Imaging of acute appendicitis: US as the primary imaging modality

Accuracy of point-of-care ultrasound in the diagnosis of acute appendicitis in a pediatric emergency department

PURPOSE

To investigate the accuracy of point-of-care ultrasound (PoCUS) in diagnosing acute appendicitis in children; to evaluate the concordance between PoCUS performed by a pediatric emergency physician (PedEm) and ultrasonography (US) performed by a radiologist; to draw a "learning curve."

METHODS

We prospectively enrolled children aged 0-14 years old led to the Emergency Department of Regina Margherita Children's Hospital, from January 2021 to June 2021, with suspected acute appendicitis. PoCUS was performed by a single trained PedEm, blindly to the radiologist's scan. A "self-assessment score" and the "time of duration of PoCUS" were recorded for each patient. Final diagnosis of appendicitis was made by a pediatric surgeon.

RESULTS

We enrolled 62 children (2-14 years). Overall sensitivity of PoCUS was 88%, specificity 90%; PPV 90.6%, and NPV 86.6%. Global concordance between the PedEm and the radiologist was good/excellent (k 0.74). The mean duration of PoCUS significantly decreased during the study period, while the self-assessment score increased.

CONCLUSION

This is a preliminary study that shows the effectiveness of PoCUS in diagnosing acute appendicitis; furthermore, it shows how the PedEm's performance may improve over time. The learning curve showed how the experience of the PedEm affects the accuracy of PoCUS.

Combined Diagnostic Accuracy of Total Leukocyte Count, Neutrophil Count, and Ultrasonography for the Diagnosis of Acute Appendicitis

Acute appendicitis is a common surgical emergency that classically presents with right lower abdominal pain and tenderness on palpation. The diagnosis is often based on clinical examination in order to avoid the complications of surgery delay, yielding a high rate of negative appendectomies. Ultrasonography is a regularly used modality for establishing the diagnosis, whereas abdominal computed tomography (CT) is often used in sonologically equivocal cases. Other parameters include total leukocyte count, granulocytes, C-reactive protein (CRP), leukocyte elastase activity, D-lactate, phospholipase A2, and interleukin-6 (IL-6). We conducted a prospective study to assess the combined accuracy of total leukocyte count, neutrophil count, and ultrasound as an integrated diagnostic tool. The results of these investigations were tabulated and compared to histopathological evidence of acute appendicitis on biopsy (taken as the gold standard) to calculate sensitivity, specificity, positive predictive value, and negative predictive value. Combined sensitivity and specificity were calculated using cross-tabulation, whereas diagnostic accuracy was estimated from the receiver operating curve (ROC) at the optimal cut-off point. The results showed that the absence of inflammatory findings on ultrasound and normal blood parameters (total leukocyte count and neutrophil count) have a high combined diagnostic accuracy and appendicitis may be ruled out.

Suspected appendicitis pathway continues to lower CT rates in children two years after implementation

BACKGROUND

We implemented a protocol to evaluate pediatric patients with suspected appendicitis using ultrasound as the initial imaging modality. CT utilization rates and diagnostic accuracy were evaluated two years after pathway implementation.

METHODS

This was a retrospective observational study of patients <18 years evaluated for suspected appendicitis. CT rates were compared before and after implementation of the protocol, and monthly CT rates were calculated to assess trends in CT utilization.

RESULTS

CT use decreased significantly following pathway implementation from 94.2% (130/138) to 27.5% (78/284; p < 0.001). Linear regression of monthly CT utilization demonstrated that CT rates continued to trend down two years after pathway implementation. Adherence to the pathway was 89.8% (255/284). Negative appendectomy rate was 2.4% (2/85) in the post-pathway period.

CONCLUSIONS

Adherence to a pathway designed to evaluate pediatric patients with suspected appendicitis using ultrasound as the primary imaging modality has led to a sustained decrease in CT use without compromising diagnostic accuracy.

Importance of Clinical Decision Making by Experienced Pediatric Surgeons When Children Are Suspected of Having Acute Appendicitis: The Reality in a High-Volume Pediatric Emergency Department

OBJECTIVE

The aim of the present study was to compare the pediatric appendicitis score (PAS), the Alvarado score (AS), white blood cell count (WBC), absolute neutrophil count (ANC), C-reactive protein (CRP) level, procalcitonin level, and ultrasound (US) data, with the appendectomy decisions of pediatric surgeons diagnosing acute appendicitis (AA) in a real-life setting; this was a top-level, high-volume pediatric emergency department (PED) in a developing country.

METHODS

The study was conducted prospectively between January 2012 and June 2013 in the PED of the Tepecik Teaching and Research Hospital in Izmir, Turkey. The study was observational in nature; no attempt was made to influence indications for exploration or the timing thereof. Children aged 4 to 18 years presenting to the PED on suspicion of AA were included. The WBC, ANC, CRP level, and procalcitonin level were measured, and US was performed on all patients on admission. The PAS and AS were calculated. An operative decision was made by each pediatric surgeon who had the results of laboratory and radiological tests. The criterion standard for AA was histopathological assessment.

RESULTS

Upon receiver operating curve (ROC) analysis, the areas under the ROCs (AUROCs) of the WBC, ANC, CRP level, procalcitonin level, US positivity, PAS, AS, and decisions of pediatric surgeons supported by laboratory and US data were 0.734, 0.741, 0.671, 0.675, 0.670, 0.831, 0.794, and 0.910, respectively. When US data were employed only in cases with PASs 4 to 7, the sensitivity increased but specificity decreased. The sensitivity and specificity of pediatric surgical decisions were 100% and 82.50%, respectively. The difference between the PAS AUROC and the pediatric surgeon decision-making AUROC was significant (P = 0.0393; 95% confidence interval, 0.0470-0.226).

CONCLUSIONS

Good pediatric surgical decision making supported by laboratory and US data for those suspected of AA may be the most effective diagnostic tool in a high-volume PED in a developing country.

Evaluating the risk of appendiceal perforation when using ultrasound as the initial diagnostic imaging modality in children with suspected appendicitis

BACKGROUND

Ultrasound scan has gained attention for diagnosing appendicitis due to its avoidance of ionizing radiation. However, studies show that ultrasound scan carries inferior sensitivity to computed tomography scan. A non-diagnostic ultrasound scan could increase the time to diagnosis and appendicectomy, particularly if follow-up computed tomography scan is needed. Some studies suggest that delaying appendicectomy increases the risk of perforation.

OBJECTIVE

To investigate the risk of appendiceal perforation when using ultrasound scan as the initial diagnostic imaging modality in children with suspected appendicitis.

METHODS

We retrospectively reviewed 1411 charts of children ≤17 years old diagnosed with appendicitis at two urban academic medical centers. Patients who underwent ultrasound scan first were compared to those who underwent computed tomography scan first. In the sub-group analysis, patients who only received ultrasound scan were compared to those who received initial ultrasound scan followed by computed tomography scan. Main outcome measures were appendiceal perforation rate and time from triage to appendicectomy.

RESULTS

In 720 children eligible for analysis, there was no significant difference in perforation rate between those who had initial ultrasound scan and those who had initial computed tomography scan (7.3% vs. 8.9%, p = 0.44), nor in those who had ultrasound scan only and those who had initial ultrasound scan followed by computed tomography scan (8.0% vs. 5.6%, p = 0.42). Those patients who had ultrasound scan first had a shorter triage-to-incision time than those who had computed tomography scan first (9.2 (IQR: 5.9, 14.0) vs. 10.2 (IQR: 7.3, 14.3) hours, p = 0.03), whereas those who had ultrasound scan followed by computed tomography scan took longer than those who had ultrasound scan only (7.8 (IQR: 5.3, 11.6) vs. 15.1 (IQR: 10.6, 20.6), p < 0.001). Children < 12 years old receiving ultrasound scan first had lower perforation rate (p = 0.01) and shorter triage-to-incision time (p = 0.003).

CONCLUSION

Children with suspected appendicitis receiving ultrasound scan as the initial diagnostic imaging modality do not have increased risk of perforation compared to those receiving computed tomography scan first. We recommend that children <12 years of age receive ultrasound scan first.

Can common serum biomarkers predict complicated appendicitis in children?

PURPOSE

As appendicitis in children can be managed differently according to the severity of the disease, we investigated whether commonly used serum biomarkers on admission could distinguish between simple and complicated appendicitis.

METHODS

Admission white blood cell (WBC), neutrophil (NEU), and C-reactive protein (CRP) levels were analysed by ROC curve, and Kruskal-Wallis and contingency tests. Patients were divided according to age and histology [normal appendix (NA), simple appendicitis (SA), complicated appendicitis (CA)].

RESULTS

Of 1197 children (NA = 186, SA = 685, CA = 326), 7% were <5 years, 55% 5-12, 38% 13-17. CA patients had higher CRP and WBC levels than NA and SA (p < 0.0001). NEU levels were lower in NA compared to SA or CA (p < 0.0001), but were similar between SA and CA (p = 0.6). CA patients had higher CRP and WBC levels than SA patients in 5-12- (p < 0.0001) and 13-17-year groups (p = 0.0075, p = 0.005), but not in <5-year group (p = 0.72, p = 0.81). We found CRP >40 mg/L in 58% CA and 37% SA (p < 0.0001), and WBC >15 × 10⁹/L in 58% CA and 43% SA (p < 0.0001).

CONCLUSIONS

Admission CRP and WBC levels may help the clinician predict complicated appendicitis in children older than 5 years of age. Early distinction of appendicitis severity using these tests may guide caregivers in the preoperative decision-making process.

Ultrasound, computed tomography or magnetic resonance imaging - which is preferred for acute appendicitis in children? A Meta-analysis

BACKGROUND

There is no established consensus about the relative accuracies of US, CT and MRI in childhood appendicitis.

OBJECTIVE

To compare, through meta-analysis, the accuracies of US, CT and MRI for clinically suspected acute appendicitis in children.

MATERIALS AND METHODS

PubMed, Embase, Web of Science and the Cochrane Library were searched. After study selection, data extraction and quality assessment, the sensitivity, specificity and the area under the curve of summary receiver operating characteristic were calculated and compared.

RESULTS

Twenty-seven articles including 29 studies met the inclusion criteria, including 19 studies (9,170 patients) of US, 6 studies (928 patients) of CT and 4 studies (990 patients) of MRI. The analysis showed that the area under the receiver operator characteristics curve of MRI (0.995) was a little higher than that of US (0.987) and CT (0.982; P > 0.05).

CONCLUSION

US, CT and MRI have high diagnostic accuracies of clinically suspected acute appendicitis in children overall with no significant difference.

Secondary signs may improve the diagnostic accuracy of equivocal ultrasounds for suspected appendicitis in children

INTRODUCTION

Ultrasound (US) is the preferred imaging modality for evaluating appendicitis. Our purpose was to determine if including secondary signs (SS) improve diagnostic accuracy in equivocal US studies.

METHODS

Retrospective review identified 825 children presenting with concern for appendicitis and with a right lower quadrant (RLQ) US. Regression models identified which SS were associated with appendicitis. Test characteristics were demonstrated.

RESULTS

530 patients (64%) had equivocal US reports. Of 114 (22%) patients with equivocal US undergoing CT, those with SS were more likely to have appendicitis (48.6% vs 14.6%, p<0.001). Of 172 (32%) patients with equivocal US admitted for observation, those with SS were more likely to have appendicitis (61.0% vs 33.6%, p<0.001). SS associated with appendicitis included fluid collection (adjusted odds ratio (OR) 13.3, 95% confidence interval (CI) 2.1-82.8), hyperemia (OR=2.0, 95%CI 1.5-95.5), free fluid (OR=9.8, 95%CI 3.8-25.4), and appendicolith (OR=7.9, 95%CI 1.7-37.2). Wall thickness, bowel peristalsis, and echogenic fat were not associated with appendicitis. Equivocal US that included hyperemia, a fluid collection, or an appendicolith had 96% specificity and 88% accuracy.

CONCLUSION

Use of SS in RLQ US assists in the diagnostic accuracy of appendicitis. SS may guide clinicians and reduce unnecessary CT and admissions.

An Imaging Diagnostic Protocol in Children with Clinically Suspected Acute Appendicitis

The objective of the present study is to evaluate a new diagnostic strategy using clinical findings followed by ultrasound (US) and, in selected cases, MRI. This study included 166 children presenting signs and symptoms suggesting acute appendicitis. Cases classified as suggesting appendicitis according to clinical exams had to be referred to surgery, whereas the other cases were discharged. Unclear cases were evaluated using US. If the US results were considered inconclusive, patients underwent MRI. Of the 166 patients, 78 (47%) had acute appendicitis and 88 (53%) had other diseases. The strategy under study had a sensitivity of 96 per cent, specificity of 100 per cent, positive predictive value of 100 per cent, negative predictive value of 97 per cent, and accuracy of 98 per cent. Eight patients remained undiagnosed and underwent MRI. After MRI two girls presented normal appendixes and were discharged. One girl had an enlarged appendix on MRI and appendicitis could have been confirmed by surgery. In the other five patients, no other sign of the disease was detected by MRI such as an inflammatory mass, free fluid or an abscess in the right iliac fossa. All of them were discharged after clinical observation. In the vast majority of cases the correct diagnosis was reached by clinical and US examinations. When clinical assessment and US findings were inconclusive, MRI was useful to detect normal and abnormal appendixes and valuable to rule out other abdominal pathologies that mimic appendicitis.

[Imaging of acute abdomen in childhood and adolescence]

Acute abdominal pain in childhood is a frequent reason for a medical consultation. The main diseases that lead to the clinical situation of acute abdomen show a significant age dependency. It is reasonable to group such ailments into three age categories: (1) the neonatal and infant period, (2) toddlerhood to kindergarten and (3) school age children. The task of the pediatric radiological examination is the differential diagnostic correlation of symptoms to the respective diseases. In children ultrasound is the appropriate method of choice.

Implementing an ultrasound-based protocol for diagnosing appendicitis while maintaining diagnostic accuracy

BACKGROUND

The use of ultrasound to diagnose appendicitis in children is well-documented but not universally employed outside of pediatric academic centers, especially in the United States. Various obstacles make it difficult for institutions and radiologists to abandon a successful and accurate CT-based imaging protocol in favor of a US-based protocol.

OBJECTIVE

To describe how we overcame barriers to implementing a US-based appendicitis protocol among a large group of nonacademic private-practice pediatric radiologists while maintaining diagnostic accuracy and decreasing medical costs.

MATERIALS AND METHODS

A multidisciplinary team of physicians (pediatric surgery, pediatric emergency medicine and pediatric radiology) approved an imaging protocol using US as the primary modality to evaluate suspected appendicitis with CT for equivocal cases. The protocol addressed potential bias against US and accommodated for institutional limitations of radiologist and sonographer experience and availability. Radiologists coded US reports according to the probability of appendicitis. Radiology reports were compared with clinical outcomes to assess diagnostic accuracy. During the study period, physicians from each group were apprised of the interim US protocol accuracy results. Problematic cases were discussed openly.

RESULTS

A total of 512 children were enrolled and underwent US for evaluation of appendicitis over a 30-month period. Diagnostic accuracy was comparable to published results for combined US/CT protocols. Comparing the first 12 months to the last 12 months of the study period, the proportion of children achieving an unequivocal US result increased from 30% (51/169) to 53% (149/282) and the proportion of children undergoing surgery based solely on US findings increased from 55% (23/42) to 84% (92/109). Overall, 63% (325/512) of patients in the protocol did not require a CT. Total patient costs were reduced by $30,182 annually.

CONCLUSION

We overcame several barriers to implementing a US protocol. During the study period our ability to visualize the appendix with US increased and utilization of CT decreased. Our overall diagnostic accuracy with the US-based protocol was comparable to other published results and remained unchanged throughout the study.

Diagnostic accuracy of emergency physician performed graded compression ultrasound study in acute appendicitis: a prospective study

PURPOSE

Accurate early diagnosis of appendicitis can decrease its complications and minimize the mortality, morbidity and costs. This prospective study evaluates the accuracy of bedside emergency physician performed ultrasound study diagnosis in acute appendicitis.

METHODS

Patients who were suspicious to have appendicitis based on their clinical findings were included and underwent emergency physician performed ultrasound study. Then they were followed up until the recognition of final diagnosis based on pathology report or identification of an alternative diagnosis. Ultrasound studies were done by post-graduate year three emergency medicine residents or emergency medicine attending physicians who were attended in a 4 h didactic and practical course and with 7.5 MHz linear probe both in longitudinal and axial axes.

RESULTS

Ninety-seven patients were included and analyzed. 27 (27.8 %) of patients had appendicitis according to the results of emergency physicians performed ultrasound studies. 19 (70.37 %) of them had appendicitis according to their pathologic reports too. Forty-three (44.3 %) of patients had appendicitis according to pathology reports. Only 19 (44.18 %) of them were diagnosed by emergency physicians. Emergency physician performed ultrasound study had a sensitivity of 44.18 %, specificity of 85.18 %, positive predictive value of 70.37 %, negative predictive value of 65.71 % and overall accuracy of 67.01 % in diagnosing appendicitis in patients clinically suspicious to have acute appendicitis.

CONCLUSION

Emergency physician performed bedside ultrasound has an acceptable overall accuracy but its sensitivity is low thus it can help emergency physicians to diagnose the acute appendicitis when used in conjunction with other clinical and para-clinical evaluations but not per se.

Sonography of acute appendicitis and its mimics in children

The diagnosis of acute right lower quadrant pain in a pediatric population is challenging. Acute appendicitis is the most common cause of an acute surgical abdomen. The common mimics of acute appendicitis are acute gastrointestinal and gynecologic diseases. This article reviews the sonographic findings of the spectrum of common acute abdominal emergencies in children with a focus on imaging clues to a specific diagnosis. This awareness can impact on diagnostic accuracy and impact patient management.

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.

Bildgebung

Ergibt sich aus dem pränatalen Ultraschallbefund oder durch klinische Hinweise der Verdacht auf eine Entwicklungsstörung des Darms des Neugeborenen, so ist die Situation am sichersten durch eine Röntgenaufnahme, und zwar des Thorax und Abdomens im Liegen oder im Hängen, zu klären.

Ultrafast 3-T MRI in the evaluation of children with acute lower abdominal pain for the detection of appendicitis

OBJECTIVE

The purpose of this study is to evaluate the feasibility of ultrafast 3-T MRI in the evaluation of children with acute lower abdominal pain for the detection of appendicitis.

SUBJECTS AND METHODS

Forty-two pediatric patients (30 girls and 12 boys; mean age, 11.5 years; age range, 4-17 years) with acute abdominal pain were prospectively studied. Ultrafast 3-T MRI was performed with a three-plane single-shot turbo spin-echo sequence and an axial T2-weighted turbo spin-echo sequence with fat suppression. All scans were performed without sedation or oral or IV contrast agent. Scan times were less than 8 minutes 45 seconds (median, 5 minutes 40 seconds). Patients underwent CT or ultrasound or both as a comparison study to the MRI examination. The MRI, CT, and ultrasound examinations were interpreted independently by four board-certified radiologists who were blinded to patient information, study interpretations, surgical pathologic findings, and final diagnosis.

RESULTS

Twelve of 42 cases of acute appendicitis were detected with 100% sensitivity, 99% specificity, 100% negative predictive value, and 98% positive predictive value, all of which were statistically significant (p < 0.01). The pooled and individual receiver operating characteristic curves for radiologists' interpretation of the diagnosis of acute appendicitis were greater than 0.95 in all cases (p < 0.01)

CONCLUSION

Ultrafast 3-T MRI is a feasible alternative imaging modality for the diagnosis of acute appendicitis in children, particularly in cases where ultrasound is equivocal or nondiagnostic, as an alternative to CT. Ultrafast MRI requires no sedation and no oral or IV contrast agent and has no associated radiation exposure risks.

Visualization of the normal appendix with MR enterography in children

BACKGROUND

Magnetic resonance (MR) imaging may provide a radiation-sparing alternative to CT in diagnosing appendicitis in children in whom US is equivocal. However, comparability with CT in the detection of the appendix remains to be established.

OBJECTIVE

To determine the detection rate of the normal appendix in children on oral and IV contrast-enhanced MRI.

METHODS

MR imaging of 58 patients who had previously undergone MR enterography was retrospectively reviewed. Detection rate, body mass index, age and gender were recorded.

RESULTS

The normal appendix was detected in 28 cases (48%), with greatest detection rate on the axial fast imaging employing steady-state acquisition (FIESTA) sequence. Children in whom the appendix was detected had significantly higher BMI compared to children in whom the appendix was not seen. Neither age nor gender demonstrated a significant association with detection rate.

CONCLUSION

The detection rate of the normal appendix in children on oral and IV contrast-enhanced MRI was 48%, which is comparable to detection rates on CT, as well as to previously reported detection rates on MR imaging with neither oral nor IV contrast agents. These findings may serve to guide the development of MRI protocols for pediatric appendicitis.

A critical evaluation of US for the diagnosis of pediatric acute appendicitis in a real-life setting: how can we improve the diagnostic value of sonography?

BACKGROUND

We have observed that day-to-day use of US for acute appendicitis does not perform as well as described in the literature.

OBJECTIVE

Review the diagnostic performance of US in acute appendicitis with attention to factors that influence performance.

MATERIALS AND METHODS

Retrospective review of all sonograms for acute appendicitis in children from May 2005 to May 2010 with attention to the rate of identification of the appendix, training of personnel involved and diagnostic accuracy.

RESULTS

The appendix was identified in 246/1,009 cases (24.4%), with identification increasing over time. The accuracy of US was 85-91% with 35 false-positives and 54 false-negatives. Pediatric sonographers were significantly better at identifying the appendix than non-pediatric sonographers (P < 0.0001). Increased weight was the only patient factor that influenced identification of the appendix (P = 0.006). CT use was stable over the 5 years but declined in cases where the appendix was identified by US.

CONCLUSION

In day-to-day use, US does not perform as purported in the literature. We do not visualize the appendix as often as we should and false-negative and false-positive exams are too common. To improve the diagnostic performance of this modality, involvement by experienced personnel and/or additional training is needed.

[Usefulness of ultrasonography in children with right iliac fossa pain]

Acute pain in the right iliac fossa is common in children. It can arise from a wide variety of gastrointestinal and genitourinary processes that make up the differential diagnosis with acute appendicitis. In this article, we describe the most representative findings of these processes on ultrasonography. We emphasize the characteristics that enable these processes to be differentiated from acute appendicitis.

Revised ultrasound criteria for appendicitis in children improve diagnostic accuracy

BACKGROUND

Use of CT in the evaluation of suspected appendicitis in children is common. Expanding the use of US would eliminate the radiation exposure associated with CT.

OBJECTIVE

We describe new criteria that improve US's diagnostic accuracy for appendicitis, making it more comparable to CT in terms of sensitivity and specificity.

MATERIALS AND METHODS

We conducted a retrospective review of 304 consecutive patients undergoing US for the diagnosis of appendicitis in our institution during 2006. The sensitivity, specificity and accuracy of the maximal outer diameter (MOD) at various measurements was calculated and compared to pathology results. Additional variables (appendiceal wall thickness, fecalith, hyperemia, fat stranding, free fluid, age and weight) were also evaluated.

RESULTS

The highest sensitivity (98.7%) and specificity (95.4%) were identified when MOD was ≥7 mm or wall thickness was >1.7 mm. These values resulted in correctly classifying 96.6% of cases, with 1 (0.5%) false-negative and 6 (2.9%) false-positive studies. Incorporating secondary signs of appendicitis, age or weight did not alter accuracy.

CONCLUSION

These findings identify new US criteria that compare favorably to CT. In children with suspected appendicitis, using US as the initial imaging study will ultimately lead to improved accuracy, lower cost and the elimination of ionizing radiation exposure.

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.

Update on imaging for acute appendicitis

Acute appendicitis is a common surgical emergency and the diagnosis can often be made clinically; however, many patients present with atypical findings. For these patients, there are multiple imaging modalities available to aid in the diagnosis of suspected appendicitis in an effort to avoid a negative appendectomy. Computed tomography is the test of choice in most patients in whom the diagnosis is not certain. Ultrasonography is particularly useful in children and pregnant women. Magnetic resonance imaging is recommended when ultrasonography is inconclusive. Appropriate use of these imaging studies avoids delays in treatment, prolonged hospitalization, and unnecessary surgery.

Single-centre experience of radiation exposure in acute surgical patients: assessment of therapeutic impact and future recommendations

BACKGROUND

Radiological investigations have become a key adjunct in patient management and consequently radiation exposure to patients is increasing. The study objectives were to examine the use of radiological investigations in the management of acute surgical patients and to assess whether a guideline-based radiation exposure risk/benefit analysis can aid in the choice of radiological investigation used.

METHODS

A prospective observational study was completed over a 12-week period from April to July 2008 for all acute surgical admissions. Data recorded included demographics, clinical presentation, differential diagnosis, investigations, surgical interventions, and final clinical outcome. The use of radiological investigative modalities as an adjunct to clinical assessment was then evaluated against The Royal College of Radiologists (RCR) guidelines.

RESULTS

A total of 380 acute surgical admissions (M = 174, F = 185, children = 21) were assessed during the study period. Seven hundred thirty-four radiological investigations were performed with a mean of 1.93 investigations per patient. Based on the RCR guidelines, 680 (92.6%) radiological investigations were warranted and included 142 CT scans (19.3%), 129 chest X-rays (17.6%), and 85 abdominal X-rays (11.6%). Clinically, radiological imaging complemented surgical management in 326 patients (85.8%) and the management plan remained unchanged for the remaining 54 patients (14.2%). This accounted for an average radiation dose of 4.18 millisievert (mSv) per patient or 626 days of background radiation exposure. CT imaging was responsible for the majority of the radiation exposure, with a total of 1310 mSv (82.6%) of the total radiation exposure being attributed to CT imaging in 20.8% of acute admissions. Subgroup analysis demonstrated that 92.8% of the CT scans performed were appropriate.

CONCLUSION

Radiation exposure was generally low for the majority of acute surgical admissions. However, it is recommended that CT imaging requests be evaluated carefully, particularly for patients with clinically confirmed pathologies and in younger women.

Incidence and significance of inconclusive results in ultrasound for appendicitis in children and teenagers

PURPOSE

Frustratingly, sonography to assess for appendicitis in children often leads to an inconclusive report (eg, "suspicious for appendicitis") or nonvisualization of the appendix. To aid in planning who to image and how to interpret the results, we investigated whether these 2 results were more frequent in teenagers than preteens and the prevalence of appendicitis associated with each result.

METHODS

We retrospectively reviewed sonographic and surgical findings in patients <18 years (n = 189) referred with clinical suspicion of appendicitis over a 12-month period. Children (≤12.0 years old; n = 86) and teens (>12.0 years old; n = 103) were compared.

RESULTS

Prevalence of appendicitis was 34% in each group, similar to other centres; 0% for those with negative ultrasound reports (0/35), 10% for nonvisualized appendix (8/84), 68% for inconclusive report (15/22), and 85% for positive ultrasound (41/48). Teens were significantly more likely to have an inconclusive ultrasound. Inconclusive reports were because of borderline findings (eg, appendix size near 6 mm; 9/22), body habitus, bowel gas, or unusual findings due in retrospect to perforation. The rate of nonvisualization of the appendix did not vary significantly with age (42% vs 47%).

CONCLUSION

An inconclusive result of ultrasound for appendicitis was significantly more frequent in teens than in preteens and carried a high (68%) likelihood of appendicitis. Conversely, a nonvisualized appendix was equally frequent in teens and preteens, and had a low likelihood of appendicitis (only 10% positive). These findings encourage the use of ultrasound in preteens in particular and can assist interpretation of these common results.

Imaging of acute appendicitis in children: EU versus U.S. ... or US versus CT? A North American perspective

The timing, type, and technique of imaging evaluation of suspected appendicitis in children are all debated. This debate is both local and international. The fact is that choices in imaging evaluation will depend on both local and national influences, which are reasonable and to be expected. There still is a responsibility, though, for those involved with evaluation of patients with possible appendicitis to come to agreement about an appropriate diagnostic pathway that considers standards of care and available resources.

US examination of the appendix in children with suspected appendicitis: the additional value of secondary signs

This study evaluated the additional value of secondary signs in the diagnosing of appendicitis in children with ultrasound. From May 2005 to June 2006, 212 consecutive paediatric patients with suspected appendicitis were examined. Ultrasonographic depiction of the appendix was classified into four groups: 1, normal appendix; 2, appendix not depicted, no secondary signs of appendicitis; 3, appendix not depicted with one of the following secondary signs: hyperechoic mesenteric fat, fluid collection, local dilated small bowel loop; 4, depiction of inflamed appendix. We classified 96 patients in group 1, 41 in group 2, 13 in group 3, and 62 in group 4. Prevalence of appendicitis was 71/212 (34%). Negative predictive values of groups 1 and 2 were 99% and 100%, respectively. Positive predictive values of groups 3 and 4 were 85% and 95%, respectively. In groups 3 and 4, hyperechoic mesenteric fat was seen in 73/75 (97.3%), fluid collections and dilated bowel loops were seen in 12/75 (16.0%) and 5/75 (6.6%), respectively. This study shows that in case of non-visualization of the appendix without secondary signs, appendicitis can be safely ruled out. Furthermore, secondary signs of appendicitis alone are a strong indicator of acute appendicitis.

MR imaging evaluation of the normal appendix in children and adolescents

PURPOSE

To evaluate asymptomatic children and adolescents to determine the rate of detection of the normal appendix at unenhanced magnetic resonance (MR) imaging.

MATERIALS AND METHODS

This study was approved by the medical ethics committees of the authors' institutions, and informed consent was obtained from participants' parents or guardians. Forty asymptomatic volunteers underwent MR imaging to detect the appendix. Mean age (+/- standard deviation) for the 18 boys was 12.8 years +/- 2.4 (range, 9-17 years) and for the 22 girls was 12.7 years +/- 2.7 (range, 8-17 years). The MR imaging protocol consisted of axial T1-weighted fast spin-echo (SE), axial and coronal T2-weighted fast SE, and axial T2-weighted fat-saturated fast SE sequences. Two observers interpreted results independently, and kappa coefficients were calculated to evaluate agreement. The rate of detection was defined as the percentage of times that the appendix was visualized with at least one sequence. Body mass index was recorded for all participants.

RESULTS

The normal appendix was detected by one observer in 19 cases (48%) and by the other in 20 cases (50%). The rate of appendix detection after observers reached a consensus was 48% (95% confidence interval: 32%, 64%). Interobserver agreement for appendix detection was good for most sequences analyzed. The greatest rate of normal appendix detection was found with the axial T2-weighted fast SE sequence (48%).

CONCLUSION

The rate of normal appendix detection in children and adolescents at unenhanced MR imaging was 48%, which is similar to computed tomographic but lower than ultrasonographic detection rates.

[Association of streptococcal pharyngitis with complicated appendicitis]

Streptococcal pharyngitis can be accompanied by right lower abdominal quadrant pain, which often is linked to mesenteric adenitis. We report on a case of such misleading association in a child.

CASE REPORT

A 6-year-old child presented pain in the right lower abdominal quadrant and fever with 39 degrees C temperature for 24 h; clinical examination showed pharyngeal erythema and local abdominal tenderness. Strep-test was positive. Abdominal ultrasound visualized signs of appendicitis. The child was operated on for complicated appendicitis.

COMMENTS

The association of pharyngitis and appendicitis is particularly misleading because mesenteric adenitis is the most common cause of right lower quadrant tenderness in children with pharyngitis.

Current Concepts in Imaging of Appendicitis

Appendicitis is the most common cause of acute abdominal pain requiring surgery. Early diagnosis is crucial to the success of therapy. CT and ultrasound are widely recognized as very useful in the timely diagnosis of appendicitis. MR imaging is emerging as an alternative to CT in pregnant patients and in patients who have an allergy to iodinated contrast material. This article reviews the current imaging methods and diagnostic features of appendicitis.

Emergency Pediatric Imaging: Current Status and Update

Imaging has undergone a major revolution. Many procedures performed 20 years ago are no longer performed and new ones have expanded our ability to diagnose previously hidden conditions and also our knowledge of these conditions. This communication deals both with modern imaging and how it is affecting our evaluation of certain diseases but yet underscores that plain film findings still are important and should not be cast by the wayside in favor of more modern cross sectional imaging.

Ultrasonography in the diagnosis of appendicitis: evaluation by meta-analysis

Objective

We wanted to review the usefulness of ultrasonography (US) for the diagnosis of appendicitis and to evaluate the diagnostic accuracy of US according to patients' and researchers' characteristics.

Materials and Methods

The relevant Korean articles published between 1985 and 2003 were included in this study if the patients had clinical symptoms of acute appendicitis. The histopathologic findings were the reference standard and the data were presented for 2×2 tables. Articles were excluded if patients had no sonographic signs of appendicitis according to graded-compression US. Two reviewers independently extracted the data on study characteristics. The Hasselblad method was used to obtain the combined estimates of sensitivity and specificity for the performance of US.

Results

Twenty-two articles (2,643 patients) fulfilled all inclusion criteria. The estimate of đ calculated by combining the sensitivity and specificity was 2.0054 (95% confidence interval [CI]: 1.8553, 2.1554) by a random effects model. The overall sensitivity and specificity (95% CI) were 86.7% (85.4 to 88.0), and 90.0% (88.9 to 91.2), respectively. According to the subgroup meta-analysis by patients' characteristics, the đ estimate (95% CI) of dominantly younger age, male, and highly clinical suggestive group for US was 2.2388 (1.8758 to 2.6019), 2.7131 (2.2493 to 3.1770), and 2.4582 (1.7387 to 3.1777), respectively. Also, according to subgroup meta-analysis by researchers' characteristics, the đ value (95% CI) for US done by diagnostic radiologists and gray-scale was 2.0195 (1.7942 to 2.2447) and 2.2630 (1.8444 to 2.6815).

Conclusion

This evidence suggests that US may be useful for the diagnosis of acute appendicitis, especially when patients are younger age, male, and highly clinical suggestive.

Emergency pediatric imaging: changes over the years. Part II

Changes over the Years (Part II) deals with the chest, extremities and abdomen. Again the consequence of the rapid expansion of digital, cross-sectional imaging is addressed. With the chest, the plain film still plays a very significant role. Similarly, plain films still are very important in musculoskeletal radiology but ultrasound and MR have made great strides in allowing us to more thoroughly evaluate musculoskeletal disease. One of the greatest advances has been in the evaluation of the acute abdomen where ultrasound and CT have almost replaced the physical examination. All of this has put us into the forefront of medicine and we are now faced with delivering our services and opinions on a 7x24 basis.