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Thứ Sáu, 16 tháng 8, 2019

ElastoUS methods reduce unnecessary breast biopsies


By Kate Madden Yee, AuntMinnie.com staff writer
August 15, 2019 -- Using a combination of different elastography methods reduces unnecessary biopsies of BI-RADS 4 lesions without increasing the risk of missing cancers, according to a new study published in the September issue of Ultrasound in Medicine and Biology.
The findings suggest a better way to deal with BI-RADS 4 lesions, which can be tricky to assess for their potential to become malignant, according to a team led by Dr. Jing Han of Sun Yat-Sen University Cancer Center in Guangzhou, China.
"BI-RADS category 4 lesions exhibit a broad range of malignant potential (2% to 95%)," the group wrote (Ultrasound Med Biol, September 2019, Vol. 45:9, pp. 2317-2327). "Therefore, it is necessary to develop a noninvasive and reliable method to discern low-risk lesions as a complement to conventional ultrasound to reduce the unnecessary biopsy rate. Elastography has potential to serve as this valuable tool."
A key modality
Ultrasound is an important modality for breast cancer screening and differentiating benign from malignant lesions, but high false-positive rates can lead to unnecessary biopsies -- making the problem of reducing biopsy of benign lesions without missing cancers a key clinical issue, according to Han and colleagues. Ultrasound elastography may be just the ticket, they noted.
"Ultrasound elastography is beneficial for differentiating breast lesions in many studies," the team wrote. "This technique, which is sensitive to tissue stiffness, has been conducted as a complementary modality for improving breast lesion characterization."
There are a number of elastography techniques: strain (SE), shear wave (SWE), virtual touch imaging (VTi), and virtual touch imaging quantification (VTIQ). Each has its benefits and limitations, and studies have shown that using conventional ultrasound with a single elastography technique can reduce false-positive rates but also increase false-negative rates. Han and colleagues sought to investigate what combinations of strain elastography, VTi, and VTIQ might reduce false positives without increasing false negatives in evaluating BI-RADS category 4 lesions.
The study included 267 patients with 278 BI-RADS 4 lesions who were scheduled for ultrasound-guided biopsy between January 2016 and May 2017. Of the 278 lesions, 151 were benign and 127 were malignant. All were evaluated with conventional B-mode ultrasound, strain elastography, SWE, VTi, and VTIQ (SWE was used with VTIQ; the researchers did not break it out as an individual elastography category for assessment).
Han and colleagues evaluated the following factors: diagnostic performance (including area under the receiver operating characteristic curve, or AUC) sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV).
The group found that VTi alone showed the highest negative predictive value at 91.7%, although combined methods showed higher negative predictive value than single methods, with the highest negative predictive value at 100% when VTi, SE, and VTIQ were combined.
Han's team also found that, compared with conventional ultrasound, positive predictive value increased from 45.7% to 63.1% when combined elastography was added (VTi plus SE plus VTIQ). Of the BI-RADS 4 lesions, 52.5% were downgraded when using a combination of VTi plus SE, and 50.8% were downgraded when using VTi plus strain elastography plus VTIQ -- without missing any cancer.
Performance of elastography techniques for reducing unnecessary biopsy of BI-RADS 4 breast lesions
Performance measure  SE    VTi   VTIQ VTIQ plus VTiVITQ plus SEVTi plus SEVTi, SE, & VTIQ
Sensitivity89.7%92.1%85%96.8%98.4%99.2%100%
Specificity63.5%73.5%84.7%67.5%59.6%52.9%50.9%
Accuracy75.5%82%84.9%80%77.3%74.1%73.4%
PPV67.4%74.5%82.4%71.5%67.2%63.9%63.1%
NPV88%91.7%87%96.2%97.8%98.7%100%
AUC0.820.840.900.820.790.760.75
As for statistical significance, the group found that the specificity and area under the receiver operating curve of VTIQ were significantly higher than those of SE and VTi, and the sensitivity of combined methods was significantly higher than single methods.
Effective combinations
More research is needed to determine the role of combined elastography techniques in reducing unnecessary biopsies of BI-RADS 4 breast lesions, according to Han and colleagues.
"Our initial clinical result revealed that the combination of different types of elastography could improved the sensitivity and negative predictive value, which might serve as a complementary approach to conventional ultrasound to ... reduce unnecessary biopsy for benign breast lesions," the team concluded. "Further studies with a larger population are required to validate our results."

Thứ Sáu, 9 tháng 8, 2019

Cardiac US at bedside boosts disease diagnosis.


By Kate Madden Yee, AuntMinnie.com staff writer
August 6, 2019 -- Adding focused cardiac ultrasonography (FoCUS) to clinical assessment of the cardiovascular health of patients at bedside improves diagnostic yield, according to a study published online August 5 in the Annals of Internal Medicine.
The findings offer clinicians a way to update the traditional "standard of care" bedside evaluation -- that is, a history and physical exam -- for cardiovascular disease, wrote a team led by Dr. Jeffrey Marbach of the University of Ottawa Heart Institute in Ontario, Canada.
"The limited evidence that supports 'classical' signs and symptoms of cardiovascular disease was observed in an era when late-stage presentation was common and detection of disease before onset of symptoms was rare," the authors wrote. "A more sensitive bedside toolkit to detect and quantify pathology before onset of progressive organ damage is increasingly needed, both to triage patients for more formal testing and to allow more rapid clinical decisions at the point of care."
The benefits of POC
Ultrasound has a wide array of imaging capabilities and can be used with everything from superficial vasculature to large intra-abdominal organs to cardiac chambers, the team noted. As such, point-of-care (POC) ultrasound is often used with bedside procedures such as central venous catheter insertion or pericardiocentesis.
The modality's use at bedside hasn't been broadly adopted, even though physical examination is understood to be often inaccurate. But interest in using ultrasound at bedside has increased, Marbach and colleagues wrote.
"Because a small but growing body of literature suggests potential advantages of adjunctive ultrasonography evaluation with physical examination, interest in its accuracy and applicability is increasing," the team wrote. "The possibilities for diagnostic improvement are particularly promising in patients requiring cardiovascular evaluation."
Transthoracic echocardiography has long been used for this purpose; its practitioners are trained in cardiac imaging. Bedside FoCUS offers a quicker, more easily repeatable way to perform a cardiovascular assessment, corresponding author Dr. Benjamin Hibbert, PhD, also of the University of Ottawa Heart Institute, told AuntMinnie.com.
"Our center has been using FoCUS for close to 10 years now, and it has completely changed our practice," he said. "We realized early that adding a FoCUS to physical exam provided meaningful incremental information at the bedside to help in diagnosing and managing our patients. This was even more apparent in our critically ill patients where rapid decisions needed to be made."
Increased sensitivity
For the study, the researchers conducted a review of Medline, Embase, and Web of Science for articles published between January 1990 to May 2019 that compared FoCUS-assisted clinical assessment with clinical assessment alone for the diagnosis of left ventricular systolic dysfunction, aortic or mitral valve disease, or pericardial effusion. They used transthoracic echocardiography as the reference standard. The group included nine studies in its analysis.
The authors found that adding FoCUS to clinical examination at bedside for cardiovascular applications did improve diagnostic yield -- with increased sensitivity and specificity for diagnosing left ventricular dysfunction, and increased sensitivity for diagnosing aortic or mitral valve disease.
Performance of FoCUS when added to clinical exam at bedside
Performance measureClinical assessment aloneFoCUS-assisted clinical examination
Sensitivity
Diagnosing left ventricular dysfunction43%84%
Diagnosing aortic or mitral valve disease46%71%
Specificity
Diagnosing left ventricular dysfunction81%89%
Diagnosing aortic or mitral valve disease94%94%
The findings indicate that using FoCUS with clinical assessment allows for greater detection of disease that might otherwise be missed by clinical assessment alone, Hibbert told AuntMinnie.com.
"The take-home message is that the standard assessment for cardiac pathology is limited, and adding a FoCUS to your assessment markedly increases your ability to detect pathology," he said. "While not directly addressed in this study, the next logical step is going to be seeing if we can use FoCUS to appropriately triage patients for formal echocardiography, which is often performed as a screening test. All healthcare systems are strapped for resources, and if we can rule out significant pathology with a careful exam and FoCUS, we may be able to safely defer formal testing in a large number of patients."l

Thứ Hai, 29 tháng 7, 2019

SWE identifies malignant breast microcalcifications.


By Kate Madden Yee, AuntMinnie.com staff writer
July 29, 2019 -- Ultrasound with a shear-wave elastography (SWE) technique can distinguish benign from malignant breast microcalcifications detected on ultrasound, according to a new study published in the August issue of the American Journal of Roentgenology.
The study findings could help physicians better plan a response to microcalcifications, wrote a team led by Dr. Foucauld Chamming's of Institut Bergonié, Bordeaux Cedex, France.
"On SWE, microcalcifications associated with malignant lesions showed significantly higher stiffness values than benign ones," the group wrote. "In the clinical setting, these results are of particular interest for assessment of concordance between radiologic and pathologic findings."
Digital mammography has long been the gold standard for identifying microcalcifications, but its specificity for characterizing them is low -- ranging from 10% to 67% -- leading to a high number of benign biopsies, the authors noted. Suspicious microcalcifications are often worked up with ultrasound to find signs of invasive cancer and any additional lesions, but conventional ultrasound has its limitations, Chamming's and colleagues wrote (AJR, August 2019, Vol. 213:2, pp. W85-W92).
"Although malignant microcalcifications are more likely to be seen on ultrasound than benign ones, B-mode ultrasound does not provide relevant additional information for the characterization of isolated microcalcifications," they wrote. "Shear-wave elastography, which is able to measure tissue stiffness quantitatively, is a relatively recent ultrasound technique and has been shown to improve characterization of breast lesions, especially masses."
Chamming's and colleagues investigated whether SWE could distinguish benign from malignant microcalcifications of the breast by conducting a study that included 74 patients with mammographically detected suspicious microcalcifications who underwent breast ultrasound between February and June 2016. All of the patients also had an SWE exam; those with malignant microcalcifications were biopsied using ultrasound guidance.
The researchers compared qualitative and quantitative elastography results between benign and malignant calcifications, as well as between pure ductal carcinoma in situ (DCIS) and invasive lesions. They used area under the receiver operating characteristic curves (AUC) to evaluate SWE's performance in detecting malignancy and invasive features of breast lesions.
Ultrasound identified 29 groups of microcalcifications in 29 patients. Pathology results showed 16 benign and 13 malignant groups of microcalcifications.
The authors found that the stiffness of malignant calcifications was higher than benign ones (p = 0.0004). SWE had 100% specificity and positive predictive value for both detecting malignant calcifications and identifying invasive features of breast lesions.
SWE's performance for breast lesions
Performance measureDiagnosis of malignancyDetection of invasive features
AUC0.890.93
Sensitivity69%75%
Specificity100%100%
Negative predictive value80%75%
Positive predictive value100%100%
Accuracy86%85%
The study results could help physicians better manage microcalcifications, according to the authors.
"When faced with stiff calcifications, which have a high probability of being malignant, a biopsy yielding benign results should be questioned, and a second biopsy or surgical excision should be considered," the group concluded.

Thứ Ba, 23 tháng 7, 2019

LUS, HOW to AVOID MISTAKES.

How to avoid mistakes 
in Lung Ultrasound

This commentary provides an excellent review of the misconceptions and problems concerning the application of lung ultrasonography in critically ill patients. Lung ultrasound can have a significant clinical impact in acute care, if used in the appropriate way. (Chest)


Chủ Nhật, 21 tháng 7, 2019

ABVS distinguishes malignant from benign breast lesions.


By Kate Madden Yee, AuntMinnie.com staff writer
July 15, 2019 -- The automated breast volume scanner (ABVS) performs just as well as handheld ultrasound for distinguishing between malignant and benign breast lesions, according to a literature review published in the August issue of Ultrasound in Medicine and Biology.
The findings suggest that clinicians can trust ABVS as an alternative to handheld ultrasound -- which can be affected by user skill variability -- and that it shows promise as a breast imaging technique for both screening and diagnosis, wrote co-authors Dr. Liang Wang and Zhen-Hong Qi of Peking Union Medical College Hospital in Beijing.
"Conventional handheld ultrasound has several inherent limitations, including the operator dependence and the time required for whole-breast examination," they wrote (Ultrasound Med Biol, August 2019, Vol. 45:8, pp. 1874-1881). "In contrast, the automated breast volume scanner has several advantages over handheld ultrasound, such as higher reproducibility, less operator dependence, and less time required for image acquisition."
Most radiologists continue to use handheld ultrasound to characterize breast lesions identified on mammography or other screening modalities, and the diagnostic performance of ABVS is controversial, Wang and Qi noted. To better assess this, the two conducted a literature review of PubMed, Embase, and Cochrane Library databases.
Their research included nine studies with 1,985 lesions from 1,774 patients; of the lesions, 628 were malignant and 1,357 were benign. Wang and Qi evaluated the following performance measures for the two techniques: sensitivity, specificity, positive and negative likelihood ratios, and diagnostic odds ratios.
Across all measures, ABVS performed comparably to handheld ultrasound for distinguishing benign from malignant breast lesions, the researchers found.
Comparison of handheld ultrasound and ABVS for distinguishing benign from malignant breast lesions
Performance measureHandheld ultrasoundABVS
Sensitivity90.6%90.8%
Specificity81%82.2%
Positive likelihood ratio5.225.39
Negative likelihood ratio0.110.10
Diagnostic odds ratio52.6061.68
Area under the receiver operating characteristic curve0.940.93
"On the basis of our data, the ABVS and handheld ultrasound exhibited similar sensitivity and specificity in the differentiation of malignant and benign breast lesions," Wang and Qi wrote.
They cautioned that these results were based on grayscale ultrasound interpretation, meaning that only morphological features were displayed, rather than functional information that elastography and Doppler ultrasound offer.
"Both elastography and Doppler ultrasound can provide independent diagnostic information in addition to the grayscale imaging, which could significantly improve the diagnostic accuracy for breast ultrasound," they wrote.
But ABVS does have an advantage over handheld ultrasound that could make it a valuable tool in clinical practice: its ability to gather additional morphological information on the reconstructed coronal plane.
"The retraction phenomenon on the coronal plane of the ABVS is regarded as a highly diagnostic feature in the differentiation of benign and malignant breast lesions," the researchers wrote. "Therefore, it seems reasonable that the ABVS may be superior to handheld ultrasound in differential diagnosis with the help of coronal reconstruction."

Thứ Năm, 4 tháng 7, 2019

US and Astronaut Spinal Anatomy and Disorders.




Abstract


Objectives

Back pain is one of the most common conditions of astronauts during spaceflight and is hypothesized to be attributed to pathologic anatomic changes. Ultrasound (US) represents the only available imaging modality on the International Space Station, but a formal US protocol for imaging the structures of the spinal column does not exist. This investigation developed a method of acquiring diagnostic‐quality images of the anterior lumbar and cervical regions of the spine during long‐duration spaceflight.

Methods

Comprehensive spinal US examinations were conducted on 7 long‐duration spaceflight astronauts before flight, in flight, and after flight and compared to preflight and postflight magnetic resonance imaging data. In‐flight scans were conducted after just‐in‐time training assisted by remote expert tele‐US guidance.



Results

Novice users were able to obtain diagnostic‐quality spinal images with a 92.5% success rate. Thirty‐three anomalous or pathologic findings were identified during the preflight US analysis, and at least 14 new findings or progressions were identified during the postflight US analysis. Common findings included disk desiccation, osteophytes, and qualitative changes in the intervertebral disk height and angle.

Conclusions

Ultrasound has proven efficacy as a portable and versatile diagnostic imaging modality under austere conditions. We demonstrated a potential role for US to evaluate spinal integrity and alterations in the extreme environment of space on the International Space Station. Further investigations should be performed to corroborate this imaging technique and to create a larger database related to in‐flight spinal conditions during long‐duration spaceflight.