Abdominal Radiology

, Volume 44, Issue 1, pp 22–30 | Cite as

Conical ultrashort echo time (UTE) MRI in the evaluation of pediatric acute appendicitis

  • Albert T. Roh
  • Zhibo Xiao
  • Joseph Y. Cheng
  • Shreyas S. Vasanawala
  • Andreas M. LoeningEmail author



Magnetic resonance imaging (MRI) sequences with conical k-space trajectories are able to decrease motion artifacts while achieving ultrashort echo times (UTE). We assessed the performance of free-breathing conical UTE MRI in the evaluation of the pediatric pelvis for suspected appendicitis.


Our retrospective review of 84 pediatric patients who underwent MRI for suspected appendicitis compared three contrast-enhanced sequences: free-breathing conical UTE, breath-hold three-dimensional (3D) spoiled gradient echo (BH-SPGR), and free-breathing high-resolution 3D SPGR (FB-SPGR). Two radiologists performed blinded and independent evaluations of each sequence for image quality (four point scale), anatomic delineation (four point scale), and diagnostic confidence (five point scale). Subsequently, the three sequences were directly compared for overall image quality (− 3 to + 3 scale). Scores were compared using Kruskal–Wallis and Wilcoxon signed-rank tests.


UTE demonstrated significantly better perceived signal-to-noise ratio (SNR) and fewer artifacts than BH-SPGR and FB-SPGR (means of 3.6 and 3.4, 3.4 and 3.2, 3.1 and 2.7, respectively; p < 0.0006). BH-SPGR and FB-SPGR demonstrated significantly better contrast than UTE (means of 3.6, 3.4, and 3.2, respectively; p < 0.03). In the remaining categories, UTE performed significantly better than FB-SPGR (p < 0.00001), while there was no statistical difference between UTE and BH-SPGR. Direct paired comparisons of overall image quality demonstrated the readers significantly preferred UTE over both BH-SPGR (mean + 0.5, p < 0.00001) and FB-SPGR (mean + 1.2, p < 0.00001).


In the evaluation of suspected appendicitis, free-breathing conical UTE MRI performed better in the assessed metrics than FB-SPGR. When compared to BH-SPGR, UTE demonstrated superior perceived SNR and fewer artifacts.


Ultrashort echo time Non-Cartesian Pediatric Appendicitis Pelvis 


Compliance with ethical standards


This study was funded by NIBIB R01EB009690.

Conflict of interest

Albert T. Roh, Zhibo Xiao, Joseph Y. Cheng, and Andreas M. Loening declare that they have no conflict of interest. Shreyas S. Vasanawala has received grant support from NIBIB R09EB009690.

Ethical approval

All procedures performed in studies involving human participants were in accordance with the ethical standards of the Institutional Research Committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.


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Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  • Albert T. Roh
    • 1
  • Zhibo Xiao
    • 2
  • Joseph Y. Cheng
    • 1
  • Shreyas S. Vasanawala
    • 1
  • Andreas M. Loening
    • 1
    Email author
  1. 1.RadiologyStanford UniversityStanfordUSA
  2. 2.RadiologyFirst Affiliated HospitalChongqingChina

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