Coronavirus disease 2019 (COVID‐19) represents a very heterogeneous disease. Some aspects of COVID‐19 pneumonia question the real nature of ground glass opacities and its consolidative lesions. It ...has been hypothesized that COVID‐19 lung involvement could represent not only a viral effect but also an immune response induced by the infection, causing epithelial/endothelial lesions and coagulation disorders. We report 3 cases of COVID‐19 pneumonia in which contrast‐enhanced ultrasound was suggestive of consolidations with perfusion defects, at least in part caused by ischemic or necrotic changes and not only by inflammatory or atelectasis events.
The capacity of contrast-enhanced ultrasound (CEUS) to detect microvessel perfusion has received much attention in cancer imaging since it can be used to evaluate the enhancement patterns of the ...lesions during all vascular phases in real time, with higher temporal resolution as compared other imaging modalities. A rich body of literature has demonstrated the potential usefulness of CEUS in the assessment of HCC in response to both locoregional and systemic therapies. It is useful to evaluate the efficacy of ablation immediately after treatment to provide guidance for the retreatment of residual unablated tumors. In patients treated with transarterial chemoembolization (TACE), CEUS showed a high degree of concordance with computed tomography and magnetic resonance for the differentiation of responders from non-responders. Dynamic CEUS (D-CEUS) has emerged as a promising tool for the depicting changes in tumor perfusion during anti-angiogenetic treatment that can be associated with tumor response and clinical outcome. This article provides a general review of the current literature regarding the usefulness of CEUS in monitoring HCC response to therapy, highlighting the role of the procedure in different stages of the disease.
The aim of this article is to provide an inventory of the use of contrast‐enhanced ultrasound (CEUS) in relation to percutaneous interventional procedures. The article is structured into a systematic ...literature review followed by a clinical part relating to percutaneous CEUS‐guided procedures. A literature search identified 3109 records. After screening, 55 articles were analyzed and supplemented with pictorial material to explain the techniques. In conclusion, the best‐evidenced indications for CEUS‐guided interventions are biopsy and ablation of inconspicuous or B‐mode–invisible tumors, intraprocedural ablation control and follow‐up, as well as percutaneous transhepatic cholangiography and drainage procedures.
Objectives
To conduct a quantitative analysis of renal microvascular perfusion in diabetic patients with kidney injury using contrast‐enhanced ultrasound (CEUS).
Methods
A total of 172 patients with ...type 2 diabetes mellitus and kidney injury were recruited from May 2017 to November 2019. After collection of clinical characteristics, a CEUS examination was performed after injection of the contrast agent SonoVue (Bracco SpA, Milan, Italy). Time‐intensity curves and renal perfusion parameters were analyzed. Ultrasound‐guided renal biopsy was performed. The patients were divided into a diabetic nephropathy (DN) group and a nondiabetic renal disease (NDRD) group according to renal pathologic results. The discrimination of perfusion parameters between the groups was analyzed statistically with SPSS version 19.0 software (IBM Corporation, Armonk, NY). Receiver operating characteristic curves were used to illustrate the diagnostic performance of indicators.
Results
Ninety‐eight patients, including 45 with DN (29 male; mean age ± SD, 57.76 ± 10.47 years) and 53 with NDRD (40 male; mean age, 48.7 ± 13.88 years) were included in this study. The peak enhancement (PE), wash‐in the area under the curve (AUC), wash‐in rate, wash‐in perfusion index, wash‐out AUC, wash‐in and wash‐out AUC, and wash‐out rate were significantly different between the groups (P < .05). There were no differences in time‐related parameters between the DN and NDRD groups (P > .05). The receiver operating characteristic curve analysis showed that the AUC for PE was 0.727, and PE lower than 7712.426 had diagnostic potential, with sensitivity of 81% and specificity of 40% in discriminating between NDRD and DN.
Conclusions
The quantification of CEUS parameters can discriminate DN in diabetic patients with kidney injury. The PE and AUC may be feasible parameters.
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Objectives
Uterine fibroids are common findings in women with pelvic pain and abnormal uterine bleeding. The reference standard test in the pretreatment evaluation of fibroids is contrast‐enhanced ...magnetic resonance (MR) imaging. This study compared the number, size, location, and enhancement of uterine fibroids identified by contrast‐enhanced ultrasound (CEUS) and MR. The aim of this study was to demonstrate that CEUS performs similarly to MR and could be used as an alternative imaging modality.
Methods
In this prospective observational study, 26 women underwent transabdominal CEUS and MR examinations. Blinded to the original clinical MR interpretations, 2 readers reviewed the MR and CEUS studies for each patient. The number, size, location, and enhancement of each fibroid per patient were reported by MR and CEUS. A Pearson correlation coefficient was calculated for the number of fibroids identified by each modality.
Results
In total, 126 fibroids were imaged: 115 (91.3%) were observed on both examinations; 9 (7.1%) were observed by MR only; and 2 (1.6%) were observed by CEUS only. A high correlation was found between the modalities for the number of fibroids identified per patient (r = 0.97; P < .001). There was also no significant difference between the modalities for each patient in the fibroid number, size, location, or enhancement.
Conclusions
These findings suggest that transabdominal CEUS may represent an alternative to MR in pretreatment evaluation of uterine fibroids and could serve as a test of choice in patients with a contraindication to MR.
Shell‐stabilized gas microbubbles (MB) and nanobubbles (NB) are frequently used for biomedical ultrasound imaging and therapeutic applications. While it is widely recognized that monodisperse bubbles ...can be more effective in these applications, the efficient formulation of uniform bubbles at high concentrations is difficult to achieve. Here, it is demonstrated that a standard mini‐extruder setup, commonly used to make vesicles or liposomes, can be used to quickly and efficiently generate monodisperse NBs with high yield. In this highly reproducible technique, the NBs obtained have an average diameter of 0.16 ± 0.05 µm and concentration of 6.2 ± 1.8 × 1010 NBs mL−1 compared to 0.32 ± 0.1 µm and 3.2 ± 0.7 × 1011 mL−1 for NBs made using mechanical agitation. Parameters affecting the extrusion and NB generation process including the temperature, concentration of the lipid solution, and the number of passages through the extruder are also examined. Moreover, it is demonstrated that extruded NBs show a strong acoustic response in vitro and a strong and persistent US signal enhancement under nonlinear contrast enhanced ultrasound imaging in mice. The extrusion process is a new, efficient, and scalable technique that can be used to easily produce high yield smaller monodispersed nanobubbles.
Shell‐stabilized, gas nanobubbles are used in a variety of biomedical and industrial applications, but are difficult to make. Here a high yield, scalable method for direct production of monodisperse lipid‐shelled C3F8 nanobubbles for biomedical applications via a simple extrusion process is presented. Compared to self‐assembly via mechanical agitation, the process is efficient, and requires no postprocessing for size isolation.
Purpose
Contrast‐enhanced ultrasound (CEUS) by injection of microbubbles (MBs) has shown promise as a cost‐effective imaging modality for prostate cancer (PCa) detection. More recently, nanobubbles ...(NBs) have been proposed as novel ultrasound contrast agents. Unlike MBs, which are intravascular ultrasound contrast agents, the smaller diameter of NBs allows them to cross the vessel wall and target specific receptors on cancer cells such as the prostate‐specific membrane antigen (PSMA). It has been demonstrated that PSMA‐targeted NBs can bind to the receptors of PCa cells and show a prolonged retention effect in dual‐tumor mice models. However, the analysis of the prolonged retention effect has so far been limited to qualitative or semi‐quantitative approaches.
Methods
This work introduces two pharmacokinetics models for quantitative analysis of time–intensity curves (TICs) obtained from the CEUS loops. The first model is based on describing the vascular input by the modified local density random walk (mLDRW) model and independently interprets TICs from each tumor lesion. Differently, the second model is based on the reference‐tissue model, previously proposed in the context of nuclear imaging, and describes the binding kinetics of an indicator in a target tissue by using a reference tissue where binding does not occur.
Results
Our results show that four estimated parameters, β, β/λ$\beta /\lambda $, β+/β−${\beta }_ + /{\beta }_ - $, for the mLDRW‐input model, and γ for the reference‐based model, were significantly different (p‐value <0.05) between free NBs and PSMA‐NBs. These parameters estimated by the two models demonstrate different behaviors between PSMA‐targeted and free NBs.
Conclusions
These promising results encourage further quantitative analysis of targeted NBs for improved cancer diagnostics and characterization.
Objectives
The purpose of this study was to quantify contrast‐enhanced ultrasound enhancement of focal fatty sparing (FFS) and focal fatty infiltration (FFI) and compare it with adjacent liver ...parenchyma.
Methods
This was a retrospective observational study yielding 42 cases in the last 4 years. Inclusion criteria were a focal liver lesion, adequate video availability, and an established diagnosis of FFS or FFI based on clinical or imaging follow‐up or a second modality. Contrast‐enhanced ultrasound examinations were performed with a standard low–mechanical index technique. Commercially available software calculated quantitative parameters for a focal liver lesion and a reference area of liver parenchyma, producing relative indices.
Results
In total, 42 patients were analyzed (19 male) with a median age of 18 (interquartile range, 42) years and a median lesion diameter of 30 (interquartile range, 16) mm. The cohort included 26 with FFS and 16 with FFI. Subjectively assessed, 27% of FFS and 25% of FFI were hypoenhancing in the arterial phase, and 73% of FFS and 75% of FFI were isoenhancing. In the venous and delayed phases, all lesions were isoenhancing. The peak enhancement (P = .001), wash‐in area under the curve (P < .01), wash‐in rate (P = .023), and wash‐in perfusion index (P = .001) were significantly lower in FFS compared with adjacent parenchyma but not the mean transit time. In the FFI subgroup, no significant difference was detected. Comparing relative parameters, only the wash‐in rate was significantly (P = .049) lower in FFS than FFI. The mean follow‐up was 2.8 years.
Conclusions
Focal fatty sparing shows significantly lower and slower enhancement than the liver parenchyma, whereas FFI enhances identically. Focal fatty sparing had a significantly slower enhancement than FFI.
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•The LR-5 CEUS class is an optimal diagnostic tool for HCC.•The other LR classes (LR-3, LR-4 and LR-M) require histological confirmation.•These data could change the diagnostic ...algorithm of HCC.
The use of contrast enhanced ultrasound (CEUS) for the diagnosis of hepatocellular carcinoma (HCC) in cirrhosis was questioned because of the risk of a false positive diagnosis in cases of cholangiocarcinoma. The American College of Radiology has recently released a scheme (CEUS Liver Imaging Reporting and Data System LI-RADS®) to classify lesions at risk of HCC investigated by CEUS. The aim of the present study was to validate this LI-RADS scheme for the diagnosis of HCC.
A total of 1,006 nodules from 848 patients with chronic liver disease at risk of HCC were collected in five Italian centers and retrospectively analyzed. Nodules were classified as LR-5, (HCC) if ≥1 cm with arterial phase hyperenhancement, and late washout (onset ≥60 s after contrast injection) of mild degree. Rim enhancement and/or early and/or marked washout qualified lesions as LR-M (malignant, but not specific for HCC). Other combinations qualified lesions at intermediate risk for HCC (LR-3) or probable HCC (LR-4). Diagnostic reference standard was CT/MRI diagnosis of HCC (n = 506) or histology (n = 500).
The median nodule size was 2 cm. Of 1,006 nodules, 820 (81%) were HCC, 40 (4%) were cholangiocarcinoma, 116 (11%) regenerative nodules (±dysplastic). The LR-5 category (52% of all nodules) was 98.5% predictive of HCC, with no risk of misdiagnosis for pure cholangiocarcinoma. Sensitivity for HCC was 62%. All LR-M nodules were malignant and the majority of non-hepatocellular origin. Over 75% of cholangiocarcinomas were LR-M. The LR-3 category included 203 lesions (HCC 96 47%) and the LR-4 202 (HCC 173 87%).
The CEUS LI-RADS class LR-5 is highly specific for HCC, enabling its use for a confident non-invasive diagnosis.
This is a retrospective study of approximately 1,000 focal lesions at risk for hepatocellular carcinoma (HCC). Herein, we demonstrate that the refined definition of the typical contrast enhanced ultrasound pattern of HCC introduced by the Liver Imaging Reporting and Data System (LI-RADS®) practically abolishes the risk of misdiagnosis of other malignant entities (e.g. cholangiocarcinoma) for HCC with negligible reduction in sensitivity. These data support the use of contrast enhanced ultrasound to diagnose HCC in cirrhosis.
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