Jin-Yu Liang

Characterization of small focal liver lesions using real-time contrast-enhanced sonography: diagnostic performance analysis in 200 patients.

Objective. The purpose of this study was to assess the diagnostic performance of real‐time contrast‐enhanced sonography in characterization of small focal liver lesions (FLLs; ≤3.0 cm in diameter). Methods. Two hundred small FLLs in 200 patients were examined by contrast‐enhanced sonography using a contrast‐specific mode of contrast pulse sequencing and a sulfur hexafluoride–filled microbubble contrast agent. The sonographic images were reviewed by 2 independent readers. A 5‐point confidence level was used to discriminate malignant from benign FLLs, and specific diagnoses were recorded. The diagnostic performances were evaluated by receiver operating characteristic (ROC) analysis, and the interobserver agreement was analyzed by weighted κ statistics. Results. After review of contrast‐enhanced sonography, ROC analysis revealed significant improvement in differentiating between malignant and benign small FLLs that the areas under the ROC curve were 0.856 at baseline sonography versus 0.954 at contrast‐enhanced sonography for reader 1 (P < .001) and 0.857 versus 0.954 for reader 2 (P = .003). The sensitivity, negative predictive value, and accuracy for both readers also improved significantly after contrast agent administration (all P < .001). A better result of specific diagnosis was obtained (38.5% [77/200] at baseline sonography versus 80.5% [161/200] at contrast‐enhanced sonography for reader 1 and 34.5% [69/200] versus 80.5% [161/200] for reader 2; both P < .001) after contrast agent administration, and a better interobserver agreement was achieved (κ = 0.425 at baseline sonography versus 0.716 at contrast‐enhanced sonography). Conclusions. Real‐time contrast‐enhanced sonography improves the diagnostic performance in small FLLs compared with baseline sonography.

Imaging of Peripheral Cholangiocarcinoma With Low-Mechanical Index Contrast-Enhanced Sonography and SonoVue Initial Experience

Objective. The purpose of this study was to investigate the imaging findings of peripheral cholangiocarcinoma with low‐mechanical index (MI) contrast‐enhanced sonography. Methods. Eighteen nodules of peripheral cholangiocarcinoma proved by pathologic examination in 18 patients were evaluated with contrast‐enhanced sonography. A low‐MI real‐time contrast‐enhanced sonographic mode (ie, contrast pulse sequencing) and a sulfur hexafluoride‐filled microbubble contrast agent (SonoVue [BR1]; Bracco SpA, Milan, Italy) were used. Results. On contrast‐enhanced sonographic images, all 18 nodules (100%) of peripheral cholangiocarcinoma showed inhomogeneous enhancement during the arterial phase, and the emergence of nodule enhancement was earlier in 3 nodules (16.7%), simultaneous in 13 (72.2%), and later in 2 (11.1%), respectively, when compared with the adjacent liver tissue. During the arterial phase, 8 nodules (44.4%) showed irregular peripheral rimlike hyperenhancement, 2 (11.1%) showed inhomogeneous hyperenhancement, and 8 (44.4%) showed inhomogeneous hypoenhancement. In portal and late phases, all 18 nodules (100%) showed hypoenhancement. When contrast‐enhanced sonography was added for analysis, the confidence levels of the investigators were improved in 15 (83.3%) of 18 nodules, and 17 (94.4%) of 18 peripheral cholangiocarcinomas were correctly characterized. Conclusions. The imaging findings of peripheral cholangiocarcinoma had some characteristics on low‐MI contrast‐enhanced sonography. Knowledge of these characteristics might be beneficial for improving the diagnostic performance of sonography in evaluating this entity.

Real-time contrast-enhanced ultrasound imaging of infected focal liver lesions.

Objective. The purpose of this study was to investigate the features of infected focal liver lesions on contrast‐enhanced ultrasound (CEUS) imaging. Methods. Thirty‐two hepatic abscesses, 15 infected granulomas, and 6 inflammatory pseudotumors in 53 patients were evaluated with real‐time CEUS before awareness of the definitive diagnosis. A 2.4‐mL dose of a sulfur hexafluoride–filled microbubble contrast agent was administered by intravenous bolus injection. Results. The numbers of abscesses with hyperenhancement, isoenhancement, and hypoenhancement in the arterial phase were 26 (81.3%), 5 (15.6%), and 1 (3.1%), respectively. Thirty (93.8%) lesions were irregularly rim enhanced with nonenhanced areas; enhanced septa were shown in 22 (68.8%) lesions; and transient hyperenhancement of liver parenchyma around the lesion was shown in 20 (62.5%). In 31 abscesses with hyperenhancement or isoenhancement in the arterial phase, 25 (80.6%) showed contrast wash‐out and changed in appearance to hypoenhancement in the late phase. As for infected granulomas and inflammatory pseudotumors, 16 (76.2%) lesions showed hyperenhancement or isoenhancement in the arterial phase, and all of them were hypoenhanced in the portal and late phases. Conclusions. Most infected focal liver lesions showed more rapid contrast wash‐out than the surrounding liver parenchyma, which is similar to malignant lesions. Abscesses typically showed features of rim enhancement, enhanced internal septa, nonenhanced central necrotic areas, and transient hyperenhanced liver parenchyma around the lesions. The CEUS appearance of infected granulomas and inflammatory pseudotumors was variable, and a biopsy was necessary for definitive diagnosis.

Diagnostic performance of contrast-enhanced ultrasound for complex cystic focal liver lesions: blinded reader study

The study was aimed at evaluating the diagnostic performance of contrast-enhanced ultrasound (CEUS) in characterizing complex cystic focal liver lesions (FLLs). Sixty-seven complex cystic FLLs in 65 patients were examined with conventional ultrasound (US) and real-time CEUS. The US and CEUS images were reviewed by a resident radiologist and a staff radiologist independently. Receiver operating characteristic (ROC) analysis was performed to evaluate the diagnostic performance, and the interobserver agreement was analysed. The results showed that complete non-enhancement throughout three phases of CEUS or sustained enhancement in the portal and late phases were exhibited in most benign lesions. Conversely, hypo-enhancement in the late phase was seen in all malignancies. After ROC analysis, the areas (Az) under the ROC curve were 0.774 at US versus 0.922 at CEUS (P = 0.047) by the resident radiologist, and 0.917 versus 0.935 (P = 0.38) by the staff radiologist. A significant difference in Az between the resident and the staff radiologists was found for US (0.774 versus 0.917, P = 0.044), whereas not found for CEUS (0.922 versus 0.935, P = 0.42). Interobserver agreement was improved after CEUS (κ = 0.325 at US versus κ = 0.774 at CEUS). Real-time CEUS improves the capability of discrimination between benign and malignant complex cystic FLLs, especially for the resident radiologist.

Unusual benign focal liver lesions: findings on real-time contrast-enhanced sonography.

This presentation aims to provide an overview of the manifestations of some unusual benign focal liver lesions (FLLs) on low–acoustic power contrast‐enhanced sonography (CES) with a sulfur hexafluoride contrast agent.

Shear wave elastography versus real-time elastography on evaluation thyroid nodules: A preliminary study

OBJECTIVE To comparatively evaluate shear wave elastography (SWE) and real-time elastography (RTE) in distinguishing malignant from benign thyroid nodules. METHODS 49 patients with 64 focal thyroid nodules were enrolled and underwent SWE and RTE before surgery. SWE elasticity indices (mean, minimum and maximum value of 2-mm region of interest) of nodules were measured. For RTE, elastograms were assessed by Rago criteria and nodules with scores of 4 or 5 were classified as suspicious for malignancy. Surgery histopathologic results were adopted as diagnostic standard. RESULTS Of the 64 nodules, 19 were papillary thyroid carcinomas and 45 were benign. SWE indices were significantly higher in malignant than benign nodules (P<0.05). Areas under the ROC curves (AUC) of SWE parameters were 0.840, 0.831 and 0.788, which were not significantly different from that of RTE showed as 0.880 (P=0.148-0.482). When the most accurate cut-off, 38.3kPa for mean value was applied to predict malignancy, the diagnostic specificity, sensitivity, accuracy, positive predictive value and negative predictive value of SWE and RTE were 68.4% versus 79.0%, 86.7% versus 84.4%, 81.3% versus 78.1%, 68.4% versus 64.7% and 86.7% versus 83.3%, respectively (P=0.683-1.000). CONCLUSION SWE as a promising tool can be performed in differentiating thyroid nodules with comparable results to RTE.

Contrast-Enhanced Ultrasound for the Characterization of Hepatocellular Carcinoma and Intrahepatic Cholangiocarcinoma.

Purpose and methods: The ability of contrast-enhanced ultrasound (CEUS) to differentiate between hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC) is still controversial. We reviewed the CEUS imaging of 819 patients (HCC=546, ICC=273) with an established pathological diagnosis. The enhancement patterns of lesions and the diagnostic performance of CEUS were analyzed. Results: Arterial hyperenhancement followed by washout was observed in 92.3% (504/546) of the HCC lesions and 85.7% (234/273) of the ICC lesions on CEUS (p<0.05). Additionally, the ICCs presented contrast washout much earlier than the HCCs, with an average time of 27.5 seconds after injecting the contrast agent compared with 70.1 seconds for the HCCs (p<0.05). Peripheral rim-like enhancement was observed in 68.5% (187/273) of the ICCs, which was significantly more common than that in the HCCs (2.0%, 11/546) (p<0.05). When using arterial hyperenhancement with a washout phase later than 43 seconds after injecting the contrast agent and with no peripheral rim-like enhancement as the diagnostic criteria for HCC ≤5 cm in diameter, the area under the curve was 0.808, with 64.1% sensitivity, 97.4% specificity and 73.6% accuracy. Conclusions: Although ICC may show the typical enhancement pattern of HCC on CEUS, peripheral rim-like enhancement and quick contrast washout show high efficiency in the differentiation of HCC from ICC.

Three-dimensional contrast-enhanced ultrasound of the liver: Experience of 92 cases

Three-dimensional contrast-enhanced ultrasound (3D-CEUS) is a combination of three-dimensional ultrasound (3DUS) and contrast-enhanced ultrasound (CEUS). To evaluate the feasibility of 3D-CEUS in liver imaging, investigate possible influencing factors to its image quality, and evaluate the influence of 3D-CEUS to clinical outcome, low acoustic power (mechanical index, 0.08-0.13) 3D-CEUS was carried out in 102 focal liver lesions in 92 patients by using the LOGIQ 9 ultrasound scanner and a volume transducer (frequency range, 2-5 MHz; focusing ability, 2-25 cm in depth; azimuth aperture 5.9 cm). The lesions were classified into two groups: group 1 (n=51) for characterization and group 2 (n=51) for local treatment response evaluation. The factors that influenced the image quality of 3D-CEUS were analyzed. The image quality and usefulness of 3D-CEUS between the two groups were compared by using the chi(2)-test. The results showed that the lesion diameter, location, and scanning route had no significant influence on the image quality in both groups, whereas interfering factors damaged the image quality in group 1. In group 1, during arterial phase, high image quality was more frequently found in hyperenhanced and hypo- or non-enhanced lesions compared with isoenhanced lesions. In group 2, interfering factor and local treatment response had no obvious influence on the image quality. The visualization rate of high image quality was 94.1% (48/51) in group 2 vs. 72.6% (37/51) in group 1 (P=0.012). The investigators found that 3D-CEUS improved confidence but made no change in diagnosis in 19 (37.3%) of 51 lesions in group 1, whereas 41 (80.4%) of 51 lesions in group 2 (P=0.000). 3D-CEUS tends to obtain better image quality and lead to higher diagnostic confidence in the lesions for local treatment response evaluation, and perhaps is more useful in this aspect in future clinical settings.

Value of Contrast-Enhanced Ultrasonography in Assessing the Vascularity of Liver Metastases Comparison With Contrast-Enhanced Computed Tomography

Objective. The purpose of this study was to compare the capability of contrast‐enhanced ultrasonog‐raphy (CEUS) and contrast‐enhanced computed tomography (CECT) in evaluating the vascularity of liver metastases. Methods. Both CEUS and CECT examinations were performed on 70 patients with liver metastases, which were from colon carcinoma in 31, rectal carcinoma in 17, pancreatic carcinoma in 5, and others in 17. In patients with multiple lesions, the most easily observed lesion was selected as the target lesion for evaluation of vascularity. Results. Peak enhancement of the target lesion during the arterial phase was characterized as hyperenhancement, isoenhancement, hypo‐enhancement, and nonenhancement in 61 (87.1%), 6 (8.6%), 3 (4.3%), and 0 (0%) patients on CEUS, respectively, and in 52 (74.3%), 8 (11.4%), 8 (11.4%), and 2 (2.9%) on CECT. Contrast‐enhanced ultrasonography showed more lesions with hyperenhancement than CECT (P < .01). The enhancement pattern during the arterial phase was homogeneous, inhomogeneous, and rimlike in 30 (42.9%), 16 (22.9%), and 24 (34.2%) patients on CEUS and in 13 (18.6%), 8 (11.4%), and 49 (70%) on CECT. Contrast‐enhanced ultrasonography revealed more lesions with homogeneous enhancement than CECT (P < .01). Contrast‐enhanced ultrasonography showed dysmorphic vessels in 33 patients (47.1%) during the arterial phase, whereas CECT showed dysmorphic vessels in 27 (38.6%; P < .01). Contrast‐enhanced ultrasonography showed hypervascular lesions in 58.6% of patients, whereas CECT showed hypervascular lesions in 12.9% (P < .01). Conclusions. Contrast‐enhanced ultrasonography was superior to CECT in assessing the vascularity of liver metastases.

Does the echogenicity of focal liver lesions on baseline gray-scale ultrasound interfere with the diagnostic performance of contrast-enhanced ultrasound?

The objective was to evaluate whether the echogenicity of focal liver lesions (FLLs) on baseline gray-scale ultrasound (US) interferes with the diagnostic performance of contrast-enhanced US (CEUS) for small FLLs. Three-hundred and eighty-eight patients were examined by real-time CEUS using a sulfur hexafluoride-filled microbubble contrast agent. The images of 114 hyperechoic lesions, 30 isoechoic lesions and 244 hypoechoic lesions were reviewed by two blinded independent readers. A five-point confidence level was used to discriminate malignant from benign lesions, and specific diagnoses were made. The diagnostic performances were evaluated by receiver-operating characteristic (ROC) analysis. The diagnostic performances of CEUS on hyperechoic lesions in terms of the areas (Az) under the ROC curve were 0.987 (reader 1) and 0.981 (reader 2), and were 0.987 (reader 1) and 0.984 (reader 2) for iso- and hypoechoic lesions, respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 87.0–95.9%, 93.1–100%, 88.6–100%, 70.0–97.1% and 90.0–95.1%, respectively. The echogenicity of FLLs on baseline gray-scale US does not appear to interfere with the diagnostic ability of CEUS for small FLLs.