Quantitative Ultrasound Parameters Research Articles

High-frequency quantitative ultrasound to assess chemical crosslinking induced changes in the posterior sclera

Myopia alters the collagen microstructure of the sclera which changes the tissue biomechanical properties. Although most forms of myopia are mild, progression of the disease to high or pathologic myopia can lead to significant weakening of the sclera and greatly increase the risk for the formation of a posterior staphyloma, a sight-threatening condition. Potential treatments to counteract effects of myopia on the sclera include chemical crosslinking (CXL). Formaldehyde releasing agents like sodium hydroxymethylglycinate (SHMG) are an attractive option for the posterior sclera because they increase tissue stiffness and require no light activation. Previous research has demonstrated that high-frequency quantitative ultrasound (QUS) is sensitive to the microstructural changes in the sclera caused by myopia. In this study, we investigate the ability of QUS to monitor microstructural changes caused by CXL. Ex vivo pig eyes were immersed in a 26.5 mM SHMG solution and scanned by an 80MHz ultrasound transducer at regular time intervals. RF echo data were analyzed to compute QUS parameters from the backscatter coefficient, normalized power spectrum, and echo envelope statistics. Correlations between QUS parameters and immersion time were investigated to evaluate the efficacy of QUS for monitoring CXL treatment. Results of this study demonstrate the capability to high-frequency QUS to assess changes in tissue microstructure caused by CXL with SHMG.

Contribution of peripheral neuropathy to poor bone health in the feet of people with type 2 diabetes mellitus.

AimsTo evaluate the impact of peripheral neuropathy on bone health in people with type 2 diabetes mellitus (T2DM).MethodsParticipants with T2DM were grouped according to the presence of peripheral neuropathy as assessed by vibration perception threshold (VPT). Recruitment ensured groups were balanced for age, sex and body mass index (BMI). Bone health was measured by calcaneal quantitative ultrasound (QUS) and compared between groups. Calcaneal QUS parameters were correlated across the cohort with VPT and other prespecified variables. ResultsThirty-four participants (17 per group) were included with mean age 68 ± 12 years, 47% male, with median BMI 29.9 (IQR 26.9–32.7) kg/m2. The peripheral neuropathy group had significantly lower mean Stiffness Index (87 ± 12 versus 101 ± 16, p = 0.01), Speed of Sound (1542 ± 28 versus 1574 ± 34 m/s, p < 0.01), and a trend towards lower Broadband Ultrasound Attenuation (113 ± 10 versus 120 ± 12 dB/MHz, p = 0.07). Pedal bone health asymmetry was not a significant feature in those with peripheral neuropathy. All calcaneal QUS parameters correlated negatively with VPT, although significance of the relationship with Broadband Ultrasound Attenuation was nullified if controlled for diabetes duration or time on insulin. Broadband Ultrasound Attenuation showed independent negative correlation with diabetes duration.ConclusionsPeople with T2DM and peripheral neuropathy have poorer bone health as measured by calcaneal QUS than those without peripheral neuropathy, independent of age, sex and BMI.

Non-Invasive Ultrasonic Description of Tumor Evolution.

Simple SummaryDuring tumor evolution, heterogeneous structural and functional changes occur in the tumor microenvironment. These complex changes have pro- or anti-tumorigenesis effects and have an impact on therapy efficiency. Therefore, the tumor microenvironment needs to be non-invasively characterized over time. The aim of this preclinical work is to compare the sensitivity of modifications occurring during tumor evolution of volume, immunohistochemistry and non-invasive quantitative ultrasound parameters (Shear Wave Elastography and dynamic Contrast-Enhanced Ultrasound) and to study the link between them. The complementary evaluation over time of multiple morphological and functional parameters during tumor growth underlines the need to integrate histological, morphological, functional, and, ultimately, genomic information into models that can consider the temporal and spatial variability of features to better understand tumor evolution.Purpose: There is a clinical need to better non-invasively characterize the tumor microenvironment in order to reveal evidence of early tumor response to therapy and to better understand therapeutic response. The goals of this work are first to compare the sensitivity to modifications occurring during tumor growth for measurements of tumor volume, immunohistochemistry parameters, and emerging ultrasound parameters (Shear Wave Elastography (SWE) and dynamic Contrast-Enhanced Ultrasound (CEUS)), and secondly, to study the link between the different parameters. Methods: Five different groups of 9 to 10 BALB/c female mice with subcutaneous CT26 tumors were imaged using B-mode morphological imaging, SWE, and CEUS at different dates. Whole-slice immunohistological data stained for the nuclei, T lymphocytes, apoptosis, and vascular endothelium from these tumors were analyzed. Results: Tumor volume and three CEUS parameters (Time to Peak, Wash-In Rate, and Wash-Out Rate) significantly changed over time. The immunohistological parameters, CEUS parameters, and SWE parameters showed intracorrelation. Four immunohistological parameters (the number of T lymphocytes per mm2 and its standard deviation, the percentage area of apoptosis, and the colocalization of apoptosis and vascular endothelium) were correlated with the CEUS parameters (Time to Peak, Wash-In Rate, Wash-Out Rate, and Mean Transit Time). The SWE parameters were not correlated with the CEUS parameters nor with the immunohistological parameters. Conclusions: US imaging can provide additional information on tumoral changes. This could help to better explore the effect of therapies on tumor evolution, by studying the evolution of the parameters over time and by studying their correlations.

Association between vitamin D and bone mineral density in Japanese adults: the Unzen study.

The primary objective of this study was to examine the correlation between serum 25-hydroxyvitamin D (25(OH)D) concentration and bone indicators as measured by quantitative ultrasound in middle-aged and older Japanese adults living in low-latitude seaside areas during summer and autumn. We conducted a cross-sectional study, the Unzen study, on community-dwelling Japanese adults who participated to periodic health examinations between 2011 and 2013 (during the months of May to November). A total of 301 men (mean (SD) age, 67.9 (8.2) years; range, 50-92years) and 429 women (mean (SD) age, 67.9 (7.7); range, 50-89years) participated in this study. Serum 25(OH)D levels and quantitative ultrasound parameters (broadband ultrasound (BUA), speed of sound (SOS), and stiffness index of the calcaneus were measured for the participants. We excluded two men and 28 women from the 730 participants because they were on medication for osteoporosis. So, 299 men and 401 women were included in the final data analysis. The prevalence of vitamin D insufficiency (< 30ng/ml) was very high: 71.9% in men and 95.5% in women. In women, the log(25(OH)D) positively and significantly correlated with SOS (p = 0.011) and stiffness index (p = 0.028) but not with BUA (p = 0.176). In men, the log(25(OH)D) did not correlate with the BUA, SOS, or stiffness index (p = 0.218, 0.420, and 0.262, respectively). Serum 25(OH)D levels were associated with SOS or stiffness index in women but not in men.

In vivo assessment of prostate cancer response using quantitative ultrasound characterization of ultrasonic scattering properties

BackgroundThe study here investigated quantitative ultrasound (QUS) parameters to assess tumour response to ultrasound-stimulated microbubbles (USMB) and hyperthermia (HT) treatment in vivo. Mice bearing prostate cancer xenografts were exposed to various treatment conditions including 1% (v/v) Definity microbubbles stimulated at ultrasound pressures 246 kPa and 570 kPa and HT duration of 0, 10, 40, and 50 min. Ultrasound radiofrequency (RF) data were collected using an ultrasound transducer with a central frequency of 25 MHz. QUS parameters based on form factor models were used as potential biomarkers of cell death in prostate cancer xenografts.ResultsThe average acoustic concentration (AAC) parameter from spherical gaussian and the fluid-filled spherical models were the most efficient imaging biomarker of cell death. Statistical significant increases of AAC were found in the combined treatment groups: 246 kPa + 40 min, 246 kPa + 50 min, and 570 kPa + 50 min, in comparison with control tumours (0 kPa + 0 min). Changes in AAC correlates strongly (r2 = 0.62) with cell death fraction quantified from the histopathological analysis.ConclusionScattering property estimates from spherical gaussian and fluid-filled spherical models are useful imaging biomarkers for assessing tumour response to treatment. Our observation of changes in AAC from high ultrasound frequencies was consistent with previous findings where parameters related to the backscatter intensity (AAC) increased with cell death.

Quantitative Evaluation of Renal Cortex Perfusion Using Contrast-Enhanced Ultrasound Imaging Parameters in Ischemia–Reperfusion Injury in Rabbits

The aim of this study was to evaluate blood perfusion of the renal cortex during ischemia–reperfusion (I/R) injury using quantitative contrast-enhanced ultrasound (CEUS) parameters. In this experiment, 24 rabbits were randomly divided into four groups (N = 6): sham-operated group, 24-h post-operation for I/R injury group (24-h I/R), 3-d post-operation for I/R injury group (3-d I/R) and 5 d post-operation for I/R injury group (5 d I/R). All quantitative CEUS parameters were monitored and included the gradient from the start frame to the peak frame (Grad), area under the curve (Area), time-to-peak (TTP), difference between B(intercept intensity at t=0) and A(the intensity attenuation t= 0) and arrival time (AT). Subsequently, we analyzed the changes in these parameters, as well as the correlation between changes in CEUS parameters and pathological parameters. AT and TTP values peaked 3 d after I/R surgery, which correlated with the most significant pathological changes at the same time point. These parameters (such as AT, TTP and Grad) may be useful in dynamically monitoring the severity of tissue damage at the early stage of I/R injury.

In vivo pulse-echo measurement of apparent broadband attenuation and Q factor in cortical bone: a preliminary study

Quantitative ultrasound (QUS) methods have been introduced to assess cortical bone health at the radius and tibia through the assessment of cortical thickness (Ct.Th), cortical porosity and bulk wave velocities. Ultrasonic attenuation is another QUS parameter which is not currently used. We assessed the feasibility of in vivo measurement of ultrasonic attenuation in cortical bone with a broadband transducer with 3.5 MHz center frequency. Echoes from the periosteal and endosteal interfaces were fitted with Gaussian pulses using sparse signal processing. Then, the slope of the broadband ultrasonic attenuation (Ct.nBUA) in cortical bone and quality factor were calculated with a parametric approach based on the center-frequency shift. Five human subjects were measured at the one-third distal radius with pulse-echo ultrasound, and reference data was obtained with high-resolution x-ray peripheral computed tomography (Ct.Th and cortical volumetric bone mineral density (Ct.vBMD)). Ct.Th was used in the calculation of Ct.nBUA while is obtained solely from ultrasound data. The values of Ct.nBUA (6.7 ± 2.2 dB MHz−1 .cm−1) and (8.6 ± 3.1%) were consistent with the literature data and were correlated to Ct.vBMD (, , RMSE = 0.56 dB.MHz−1.cm−1, and , , RMSE = 0.76%). This preliminary study suggests that the attenuation of an ultrasound signal propagating in cortical bone can be measured in vivo at the one-third distal radius and that it provides an information on bone quality as attenuation values were correlated to Ct.vBMD. It remains to ascertain that Ct.nBUA and measured here exactly reflect the true (intrinsic) ultrasonic attenuation in cortical bone. Measurement of attenuation may be considered useful for assessing bone health combined with the measurement of Ct.Th, porosity and bulk wave velocities in multimodal cortical bone QUS methods.

Diagnostic Performance of 9 Quantitative Ultrasound Parameters for Detection and Classification of Hepatic Steatosis in Nonalcoholic Fatty Liver Disease.

Nonalcoholic fatty liver disease (NAFLD) is a leading cause of chronic liver disease worldwide. Quantitative ultrasound (QUS) parameters based on radiofrequency raw data show promise in quantifying liver fat. The aim of this study was to evaluate the diagnostic performance of 9 QUS parameters compared with magnetic resonance imaging (MRI)-estimated proton density fat fraction (PDFF) in detecting and staging hepatic steatosis in patients with or suspected of NAFLD. In this Health Insurance Portability and Accountability Act-compliant institutional review board-approved prospective study, 31 participants with or suspected of NAFLD, without other underlying chronic liver diseases (13 men, 18 women; average age, 52 years [range, 26-90 years]), were examined. The following parameters were obtained: acoustic attenuation coefficient (AC); hepatorenal index (HRI); Nakagami parameter; shear wave elastography measures such as shear wave elasticity, viscosity, and dispersion; and spectroscopy-derived parameters including spectral intercept (SI), spectral slope (SS), and midband fit (MBF). The diagnostic ability (area under the receiver operating characteristic curves and accuracy) of QUS parameters was assessed against different MRI-PDFF cutoffs (the reference standard): 6.4%, 17.4%, and 22.1%. Linearity with MRI-PDFF was evaluated with Spearman correlation coefficients (p). The AC, SI, Nakagami, SS, HRI, and MBF strongly correlated with MRI-PDFF (P = 0.89, 0.89, 0.88, -0.87, 0.81, and 0.71, respectively [P < 0.01]), with highest area under the receiver operating characteristic curves (ranging from 0.85 to 1) for identifying hepatic steatosis using 6.4%, 17.4%, and 22.1% MRI-PDFF cutoffs. In contrast, shear wave elasticity, shear wave viscosity, and shear wave dispersion did not strongly correlate to MRI-PDFF (P = 0.45, 0.38, and 0.07, respectively) and had poor diagnostic performance. The AC, Nakagami, SI, SS, MBF, and HRI best correlate with MRI-PDFF and show high diagnostic performance for detecting and classifying hepatic steatosis in our study population. Quantitative ultrasound is an accurate alternative to MRI-based techniques for evaluating hepatic steatosis in patients with or at risk of NAFLD. Our preliminary results show that specific quantitative ultrasound parameters accurately detect different degrees of hepatic steatosis in NAFLD.

Computational Modeling of Ultrasound C-Scan Imaging Using Transmitted Signal Peak Density

Ultrasound measurement is a relatively inexpensive and commonly used imaging tool in the health sector. The through-transmission process of ultrasound measurement has been extensively evaluated for detecting abnormalities in tissue pathology. Compared to standard imaging parameters such as amplitude and time of flight, quantitative ultrasound parameters in the frequency domain can provide additional details regarding tissue microstructures. In this study, pressure magnitude or amplitude variation in the frequency spectrum of the received signal was evaluated as a potential imaging technique using the spectral peak density parameter. Computational C-scan imaging analysis was developed through a finite element model. The magnitude variation in the received signal showed different patterns while interacting with and without inclusions. Images were reconstructed based on peak density values that varied with the presence of solid structure. The computational results were verified with the experimental C-scan imaging results from the literature. It was found that magnitude variation can be an effective parameter for C-scan imaging of thin structures. The feasibility of the study was further extended to identify the structure’s relative position along with the sample depth during C-scan imaging. While moving the structure in the direction of the sample depth, the pressure magnitude variation strongly followed a second-degree polynomial trend.

A Preliminary Study of Quantitative Ultrasound for Cancer-Risk Assessment of Thyroid Nodules.

BackgroundGray-scale, B-mode ultrasound (US) imaging is part of the standard clinical procedure for evaluating thyroid nodules (TNs). It is limited by its instrument- and operator-dependence and inter-observer variability. In addition, the accepted high-risk B-mode US TN features are more specific for detecting classic papillary thyroid cancer rather than the follicular variant of papillary thyroid cancer or follicular thyroid cancer. Quantitative ultrasound (QUS) is a technique that can non-invasively assess properties of tissue microarchitecture by exploiting information contained in raw ultrasonic radiofrequency (RF) echo signals that is discarded in conventional B-mode imaging. QUS provides quantitative parameter-value estimates that are a function of the properties of US scatterers and microarchitecture of the tissue. The purpose of this preliminary study was to assess the performance of QUS parameters in evaluating benign and malignant thyroid nodules.MethodsPatients from the Thyroid Health Center at the Boston Medical Center were recruited to participate. B-mode and RF data were acquired and analyzed in 225 TNs (24 malignant and 201 benign) from 208 patients. These data were acquired either before (167 nodules) or after (58 nodules) subjects underwent fine-needle biopsy (FNB). The performance of a combination of QUS parameters (CQP) was assessed and compared with the performance of B-mode risk-stratification systems.ResultsCQP produced an ROC AUC value of 0.857 ± 0.033 compared to a value of 0.887 ± 0.033 (p=0.327) for the American College of Radiology Thyroid Imaging, Reporting and Data System (ACR TI-RADS) and 0.880 ± 0.041 (p=0.367) for the American Thyroid Association (ATA) risk-stratification system. Furthermore, using a CQP threshold of 0.263 would further reduce the number of unnecessary FNBs in 44% of TNs without missing any malignant TNs. When CQP used in combination with ACR TI-RADS, a potential additional reduction of 49 to 66% in unnecessary FNBs was demonstrated.ConclusionThis preliminary study suggests that QUS may provide a method to classify TNs when used by itself or when combined with a conventional gray-scale US risk-stratification system and can potentially reduce the need to biopsy TNs.

Analytic Global Regularized Backscatter Quantitative Ultrasound.

Although a variety of techniques have been developed to reduce the appearance of B-mode speckle, quantitative ultrasound (QUS) aims at extracting the hidden properties of the tissue. Herein, we propose two novel techniques to accurately and precisely estimate two important QUS parameters, namely, the average attenuation coefficient and the backscatter coefficient. Both the techniques optimize a cost function that incorporates data and continuity constraint terms, which we call AnaLytical Global rEgularized BackscatteR quAntitative ultrasound (ALGEBRA). We propose two versions of ALGEBRA, namely, 1-D- and 2-D-ALGEBRA. In 1-D-ALGEBRA, the regularized cost function is formulated in the axial direction, and the QUS parameters are calculated for one line of radio frequency (RF) echo data. In 2-D-ALGEBRA, the regularized cost function is formulated for the entire image, and the QUS parameters throughout the image are estimated simultaneously. This simultaneous optimization allows 2-D-ALGEBRA to "see" all the data before estimating the QUS parameters. In both the methods, we efficiently optimize the cost functions by casting it as a sparse linear system of equations. As a result of this efficient optimization, 1-D-ALGEBRA and 2-D-ALGEBRA are, respectively, 600 and 300 times faster than optimization using the dynamic programming (DP) method previously proposed by our group. In addition, the proposed technique has fewer input parameters that require manual tuning. Our results demonstrate that the proposed ALGEBRA methods substantially outperform least-square and DP methods in estimating the QUS parameters in phantom experiments.

Ultrasonographic profile of non-alcoholic fatty liver disease manifestation in patients with hypertension

Objective — to determine the features of liver ultrasonographic parameters in patients with combination of non‑alcoholic fatty liver disease (NAFLD) and hypertension (HT).&#x0D; Materials and methods. The investigation involved 115 patients with NAFLD at the stage of non‑alcoholic steatohepatitis. The main group (n = 63) consisted of patients with comorbid NAFLD and HT, the comparison group (n = 52) included patients with isolated NAFLD, and the control group consisted of 20 apparently healthy individuals. Based on the results of clinical and laboratory tests, indices of the degree of liver fibrosis were calculated: Fibrosis‑4 (FIB‑4) and NAFLD fibrosis score (NFS). A comprehensive assessment of ultrasonographic signs of liver and surrounding organs damage and a semi‑quantitative assessment of liver steatosis according to the Ultrasound fatty liver indicator (US‑FLI) scale was performed during ultrasound examinations.&#x0D; Results. Among the main ultrasound signs of steatosis, a significant liver size increase, liver parenchyma hyperechogenicity, changes in the vascular pattern, a hepatic portal system overload were found in all patients with NAFLD and HT. The average US‑FLI test result in the group with comorbid NAFLD and HT was 6 points (95 % CI 5.24; 6.12). This value was significantly higher compared to the group with isolated NAFLD, where the results averaged 3 points (95 % CI 2.91; 3.74; p &lt; 0.001). FIB‑4 and NFS indices were also significantly higher in patients with NAFLD and HT. An increased risk of liver fibrosis was found in patients with comorbidity of NAFLD and HT. The significant effects of concomitant HT on the progression of fibrotic changes in the liver parenchyma in NAFLD have been determined.&#x0D; Conclusions. Concomitant HT in patients with NAFLD introduces deviations in the ultrasonographic profile of the liver. It is manifested by a significantly more frequent detection of the main signs of steatosis, more expressive changes in quantitative ultrasound parameters and qualitative signs of liver steatosis according to the US‑FLI test. The non‑invasive fibrosis tests results indicate an intensification of fibrosis processes in the liver parenchyma in patients with NAFLD and HT. The obtained data allow us to consider HT as a trigger factor for the progression of liver fibrotic changes in patients with NAFLD.&#x0D;

Vegan Diet and Bone Health-Results from the Cross-Sectional RBVD Study.

Scientific evidence suggests that a vegan diet might be associated with impaired bone health. Therefore, a cross-sectional study (n = 36 vegans, n = 36 omnivores) was used to investigate the associations of veganism with calcaneal quantitative ultrasound (QUS) measurements, along with the investigation of differences in the concentrations of nutrition- and bone-related biomarkers between vegans and omnivores. This study revealed lower levels in the QUS parameters in vegans compared to omnivores, e.g., broadband ultrasound attenuation (vegans: 111.8 ± 10.7 dB/MHz, omnivores: 118.0 ± 10.8 dB/MHz, p = 0.02). Vegans had lower levels of vitamin A, B2, lysine, zinc, selenoprotein P, n-3 fatty acids, urinary iodine, and calcium levels, while the concentrations of vitamin K1, folate, and glutamine were higher in vegans compared to omnivores. Applying a reduced rank regression, 12 out of the 28 biomarkers were identified to contribute most to bone health, i.e., lysine, urinary iodine, thyroid-stimulating hormone, selenoprotein P, vitamin A, leucine, α-klotho, n-3 fatty acids, urinary calcium/magnesium, vitamin B6, and FGF23. All QUS parameters increased across the tertiles of the pattern score. The study provides evidence of lower bone health in vegans compared to omnivores, additionally revealing a combination of nutrition-related biomarkers, which may contribute to bone health. Further studies are needed to confirm these findings.

Liver Fat Quantification by Ultrasound in Children: A Prospective Study.

BACKGROUND. Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in children in certain regions and is rising in prevalence with increasing obesity. Accurate noninvasive imaging methods for diagnosing and quantifying liver fat are needed to guide NAFLD management. OBJECTIVE. The purpose of this article is to evaluate four ultrasound technologies for quantitative assessment of liver fat content in children using MRI proton density fat fraction (PDFF) as a reference standard. METHODS. This prospective study enrolled children who underwent clinical abdominal MRI without general anesthesia between November 2018 and July 2019. Patients underwent investigational liver ultrasound within a day of 1.5-T or 3-T MRI. Acquired ultrasound radiofrequency data were processed offline to compute the acoustic attenuation coefficient, hepatorenal index (HRI), Nakagami parameter, and shear-wave elastography (SWE) parameters (elasticity, viscosity, and dispersion). Ultrasound parameters were compared with MRI PDFF obtained using a multiecho sequence. A second observer independently performed offline attenuation coefficient and HRI measurements in all patients. RESULTS. A total of 48 patients were enrolled: 22 girls, 26 boys; mean age of 13 years (range, 7-17 years); mean body mass index (weight in kilograms divided by the square of height in meters) of 22.25 (range, 14.5-48.1). A total of 21% (10/48) had steatosis (PDFF ≥ 5%). PDFF was correlated with attenuation coefficient (r = 0.76; 95% CI, 0.60-0.86; p < .001), HRI (r = 0.84; 95% CI, 0.74-0.91; p < .001), and Nakagami parameter (r = 0.55, 95% CI, 0.32-0.72, p < .001), but not SWE parameters (r = 0.05-0.25; p > .05). In patients with no, mild, moderate, and severe steatosis according to PDFF, the mean (± SD) attenuation coefficient was 0.48 ± 0.08, 0.54 ± 0.03, 0.57 ± 0.04, and 0.86 ± 0.07 dB/cm/MHz, respectively, and the mean HRI was 1.28 ± 0.30, 1.59 ± 0.23, 2.25 ± 0.04, and 3.06 ± 0.49, respectively. For the attenuation coefficient, the threshold of 0.54 dB/cm/MHz achieved a sensitivity of 80% and a specificity of 82% for steatosis, and 0.60 dB/cm/MHz achieved a sensitivity of 80% and a specificity of 98% for moderate steatosis. For HRI, the threshold of 1.48 achieved sensitivity of 90% and specificity of 76% for steatosis, and 2.11 achieved sensitivity of 100% and specificity of 100% for moderate steatosis. The interobserver concordance coefficient was 0.92 for attenuation coefficient and 0.91 for HRI. CONCLUSION. Attenuation coefficient and HRI accurately detected and quantified liver fat in this small sample of children. CLINICAL IMPACT. Quantitative ultrasound parameters may guide NAFLD diagnosis and management in children.

Quantitative Ultrasound of the Heel in Women With Knee Osteoarthritis

The prevalence of multiple falls is higher in older women, and knee pain is associated with multiple falls in women; thus, it is important to detect individuals at risk of fractures among women with knee osteoarthritis. We aimed to clarify the association between knee osteoarthritis and the quantitative ultrasound (QUS) parameter, and investigate the clinical relevance of the QUS parameter with osteoarthritis-related characteristics in women with knee osteoarthritis. This was a cross-sectional study. We recruited 101 women with knee osteoarthritis at a local orthopedic hospital and 102 healthy individuals from the community. Heel QUS measurements were performed using the QUS device, measuring the stiffness index. We also assessed knee pain, quadriceps strength, and physical activity in women with knee osteoarthritis. We fitted a multiple regression model to estimate the association between knee osteoarthritis and the stiffness index. We also fitted 3 multiple regression models to investigate the clinical relevance of the QUS parameter with osteoarthritis-related characteristics in women with knee osteoarthritis. Compared with the control group, individuals with grade 2 osteoarthritis did not demonstrate a significant difference in stiffness index (p = 0.68); however, those with grade 3 osteoarthritis (p < 0.001) and 4 (p < 0.001) showed a lower stiffness index than that of the control group. Additionally, although the QUS parameter did not show an association with knee pain score (p = 0.70) or quadriceps strength (p = 0.11), we found a significant association between the QUS parameter and physical activity (p = 0.003). Our results demonstrate that women with moderate or severe knee osteoarthritis showed lower QUS parameters compared to healthy women, and the QUS parameter was associated with physical activity in women with knee osteoarthritis.

Quantitative Ultrasound Radiofrequency Data Analysis for the Assessment of Hepatic Steatosis in Nonalcoholic Fatty Liver Disease Using Magnetic Resonance Imaging Proton Density Fat Fraction as the Reference Standard.

ObjectiveTo investigate the diagnostic performance of quantitative ultrasound (US) parameters for the assessment of hepatic steatosis in patients with nonalcoholic fatty liver disease (NAFLD) using magnetic resonance imaging proton density fat fraction (MRI-PDFF) as the reference standard.Materials and MethodsIn this single-center prospective study, 120 patients with clinically suspected NAFLD were enrolled between March 2019 and January 2020. The participants underwent US examination for radiofrequency (RF) data acquisition and chemical shift-encoded liver MRI for PDFF measurement. Using the RF data analysis, the attenuation coefficient (AC) based on tissue attenuation imaging (TAI) (AC-TAI) and scatter-distribution coefficient (SC) based on tissue scatter-distribution imaging (TSI) (SC-TSI) were measured. The correlations between the quantitative US parameters (AC and SC) and MRI-PDFF were evaluated using Pearson correlation coefficients. The diagnostic performance of AC-TAI and SC-TSI for detecting hepatic fat contents of ≥ 5% (MRI-PDFF ≥ 5%) and ≥ 10% (MRI-PDFF ≥ 10%) were assessed using receiver operating characteristic (ROC) analysis. The significant clinical or imaging factors associated with AC and SC were analyzed using linear regression analysis.ResultsThe participants were classified based on MRI-PDFF: < 5% (n = 38), 5–10% (n = 23), and ≥ 10% (n = 59). AC-TAI and SC-TSI were significantly correlated with MRI-PDFF (r = 0.659 and 0.727, p < 0.001 for both). For detecting hepatic fat contents of ≥ 5% and ≥ 10%, the areas under the ROC curves of AC-TAI were 0.861 (95% confidence interval [CI]: 0.786–0.918) and 0.835 (95% CI: 0.757–0.897), and those of SC-TSI were 0.964 (95% CI: 0.913–0.989) and 0.935 (95% CI: 0.875–0.972), respectively. Multivariable linear regression analysis showed that MRI-PDFF was an independent determinant of AC-TAI and SC-TSI.ConclusionAC-TAI and SC-TSI derived from quantitative US RF data analysis yielded a good correlation with MRI-PDFF and provided good performance for detecting hepatic steatosis and assessing its severity in NAFLD.

Use of a convolutional neural network and quantitative ultrasound for diagnosis of fatty liver

Quantitative ultrasound (QUS) was used to classify rabbits that were induced to have liver disease by placing them on a fatty diet for a defined duration and/or periodically injecting them with CCl4. The ground truth of the liver state was based on lipid liver percents estimated via the Folch assay and hydroxyproline concentration to quantify fibrosis. Rabbits were scanned ultrasonically in vivo using a SonixOne scanner and an L9-4/38 linear array. Liver fat percentage was classified based on the ultrasonic backscattered radiofrequency (RF) signals from the livers using either QUS or a 1-D convolutional neural network (CNN). Use of QUS parameters with linear regression and canonical correlation analysis demonstrated that the QUS parameters could differentiate between livers with lipid levels above or below 5%. However, the QUS parameters were not sensitive to fibrosis. The CNN was implemented by analyzing raw RF ultrasound signals without using separate reference data. The CNN outputs the classification of liver as either above or below a threshold of 5% fat level in the liver. The CNN outperformed the classification utilizing the QUS parameters combined with a support vector machine in differentiating between low and high lipid liver levels (i.e., accuracies of 74% versus 59% on the testing data). Therefore, although the CNN did not provide a physical interpretation of the tissue properties (e.g., attenuation of the medium or scatterer properties) the CNN had much higher accuracy in predicting fatty liver state and did not require an external reference scan.

Quantitative ultrasound radiomics in predicting recurrence for patients with node-positive head-neck squamous cell carcinoma treated with radical radiotherapy.

This prospective study was conducted to investigate the role of quantitative ultrasound (QUS) radiomics in predicting recurrence for patients with node‐positive head‐neck squamous cell carcinoma (HNSCC) treated with radical radiotherapy (RT). The most prominent cervical lymph node (LN) was scanned with a clinical ultrasound device having central frequency of 6.5 MHz. Ultrasound radiofrequency data were processed to obtain 7 QUS parameters. Color‐coded parametric maps were generated based on individual QUS spectral features corresponding to each of the smaller units. A total of 31 (7 primary QUS and 24 texture) features were obtained before treatment. All patients were treated with radical RT and followed according to standard institutional practice. Recurrence (local, regional, or distant) served as an endpoint. Three different machine learning classifiers with a set of maximally three features were used for model development and tested with leave‐one‐out cross‐validation for nonrecurrence and recurrence groups. Fifty‐one patients were included, with a median follow up of 38 months (range 7–64 months). Recurrence was observed in 17 patients. The best results were obtained using a k‐nearest neighbor (KNN) classifier with a sensitivity, specificity, accuracy, and an area under curve of 76%, 71%, 75%, and 0.74, respectively. All the three features selected for the KNN model were texture features. The KNN‐model‐predicted 3‐year recurrence‐free survival was 81% and 40% in the predicted no‐recurrence and predicted‐recurrence groups, respectively. (p = 0.001). The pilot study demonstrates pretreatment QUS‐radiomics can predict the recurrence group with an accuracy of 75% in patients with node‐positive HNSCC.Clinical trial registration: clinicaltrials.gov.in identifier NCT03908684.

A high-fat diet in the presence of vitamin D deficiency status is associated with a negative influence on calcaneal quantitative ultrasound parameters in young adults: a cross-sectional study

Vitamin D deficiency and a high-fat diet are considered health problems worldwide. The aims of this study were to examine the prevalence of vitamin D deficiency/insufficiency in young adults, factors related to the vitamin D status, and the influence of vitamin D deficiency and/or a high-fat diet on bone parameters. Here, we investigated the hypothesis that a high-fat diet in the presence of a vitamin D-deficient status would have a more negative influence on bone parameters than a normal-fat diet with such a status. In the present study, we targeted young Japanese adults aged 21-23 (n = 175). We conducted a diet survey based on 3-day food records, biochemical examination of serum, and quantitative ultrasound measurements at the calcaneus. As a result, the rates of vitamin D deficiency {serum 25-hydroxyvitamin D3 [25(OH)D] concentration less than 20 ng/mL} and insufficiency [serum 25(OH)D concentration less than 30 ng/mL but not less than 20 ng/mL] were 60.6 and 30.9%, respectively. A positive correlation was observed between the serum 25(OH)D level and serum bone-specific alkaline phosphatase level, which is a serum marker of bone formation (r = 0.253, P< .01) or the speed of sound (SOS) as an index of bone density (r = 0.259, P< .01). A negative correlation was observed between the ratio of fat intake to total energy intake (%E) and serum 25(OH)D levels (r = −0.206, P< .01). Furthermore, we revealed that a high-fat diet in the presence of a vitamin D deficient status reduced the SOS parameter compared with a normal-fat diet with a vitamin D-deficient status (P< .05).

The Correlation between Phalangeal Quantitative Ultrasonography and Dual Energy X-ray Absorptiometry in Women with Premature Ovarian Failure

With the growing demand for bone densitometry services there is a need for simple, cost-effective and ideally mobile devices which can identify individuals who are at risk of osteoporotic fracture. When new devices are evaluated, it is useful to examine the correlation with the established 'gold standard' technique of dual x-ray absorptiometry (DXA). This study examined the correlation between quantitative ultrasound (QUS) measurements performed at the phalanges and conventional DXA measurements of the spine and hip in women with premature ovarian failure--a known risk factor for osteoporosis. Thirteen white Caucasian women suffering from premature ovarian failure and 19 age- and sex-matched controls were recruited into the study. DXA measurements were performed at the spine and hip, followed by quantitative ultrasonography at phalanges II-V of the non-dominant hand. Significant correlations were observed between the bone transit time (BTT) value from the Bone Profiler and bone mineral density measured at the spine (r=0.66). The spine Z-scores also correlated with many of the ultrasound values (r=0.44-0.63). Significant inverse correlations were observed between BMI, weight and ultrasound parameters (r=-0.48 to -0.78). We have reported moderate but significant correlations between phalangeal QUS and DXA parameters. The strongest correlation was observed between BTT and spine BMD, as well as between the Z-scores from the two devices. QUS parameters also demonstrated an inverse correlation with weight and BMI.