Transfer learning of pre-treatment quantitative ultrasound multi-parametric images for the prediction of breast cancer response to neoadjuvant chemotherapy.

Locally advanced breast cancer (LABC) is a severe type of cancer with a poor prognosis, despite advancements in therapy. As the disease is often inoperable, current guidelines suggest upfront aggressive neoadjuvant chemotherapy (NAC). Complete pathological response to chemotherapy is linked to improved survival, but conventional clinical assessments like physical exams, mammography, and imaging are limited in detecting early response.

Usefulness of computed tomography textural analysis in renal cell carcinoma nuclear grading.

To evaluate the usefulness of computed tomography (CT) texture descriptors integrated with machine-learning (ML) models in the identification of clear cell renal cell carcinoma (ccRCC) and for the first time papillary renal cell carcinoma (pRCC) tumor nuclear grades [World Health Organization (WHO)/International Society of Urologic Pathologists (ISUP) 1, 2, 3, and 4]. A total of 143 ccRCC and 21 pRCC patients were analyzed in this study. Texture features were extracted from late arterial phase CT images.

Marmoset brain segmentation from deconvolved magnetic resonance images and estimated label maps.

Purpose: The proposed method aims to create label maps that can be used for the segmentation of animal brain MR images without the need of a brain template. This is achieved by performing a joint deconvolution and segmentation of the brain MR images.

Methods: It is based on modeling locally the image statistics using a generalized Gaussian distribution (GGD) and couples the deconvolved image and its corresponding labels map using the GGD-Potts model.

Recent advances in medical image processing for the evaluation of chronic kidney disease.

Assessment of renal function and structure accurately remains essential in the diagnosis and prognosis of Chronic Kidney Disease (CKD). Advanced imaging, including Magnetic Resonance Imaging (MRI), Ultrasound Elastography (UE), Computed Tomography (CT) and scintigraphy (PET, SPECT) offers the opportunity to non-invasively retrieve structural, functional and molecular information that could detect changes in renal tissue properties and functionality. Currently, the ability of artificial intelligence to turn conventional medical imaging into a full-automated diagnostic tool is widely investigated.

Quantitative Ultrasound Imaging for the Differentiation between Fresh and Decellularized Mouse Kidneys.

Decellularization is a technique that permits the removal of cells from intact organs while preserving the extracellular matrix (ECM). It has many applications in various fields such as regenerative medicine and tissue engineering. This study aims to differentiate between fresh and decellularized kidneys using quantitative ultrasound (QUS) parameters.

Mean Scatterer Spacing Estimation Using Cepstrum-Based Continuous Wavelet Transform.

The goal of this study was to develop an ultrasound (US) scatterer spacing estimation method using an enhanced cepstral analysis based on continuous wavelet transforms (CWTs). Simulations of backscattering media containing periodic and quasi-periodic scatterers were carried out to test the developed algorithm. Experimental data from HT-29 pellets and in vivo PC3 tumors were then used to estimate the mean scatterer spacing.

Effect of filtering on the classification rate of nonlinear analysis methods applied to uterine EMG signals.

Nonlinear time series analysis can provide useful information regarding nonlinear features of biological signals. The effect of filtering on the performance of nonlinear methods is not well-understood. In this work, we investigate the effects of signal filtering on the sensitivity of four nonlinear methods: Time reversibility, Sample Entropy, Lyapunov Exponents and Delay Vector Variance.

Early detection of chemotherapy-refractory patients by monitoring textural alterations in diffuse optical spectroscopic images.

Purpose: Changes in textural characteristics of diffuse optical spectroscopic (DOS) functional images, accompanied by alterations in their mean values, are demonstrated here for the first time as early surrogates of ultimate treatment response in locally advanced breast cancer (LABC) patients receiving neoadjuvant chemotherapy (NAC). NAC, as a standard component of treatment for LABC patient, induces measurable heterogeneous changes in tumor metabolism which were evaluated using DOS-based metabolic maps. This study characterizes such inhomogeneous nature of response development, by determining alterations in textural properties of DOS images apparent at early stages of therapy, followed later by gross changes in mean values of these functional metabolic maps.

Quantitative evaluation of cell death response in vitro and in vivo using conventional-frequency ultrasound.

Previous studies using high-frequency ultrasound have suggested that radiofrequency (RF) spectral analysis can be used to quantify changes in cell morphology to detect cell death response to therapy non-invasively. The study here investigated this at conventional-frequencies, frequently used in clinical settings. Spectral analysis was performed using ultrasound RF data collected with a clinical ultrasound platform.

Assessment of tumor response to radiation and vascular targeting therapy in mice using quantitative ultrasound spectroscopy.

Purpose: It is now recognized that the tumor vasculature is in part responsible for regulating tumor responses to radiation therapy. However, the extent to which radiation-based vascular damage contributes to tumor cell death remains unknown. In this work, quantitative ultrasound spectroscopy (QUS) methods were used to investigate the acute responses of tumors to radiation-based vascular treatments.

Quantitative ultrasound spectroscopic imaging for characterization of disease extent in prostate cancer patients.

Three-dimensional quantitative ultrasound spectroscopic imaging of prostate was investigated clinically for the noninvasive detection and extent characterization of disease in cancer patients and compared to whole-mount, whole-gland histopathology of radical prostatectomy specimens. Fifteen patients with prostate cancer underwent a volumetric transrectal ultrasound scan before radical prostatectomy. Conventional-frequency (~5MHz) ultrasound images and radiofrequency data were collected from patients.

Low-frequency quantitative ultrasound imaging of cell death in vivo.

Purpose: Currently, no clinical imaging modality is used routinely to assess tumor response to cancer therapies within hours to days of the delivery of treatment. Here, the authors demonstrate the efficacy of ultrasound at a clinically relevant frequency to quantitatively detect changes in tumors in response to cancer therapies using preclinical mouse models.

Methods: Conventional low-frequency and corresponding high-frequency ultrasound (ranging from 4 to 28 MHz) were used along with quantitative spectroscopic and signal envelope statistical analyses on data obtained from xenograft tumors treated with chemotherapy, x-ray radiation, as well as a novel vascular targeting microbubble therapy.

Conventional frequency ultrasonic biomarkers of cancer treatment response in vivo.

Background: Conventional frequency quantitative ultrasound in conjunction with textural analysis techniques was investigated to monitor noninvasively the effects of cancer therapies in an in vivo preclinical model.

Methods: Conventional low-frequency (∼7 MHz) and high-frequency (∼20 MHz) ultrasound was used with spectral analysis, coupled with textural analysis on spectral parametric maps, obtained from xenograft tumor-bearing animals (n = 20) treated with chemotherapy to extract noninvasive biomarkers of treatment response.

Results: Results indicated statistically significant differences in quantitative ultrasound-based biomarkers in both low- and high-frequency ranges between untreated and treated tumors 12 to 24 hours after treatment.

Quantitative ultrasound evaluation of tumor cell death response in locally advanced breast cancer patients receiving chemotherapy.

Purpose: Quantitative ultrasound techniques have been recently shown to be capable of detecting cell death through studies conducted on in vitro and in vivo models. This study investigates for the first time the potential of early detection of tumor cell death in response to clinical cancer therapy administration in patients using quantitative ultrasound spectroscopic methods.

Experimental Design: Patients (n = 24) with locally advanced breast cancer received neoadjuvant chemotherapy treatments.

Evaluation of neoadjuvant chemotherapy response in women with locally advanced breast cancer using ultrasound elastography.

Purpose: Ultrasound elastography is a new imaging technique that can be used to assess tissue stiffness. The aim of this study was to investigate the potential of ultrasound elastography for monitoring treatment response of locally advanced breast cancer patients undergoing neoadjuvant therapy.

Methods: Fifteen women receiving neoadjuvant chemotherapy had the affected breast scanned before, 1, 4, and 8 weeks following therapy initiation, and then before surgery.

Diffuse optical imaging for monitoring treatment response in breast cancer patients.

The necessity for a non-invasive and inexpensive imaging modality to both diagnose and monitor treatment response has lead to renewed interest in the potential of optical imaging. The aim of this study was to investigate the potential of diffuse optical spectroscopy for monitoring of patients with locally advanced breast cancer undergoing neoadjuvant chemotherapy. Fifteen women receiving neoadjuvant treatment for breast cancer had the affected breast scanned 5 times: before, 1 week, 4 weeks, and 8 weeks following initiation of the treatment and prior to surgery.

Quantitative ultrasound spectral parametric maps: early surrogates of cancer treatment response.

Textural characteristics of quantitative ultrasound spectral parametric maps have been proposed for the first time to predict cancer therapy response, early following treatment initiation. Such an early prediction can facilitate personalized medicine in cancer treatment procedures. Patients (n=10) with locally advanced breast cancer received neo-adjuvant chemotherapy, as "up-front" treatment, followed by mastectomy with axillary nodal clearance.

Quantitative ultrasound visualization of cell death: emerging clinical applications for detection of cancer treatment response.

Differentiable echogeneities exhibited by living and dead cells enables the monitoring of cell death response via quantitative ultrasound techniques at high-frequencies and recently at clinical range frequencies. Such capability can be potentially employed to provide rapid and quantitative functional information in real time, and at the patient bedside for evaluating therapy response early following treatment. This paper summarizes backgrounds on quantitative ultrasound visualization of cell death and highlights its potential capabilities for monitoring cancer treatment response, where favorable results have been reported, according to a recent pilot clinical study.

Surface modes and acoustic scattering of microspheres and ultrasound contrast agents.

Surface modes of spherical objects subject to ultrasound excitation have been recently proposed to explain experimental measurements of scattering from microspheres and ultrasound contrast agents (UCAs). In this work, the relationship between surface modes and resonance frequencies of microspheres and UCAs is investigated. A finite-element model, built upon the fundamentals of wave propagation and structural mechanics, was introduced and validated against analytical solutions (error <5%).

Diffuse optical spectroscopy evaluation of treatment response in women with locally advanced breast cancer receiving neoadjuvant chemotherapy.

The aim of this study was to investigate the potential of diffuse optical spectroscopy for monitoring of patients with locally advanced breast cancer (LABC) undergoing neoadjuvant chemotherapy. Fifteen women receiving treatment for LABC had the affected breast scanned before; 1 week, 4 weeks, and 8 weeks after treatment initiation; and before surgery. Optical properties related to tissue microstructure and biochemical composition were obtained.

The measurement of ultrasound scattering from individual micron-sized objects and its application in single cell scattering.

The measurement of the ultrasound backscatter from individual micron-sized objects such as cells is required for various applications such as tissue characterization. However, performing such a measurement remains a challenge. For example, the presence of air bubbles in a suspension of cells during the measurements may lead to the incorrect interpretation of the acoustic signals.

A study of high frequency ultrasound scattering from non-nucleated biological specimens.

The high frequency backscatter from cells with a nucleus to cell volume ratio of 0.50 cannot be adequately modeled as a homogeneous sphere. It was hypothesized that the cytoplasm of such cells is of fluid nature.