Top-cited publications on point-of-care ultrasound: The evolution of research trends.

Liao SF, et al. Am J Emerg Med. 2018.

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Abstract

STUDY OBJECTIVES: Point-of-care ultrasound (POCUS) has been a rapidly growing and broadly used modality in recent decades. The purpose of this study was to determine how POCUS is incorporated into clinical medicine by analyzing trends of use in the published literature.

METHODS: POCUS-related publications were retrieved from the Web of Science (WoS) database. The search results were ranked according to the number of times an article was cited during three time frames and average annual number of citations. Of the top 100 most cited publications in the four rankings, information regarding the publication journal, publication year, first author's nationality, field of POCUS application, and number of times the article was cited was recorded for trend analysis.

RESULTS: A total of 7860 POCUS-related publications were retrieved, and publications related to POCUS increased from 8 in 1990 to 754 in 2016. The top 148 cited publications from the four ranking groups were included in this study. Trauma was the leading application field in which POCUS was studied prior to 2001. After 2004, thorax, cardiovascular, and procedure-guidance were the leading fields in POCUS research. >79% (118/148) of the top-cited publications were conducted by authors in the United States, Italy, and France. The majority of publications were published in critical care medicine and emergency medicine journals.

CONCLUSIONS: In recent years, publications relating to POCUS have increased. POCUS-related research has mainly been performed in thorax, cardiovascular, and procedure-guidance ultrasonography fields, replacing trauma as the major field in which POCUS was previously studied.

Copyright © 2018 Elsevier Inc. All rights reserved.

PMID

 29321113 [Indexed for MEDLINE

Third-trimester ultrasound finds undetected fetal abnormalities.

By Kate Madden Yee, AuntMinnie.com staff writer

October 15, 2019 -- Almost a quarter of fetal abnormalities are identified for the first time during routine ultrasound at 35 to 37 weeks gestation, according to a study published on October 8 in Ultrasound in Obstetrics & Gynecology.

he study results suggest that ultrasound at this juncture of pregnancy could offer women and their babies needed support, wrote a team led by Dr. Alessandra Ficara of King's College Hospital in London.

"A high proportion of fetal abnormalities are detected for the first time during a routine ultrasound examination at 35 to 37 weeks gestation," the group wrote. "Such diagnosis and subsequent management, including selection of timing and place for delivery and postnatal investigations, could potentially improve postnatal outcome."

Assessing pregnancy at 35 to 37 weeks gestation with ultrasound helps predict the development of preeclampsia and plan delivery of a baby that is small or large for their gestational age, Ficara's team noted. But ultrasound can also identify abnormalities overlooked on early ultrasound exams.

To investigate this, Ficara and colleagues included data from 52,400 single-fetus pregnancies in women undergoing routine ultrasound exams between 35 and 37 weeks gestation.

All the women had also undergone ultrasound scans at 18 to 24 weeks of pregnancy; 47,214 had scans at 11 to 13 weeks as well. The team included pregnancies that resulted in live births or stillbirths but excluded those with known chromosomal abnormalities.

Overall, incidence of fetal abnormalities was 1.9%. Of these, 67.7% were diagnosed on ultrasound during the first or second trimester, but 24.8% were diagnosed for the first time at 35 to 37 weeks.

The most common abnormalities first identified on first- or second-trimester ultrasound but confirmed on third-trimester ultrasound included the following:

• Abdominal cyst or gastroschisis
• Cleft lip and palate
• Congenital pulmonary airway malformation
• Duplex kidney
• Hydronephrosis
• Polydactyl
• Talipes
• Unilateral multicystic kidney
• Unilateral renal agenesis and/or pelvic kidney
• Ventricular septal defect
• Ventriculomegaly

But a number of abnormalities were first identified on third-trimester ultrasound:

• Arachnoid cyst
• Duplex kidney
• Hydronephrosis
• Mild ventriculomegaly
• Ovarian cyst
• Ventricular septal defect

The study findings suggest that there's definitely a place for third-trimester ultrasound when it comes to improving pregnancy outcomes, according to the team.

"This study has highlighted the additional benefit of the late third-trimester scan in the detection of fetal abnormalities that were either missed at previous first- and second-trimester scans or became apparent only during the third trimester," the group concluded.

POCUS, MRI make ECRI's top 10 hazards list

By Kate Madden Yee, AuntMinnie.com staff writer

October 9, 2019 -- Point-of-care ultrasound (POCUS) and missing patient implant data for MRI exams are listed among the top 10 health technology hazards for 2020, according to a new report released October 7 by healthcare consultancy ECRI Institute.

POCUS scanners are portable, relatively inexpensive, and easy to use -- all features that have contributed to their rapid adoption into clinical practice, ECRI noted. But POCUS's speedy implementation has "outpaced policies and practices that could prevent misuse or misdiagnosis," the institute said.

Safety concerns around POCUS include using the technology inappropriately, misdiagnoses, and overdependence on portable ultrasound when a patient really needs a more comprehensive imaging exam.

"Safeguards for ensuring that POCUS users have the requisite training, experience, and skill have not kept pace with the speed of adoption," ECRI said. "The lack of sufficient oversight increases the potential that patients will be adversely affected by problems associated with use, or lack of use, of the technology."

The institute suggests that POCUS quality assurance policies should address user training and credentialing, exam documentation, and data archiving.

As for MRI, the report calls specific attention to missing patient implant data, which can put patients in danger and delay MRI exams.

"Some implants can heat, move, or malfunction when exposed to an MRI system's magnetic field," the ECRI said. "Thus, MRI staff must identify and follow any contraindications or conditions for safe scanning prescribed by the implant manufacturer."

But information about patient implants can be difficult to track down, since there is often no single place within the electronic health record (EHR) to make note of it, according to ECRI.

"Direct harm to the patient is possible if a scan is inappropriately conducted in the presence of an unidentified implant," the ECRI said. "Also, the patient's treatment can be adversely affected if a scan needs to be postponed while care providers search for implant information. Healthcare facilities should work with their EHR provider to create an implant list stored within the patient record."

Other hazardous issues on the ECRI list include surgical stapler misuse, sterile processing errors in medical and dental offices, unproven surgical robotic procedures, medication timing errors in patient EHRs, and loose nuts and bolts in medical equipment.

"[This] list identifies the potential sources of danger that we believe warrant the greatest attention for the coming year," ECRI said. "The list does not enumerate the most frequently reported problems or the ones associated with the most severe consequences -- although we do consider such information in our analysis. Rather, the list reflects our judgment about which risks should receive priority now."

Elastography helps liver transplant patients avoid biopsy.

By Kate Madden Yee, AuntMinnie.com staff writer

October 8, 2019 -- Ultrasound with a shear-wave elastography (SWE) technique can help liver transplant patients avoid biopsy on follow-up, according to a study published online October 7 in the American Journal of Roentgenology.

The findings are good news for a patient population often vulnerable to invasive procedures after transplant -- and can help save healthcare resources, wrote a team led by Dr. Corinne Deurdulian of the University of Southern California in Los Angeles.

"Given the significant resources allotted to perform liver biopsies (e.g., radiologist time, nursing staff, and hospital resources) and patient recovery time, as well as patient discomfort and the possibility of significant postbiopsy complications developing, utilization of a noninvasive tool to determine the degree of hepatic fibrosis would be useful in the initial assessment and follow-up of liver transplant patients," the group wrote.

After liver transplant, patients are monitored for both possible rejection of the new organ and hepatic fibrosis, and they often undergo liver biopsies as part of this follow-up, Deurdulian and colleagues noted.

The researchers sought to determine whether shear-wave elastography could offer a noninvasive alternative to biopsy to assess for liver fibrosis, helping clinicians quantify it in liver transplant recipients.

The study included 111 adult liver transplant patients who underwent 147 SWE exams of the right hepatic lobe followed by biopsies between May 2015 and December 2017. The researchers compared SWE values with fibrosis scores of biopsy samples using the Metavir system: Metavir scores are F0 (no fibrosis), F1 (portal fibrosis without septa), F2 (portal fibrosis with few septa), F3 (numerous septa without cirrhosis), and F4 (cirrhosis). The team tracked SWE's sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy.

Of the 147 SWE exams and liver biopsies, the researchers found consistent threshold values for patients with Metavir scores of F0 and F1 (no or minimal fibrosis), compared with those with Metavir scores of F2, F3, or F4 (significant fibrosis).

SWE's performance in classifying fibrosis
Performance measure	SWE
SWE value
No or minimal fibrosis	≤ 1.76 m/sec
Significant fibrosis	> 1.76 m/sec
Other performance measures
Sensitivity	77%
Positive predictive value	33%
Negative predictive value	96%

The study results suggest that clinical decisions for liver transplant patients can be based on SWE results rather than biopsy, the researchers concluded.

"If the median SWE value is 1.76 [m/sec] or less, the patient can be classified as having no or minimal fibrosis ... and can avoid biopsy," the group concluded. "According to these results, which have a negative predictive value of 96%  liver biopsies may be obviated in most patients."

Radiofrequency ultrasound , AI predict thyroid cancer.

Radiofrequency ultrasound , AI predict thyroid cancer
By Kate Madden Yee, AuntMinnie.com staff writerRadiofrequency ultrasound and an artificial intelligence (AI) model can be used to effectively predict the malignancy of thyroid nodules, as well as stratify their risk, according to a study set for publication in the November issue of Ultrasonics.

The combination of radiofrequency ultrasound with an artificial neural network (ANN) could also avoid operator dependency issues and help prevent unnecessary thyroid biopsies, according to a group led by Dr. Chunrui Liu of the Affiliated Hospital of Nanjing University Medical School in China.

"The proposed method has no operator dependency; all of the analyses are performed by computer," the team noted (Ultrasonics, November 2019, Vol. 99, pp. 1-9). "Preliminary results indicated that the performance of ANN combined with radiofrequency ultrasound signals is better than that combined with conventional ultrasound images."

Common but not often malignant

Thyroid nodules are common, but only 8% to 16% are actually malignant, according to the researchers. Many ultrasound techniques are used to evaluate nodule malignancy, including strain elastography, acoustic radiation force impulse imaging, and contrast-enhanced ultrasound, but these methods' efficacy remains unclear, the group wrote.

That's where radiofrequency ultrasound comes in. The technique elicits more clinical information than conventional ultrasound by extracting radiofrequency signals from tissues. But how it performs with thyroid nodules has not been studied, Liu and colleagues noted.

"Preliminary studies of radiofrequency ultrasound have been promising, and the method has been shown to have broader prospective applications in identifying prostate and breast cancers and grading fatty liver," they wrote. "To date, few studies on radiofrequency ultrasound's thyroid cancer detection performance have been reported."

The researchers developed their method to predict suspicious thyroid nodules by first gathering radiofrequency data and then creating radiofrequency ultrasound images using Matlab software (MathWorks). After a radiologist outlined regions of interest on the images, textural features were then analyzed using the gray-level co-occurrence matrix (GLCM) algorithm and principal component analysis. The resulting characteristic values from the textural analysis were subsequently used to train the ANN.

The study included 131 pathologically proven thyroid nodules, of which 59 were benign and 72 were malignant. The nodules were randomly divided into training, validation, and testing cohorts. To test their hypothesis that radiofrequency ultrasound could provide more tissue characteristic information than conventional ultrasound, the researchers also performed the same texture and ANN analyses on the B-mode ultrasound images.

The ANN algorithm performed better with radiofrequency ultrasound than it did on conventional ultrasound in all categories except specificity, the group found.

ANN performance for predicting thyroid nodule malignancy
Performance measure	ANN on conventional ultrasound images	ANN on radiofrequency ultrasound images
Sensitivity	94.4%	100%
Specificity	93.2%	91.5%
Accuracy	93.9%	96.2%
AUC*	0.917	0.945

*AUC = Area under the curve

The group also used the ANN with radiofrequency ultrasound to characterize new malignancy risk groups for categories 3 (probably benign), 4 (suspicious), and 5 (probably malignant) thyroid nodules as established by the American College of Radiology's Thyroid Imaging Reporting and Data System (TI-RADS). The new categories better distinguished malignant nodules compared with TI-RADS.

Parameter	Category 3	Category 4	Category 5
No. of samples	42	16	73
No. of malignant samples	0	3	69
Risk of malignancy
ANN plus radiofrequency ultrasound	0	18.8%	94.5%
TI-RADS	0	55.1%	88.2%

"The new categories allow for a selection of suspicious nodules to be submitted to fine-needle aspiration, thereby avoiding unnecessary thyroid biopsies," the group wrote.

More research to come

More research needs to be done to establish the benefits of using an ANN and radiofrequency ultrasound, according to Liu and colleagues.

"Of course, although these preliminary results suggested [the use of the ANN and radiofrequency ultrasound] could help sonographers to identify risky thyroid nodules and reduce the number of unnecessary thyroid biopsies, more data will be collected and analyzed in our future study to further confirm the feasibility and accuracy of the proposed method," they concluded.