Pulsed US shows promise as cancer therapy.

By AuntMinnie.com staff writers

January 8, 2020 -- A new form of low-intensity pulsed ultrasound therapy shows promise for destroying cancerous tumors without harming nearby healthy cells, according to research published online January 7 in Applied Physics Letters.

The therapy works by tuning the ultrasound frequency to match that of specific cancer cells -- similar to how an opera singer can shatter a wine glass by loudly singing a precise note. As a result, the researchers can use lower-intensity ultrasound beams.

In the study, researchers from the California Institute of Technology and City of Hope Beckman Research Institute used the technique to disrupt breast, colon, and leukemia cancer cell models in suspension without harming healthy immune or red blood cells.

"This project shows that ultrasound can be used to target cancer cells based on their mechanical properties," stated David Mittelstein, an MD/PhD candidate at CalTech and lead author on the paper, in a press release. "This is an exciting proof of concept for a new kind of cancer therapy that doesn't require the cancer to have unique molecular markers or to be located separately from healthy cells to be targeted."

US detects astronaut's blood clot in space

By Abraham Kim, AuntMinnie.com staff writer

January 7, 2020 -- An astronaut on the International Space Station using an onboard ultrasound scanner to research the effects of space flight instead detected their own venous thrombosis, according to an article published in the January 2 issue of the New England Journal of Medicine.

Two months into a six-months-long mission on the International Space Station, the astronaut identified a potential blood clot while performing a self-directed ultrasound exam as part of a vascular research study. A follow-up ultrasound exam performed by the astronaut with guidance from two radiologists on Earth confirmed that the blood clot was a deep vein thrombosis (DVT) in the jugular vein of the neck (NEJM, January 2, 2020, Vol. 382:1, pp. 89-90).

Treatment of the condition typically entails taking blood-thinning medication for several months to prevent the clot from growing and moving to a different part of the body, noted co-author Dr. Stephen Moll in a statement released by the University of North Carolina School of Medicine. Moll is a professor of medicine at the university and a member of its Blood Research Center.

"There is some risk when taking blood thinners that if an injury occurs, it could cause internal bleeding that is difficult to stop. ... Knowing there are no emergency rooms in space, we had to weigh our options very carefully," he said.

Moll discussed treatment options with a team of NASA physicians and finally advised the astronaut to take a blood thinner for approximately 90 days, with regular ultrasound exams guided by radiologists to monitor the blood clot. The medical team also advised the astronaut to stop taking the blood thinner four days before the journey back home to Earth due to the high physical demands involved in the reentry process.

The International Space Station. Image courtesy of NASA.

After landing on Earth, the astronaut underwent a point-of-care ultrasound exam that indicated the astronaut no longer required further treatment for DVT. The astronaut remained asymptomatic on a follow-up exam six months after returning to Earth, the authors found.

The case of DVT in spaceflight underscores the complexities of space medicine, which, for this astronaut, included patient-performed, radiologist-guided ultrasonography, Moll and colleagues noted. The case revealed gaps in current understanding of circulatory and hemostatic physiology in space, as well as the need for more research on how blood and blood clots behave in space.

"How do you minimize risk for DVT?" Moll said. "Should there be more medications for it kept on the International Space Station? All of these questions need answering, especially with the plan that astronauts will embark on longer missions to the moon and Mars."

US of Infants exposed to Zika predicts long-term risk

By Theresa Pablos, AuntMinnie.com contributing writer

January 6, 2020 -- Some infants who were exposed to the Zika virus in utero but who appeared normal at birth later demonstrated delays in development as toddlers, according to a study published online January 6 in JAMA Pediatrics. But imaging tools such as ultrasound and MRI can help indicate which children might be at increased risk.

Researchers found that infants whose postnatal ultrasound images showed nonspecific findings, such as lenticulostriate vasculopathy, were significantly more likely to experience impaired social cognition development as toddlers than the other infants who were exposed to the Zika virus in utero.

"Although many of the infants in this cohort study had normal neurodevelopmental scores through 18 months of age, scores in multiple areas of development for some infants decreased from normative mean scores over time," wrote the authors, led by Dr. Sarah Mulkey, PhD, from Children's National Hospital in Washington, DC.

Exposure to the Zika virus before birth can cause brain abnormalities, as well as eye and vision problems. While some infants exposed in utero to Zika develop symptoms detectable through ultrasound and other imaging modalities, most newborns do not have any clinical manifestations of congenital Zika syndrome (CZS). However, these apparently healthy infants are still at risk for long-term negative health effects, including neurodevelopmental delay.

The researchers performed neurodevelopmental assessments on 70 children from Colombia who were exposed to the Zika virus in utero but had no signs of congenital Zika syndrome before or at birth. They administered the tests when the children were 4 months to 8 months old and/or 9 months to 18 months old.

In one of the clinical tests, the children showed a consistent and moderate neurodevelopmental decline. Their scores for mobility, communication, and social cognition decreased throughout the assessment period compared with the standard scores for children in their age ranges.

"The infants included in the present cohort were well characterized, with laboratory-confirmed in utero exposure to [Zika virus], normal fetal MRI and ultrasonography findings, and no evidence of CZS or microcephaly at birth," the authors wrote. "Thus, these infants were expected to have low risk for subsequent neurodevelopmental deficits, yet these deficits emerged in the first year of life and without a reduction in head circumference."

About 60 of the children in the study had also received cranial ultrasound as infants. One-third of the children showed mild, nonspecific findings, including lenticulostriate vasculopathy, subependymal or germinolytic cyst, choroid plexus cyst, and isolated calcification.

The children with these ultrasound findings were more likely than those with normal findings to experience a decline in social cognition, the researchers found. They noted that this could be a risk factor for worse early neurodevelopmental outcomes.

"To our knowledge, this study is the first to show that these nonspecific imaging findings may indicate subtle brain injury potentially associated with impaired neurological development," the authors wrote.

They cautioned that their study included a relatively small sample size, and no concurrent control group was used. Nevertheless, the findings suggest the importance of pre- and postnatal imaging for infants exposed to the Zika virus, as noted in an editorial letter from experts at the U.S. Centers for Disease Control and Prevention (CDC).

"In the cohort followed by Mulkey et al, nonspecific findings on postnatal imaging ... were associated with lower scores in the social cognition domain," wrote Margaret Honein, PhD, and her CDC colleagues. "Although the clinical significance of these nonspecific findings is not yet clear, the importance of postnatal neuroimaging for all children with Zika virus exposure in utero was made extremely clear."

Patients prefer Ultrasound first.

By AuntMinnie.com staff writers

December 23, 2019 -- About 40% of patients want their primary care doctors to have access to handheld ultrasound devices for quick use when needed during appointments, according to a consumer survey commissioned by GE Healthcare.

However, another survey commissioned by the company revealed general practitioners didn't feel strongly about integrating new technologies into their practices, proving that the two groups aren't seeing eye-to-eye when it comes to new innovations.

One survey included 500 general practitioners from New York, Florida, California, Illinois, and Texas who completed a six-question survey over the phone. The consumer study included 1,000 adults in the U.S. who answered questions online.

On a positive note, about 37% of doctors currently were using the tools or were interested in using them.

Those who used them said the devices made a difference at their practices. About 60% of handheld ultrasound users felt it positively impacted their practices, and 85% of doctors who use the tool feel it will impact the healthcare industry.

Technology use appealed to most patients. About 50% of consumers think their doctors should make use of the latest medical technology, such as handheld ultrasound, if it is affordable, according to the consumer survey.

Noncontact Laser US Imaging.

Abstract

Full noncontact laser ultrasound (LUS) imaging has several distinct advantages over current medical ultrasound (US) technologies: elimination of the coupling mediums (gel/water), operator-independent image quality, improved repeatability, and volumetric imaging. Current light-based ultrasound utilizing tissue-penetrating photoacoustics (PA) generally uses traditional piezoelectric transducers in contact with the imaged tissue or carries an optical fiber detector close to the imaging site. Unlike PA, the LUS design presented here minimizes the optical penetration and specifically restricts optical-to-acoustic energy transduction at the tissue surface, maximizing the generated acoustic source amplitude. With an appropriate optical design and interferometry, any exposed tissue surfaces can become viable acoustic sources and detectors. LUS operates analogously to conventional ultrasound but uses light instead of piezoelectric elements. Here, we present full noncontact LUS results, imaging targets at ~5 cm depths and at a meter-scale standoff from the target surface. Experimental results demonstrating volumetric imaging and the first LUS images on humans are presented, all at eye- and skin-safe optical exposure levels. The progression of LUS imaging from tissue-mimicking phantoms, to excised animal tissue, to humans in vivo is shown, with validation from conventional ultrasound images. The LUS system design insights and results presented here inspire further LUS development and are a significant step toward the clinical implementation of LUS.