An interactive videogame designed to improve respiratory navigator efficiency in children undergoing cardiovascular magnetic resonance.
Advanced cardiovascular magnetic resonance (CMR) acquisitions often require long scan durations that necessitate respiratory navigator gating. The tradeoff of navigator gating is reduced scan efficiency, particularly when the patient's breathing patterns are inconsistent, as is commonly seen in children. We hypothesized that engaging pediatric participants with a navigator-controlled videogame to help control breathing patterns would improve navigator efficiency and maintain image quality.



We developed custom software that processed the Siemens respiratory navigator image in real-time during CMR and represented diaphragm position using a cartoon avatar, which was projected to the participant in the scanner as visual feedback. The game incentivized children to breathe such that the avatar was positioned within the navigator acceptance window (±3 mm) throughout image acquisition. Using a 3T Siemens Tim Trio, 50 children (Age: 14 ± 3 years, 48 % female) with no significant past medical history underwent a respiratory navigator-gated 2D spiral cine displacement encoding with stimulated echoes (DENSE) CMR acquisition first with no feedback (NF) and then with the feedback game (FG). Thirty of the 50 children were randomized to undergo extensive off-scanner training with the FG using a MRI simulator, or no off-scanner training. Navigator efficiency, signal-to-noise ratio (SNR), and global left-ventricular strains were determined for each participant and compared.



Using the FG improved average navigator efficiency from 33 ± 15 to 58 ± 13 % (p < 0.001) and improved SNR by 5 % (p = 0.01) compared to acquisitions with NF. There was no difference in navigator efficiency (p = 0.90) or SNR (p = 0.77) between untrained and trained participants for FG acquisitions. Circumferential and radial strains derived from FG acquisitions were slightly reduced compared to NF acquisitions (-16 ± 2 % vs -17 ± 2 %, p < 0.001; 40 ± 10 % vs 44 ± 11 %, p = 0.005, respectively). There were no differences in longitudinal strain (p = 0.38).



Use of a respiratory navigator feedback game during navigator-gated CMR improved navigator efficiency in children from 33 to 58 %. This improved efficiency was associated with a 5 % increase in SNR for spiral cine DENSE. Extensive off-scanner training was not required to achieve the improvement in navigator efficiency.
Department of Electrical Engineering, University of Kentucky, Lexington, KY, USA.|Department of Pediatrics, University of Kentucky, Lexington, KY, USA.
Sean M
SM
Hamlet
Department of Pediatrics, University of Kentucky, Lexington, KY, USA.|Institute for Advanced Application, Geisinger Health System, Danville, PA, USA.
Christopher M
CM
Haggerty
Department of Pediatrics, University of Kentucky, Lexington, KY, USA.|Institute for Advanced Application, Geisinger Health System, Danville, PA, USA.
Jonathan D
JD
Suever
Department of Pediatrics, University of Kentucky, Lexington, KY, USA.|Department of Biomedical Engineering, University of Kentucky, Lexington, KY, USA.
Gregory J
GJ
Wehner
Department of Pediatrics, University of Kentucky, Lexington, KY, USA.
Jonathan D
JD
Grabau
Department of Pediatrics, University of Kentucky, Lexington, KY, USA.
Kristin N
KN
Andres
Department of Biomedical Engineering, University of Kentucky, Lexington, KY, USA.|Department of Physiology, University of Kentucky, Lexington, KY, USA.
Moriel H
MH
Vandsburger
Department of Biomedical Engineering, University of Kentucky, Lexington, KY, USA.
David K
DK
Powell
Department of Medicine, University of Kentucky, Lexington, KY, USA.
Vincent L
VL
Sorrell
Department of Pediatrics, University of Kentucky, Lexington, KY, USA. bkf@gatech.edu.|Institute for Advanced Application, Geisinger Health System, Danville, PA, USA. bkf@gatech.edu.|Department of Biomedical Engineering, University of Kentucky, Lexington, KY, USA. bkf@gatech.edu.|Department of Physiology, University of Kentucky, Lexington, KY, USA. bkf@gatech.edu.|Department of Medicine, University of Kentucky, Lexington, KY, USA. bkf@gatech.edu.
Brandon K
BK
Fornwalt
D000293:Adolescent; D000367:Age Factors; D001696:Biomechanical Phenomena; D002648:Child; D003964:Diaphragm / Q000033:anatomy & histology / Q000502:physiology*; D030141:Feedback, Psychological; D005260:Female; D006339:Heart Rate; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007629:Kentucky; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D015656:Respiratory Mechanics; D012984:Software; D013314:Stress, Mechanical; D013997:Time Factors; D016277:Ventricular Function, Left; D018910:Video Games
Cardiovascular magnetic resonance; Image quality; Navigator efficiency; Pediatrics; Respiratory navigator