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Utility of applying white blood cell cutoffs to non-diagnostic MRI and ultrasound studies for suspected pediatric appendicitis

Published:December 18, 2018DOI:https://doi.org/10.1016/j.ajem.2018.12.029

      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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      References

        • Lipsett S.C.
        • Bachur R.G.
        Current approach to the diagnosis and emergency department management of appendicitis in children.
        Pediatr Emerg Care. 2017; 33: 198-203
        • Benabbas R.
        • Hanna M.
        • Shah J.
        • Sinert R.
        Diagnostic accuracy of history, physical examination, laboratory tests, and point-of-care ultrasound for pediatric acute appendicitis in the emergency department: a systematic review and meta-analysis.
        Acad Emerg Med. 2017; 24: 523-551
        • Brenner D.J.
        • Hall E.J.
        Computed tomography – an increasing source of radiation exposure.
        N. Engl. J. Med. 2007; 357: 2277-2284
        • Pearce M.S.
        • Salotti J.A.
        • Little M.P.
        • et al.
        Radiation exposure from CT scans in childhood and subsequent risk of leukaemia and brain tumours: a retrospective cohort study.
        Lancet. 2012; 380: 499-505
        • Smith M.P.
        • Katz D.S.
        • Lalani T.
        • et al.
        ACR appropriateness criteria® right lower quadrant pain–suspected appendicitis.
        Ultrasound Q. 2015; 31: 85-91
        • Cohen B.
        • Bowling J.
        • Midulla P.
        • et al.
        The non-diagnostic ultrasound in appendicitis: is a non-visualized appendix the same as a negative study?.
        J Pediatr Surg. 2015; 50: 923-927
        • Anandalwar S.P.
        • Callahan M.J.
        • Bachur R.G.
        • et al.
        Use of white blood cell count and polymorphonuclear leukocyte differential to improve the predictive value of ultrasound for suspected appendicitis in children.
        J Am Coll Surg. 2015; 220: 1010-1017
        • Moore M.M.
        • Gustas C.N.
        • Choudhary A.K.
        • et al.
        MRI for clinically suspected pediatric appendicitis: an implemented program.
        Pediatr Radiol. 2012; 42: 1056-1063
        • Koning J.L.
        • Naheedy J.H.
        • Kruk P.G.
        Does abdominal pain duration affect the accuracy of first-line MRI for pediatric appendicitis?.
        Abdom Imaging. 2015; 40: 352-359
        • Petkovska I.
        • Diego M.R.
        • Covington M.F.
        • et al.
        Accuracy of unenhanced MR imaging in the detection of acute appendicitis: single-institution clinical performance review.
        Radiology. 2016; 279: 451-460
        • Imler D.
        • Keller C.
        • Sivasankar S.
        • et al.
        Magnetic resonance imaging versus ultrasound as the initial imaging modality for pediatric and young adult patients with suspected appendicitis.
        Acad Emerg Med. 2017; 24: 569-577
        • Leeuwenburgh M.M.
        • Stockmann H.B.
        • Bouma W.H.
        • et al.
        A simple clinical decision rule to rule out appendicitis in patients with nondiagnostic ultrasound results.
        Acad Emerg Med. 2014; 21: 487-496
        • Nishizawa T.
        • Maeda S.
        • Goldman R.D.
        • Hayashi H.
        Predicting need for additional CT scan in children with a non-diagnostic ultrasound for appendicitis in the emergency department.
        Am J Emerg Med. 2018; 36: 49-55
        • Kulaylat A.N.
        • Moore M.M.
        • Engbrecht B.W.
        • et al.
        An implemented MRI program to eliminate radiation from the evaluation of pediatric appendicitis.
        J Pediatr Surg. 2015; 50: 1359-1363
        • Kearl Y.L.
        • Claudius I.
        • Behar S.
        • et al.
        Accuracy of magnetic resonance imaging and ultrasound for appendicitis in diagnostic and nondiagnostic studies.
        Acad Emerg Med. 2016; 23: 179-185
        • Samuel M.
        Pediatric appendicitis score.
        J Pediatr Surg. 2002; 37: 877-881
        • Bundy D.G.
        • Byerley J.S.
        • Liles E.A.
        • Perrin E.M.
        • Katznelson J.
        • Rice H.E.
        Does this child have appendicitis?.
        JAMA. 2007; 298: 438-451
        • Fedko M.
        • Bellamkonda V.R.
        • Bellolio M.F.
        • et al.
        Ultrasound evaluation of appendicitis: the importance of the 3 × 2 table for outcome reporting.
        Am J Emerg Med. 2014; 32: 345-348
        • Schuetz G.M.
        • Schlattmann P.
        • Dewey M.
        Use of 3 × 2 tables with an intention to diagnose approach to assess clinical performance of diagnostic tests: meta-analytical evaluation of coronary CT angiography studies.
        BMJ. 2012; 345: e6717
        • Garcia K.
        • Hernanz-Schulman M.
        • Bennett D.L.
        • Morrow S.E.
        • Yu C.
        • Kan J.H.
        Suspected appendicitis in children: diagnostic importance of normal abdominopelvic CT findings with nonvisualized appendix.
        Radiology. 2009; 250: 531-537
        • Rosines L.A.
        • Chow D.S.
        • Lampl B.S.
        • et al.
        Value of gadolinium-enhanced MRI in detection of acute appendicitis in children and adolescents.
        AJR Am J Roentgenol. 2014; 203: W543-W548
        • Duke E.
        • Kalb B.
        • Arif-Tiwari H.
        • et al.
        A systematic review and meta-analysis of diagnostic performance of MRI for evaluation of acute appendicitis.
        AJR Am J Roentgenol. 2016; 206: 508-517
        • Lyons G.R.
        • Renjen P.
        • Askin G.
        • Giambrone A.E.
        • Beneck D.
        • Kovanlikaya A.
        Diagnostic utility of intravenous contrast for MR imaging in pediatric appendicitis.
        Pediatr Radiol. 2017; 47: 398-403
        • Moore M.M.
        • Kulaylat A.N.
        • Hollenbeak C.S.
        • Engbrecht B.W.
        • Dillman J.R.
        • Methratta S.T.
        Magnetic resonance imaging in pediatric appendicitis: a systematic review.
        Pediatr Radiol. 2016; 46: 928-939
        • Moore M.M.
        • Kulaylat A.N.
        • Brian J.M.
        • et al.
        Alternative diagnoses at paediatric appendicitis MRI.
        Clin Radiol. 2015; 70: 881-889
        • Aspelund G.
        • Fingeret A.
        • Gross E.
        • et al.
        Ultrasonography/MRI versus CT for diagnosing appendicitis.
        Pediatrics. 2014; 133: 586-593