Relaxation time constant based optical coherence elastography

This study aimed at visualizing relative relaxation time constant (RTC) in soft tissue by using optical coherence elastography (OCE). We proposed a forced vibration model as a theoretical base to express RTC using axial gradient of periodic vibration phase captured by phase sensitive optical coherence tomography (PhS‐OCT). Validation of the model had been accomplished by experiments with isotropic and double‐layered phantoms. A fresh chicken breast sample treated with focused ultrasound was prepared to test performance of the RTC‐OCE in real tissue. All results were cross‐validated with indentation test and traditional strain‐based elastography. This study first utilized RTC mapping in 2D and 3D that covers the information of both elasticity and viscosity. The generated RTC mapping revealed the same mechanical difference internal sample which is correlated with conventional strain mapping. RTC mapping is potentially to be served as new biomarker for disease diagnosis in the future.     

The accuracy of needle electrode placement by trainees in selected forearm muscles using verification by neuromuscular ultrasound

IntroductionAnatomic landmarks alone may not always be sufficient to accurately guide electromyography (EMG) electrode needle placement.MethodsSenior residents and fellows (n = 11) targeted 4 forearm muscles with anatomic landmarks alone versus with audiovisual EMG feedback. Accuracy of EMG needle placement was verified using neuromuscular ultrasound imaging.ResultsWhile relatively large and superficial FCR muscle was sampled at a rate of 100% with and without audiovisual EMG feedback, accuracy of deeper and/or smaller forearm muscles (FPL, EIP, and SUP) diminished significantly without audiovisual EMG feedback.DiscussionOur study suggests that in clinical scenarios in which an electrodiagnostician relies on anatomic landmarks alone to target small and deep muscles, the risk of misplacement of needle electrode is increased. Consideration for neuromuscular ultrasound to augment training and/or real time guidance in EMG practice may be appropriate.     

Improving diagnostic strategies for ovarian cancer in Filipino women using ultrasound imaging and a multivariate index assay

ObjectiveTo evaluate the clinical performance and overall utility of imaging and biomarker assays in discriminating between benign and malignant ovarian masses in a Filipino population.MethodsThis is a prospective cohort study among Filipino women undergoing assessment for an ovarian mass in a tertiary center. All included patients underwent a physical examination before level III specialist ultrasonographic and Doppler evaluation, multivariate index assay (MIA2G), and surgery for an adnexal mass. Ovarian tumors were classified as high-risk for malignancy based on the International Ovarian Tumour Analysis (IOTA) – Logistic Regression 2 (LR2) score. The ovarian imaging and biomarker results were correlated with the reference standard: histological findings.ResultsAmong the 379 women with adnexal masses enrolled in this study, 291 were evaluable with ultrasound imaging, biomarker assays, and histopathological results. The risk of malignancy was higher for women classified as high-risk based on IOTA-LR2 (≥10%). The sensitivity, specificity, and diagnostic accuracy for the prediction of malignancy were 81.2%, 81%, and 0.81 (95% CI: 0.77–0.86) for IOTA-LR2; 77.5%, 66.7%, and 0.72 (95% CI: 0.67–0.77) for CA-125; and 91.3%, 41.2%, and 0.66 (95% CI: 0.62–0.71) for MIA2G. A combination of IOTA-LR2 and MIA2G significantly influenced the diagnostic performance and the result. When MIA2G was combined with IOTA-LR2 in parallel, the sensitivity (94.2%) and NPV (87.7%) increased, but the specificity (37.3%) decreased. When combined with IOTA-LR2 in series, there were fewer false positives, which resulted in improved specificity (85%).ConclusionThis study determined the utility of ovarian imaging and a second-generation multivariate index assay in predicting the risk of ovarian malignancy. IOTA-LR2 and MIA2G were useful in classifying patients with a high risk for ovarian malignancy.     

Rôle de l’échographie dans le diagnostic des kystes ovariens et des masses annexielles,en dehors de la grossesse et de la stimulation ovarienne

This article contains the semiological bases used to characterize ovarian lesions in imaging, especially ultrasound.     

Physical energy-based ultrasound shifts M1 macrophage differentiation towards M2 state

Recently, we read with interest the article entitled “Unveiling the Morphogenetic Code: A New Path at the Intersection of Physical Energies and Chemical Signaling”. In this paper, the investigation into the systematic and comprehensive bio-effects of physical energies prompted us to reflect on our research. We believe that ultrasound, which possesses a special physical energy, also has a certain positive regulatory effect on macrophages, and we have already obtained some preliminary research results that support our hypothesis.     

Synaptic inputs to the omega neuron of the cricket Teleogryllus oceanicus: differences in EPSP waveforms evoke by low and high sound frequencies

EPSP waveforms were recorded from the omega neuron of Teleogryllus oceanicus for 5 kHz and ultrasonic sound stimuli. EPSPs in response to 5 kHz stimuli were smooth in shape and increased in amplitude with increasing stimulus intensity, while responses to ultrasound consisted of series' of large, discrete, unitary EPSPs, which increased in frequency with stimulus intensity.The hypothesis that a few, synaptically potent receptors might account for ultrasound sensitivity was tested by examining temporal coupling between ultrasound responses of the omega neuron and of another ultrasound-sensitive neuron, INT-1. INT-1 spikes were temporally correlated both to omega neuron spikes and to the large EPSPs recorded in the omega neuron. Coupling was not apparent for 5 kHz stimuli.The omega neuron encodes the intensity of 5 kHz and ultrasonic stimuli with similar resolution. Response latencies are markedly shorter for ultrasonic stimuli.These findings suggest that 5 kHz information is carried by a relatively large number of receptors, each of which has only a small effect on central neurons, while ultrasound information is carried by a few, synaptically potent, receptors.