Ultrasound in Medicine and Biology最新文献

Prostate cancer (PCa) poses a significant threat to men's health, with early diagnosis being crucial for improving prognosis and reducing mortality rates. Transrectal ultrasound (TRUS) plays a vital role in the diagnosis and image-guided intervention of PCa. To facilitate physicians with more accurate and efficient computer-assisted diagnosis and interventions, many image processing algorithms in TRUS have been proposed and achieved state-of-the-art performance in several tasks, including prostate gland segmentation, prostate image registration, PCa classification and detection and interventional needle detection. The rapid development of these algorithms over the past 2 decades necessitates a comprehensive summary. As a consequence, this survey provides a narrative review of this field, outlining the evolution of image processing methods in the context of TRUS image analysis and meanwhile highlighting their relevant contributions. Furthermore, this survey discusses current challenges and suggests future research directions to possibly advance this field further.

Objective: To investigate the relationship between the rim-like enhancement pattern on pre-ablation contrast-enhanced ultrasound (CEUS) of colorectal liver metastasis (CRLM) and the therapeutic efficacy of percutaneous microwave ablation (MWA).

Methods: Patients with CRLM underwent MWA and were evaluated using CEUS before ablation in our hospital between February 2020 and February 2023 were enrolled in this retrospective study. The enhancement patterns of CRLM were assessed by two radiologists and classified as rim-like enhancement and non-rim-like enhancement patterns. The therapeutic outcomes, including cumulative intrahepatic progression rate and early intrahepatic progression rate, were followed up and analyzed.

Results: Overall, 50 patients with 121 nodules were enrolled. Rim-like enhancement pattern was observed in 18 patients (18/50, 36.0%). The cumulative intrahepatic progression rate was significantly higher in the rim-like enhancement group than the rate in the non-rim-like enhancement group (p = 0.022). The early intrahepatic progression rate in the rim-like enhancement group was also significantly higher than the rate in the non-rim-like enhancement group (12/17, 70.6% vs. 6/24, 25.0%, p = 0.005). The multivariable analysis demonstrated that the rim-like enhancement pattern of CRLM was a significant risk factor associated with early intrahepatic progression after MWA (p = 0.013).

Conclusion: Rim-like enhancement pattern on pre-ablation CEUS of CRLM was associated with a higher risk of intrahepatic progression after MWA.

Introduction: Intensive care unit-acquired weakness (ICUAW) is associated with unfavorable outcomes. The current diagnostic tools for ICUAW are invasive, yield delayed results, and lack precision. This study explored the potential of shear wave elastography (SWE), an innovative ultrasound technique, to evaluate the quality changes in the lower extremity muscles of ICU patients, potentially aiding the early detection of ICUAW.

Materials and methods: We included adult patients diagnosed with ICUAW (average Medical Research Council score < 48) from December 2020 to October 2021. ICU patients were continuously monitored twice daily. Using ultrasonography, we measured the thickness (TH), cross-sectional area (CSA), pennation angle (PA), and SWE (SWE-values) modulus of the bilateral rectus femoris (RF) and vastus intermedius (VI). The diagnostic performance of each parameter was evaluated using sensitivity, specificity, and area under the receiver operating characteristic curve.

Results: Ultrasound quantification assessments were performed in 47 patients, 24 with ICUAW and 23 without ICUAW. Notably, PA decreased (RF: 11.33%, VI: 10.51%), while muscle rigidity increased (RF: 22.39%, VI: 22.50%) in ICUAW patients compared with non-ICUAW patients. The sensitivity and specificity for PA in the RF were 79.17% and 91.30%, respectively, and those for PA in VI were 79.17% and 78.26%, respectively. The use of both combinations yielded 91.67% and 73.91% sensitivity and specificity, respectively. Employing the PA of RF and SWE-values of RF together, we observed a diagnostic prediction sensitivity of 91.67% and a specificity of 60.87%.

Conclusions: ICUAW patients exhibited increased rigidity of the lower extremity muscles during their hospital stay. Ultrasonic SWE emerged as a reliable and objective tool, offering significant diagnostic value for ICUAW.

Magnetic nanoparticles (MNPs) have gained significant attention in biomedical engineering and imaging applications due to their unique magnetic and mechanical properties. With their high magnetization and small size, MNPs serve as excitation sources for magnetically heating to destroy tumors (magnetic hyperthermia) and magnetically controlled drug carriers in magnetic drug targeting. However, effectively visualizing the distribution of MNPs during research or potential clinical use with low-cost modalities remains a critical challenge. Although magnetic resonance imaging provides pre- and post-procedural imaging, it is considered to be high cost, and real-time imaging during clinical procedures is limited. In contrast, ultrasound-based imaging methods offer the advantage of providing the potential for immediate feedback during clinical use and are considered to be a low-cost modality. Ultrasound-based imaging techniques, including magnetomotive ultrasound, magnetoacoustic tomography, and thermoacoustic imaging, emerged as promising approaches for imaging the distribution of MNPs. These techniques offer the potential for real-time imaging, facilitating precise therapy monitoring. By exploring the strengths and limitations of various ultrasound-based imaging techniques for MNPs, this review seeks to provide comprehensive insights that can guide researchers in selecting suitable ultrasound-based modalities and inspire further advancements in this exciting field.

Objective: Early detection and monitoring of hepatic steatosis can help establish appropriate preventative measures against progression to more advanced disease. We aimed to develop a deep learning (DL) program for classification of hepatic steatosis from standard-of-care grayscale ultrasound (US) images.

Methods: In this single-center retrospective study, we utilized grayscale US images from January 1, 2010, to October 23, 2022, labeled with magnetic resonance imaging (MRI) proton density fat fraction (MRI-PDFF) to develop a DL multi-instance program for differentiating normal (S0) from steatotic liver (S1/2/3) and normal/mild steatosis (S0/1) from moderate/severe steatosis (S2/3). Diagnostic performances were assessed with area under the receiver operating characteristic curves (AUC), sensitivity, specificity and balanced accuracy with 95% confidence interval (CI).

Results: A total of 403 patients with 403 US exams were included: 171 (42%) were normal (S0: MRI-PDFF <5%), 154 (38%) had mild steatosis (S1: MRI-PDFF 5-17.4%), 29 (7%) had moderate steatosis (S2: MRI-PDFF >17.4%-22.1%) and 49 (12%) had severe steatosis (S3: MRI-PDFF >22.1%). The dataset was split to include 322 patients in train/validation and 81 patients in a holdout test set (kept blind). The S0 versus S1/2/3 model achieved 81.3% (95% CI 72.1-90.5) AUC, 81.1% (70.6-91.6) sensitivity, 71.4% (54.7-88.2) specificity and 76.3% (66.4-86.2) balanced accuracy. The S0/1 versus S2/3 model achieved 95.9% (89-100) AUC, 87.5% (71.3-100) sensitivity, 96.9% (92.7-100) specificity and 92.2% (83.8-100) balanced accuracy. A multi-class model achieved a sensitivity of 71.4% (54.7-88.2) for S0, 67.6% (52.5-82.7) for S1 and 87.5% (71.3-100) for S2/3; specificity for the same model was 81.1% (70.6-91.6) for S0, 77.3% (64.9-89.7) for S1 and 96.9% (92.7-100) for S2/3.

Conclusion: Our DL program offered high sensitivity and accuracy in detecting and categorizing hepatic steatosis from standard-of-care ultrasound.

Objective: Perfluoropropane droplets (PD) are nanometer-sized particles that can be formulated from commercially available contrast agents. The preferential retention of PDs in diseased microvascular beds can be detected by ultrasound imaging techniques after acoustic activation and offers an opportunity for the detection of such processes as scar formation or inflammation. We hypothesized that in the presence of ischemia/reperfusion (I/R) injury, retention of intravenously injected PDs would be enhanced.

Methods: Using an established intravital microscopy model of rat cremaster microcirculation, we determined the retention and subsequent acoustic activation behavior of PDs in exteriorized rat cremaster tissue. DiI-labeled droplets (200 µL) were administered intravenously. Acoustic activation was achieved with a clinical ultrasound system at two ultrasound frequencies (1.5 and 7 MHz).

Results: Fluorescent microbubbles could be detected in the microvasculature after intravenous injection of PDs and subsequent acoustic activation. Increased retention of PDs was observed in the I/R group compared with control group with both ultrasound frequencies (p < 0.05). Using higher-resolution microscopy, we found evidence that some droplets extravasate to the outside of the endothelial border or are potentially engulfed by leukocytes.

Conclusion: Our data indicate that targeted imaging of the developing scar zones might be possible with ultrasound activation of intravenously injected PDs, and a method of targeting therapies to these same regions could be developed.

Objectives: This study aimed to investigate dyssynchronous heart failure in fetuses of mothers with diabetes mellitus (FDM) and fetal controls (FC) using two-dimensional speckle tracking echocardiography (2D-STE) and novel M-mode prototype software (PS).

Methods: In this cohort study 174 fetuses were analyzed, 87 in the FDM-cohort and 87 gestational age-matched fetuses in the FC-cohort. A subgroup of 38 fetuses formed the final case group, with a high median frame rate of approximately 160 frames/s. Using 2D Cardiac Performance Analysis software (TOMTEC, Unterschleissheim, Germany) we measured global longitudinal strain (GLS). TOMTEC PS detected annular displacement by assessing an artificial M-mode on the previously generated tracking. Dyssynchrony (DYS) was calculated as the inter- and intraventricular difference in time to peak GLS or annular displacement.

Results: Greater DYS was observed in all basal myocardial measurement sites and software between FDM-cohort compared to FC-cohort and no significant correlation was found between DYS measurements and gestational age. Intraventricular DYS between the basal segments was statistically significant (all p ≤ 0.036, Wald test of univariate regression models). The PS performed best in DYS measurements identifying right ventricular DYS as potentially predicting FDM (FDM: median, 18.5 (interquartile range [IQR], 13.9-25.0) ms vs. FC: median, 2.7 [IQR, 1.5-3.5] ms; p < 0.001).

Conclusion: Increased intraventricular DYS demonstrated an impact of maternal diabetes mellitus on fetal hearts independent of gestational age. The prototype M-mode method identified cardiac dysfunction with higher accuracy than the conventional analysis. High-quality echocardiographic image acquisition is imperative for clinical application of 2D-STE and related advanced technologies.