Contrast-Enhanced Focused Assessment with Sonography for Trauma (cFAST) Far Forward: Contrast Visualization Methods Testing of Six Field-Portable and Handheld Ultrasound Systems.

Abstract

Introduction: The focused assessment with sonography in trauma (FAST) is the most important ultrasound exam in the operational environment, yet its sensitivity for diagnosis of solid organ injury is limited. Contrast-enhanced FAST (cFAST) augments the diagnostic power of the FAST exam of parenchymal and vascular injuries, and it rivals CT. Studies on cFAST have not used handheld ultrasound systems found in the combat environment.

Methods: As part of a methodsdesign process for a cFAST study, the authors tested six hand-held and portable ultrasound systems for their ability to visualize contrast enhancement: Philips Lumify, Butterfly IQ3, GE Vscan Air, Fujifilm Sonosite Edge II, Fujifilm Sonosite M-Turbo, and GE Venue (cart-based comparator). None had dedicated "contrast" settings. Device settings were adjusted to minimize gain and maintain a mechanical index below .3. Three standardized patients received .02mL to .11mL intravenous boluses of perflutren (Definity) followed by a 10mL saline flush. The right upper quadrant was scanned to assess contrast visualization in the kidney.

Results: Contrast enhancement was visualized on only one handheld device (GE Vscan Air) and the GE Venue (cart-based comparator). No enhancement was seen with the others.

Conclusions: Most handheld and portable ultrasound systems currently used in deployed medical settings failed to visualize contrast. While the GE Vscan Air shows promise, further investigation is necessary to determine whether system modifications, software upgrades, or dosing adjustments can enable cFAST capability in the far-forward environment. Reliable handheld-based cFAST methods will advance research and implementation of this technology in military trauma care.