Continuous Shear Wave Elastography for Liver Using Frame-to-Frame Equalization of Complex Amplitude.

This study addresses a crucial necessity in the field of noninvasive liver fibrosis diagnosis by introducing the concept of continuous shear wave elastography (C-SWE), utilizing an external vibration source and color Doppler imaging. However, an application of C-SWE to assess liver elasticity, a deep region within the human body, arises an issue of signal instability in the obtained data. To tackle this challenge, this work proposes a method involving the acquisition of multiple frames of datasets, which are subsequently compressed. Furthermore, the proposed frame-to-frame equalization method compensates discrepancies in the initial phase that might exist among multiple-frame datasets, thereby significantly enhancing signal stability. The experimental validation of this approach encompasses both phantom tests and in vivo experiments. In the phantom tests, the proposed technique is validated through a comparison with the established shear wave elastography (SWE) technique. The results demonstrate a remarkable agreement, with an error in shear wave velocity of less than 4.2%. Additionally, the efficacy of the proposed method is confirmed through in vivo tests. As a result, the stabilization of observed shear waves using the frame-to-frame equalization technique exhibits promising potential for accurately assessing human liver elasticity. These findings collectively underscore the viability of C-SWE as a potential diagnostic instrument for liver fibrosis.

Multivariable Quantitative US Parameters for Assessing Hepatic Steatosis.

Background Because of the global increase in the incidence of nonalcoholic fatty liver disease, the development of noninvasive, widely available, and highly accurate methods for assessing hepatic steatosis is necessary. Purpose To evaluate the performance of models with different combinations of quantitative US parameters for their ability to predict at least 5% steatosis in patients with chronic liver disease (CLD) as defined using MRI proton density fat fraction (PDFF). Materials and Methods Patients with CLD were enrolled in this prospective multicenter study between February 2020 and April 2021. Integrated backscatter coefficient (IBSC), signal-to-noise ratio (SNR), and US-guided attenuation parameter (UGAP) were measured in all participants. Participant MRI PDFF value was used to define at least 5% steatosis. Four models based on different combinations of US parameters were created: model 1 (UGAP alone), model 2 (UGAP with IBSC), model 3 (UGAP with SNR), and model 4 (UGAP with IBSC and SNR). Diagnostic performance of all models was assessed using area under the receiver operating characteristic curve (AUC). The model was internally validated using 1000 bootstrap samples. Results A total of 582 participants were included in this study (median age, 64 years; IQR, 52-72 years; 274 female participants). There were 364 participants in the steatosis group and 218 in the nonsteatosis group. The AUC values for steatosis diagnosis in models 1-4 were 0.92, 0.93, 0.95, and 0.96, respectively. The C-indexes of models adjusted by the bootstrap method were 0.92, 0.93, 0.95, and 0.96, respectively. Compared with other models, models 3 and 4 demonstrated improved discrimination of at least 5% steatosis (P < .01). Conclusion A model built using the quantitative US parameters UGAP, IBSC, and SNR could accurately discriminate at least 5% steatosis in patients with CLD. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Han in this issue.

Comparison of modified CEUS LI-RADS with sonazoid and CT/MRI LI-RADS for diagnosis of hepatocellular carcinoma.

AIM: To compare the diagnostic performance based on the modified CEUS Liver Imaging Reporting and Data System (LI-RADS), which includes Kupffer-phase findings as a major imaging feature, with that of CT and MRI (CT/MRI) LI-RADS for liver nodules in patients at high risk of HCC. METHODS: A total of 120 patients with 120 nodules were included in this retrospective study. The median size of the lesions was 20.0 mm (interquartile range, 14.0-30.8 mm). Of these lesions, 90.0% (108 of 120) were confirmed as HCCs, 6.7% (8 of 120) were intrahepatic cholangiocarcinomas, 1.7% (2 of 120) were metastases, and 1.7% (2 of 120) were dysplastic nodules. All nodules were diagnosed histopathologically. Each nodule was categorized according to the modified CEUS LI-RADS and CT/MRI LI-RADS version 2018. The diagnostic performance and inter-modality agreement of each criterion was compared. RESULTS: The inter-modality agreement for the modified CEUS LI-RADS and CT/MRI LI-RADS was slight agreement (kappa = 0.139, p = 0.015). The diagnostic accuracies of HCCs for the modified CEUS LR-5 and CT/MRI LR-5 were 70.0% (95% confidence interval [CI]: 61.0%, 78.0%) versus 70.8% (95% CI: 61.8%, 78.8%) (p = 0.876), respectively. The diagnostic accuracies of non-HCC malignancies for the modified CEUS LR-M and CT/MRI LR-M were 84.2% (95% CI: 76.4%, 90.2%) versus 96.7% (95% CI: 91.7%, 99.1%) (p = 0.002), respectively. CONCLUSIONS: The diagnostic performance for HCCs on the modified CEUS LR-5 and CT/MRI LR-5 are comparable. In contrast, CT/MRI LR-M has better diagnostic performance for non-HCC malignancy than that of the modified CEUS LR-M.

Liver stiffness does not affect ultrasound-guided attenuation coefficient measurement in the evaluation of hepatic steatosis.

AIM: Recently, a new method has been developed to diagnose hepatic steatosis with attenuation coefficients based on the ultrasound-guided attenuation parameter (UGAP). We investigated whether fibrosis identified by hepatic stiffness measurements based on magnetic resonance elastography (MRE) affects attenuation coefficient measurement using UGAP for the evaluation of hepatic steatosis. METHODS: A total of 608 patients with chronic liver disease were analyzed. Correlations between magnetic resonance imaging-determined proton density fat fraction (PDFF) or MRE value and attenuation coefficients were evaluated. In addition, the interaction between hepatic fibrosis and the attenuation coefficient was analyzed. RESULTS: The correlation coefficient (r) between PDFF values and attenuation coefficient values was 0.724, indicating a strong relationship. Conversely, the r between MRE values and attenuation coefficient values was -0.187, indicating almost no relationship. In the multiple regression assessment of the effect of PDFF and MRE on the attenuation coefficient based on UGAP, the P-values for PDFF, MRE, and PDFF × MRE were < 0.001, 0.277, and 0.903, respectively. In patients with non-alcoholic fatty liver disease (n = 169), the r between PDFF values and attenuation coefficient values was 0.695, indicating a moderate relationship. Conversely, the r between MRE values and attenuation coefficient values was -0.068, indicating almost no relationship. In the multiple regression assessment of the effect of PDFF and MRE on the attenuation coefficient based on UGAP, the P-values for PDFF, MRE, and PDFF × MRE were <0.001, 0.948, and 0.706, respectively. CONCLUSION: UGAP-determined attenuation coefficient was weakly affected by liver stiffness, an indicator of hepatic fibrosis.

Utility of Attenuation Coefficient Measurement Using an Ultrasound-Guided Attenuation Parameter for Evaluation of Hepatic Steatosis: Comparison With MRI-Determined Proton Density Fat Fraction.

OBJECTIVE: Recently, a new method was developed to diagnose hepatic steatosis by measuring attenuation coefficients that are based on the ultrasound-guided attenuation parameter (UGAP). We investigated the diagnostic ability of these coefficients to detect steatosis that was identified using the proton density fat fraction (PDFF) on MRI in patients with chronic liver disease. MATERIALS AND METHODS: A total of 126 patients with chronic liver disease (non-hepatitis B, non-hepatitis C) were analyzed. The diagnostic ability of UGAP-determined attenuation coefficients was evaluated using ROC curve analysis, and the correlation between MRI-determined PDFF values and attenuation coefficient values was determined. RESULTS: The correlation coefficient (r) between PDFF values and attenuation coefficient values was 0.746 (95% CI, 0.657-0.815) (p < 0.001), corresponding to a strong relationship. The diagnostic ability of attenuation coefficients for steatosis grades ≥ 1, ≥ 2, and 3 as determined by PDFF were 0.922 (95% CI, 0.870-0.973), 0.874 (95% CI, 0.814-0.934), and 0.892 (95% CI, 0.835-0.949), respectively. The r between PDFF values and attenuation coefficient values was 0.559 (95% CI, 0.391-0.705) (p < 0.001) in patients with mild or no steatosis (grade ≤ 1). In addition, the r between PDFF values and attenuation coefficient values was 0.773 (95% CI, 0.657-0.853) (p < 0.001) in obese patients (body mass index [weight in kilograms divided by the square of height in meters] ≥ 25). The diagnostic ability of attenuation coefficients for patients with steatosis grades ≥ 1, ≥ 2, and 3 as determined by PDFF were 0.884 (95% CI, 0.792-0.976), 0.863 (95% CI, 0.778-0.947), and 0.889 (95% CI, 0.813-0.965), respectively. CONCLUSION: UGAP-determined attenuation coefficient values had a good diagnostic ability to detect hepatic steatosis.

Accuracy of 2D shear wave elastography in the diagnosis of liver fibrosis in patients with chronic hepatitis C.

PURPOSE: This prospective study was conducted to assess the diagnostic accuracy of two-dimensional shear wave elastography (2D SWE) in the diagnosis of liver fibrosis in patients with chronic liver disease and hepatitis C virus (HCV) compared with the serum liver fibrosis biomarkers using the results of liver biopsy as the reference standard. METHODS: We analyzed 233 consecutive HCV patients. On the same day, 2D SWE m, biochemical tests, and liver biopsy were performed. We used the METAVIR staging system and receiver operating characteristic curves for the analysis. RESULTS: The success rate of 2D-SWE was 98.7%. The median shear wave velocities (SWVs) of patients in the F0, F1, F2, F3, and F4 stages were 1.35 m/s, 1.42 m/s, 1.58 m/s, 1.83 m/s, and 2.13 m/s, respectively, demonstrating a stepwise increase (P < .0001). The accuracy of 2D-SWE in the prediction of ≥F1, ≥F2, ≥F3, and F4 was .888 (95% CI: .85-.93), .915 (95% CI: .88-095), .940 (95% CI: .91-.97), and .949 (95% CI: .92-.97), respectively. 2D-SWE was significantly superior to serum liver fibrosis biomarkers. CONCLUSION: 2D-SWE was positively correlated with the severity of liver fibrosis and was more useful for to predict all liver fibrosis grades in HCV patients than liver fibrosis biomarkers.

Deep learning approach for discrimination of liver lesions using nine time-phase images of contrast-enhanced ultrasound.

PURPOSE: Contrast-enhanced ultrasound (CEUS) shows different enhancement patterns depending on the time after administration of the contrast agent. The aim of this study was to evaluate the diagnostic performance of liver nodule characterization using our proposed deep learning model with input of nine CEUS images. METHODS: A total of 181 liver lesions (48 benign, 78 hepatocellular carcinoma (HCC), and 55 non-HCC malignant) were included in this prospective study. CEUS were performed using the contrast agent Sonazoid, and in addition to B-mode images before injection, image clips were stored every minute up to 10 min. A deep learning model was developed by arranging three ResNet50 transfer learning models in parallel. This proposed model allowed inputting up to nine datasets of different phases of CEUS and performing image augmentation of nine images synchronously. Using the results, the correct prediction rate, sensitivity, and specificity between "benign" and "malignant" cases were analyzed for each combination of the time phase. These accuracy values were also compared with the washout score judged by a human. RESULTS: The proposed model showed performance superior to the referential standard model when the dataset from B-mode to the 10-min images were used (sensitivity: 93.2%, specificity: 65.3%, average correct answer rate: 60.1%). It also maintained 90.2% sensitivity and 61.2% specificity even when the dataset was limited to 2 min after injection, and this accuracy was equivalent to or better than human scoring by experts. CONCLUSION: Our proposed model has the potential to identify tumor types earlier than the Kupffer phase, but at the same time, machine learning confirmed that Kupffer-phase Sonazoid images contain essential information for the classification of liver nodules.

Application of a quality threshold to improve liver shear wave elastography measurements in free-breathing pediatric patients.

PURPOSE: This study assessed the benefits of quality threshold (QT) implementation for liver shear wave elastography (SWE) in children during free breathing. METHODS: The QT, which adjusts the SWE map display based on shear wave quality, was set at 55%. Phantom measurements (PMs) were taken with a fixed probe using QT (termed PM-1); a moving probe without QT (PM-2); and a moving probe with QT (PM-3). Each measurement was subjected to random samplings of various sizes. Clinical measurements (CMs) were obtained from children with biliary atresia using following protocols: CM-1, manually defined regions of interest (ROIs); CM-2, default ROIs without QT; and CM-3, default ROIs with QT. Elasticity measurements were compared across fibrosis grades, and color patterns on the SWE maps were analyzed. RESULTS: In the phantom experiments, the moving probe produced lower elasticity measurements; this difference decreased upon QT application. With the moving probe, random sampling indicated fewer interquartile range-to-median ratios exceeding 30% upon QT application (4% vs. 14% when five values were sampled, P=0.004). In clinical experiments, QT improved the differentiation of fibrosis grade in patients over 5 years old, with a significant difference between moderate and severe fibrosis (P=0.004). Elasticity variability was positively correlated with fibrosis grade (τ=0.376, P<0.001). Certain apparent errors, termed artificial stripe patterns, were not eliminated by QT. CONCLUSION: Applying QT to exclude low-quality pixels can minimize measurement error and improve differentiation of liver fibrosis grades. The presence of an artificial stripe pattern on the SWE map may indicate images requiring exclusion.

Hepatocellular carcinoma treated with sorafenib: early detection of treatment response and major adverse events by contrast-enhanced US.

BACKGROUND & AIMS: Early prediction of tumour response and major adverse events (AEs), especially liver failure, in patients with hepatocellular carcinoma (HCC) is essential for maximizing the clinical benefits of sorafenib. To evaluate the usefulness of dynamic contrast-enhanced ultrasound (DCE-US) for the early prediction of tumour response and major AEs in HCC patients. METHODS: Thirty-seven HCC patients were started on a reduced dosage of sorafenib, subsequently increased to the standard dosage. Tumour response at 1 month was assessed by CT using the Response Evaluation Criteria in Solid Tumors (RECIST). Major AEs were defined as grade 3 or higher. DCE-US was performed before treatment (day 0) and on days 7, 14 and 28. Changes in perfusion parameters in the tumour and liver parenchyma between day 0 and later time points were compared between treatment responders and nonresponders based on RECIST and between patients who experienced major AEs and those who did not. Tumour results were also compared with progression-free survival (PFS) and overall survival (OS). RESULTS: Tumour perfusion parameters based on the area under the time-intensity curve (AUC) were statistically significant, with AUC during washin on day 14, the most relevant for tumour response (P = 0.0016) and AUC during washin on day 7, the most relevant for both PFS (P = 0.009) and OS (P = 0.037). A decrease in total AUC between days 0 and 7 in the liver parenchyma was strongly correlated with major AEs (P = 0.0002). CONCLUSION: DCE-US may be useful for the early prediction of tumour response and major AEs in patients with HCC.

Contrast-enhanced ultrasonography using Sonazoid(®) is useful for diagnosis of malignant ovarian tumors: comparison with Doppler ultrasound.

PURPOSE: The purpose of this study was to assess the usefulness of Sonazoid(®)-enhanced ultrasonography (US) in the diagnosis of ovarian cancer in comparison with Doppler US. METHODS: Twenty-five ovarian tumor patients who were scheduled to undergo surgery were recruited for this study. The day before the operation, each patient was evaluated with color and power Doppler and baseline US during intravenous infusion of Sonazoid. Each lesion was classified as "benign" or "malignant" on the basis of specific criteria for a Doppler signal or Sonazoid-enhanced pattern. The reference standard was the histology of surgically removed adnexal tumors. RESULTS: Twenty patients were diagnosed with malignant tumors (invasive cancer, n = 15; metastatic cancer, n = 1; borderline tumor, n = 4), and the remaining five were diagnosed with benign tumors. Sonazoid-enhanced US correctly depicted the presence or absence of intratumoral blood flow in all patients with an accuracy of 92 %. Color Doppler ultrasound depicted the malignancies with an accuracy of 64 %, and power Doppler ultrasound depicted them with an accuracy of 76 %. CONCLUSION: Our study suggests that Sonazoid-enhanced US is superior to conventional color Doppler US for the diagnosis of malignant ovarian tumors, but not to power Doppler US. The data and their interpretation in our study should be taken with some degree of caution because of the small number of subjects. Further studies involving a larger sample size would be needed to confirm these findings.

Modified CEUS LI-RADS using Sonazoid for the diagnosis of hepatocellular carcinoma.

This review outlines several modified versions of the contrast-enhanced ultrasonography Liver Imaging Reporting and Data System (CEUS LI-RADS) that utilize Sonazoid. Furthermore, it discusses the advantages and challenges of diagnosing hepatocellular carcinoma using these guidelines, as well as the authors' expectations and opinions regarding the next CEUS LI-RADS version. It is possible that Sonazoid could be incorporated into the next version of CEUS LI-RADS.

Quantification in molecular ultrasound imaging: a comparative study in mice between healthy liver and a human hepatocellular carcinoma xenograft.

OBJECTIVES: The purpose of this study was to quantitatively assess the contrast kinetics of vascular endothelial growth factor receptor 2 (VEGFR2)-targeted microbubbles (BR55; Bracco Suisse, Geneva, Switzerland) compared to clinically used microbubbles (SonoVue; Bracco SpA, Milan, Italy) in both normal liver and human hepatocellular carcinoma xenograft tumors in mice. METHODS: Microbubbles were injected intravenously into healthy mice (n = 5) and mice bearing hepatocellular carcinoma xenograft tumors (n = 10). Cine loops of contrast enhancement in normal liver and the tumors were acquired for 10 minutes. Quantitative perfusion parameters were derived by fitting time-intensity curves using a dedicated mathematical model combining a bolus function and a ramp function. Immunohistochemical examinations were also performed for normal liver and tumor specimens to determine the level of VEGFR2 expression. RESULTS: The peak contrast enhancement observed in normal liver with BR55 was comparable to that with SonoVue, whereas a significant difference was observed in latephase enhancement at 10 minutes (ramp slope: P < .01). In the tumor model, SonoVue was rapidly cleared from the circulation, without any noticeable binding in the tumor, whereas BR55 showed a gradual decline, resulting in a longer wash-out period (mean transit time: P < .01). Immunohistochemical examinations showed that intratumoral vascular endothelial cells had sparse and weak VEGFR2 expression, whereas the sinusoidal capillaries in normal liver had much more diffuse and much stronger expression. CONCLUSIONS: Our results suggest that BR55 accurately reflects the VEGFR2 status in human hepatocellular carcinoma xenograft tumors. We showed that quantification applied to molecular ultrasound imaging may provide an objective method for measuring the degree of microbubble binding.

Usefulness of arrival time parametric imaging in evaluating the degree of liver disease progression in chronic hepatitis C infection.

OBJECTIVE: To determine whether the degree of liver disease progression in chronic hepatitis C infection can be evaluated by arrival time parametric imaging using contrast-enhanced sonography with Sonazoid (perfluorobutane; GE Healthcare, Oslo, Norway). METHODS: In this study, 60 patients with liver disease in chronic hepatitis C infection were examined and compared with 10 healthy volunteers who served as controls. A recommended dose of the sonographic contrast agent Sonazoid was intravenously infused, and the S5 or S6 region of the liver and right kidney were observed concurrently while movies of the procedure were saved. Arrival time parametric images of liver parenchymal blood flow were created, with red pixels to indicate an arrival time of 0 to 5 seconds and yellow pixels to indicate an arrival time of 5 to 10 seconds. From the obtained images, the ratio of the red area to the entire enhanced area of the liver was calculated using image-processing software. Each participant was subsequently subjected to liver biopsy for liver fibrosis staging according to Metavir scores, and the determined fibrosis stage was compared with the ratio of red. The serum albumin level, platelet count, and prothrombin time were also compared with the ratio of red for each participant. RESULTS: The ratio of red increased significantly as liver fibrosis stage advanced (P < .01 for F1 versus F2; P < .01 for F1 versus F3; P < .01 for F1 versus F4; and P < .01 for F2 versus F4). As the ratio of red increased, significant decreases were observed in the serum albumin level (r = -0.29; P = .027), platelet count (r = -0.46; P = .0003), and prothrombin time (r = -0.46; P = .0002). CONCLUSIONS: Arrival time parametric imaging using Sonazoid-enhanced sonography enables noninvasive evaluation of the degree of progression of liver disease in chronic hepatitis C infection and is thus considered clinically useful.

The Mechanisms Underlying Vertical Artifacts in Lung Ultrasound and Their Proper Utilization for the Evaluation of Cardiogenic Pulmonary Edema.

The recent advances in lung ultrasound for the diagnosis of cardiogenic pulmonary edema are outstanding; however, the mechanism of vertical artifacts known as B-lines used for the diagnosis has not yet been fully elucidated. The theory of "acoustic trap" is useful when considering the generation of vertical artifacts. Basic research in several studies supports the theory. Published studies with pilot experiments indicate that clarification of the relationship between the length and intensity of vertical artifacts and physical or acoustic composition of sources may be useful for differentiating cardiogenic pulmonary edema from lung diseases. There is no international consensus with regard to the optimal settings of ultrasound machines even though their contribution to the configuration of vertical artifacts is evident. In the clinical setting, the configuration is detrimentally affected by the use of spatial compound imaging, the placement of the focal point at a deep level, and the use of multiple focus. Simple educational materials using a glass microscope slide also show the non-negligible impact of the ultrasound machine settings on the morphology of vertical artifacts.

The effect of attenuation inside the acoustic traps on the configuration of vertical artifacts in lung ultrasound: an experimental study with simple models.

PURPOSE: Using simple experimental models for lung ultrasound, we evaluated the relationship of the attenuation inside the sources of vertical artifacts to the echo intensity and attenuation of artifacts. METHODS: As sources of artifacts, we made 10 different hemispherical gel objects with two different mediums (pure agar or agar containing graphite with an attenuation coefficient of 0.5 dB/cm · MHz) and five different diameters (3.6, 5.6, 7.5, 9.5, or 11.4 mm). Ten of each hemispherical gel object were prepared for the statistical analyses. Each object was placed onto a chest wall phantom as the plane of the hemisphere was placed in an upward position. The echo intensity and attenuation of the artifact generated from each object was measured and compared. RESULTS: For all sizes, the intensity and attenuation of the artifacts in the objects made of agar containing graphite were significantly lower and larger, respectively, than those in the objects made of pure agar. In the objects containing graphite, the intensity decreased when the frequency was changed from 5 to 9 MHz. CONCLUSION: Based on this experiment, assessing the intensity and attenuation of vertical artifacts may help estimate the physical composition of sources of vertical artifacts in lung ultrasound.

Attenuation Coefficient Measurement Using a High-Frequency (2-9 MHz) Convex Transducer for Children Including Fatty Liver.

We evaluated the measurement feasibility and diagnostic ability of an ultrasound-guided attenuation parameter (UGAP) using a high-frequency convex transducer in children. This retrospective study included all consecutive children who underwent abdomen ultrasonography from July to December 2020. Attenuation coefficients (ACs) of the liver were measured using both 1- to 6-MHz (AC1-6) and 2- to 9-MHz (AC2-9) probes of the LOGIQ E10 system (GE Healthcare). t-Tests and Pearson's or partial correlation analyses were performed, and AC cutoff values for diagnosing fatty liver were obtained from receiver operating characteristic curve analyses. Finally, 118 patients (M:F = 83:35, mean age: 10.2 ± 4.1 y) were evaluated, and the measurement success rate was 98.3% (116/118) for AC2-9. AC1-6 was available in children with a liver depth greater than 9 cm. The ratio of interquartile range to median of the AC2-9 was lower than that of the AC1-6 (4.3 vs. 8.5, p < 0.001). In the normal group (n = 41), the AC2-9 values were not associated with age, sex or body mass index. For the evaluation of steatosis, the AC2-9 values exhibited a positive correlation with the MR fat fraction (coefficient = 0.498, p < 0.001). The cutoff value of 0.699 dB/cm/MHz had 90.2% sensitivity and 100% specificity for diagnosing fatty liver. In conclusion, measurements of ACs using a high-frequency convex transducer are feasible even in small children, with lower measurement variability. The AC2-9 values also had good diagnostic performance for pediatric fatty liver.

Noninvasive Diagnosis of Hepatocellular Carcinoma on Sonazoid-Enhanced US: Value of the Kupffer Phase.

The aim of this study was to compare the diagnostic performance of Contrast-Enhanced US Liver Imaging Reporting and Data System (CEUS LI-RADS) version 2017, which includes portal- and late-phase washout as a major imaging feature, with that of modified CEUS LI-RADS, which includes Kupffer-phase findings as a major imaging feature. Participants at risk of hepatocellular carcinoma (HCC) with treatment-naïve hepatic lesions (≥1 cm) were recruited and underwent Sonazoid-enhanced US. Arterial phase hyperenhancement (APHE), washout time, and echogenicity in the Kupffer phase were evaluated using both criteria. The diagnostic performance of both criteria was analyzed using the McNemar test. The evaluation was performed on 102 participants with 102 lesions (HCCs (n = 52), non-HCC malignancies (n = 36), and benign (n = 14)). Among 52 HCCs, non-rim APHE was observed in 92.3% (48 of 52). By 5 min, 73.1% (38 of 52) of HCCs showed mild washout, while by 10 min or in the Kupffer phase, 90.4% (47 of 52) of HCCs showed hypoenhancement. The sensitivity (67.3%; 35 of 52; 95% CI: 52.9%, 79.7%) of modified CEUS LI-RADS criteria was higher than that of CEUS LI-RADS criteria (51.9%; 27 of 52; 95% CI: 37.6%, 66.0%) (p = 0.0047). In conclusion, non-rim APHE with hypoenhancement in the Kupffer phase on Sonazoid-enhanced US is a feasible criterion for diagnosing HCC.

Diagnosis of hepatic hemangioma by parametric imaging using sonazoid-enhanced US.

BACKGROUND/AIMS: Comparison of Parametric Imaging (PI) using Sonazoid-enhanced ultrasonography (US) and microflow imaging (MFI) to determine the possibility of hepatic hemangioma diagnosis using PI. METHODOLOGY: Twenty-two hepatic hemangioma nodules (mean±SD diameter: 31.6±19.1mm) undergoing Sonazoid-enhanced US between February 2008 and March 2009. After Sonazoid-enhanced US, COMMUNE ultrasonographic image analysis software was used for analysis of tumor imaging dynamics in the vascular phase using PI and MFI. In PI, 0s was set as the time contrast agent reached the tumor. Imaging within the tumor after 0s was color-coded according to time, and the images were displayed in color. In MFI, 0s was set as the time contrast agent reached the tumor. The path of microbubbles as it flowed through blood vessels was superimposed on the original B-mode images. Three trained physicians used these methods to analyze tumor imaging dynamics. RESULTS: All physicians concluded all cases were hepatic hemangioma regardless of method used. However, compared to MFI, PI allowed determination of more detailed blood flow dynamics in high-flow hepatic hemangioma, where blood flow speed was faster than in normal hepatic hemangioma. CONCLUSIONS: It is possible to diagnose hepatic hemangioma using PI using sonazoid-enhanced US.

Simple Experimental Models for Elucidating the Mechanism Underlying Vertical Artifacts in Lung Ultrasound: Tools for Revisiting B-Lines.

Using simple experimental models, we evaluated the generation, configuration and echo intensity of vertical artifacts by varying the point or plane of contact and height of objects that correspond to sources of vertical artifacts in the subpleural space. We used an ultrasound gel spot to imitate the source and a block of bacon as a chest wall phantom. As the size of the point of contact between the gel spot on the polypropylene sheet and the phantom decreased by peeling the sheet, a vertical artifact measuring ≤1 cm was generated and/or extended deeper, finally reaching 10 cm in depth. Next, objects of different shapes made using gel balls were used to observe the generation of artifacts and measure and compare the echo intensity. For a given shape, the intensity was markedly higher in one model with the point of contact than in the other model with the plane of contact. With the same point or plane of contact, the echo intensity was higher in the taller model. The size of the point or plane of contact and height of the source were observed to be key factors in the generation, length and echo intensity of the artifacts.