First-Line Diagnostic Evaluation with MRI of Children Suspected of Having Acute Appendicitis

Abstract

Background: Advances in abdominal MRI have enabled rapid, free-breathing imaging without the need for intravenous or oral contrast material. The use of MRI as the primary imaging modality for suspected appendicitis has not been previously studied.Purpose: To determine the diagnostic performance of MRI as the initial imaging modality in children suspected of having acute appendicitis. Materials and Methods:The study included consecutive patients 18 years of age and younger presenting with acute abdominal pain at a tertiary care institution from January 2013 through June 2016 who subsequently underwent an unenhanced MRI examination as the primary diagnostic imaging modality. Electronic medical records and radiology reports were retrospectively evaluated for the feasibility and diagnostic performance of MRI, with surgical pathology and follow-up electronic records as reference standards. Statistical analyses were performed by using simple binomial proportions to quantify sensitivity, specificity, and accuracy, and exact 95% confidence intervals (CIs) were obtained.Results: After exclusions, 402 patients (median age: 13 years; interquartile range [IQR], 9-15 years; 235 female patients; 167 male patients) were included. Sedation for MRI was required in 13 of 402 patients (3.2%; 95% CI: 1.7%, 5.5%). The appendix was visualized in 349 of 402 patients (86.8%; 95% CI: 83.1%, 90%); for the remaining patients, a diagnosis was provided on the basis of secondary signs of appendicitis. The sensitivity, specificity, and accuracy of MRI as the primary diagnostic imaging modality for the evaluation of acute appendicitis were 97.9% (95 of 97; 95% CI: 92.8%, 99.8%), 99% (302 of 305; 95% CI: 97.2%, 99.8%), and 98.8% (397 of 402; 97.1%, 99.6%), respectively. Among patients with negative findings for appendicitis at MRI, an alternate diagnosis was provided in 113 of 304 patients (37.2%; 95% CI: 31.7%, 42.9%). Conclusion:When performed as the initial imaging modality in children suspected of having acute appendicitis, MRI examinations had high diagnostic performance for the diagnosis of acute appendicitis and in providing alternative diagnoses.

Performance of overnight on-call radiology residents in interpreting unenhanced abdominopelvic magnetic resonance imaging studies performed for pediatric right lower quadrant abdominal pain

“…In general, MRI examinations are performed according to a standardized protocol and completed by the technologist without real-time radiologist supervision. Further detail regarding workflow in our department, including average times from MRI order to image acquisition and interpretation, can be found in a recently published study [ 11 ].…”

“…Exclusion criteria included: (1) age 18 years or older (in order to better adhere to the commonly held definition of a pediatric cohort), (2) MRI following either a CT or US examination, (3) incomplete MRI, (4) previous history of appendectomy and (5) lost to follow-up (defined by a lack of subsequent visits recorded in the electronic medical record). This cohort of patients has been examined in a previous study [ 11 ]; additional exclusion criteria were applied in the current study, such that the 377 patients included in the current study overlap with the 402 patients in the previous study. The additional exclusion criteria for the current study were patients whose reports were rendered exclusively by an attending radiologist or generated by a first-year resident under direct attending supervision.…”

“…However, advances in MRI protocols have allowed for rapid non-contrast examinations that maintain a high degree of sensitivity/specificity [ 9 , 10 ]. A recent study demonstrated the efficacy of MRI when employed as a first-line modality in pediatric patients suspected of having acute appendicitis [ 11 ].…”

How I do it – CT-Protokolle beim akuten Abdomen

“…Aufgrund der allgemein etwas schlechteren Verfügbarkeit und längeren Untersuchungsdauer ist diese bei den zum Teil klinisch stark beeinträchtigten Patienten in der Regel speziellen Situation vorbehalten (z. B. der Untersuchung von Schwangeren oder Kindern) [8]. Die CT ist die Bildgebung der Wahl und das Arbeitspferd bei der weiteren Abklärung von Patienten mit einem akuten Abdomen.…”

Falling through the worm hole: an exploration of the imaging workup of the vermiform appendix in the pediatric population

“…Another study published earlier this year explored the utility of using MR as a first line imaging modality in children with suspected appendicitis. 88 Given its lack of ionizing radiation, feasibility without i.v. contrast, and relative operator independence (as well as its exquisite soft tissue contrast to aid in the detection of other intra-abdominal pathology), MRI may very well supplant CT and ultrasound as the first line imaging choice for suspected appendicitis in the future.…”