Abstract
Background
Non-contrast magnetic resonance imaging (MRI) and ultrasound studies in pediatric
patients with suspected appendicitis are often non-diagnostic. The primary objective
of this investigation was to determine if combining these non-diagnostic imaging results
with white blood cell (WBC) cutoffs improves their negative predictive values (NPVs).
Methods
A retrospective chart review was conducted including patients ≤18 years old with suspected
appendicitis who had MRI performed with or without a preceding ultrasound study in
a pediatric emergency department. Imaging results were sorted into 2 diagnostic and
5 non-diagnostic categories. NPVs were calculated for the non-diagnostic MRI and ultrasound
categories with and without combining them with WBC cutoffs of <10.0 and <7.5 × 109/L.
Results
Of the 612 patients with MRI studies included, 402 had ultrasound studies performed.
MRI with incomplete visualization of a normal appendix without secondary signs of
appendicitis had an NPV of 97.9% that changed to 98.1% and 98.2% when combined with
WBC cutoffs of <10.0 and <7.5, respectively. Ultrasound studies with incomplete visualization
of a normal appendix without secondary signs had an NPV of 85.3% that improved to
94.8% and 96.5% when combined with WBC cutoffs of <10.0 and <7.5, respectively.
Conclusions
In pediatric patients with suspected appendicitis, MRI studies with incomplete visualization
of a normal appendix without secondary signs have a high NPV that does not significantly
change with the use of these WBC cutoffs. In contrast, combining WBC cutoffs with
ultrasound studies with the same interpretation identifies low-risk groups.
Keywords
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Article Info
Publication History
Published online: December 18, 2018
Accepted:
December 17,
2018
Received:
October 29,
2018
Identification
Copyright
© 2018 Elsevier Inc. All rights reserved.
