.2 ± 0.9 mm and 3.5 ± 0.8 mm, respectively, with 53.5% of the appendices in the mid-pelvic location. Appendiceal lumen was empty in 35.2% of children. Only one appendix showed mural vascularity on color Doppler. There was no correlation between the diameter (compressed or noncompressed) of the appendix and age, weight, or height. Mean ± SD age, weight, and height of the children with a visualized appendix (8.6 ± 0.3 years, 29.9 ± 0.9 kg, 127.7 ± 1.7 cm, respectively) were significantly lower than those in children with a nonvisualized appendix (9.8 ± 0.4 years, 36.0 ± 1.8 kg, 134.7 ± 2.5 cm, respectively) (p < 0.05 for all three parameters).

CONCLUSION

In the majority of the children, the appendix can be visualized with US. Age, weight, and height affect the visualization rate of the normal appendix.

Sonography of acute right lower quadrant pain: importance of increased intraabdominal fat echo

OBJECTIVE

The purpose of our study was to assess the diagnostic usefulness of increased intraabdominal fat echo during the sonographic evaluation of patients with acute right lower quadrant (RLQ) pain.

SUBJECTS AND METHODS

A total of 328 consecutive patients (132 male and 196 female; mean age, 28+/-15 [SD] years) with acute RLQ pain prospectively underwent transabdominal sonography by one of three experienced radiologists. The radiologists prospectively graded intraabdominal fat echo using a 3-point scale: 1, normal; 2, slight increase; and 3, marked and diffuse increase. Final diagnoses were made using surgical or pathologic findings or by clinical follow-up. Of the 328 patients, 11 were lost to follow-up and excluded from analysis. Sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of increased intraabdominal fat echo were calculated for a positive final diagnosis.

RESULTS

Final diagnoses were negative (n=103), acute appendicitis (n=137), right colonic diverticulitis (n=18), mesenteric lymphadenitis (n=13), enteritis (n=26), and others (n=20). Grades of intraabdominal fat echo were grade 1 (n=158), grade 2 (n=35), and grade 3 (n=124). Overall, fat echo grades 2 or 3 were more frequently observed in patients with a positive final diagnosis (73% [157/214] vs 2% [2/103], p<0.001) than in those with a negative final diagnosis. Sensitivity, specificity, accuracy, PPV, and NPV of increased intraabdominal fat echo for a positive final diagnosis were 73%, 98%, 81%, 99%, and 64%. Increased intraabdominal fat echo was documented in 89% (122/137) of cases of acute appendicitis and in 100% (18/18) of cases of right colonic diverticulitis.

CONCLUSION

An increased intraabdominal fat echo on sonography is highly specific for the presence of RLQ inflammatory disease.

Diagnosing acute appendicitis in adults: accuracy of color Doppler sonography and MDCT compared with surgery and clinical follow-up

OBJECTIVE

The objective of our study was to evaluate the accuracy of color Doppler sonography and contrast-enhanced MDCT in the diagnosis of acute appendicitis in adults and their utility as a triage tool in lower abdominal pain.

MATERIALS AND METHODS

We reviewed the medical records of 420 consecutive adult patients, 271 women and 149 men, 18 years old or older, referred from the emergency department to sonography examination for clinically suspected acute appendicitis between January 2003 and June 2006. Patients underwent sonography of the right upper abdomen and pelvis followed by graded compression and color Doppler sonography of the right lower quadrant. CT was performed in 132 patients due to inconclusive sonography findings or a discrepancy between the clinical diagnosis and the sonography diagnosis. Sonography and CT reports were compared with surgery or clinical follow-up as the reference standard. Statistical analyses were performed by Pearson's chi-square test and cross-tabulation software.

RESULTS

Sonography and CT correctly diagnosed acute appendicitis in 66 of 75 patients and in 38 of 39 patients, respectively, and correctly denied acute appendicitis in 312 of 326 and in 92 of 92 patients. Sonography was inconclusive in 17 of 418 cases and CT, in one of 132 cases. Sonography and CT allowed alternative diagnoses in 82 and 42 patients, respectively. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for sonography were 74.2%, 97%, 88%, 93%, and 92%, respectively, and for CT, 100%, 98.9%, 97.4%, 100%, and 99%.

CONCLUSION

Sonography should be the first imaging technique in adult patients for the diagnosis of acute appendicitis and triage of acute abdominal pain. CT should be used as a complementary study for selected cases.