Ryne Didier MD, Presenter: Nothing to Disclose

Bryan Robert Foster MD, Abstract Co-Author: Nothing to Disclose

Fergus V. Coakley MD, Abstract Co-Author: Nothing to Disclose

Sanjay Krishnaswami MD, Abstract Co-Author: Nothing to Disclose

David Spiro MD, Abstract Co-Author: Nothing to Disclose

Katharine Lee Hopkins MD, Abstract Co-Author: Nothing to Disclose

Historically, limited availability, high cost and motion artifact prevented the use of MRI in the evaluation of acute pediatric appendicitis. However, recent developments have allowed utilization even in non-sedated pediatric patients. Concerns regarding ionizing radiation employed by CT have encouraged use of alternative imaging modalities. The purpose of this study was to evaluate the performance characteristics of MRI without contrast or sedation in the diagnosis of pediatric appendicitis.

Patients <18 years of age with suspected acute appendicitis who underwent clinically indicated US were eligible. No contrast or sedation was administered. After a scout sequence was performed, five sequences were obtained including diffusion weighted imaging (DWI). The duration from the scout sequence to the presence of images in PACS (overestimate of total scan time) was recorded.  Previously established diagnostic criteria for acute appendicitis were used to interpret the MR by two blinded reviewers.  In the case of discrepancy, the official report issued by a non-binded radiologist was used as a "tie-breaker." Results were compared with US results, clinical outcome, operative reports, and surgical pathology results, if available.  

To date, 36 examinations have been performed, 21 females (58%) and 15 males (42%). Mean age was 11.05 years (3.16-17.9). The examination was tolerated by all participants.  The two reviewers demonstrated good agreement (kappa = 0.667). 5 discrepancies were identified; two were resolved by the "tie-breaker."  The average time from scout to PACS was 27.44 minutes.  The protocol yielded 92.9% sensitivity and 90.9% specificity for acute appendicitis with a diagnostic accuracy of 89.7%. Two false positives and one false negative were reported which were concordant with the ultrasound results. Additionally, these three studies produced discrepant results among the two reviewers. All three patients ultimately underwent appendectomy based on clinical data.

Preliminary implementation of a rapid MRI protocol without contrast or sedation in the evaluation of pediatric appendicitis yielded promising performance characteristics. Although further investigation is warranted, this imaging protocol may provide clinicians with an alternative to CT.

Rapid MRI without contrast or sedation is a promising alternative to CT in the evaluation of pediatric appendicitis.

Didier, R, Foster, B, Coakley, F, Krishnaswami, S, Spiro, D, Hopkins, K, Rapid MRI in Pediatric Appendicitis without Contrast or Sedation.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14016300.html