Assessment of perineal body properties in women with stress urinary incontinence using Transperineal shear wave elastography.

Limited data on the correlation between the perineal body (PB) and stress urinary incontinence (SUI) are available. The objectives of this study were to quantify the PB using shear wave elastography (SWE) technology with a high-frequency linear array probe to evaluate the relationship between the properties of PB and stress urinary incontinence (SUI). This study included 64 women with SUI and 70 female control participants. The length, height, perimeter, and area of PB in all participants were calculated using transperineal ultrasound, and the elasticity of PB was assessed by SWE at rest and during the maximal Valsalva maneuver, respectively. In addition, the comparison of PB parameters between the patients with SUI and the healthy participants was conducted. The transperineal ultrasound and SWE examination was performed in 134 participants, and the elastic modulus values were significantly increased from participants at rest to those during the maximal Valsalva maneuver in all participants (Emax: 35.59 versus 53.13 kPa, P < 0.001; and Emean: 26.97 versus 40.25 kPa, P < 0.001). Emax and Emean of PB exhibited significant differences during the maximal Valsalva maneuver between the SUI group and the control group (47.73 versus 58.06 kPa, P < 0.001; and 35.78 versus 44.33 kPa, P < 0.001) and had a negative correlation with SUI. The BMI and PB height during the maximal Valsalva maneuver in the SUI group were found to be significantly higher than that in healthy volunteers. Emax and Emean of PB negatively correlated with BMI during the maximal Valsalva maneuver (r = -0.277, P = 0.001 and r = -0.211, P = 0.014). ROC curve analysis demonstrated that PB perimeter of less than 12.68mm was strongly associated with SUI during the maximal Valsalva maneuver, and an Emax of less than 55.76 kPa had a 100% specificity in predicting SUI. SWE can quantify the elasticity of PB, identifying a significant difference between participants at rest and during Valsalva maneuver. In addition, the stiffness of the PB was significantly lower in women with SUI than in healthy women, which may provide a noninvasive clinical practice in SUI prediction.

Dual optical elastography detects TGF - ß -induced alterations in the biomechanical properties of skin scaffolds.

Significance: The skin's mechanical properties are tightly regulated. Various pathologies can affect skin stiffness, and understanding these changes is a focus in tissue engineering. Ex vivo skin scaffolds are a robust platform for evaluating the effects of various genetic and molecular interactions on the skin. Transforming growth factor-beta ( TGF - ß ) is a critical signaling molecule in the skin that can regulate the amount of collagen and elastin in the skin and, consequently, its mechanical properties. Aim: This study investigates the biomechanical properties of bio-engineered skin scaffolds, focusing on the influence of TGF - ß , a signaling molecule with diverse cellular functions. Approach: The TGF - ß receptor I inhibitor, galunisertib, was employed to assess the mechanical changes resulting from dysregulation of TGF - ß . Skin scaffold samples, grouped into three categories (control, TGF - ß -treated, and TGF - ß + galunisertib-treated), were prepared in two distinct culture media-one with aprotinin (AP) and another without. Two optical elastography techniques, namely wave-based optical coherence elastography (OCE) and Brillouin microscopy, were utilized to quantify the biomechanical properties of the tissues. Results: Results showed significantly higher wave speed (with AP, p < 0.001 ; without AP, p < 0.001 ) and Brillouin frequency shift (with AP, p < 0.001 ; without AP, p = 0.01 ) in TGF - ß -treated group compared with the control group. The difference in wave speed between the control and TGF - ß + galunisertib with ( p = 0.10 ) and without AP ( p = 0.36 ) was not significant. Moreover, the TGF - ß + galunisertib-treated group exhibited lower wave speed without and with AP and reduced Brillouin frequency shift than the TGF - ß -treated group without AP, further strengthening the potential role of TGF - ß in regulating the mechanical properties of the samples. Conclusions: These findings offer valuable insights into TGF - ß -induced biomechanical alterations in bio-engineered skin scaffolds, highlighting the potential of OCE and Brillouin microscopy in the development of targeted therapies in conditions involving abnormal tissue remodeling and fibrosis.

Real-time ultrasound elastography in the diagnosis of newly identified thyroid nodules in adults: the ElaTION RCT.

Background: Strain and shear wave elastography which is commonly used with concurrent real-time imaging known as real-time ultrasound shear/strain wave elastography is a new diagnostic technique that has been reported to be useful in the diagnosis of nodules in several organs. There is conflicting evidence regarding its benefit over ultrasound-guided fine-needle aspiration cytology alone in thyroid nodules. Objectives: To determine if ultrasound strain and shear wave elastography in conjunction with fine-needle aspiration cytology will reduce the number of patients who have a non-diagnostic first fine-needle aspiration cytology results as compared to conventional ultrasound-only guided fine-needle aspiration cytology. Design: A pragmatic, unblinded, multicentre randomised controlled trial. Setting: Eighteen centres with a radiology department across England. Participants: Adults who had not undergone previous fine-needle aspiration cytology with single or multiple nodules undergoing investigation. Interventions: Ultrasound shear/strain wave elastography-ultrasound guided fine-needle aspiration cytology (intervention arm) - strain or shear wave elastography-guided fine-needle aspiration cytology. Ultrasound-only guided fine-needle aspiration cytology (control arm) - routine ultrasound-only guided fine-needle aspiration cytology (the current standard recommended by the British Thyroid Association guidelines). Main outcome measure: The proportion of patients who have a non-diagnostic cytology (Thy 1) result following the first fine-needle aspiration cytology. Randomisation: Patients were randomised at a 1 : 1 ratio to the interventional or control arms. Results: A total of 982 participants (80% female) were randomised: 493 were randomised to ultrasound shear/strain wave elastography-ultrasound guided fine-needle aspiration cytology and 489 were randomised to ultrasound-only guided fine-needle aspiration cytology. There was no evidence of a difference between ultrasound shear/strain wave elastography and ultrasound in non-diagnostic cytology (Thy 1) rate following the first fine-needle aspiration cytology (19% vs. 16% respectively; risk difference: 0.030; 95% confidence interval -0.007 to 0.066; p = 0.11), the number of fine-needle aspiration cytologies needed (odds ratio: 1.10; 95% confidence interval 0.82 to 1.49; p = 0.53) or in the time to reach a definitive diagnosis (hazard ratio: 0.94; 95% confidence interval 0.81 to 1.10; p = 0.45). There was a small, non-significant reduction in the number of thyroid operations undertaken when ultrasound shear/strain wave elastography was used (37% vs. 40% respectively; risk difference: -0.02; 95% confidence interval -0.06 to 0.009; p = 0.15), but no difference in the number of operations yielding benign histology - 23% versus 24% respectively, p = 0.70 (i.e. no increase in identification of malignant cases) - or in the number of serious adverse events (2% vs. 1%). There was no difference in anxiety and depression, pain or quality of life between the two arms. Limitations: The study was not powered to detect differences in malignancy. Conclusions: Ultrasound shear/strain wave elastography does not appear to have additional benefit over ultrasound-guided fine-needle aspiration cytology in the diagnosis of thyroid nodules. Future work: The findings of the ElaTION trial suggest that further research into the use of shear wave elastography in the diagnostic setting of thyroid nodules is unlikely to be warranted unless there are improvements in the technology. The diagnostic difficulty in distinguishing between benign and malignant lesions still persists. Future studies might examine the role of genomic testing on fine-needle aspiration samples. There is growing use of targeted panels of molecular markers, particularly aimed at improving the diagnostic accuracy of indeterminate (i.e. Thy3) cytology results. The application of these tests is not uniform, and their cost effectiveness has not been assessed in large-scale trials. Study registration: This study is registered as ISRCTN (ISRCTN18261857). Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 12/19/04) and is published in full in Health Technology Assessment; Vol. 28, No. 46. See the NIHR Funding and Awards website for further award information.

About half the population will have lumps in their thyroid if examined by an ultrasound scan but may not know they have one. About one in twenty people will feel a thyroid lump in their neck at some time in their life, with about one in twenty of those being malignant. Currently, the recommended way of getting a diagnosis of thyroid nodules is by using ultrasound to guide a needle to get cells from the lump, called ultrasound-guided fine-needle aspiration cytology. These cells are examined to determine the cause of the lump. If there are enough cells, Doctors can then make a diagnosis of whether the lump is benign or malignant. If not, patients will undergo another ultrasound-guided fine-needle aspiration cytology. One in five ultrasound-guided fine-needle aspiration cytologies are non-diagnostic with an overall false-positive rate of approximately 24%. This means one in five patients, with benign disease, may undergo unnecessary diagnostic operations. Thyroid surgery carries risks of complications, which could be avoided if we had better ways to diagnose which patients actually need an operation. We conducted a randomised trial, ElaTION, to determine if a new technology called strain and shear wave elastography, commonly known as real-time elastography, would be better at helping the radiologist take a sufficient sample of cells and reduce the number of non-diagnostic results, reducing the number of fine-needle aspiration cytologies required to make a definitive diagnosis. Nine hundred eighty-two patients were recruited between 2015 and 2018 and followed up until the end of the trial. Patients were randomised into two groups: 489 patients received the standard ultrasound-guided fine-needle aspiration cytology alone, and 493 patients received ultrasound-guided fine-needle aspiration cytology + shear wave elastography. Ultrasound shear/strain wave elastography did not reduce non-diagnostic cytology at first fine-needle aspiration cytology or improve the likelihood of determining whether the lump is benign or malignant. The results of ElaTION do not support the use of shear wave elastography-fine-needle aspiration cytology in the diagnosis of thyroid nodules.

Diagnostic performance of new BAST score versus FIB-4 index in predicating of the liver fibrosis in patients with metabolic dysfunction-associated steatotic liver disease.

BACKGROUND AND AIM: Metabolic dysfunction-associated steatotic liver disease (MASLD) formerly known as non-alcoholic fatty liver disease (NAFLD) is the most common liver condition globally. The FIB-4 test is used to detect fibrosis in fatty liver disease but has limited accuracy in predicting liver stiffness, resulting in high rates of false positives and negatives. The new BAST scoring system, incorporating waist circumference, AST, and BMI, has been developed to assess the presence of fibrosis in NAFLD patients. This study compares the effectiveness of BAST and FIB-4 in predicting liver fibrosis in MASLD patients. PATIENTS AND METHODS: The study included 140 non-diabetic MASLD patients who underwent transient elastography measurement. BAST score and FIB-4 were calculated for each patient. Patients were grouped based on fibrosis severity; F1, F2, and F3-F4. The sensitivity and specificity of the BAST score and FIB-4 were assessed using receiver operating characteristic curves. RESULTS: The BAST score increased significantly with fibrosis progression from F1 to F3-F4. In differentiating advanced fibrosis (F2-F3) from mild/moderate fibrosis (F1-F2), the BAST score at cutoff ≤ - 0.451 showed better diagnostic performance with 90.70% sensitivity, 74.07% specificity, 84.8% PPV and 83.3% NPV compared to FIB-4 that had 60.47% sensitivity, 50.0% specificity, 65.8% PPV and 44.3% NPV. Similarly, for differentiating between F1 and F2 fibrosis, the BAST score at cutoff ≤ - 1.11 outperformed FIB-4, with 80.23% sensitivity, 79.49% specificity, 89.6% PPV and 64.6% NPV, while FIB-4 had 59.30% sensitivity, 51.28% specificity, 72.9% PPV and 36% NPV. CONCLUSIONS: The BAST score is a better predictor of liver fibrosis in MASLD compared to FIB-4, especially in cases of advanced fibrosis or cirrhosis.

A comparative study of histotripsy parameters for the treatment of fibrotic ex-vivo human benign prostatic hyperplasia tissue.

Histotripsy is a noninvasive focused ultrasound therapy that mechanically fractionates tissue to create well-defined lesions. In a previous clinical pilot trial to treat benign prostatic hyperplasia (BPH), histotripsy did not result in consistent objective improvements in symptoms, potentially because of the fibrotic and mechanically tough nature of this tissue. In this study, we aimed to identify the dosage required to homogenize BPH tissue by different histotripsy modalities, including boiling histotripsy (BH) and cavitation histotripsy (CH). A method for histotripsy lesion quantification via entropy (HLQE) analysis was developed and utilized to quantify lesion area of the respective treatments. These data were correlated to changes in mechanical stiffness measured by ultrasound shear-wave elastography before and after treatment with each parameter set and dose. Time points corresponding to histologically observed complete lesions were qualitatively evaluated and quantitatively measured. For the BH treatment, complete lesions occurred with > = 30 s treatment time, with a corresponding maximum reduction in stiffness of -90.9 ± 7.2(s.d.)%. High pulse repetition frequency (PRF) CH achieved a similar reduction to that of BH at 288 s (-91.6 ± 6.0(s.d.)%), and low-PRF CH achieved a (-82.1 ± 5.1(s.d.)%) reduction in stiffness at dose > = 144 s. Receiver operating characteristic curve analysis showed that a > ~ 75% reduction in stiffness positively correlated with complete lesions observed histologically, and can provide an alternative metric to track treatment progression.

Ultrasound shear wave elastography for assessing minor salivary gland involvement in anti-centromere antibody-positive primary Sjögren's syndrome: a retrospective study.

The aim of this study is to investigate salivary gland involvement in patients with anti-centromere antibody (ACA)-positive primary Sjögren's syndrome (pSS). We retrospectively evaluated 134 patients with pSS. Patients were divided into four groups based on the results of ACA and SSA antibodies. We compared clinical manifestations, laboratory findings, salivary gland shear wave elastography, minor salivary gland biopsy results, and EULAR Sjögren's syndrome disease activity index (ESSDAI) scores among the four groups. A total of 134 patients were classified as having pSS and divided into three groups based on serum ACA and anti-SSA antibody status: ACA + SSA + , ACA + SSA-, ACA-SSA + , and seronegative. The primary analysis focused on comparing the clinical and SWE findings between the ACA + SSA + and ACA + SSA- groups. In the double-positive group, SWE revealed fewer minor salivary glands along with higher mean (Emean) and maximum (Emax) values of Young's moduli than those in the ACA-negative group. Patients in the positive group had increased occurrence of Raynaud's phenomenon, liver involvement, and a higher incidence of malignancy (P < 0.05). ACA-positive pSS patients are a subgroup with different clinical manifestations and more pronounced involvement of the minor salivary glands. SWE findings revealed that ACA-positive patients exhibit significantly higher mean and maximum stiffness values compared to ACA-negative patients, indicating more extensive glandular fibrosis and involvement. These results underscore the utility of SWE as a valuable method for evaluating salivary gland pathology and supporting the stratification of pSS patients.

[Application and prospects of magnetic resonance imaging techniques in the diagnosis and evaluation of hepatocellular carcinoma].

Hepatocellular carcinoma (HCC) is the most common primary malignant tumor of the liver. MRI has become an important imaging method for non-invasive diagnosis and evaluation of HCC in clinics because of its advantageous aspects, such as its non-radiative nature, superior detection, and qualitative accuracy over CT and ultrasound. Various MRI techniques, including hepatobiliary-specific contrast agents, magnetic resonance elastography, diffusion-weighted imaging, and others, can diagnose HCC or evaluate its malignant biological behavior from different dimensions such as blood supply, cell function, tissue hardness, and water molecule diffusion. This article introduces the current status and prospects of various MRI techniques for HCC diagnosis and evaluation.

The value of shear wave elastography combined with red blood cell distribution width in evaluating arterial erectile dysfunction.

PURPOSE: A retrospective study was conducted to determine the value of shear wave elastography (SWE) and red blood cell distribution width (RDW) in the diagnosis of various forms of erectile dysfunction (ED). METHODS: With the method of Nocturnal Penile Tumescence and Rigidity (NPTR) and the screening method of Color Duplex Doppler Ultrasound (CDDU), hematological data were collected from 131 individuals, among whom 24 are with psychogenic ED, 48 are with non-arterial ED(NAED) and 59 are with arterial ED(AED) with erectile dysfunction. SWE value of penile corpus cavernosum(CCP) and cavernous arterial flow velocity were measured before (flaccid state) and after (erect state) intracavernous injection (ICI) in all patients. RESULTS: Among the AED patients and other types of ED patients, there were statistically significant differences in the abridged five-item International Index of Erectile Function (IIEF-5), red blood cell distribution width-coefficient of variation (RDW-CV), red blood cell distribution width-standard deviation (RDW-SD), and SWE values (all P < 0.01). In the AED patients, the IIEF-5 scores had a significant negative relationship with RDW-CV, RDW-SD, and SWE values, with SWE values having the strongest correlation. (p < 0.001, r=-0.638). CONCLUSION: The combination of RDW level and SWE value demonstrated the greatest performance in diagnosing AED, according to the receiver-operator characteristic(ROC) curve analysis (AUC = 0.870, p < 0.0001, cut-off value of 0.75, sensitivity of 74.6%, specificity of 91.7%).RDW and SWE value may develop into an incredibly simple, practical tool for predicting and diagnosing AED. TRIAL REGISTRATION: retrospectively registered.

Direct-Acting Antiviral Therapy in Patients with Chronic Hepatitis C Shows Liver Fibrosis Regression on Three Noninvasive Tests: A Puerto Rican Cohort.

OBJECTIVE: Direct-acting antiviral (DAA) drugs have resulted in high rates of virological cure in chronic hepatitis C (CHC)-infected patients. We used noninvasive tests to assess fibrosis in subjects who had been cured with DAA. METHODS: Retrospective data collection (2014-2019) from the medical record of CHC patients at the hepatology clinic was performed. Subjects co-infected with HIV and hepatitis B, post-liver transplant, and lost to follow-up were excluded. We evaluated fibrosis at baseline and 1 year after completing therapy using vibration-controlled transient elastography (VCTE), fibrosis-4 (FIB-4), and aspartate aminotransferase-toplatelet ratio index (APRI) scores. RESULTS: With 210 medical records reviewed, 41 were included. The mean age was 62.8 years; 61% were men. Significant fibrosis regression was observed 1-year post-treatment using 3 noninvasive methods: VCTE, APRI, and FIB-4 score. Prior to treatment, 46% of the patients had advanced fibrosis compared to 25% 1 year after treatment. The VCTE scores of 4 subjects (with body mass indices [BMIs] > 30) indicated a worsening of fibrosis. We did not find a statistically significant association between BMI and VCTE, FIB-4, or APRI score. CONCLUSION: In most CHC patients, DAA therapy leads to liver fibrosis regression. Obesity may play an important role in the worsening of hepatic fibrosis or the absence of fibrosis regression.

Early screening for chronic liver disease: impact of a FIB-4 first integrated care pathway to identify patients with significant fibrosis.

Liver fibrosis is often undetected whereas it is the determinant of liver-related mortality. We evaluate a pathway based on the systematic calculation of FIB-4 to screen for advanced hepatic fibrosis. Systematic calculation of FIB-4 was implemented in the centralized laboratory of a French University Hospital in 4 pilot departments. If ≥ 2.67, the FIB-4 result was returned to the prescribers, for patients between 18 and 70 years of age, with an incentive to measure liver stiffness by vibration controlled transient elastography. During a 2-years period, a FIB-4 was calculated in 2963 patients and 135 were ≥ 2.67 (4.6%). After exclusion of patients with a known cause of elevated FIB-4, 47 patients (34.8%) were eligible for elastography. Forty patients underwent elastography, but only 15% (7/47) at the spontaneous request of the referring physician. Fifteen patients were identified with significant fibrosis, among which 8 attended the scheduled specialist consultation, all with a confirmed diagnosis of cirrhosis. A sequential pathway based on the systematic calculation of FIB-4 enables the identification of patients with significant unknown liver fibrosis, allowing to refer them to specialized care. Raising awareness is essential to improve the care pathway.

Reproducibility and Repeatability of US Shear-Wave and Transient Elastography in Nonalcoholic Fatty Liver Disease.

Background US shear-wave elastography (SWE) and vibration-controlled transient elastography (VCTE) enable assessment of liver stiffness, an indicator of fibrosis severity. However, limited reproducibility data restrict their use in clinical trials. Purpose To estimate SWE and VCTE measurement variability in nonalcoholic fatty liver disease (NAFLD) within and across systems to support clinical trial diagnostic enrichment and clinical interpretation of longitudinal liver stiffness. Materials and Methods This prospective, observational, cross-sectional study (March 2021 to November 2021) enrolled adults with NAFLD, stratified according to the Fibrosis-4 (FIB-4) index (≤1.3, >1.3 and <2.67, ≥2.67), at two sites to assess SWE with five US systems and VCTE with one system. Each participant underwent 12 elastography examinations over two separate days within 1 week, with each day's examinations conducted by a different operator. VCTE and SWE measurements were reported in units of meters per second. The primary end point was the different-day, different-operator reproducibility coefficient (RDCDDDO) pooled across systems for SWE and individually for VCTE. Secondary end points included system-specific RDCDDDO, same-day, same-operator repeatability coefficient (RCSDSO), and between-system same-day, same-operator reproducibility coefficient. The planned sample provided 80% power to detect a pooled RDCDDDO of less than 35%, the prespecified performance threshold. Results A total of 40 participants (mean age, 60 years ± 10 [SD]; 24 women) with low (n = 17), intermediate (n = 15), and high (n = 8) FIB-4 scores were enrolled. RDCDDDO was 30.7% (95% upper bound, 34.4%) for SWE and 35.6% (95% upper bound, 43.9%) for VCTE. SWE system-specific RDCDDDO varied from 24.2% to 34.3%. The RCSDSO was 21.0% for SWE (range, 13.9%-35.0%) and 19.6% for VCTE. The SWE between-system same-day, same-operator reproducibility coefficient was 52.7%. Conclusion SWE met the prespecified threshold, RDCDDDO less than 35%, with VCTE having a higher RDCDDDO. SWE variability was higher between different systems. These estimates advance liver US-based noninvasive test qualification by (a) defining expected variability, (b) establishing that serial examination variability is lower when performed with the same system, and (c) informing clinical trial design. ClinicalTrials.gov Identifier NCT04828551 © RSNA, 2024 Supplemental material is available for this article.

Revealing regional variations in scleral shear modulus in a rabbit eye model using multi-directional ultrasound optical coherence elastography.

The mechanical properties of the sclera play a critical role in supporting the ocular structure and maintaining its shape. However, non-invasive measurements to quantify scleral biomechanics remain challenging. Recently introduced multi-directional optical coherence elastography (OCE) combined with an air-coupled ultrasound transducer for excitation of elastic surface waves was used to estimate phase speed and shear modulus in ex vivo rabbit globes (n = 7). The scleral phase speed (12.1 ± 3.2 m/s) was directional-dependent and higher than for corneal tissue (5.9 ± 1.4 m/s). In the tested locations, the sclera proved to be more anisotropic than the cornea by a factor of 11 in the maximum of modified planar anisotropy coefficient. The scleral shear moduli, estimated using a modified Rayleigh-Lamb wave model, showed significantly higher values in the circumferential direction (65.4 ± 31.9 kPa) than in meridional (22.5 ± 7.2 kPa); and in the anterior zone (27.3 ± 9.3 kPa) than in the posterior zone (17.8 ± 7.4 kPa). The multi-directional scanning approach allowed both quantification and radial mapping of estimated parameters within a single measurement. The results indicate that multi-directional OCE provides a valuable non-invasive assessment of scleral tissue properties that may be useful in the development of improved ocular models, the evaluation of potential myopia treatment strategies, and disease characterization and monitoring.

Characterizing dispersion in bovine liver using ARFI-based shear wave rheometry.

Background:Dispersion presents both a challenge and a diagnostic opportunity in shear wave elastography (SWE).Shear Wave Rheometry(SWR) is an inversion technique for processing SWE data acquired using an acoustic radiation force impulse (ARFI) excitation. The main advantage of SWR is that it can characterize the shear properties of homogeneous soft media over a wide frequency range. Assumptions associated with SWR include tissue homogeneity, tissue isotropy, and axisymmetry of the ARFI excitation).Objective:Evaluate the validity of the SWR assumptions in ex vivo bovine liver.Approach:SWR was used to measure the shear properties of bovine liver tissue as function of frequency over a large frequency range. Assumptions associated with SWR (tissue homogeneity, tissue isotropy, and axisymmetry of the ARFI excitation) were evaluated through measurements performed at multiple locations and probe orientations. Measurements focused on quantities that would reveal violations of the assumptions.Main results:Measurements of shear properties were obtained over the 25-250 Hz range, and showed a 4-fold increase in shear storage modulus (from 1 to 4 kPa) and over a 10-fold increase in the loss modulus (from 0.2 to 3 kPa) over that decade-wide frequency range. Measurements under different conditions were highly repeatable, and model error was low in all cases.Significance and Conclusion:SWR depends on modeling the ARFI-induced shear wave as a full vector viscoelastic shear wave resulting from an axisymmetric source; it is agnostic to any specific rheological model. Despite this generality, the model makes three main simplifying assumptions. These results show that the modeling assumptions used in SWR are valid in bovine liver over a wide frequency band.

Tumor spheroid elasticity estimation using mechano-microscopy combined with a conditional generative adversarial network.

BACKGROUND AND OBJECTIVES: Techniques for imaging the mechanical properties of cells are needed to study how cell mechanics influence cell function and disease progression. Mechano-microscopy (a high-resolution variant of compression optical coherence elastography) generates elasticity images of a sample undergoing compression from the phase difference between optical coherence microscopy (OCM) B-scans. However, the existing mechano-microscopy signal processing chain (referred to as the algebraic method) assumes the sample stress is uniaxial and axially uniform, such that violation of these assumptions reduces the accuracy and precision of elasticity images. Furthermore, it does not account for prior information regarding the sample geometry or mechanical property distribution. In this study, we investigate the feasibility of training a conditional generative adversarial network (cGAN) to generate elasticity images from phase difference images of samples containing a cell spheroid embedded in a hydrogel. METHODS: To construct the cGAN training and simulated test sets, we generated 30,000 artificial elasticity images using a parametric model and computed the corresponding phase difference images using finite element analysis to simulate compression applied to the artificial samples. We also imaged real MCF7 breast tumor spheroids embedded in hydrogel using mechano-microscopy to construct the experimental test set and evaluated the cGAN using the algebraic elasticity images and co-registered OCM and confocal fluorescence microscopy (CFM) images. RESULTS: Comparison with the simulated test set ground truth elasticity images shows the cGAN produces a lower root mean square error (median: 3.47 kPa, 95 % confidence interval (CI) [3.41, 3.52]) than the algebraic method (median: 4.91 kPa, 95 % CI [4.85, 4.97]). For the experimental test set, the cGAN elasticity images contain features resembling stiff nuclei at locations corresponding to nuclei seen in the algebraic elasticity, OCM, and CFM images. Furthermore, the cGAN elasticity images are higher resolution and more robust to noise than the algebraic elasticity images. CONCLUSIONS: The cGAN elasticity images exhibit better accuracy, spatial resolution, sensitivity, and robustness to noise than the algebraic elasticity images for both simulated and real experimental data.

The Application Value of Using Semiquantitative and Quantitative Parameters in Multimodal Ultrasound to Distinguish Between Benign and Malignant BI-RADS 4 Lesions.

ABSTRACT: This study aims to explore the value of real-time strain elastography (RTE) and contrast-enhanced ultrasonography (CEUS) in the diagnosis of breast BI-RADS 4 lesions. It collected 85 cases (totaling 85 lesions) diagnosed with breast BI-RADS 4 through routine ultrasound from October 2020 to December 2022 in Huangshan City People's Hospital. All lesions underwent RTE and CEUS examination before surgery, and the ImageJ software was used to measure the periphery of lesion images in the enhancement peak mode and grayscale mode to calculate the contrast-enhanced ultrasound area ratio. The diagnostic capabilities of single-modal and multimodal ultrasound examination for the malignancy of breast BI-RADS 4 lesions were compared using the receiver operating characteristic curve; the Spearman correlation analysis was adopted to evaluate the correlation between multimodal ultrasound and CEUS area ratio. As a result, among the 85 lesions, 51 were benign, and 34 were malignant. The areas under the curve (AUCs) of routine ultrasound (US), US + RTE, US + CEUS, and US + RTE + CEUS were 0.816, 0.928, 0.953, and 0.967, respectively, with the combined method showing a higher AUC than the single application. The AUC of the CEUS area ratio diagnosing breast lesions was 0.888. There was a strong positive correlation (r = 0.819, P < 0.001) between the diagnostic performance of US + RTE + CEUS and the CEUS area ratio. In conclusion, based on routine ultrasound, the combination of RTE and CEUS can further improve the differential diagnosis of benign and malignant lesions in breast BI-RADS 4.

Weight-specific normal liver stiffness values in children.

BACKGROUND: Two-dimensional (2-D) shear wave elastography is a commonly used sonographic elastography method for the noninvasive measurement of liver stiffness. There is little liver stiffness data available in the pediatric population and its association with the child's weight is scarce. OBJECTIVE: The principal aim of our study was to determine weight-specific reference liver stiffness values in a pediatric population free of liver disease. MATERIALS AND METHODS: In this retrospective single-center study, 2-D shear wave elastography values were recorded in children with no history of liver disease and with a clinically indicated ultrasound examination, between April 2021 and July 2022. Examinations were performed using an Aplio i800 and two Aplio a450 (Canon Medical Systems), with a convex probe (i8CX1 or 8C1 transducers). This population was divided into ten weight groups. We evaluated the relation between weight and liver elasticity values and compared right and left lobe measurements. RESULTS: During the period of the study, 235 children were included. We then excluded 64 patients (weight not available = 13, interquartile range to median ratio (IQR/M) greater than 30% = 51). On the final sample (171 patients, median age 6.5 years [0-18], median weight 22.6 kg [2.5-80]), stiffness values showed a global significant trend to increase with weight. In each group, there was no significant difference between right and left liver stiffness values. The mean normal liver stiffness value including all children was 5.3 ± 1.1 kPa. CONCLUSION: Liver stiffness in our pediatric sample with no history of liver disease increases with weight. These data may help to distinguish normal from pathological elastography values.

The value of real-time shear wave elastography in spontaneous preterm birth.

This study aimed to investigate the predictive value of real-time shear wave elastography (SWE) for spontaneous preterm birth (SPB). This study prospectively selected 175 women with singleton pregnancies at 16 to 36 weeks of gestation. Cervical length (CL) and uterocervical angle (UCA) were measured using transvaginal ultrasonography. Real-time shear wave elastography was used to measure Young's modulus values, including the average Young's modulus (Emean) and the maximum Young's modulus (Emax) at 4 points: point A on the inner lip of the cervical os, point B on the outer lip of the cervical os, point C on the inner lip of the external os, and point D on the outer lip of the external os. Receiver operating characteristic (ROC) curve analysis was performed to compare the accuracy of Young's modulus values at the 4 points, CL, and UCA in predicting SPB. Significant variables were used to construct a binary logistic regression model to predict the multifactorial predictive value of SPB, which was evaluated using an ROC curve. A total 176 valid cases, including 160 full-term pregnancies and 16 SPB, were included in this study. Receiver operating characteristic curve analysis revealed that Emean at point A, as well as Emean and Emax at point D, had a relatively high accuracy in diagnosing SPB, with area under the curve values of 0.704, 0.708, and 0.706, respectively followed by CL (0.670), SWE at point C (Emean 0.615, Emax 0.565), SWE at point B (Emean 0.577, Emax 0.584), and UCA (0.476). Binary logistic regression analysis showed that comorbidities during pregnancy (including diabetes mellitus, hypertension, cholestasis and thyroid dysfunction), CL, and Emean at point A were independent predictors of preterm birth. In addition, the AUC value of the logistic regression model's ROC curve was 0.892 (95% CI: 0.804-0.981), with a sensitivity of 0.867, specificity of 0.792, and Youden's index of 0.659, indicating that the regression model has good predictive ability for SPB. Real-time shear wave elastography showed a higher predictive value for SPB than CL and UCA. The SWE combined with CL and comorbidities during pregnancy model has a good predictive ability for SPB.

Prevalence, clinical significance and prognosis value of liver stiffness measurement anomalies in transthyretin cardiac amyloidosis.

Background - Laboratory liver anomalies are common in cardiac amyloidosis; however, their significance regarding liver stiffness is unknown. The aim of this study was to investigate the prevalence, clinical significance, and prognostic value of liver stiffness measurement (LSM) anomalies in transthyretin cardiac amyloidosis (ATTR-CA). Methods - Consecutive patients diagnosed with ATTR-CA who underwent liver stiffness assessment were included in the study. Demographic, clinical, laboratory, transthoracic echocardiography and liver stiffness data were retrospectively collected. LSM was obtained through either transient elastography or supersonic shear imaging. Patient cohort was divided in two groups according to a 10 kPa threshold. Follow up data were collected for the occurrence of hospitalization for heart failure and all-cause death. Results - Two hundred and eighty-four patients with ATTR-CA - 26 (9 %) hereditary variant ATTR, 258 (91 %) wild-type ATTR - were included. A LSM over 10 kPa was found in 4 (15 %) and 98 (38 %) patients with ATTRv and ATTRwt respectively (p = 0.02). Among patients with ATTRwt, high LSM was more frequent in advanced stages of ATTR-CA and was associated with increased risk of hospitalization for heart failure after multivariate analysis with a hazard ratio of 2.41 [1.05-5.55] (p = 0.04). Among patients with NYHA stage 1, 28 % presented high LSM associated with high NT-proBNP levels. Integration of high LSM with NT-proBNP and estimated glomerular filtration rate provided a better estimate of patient survival. Conclusion - LSM over 10 kPa is found in up to 36 % of patients with ATTR-CA and is associated with advanced stages of cardiomyopathy and increased risk of hospitalization for heart failure in ATTRwt patients.

Nomogram based on liver stiffness and spleen area with ultrasound for posthepatectomy liver failure: A multicenter study.

BACKGROUND: Liver stiffness (LS) measurement with two-dimensional shear wave elastography (2D-SWE) correlates with the degree of liver fibrosis and thus indirectly reflects liver function reserve. The size of the spleen increases due to tissue proliferation, fibrosis, and portal vein congestion, which can indirectly reflect the situation of liver fibrosis/cirrhosis. It was reported that the size of the spleen was related to posthepatectomy liver failure (PHLF). So far, there has been no study combining 2D-SWE measurements of LS with spleen size to predict PHLF. This prospective study aimed to investigate the utility of 2D-SWE assessing LS and spleen area (SPA) for the prediction of PHLF in hepatocellular carcinoma (HCC) patients and to develop a risk prediction model. AIM: To investigate the utility of 2D-SWE assessing LS and SPA for the prediction of PHLF in HCC patients and to develop a risk prediction model. METHODS: This was a multicenter observational study prospectively analyzing patients who underwent hepatectomy from October 2020 to March 2022. Within 1 wk before partial hepatectomy, ultrasound examination was performed to measure LS and SPA, and blood was drawn to evaluate the patient's liver function and other conditions. Least absolute shrinkage and selection operator logistic regression and multivariate logistic regression analysis was applied to identify independent predictors of PHLF and develop a nomogram. Nomogram performance was validated further. The diagnostic performance of the nomogram was evaluated with receiver operating characteristic curve compared with the conventional models, including the model for end-stage liver disease (MELD) score and the albumin-bilirubin (ALBI) score. RESULTS: A total of 562 HCC patients undergoing hepatectomy (500 in the training cohort and 62 in the validation cohort) were enrolled in this study. The independent predictors of PHLF were LS, SPA, range of resection, blood loss, international normalized ratio, and total bilirubin. Better diagnostic performance of the nomogram was obtained in the training [area under receiver operating characteristic curve (AUC): 0.833; 95% confidence interval (95%CI): 0.792-0.873; sensitivity: 83.1%; specificity: 73.5%] and validation (AUC: 0.802; 95%CI: 0.684-0.920; sensitivity: 95.5%; specificity: 52.5%) cohorts compared with the MELD score and the ALBI score. CONCLUSION: This PHLF nomogram, mainly based on LS by 2D-SWE and SPA, was useful in predicting PHLF in HCC patients and presented better than MELD score and ALBI score.