Elastography shows high reproducibility in breast lesions.

By Theresa Pablos, AuntMinnie staff writer

January 24, 2020 -- Two different ultrasound elastography techniques -- strain elastography (SE) and shear-wave elastography (SWE) -- showed high interoperator reproducibility when scanning breast lesions in a new study, published on January 21 in Ultrasound in Medicine and Biology.

Repeatability is critical to test the clinical effectiveness of imaging technologies. In the study, two experienced operators used the same probe on the same ultrasound system to test how reliably SE and SWE showed the same result when imaging breast lesions.

While SE performed slightly better for malignant lesions, both ultrasound elastography techniques demonstrated good to excellent agreement.

"Under the same operating conditions, our results indicated the excellent reproducibility of SE and SWE in assessing breast neoplasms among well-trained operators," wrote the authors, led by Dr. Lu Zhang from the Shanghai Jiaotong University School of Medicine.

Clinicians use SE and SWE to assess the stiffness of masses or tissue, but the two techniques use different methods to acquire images. While SE acquires an image by compressing or pulsing to displace tissue, SWE uses acoustic pressure to create an image of tissue stiffness. The researchers wondered whether these differences would affect interoperator reliability for benign and malignant lesions.

To find out, two blinded radiologists with more than three years of clinical experience performed breast ultrasound examinations on 91 women with pathologically confirmed breast lesions. The researchers excluded women with cystic or mixed lesions, lesions with coarse calcifications, and tumors that exceeded elastography's region of interest.

The radiologists acquired two SE images (nodule outline drawn and not drawn) and three SWE images (quality control, nodule outline drawn, and nodule outline not drawn) using the Resona 7 ultrasound system (Mindray Medical) with an L11-3 probe. An image was deemed satisfactory when the quality control scale at the bottom of the image reached a stable stage.

Diagnostic performance of SE and SWE
	Sensitivity		Specificity
	Operator 1	Operator 2	Operator 1	Operator 2
Elastic score (SE)	58%	59%	95%	88%
Strain ratio (SE)	71%	57%	78%	92%
Mean elastic modulus (SWE)	58%	45%	78%	93%
Max elastic modulus (SWE)	71%	52%	88%	100%
Minimum elastic modulus (SWE)	48%	19%	80%	95%
Standard deviation of elastic modulus (SWE)	65%	74%	87%	73%

Both SE and SWE showed satisfactory repeatability, the researchers found. For SE, operators' evaluation results showed no significant difference. For SWE, all scores except for minimum elastic modulus showed promising repeatability.

In addition, specificities were higher than sensitivities for both types of ultrasound, and both SE and SWE performed well on all types of lesions.

"It is generally believed that the reproducibility of SE is lower than that of SWE," the authors wrote. "However, our study found that the reproducibility of both SE and SWE breast lesions is very satisfactory except for [minimum elastic modulus of SWE], which may explain the very similar diagnostic performance of SE and SWE by the two operators."

One limitation of the study was its small sample size, and the researchers urged future, larger studies to confirm their findings. In addition, SE and SWE should still be considered adjunct modalities to B-mode ultrasound because of the high specificity and low sensitivity findings.

"In our study, SE and SWE had high specificity but relatively low sensitivity, which reminds us not to overestimate the value of elastography in the diagnosis of breast nodules," they wrote.
"We still need to rely on B-mode ultrasound with elastography as an auxiliary model."

2 US features predict cancer recurrence risk.

By Theresa Pablos, AuntMinnie staff writer

January 23, 2020 -- Machine learning might one day be able to tell which breast cancer patients will benefit from additional genetic testing. In a recent study, researchers used natural language processing to identify key features from ultrasound reports associated with cancer recurrence risk.

The study included hundreds of women with breast cancer who had previously undergone genetic tests, also known as transcriptomic tests, to determine their risk of cancer recurrence. After using a script to parse the women's BI-RADS ultrasound findings, the researchers found two key features that may identify when a patient could benefit from additional testing.

"Ultrasound findings, notably the 'retrotumoral' and 'margins' features, if abnormal, may help provide justification to obtain one of the transcriptomic tests," wrote the authors, led by Dr. Neema Jamshidi, PhD, a diagnostic radiologist from the University of California, Los Angeles (UCLA) David Geffen School of Medicine (Plos One, January 10, 2020). "Future multi-institutional prospective studies will be important in determining if these observations persist in larger cohorts."

The researchers acquired data from the electronic health records of 219 patients with breast cancer at the Harbor-UCLA Medical Center between April 2008 and January 2013. All patients had an ultrasound scan performed when they were first diagnosed with breast cancer. They also all had either an Oncotype DX or MammaPrint test to identify their risk of cancer recurrence.

The researchers coded a custom script to analyze the BI-RADS findings from the descriptive terminology from the women's initial ultrasound scans. Their program searched the terminology and attempted to find words or phrases associated with cancer reoccurrence risk.

In particular, three sonographic features -- "margins," "retrotumoral," and "internal echoes" -- were correlated with the genetic test results. The features "margins" and "retrotumoral" appeared in both the MammaPrint and Oncotype DX classification trees, while "internal echoes" only appeared in the MammaPrint classification tree.

...

The researchers hope future studies use more patients to determine whether atypical findings related to "margins" and "retrotumoral" features can truly help determine which patients would benefit from genetic testing. They also hope studies will evaluate other types of genetic tests.

US and HCC on Obese Patients.

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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.

Model predicts metastases in endometrial cancer patients

By Rebekah Moan, AuntMinnie.com contributing writer

January 2, 2020 -- Using ultrasound in combination with endometrial biopsy results and clinical characteristics allows clinicians to reliably predict the risk of lymph node metastases in endometrial cancer patients before surgery. Researchers found the model to be superior to risk stratification alone in a study published online December 16 in Ultrasound in Obstetrics and Gynecology.

The prospective multicenter study compared three ways to assess metastases: endometrial biopsy alone, biopsy with ultrasound, and biopsy with ultrasound and risk characteristics. The study team led by Dr. Linda Eriksson from the pelvic cancer department at Karolinska University Hospital in Stockholm found the method using all three showed higher sensitivity and specificity.

"Our risk prediction model can be used to decide which women should or should not be subject to lymphadenectomy or sentinel node biopsy, depending on the individual risk of lymph node metastases," they wrote.

Comparing modalities

Lymphadenectomy is required for surgical staging in endometrial cancer, but it doesn't have any survival advantages in early-stage endometrial cancer and isn't recommended in low-risk cases. Using transvaginal ultrasound or MRI along with preoperative biopsy helps to determine the necessity of lymphadenectomy.

What can further refine the process is a preoperative risk prediction model to assess the risk of lymph node metastases before surgery -- to avoid undertreatment or overtreatment with lymphadenectomy.

Previous research has relied on small, retrospective studies that use MRI to create a prediction model. However, transvaginal ultrasound demonstrates similar accuracy to MRI and has the advantage of being accessible, well-tolerated, less expensive, and less time-consuming.

In the current study, Eriksson and colleagues sought to develop a preoperative risk prediction model with variables from demography, endometrial biopsy, and ultrasound to estimate the individual risk of lymph node metastases in endometrial cancer patients. They then compared its performance with endometrial biopsy results alone or endometrial biopsy results combined with ultrasound findings.

The study included 1,501 women with histologically confirmed endometrial cancer from 16 centers in seven European countries. The women were subjected to transvaginal ultrasound before surgery. The information they included to assess risk was age, duration of abnormal bleeding, result of preoperative endometrial biopsy (histotype and grade), tumor extension according to ultrasound, color content of the endometrial scan, tumor size according to ultrasound, and "undefined tumor with an unmeasurable endometrium."

The individual predicted risk of lymph node metastases was obtained by multiplying each risk factor by its prediction coefficient and adding the intercept.

Clinicians performed lymphadenectomy in 691 women, of whom 127 had lymph node metastases. Endometrial biopsy and endometrial biopsy combined with ultrasound have fixed sensitivities and specificities, but the risk prediction model does not -- it can be shifted upward to obtain a better specificity or downward to obtain a better sensitivity based on different threshold levels. For a comparison, see the table below.

Lymph node metastatic risk model vs. endometrial biopsy and ultrasound
	Endometrial biopsy	Endometrial biopsy + ultrasound	Risk model at threshold of 0.196	Risk model at threshold of 0.113
Sensitivity	35%	75%	50%	80%
Specificity	77%	52%	80%	53%

Even when the researchers continued to fiddle with the risk threshold, it outperformed both endometrial biopsy alone and endometrial biopsy combined with ultrasound. They also found the overall area under the curve of the risk prediction model was 0.73.

"The use of a risk prediction model can aid in planning the expected operation room time and the need of a skilled surgeon," Eriksson and colleagues wrote. "If implemented at the point of care, the model can be integrated into ultrasound machines or apps that automatically calculate the risk of lymph node metastases."

Given the large sample size and the multicenter design, the study is likely generalizable. However, further validation on new data is needed, preferably with known sentinel node outcome in cases without lymphadenectomy.

"After successful external validation, an impact analysis (i.e., decision-analytic modeling, a cost-effectiveness analysis, a before-after implementation study, or a randomized trial) would add to the evidence required before introducing the model into clinical practice," the researchers concluded.

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