Diagnostic utility of intravenous contrast for MR imaging in pediatric appendicitis

• Published in: Pediatric radiology 2017-04, Vol.47 (4), p.398-403
• Main Authors: Lyons, Gray R., Renjen, Pooja, Askin, Gulce, Giambrone, Ashley E., Beneck, Debra, Kovanlikaya, Arzu
• Format: Article
• Language: English
• Subjects: Adolescent; Appendicitis - diagnostic imaging; Appendix - diagnostic imaging; Child; Child, Preschool; Contrast Media - administration & dosage; Humans; Image Enhancement - methods; Imaging; Magnetic Resonance Imaging - methods; Medicine; Medicine & Public Health; Neuroradiology; Nuclear Medicine; Oncology; Original Article; Pediatrics; Radiology; Reproducibility of Results; Retrospective Studies; Sensitivity and Specificity; Ultrasound; Young Adult
• ISSN: 0301-0449; 1432-1998
• DOI: 10.1007/s00247-016-3775-8

Background Magnetic resonance imaging (MRI) is increasingly employed as a diagnostic modality for suspected appendicitis in children. However, there is uncertainty as to which MRI sequences are sufficient for safe, timely and accurate diagnosis. Several recent studies have described different MRI protocols, including exams both with and without the use of intravenous contrast. Objective We hypothesized that intravenous contrast may be useful in some patients but could be safely omitted in others. Materials and methods All MRI examinations ( n =112) performed at our institution for evaluating appendicitis in children were retrospectively reevaluated. Exams were reread by pediatric radiologists under three conditions: With postcontrast images, Without postcontrast images, and Without/With – selective use of postcontrast sequences only when needed for diagnostic certainty. Samples were scored as positive, negative or equivocal for appendicitis. Findings were compared to pathological or clinical follow-up in the medical record. Results Without the use of intravenous contrast yielded more equivocal results (12.4%) compared to With contrast (3.4%). By selectively using postcontrast sequences, the Without/With group yielded fewer equivocal results (1.1%) compared to Without while also reducing contrast use 79.8% compared to the With contrast group. No significant differences in conditional sensitivity or conditional specificity were detected among the three groups. Conclusion MRI diagnosis of acute appendicitis can be performed without contrast for most patients; injection of contrast can be reserved for only those patients with equivocal non-contrast imaging.