PurposeThis study compared the imaging performance of low–mechanical-index phase-inversion harmonic imaging (low-MI PIHI) with conventional contrast-enhanced ultrasonography (CEUS) during the Kupffer phase (KP) of Sonazoid-enhanced imaging for visualizing hepatic lesions, focusing on lesion conspicuity and overall image quality.MethodsThis prospective study was approved by the Institutional Review Board and included 71 patients with 72 focal liver lesions examined between February 2023 and January 2024. All patients underwent Sonazoid-enhanced CEUS. Three image sets were acquired for each lesion: baseline B-mode imaging, conventional KP imaging, and low-MI PIHI KP imaging. Two independent radiologists, blinded to clinical information, independently evaluated lesion conspicuity, border delineation, and overall image quality using a 5-point Likert scale.ResultsBaseline B-mode imaging demonstrated the lowest lesion conspicuity scores, which improved with conventional KP imaging and were highest with low-MI PIHI KP imaging (all P<0.001). Compared with conventional KP imaging, low-MI PIHI KP imaging provided significantly higher lesion conspicuity for both reviewers (P<0.001), with the most pronounced improvement observed in hepatocellular carcinomas within cirrhotic livers, where conspicuity scores nearly doubled (P<0.001). Lesion border delineation also improved significantly for both reviewers (P<0.001). Overall image quality was consistently superior with low-MI PIHI KP imaging (P≤0.003). These advantages were particularly evident for small lesions (≤2 cm) and in cirrhotic liver backgrounds.ConclusionLow-MI PIHI KP imaging significantly enhances hepatic lesion conspicuity and margin delineation compared with conventional CEUS harmonic imaging, while also improving overall image quality. These improvements may support more confident lesion detection and facilitate image-guided procedures.

PurposeThis study aimed to evaluate the effect of breath control on the reliability of two-dimensional shear wave elastography (2D-SWE) and shear wave dispersion (SWD) measurements in pediatric patients.MethodsThis study included a retrospective cohort of 163 children and a prospective cohort of 27 children (aged 8-17 years). All participants underwent 2D-SWE and SWD under both free-breathing and breath-hold conditions between September 2021 and February 2023. The prospective cohort also underwent magnetic resonance elastography (MRE). Liver stiffness and dispersion values were compared between respiratory conditions. Inter- and intra-rater agreements were assessed, and correlations with MRE were analyzed in the prospective cohort.ResultsLiver stiffness and dispersion values were significantly higher during free-breathing compared to breath-hold (mean differences: 0.22 kPa and 0.39 m/s/kHz, respectively; both P<0.01). Breath-hold improved inter-rater agreement for 2D-SWE (intraclass correlation coefficient [ICC], 0.94 vs. 0.83; P=0.005) and SWD (ICC, 0.85 vs. 0.70; P=0.048). Intra-rater agreement for 2D-SWE (ICC, 0.88 vs. 0.88; P>0.99) and SWD (ICC, 0.70 vs. 0.74; P=0.396) remained moderate to good and did not differ significantly between conditions. The correlation between 2D-SWE and MRE was stronger under breath-hold than free-breathing (r=0.73 vs. r=0.56), although this difference was not statistically significant (P=0.299).ConclusionBreath-holding increases the reliability of pediatric 2D-SWE and SWD by improving inter-rater agreement and correlation with MRE. However, free-breathing also demonstrates comparable reproducibility with minimal bias, supporting its clinical feasibility for use in uncooperative pediatric patients.

PurposeThis study aimed to investigate the effects of therapeutic ultrasound (TUS) combined with microbubbles and gemcitabine on cell viability, apoptosis, and autophagy in pancreatic cancer cells. The goal was to elucidate the cell death mechanisms by which TUS enhances drug delivery and therapeutic efficacy.MethodsHuman pancreatic ductal adenocarcinoma CFPAC-1 cells were treated with varying TUS intensities (0.29 MPa/continuous wave, 0.42 MPa/50% duty cycle, and 0.86 MPa/10% duty cycle), microbubble volumes (0, 10, and 50 μL), and gemcitabine concentrations (0 μg/mL and 2 μg/mL). Cell viability was assessed by MTT assay, apoptosis by annexin V/propidium iodide staining and flow cytometry, and autophagy by an autophagy detection kit. Statistical analyses included three-way analysis of variance and post hoc Tukey honestly significant difference tests to evaluate the effects and interactions of treatment variables.ResultsTUS combined with microbubbles and gemcitabine significantly reduced cell viability, induced apoptosis, and modulated autophagy in pancreatic cancer cells. Higher ultrasound intensities (with lower duty cycles) and increased microbubble volumes further enhanced these effects. Autophagy activation varied across treatment conditions. Under certain parameters, autophagy exhibited dose-dependent suppression with higher-intensity TUS, thereby promoting apoptosis-mediated cell death.ConclusionTUS combined with microbubbles and gemcitabine synergistically induces cell death in pancreatic cancer cells through mechanical bioeffects and enhanced drug delivery, mediated by both apoptosis induction and autophagy modulation. These findings highlight a promising strategy for improving pancreatic cancer treatment outcomes, warranting further in vivo and clinical studies to optimize parameters and assess translational potential.

PurposeThe study investigated whether incorporating magnetic resonance imaging (MRI) alongside ultrasonography (US) in the preoperative evaluation is associated with differing survival outcomes between male and female breast cancer patients in a matched analysis. Additionally, clinicopathological prognostic factors were analyzed.MethodsBetween January 2005 and December 2020, 93 male and 28,191 female patients who underwent breast surgery were screened. Exact matching analysis was conducted for age, pathologic T and N stages, and molecular subtypes. The clinicopathological characteristics and preoperative imaging methods of the matched cohorts were reviewed. Disease-free survival (DFS) and overall survival (OS) were assessed using Kaplan-Meier analysis, and Cox proportional hazards regression analysis was used to identify prognostic factors.ResultsA total of 328 breast cancer patients (61 men and 267 women) were included in the matched analysis. Male patients had worse DFS (10-year DFS, 70.6% vs. 89.2%; P=0.001) and OS (10-year OS, 64.4% vs. 96.3%; P<0.001) than female patients. The pathologic index cancer size (hazard ratio [HR], 2.013; 95% confidence interval [CI], 1.063 to 3.810; P=0.032) was associated with worse DFS, whereas there were no significant factors associated with OS. Adding MRI to US for preoperative evaluation was not associated with DFS (HR, 1.117; 95% CI, 0.223 to 5.583; P=0.893) or OS (HR, 1.529; 95% CI, 0.300 to 7.781; P=0.609) in male patients.ConclusionAdding breast MRI to US in the preoperative evaluation was not associated with survival outcomes in male breast cancer patients, and the pathologic index cancer size was associated with worse DFS.

PurposeThis study aimed to determine whether micro-flow imaging (MFI) offers diagnostic performance comparable to that of contrast-enhanced ultrasonography (CEUS) in detecting segmental congestion among patients undergoing living donor liver transplantation (LDLT).MethodsData from 63 patients who underwent LDLT between May and December 2022 were retrospectively analyzed. MFI and CEUS data collected on the first postoperative day were quantified. Segmental congestion was assessed based on imaging findings and laboratory data, including liver enzymes and total bilirubin levels. The reference standard was a postoperative contrast-enhanced computed tomography scan performed within 2 weeks of surgery. Additionally, a subgroup analysis examined patients who underwent reconstruction of the middle hepatic vein territory.ResultsThe sensitivity and specificity of MFI were 73.9% and 67.5%, respectively. In comparison, CEUS demonstrated a sensitivity of 78.3% and a specificity of 75.0%. These findings suggest comparable diagnostic performance, with no significant differences in sensitivity (P=0.655) or specificity (P=0.257) between the two modalities. Additionally, early postoperative laboratory values did not show significant differences between patients with and without congestion. The subgroup analysis also indicated similar diagnostic performance between MFI and CEUS.ConclusionMFI without contrast enhancement yielded results comparable to those of CEUS in detecting segmental congestion after LDLT. Therefore, MFI may be considered a viable alternative to CEUS.

PurposeDeep learning–based image enhancement has significant potential in the field of ultrasound image processing, as it can accurately model complicated nonlinear artifacts and noise, such as ultrasonic speckle patterns. However, training deep learning networks to acquire reference images that are clean and free of noise presents significant challenges. This study introduces an unsupervised deep learning framework, termed speckle-to-speckle (S2S), designed for speckle and noise suppression. This framework can complete its training without the need for clean (speckle-free) reference images.MethodsThe proposed network leverages statistical reasoning for the mutual training of two in vivo images, each with distinct speckle patterns and noise. It then infers speckle- and noise-free images without needing clean reference images. This approach significantly reduces the time, cost, and effort experts need to invest in annotating reference images manually.ResultsThe experimental results demonstrated that the proposed approach outperformed existing techniques in terms of the signal-to-noise ratio, contrast-to-noise ratio, structural similarity index, edge preservation index, and processing time (up to 86 times faster). It also performed excellently on images obtained from ultrasound scanners other than the ones used in this work.ConclusionS2S demonstrates the potential of employing an unsupervised learning-based technique in medical imaging applications, where acquiring a ground truth reference is challenging.

PurposeThis study evaluated the elastic characteristics of the pulmonary trunk and distal branches in fetuses diagnosed with tetralogy of Fallot (TOF) using Doppler echocardiography.MethodsData on 42 fetuses diagnosed with TOF and 84 gestational age–matched normal fetuses were prospectively collected from the Second Xiangya Hospital of Central South University between August 2022 and January 2023. The severity of TOF was classified into three categories based on the z-score of the pulmonary annulus diameter: mild (z-score ≥-2), moderate (-4<z-score<-2), and severe (z-score ≤-4). Pulmonary artery stiffness (PAS) in the main pulmonary artery (MPA), distal left pulmonary artery (DLPA), and distal right pulmonary artery (DRPA) was measured using pulsed-wave Doppler imaging. Differences in clinical data and echocardiographic parameters were compared between the TOF group and the normal group, as well as among TOF subgroups.ResultsCompared with the normal group, the MPA-PAS in fetuses with TOF was significantly higher, while the DLPA-PAS and DRPA-PAS were notably lower (all P<0.05). The MPA-PAS of fetuses with severe TOF was higher than that of those with mild and moderate TOF (all P<0.05). However, there were no significant differences in the DLPA-PAS or DRPA-PAS among fetuses with mild, moderate, and severe TOF (all P>0.05).ConclusionFetuses diagnosed with TOF exhibited increased vascular stiffness in the MPA and reduced stiffness in the distal pulmonary artery (PA). Larger-scale follow-up studies are required to elucidate the relationships between these changes in vascular stiffness and PA development in patients with TOF.

The goal of this study was to examine changes in testicular stiffness at various intervals after the induction of testicular torsion, as well as to assess the predictive value of testicular stiffness for testicular spermatogenesis after torsion. Sixty healthy male rabbits were randomly assigned to one of three groups: complete testicular torsion, incomplete testicular torsion, or control. All rabbits underwent preoperative and postoperative scrotal ultrasonography, including shear wave elastography (SWE), at predetermined intervals. Changes in SWE values were analyzed and compared using repeatedmeasures analysis of variance. To assess the diagnostic performance of SWE in determining the degree of spermatogenic function impairment, the areas under the receiver operating characteristic curves (AUCs) were calculated. SWE measurements in both central and peripheral zones of the testicular parenchyma affected by torsion demonstrated significant negative correlations with spermatogenesis, with coefficients of r=-0.759 (P<0.001) and r=-0.696 (P<0.001), respectively. The AUCs of SWE measurements in the central or peripheral zones of the torsed testicular parenchyma were 0.886 (sensitivity, 83.3%; specificity, 100%) and 0.824 (sensitivity, 83.3%; specificity, 73.3%) for distinguishing between hypospermatogenesis and spermatogenic arrest, respectively (P=0.451, DeLong test). Variations in the stiffness of both central and peripheral regions of the testicular parenchyma correlate with the extent and duration of torsion, exhibiting a specific pattern. The "stiff ring sign" is the characteristic SWE finding associated with testicular torsion. SWE appears to aid in the non-invasive determination of the extent of spermatogenic damage in torsed testes.

This study evaluated the value of contrast-enhanced ultrasonography (CEUS) in the ultrasound-guided microwave ablation (MWA) treatment of symptomatic focal uterine adenomyosis. This retrospective study was conducted between March 2020 and January 2023, enrolling 52 patients with symptomatic focal uterine adenomyosis who had undergone MWA. All patients were examined with CEUS before and after MWA. The non-perfused volume (NPV) was compared between CEUS and dynamic contrast-enhanced magnetic resonance imaging (DCEMRI) following ablation. Therapeutic efficacy and safety were evaluated at 3-, 6-, and 12-month follow-ups. Additionally, this study explored the correlations between pre-treatment CEUS features and a volume reduction ratio indicating sufficient ablation, defined as 50% or more at the 3-month follow-up. No significant differences in NPV were noted between CEUS and DCE-MRI immediately after MWA and during follow-up (all P>0.05). At the 3-month follow-up, the median VRRs for the uterus and adenomyosis were 33.2% and 63.9%, respectively. Sufficient ablation was achieved in 69.2% (36/52) of adenomyosis cases, while partial ablation was observed in the remaining 30.8% (16/52). The identification of non-enhancing areas on pre-treatment CEUS was associated with sufficient ablation (P=0.016). At the 12-month follow-up, significant decreases were observed in both the uterine and adenomyosis volumes (all P<0.001). Dysmenorrhea and menorrhagia were significantly alleviated at 12 months, and no major complications were encountered. CEUS can be used to evaluate the ablation zone of focal adenomyosis that has been treated with MWA, similarly to DCE-MRI. The identification of non-enhancing areas on pretreatment CEUS indicates satisfactory treatment outcomes.