Ultrasound Quarterly最新文献

Abstract: Contrast-enhanced ultrasound (CEUS) continues to be an ever-growing tool in radiation-free imaging. While it has been widely used in cardiac imaging, CEUS has only recently become an Food and Drug Administration-approved and viable modality for evaluation of abdominal structures. Ultrasound contrast agents are nontoxic, microbubble-based vascular agents and can be used to reliably assess enhancement patterns of various lesions in real time. In particular, it's non nephrotoxic nature makes CEUS a particularly important tool in renal failure patients requiring serial follow-up. This review provides a comprehensive discussion on the utility of CEUS agents, imaging techniques, comparison with traditional cross-sectional imaging modalities, and its application in diagnosing kidney and liver lesions. This pictorial review is illustrated with cases of renal and hepatic lesions that the practicing radiologist should become familiar with as CEUS becomes increasingly popular.

Abstract: Gallbladder polyps (GPs) are a common incidental finding on ultrasound; however, important differences in recommended management exist among professional society guidelines.An electronic survey was sent to 189 fellows of the Society of Radiologists in Ultrasound. Main outcomes included preferences and current practice patterns for evaluation, management, and surveillance of GPs as well as personal lifetime experience with gallbladder sonography and GPs.A total of 64 subjects (34%) with experience in gallbladder sonography completed the study. The estimated combined total number of gallbladder scans seen by the responders was 3,071,880. None of fellows had ever seen a pedunculated GP <1 cm detected on ultrasound that was proven to be malignant at the time of detection or during subsequent follow-up. All of the fellows used size as a feature to stratify recommendations. The median size threshold currently used by Society of Radiologists in Ultrasound fellows for recommending ultrasound follow-up was 6 mm, and their preferred threshold was 7 mm. The median size threshold for recommending surgical consultation was 10 mm, and the preferred threshold was 10 mm. Wall thickening and shape were considered important factors by 76% and 67% of respondents, respectively.Society of Radiologists in Ultrasound fellows tend to provide recommendations most similar to the American College of Radiology and Canadian Association of Radiology guidelines for management of GPs. Many would prefer guidelines that result in fewer recommendations for follow-up and surgical consultation. Despite a substantial combined experience, this survey did not uncover any case of a small GP that was malignant.

Abstract: The development of high-frequency ultrasound made the diagnosis of pancreaticobiliary maljunction (PBM) possible. However, no study has been performed to clarify the sensitivity and specificity of transabdominal ultrasound (TAUS) in the diagnosis of PBM. The purpose of this study was to evaluate the accuracy of TAUS in the diagnosis of pediatric PBM and to assess factors that may influence the accuracy of ultrasound. This was a prospective study and 43 patients with suspected PBM were enrolled. All of these patients underwent TAUS examination to detect the pancreaticobiliary ductal union. Final diagnoses were determined by endoscopic retrograde cholangiopancreatography or intraoperative cholangiography. Sensitivity and specificity were calculated. Fisher exact test was used to analyze the difference of sonographic features between false-negative group and true-positive group. Transabdominal ultrasound demonstrated 77.4% (95% confidence interval, 58.5%-89.7%) sensitivity and 100% (95% confidence interval, 69.9%-100%) specificity for PMB diagnosis. In the false-negative group, infant patients (71.4% vs 16.7%, P = 0.012), cystic dilatation of the common bile duct (CBD) (71.4% vs 16.7%, P = 0.012), and stenosis of the distal CBD (71.4% vs 16.7%, P = 0.012) were more frequently observed than in the true-positive group. On the other hand, the true-positive group showed a higher incidence of protein plugs than the false-negative group (62.5% vs 0%, P = 0.007). Transabdominal ultrasound may serve as a potential alternative detection modality for pediatric patients with suspected PBM. Nondetection of the anomaly may be attributed to factors, such as younger age, cystic dilatation of the CBD, and stenosis of the distal CBD.

Abstract: Hemangioma is the most common benign liver tumor and is frequently encountered as an incidental finding on imaging. The classic enhancement pattern of hemangioma is diagnostic on contrast-enhanced ultrasound (CEUS), and it follows the same pattern of enhancement on computed tomography and magnetic resonance imaging. However, there is a subset of hemangiomas that demonstrate atypical enhancement patterns on CEUS. The ability to recognize the different enhancement patterns and discern when additional imaging or biopsy may be necessary is essential to accurately interpret an atypical hemangioma on CEUS. This article reviews various enhancement patterns of hemangioma on CEUS to avoid pitfalls in characterization of focal liver lesions on CEUS.

Abstract: In this study, we aimed to evaluate the liver stiffness (LS) values and the right ventricle (RV) functions after atrial septal defect (ASD) closure treatment. Sixty-six patients were included (38 female, 28 male) in the study. Patients were grouped into 3 subgroups (group I = 21 patients without ASD closure, group II = 38 patients who underwent ASD closure, and group III = 11 patients with ASD and Eisenmenger syndrome). After 1-year follow-up of the patients who underwent ASD closure, LS was assessed using the liver elastography technique. Echocardiographic changes and LS changes over time were compared. Absolute Δ-LS and Δ-liver size were found to be significantly decreased in group II compared with the other groups. While liver size, LS levels, RV and left ventricle (LV) dimensions, and tricuspid regurgitation pressure gradient were found to be significantly decreased; the tricuspid annular plane systolic excursion and the LV ejection fraction were significantly increased in group II. In addition, Δ-LV and Δ-RV dimensions and Δ-tricuspid regurgitation pressure gradient values were statistically significant and Δ-tricuspid annular plane systolic excursion and LV ejection fraction values were statistically higher in group II compared with the other groups. In conclusion, our study demonstrates that the LS is another parameter, which significantly decreases in patients treated with ASD occluder devices and can be used as an objective follow-up parameter in addition to classic echocardiographic measurements.

Abstract: The etiology of distal common bile duct (CBD) dilatation is complex. Linear-array endoscopic ultrasonography (EUS) can not only visualize the distal and surrounding structures of the bile duct closely but also obtain pathological specimens by fine-needle aspiration, which provides an important basis for the diagnosis and differential diagnosis. The purpose of this study was to evaluate the diagnostic value of linear-array EUS in the etiology of distal CBD dilatation. Patients with distal CBD dilatation underwent linear-array EUS in the endoscopic center of The Second Affiliated Hospital of Soochow University and Traditional Chinese Medicine Hospital of Kunshan were collected from January 2015 to June 2019. The pathology results after surgery, endoscopic pathology, computed tomography (CT), and magnetic resonance imaging (MRI) results were retrospectively analyzed. The diagnostic accuracy of linear-array EUS and CT or MRI was compared. For the diagnosis of choledocholithiasis, the diagnostic accuracy of linear-array EUS was 97.5%, which was significantly higher than that of MRI (86.36%) and CT (89.74) (P < 0.001 and 0.006, respectively). The diagnostic accuracy of linear-array EUS for periampullary tumors was 93.75%, which was higher than MRI and CT with an accuracy of 82.73% and 80.34% (P = 0.004 and 0.001, respectively). Linear EUS was effective for the etiological diagnosis of distal CBD dilatation.

Abstract: Ultrasound-based spleen elastography is a promising surrogate to predict portal hypertension noninvasively. In contrast to defined standards for liver stiffness measurement, the standardized examination procedures for 2-dimensional (2D) shear wave elastography spleen elastography have not been established yet. The aim was to investigate the impact of location of stiffness measurement on 2D shear wave elastography spleen stiffness measurement (SSM). Patients with splenomegaly were enrolled. Both B-mode ultrasound and elastography of spleen were performed. For SSM, 3 regions were chosen for spleen measurement: lower pole region, central region, and the region between lower pole and center. Mean SSM value, success rate, and reliability predicators (standard deviation, standard deviation/mean, size of region of interest) were assessed. A total of 124 patients were included. For mean SSM value, there were no significant differences among 3 regions. Spleen stiffness measurement success rate in lower pole region, central region, and the region between them was 63.7% (79), 91.1% (113), and 78.2% (97), respectively. The success rate in the central region was significantly higher than that in the other 2 regions (P < 0.05). Reliability in the central region was also highest among the 3 regions. Location of stiffness measurement has a limited effect on SSM. Changing location of measurement will not influence mean stiffness value in spleen.

Abstract: Shear wave elastography (SWE) is a new type of ultrasonic elastography that can quantitatively assess the elasticity and stiffness of tissues. This study aimed to investigate the value of SWE in evaluating the effectiveness of microwave ablation in hepatic malignancies. A total of 24 patients (including 30 lesions) with liver malignancies receiving microwave ablation treatment at the Cancer Hospital of Guangzhou Medical University from April 2018 to January 2019 were enrolled. The elastography was performed within 1 week before and after ablation. The SWE values in the central zone, the marginal zone of the lesion, and peripheral liver parenchyma were collected and analyzed. Before ablation, the mean of SWE value was 65.80 ± 13.37 kPa for the central zone of the tumor and 39.93 ± 7.87 kPa for the marginal zone, both of which were significantly greater than that for the perinatal liver parenchyma (12.85 ± 2.67 kPa, both P < 0.05). In the central and marginal zone of the lesions, the SWE value was significantly elevated after ablation (both P < 0.001) but not in the peripheral liver parenchyma (P = 0.444). Receiver operating characteristic curve analysis showed that the cutoff value for ablation in the marginal zone was 53.87 kPa, suggesting that an SWE exceeding 53.87 kPa is an index guaranteeing the ablation effectiveness. These results suggested that SWE has the potential to be used in evaluating the effectiveness of microwave ablation in liver cancers.

Abstract: We aimed to investigate the clinical feasibility of shear wave dispersion slope for assessing nonalcoholic steatohepatitis (NASH) in patients with morbid obesity before bariatric surgery.This prospective study collected data from 25 participants who received liver biopsy during bariatric surgery between February 2019 and December 2020. All participants underwent ultrasonography shear wave elastography before surgery and shear wave speed and shear wave dispersion slope were measured. Liver specimens were evaluated by 1 pathologist scored histologically for nonalcoholic fatty liver disease (NAFLD). Ultrasonography measurements were compared according to histopathologic findings. Diagnostic performance in differentiating NASH from NAFLD was evaluated using the area under the receiver operating characteristic curve (AUC). Median shear wave speed (1.48 vs 1.62 m/s, P = 0.014) and dispersion slope (8.40 vs 11.80 [m/s]/kHz, P = 0.004) were higher in NASH group than in NAFLD group. Shear wave dispersion slope tended to increase step by step as the severity of activity grade (P = 0.032) and hepatic fibrosis (P = 0.015) increased. The AUC of shear wave dispersion slope for differentiating NASH from NAFLD (AUC, 0.83; 95% confidence intervals, 0.66-1.00) was higher than that of shear wave speed (AUC, 0.78; 95% CI, 0.60-0.97), although it did not reach statistical significance (P = 0.729). Shear wave dispersion slope could be a feasible tool for assessing NASH in patients with morbid obesity.