Extra-appendiceal findings in pediatric abdominal CT for suspected appendicitis

Effect of focused protocol on reducing radiation dose for children who require computed tomography for suspected appendicitis

BACKGROUND

Despite efforts to incorporate ultrasound into the evaluation of children for appendicitis, computed tomography (CT) is often used to aid in its diagnosis. CT scans, however, expose children to a considerable amount of radiation. In 2017, our institution began using a height-based Focused CT protocol for children with suspected appendicitis in need of CT.

OBJECTIVE

To compare the radiation dose received by children with suspected appendicitis who underwent a Standard CT of the abdomen and pelvis (CTAP) with that of a Focused CT.

METHODS

We conducted a retrospective study of children <18 years who underwent a CT scan for suspected appendicitis (2014-2020). We included all patients whose indication for CT was "appendicitis" or "right lower quadrant pain" and excluded those whose CT scan record lacked a radiation dose report. The effective radiation dose delivered was calculated using the dose-length product from the dose report. We compared the effective dose of those who received a Standard CTAP to those who received a Focused CT. To account for differences in radiation dose over time and by CT scanner, analyses were adjusted for CT dose index volume (CTDI_vol) and size-specific dose estimate (SSDE) using quantile regression.

RESULTS

A total of 474 patients who underwent CT were included. Prior to CT, 362(76%) had received an ultrasound. In total, 309(65%) patients underwent a Standard CTAP and 165(35%) underwent a Focused CT. The appendix was identified in 259(84%) Standard CTAPs compared to 151(92%) Focused CTs (p = 0.02). Compared to the Standard CTAP, children who received a Focused CT were exposed to a significantly lower effective dose (relative difference: CTDI-adjusted -13%[95% CI:-21,-5]; SSDE-adjusted -14%[95% CI:-24,-3]).

CONCLUSIONS

Our height-based Focused CT protocol reduces radiation for children undergoing CT evaluation for suspected appendicitis without sacrificing diagnostic accuracy. Further study is needed to validate these findings at other institutions.

ACR Appropriateness Criteria® Suspected Appendicitis-Child

Acute appendicitis represents the most common abdominal surgical urgency/emergency in children. Imaging remains a central tool in the diagnosis of acute appendicitis and has been shown to facilitate management and decrease the rate of negative appendectomies. The initial consideration for imaging in a child with suspected acute appendicitis is based on clinical assessment, which can be facilitated with published scoring systems. The level of clinical risk (low, intermediate, high) and the clinical scenario (suspicion for complication) define the need for imaging and the optimal imaging modality. In some situations, no imaging is required, while in others ultrasound, CT, or MRI may be appropriate. This review frames the presentation of suspected acute appendicitis in terms of the clinical risk and also discusses the unique situations of the equivocal or nondiagnostic initial ultrasound examination and suspected appendicitis with suspicion for complication (eg, bowel obstruction). The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Focused CT for the evaluation of suspected appendicitis

PURPOSE

To determine the diagnostic accuracy of focused appendiceal CT as a feasible alternative to the standard CT of the abdomen and pelvis (CT-AP) in patients with suspected acute appendicitis.

METHODS

Retrospective review of 200 adults with suspected acute appendicitis between January and October 2016 were included in this study. Each patient underwent CT-AP with oral and intravenous (IV) contrast. A subset of axial images starting at the top of L4 vertebral body to the roof of the acetabula were obtained from each study which served as the focused appendiceal CT. After review of the focused CTs, the non-focused CT-AP scans were reviewed, each patient acting as their own control. Images were assessed for ability to identify the appendix, assess for appendicitis, or identify alternative diagnoses that could account for the presenting symptoms.

RESULTS

Of 200 cases, the appendix was visualized in the focused CT in 191 patients. In nine studies, the appendix was not visualized in focused or standard CT-AP. Using focused CT, 42 cases were positive for acute appendicitis. This result was identical when reviewing standard CT-AP. Alternative diagnoses were present in 38 patients. Using focused CT, 14 of these were not fully covered but the readers were able to make the diagnoses confidently on the focused CTs. Only one patient had acute non-appendiceal pathology mostly outside of the field of view.

CONCLUSIONS

Focused appendiceal CT with IV and oral contrast in the setting of clinically suspected appendicitis is a suitable alternative to conventional CT-AP.

Incidental Findings on Pediatric Abdominal Computed Tomography At A Pediatric Trauma Center

BACKGROUND

The increasing availability and use of computed tomography (CT) in pediatric abdominal trauma has increased the detection of incidental findings. While some of these findings are benign, others may require further evaluation for possible clinical importance.

OBJECTIVES

This study aimed to identify the frequency and type of incidental findings and their need for follow-up on abdominal CT in patients at a pediatric trauma center.

METHODS

This was a retrospective, observational study on trauma patients ≤21 years of age who presented to the emergency department between January 1, 2004 and July 31, 2016 and underwent CT scans of the abdomen and pelvis. Findings were classified as benign anatomic variants, benign pathologic lesions, and pathologic lesions requiring additional work-up.

RESULTS

There were 1073 patients included in the study population, with a mean age of 15.5 years; 707 (66%) were males. A total of 418 incidental findings were identified in 345 patients. Of these, 290 (69%) were benign and 60 (14%) were likely benign pathologic that required possible outpatient monitoring. Of those requiring additional evaluation, 5 (1%) patients warranted further evaluation before discharge.

CONCLUSIONS

Nearly one-third of patients had at least one radiographic finding unrelated to their injury. Of these, more than two-thirds did not require additional evaluation, but nearly one-third of patients required some form of further work-up.

"Incidentalomas" on abdominal and pelvic CT in emergency radiology: literature review and current management recommendations

The purpose of this article is to familiarize radiologists and clinicians with a subset of common and uncommon incidental findings on abdominal and pelvic computed tomography examinations, including hepatic, splenic, renal, adrenal, pancreatic, aortic/iliac arterial, gynecological, and a few other miscellaneous findings, with an emphasis on "incidentalomas" discovered in the emergency setting. In addition, we will review the complex problem of diagnosing such entities, and provide current management recommendations. Representative case examples, which we have encountered in our clinical practices, will be demonstrated.

Alternative diagnoses at paediatric appendicitis MRI

As the utilization of MRI in the assessment for paediatric appendicitis increases in clinical practice, it is important to recognize alternative diagnoses as the cause of abdominal pain. The purpose of this review is to share our institution's experience using MRI in the evaluation of 510 paediatric patients presenting with suspected appendicitis over a 30 month interval (July 2011 to December 2013). An alternative diagnosis was documented in 98/510 (19.2%) patients; adnexal pathology (6.3%, n = 32), enteritis-colitis (6.3%, n = 32), and mesenteric adenitis (2.2%, n = 11) comprised the majority of cases. These common entities and other less frequent illustrative cases obtained during our overall institutional experience with MRI for suspected appendicitis are reviewed.

Clinical mimics of acute appendicitis: Is there any role of imaging?

Acute appendicitis (AA) is a common surgical emergency. Accurate and timely diagnosis of AA is essential for successful outcome. Imaging plays an important role in the diagnosis, exclusion of AA as well as diagnosing alternative clinical conditions which can closely simulate AA. A correct alterative diagnosis may obviate the need of unnecessary appendectomy or may even change the treatment regime altogether. This pictorial essay illustrates various clinical conditions which mimicked AA clinically during our day to day practice.