Elastogram: Physics, Clinical Applications, and Risks

Recent advances in optical elastography and emerging opportunities in the basic sciences and translational medicine [Invited]

Optical elastography offers a rich body of imaging capabilities that can serve as a bridge between organ-level medical elastography and single-molecule biophysics. We review the methodologies and recent developments in optical coherence elastography, Brillouin microscopy, optical microrheology, and photoacoustic elastography. With an outlook toward maximizing the basic science and translational clinical impact of optical elastography technologies, we discuss potential ways that these techniques can integrate not only with each other, but also with supporting technologies and capabilities in other biomedical fields. By embracing cross-modality and cross-disciplinary interactions with these parallel fields, optical elastography can greatly increase its potential to drive new discoveries in the biomedical sciences as well as the development of novel biomechanics-based clinical diagnostics and therapeutics.

Deep learning in ultrasound elastography imaging: A review

It is known that changes in the mechanical properties of tissues are associated with the onset and progression of certain diseases. Ultrasound elastography is a technique to characterize tissue stiffness using ultrasound imaging either by measuring tissue strain using quasi-static elastography or natural organ pulsation elastography, or by tracing a propagated shear wave induced by a source or a natural vibration using dynamic elastography. In recent years, deep learning has begun to emerge in ultrasound elastography research. In this review, several common deep learning frameworks in the computer vision community, such as multilayer perceptron, convolutional neural network, and recurrent neural network are described. Then, recent advances in ultrasound elastography using such deep learning techniques are revisited in terms of algorithm development and clinical diagnosis. Finally, the current challenges and future developments of deep learning in ultrasound elastography are prospected. This article is protected by copyright. All rights reserved.

Ultrasound imaging of preterm brain injury: fundamentals and updates

Neurosonography has become an essential tool for diagnosis and serial monitoring of preterm brain injury. Preterm infants are at significantly higher risk of hypoxic-ischemic injury, intraventricular hemorrhage, periventricular leukomalacia and post-hemorrhagic hydrocephalus. Neonatologists have become increasingly dependent on neurosonography to initiate medical and surgical interventions because it can be used at the bedside. While brain MRI is regarded as the gold standard for detecting preterm brain injury, neurosonography offers distinct advantages such as its cost-effectiveness, diagnostic utility and convenience. Neurosonographic signatures associated with poor long-term outcomes shape decisions regarding supportive care, medical or behavioral interventions, and family members' expectations. Within the last decade substantial progress has been made in neurosonography techniques, prompting an updated review of the topic. In addition to the up-to-date summary of neurosonography, this review discusses the potential roles of emerging neurosonography techniques that offer new functional insights into the brain, such as superb microvessel imaging, elastography, three-dimensional ventricular volume assessment, and contrast-enhanced US.

Clinical application of cervical shear wave elastography in predicting the risk of preterm delivery in DCDA twin pregnancy

Background

Limited studies have used cervical shear wave elastography (SWE) as a tool to investigate the predictive effect of cervical changes on preterm delivery (PTD) in twin pregnancy. This study is aimed to predict the risk of PTD by cervical SWE in dichorionic diamniotic (DCDA) twin pregnancy.

Methods

A total of 138 women with dichorionic diamniotic (DCDA) twins were included in this prospective study. The mean SWE value of the cervix was obtained from the inner, middle and outer regions of the anterior and posterior cervical lips using a transvaginal ultrasound transducer and measured consecutively across three different gestations (20–23^+ 6 weeks, 24–27^+ 6 weeks, and 28–32 weeks). Follow-up was performed on all subjects, and we compared the mean SWE value between the PTD and term delivery (TD) groups.

Results

A total of 1656 cervical mean SWE data were collected for analysis. Among the 138 twin pregnant women, only 92 women completed the three elastography examinations; PTD occurred in 58.7% (54/92), and TD in 41.3% (38/92). The mean (SD) maternal age was 33.1 ± 4.1 years, and the mean (SD) body mass index was 21.1 ± 2.6 kg/m². As gestational age increased, the mean SWE value of each part of the cervix decreased. The cervical mean SWE value was lower in the preterm group than in the term group in all three gestations, except for the anterior cervical lip at 28–32 weeks. Receiver operating characteristics (ROC) curves showed the sensitivity of mean SWE value of the anterior cervical lip was 83.3% (95% CI, 70.7–92.1) with a specificity of 57.9% (95% CI, 40.8–73.7) for predicting PTD at a cutoff value of 7.94 kPa. The positive likelihood ratio (LR+) was 1.67 (95% CI, 1.19–2.34), and the negative likelihood ratio (LR–) was 0.33 (95% CI, 0.17–0.64).

Conclusions

There is a significant negative correlation between cervical stiffness and gestational age in DCDA twin pregnancy. SWE is a potential tool for assessing cervical stiffness and predicting PTD in DCDA twin pregnancy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04526-0.