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MR Safe Abdominal Pressure Sensor System for Compression Or Breath-Hold Motion Management with Visual Biofeedback for Liver SBRT

B Lewis*, R Cadrain , S Kim , T Kim , Virginia Commonwealth University, Richmond, VA


(Sunday, 7/29/2018) 5:05 PM - 6:00 PM

Room: Room 202

Purpose: To introduce a novel abdominal pressure sensor system with visual biofeedback in MR for compressed or breath-hold liver SBRT.

Methods: The concept of real-time respiratory motion management with biofeedback was implemented by modifying a commercially available pressure sensor belt system. The belt system was modified by removal of the metal-rubber air pump, metallic pressure gauge, and metal facets, creating a sealed system with minimal air loss. The belt was connected to an electronic pressure sensor placed at the periphery of the MR suite which sent the real-time pressure signal to the subject using an in-room screen, and mirrored glasses, through a commercial software (LoggerPro). Two MR imaging sessions separated by one week were performed with two investigators. Investigators were imaged under three scenarios: free breathing (FB), maintaining their respiratory signal within a large compression window, and within a small compression window on the visual guidance screen. A CINE MR acquisition over 30s and a diffusion weighted imaging (DWI) volume with two b-values were acquired for each scenario. In addition, 5 healthy volunteers participated in two MR imaging sessions separated by one week with the proposed compression system. In the study, the system had been demonstrated for breath-hold control. A CINE MR acquisition and a diffusion weighted imaging (DWI) volume with two b-values were acquired.

Results: In the compression study, peak-to-peak motion of the liver dome was reduced from a mean of 30.55±7.83mm for FB to 11.5±3.67mm and 5.58±0.85mm for large and small bounding windows respectively. Further, b-value images of the same slice had decreased motion between acquisitions.

Conclusion: The respiratory motion management and biofeedback system developed for this work can greatly reduce peak-to-peak motion of the liver in the compression study and reduce motion error during DWI acquisition.

Funding Support, Disclosures, and Conflict of Interest: Supported by Institutional Research Grant IRG-14-192-40 from the American Cancer Society


Not Applicable / None Entered.


TH- RT Interfraction motion management : setup errors, immobilization, localization

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