Ultrasonography最新文献

Purpose: This study evaluated the 3-year safety and efficacy of microwave ablation (MWA) as an alternative to radiofrequency ablation in Korean patients with hepatocellular carcinoma (HCC).

Methods: In this prospective single-center study, 33 adults with a single HCC lesion (2-5 cm; Barcelona Clinic Liver Cancer stage A) were enrolled between December 2017 and May 2020. All underwent ultrasound-guided MWA using the NEUWAVE system. One patient did not complete post-treatment evaluation and two had protocol deviations, yielding a full analysis set of 30 patients and a safety analysis set of 33 patients. Study endpoints included technical success (TS), technique efficacy (TE), local tumor progression (LTP), overall survival (OS), and adverse events (AEs) over a 3-year follow-up period.

Results: All 33 patients were included in the safety analysis, while 30 were included in the efficacy analysis. Most patients were male (83.3%), with a median age of 64 years and a mean tumor size of 2.5±0.6 cm. Median follow-up was 36.2 months. TS and TE were achieved in all cases. The 3-year cumulative LTP rate was 7.3%, and the 3-year OS rate was 90.0%. Minor AEs occurred in 54.5% of patients, most commonly post-ablation pain and fever. Two patients (6.1%) experienced major AEs, including pyrexia and duodenal thermal injury. No procedure- or device-related deaths occurred.

Conclusion: MWA appears to be a safe and effective treatment for early-stage HCC, demonstrating durable tumor control and a low incidence of major complications over 3 years.

Purpose: This study aimed to analyze the ultrasonographic characteristics of differentiated thyroid cancer (DTC) with multigenic co-mutations and to establish a predictive model using contrast-enhanced ultrasonography (CEUS).

Methods: This retrospective study included consecutive patients with pathologically confirmed DTC who underwent preoperative CEUS and next-generation sequencing at the authors' institution between September 2021 and December 2023. Clinical and CEUS features were compared between patients with and without multigenic co-mutations. Bayesian logistic regression (non-informative normal priors) was applied for predictor selection and model development, with Markov-chain Monte Carlo (MCMC) convergence checks and posterior predictive validation. Internal validation was performed using bootstrap resampling (n=1,000 iterations) to evaluate model stability.

Results: A total of 116 patients (mean age, 39.84±11.02 years; 33 men) were included, of whom 12 had multigenic co-mutations and 104 did not. Patients with multigenic co-mutations demonstrated a higher incidence of aggressive histological subtypes (25.0% vs. 1.9%, P=0.008) and lymph node metastasis (83.3% vs. 51.9%, P=0.038). Tumor size, enhancement homogeneity, and contrast agent arrival time were identified as significant predictors, with robust posterior distributions (all inclusion probabilities >0.9) and satisfactory MCMC convergence (potential scale reduction factor <1.01). The model achieved an area under the curve (AUC) of 0.873, with posterior predictive checks confirming favorable predicted-observed agreement (coverage ≥0.85). Internal validation with 1,000 bootstrap replicates yielded a consistent AUC of 0.880 (95% confidence interval, 0.745 to 0.978).

Conclusion: The CEUS-based predictive model demonstrated strong discrimination for detecting multigenic co-mutations in differentiated thyroid cancer; however, external validation is required to confirm its clinical applicability.

Purpose: This study investigated differences in endothelial cell dysfunction (ECD) and vascular response between hypertensive (HT) and non-hypertensive (NHT) individuals, as evaluated by high-resolution flow-mediated dilation (hrFMD) using a 24-MHz ultrasound probe.

Methods: The study included 31 participants in the HT group and 29 in the NHT group. Clinical data, laboratory findings, and carotid intima-media thickness (cIMT) were measured, as were brachial artery systolic and diastolic diameters at baseline and 30, 60, and 120 seconds after a 5-minute cuff occlusion. Based on these measurements, systolic (TERS) and diastolic (TERD) traditional expansion ratios (TER), as well as a new expansion ratio (NER), were calculated for each post-occlusion time point. Differences, correlations, and multivariable logistic regression analyses were used to evaluate associations between ECD and hrFMD indices, with odds ratios (ORs) and 95% confidence intervals (CIs) reported.

Results: At 60 seconds, NER and TER values in the HT group were significantly lower than in the NHT group. Most participants in the NHT (22/29, 75.8%) and HT (21/31, 67.7%) groups exhibited peak vasodilation at NER60. NER60 was negatively correlated with age (r=-0.603, P<0.001), cIMT (r=-0.328, P=0.011), and systolic blood pressure (r=-0.277, P=0.032). NER60 was associated with hypertension-related ECD independently of major cardiovascular risk factors (OR, 0.025; 95% CI, 0.002 to 0.316; P=0.004).

Conclusion: In hrFMD, NER60 was significantly lower in HT than in NHT participants and may represent a surrogate marker for impaired vascular reactivity associated with hypertension. However, its role in the direct detection of ECD requires further validation against established physiological criteria.

Purpose: Neonatal respiratory distress syndrome (NRDS) is a leading cause of morbidity in preterm infants. Existing prenatal tests for fetal lung maturity are either invasive or insufficiently reliable. Microvascular flow imaging (MV-Flow) is a novel Doppler ultrasound technique capable of detecting low-velocity microvascular flow. This study evaluated its utility for visualizing fetal pulmonary microcirculation and predicting NRDS risk.

Methods: A prospective, two-part study was conducted. In part 1, 167 normal singleton pregnancies (12-42 weeks) underwent MV-Flow imaging of the fetal lungs. The vascular intensity of microvascular volume (VIMV) was measured using different regions of interest and compared with conventional Doppler; reproducibility and gestational-age trends were assessed. In part 2, 42 fetuses scanned within 72 hours of delivery were followed postnatally. VIMV values were compared between NRDS and non-NRDS neonates, and logistic regression was used to evaluate predictive value.

Results: MV-Flow successfully visualized fine peripheral lung vessels undetectable by conventional Doppler. VIMV measurements were feasible and highly reproducible (intraclass correlation coefficient >0.92). VIMV increased with gestational age (r≈0.8, P<0.001). Fetuses who developed NRDS had significantly lower VIMV than matched controls (P<0.05). Each 1% increase in VIMV was associated with a 73% (whole lung) or 65% (peripheral lung) reduction in NRDS risk (adjusted odds ratio≈0.3, P<0.005). A low peripheral-lung VIMV, defined by gestational norms, predicted NRDS with 82% sensitivity and 84% specificity.

Conclusion: MV-Flow offers a non-invasive, reproducible method for assessing fetal lung maturity. VIMV correlates with gestational development and may serve as a novel marker for identifying fetuses at risk of NRDS.

Purpose: This study prospectively compared the diagnostic accuracy of vibration-controlled transient elastography (VCTE) and point shear wave elastography (pSWE) in the assessment of liver fibrosis, versus a reference standard of magnetic resonance elastography (MRE).

Methods: This study prospectively enrolled patients with chronic liver disease, who underwent pSWE, VCTE, and MRE. Fibrosis was staged based on liver stiffness (LS) values measured using MRE: F0 (<2.61 kPa), F1 (≥2.61 to <2.97 kPa), F2 (≥2.97 to <3.62 kPa), F3 (≥3.62 to <4.69 kPa), and F4 (≥4.69 kPa). Each modality was performed independently, and the results were blinded to minimize bias. Diagnostic performance was assessed using the Pearson correlation coefficient (CC), Lin concordance correlation coefficient (CCC), area under the receiver operating characteristic curve (AUROC), Obuchowski index, integrated discrimination improvement (IDI), and net reclassification improvement (NRI).

Results: In total, 251 patients (median age, 64 years; 97 women) were evaluated. Both pSWE (CC, 0.838; CCC, 0.825) and VCTE (CC, 0.803; CCC, 0.784) demonstrated strong correlations with MRE, with no statistically significant differences. AUROC values for diagnosing fibrosis stage were comparable between pSWE and VCTE. Based on the Obuchowski index, pSWE provided closer agreement with MRE in detecting ≥F1, ≥F2, and ≥F4. Analyses of IDI and NRI also displayed significantly better agreement between pSWE and MRE in detecting ≥F1, ≥F2, and ≥F4 (NRI: P<0.001; IDI: F1 and F2, P<0.001; F4, P=0.002).

Conclusion: pSWE demonstrated closer alignment than VCTE with LS values measured by MRE, suggesting the potential of pSWE for noninvasively assessing liver fibrosis.

Purpose: This study aimed to compare the clinical and imaging features of hepatocellular carcinomas (HCCs) detected versus undetected on surveillance ultrasound (US), based on a prospective cohort.

Methods: This post-hoc subgroup study analyzed data from MAGNUS-HCC trial, a prospective multicenter study evaluating both biannual US and annual non-contrast abbreviated magnetic resonance imaging (NC-AMRI) for HCC surveillance in high-risk patients. Among 34 HCCs, 16 tumors were detected and 18 tumors were undetected on US. We compared clinical features such as sex, age, body mass index (BMI), liver disease etiology, α-fetoprotein (AFP) level, and Child-Pugh class between participants who were diagnosed on US and those who were not. Imaging features including size, hemiliver distribution, anatomical section, subcapsular location, blind spot location, the presence of hepatic steatosis, and the presence of poor sonic window were also compared. NC-AMRI features were also assessed.

Results: No significant differences were observed between US-detected and US-undetected groups in terms of sex, age, liver disease etiology, AFP level, or Child-Pugh class. Patients with US-undetected HCCs had higher BMI (25.7 vs. 23.8 kg/m2, P=0.049). Lesions in blind spots were significantly more common in the US-undetected group (55.6% vs. 18.8%, P=0.039), as were lesions in the left hemiliver (38.9% vs. 6.3%, P=0.043). No significant differences were found in tumor size, anatomical section, subcapsular location, presence of poor sonic window, presence of hepatic steatosis, or magnetic resonance imaging characteristics. Of the 16 US-detected tumors, 62.5% were hypoechoic and 37.5% were hyperechoic.

Conclusion: US is less effective in detecting HCCs in patients with a higher BMI and tumors located in the blind spots or left hemiliver. These limitations should be considered in planning and interpreting surveillance strategies.

Doppler ultrasound is one of the oldest modalities for measuring and visualizing blood flow. This review paper explores the principles of Doppler ultrasound and blood flow imaging. Following a brief history of Doppler ultrasound, all Doppler modes, including B-Flow imaging, are discussed, with emphasis on spectral broadening and Doppler spectrum amplitude in relation to clinical implications. The paper also outlines sources of uncertainty in Doppler flow measurement. Emerging technologies in blood flow imaging are introduced, including microvascular flow imaging without contrast agents and four-dimensional vascular imaging from a two-dimensional transducer, which have been commercialized within the past decade, as well as row-column array transducer systems, high-frame-rate imaging, and photoacoustic imaging, which remain in preclinical and research stages.

Purpose: Intravascular ultrasound (IVUS) is widely used to visualize vascular structures and assess atherosclerotic plaques, particularly for evaluating the risk of rupture. Although increasing the center frequency of the transducer can enhance spatial resolution, it also increases attenuation, which substantially degrades image quality at greater depths. To mitigate this trade-off, synthetic aperture focusing (SAF) techniques have been studied; however, when applied to single-element rotational IVUS systems, they have yielded only minimal improvements and introduced undesirable artifacts.

Methods: In this work, a directional SAF (dSAF) method is proposed to address these limitations. The convex nature of the point spread function in rotational IVUS scanning is analyzed to track the true direction of echo signals, enabling the selective exclusion of off-axis signals. By focusing only on valid signals during synthesis, resolution degradation and artifact formation are prevented, and the fidelity of the reconstructed image is preserved.

Results: Validation through simulations and phantom experiments indicates that the dSAF method achieves an average 37.3% improvement in lateral resolution and an 8.6% increase in contrast-to-noise ratio, without degrading penetration depth.

Conclusion: These findings suggest that directional echo screening effectively mitigates the limitations encountered with conventional SAF in IVUS imaging, offering a robust pathway to improved image quality. Additionally, the proposed approach can be integrated into existing IVUS workflows, potentially expediting clinical adoption and advancing intravascular diagnostic capabilities.

Purpose: The present study aimed to evaluate changes in renal stiffness in primary hyperparathyroidism (PHPT) using shear-wave elastography (SWE), and to assess treatmentrelated improvements following microwave ablation (MWA).

Methods: This retrospective study included 53 PHPT patients (mean age, 56.4±10.8 years; 48 women, 5 men) and 70 healthy controls (mean age, 54.5±9.7 years; 58 women, 12 men). Baseline renal SWE values (measured in the renal cortex) and biochemical parameters (parathyroid hormone [PTH], calcium, phosphate) were compared between groups. The control group served only for baseline comparisons and was not followed longitudinally. In the patient group, posttreatment SWE and biochemical changes were assessed at 1 day, 1 month, 3 months, 6 months, and 1 year. Statistical analysis included paired and independent t-tests, while regression analysis identified predictors of renal stiffness.

Results: Baseline SWE values were higher in PHPT patients than in controls (9.16±2.64 kPa vs. 5.02±0.63 kPa, P<0.01). After MWA, SWE values significantly decreased (1-year mean, 5.15±1.19 kPa; P<0.01). PTH and calcium levels also improved post-treatment (P<0.01). Regression analysis showed that PTH (β=0.02, P<0.01) and calcium (β=1.82, P=0.018) independently predicted renal stiffness.

Conclusion: Reductions in renal stiffness and improvements in biochemical parameters were observed in PHPT patients following MWA. These preliminary findings suggest that SWE may have potential as a non-invasive tool for assessing and monitoring renal involvement in PHPT.