Journal of Medical Ultrasonics最新文献

Purpose: To observe and measure the levator aponeurosis (LA) in patients with unilateral aponeurotic ptosis (AP) using high-frequency (22 MHz) B-mode ultrasound with a water balloon.

Methods: Thirty-two unilateral APs were recruited. Palpebral fissure height (PFH), levator function (LF), and marginal reflex distance 1 (MRD1) of the affected eyes and the normal control eyes were measured. Sagittal ultrasound images of the central upper eyelid of both eyes were captured, and ultrasound indicators such as the thickness of the LA, the distance from the upper border of the tarsal plate to the septoaponeurosis junction (TJD), the thickness of the tarsal plate (TTP), the height of the tarsal plate (HTP), and the distance from the insertion point of the LA to the lower border of the tarsal plate (ITD) were measured in the ultrasound images.

Results: The PFH, LF, MRD1, and thickness of the LA were all significantly lower in the affected eyes compared to the normal control eyes. The TJD value in the affected eyes was significantly greater than that in the normal control eyes. In contrast, the other three measurement parameters-namely, TTP, HTP, and ITD-showed no significant intergroup differences.

Conclusions: High-frequency (22 MHz) B-mode ultrasound is a noninvasive and highly effective tool for visualizing and measuring the LA. In cases of unilateral AP, the LA exhibits reduced thickness compared to that of normal control eyes.

Purpose: To investigate the value of dynamic contrast-enhanced ultrasound (DCE-US) analysis using the Liver Imaging Reporting and Data System (LI-RADS) to improve the diagnosis of hepatocellular carcinoma (HCC).

Methods: This multicenter study retrospectively enrolled consecutive high-risk patients for HCC who underwent contrast-enhanced ultrasound (CEUS) between December 2022 and June 2023. Quantitative CEUS analysis was performed using VueBox^® to obtain diagnostic parameters for HCC. These parameters were used as auxiliary indicators to reassign the LI-RADS categories. The reference standard was pathologic confirmation or composite criteria. The diagnostic performance of LI-RADS with and without quantitative DCE-US parameters was assessed.

Results: 269 patients (median age, 61 years [interquartile range, 52-69]; 206 men, 63 women) with 269 focal liver lesions (FLLs) (median size, 40 mm [interquartile range, 25-62 mm]) were included. Among the 269 FLLs, 227 were HCC, 31 non-HCC malignancies, and 11 benign lesions. DCE-US analysis showed HCC had higher rise time (RT) and fall time (FT) at the lesion margin than non-HCC malignancies (both P < 0.05) but lower RT and FT than benign lesions (both P < 0.05). RT at the lesion margin (range 17.48 s-21.16 s) serves as an auxiliary indicator for HCC diagnosis. Compared to CEUS LI-RADS, the revised LR-5 improved sensitivity (61.7 vs. 52.8%, P < 0.001) without a significant decrease in specificity (76.2 vs. 83.3%, P = 0.25) for diagnosing HCC.

Conclusion: DCE-US quantitative analysis improved the sensitivity for HCC diagnosis without affecting specificity, thereby optimizing the diagnostic performance of CEUS LI-RADS.

Purpose: This study aimed to assess the dynamics of the distance between the talus and lateral malleolus during the stance phase of gait and confirm any sex differences.

Methods: The distance between the talus and lateral malleolus was quantified during gait in 25 healthy participants. Noninvasive ultrasound with three-dimensional motion analysis was used to assess the kinematic properties during the walking stance phase.

Results: The distance between the talus and lateral malleolus widened immediately after initial contact, narrowed during mid-stance, and widened during the stance cycle in all participants. The distance was significantly wider in females, especially during the early and terminal stance phases, contributing to differences in sagittal mobility.

Conclusions: Quantitative measurement of the anterior talofibular ligament attachment distance may aid in the early detection of ankle abnormalities. The dynamic characteristics observed in females during gait may be associated with chronic ankle instability or osteoarthritis risk.

Purpose: Minimum variance (MV) beamforming was introduced in ultrasound imaging to improve image quality. It solves a minimization problem where the closed-form solution imposes huge computational load due to the matrix inversion requirement. The MV problem can be iteratively solved to avoid this requirement.

Methods: This paper shows that the weight vector at the first iteration is proportional to the covariance matrix elements. It is proposed that this proportionality be considered as a constraint in the main MV problem. Inspired by the idea of the exact line search method, solving the proposed constrained MV (CMV) problem leads to an adaptive beamforming with considerably lower computational load. As an interesting point, the unknown coefficients can be directly calculated through entries of a covariance matrix by a simple operation.

Result: The proposed method was investigated on several simulation and experimental data sets. It was found that it required 93% fewer flops than the MV method, which represents a dramatic computational gain.

Conclusion: This study showed how only two features, the mean and trace of the covariance matrix, are enough to achieve adaptive beamforming. The proposed beamformer provides approximately the same resolution as the MV method.

Purpose: This study aimed to objectively and quantitatively analyze fetal motor behavior using DeepLabCut (DLC), a markerless posture estimation tool based on deep learning, applied to four-dimensional ultrasound (4DUS) data collected during the second trimester. We propose a novel clinical method for precise assessment of fetal neurodevelopment.

Methods: Fifty 4DUS video recordings of normal singleton fetuses aged 12 to 22 gestational weeks were analyzed. Eight fetal joints were manually labeled in 2% of each video to train a customized DLC model. The model's accuracy was evaluated using likelihood scores. Intra- and inter-rater reliability of manual labeling were assessed using intraclass correlation coefficients (ICC). Angular velocity time series derived from joint coordinates were analyzed to quantify fetal movement patterns and developmental coordination.

Results: Manual labeling demonstrated excellent reproducibility (inter-rater ICC = 0.990, intra-rater ICC = 0.961). The trained DLC model achieved a mean likelihood score of 0.960, confirming high tracking accuracy. Kinematic analysis revealed developmental trends: localized rapid limb movements were common at 12-13 weeks; movements became more coordinated and systemic by 18-20 weeks, reflecting advancing neuromuscular maturation. Although a modest increase in tracking accuracy was observed with gestational age, this trend did not reach statistical significance (p < 0.001).

Conclusion: DLC enables precise quantitative analysis of fetal motor behavior from 4DUS recordings. This AI-driven approach offers a promising, noninvasive alternative to conventional qualitative assessments, providing detailed insights into early fetal neurodevelopmental trajectories and potential early screening for neurodevelopmental disorders.

Purpose: Criteria for diagnosing fetal growth restriction (FGR) vary globally. The Japanese criterion is estimated fetal weight (EFW) below - 1.5 standard deviations, without distinctions based on gestational age or severity. However, some international diagnostic criteria classify FGR using gestational age, Doppler assessments, and growth. While the Japanese criterion is simple and easy to apply, including EFW, gestational age at diagnosis, growth, and Doppler findings can provide a more comprehensive assessment of fetoplacental function. The aims of this study were: [1] to reclassify small fetuses on the Japanese criterion into early FGR, late FGR, or small for gestational age (SGA) groups by applying Doppler-inclusive diagnostic criteria, and [2] compare the perinatal outcomes.

Methods: In this retrospective study, FGR diagnosed based on the Japanese criterion between 2017 and 2021 at our hospital were reclassified into early FGR, late FGR, or SGA by applying Doppler-inclusive criteria. Cases not classified as early or late FGR were categorized as SGA. Perinatal, maternal, and neonatal outcomes were analyzed across all groups.

Results: Overall, 184 growth-restricted fetuses based on the Japanese criterion-160 cases (42 early FGR, 51 late FGR, and 67 SGA)-were enrolled after excluding 24 cases of fetal malformation. Gestational age at delivery, mode of delivery, and maternal and neonatal complications differed significantly among the groups. The early FGR group showed a significantly higher incidence of preterm birth, emergent Cesarean section, and severe maternal or neonatal complications.

Conclusions: FGR with Doppler-inclusive criteria can be better for practical use providing high relevance to perinatal outcome.