Contrast-enhanced Ultrasound Research Articles

Alterations in Regional Brain Microcirculation in Patients with Sepsis: A Prospective Study Using Contrast-Enhanced Brain Ultrasound.

Alterations in regional brain microcirculation have not been well studied in patients with sepsis. Regional brain microcirculation can be studied using contrast-enhanced brain ultrasound (CEUS) with microbubble administration. CEUS was used to assess alterations in regional brain microcirculation on 3 consecutive days in 58 patients with sepsis and within 24h of intensive care unit admission in 10 aged-matched nonseptic postoperative patients. Time-intensity perfusion curve variables (time-to-peak and peak intensity) were measured in different regions of interest of the brain parenchyma. The mean arterial pressure, cardiac index (using transthoracic echocardiography), global cerebral blood flow (using echo-color Doppler of the carotid and vertebral arteries), mean flow velocities of the middle cerebral arteries, and brain autoregulation (using transcranial echo-color Doppler) were measured simultaneously. The presence of structural brain injury in patients with sepsis was confirmed on computed tomography imaging, and encephalopathy, including coma and delirium, was evaluated using the Glasgow Coma Scale and the Confusion Assessment Method in the Intensive Care Unit. Of the 58 patients with sepsis, 42 (72%) developed acute encephalopathy and 11 (19%) had some form of structural brain injury. Brain autoregulation was impaired in 23 (40%) of the patients with sepsis. Brain microcirculation alterations were observed in the left lentiform nucleus and left white matter of the temporoparietal region of the middle cerebral artery in the sepsis nonsurvivors but not in the survivors or postoperative patients. The alterations were characterized by prolonged time-to-peak (p < 0.01) and decreased peak intensity (p < 0.01) on the time-intensity perfusion curve. Prolonged time-to-peak but not decreased peak intensity was independently associated with worse outcome (p = 0.03) but not with the development of encephalopathy (p = 0.77). Alterations in regional brain microcirculation are present in critically ill patients with sepsis and are associated with poor outcome. Trial registration Registered retrospectively on December 19, 2019.

Contrast-Enhanced Intraoperative Ultrasound Shows Excellent Performance in Improving Intraoperative Decision-Making.

The aim of this study was to evaluate the performance and the impact of contrast-enhanced intraoperative ultrasound (CE-IOUS) on intraoperative decision-making, as there is still no standardized protocol for its use. Therefore, we retrospectively analyzed multiple CE-IOUS performed in hepato-pancreatic-biliary surgery with respect to pre- and postoperative imaging and histopathological findings. Data of 50 patients who underwent hepato-pancreatic-biliary surgery between 03/2022 and 03/2024 were retrospectively collected. CE-IOUS was performed with a linear 6-9 MHz multifrequency probe connected to a high-resolution device. The ultrasound contrast agent used was a stabilized aqueous suspension of sulphur hexafluoride microbubbles. In total, all 50 lesions indicated for surgery were correctly identified. In 30 cases, CE-IOUS was used to localize the primary lesion and to define the resection margins. In the remaining 20 cases, CE-IOUS identified an additional lesion. Fifteen of these findings were identified as malignant. In eight of these cases, the additional malignant lesion was subsequently resected. In the remaining seven cases, CE-IOUS again revealed an inoperable situation. In summary, CE-IOUS diagnostics resulted in a high correct classification rate of 95.7%, with positive and negative predictive values of 95.2% and 100.0%, respectively. CE-IOUS shows excellent performance in describing intraoperative findings in hepato-pancreatic-biliary surgery, leading to a substantial impact on intraoperative decision-making.

Development of a Polymer Ultrasound Contrast Agent Incorporating Nested Carbon Nanodots

Polymer microbubbles have garnered broad interest as potential theranostic agents. However, the capabilities of polymer MBs can be greatly enhanced, particularly regarding the imaging performance and functional versatility of the platform. This study investigates integrating fluorescent carbon nanodots within polylactic acid (PLA) microbubbles. First, the formulations are characterized by their size, microbubble counts, zeta potential, and resonance frequency. Then, the fluorescence capabilities, nanoparticle loading, and acoustic capabilities are examined. Unmodified (U-), carboxylated (C-), and aminated graphene quantum dots (A-GQDs) were separately suspended and synthesized at a 2% w/w ratio with PLA in the organic phase of the water/oil/water double emulsion process. The new microbubbles were characterized using an AccuSizer, Zetasizer, scanning electron microscopy, fluorescence microscopy and fluorimetry, a custom-built acoustic setup, and clinical ultrasound. The GQD microbubbles were sized between 1.4 and 1.9 µm (U = 1.90, C = 1.44, A = 1.72, Unloaded = 2.02 µm). The U-GQD microbubble exhibited a higher bubble concentration/mg PLA ( p &lt; .05) and the A-GQD microbubbles exhibited the greatest shift in zeta potential. Electron microscopy revealed smooth surfaces and a spherical shape, showing that the nanoparticle addition was not deleterious. The A-GQD microbubbles were specifically detectable using DAPI-filtering with fluorescence microscopy and had the highest TRITC-filtered fluorescence. The C-GQD microbubbles had the highest loading efficiency at 59.4% ( p &lt; .05), and the lowest max acoustic enhancement at 5 MHz (U = 19.8, C = 17.6, A = 18.9, Unloaded = 18.5 dB; p &lt; .05). Additionally, all microbubbles were visible and susceptible to inertial cavitation utilizing clinical ultrasound. The A-GQDs showed promise toward improving the theranostic capabilities of the microbubble platform. They have imbued the most advantageous fluorescence capability and slightly improved backscatter enhancement while retaining all the necessary capabilities of an ultrasound contrast agent. Future studies will investigate the coloading potential of A-GQDs and drug within microbubbles.

Correction: Principle of contrast-enhanced ultrasonography

Correction: Principle of contrast-enhanced ultrasonography

Ultrasound Multimodality Examination Improves the Diagnostic Efficiency of Non-Mass-Like Breast Lesions

This study is focused on ultrasound multimodality examination, which refers to the combined use of three ultrasound examination modalities, ultrasound (US), acoustic radiation force impulse (ARFI) imaging, and contrast-enhanced ultrasound (CEUS). The purpose of this study is to analyze the value of applying ultrasound multimodality examination in the differential diagnosis of benign and malignant breast non-mass-like lesions (NMLs). Cases of breast NMLs were analyzed retrospectively, and the nature of all the lesions was verified by pathological examination. Based on the gray-scale ultrasound image characteristics, the cases were classified into types Ⅰ to Ⅴ, and type Ⅰ and type Ⅱ were further classified into 4 subtypes, Ⅰa, Ⅰb, Ⅱa, and Ⅱb, according to whether there was also calcification, and the proportion of malignant cases in each subtype was statistically analyzed. Logistic regression models of US, US+ARFI, US+CEUS, and US+ARFI+CEUS for the diagnosis of malignant cases were established, ROC curves were drawn, the area under the curve (AUC) was calculated, and comparisons were made accordingly. The detection rate of malignant NMLs without calcification (atypical malignant NMLs) by the combination examination of US, ARFI, and CEUS was analyzed. A total of 407 cases were included in the study. All subjects were female, aged 22 to 81 years, with the average age being (47.0±11.0) years. There were 220 benign cases and 187 malignant cases. Ranked from the highest to the lowest, the malignancy proportion of the different types was Ⅰb>Ⅱb>Ⅲ>Ⅴ>Ⅰa>Ⅱa>Ⅳ. The malignant proportion of the low echo area with calcification was significantly higher than that of the lesions without calcification. The AUC (95% confidence interval [CI]) for diagnosing malignant cases with the logistic regression models of US, US+ARFI, US+CEUS, and US+ARFI+CEUS were 0.895 (0.862-0.927), 0.908 (0.878-0.937), 0.921 (0.893-0.948), and 0.927 (0.902-0.952), respectively. Comparison of the AUC of the 4 regression models showed significant differences (P<0.001). The detection rate of US for NMLs without calcification was 80.7%. When US was used in combination with ARFI and CEUS, 86.4% of the malignant NMLs lesions without calcification could be detected if the lesion CEUS score was 4 or 5 points or if shear-wave velocity (SWV)≥4.28 m/s. Breast NMLs with calcification show high risks of malignancy, and a pathological examination is always recommended for a conclusive diagnosis. Ultrasound multimodality examination can improve the diagnostic accuracy of breast NML without calcification.

A Comparative Study of SonoVue and Sonazoid for Contrast-Enhanced Ultrasound CT/MRI Fusion Guidance During Radiofrequency Ablation of Poorly Visualized Hepatic Malignancies: A Prospective Intra-Individual Analysis

PurposeThis study aimed to evaluate the effectiveness of two contrast agents, SonoVue (SV) and Sonazoid (SZ), by comparing them intra-individually in contrast-enhanced ultrasound (CEUS)-CT/MRI fusion imaging (FI) to improve the visibility of inconspicuous liver malignancies on B-mode sonography for guiding percutaneous radiofrequency ablation (RFA). Additionally, the radiologists' preference between SonoVue- CT/MRI FI (SV-FI) and Sonazoid-CT/MRI FI (SZ-FI) was determined. MethodsThis prospective study enrolled 23 patients with inconspicuous hepatic malignancies (≤ 3 cm) on B-mode US who underwent both SV-FI and SZ-FI for RFA guidance. The patients underwent real-time CEUS FI with CT/MRI on the same day, utilizing both SV and SZ with at least 15-min intervals. Tumor visibility and radiologists' preferences were assessed and graded using a 4-point scale during the dynamic phases of both SV-FI and SZ-FI and the Kupffer phase of SZ-FI. ResultsThe tumor visibility scores obtained from CEUS-CT/MRI FI were significantly better than those obtained from US-FI. Indeed, SV-FI and SZ-FI demonstrated comparable visibility scores when corresponding phases were compared (p > 0.05). However, the Kupffer phase images of SZ-FI displayed superior visibility scores (3.70 ± 0.56 vs. 2.96 ± 0.88; p = 0.002) than the late vascular phase images of SV-FI. The radiologists favored SZ-FI in many cases, exhibiting moderate inter-observer agreement (Kappa value = 0.587; 95% CI, 0.403–0.772). ConclusionAlthough CEUS-CT/MRI FI with either SV or SZ substantially improved the visibility of inconspicuous tumors on US-CT/MRI FI, radiologists preferred SZ to SV to guide the RFA procedure.

Peak enhancement in contrast-enhanced ultrasound for assessing endoscopic disease activity in patients with Crohn's disease: a meta-analysis.

Contrast-enhanced ultrasound (CEUS) has been proposed as a valuable tool for detecting disease activity in patients with Crohn's disease (CD). However, previous studies have utilized different parameters, leading to variation in clinical assessment of this technique. To assess the effectiveness of peak enhancement (PE) in CEUS for evaluating endoscopic disease activity in patients with CD. Articles were obtained by searching PubMed, Embase, Web of Science, Wanfang, and CNKI databases. Only studies that investigated the effectiveness of PE in CEUS to discriminate endoscopic disease activity in patients with CD were considered. Pooled sensitivity and specificity were then calculated using a random effects model. Overall, seven studies were included. The endoscopic disease activity of CD was determined based on the simple endoscopic score for Crohn's disease and Crohn's Disease Endoscopic Index of Severity scores. Pooled results showed that a high PE was associated with increased detection efficacy for endoscopic disease activity in CD. Pooled sensitivity, specificity, and positive and negative likelihood ratios were 0.88 (95% confidence interval [CI] = 0.71-0.96), 0.88 (95% CI = 0.81-0.93), 7.60 (95% CI = 4.61-12.53), and 0.14 (95% CI = 0.05-0.35), respectively. The pooled receiver operating characteristic was 0.90 (95% CI = 0.87-0.92), suggesting a good discriminating efficacy of PE in CEUS for endoscopic disease activity of patients with CD. A high PE in CEUS displayed substantial distinguishing accuracy for assessing endoscopic disease activity of patients with CD.

Pulsed focused ultrasound ablation assisted by a surface modified catheter for thrombolysis: a feasibility study

Interventional procedures for the recanalization of blood vessels to treat deep vein thrombosis carry a high risk of vessel wall injuries or hemorrhaging. Focused ultrasound (FUS) has been used to non-invasively break down blood clots that occlude the vessels in both in vitro and in vivo studies. Previous studies have either used thrombolytic drugs or ultrasound contrast agents (e.g., microbubbles) in combination with FUS. Several studies have applied very high peak-negative-pressures (PNP) during FUS treatment to achieve successful thrombolysis without the use of contrast agents. In the current study, we demonstrated that cavitation activity could be significantly enhanced by placing a nitinol wire, whose surface was roughed by laser etching, in the focal region of a FUS field. We demonstrated in vitro in a mock thrombosis that the thrombolysis efficacy of a 500 kHz FUS transducer was significantly enhanced using a surface-etched nitinol wire as compared to an unetched nitinol wire, whereas FUS-alone at the same pressure level did not result in any thrombolysis. These results suggest that a surface modified nitinol catheter exposed to FUS can result in intense cavitation activities leading to enhanced thrombolysis without the use of additional pharmacological or contrast agents.

Local powers of least‐squares‐based test for panel fractional Ornstein–Uhlenbeck process

In recent years, significant advancements have been made in the field of identifying financial asset price bubbles, particularly through the development of time‐series unit‐root tests featuring fractionally integrated errors and panel unit‐root tests. This study introduces an innovative approach for assessing the sign of the persistence parameter () within a panel fractional Ornstein‐Uhlenbeck process, based on the least squares estimator of . This method incorporates three distinct test statistics based on the Hurst parameter (), which can take values in the range of , be equal to , or fall within the interval of . The null hypothesis corresponds to . Based on a panel of continuous records of observations, the null asymptotic distributions are obtained when the time span () is fixed and the number of cross sections () goes to infinity. The power function of the tests is obtained under the local alternative where is close to zero in the order of . This alternative covers the departure from the unit root hypothesis from the explosive side, enabling the calculation of lower power in bubble tests. The hypothesis testing problem and the local power function are also considered when a panel of discrete‐sampled observations is available under a sequential limit, that is, the sampling interval shrinks to zero followed by the goes to infinity.

Ultrasomics differentiation of malignant and benign focal liver lesions based on contrast-enhanced ultrasound

ObjectivesTo establish a nomogram for differentiating malignant and benign focal liver lesions (FLLs) using ultrasomics features derived from contrast-enhanced ultrasound (CEUS).Methods527 patients were retrospectively enrolled. On the training cohort, ultrasomics features were extracted from CEUS and b-mode ultrasound (BUS). Automatic feature selection and model development were performed using the Ultrasomics-Platform software, outputting the corresponding ultrasomics scores. A nomogram based on the ultrasomics scores from artery phase (AP), portal venous phase (PVP) and delayed phase (DP) of CEUS, and clinical factors were established. On the validation cohort, the diagnostic performance of the nomogram was assessed and compared with seniorexpert and resident radiologists.ResultsIn the training cohort, the AP, PVP and DP scores exhibited better differential performance than BUS score, with area under the curve (AUC) of 84.1-85.1% compared with the BUS (74.6%, P < 0.05). In the validation cohort, the AUC of combined nomogram and expert was significantly higher than that of the resident (91.4% vs. 89.5% vs. 79.3%, P < 0.05). The combined nomogram had a comparable sensitivity with the expert and resident (95.2% vs. 98.4% vs. 97.6%), while the expert had a higher specificity than the nomogram and the resident (80.6% vs. 72.2% vs. 61.1%, P = 0.205).ConclusionsA CEUS ultrasomics based nomogram had an expert level performance in FLL characterization.

Contrast media viscosity and its potential effect on the diagnosis of vesicoureteral reflux in children.

To confirm that contrast-enhanced voiding cystourosonography (ceVUS) diagnoses more vesicoureteral reflux (VUR) than voiding cystourethrography (VCUG) and assess whether this could be explained by contrast agent viscosity differences. Children addressed for a VCUG for suspected or known VUR between April 2021 and June 2023 were prospectively included. CeVUS and VCUG were consecutively performed during the same procedure by two operators; for each pelviureteric unit (PUU), VUR presence was assessed and scored (I-V scale). At least 6 months later, three radiologists reassessed VUR grading on all ceVUS static images. The viscosity of the two contrast agents and of the urine were measured at 25 °C and 37 °C. Wilcoxon tests were used for comparisons and linear Cohen's Kappa coefficient for Interobserver and Intraobserver agreement. Eighty-nine children, representing 192 PUU, were included. VUR was detected in 54 PUUs by at least one technique, by both in 30/54, by ceVUS only in 21/54 (38.8%), and by VCUG only in 3/54 (5.5%). VUR grade was higher with ceVUS in 19/30 (63.3%, p < 0.0008) PUUs. The ceVUS agent viscosity at 25 °C/37 °C (1.13 cP/1.03 cP) was almost identical to urine viscosity (1.14 cP/1.02 cP) and it was respectively 8 and 6 times lower than VCUG contrast agent viscosity (9.44 cP/6.03 cP). The Cohen's kappa for ceVUS grading was between 0.75-0.97 (interobserver) and 0.93-0.98 (intraobserver). Our study confirms that ceVUS detects more VUR and grades them higher in comparison to VCUG in children. This could be explained by the lower viscosity of the US contrast agent. Question Why are there differences in detecting and grading VUR between ceVUS and VCUG? Finding VUR was detected by ceVUS or VCUG only in, respectively 38.8% and 5.5% of PUUs. VUR grade was higher with ceVUS in 63.3%. Clinical relevance The higher detection rate and grading of vesicoureteral reflux in children by ceVUS might be explained by the lower viscosity of its sonographic contrast agent. CeVUS might reproduce the urine movement in the urinary tract.

Incorporation of pre- and intra-operative sentinel lymph node mapping techniques in dogs with apocrine gland anal sac adenocarcinoma

The high incidence of nodal metastasis, variable lymphatic drainage patterns, and prognostic significance of nodal metastasis in dogs with apocrine gland anal sac adenocarcinoma (AGASACA) highlight the need for development of standardized techniques for lymph node staging in canine AGASACA. The aim of this study was to develop and describe the utility of pre- and intra-operative sentinel lymph node (SLN) mapping techniques for subsequent nodal extirpation and histologic assessment in dogs with AGASACA. A prospective clinical trial was performed as a pilot study. Eight client-owned dogs with unilateral AGASACA were enrolled. Preoperative contrast-enhanced ultrasound (CEUS) via transrectal ultrasound (TRUS) and CT-lymphography (CTL) was followed by intraoperative SLN mapping within 7 days utilizing a visible dye (methylene blue [MB]) and a near-infrared (NIR) fluorescent dye (indocyanine green [ICG]) with subsequent nodal extirpation and routine anal sacculectomy. In all dogs, preoperative CTL and intraoperative SLN mapping identified at least one SLN. Pre- and intra-operative findings differed in 4/8 dogs. Preoperative CEUS identified a SLN in 7/8 dogs, but the exact location of the SLN was indeterminate. Extirpated lymph nodes were metastatic in 2/8 dogs. Preoperative CTL and intraoperative MB and ICG were an effective combination of SLN mapping techniques in dogs with AGASACA. These techniques each provided unique advantages. Combined, they identified and guided extirpation of early metastatic lymph nodes. Large-scale, prospective studies utilizing the techniques described are needed to accurately determine the incidence and significance of early/occult nodal metastasis in canine AGASACA.

The Role of Contrast-enhanced Ultrasound in the Femoral Head Perfusion Evaluation: A Pilot Study

ObjectivesWe explored the value of contrast-enhanced ultrasound (CEUS) in evaluating femoral head (FH) perfusion, guiding interventions and follow-up for infants with developmental dysplasia of the hip (DDH) and septic arthritis of the hip (SAH). The aim was to provide robust evidence for clinical assessment. MethodsTen infants, including 7 with DDH and 3 with SAH, were prospectively enrolled, with their bilateral hips alternately scanned during the CEUS exams. Twenty hips were classified into the case group (n = 11) and the control group (n = 9). Pre- and post-interventional studies were performed in DDH infants requiring interventions. FH perfusion was assessed by the perfusion area ratio (PAR) and quadrant location of microbubble-defect regions. ResultsIn the case group, 25 CEUS studies were conducted, including 11 baseline, 7 follow-up and 7 post-intervention studies. The PAR significantly decreased in the case group (49.79% vs. 100.00%, p < 0.05). The microbubble-defect regions averagely affected 2 quadrants, primarily quadrat No. 3 (30%) and No. 4 (32%). Seven hip abduction angle adjustments were made based on pre-interventional studies, resulting in a significant increase in PAR in post-interventional studies (37.63% vs. 60.24%, p < 0.05). PAR increased in follow-up studies compared to baseline values (45.61% vs. 76.07%, p < 0.05). The inter- and intra-observer reproducibility of PAR measurements were excellent (intraclass correlation coefficient, both 0.97). ConclusionCEUS proves to be a promising technique for quantitatively detecting FH perfusion in DDH and SAH infants with high reproducibility. It is valuable for baseline, intra-intervention and follow-up studies, aiming in clinical conditions and therapeutic effect evaluation.

Late Hepatocellular Carcinoma Occurrence in Patients Achieving Sustained Virological Response After Direct-Acting Antiviral Therapy: A Matter of Follow-Up or Something Else?

Background: Despite achieving a sustained virological response (SVR) with direct-acting antivirals (DAAs), an unexpected increase in the occurrence rate of hepatocellular carcinoma (HCC) has been observed among HCV-treated patients. This study aims to assess the long-term follow-up of HCV patients treated with DAAs who achieved an SVR to investigate the potential for late-onset HCC. Methods: In this prospective multicenter study, we enrolled consecutive HCV patients treated with DAAs following Italian ministerial guidelines between 2015 and 2018. Exclusion criteria included active HCC on imaging, prior HCC treatment, HBV or HIV co-infection, or liver transplant recipients. Monthly follow-ups occurred during treatment, with subsequent assessments every 3 months for at least 48 months. Abdominal ultrasound (US) was performed within two weeks before starting antiviral therapy, supplemented by contrast-enhanced ultrasonography (CEUS), dynamic computed tomography (CT), or magnetic resonance imaging (MRI) to evaluate incidental liver lesions. Results: Of the 306 patients completing the 48-months follow-up post-treatment (median age 67 years, 55% male), all achieved an SVR. A sofosbuvir-based regimen was administered to 72.5% of patients, while 20% received ribavirin. During follow-up, late-onset HCC developed in 20 patients (cumulative incidence rate of 6.55%). The pattern of HCC occurrence varied (median diameter 24 mm). Multivariate and univariate analyses identified liver stiffness, diabetes, body mass index, and platelet levels before antiviral therapy as associated factors for late HCC occurrence. Conclusions: Our findings suggest that late HCC occurrence may persist despite achieving SVR. Therefore, comprehensive long-term follow-up, including clinical, laboratory, and expert ultrasonography evaluations, is crucial for all HCV patients treated with DAAs.

Diffuse large B-cell lymphoma of the gallbladder with hepatoduodenal invasion exhibiting a necrotic tendency.

We report a case of diffuse large B-cell lymphoma (DLBCL) of the gallbladder with extensive hepatoduodenal invasion, which was challenging to diagnose histologically due to a strong tendency to be necrotic. An 71year-old man presented with upper abdominal pain and was referred to our hospital. Computed tomography revealed a distended gallbladder with air within the irregular gallbladder wall and an indistinct border with the hepatoduodenum, suggesting invasion. Esophagogastroduodenoscopy detected an ulceration in the duodenal bulb. However, histologic analysis failed to provide a definitive diagnosis due to the presence of necrotic tissue. Furthermore, direct biopsy from the gallbladder mucosa by endoscopic retrograde cholangiography revealed only necrotic tissue and no diagnosis. Contrast ultrasonography for the hepatic invasion revealed enhancement with blood flow, suggesting non-necrotic tissue. Subsequently, an ultrasound-guided core-needle biopsy was conducted to obtain tissue samples from the described lesion. The pathology showed atypical lymphocytes with irregular nuclei. Immunostaining indicated positive expression of CD10, CD20, Bcl-6, and C-Myc, consistent with a diagnosis of DLBCL. In our case, the lymphoma exhibited a strong tendency to be necrotic, making histologic diagnosis difficult. However, selective biopsy from the site of blood flow made the diagnosis possible and proved to be useful.

Cystic splenic lesions: a sonographic approach-retrospective study in 111 patients.

To describe and categorize splenic cystic-appearing lesions (S-CAL) with B-mode and contrast-enhanced ultrasound (CEUS). This retrospective study investigated S-CALs in 111 patients between 2003 and 2023 in an interdisciplinary ultrasound center with B-mode ultrasound, color Doppler sonography (CDS), and CEUS. S-CAL was characterized by echogenicity, diameter, and shape, as well as additional features like septation, calcification, or wall thickening, and CDS/CEUS were used to identify perfusion. Histological examination or imaging follow-up was necessary to determine the nature of S-CAL. Moreover, 'S-CAL with risk' was defined, necessitating further procedures. Four types (0-III) of S-CALs were defined based on ultrasound parameters. Fisher's exact test was used to compare non-parametric data. S-CAL of 111 patients (58 female, 53 men-average age: 58.6 years) was examined. Final diagnoses were: splenic cyst (n = 64, 57.7%); splenic abscess (n = 10, 9.0%); intrasplenic pseudoaneurysm (n = 10, 9.0%); splenic metastasis (n = 10, 9.0%); splenic infarction (n = 6, 5.4%); splenic hematoma (n = 4, 3.6%); other (n = 7, 6.3%). S-CAL groupings were type 0 (n = 11, 9.9%), type I (n = 33, 29.7%), type II (n = 24, 21.6%), and type III (n = 43, 38.7%). 'S-CAL with risk' was diagnosed in n = 41 (36.9%). Malignant S-CAL was only seen in type II (n = 2, 8.2%) and type III (n = 9, 20.9%) (p < 0.001). 'S-CALs with risk' were found more frequently in type 0 (n = 11, 100%), type II (n = 16, 66.7%) and type III (n = 13, 30.2%) than in type I (n = 1, 3%) (p < 0.001). B-mode ultrasound, CDS, and CEUS are useful to further characterize and follow-up S-CAL and identify 'S-CAL with risk', requiring further procedures. Ultrasound imaging is valuable for the detection, categorization, and monitoring of cystic-appearing lesions of the spleen, as well as for the identification of those with risk. An S-CAL may introduce uncertainty in clinical practice as imaging-based risk stratification is missing. B-mode and CEUS, along with the clinical context and follow-up, assist in characterizing and identifying 'S-CAL with risk'. S-CALs encompass various lesions, including simple cysts, metastases, abscesses, and intrasplenic pseudoaneurysms.

Experimental study of contrast-enhanced ultrasound in the evaluation of random-pattern flap blood supply in the early postoperative stage in rats.

This study aims to investigate whether contrast-enhanced ultrasound (CEUS) could be used to reveal the status of blood supply of the superficial flap of rat model in the early postoperative stage. One viable and one ischemic random-pattern flap were prepared on the left and right back of the same rat respectively with a number of 40. CEUS examinations were applied within 12 h and 7 days postoperatively, and the quantitative measurements of microvascular blood volume (BV) of the base and the end of both flaps were expressed using acoustic intensity as a ratio to that of the healthy skin. Within 12 h post operation, there was a smaller BV value of the ischemic ends than that of both the ischemic bases and viable ends (p < 0.001), while no difference was indicated between ischemic bases and viable bases or between viable bases and viable ends. The same result was provided 7 days post operation. Microcirculation of superficial tissues such as random-pattern flaps in this rat model can be assessed quantitatively by CEUS. It could sensitively and accurately reveal the objective status of tissue perfusion in the early postoperative stage.

SP7.6 - Incidence of hepatic pseudoaneurysm formation following blunt and penetrating abdominal trauma in the paediatric cohort: A 6-year retrospective analysis

Abstract Introduction Hepatic pseudoaneurysm (HPA) is a rare but potentially life-threatening sequelae of liver trauma. Little data exists in the literature in regards HPAs in paediatric patients. We aimed to determine the incidence and risk factors of HPA formation in children with blunt and penetrating liver trauma. Methods A retrospective analysis was performed on patients admitted to our institution under the age of 18, found to have liver injury on initial trauma protocoled CT imaging between 2017 &amp; 2022. Patients were identified from The Trauma Audit and Research Network (TARN) database. Data relevant to the study aims was collected. Results 34 patients were identified. (mean age 12 ± 5.4 years 76.5% male 23.5% female) 67.6% of patients suffered blunt injury (mean ISS 34.3 +/- 20.4 95% CI [25.4-43.1] median AAST 3) and 32.4% patients suffered penetrating liver injury (mean ISS 19.5 +/- 9.61 95% CI [12.6-26.4] median AAST 3) Four patients were excluded from further analysis due to loss of life from the primary injury. 18 patients (60%) underwent repeat CT. Of the 12 patients that did not have a repeat scan, 6 patients (50%) had a repeat USS at 6 weeks. follow up CT identified 4 HPAs (11.7%), of which two were treated with embolization. Conclusion HPA formation in paediatric liver trauma presents a significant clinical challenge. While the lack of standardised protocols poses a hurdle, a personalised approach informed by individual patient factors and the use of contrast enhanced ultrasound (CEUS) may optimise HPA detection while minimising radiation exposure.

Safety of contrast-enhanced ultrasound using microbubbles in human pregnancy: A scoping review.

Successful placentation is crucial for fetal development and maintaining a healthy pregnancy. Placental insufficiency can cause a variety of obstetric complications. Despite the many efforts to enhance diagnosing placental insufficiency, no imaging technique has proven satisfactory. A promising imaging technique is contrast-enhanced ultrasound (CEUS) using microbubbles which has proven capable of (micro)vascular imaging. Its use for placental vascularization assessment in human pregnancies remains constrained by limited evidence and safety concerns. This scoping review aims to demonstrate the safety of CEUS used in human pregnancy in the published literature to date. A systematic search using PubMed, Medline, Embase, and Cochrane databases was performed. All studies where contrast-enhanced ultrasound was used in pregnant humans were included. Studies, where there was a planned termination of pregnancy, were excluded. To assess the safety of CEUS during pregnancy, relevant outcomes were divided into the following 3 categories; fetal outcome, maternal outcome, and pregnancy and neonatal outcomes. A total of 13 articles were included, in which 256 women underwent CEUS during pregnancy. No clinically significant maternal or fetal adverse events or negative pregnancy or neonatal outcomes associated with CEUS were described. Based on our findings, we consider expanding the knowledge of this promising diagnostic technique in future larger clinical studies to be safe and relevant.

Enhanced Ultrasound Image Formation with Computationally Efficient Cross-Angular Delay Multiply and Sum Beamforming.

Ultrasound imaging is a valuable clinical tool. It is commonly achieved using the delay and sum beamformer algorithm, which takes the signals received by an array of sensors and generates an image estimating the spatial distribution of the signal sources. This algorithm, while computationally efficient, has limited resolution and suffers from high side lobes. Nonlinear processing has proven to be an effective way to enhance the image quality produced by beamforming in a computationally efficient manner. In this work, we describe a new beamforming algorithm called Cross-Angular Delay Multiply and Sum, which takes advantage of nonlinear compounding to enhance contrast and resolution. This is then implemented with a mathematical reformulation to produce images with tighter point spread functions and enhanced contrast at a low computational cost. We tested this new algorithm over a range of in vitro and in vivo scenarios for both conventional B-Mode and amplitude modulation imaging, and for two types of ultrasound contrast agents, demonstrating its potential for clinical settings.