Page 76 - JSOM Spring 2026

Even where CT is available at a Role 3 or Role 4 Military The contrast agent used was perflutren (Definity, Lantheus,
Treatment Facility (MTF), cFAST has the added benefits of Bedford, MA,.), which is on the formulary of the MTF where
sparing patients ionizing radiation and iodinated contrast. For the authors are stationed. The authors received no financial
these reasons, Menichini et al. recommend cFAST as the “first support, funding, or sponsorship from Lantheus, the manu-
line approach in children with [a] history of minor blunt ab- facturer of Definity, nor did any representative of Lantheus
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dominal trauma,” a salient point in the context of the num- have any input into the design of the methods testing or the
ber of children treated by military medical providers in the preparation of this manuscript.
deployed setting. 18–20 Moreover, guidance issued by the Euro-
pean Federation of Societies for Ultrasound in Medicine and Perflutren is octafluoropropane gas encapsulated in a lipid
Biology recommends that contrast-enhanced ultrasound be shell, which forms microbubbles between 1.1 and 3.3 microns
used in “hemodynamically stable patients with isolated blunt in diameter—smaller than a red blood cell, but large enough to
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moderate-energy abdominal trauma to evaluate solid organ remain intravascular. Definity must be refrigerated, but after

injury as an alternative to CT.” 21 removal from the refrigerator, it can be stored at room tem-
perature and used up to 72 hours after being removed from
As such, cFAST has the transformative potential to improve refrigeration, factors that may affect its suitability for opera-
casualty care and optimize allocation of resources far forward. tional use.
To date, studies on cFAST have not used handheld or portable
ultrasound systems most likely to be found in the deployed en- Prior to injection, perflutren must be activated with a device
vironment from the point-of-injury to a Role 2. As part of our called VialMix. The device weighs just over one pound, and its
process for designing such a study, the authors tested methods approximate dimensions are 11×5×3 inches. It can be powered
for performing cFAST with ultrasound systems most likely to with rechargeable batteries. The VialMix activates the contrast
be found in United States military medical units doctrinally by agitating it for 45 seconds; the contrast does not function
assigned forward medical care. without activation. Once activated, however, the contrast re-
mains activated for 48 hours. As with the need for refrigera-
tion, the requirement for the extra equipment to activate the
Methods
contrast is a factor that impacts the suitability of Definity for
Six ultrasound systems were included in the methods testing: use in austere, combat environments.
Philips Lumify (Philips Healthcare, Best, The Netherlands),
Butterfly IQ3 (Butterfly Network, Inc., Guilford, CT), GE Microbubbles are highly echogenic because their gas cores
Vscan Air (General Electric, Boston, MA), Fuji Sonosite Edge have lower acoustic impedance than the surrounding blood,
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II (Fuji Sonosite, Bothwell, WA), Fuji Sonosite M-Turbo (Fuji resulting in significant reflection of sound waves. Their du-
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Sonosite, Bothwell, WA), and GE Venue (General Electric, ration of action is approximately seven minutes, after which
Boston, MA). The first five of these systems are likely to be the lipid shells are metabolized in the liver, and the octafluoro-
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found in combat environments. These handheld or portable propane gas is exhaled.
ultrasound systems are typically purchased by units or in-
dividual medical providers, although the Army has initiated Fasting or pre-administration labs are not required for perfl-
the process of integrating handheld ultrasound systems into utren, as it is not excreted by the kidneys, and renal failure is
the modified table of organization and equipment for use not a contraindication. Indeed, perflutren has only two con-
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forward of a Role 2 through an acquisition program called traindications: (1) cardiac shunts, or (2) known or suspected
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Ultrasound Field Portable. The final system in our methods hypersensitivity to perflutren (including its components, which
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testing, the GE Venue, was included to provide a compari- include polyethylene glycol). Serious adverse reactions are
son with a cart-based system featuring more powerful image rare, occurring at 1.1 per 10,000; this rate is lower than the
processing software than is typically available in the austere adverse reaction rate to CT contrast. 23,24
setting of deployment.
Three of the authors (MA, CAM, and DK) consented to serve
To the extent possible, the settings on all devices were adjusted as standardized patients for the methods testing. Each had an
to reduce gain, facilitate contrast visualization, and lower the IV placed with a 20-gauge needle in the right antecubital fossa.
mechanical index (MI) below 0.3. In general, a low MI de- Each exam began with a preliminary non-contrasted scan of
creases acoustic pressure. Per manufacturer recommenda- the standardized patient to establish optimal windows.
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tions, a low MI reduces the risk of premature rupture of the
microbubbles that comprise the contrast medium. Thereafter, the standardized patient received perflutren in bo-
lus doses ranging from 0.02mL to 0.1mL, followed by a 10mL
On two devices (the Butterfly IQ3 and the GE Vscan Air), the saline flush. The maximum recommended dose of Definity is
authors were unable to adjust the MI within the recommended one vial, which contains 1.1mL. The dosing was based on guid-
range for optimal contrast visualization. On two additional ance from the Definity representative, who was on site for the
devices, the Fujifilm Sonosite M-Turbo and the Fujifilm Sonos- demonstration. Following the saline flush, the authors raised
ite Edge II, the authors were only able to lower the MI below their right arms over their heads to facilitate contrast circula-
0.3 by using ocular settings; the authors acknowledge that us- tion. Immediately upon injection, another author scanned the
ing an ocular setting for an abdominal ultrasound exam is a right upper quadrant to visualize contrast enhancement of the
non-traditional choice, but it was undertaken for the purpose right kidney.
of decreasing the MI into the recommended range. Although
published protocols specify the use of ultrasound systems with During contrast-enhanced ultrasound of the abdomen, the
contrast software packages, 15,23,24 none of the machines under kidneys are assessed during the arterial phase, while the liver,
review had contrast settings or a contrast software package. spleen, and pancreas are evaluated during the venous phase. 15,21

74 | JSOM Volume 26, Edition 1 / Spring 2026