Impact of radiologic imaging on the surgical decision-making process in suspected appendicitis in children

Diagnostic Performance of a Staged Pathway for Imaging Acute Appendicitis in Children

INTRODUCTION

The objective of this work is to assess the performance of our staged diagnostic pathway in the evaluation of suspected appendicitis cases in children. The pathway consisted of clinical assessment by the emergency physician, performing initial ultrasound (US), consultation, and clinical reevaluation by the surgery team followed by a repeat focused US scan in inconclusive cases. Computed tomography (CT) was limited to cases where the repeat US remained inconclusive and the clinical reassessment indicated persistent concerns for appendicitis.

METHOD

Retrospective review of the electronic medical records of 206 consecutive children who presented to our emergency department with acute abdominal pain and underwent US examination for suspected appendicitis. The imaging findings, management plan, and surgical outcome (in those who underwent surgery) were reviewed. The diagnostic performance of the initial US, repeat US, and the full imaging protocol were evaluated including the negative appendectomy rate (NAR) and the number of CT scans performed.

RESULTS

Of the 206 cases, 73 (35.4%) had appendicitis. Computed tomography was performed in 9 (4.3%) of 206 cases. The US/CT ratio was 23:1. Our approach showed a diagnostic accuracy of 95.6% (197/206), sensitivity of 97.3% (73/75), specificity of 93.7% (124/133), positive predictive value of 89.0% (73/82), and negative predictive value of 98.7% (82/95). The NAR was 2.7% (2/72). The accuracy of the protocol is higher than that of the initial US alone (61.2%; 126/206) and that of the repeat US (84.2%; 16/19).

CONCLUSION

The strategy of repeating limited focused US followed by CT scan in cases that remain inconclusive has good diagnostic accuracy and reasonable NAR and decreases the number of CT scans.

Useful Ultrasound Findings of Pediatric Patients with Equivocal Results of Appendicitis: Analysis Based on a Structured Report Form

Purpose

Materials and Methods

Results

Conclusion

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.

Clinical utility of magnetic resonance imaging in the evaluation of pregnant females with suspected acute appendicitis

OBJECTIVES

To assess the diagnostic performance of magnetic resonance imaging (MRI) in a large cohort of pregnant females with suspected acute appendicitis and to determine the frequency of non-appendiceal causes of abdominal pain identified by MRI in this population.

METHODS

This HIPAA compliant, retrospective study was IRB-approved and informed consent was waived. 212 MRI exams were performed consecutively on pregnant women aged 17-47 years old suspected of having acute appendicitis; eight exams were excluded and analyzed separately due to equivocal findings or lack of clinical follow up. Radiology reports for the MRI and any preceding ultrasound exams were reviewed as well as the patients' electronic medical record for surgical, pathological, or clinical follow up.

RESULTS

Fifteen (7.3%) of 204 MRI scans were determined to be positive for appendicitis, 14 of which were proven on surgical pathology, and one was found to have ileocecal diverticulitis. Out of the remaining 189 scans, none were subsequently shown to have acute appendicitis either surgically or based on clinical follow up. Negative predictive value (NPV) was 100% and positive predictive value was 93.3%. Sensitivity and specificity were 100% and 99.5%, respectively. Non-appendiceal findings which may have accounted for the patient's abdominal pain were seen in 91 (44.2%) of 189 scans. The most common extra-appendiceal causes of abdominal pain identified on MRI include degenerating fibroids (n = 11), significant hydronephrosis (n = 12), cholelithiasis (n = 6), and pyelonephritis (n = 3).

CONCLUSION

Our large study cohort of pregnant patients confirms MRI to be of high diagnostic value in the workup of acute appendicitis with 100% NPV and sensitivity and 99.5% specificity. Furthermore, an alternative diagnosis for abdominal pain in this patient population can be made in nearly half of MRI exams which are deemed negative for appendicitis.

Searching for certainty: findings predictive of appendicitis in equivocal ultrasound exams

BACKGROUND

Ultrasound (US) is the preferred imaging modality for evaluating suspected pediatric appendicitis. However, borderline appendiceal enlargement or questionable inflammatory changes can confound interpretation and lead to equivocal exams.

OBJECTIVE

The purpose of this study was to determine which findings on equivocal US exams are most predictive of appendicitis.

MATERIALS AND METHODS

All US exams performed for suspected pediatric appendicitis from July 1, 2013, through July 9, 2014, were initially interpreted using a risk-stratified scoring system. Two blinded pediatric radiologists independently reviewed US exams designated as equivocal and recorded the following findings: increased wall thickness, loss of mural stratification, peri-appendiceal fat inflammation, peri-appendiceal fluid, appendicolith and maximum appendiceal diameter. A third pediatric radiologist resolved discrepancies. US features were correlated with the final diagnosis via multivariate analysis.

RESULTS

During the study period, 162/3,750 (4.3%) children had US exams initially interpreted as equivocal (mean age 9.8 +/- 3.8 years). Five outpatients were lost to follow-up. Forty-eight of the remaining 157 (30.6%) children had an operative diagnosis of appendicitis. Findings significantly associated with appendicitis were loss of mural stratification (odds ratio [OR] = 6.7, P=0.035), peri-appendiceal fat inflammation (OR = 10.0, P<0.0001) and appendicolith (OR = 15.8, P=0.025). While appendiceal diameter tended to be larger in patients with appendicitis, the difference was not statistically significant.

CONCLUSION

Loss of mural stratification, peri-appendiceal fat inflammation and an appendicolith are significant predictors of appendicitis in children with otherwise equivocal US exams. While maximum appendiceal diameter is not statistically associated with appendicitis in our study, mean appendiceal diameter of 6.7 mm in those without appendicitis suggests that the customary upper normal limit of 6 mm is too sensitive.

Diagnostic imaging for acute appendicitis: interfacility differences in practice patterns

PURPOSE

To evaluate trends and factors associated with interfacility differences in imaging modality selection in the diagnosis and management of children with suspected acute appendicitis.

METHODS

We conducted a retrospective review of diagnostic imaging selection and outcomes in patients <20 years of age who underwent appendectomy at a single Children's Hospital from June 2008 to June 2013. These results were then compared with those of referring hospitals.

RESULTS

A total of 232 children underwent appendectomy during the study period. Imaging results contributed to diagnostic and management decisions in 95.3 % of cases. CT scan was utilized as first-line imaging in 50 % of cases. CTs were preferentially performed at referring institutions (78 vs. 46 %, p < 0.001). Children were five times more likely to undergo CT at referring institutions (OR = 5.5, CI 3.0-10.2). Adjusting for demographics and Alvarado score, diagnostic imaging choice was independent of patient's clinical status.

CONCLUSION

This study demonstrates that initial presentation to a referring hospital independently predicts the use of CT scan for suspected acute appendicitis. Further efforts should be undertaken to develop a clinical pathway that minimizes radiation exposure in the diagnosis of acute appendicitis, with focus on access to pediatric abdominal ultrasound.

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.

Use and accuracy of diagnostic imaging by hospital type in pediatric appendicitis

OBJECTIVE

Accurate, timely diagnosis of pediatric appendicitis minimizes unnecessary operations and treatment delays. Preoperative abdominal-pelvic computed tomography (CT) scan is sensitive and specific for appendicitis; however, concerns regarding radiation exposure in children obligate scrutiny of CT use. Here, we characterize recent preoperative imaging use and accuracy among pediatric appendectomy subjects.

METHODS

We retrospectively reviewed children who underwent operations for presumed appendicitis at a single tertiary-care children's hospital and examined preoperative CT and ultrasound use with subject characteristics. Preoperative imaging accuracy was compared with postoperative and histologic diagnosis as the reference standard.

RESULTS

Most children (395/423, 93.4%) who underwent an operation for appendicitis during 2009-2010 had preoperative imaging. Final diagnoses included normal appendix (7.3%) and perforated appendicitis (23.6%). In multivariable analysis, initial evaluation at a community hospital versus the children's hospital was associated with 4.4-fold higher odds of obtaining a preoperative CT scan (P = .002), whereas preoperative ultrasound was less likely (odds ratio 0.20; P = .003). Ultrasound and CT sensitivities for appendicitis were diminished for studies performed at community hospitals compared with the children's hospital. Girls were 4.5-fold more likely to undergo both ultrasound and CT scans and were associated with lower ultrasound sensitivity for appendicitis.

CONCLUSIONS

Widespread preoperative imaging did not eliminate unnecessary pediatric appendectomies. Controlling for factors potentially associated with referral bias, a CT scan was more likely to be performed in children initially evaluated at community hospitals compared with the children's hospital. Broadly-applicable strategies to systematically maximize diagnostic accuracy for childhood appendicitis, while minimizing ionizing radiation exposure, are urgently needed.

The effect of abdominal pain duration on the accuracy of diagnostic imaging for pediatric appendicitis

STUDY OBJECTIVE

Advanced imaging with computed tomography (CT) or ultrasonography is frequently used to evaluate for appendicitis. The duration of the abdominal pain may be related to the stage of disease and therefore the interpretability of radiologic studies. Here, we investigate the influence of the duration of pain on the diagnostic accuracy of advanced imaging in children being evaluated for acute appendicitis.

METHODS

A secondary analysis of a prospective multicenter observational cohort of children aged 3 to 18 years with suspected appendicitis who underwent CT or ultrasonography was studied. Outcome was based on histopathology or telephone follow-up. Treating physicians recorded the duration of pain. Imaging was coded as positive, negative, or equivocal according to an attending radiologist's interpretation.

RESULTS

A total of 1,810 children were analyzed (49% boys, mean age 10.9 years [SD 3.8 years]); 1,216 (68%) were assessed by CT and 832 (46%) by ultrasonography (238 [13%] had both). The sensitivity of ultrasonography increased linearly with increasing pain duration (test for trend: odds ratio=1.39; 95% confidence interval 1.14 to 1.71). There was no association between the sensitivity of CT or specificity of either modality with pain duration. The proportion of equivocal CT readings significantly decreased with increasing pain duration (test for trend: odds ratio=0.76; 95% confidence interval 0.65 to 0.90).

CONCLUSION

The sensitivity of ultrasonography for appendicitis improves with a longer duration of abdominal pain, whereas CT demonstrated high sensitivity regardless of pain duration. Additionally, CT results (but not ultrasonographic results) were less likely to be equivocal with longer duration of abdominal pain.

Diagnostic imaging and negative appendectomy rates in children: effects of age and gender

BACKGROUND AND OBJECTIVES

Diagnostic imaging is often used in the evaluation of children with possible appendicitis. The utility of imaging may vary according to a patient's age and gender. The objectives of this study were (1) to examine the use of computed tomography (CT) and ultrasound for age and gender subgroups of children undergoing an appendectomy; and (2) to study the association between imaging and negative appendectomy rates (NARs) among these subgroups.

METHODS

Retrospective review of children presenting to 40 US pediatric emergency departments from 2005 to 2009 (Pediatric Health Information Systems database). Children undergoing an appendectomy were stratified by age and gender for measuring the association between ultrasound and CT use and the outcome of negative appendectomy.

RESULTS

A total of 8 959 155 visits at 40 pediatric emergency departments were investigated; 55 227 children had appendicitis. The NAR was 3.6%. NARs were highest for children younger than 5 years (boys 16.8%, girls 14.6%) and girls older than 10 years (4.8%). At the institutional level, increased rates of diagnostic imaging (ultrasound and/or CT) were associated with lower NARs for all age and gender subgroups other than children younger than 5 years, The NAR was 1.2% for boys older than 5 years without any diagnostic imaging.

CONCLUSIONS

The impact of diagnostic imaging on negative appendectomy rate varies by age and gender. Diagnostic imaging for boys older than 5 years with suspected appendicitis has no meaningful impact on NAR. Diagnostic strategies for possible appendicitis should incorporate the risk of negative appendectomy by age and gender.

The process of treating pediatric appendicitis

BACKGROUND

A large service and distant geographical area can make the process of diagnosing and treating appendicitis a challenge.

METHODS

Hospital records of children treated for appendicitis between 2007 and 2009 were retrospectively analyzed, including time from emergency (ER) to operating room (OR), diagnostic imaging (DI) utilization, preoperative antibiotic usage, operating time, length of stay (LOS), and perforation rate.

RESULTS

The perforation rate was 34%, with longer LOS. Transfer time to the children's hospital between ER inside and outside the city was not different. ER to OR time was significantly shorter for patients assessed at the children's hospital directly. Ultrasound remained the most used DI modality (55%). Preoperative antibiotics were only fully administered in 42% of the cases.

CONCLUSION

A clinical pathway for pediatric appendicitis may address the challenges of the process of pre-ER, ER to OR, and OR care to maintain an acceptable perforation rate.

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

OBJECTIVE

The purpose of this study was to evaluate the negative predictive value (NPV) of sonography in the diagnosis of acute appendicitis.

METHODS

Right lower quadrant sonograms of 193 patients (158 female and 35 male; age range, 3-20 years) with suspected acute appendicitis over a 1-year period were retrospectively reviewed. Sonographic findings were graded on a 5-point scale, ranging from a normal appendix identified (grade 1) to frankly acute appendicitis (grade 5). Sonographic findings were compared with subsequent computed tomographic (CT), surgical, and pathologic findings. The diagnostic accuracy of sonography was assessed considering surgical findings and clinical follow-up as reference standards.

RESULTS

Forty-nine patients (25.4%) had appendicitis on sonography, and 144 (74.6%) had negative sonographic findings. Computed tomographic scans were obtained in 51 patients (26.4%) within 4 days after sonography. These included 39 patients with negative and 12 with positive sonographic findings. Computed tomography changed the sonographic diagnosis in 10 patients: from negative to positive in 3 cases and positive to negative in 7. Forty-three patients (22.2%) underwent surgery. The surgical findings were positive for appendicitis in 37 (86%) of the 43 patients who had surgery. Patients with negative sonographic findings who, to our knowledge, did not have subsequent CT scans or surgery were considered to have negative findings for appendicitis. Seven patients with negative sonographic findings underwent surgery and had appendicitis; therefore, 137 of 144 patients with negative sonographic findings did not have appendicitis. On the basis of these numbers, the NPV was 95.1%.

CONCLUSIONS

Sonography has a high NPV and should be considered as a reasonable screening tool in the evaluation of acute appendicitis. Further imaging could be performed if clinical signs and symptoms worsen.

Noncontrast and contrast enhanced computed tomography for diagnosing acute appendicitis: A retrospective study for the usefulness

Abdominal computed tomography (CT) provides great benefits for the differential diagnosis in patients complaining of acute abdominal pain. However, the use of diagnostic X-rays is associated with the cumulative risk of cancer development. In order to determine the relative usefulness of noncontrast and enhanced CT with intravenous contrast material for diagnosing acute appendicitis, the retrospective analysis was performed using 247 patients (46 children and 201 adults) with clinically suspected appendicitis, who were admitted to our hospital from 2002 to 2006 and underwent noncontrast or combined noncontrast and enhanced CT examination. Of 185 patients who were diagnosed to have acute appendicitis with appendiceal thickening (167 cases) or normal-sized appendix (18 cases), 73 cases underwent noncontrast CT alone and these 73 cases could be retrospectively diagnosed to have appendicitis on noncontrast CT. On the other hand, 112 cases of these 185 patients underwent noncontrast CT followed by enhanced CT, and vermiform appendix was detected in 86 cases of them (86/112, 76.8%) on noncontrast CT. These 86 cases could be retrospectively diagnosed to have acute appendicitis on noncontrast CT, whereas enhanced CT was required to detect vermiform appendix and to obtain the final diagnosis of appendicitis in the remaining 26 cases (26/112, 23.2%). Enhanced CT was superior to noncontrast CT in diagnosing appendicitis in all age and any gender groups. We suggest that enhanced, but not noncontrast, CT should be primarily performed for diagnosing acute appendicitis in all patients to minimize the radiation exposure unless intravenous administration of contrast material is contraindicated.

Appendicitis in young children: imaging experience and clinical outcomes

OBJECTIVE

Our purpose was to evaluate the imaging characteristics and clinical outcomes of children less than 5 years old who underwent surgery for presumed appendicitis.

CONCLUSION

Appendicitis is not rare in young children and imaging findings reflect the high frequency of perforation in this population.

MR imaging evaluation of acute appendicitis in pregnancy

PURPOSE

To retrospectively assess the diagnostic performance of magnetic resonance (MR) imaging in pregnant patients suspected of having acute appendicitis.

MATERIALS AND METHODS

The study was approved by the committee on clinical investigations and was HIPAA compliant. The informed consent requirement was waived. MR images were obtained in 51 consecutive pregnant patients (mean age, 28.3 years) who were clinically suspected of having acute appendicitis. In this protocol for pregnant patients, MR imaging is performed when findings at ultrasonography (US) are inconclusive or additional information is needed. Four patients had appendicitis, which was confirmed at surgery in three patients and at follow-up computed tomography in one patient. Initial interpretations were used for patient care and to calculate diagnostic accuracy. The appendix was considered normal at MR imaging if its diameter was less than or equal to 6 mm or if it was filled with air, oral contrast material, or both. An enlarged fluid-filled appendix (>7 mm in diameter) was considered an abnormal finding. An appendix with a diameter of 6-7 mm was considered an inconclusive finding; in those cases, the presence of periappendiceal inflammation was used for the final diagnosis. Three radiologists retrospectively assessed the visualization of the appendix by using a 5-point scale. Statistical analysis was performed by using the median and Fisher exact tests and the Spearman correlation coefficient.

RESULTS

MR images were positive for appendicitis in four patients and inconclusive in three. In the three patients with inconclusive results, the appendix was not seen in two patients and was borderline enlarged (7 mm in diameter) in the third. The overall sensitivity, specificity, prevalence-adjusted positive and negative predictive values, and accuracy for MR imaging was 100%, 93.6%, 1.4%, 100%, and 94.0%, respectively.

CONCLUSION

MR imaging is an excellent modality for use in excluding acute appendicitis in pregnant women who present with acute abdominal pain and in whom a normal appendix is not visualized at US.

CT for suspected appendicitis in children: an analysis of diagnostic errors

BACKGROUND

Mistakes have been made by the use of CT in diagnosing children with suspected appendicitis. Although others have reported the frequency of diagnostic errors, we were unable to find any studies that addressed the specific situations in which diagnostic errors occurred in children with suspected appendicitis.

OBJECTIVE

To investigate the frequency and type of diagnostic errors resulting from CT of children with suspected appendicitis when compared to surgical and pathological diagnosis.

MATERIALS AND METHODS

We reviewed imaging, clinical and pathological data on 1,207 consecutive pediatric patients who underwent CT examination for suspected appendicitis. Imaging findings were categorized as false-positive, false-negative, or indeterminate. Errors were classified as interpretative, technical or unavoidable. Concordance between surgical and pathological findings was also evaluated.

RESULTS

The imaging findings of 34 patients (2.8%) were discrepant with the pathological examination or clinical follow-up. The errors in 23 cases were classified as interpretive (68%) and 11 as unavoidable (32%), and no errors were classified as technical. There were 23 false-positive errors (68%), 6 false-negative errors (18%), and 5 indeterminate imaging studies (15%). Isolated CT findings of an enlarged (greater than 6 mm) appendix, fat stranding, thickened bowel or non-visualization of the distal appendix were the most common false-positive CT findings. Of these 34 patients, 22 underwent appendectomy, with 10 (45%) having discordant surgical and pathological findings.

CONCLUSIONS

Isolated CT findings of an appendicolith, an enlarged appendix, or minimal fat stranding are not sufficient signs for the diagnosis of appendicitis. Pathological diagnosis rather than surgical findings should be used as the reference standard of true-positive imaging findings.