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.

Impact factors and the optimal parameter of acoustic structure quantification in the assessment of liver fibrosis

The aims of the present study are to assess the impact factors on acoustic structure quantification (ASQ) ultrasound and find the optimal parameter for the assessment of liver fibrosis. Twenty healthy volunteers underwent ASQ examinations to evaluate impact factors in ASQ image acquisition and analysis. An additional 113 patients with liver diseases underwent standardized ASQ examinations, and the results were compared with histologic staging of liver fibrosis. We found that the right liver displayed lower values of ASQ parameters than the left (p = 0.000-0.021). Receive gain experienced no significant impact except gain 70 (p = 0.193-1.000). With regard to different diameter of involved vessels in regions of interest, the group ≤2.0 mm differed significantly with the group 2.1-5.0 mm (p = 0.000-0.033) and the group >5.0 mm (p = 0.000-0.062). However, the region of interest size (p = 0.438-1.000) and depth (p = 0.072-0.764) had no statistical impact. Good intra- and inter-operator reproducibilities were found in both image acquisitions and offline image analyses. In the liver fibrosis study, the focal disturbance ratio had the highest correlation with histologic fibrosis stage (r = 0.67, p < 0.001). In conclusion, the testing position, receive gain and involved vessels were the main factors in ASQ examinations and focal disturbance ratio was the optimal parameter in the assessment of liver fibrosis.

Diagnosis of Testicular Adrenal Rest Tumors on Ultrasound: A Retrospective Study of 15 Cases Report

The aim of this study was to evaluate the imaging features of testicular adrenal rest tumors (TARTs) on baseline ultrasound (BUS).The imaging features of 30 TART lesions pathologically or clinically confirmed in 15 patients who had undergone BUS were evaluated, and the sonographic characteristics of the lesions were analyzed.All 15 cases were bilateral and located near the testicular mediastinum. Approximately 56.7% (17/30) of the TART lesions exhibited homogeneous hypoechogenicity, 36.7% (11/30) of the lesions exhibited heterogeneous hypoechogenicity, and 6.6% (2/30) of the lesions exhibited heterogeneous isoechogenicity. In addition, 76.7% (23/30) of the lesions exhibited a rich blood supply, whereas 23.3% (7/30) of the lesions exhibited a scarce blood supply.The sonographic characteristics of the TARTs were bilateral growth, location adjacent to the testicular mediastinum, hypoechogenicity, and rich blood supply, which may play important roles in early clinical diagnosis.

Who Is Doing the Dance in Epididymis: The Principle of Moblile Echogenicities Without Filarial Infection: Case Report

The aim of this study was to explore the principle of moblile echogenicities in epididymis in patients with a history of postvasectomy or infertility, which were reported as the characteristic sonographic sign of filarial infection.We reported a 38-year-old man presented with a 3-year history of infertility after marriage. Ultrasound imaging revealed an enlarged body in the inner left epididymis along with innumerable punctate mobile echogenicities, which showed random to-and-fro movements in the left epididymis. This had previously been recognized as the sonographic filarial dance sign of live filarial worms or microfilaria. The patient subsequently underwent needle aspiration of the left epididymis.Histopathological examination confirmed that the mobile echogenicities were a large number of macrophages with phagocytized sperm or clumps of agglutinated sperm. Our report includes a video clip that will help familiarize readers with this phenomenon.Our case highlighted that moblile echogenicities should be an important sign for epididymal obstruction to initiate corresponding treatment.

Role of portal vein tumor thrombosis in quantitative perfusion analysis of contrast-enhanced ultrasound of hepatocellular carcinoma

The goal of our study was to evaluate the differences between quantitative parameters of hepatocellular carcinoma (HCC) with or without portal vein tumor thrombosis (PVTT) on contrast-enhanced ultrasound (CEUS). Twenty-four patients with HCC with PVTT and 48 without PVTT underwent CEUS using sulfur hexafluoride microbubbles. Dynamic images were analyzed with quantification software. Time-intensity curves were obtained for HCC and surrounding liver parenchyma, and parameters including the intensity maximum (IMAX), rising time (RT), mean transit time and time to peak (TTP) were compared within and between the PVTT and control groups, respectively. RT and TTP of HCC were significantly faster than those of surrounding liver parenchyma in both the PVTT and control groups. IMAX of HCC was significantly stronger than that of surrounding liver in the control group, but not significantly different from that of liver parenchyma in the PVTT group. RT and TTP of HCC and surrounding liver were significantly faster in the PVTT group compared with the control group, whereas IMAX values of HCC in the PVTT group were lower than those in the control group. HCC with PVTT presents different hemodynamic parameters, with faster RT and TTP and lower IMAX than those for HCC without PVTT. Quantitative perfusion analysis of CEUS may be a potential method for predicting PVTT.

Differentiation of Atypical Hepatocellular Carcinoma from Focal Nodular Hyperplasia: Diagnostic Performance of Contrast-enhanced US and Microflow Imaging

PURPOSE

To evaluate diagnostic performance of contrast-enhanced (CE) ultrasonography (US) and microflow (MF) imaging in differentiation of atypical hepatocellular carcinoma (HCC) from focal nodular hyperplasia (FNH).

MATERIALS AND METHODS

Institutional review board approval was obtained, and informed consent was waived. A total of 103 patients (mean age, 43.9 years; age range, 17-75 years) were included; 38 patients with HCC and 65 with FNH underwent CE US, and vascular architecture pattern (VAP) and arrival time parametric (ATP) images were analyzed. Resident and staff radiologists independently and retrospectively reviewed CE US, VAP, and ATP images. χ(2) test and logistic regression analysis were applied to identify specific features of FNH or HCC on CE US and MF images. To compare diagnostic performance of CE US with or without MF imaging, four sets of criteria were assigned: (a) routine CE US alone, (b) VAP and CE US, (c) ATP imaging and CE US, and (d) all three methods in combination. Sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve (AUC) of resident and staff radiologists were analyzed. Cohen κ statistic was used to assess agreement of CE US and MF imaging features between staff and resident radiologists.

RESULTS

MF imaging offered significant improvements over most detection rates achieved with routine CE US signs in both groups. For staff radiologists, AUCs from criteria sets 3 (AUC = 0.873, P < .05) and 4 (AUC = 0.887, P < .05) were significantly higher than AUC from criteria set 1 (AUC = 0.835). For resident radiologists, specificity (71% and 69% vs 25%, P < .01) and accuracy (78% and 79% vs 50%, P < .01) of criteria sets 3 and 4 were significantly higher than those of criteria set 1. Moreover, AUCs for criteria sets 2 (AUC = 0.728, P < .05), 3 (AUC = 0.823, P < .01), and 4 (AUC = 0.857, P < .01) were significantly higher than those for criteria set 1 (AUC = 0.667).

CONCLUSION

When compared with routine CE US, MF imaging can more effectively depict specific features and offers improved diagnostic performance in the differentiation of atypical HCC from FNH, especially when used by resident radiologists. Online supplemental material is available for this article.

Differential diagnosis of gallbladder wall thickening: the usefulness of contrast-enhanced ultrasound

he purpose of this study was to evaluate the usefulness of contrast-enhanced ultrasound (CEUS) in the differential diagnosis of gallbladder wall (GBW) thickening and determine the predictors of malignant GBW thickening. One hundred fifty-nine patients with GBW thickening, including 76 men and 83 women, from eight institutions were enrolled. CEUS was performed after injection of a sulfur hexafluoride microbubble-based ultrasound contrast agent. Multiple logistic regression analysis was used to reveal independent predictor sassociated with malignant GBW thickening. The final diagnoses were 48 gallbladder carcinomas and 111 benign gallbladder diseases.Maximal thicknesses of the GBW in malignant and benign GB Wthickening were 17.3 ± 5.2 (6 – 30) mm and 8.6 ± 5.1 (4 – 26) mm respectively (p , 0.001). CEUS revealed significant differences in intralesional vessels, enhancement homogeneity, time to hypo-enhancement, inner layer discontinuity, outer layer discontinuity and adjacent liver involvement (all p-values , 0.05) between malignant and benign GBW thickening. Patient age . 46.5 y, focal GBW thickening, inner layer discontinuity and outer layer discontinuity were found to be associated with malignancy by multiple logistic regression analysis (all p-values , 0.05). Receiver operating characteristic curve analysis revealed Az values for patient age, focal GBW thickening, inner wall discontinuity and outer wall discontinuity of 0.709 (95%confidence interval [CI]: 0.627–0.790), 0.714 (95% CI: 0.630–0.798), 0.860 (95%CI: 0.791 – 0.928) and 0.858 (95% CI: 0.783 – 0.933), respectively. CEUS is useful in the differential diagnosis between malignant and benign GBW thickening. Focal GBW thickening, inner wall discontinuity and outer wall discontinuity observed on CEUS are diagnostic clues for malignant GBW thickening.

Contrast-enhanced ultrasound versus conventional ultrasound in the diagnosis of polypoid lesion of gallbladder: a multi-center study of dynamic microvascularization

OBJECTIVE

To assess the value of contrast-enhanced ultrasound (CEUS) in the diagnosis of polypoid lesions of gallbladder (PLGs).

METHODS

CEUS was performed to 116 patients (mean age, 49.6 years; range, 21-80 years) with PLGs from 8 university hospitals. 9 cases of biliary sludge were proven by surgery and the remaining 107 cases were confirmed by histopathological examination. The confidence level, diagnostic performance, inter-observer agreement of two independent readers with different experience was assessed. The readers were blind to the imaging and clinical results of the patients.

RESULTS

There were significant differences between benign and malignant PLGs in patient age, gender, lesion size, echogenicity, stalk, time-to-peak, vascularity on CEUS, enhancement pattern, and wall destruction. The confidence levels increased significantly and the interobserver agreement increased from 0.425 to 0.601 after CEUS. The sensitivity increased from 22.2 to 77.8% after CEUS in the staff radiologist, and from 22.2 to 66.7% in the resident radiologist. The correctly characterized lesions were 64.7% before versus 87.1% after CEUS (P=0.125) for the staff radiologist, and 57.8% versus 70.7% for the resident radiologist (P=0.007). No significance was found in the subgroup of lesions≤1.0 cm before and after CEUS for the two radiologists.

CONCLUSIONS

CEUS using convex multifrequency probes could detect the dynamic microvascularization of PLGs greater than 1.0 cm and facilitate the differentiation between benign and malignant tumors.

Percutaneous radiofrequency ablation of malignant liver tumors with ultrasound and CT fusion imaging guidance

BACKGROUND

To evaluate the feasibility, accuracy, and utility of sonography (US) and CT fusion imaging guidance for radiofrequency ablation (RFA) of malignant liver tumors not visualized on conventional US.

METHODS

Seventy-seven patients with hepatocellular carcinoma and 15 patients with metastatic liver cancer with a total of 136 lesions underwent RFA with US and CT fusion imaging guidance. The mean number of punctures, success rate of a single ablation session, local tumor progression rates, and long-term outcome were evaluated. Treatment efficacy was evaluated by dynamic CT and contrast-enhanced US 1 month after RFA.

RESULTS

RFA was technically feasible in all patients, and no major complications occurred. The mean ± SD time needed to synchronize US and CT images was 13.9 ± 11.9 minutes (range, 5-55 minutes). The success rate of a single ablation session was 83.8% (114/136), and tumor residue was present in 7.4% of lesions (10/136). The mean number of treatment sessions was 1.2 ± 0.5 sessions. During follow-up, local tumor progression was observed for 15 (11.9%) lesions. Distant tumor recurrence was found in 51 (55.4%) patients.

CONCLUSIONS

US and CT fusion-assisted RFA is a safe and efficacious treatment for patients with hepatocellular carcinoma and metastatic liver cancer.

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.

Real-time contrast enhanced ultrasound imaging of focal splenic lesions

OBJECTIVE

To investigate the imaging features of focal splenic lesions (FSLs) on contrast-enhanced ultrasound (CEUS).

METHODS

Thirty two patients with FSLs proved by pathology were retrospectively analyzed. CEUS was performed using intravenous bolus injection of 2.4 ml sulfur hexafluoride-filled microbubble contrast agent and real time scanning. There were hemangioma (n=7), lymphoma (n=8), true cyst (n=3), infarction (n=4), hematolymphangioma (n=2), metastasis tumor (n=2), and one for each of the following entities extramedullary hemopoiesis, hamartoma, tuberculosis, Langerhans' cell histiocytosis, inflammatory pseudotumor and myxofibrosarcoma.

RESULTS

Among 21 benign lesions, 4 infarctions and 3 cysts presented non-enhancement throughout CEUS scanning, and the other 14 lesions displayed various enhancement levels with 6 (42.9%) hyper-enhancement, 2 (14.3%) iso-enhancement and 6 (42.9%) hypo-enhancement in arterial phase and 11 (78.6%) hypo-enhancement, 1 (7.1%) iso-enhancement and 2 (14.3%) hyper-enhancement in late phase, respectively. The enhancement pattern included 9 (64.3%) homogeneous, 4 (28.6%) heterogeneous and 1 (7.1%) rim-like enhancement. As for the malignant FSLs, all the lesions became completely or extensively hypo-enhancement during the late phase no matter their vascularity during arterial phase.

CONCLUSIONS

The CEUS features reported in this series may enrich the knowledge for CEUS characterization of FSLs.

Gram-scale synthesis of catalytic Co9S8 nanocrystal ink as a cathode material for spray-deposited, large-area dye-sensitized solar cells

We report the development of Co9S8 nanocrystals as a cost-effective cathode material that can be readily combined with spraying techniques to fabricate large-area dye-sensitized solar cell (DSSC) devices and can be further connected with series or parallel cell architectures to obtain a relatively high output voltage or current. A gram-scale synthesis of Co9S8 nanocrystal is carried out via a noninjection reaction by mixing anhydrous CoCl2 with trioctylphosphine (TOP), dodecanethiol and oleylamine (OLA) at 250 °C. The Co9S8 nanocrystals possess excellent catalytic ability with respect to I(-)/I3(-) redox reactions. The Co9S8 nanocrystals are prepared as nanoinks to fabricate uniform, crack-free Co9S8 thin films on different substrates by using a spray deposition technique. These Co9S8 films are used as counter electrodes assembled with dye-adsorbed TiO2 photoanodes to fabricate DSSC devices having a working area of 2 cm(2) and an average power conversion efficiency (PCE) of 7.02 ± 0.18% under AM 1.5 solar illumination, which is comparable with the PCE of 7.2 ± 0.12% obtained using a Pt cathode. Furthermore, six 2 cm(2)-sized DSSC devices connected in series output an open-circuit voltage of 4.2 V that can power a wide range of electronic devices such as LED arrays and can charge commercial lithium ion batteries.

Practice guidelines for ultrasound-guided percutaneous microwave ablation for hepatic malignancy

Primary liver cancer and liver metastases are among the most frequent malignancies worldwide, with an increasing number of new cases and deaths every year. Traditional surgery is only suitable for a limited proportion of patients and imaging-guided percutaneous thermal ablation has achieved optimistic results for management of hepatic malignancy. This synopsis outlines the first clinical practice guidelines for ultrasound-guided percutaneous microwave ablation therapy for hepatic malignancy, which was created by a joint task force of the Society of Chinese Interventional Ultrasound. The guidelines aim at standardizing the microwave ablation procedure and therapeutic efficacy assessment, as well as proposing the criteria for the treatment candidates.

Radiofrequency ablation before intratumoral injection of (131)I-chTNT improves the tumor-to-normal tissue ratio in solid VX2 tumor

PURPOSE

This study was aimed to investigate whether the tumor necrosis induced by radiofrequency ablation (RFA) can improve the ratio of tumor-to-normal tissue (T/NT) after intratumoral injection of (131)I-chTNT.

MATERIALS AND METHOD

Eighteen New Zealand rabbits bearing VX2 tumor on the thigh were randomly divided into two treatment groups (control group: intratumoral injection of (131)I-chTNT alone; RFA group: RFA + intratumoral injection of (131)I-chTNT 3 days after RFA) and each group was further divided into three subgroups I, II, and III (1-2 cm, 2-3 cm, and 3-4 cm in maximum diameter, respectively), by the tumor size. SPECT was performed to evaluate the T/NT on days 1, 8, and 15 after (131)I-chTNT injection.

RESULTS

After treatment, all rabbits underwent the SPECT whole-body scan and the T/NT was analyzed. The results showed that T/NT in the RFA group (55.45±41.83) was significantly higher compared with the control group (7.23±5.61) (F=18.89, p=0.001). Meanwhile, a linear ascending trend was found for T/NT in the RFA group along with the follow-up time (r=0.47, p=0.01). The tumor size or the dose of (131)I-TNT injection had no significant effect on the variation of T/NT in both groups (p>0.05).

CONCLUSION

RFA before intratumoral injection of (131)I-chTNT can dramatically improve T/NT, demonstrating the potential application of this combination therapy.

Evaluation of the vascular architecture of focal liver lesions using micro flow imaging

OBJECTIVES

To identify the vascular architecture of focal liver lesions using micro flow imaging and compare it with characteristics on contrast harmonic imaging during the arterial phase.

METHODS

Micro flow imaging and contrast harmonic imaging were performed in 118 patients with various focal liver lesions: hepatocellular carcinoma (n = 70), metastasis(n = 19), intrahepatic cholangiocarcinoma (n = 3), lymphoma (n = 1), hemangioma (n = 17), and focal nodular hyperplasia (n = 8). The vascular architecture of the lesions on micro flow imaging was evaluated by 2 investigators independently to reveal 6 patterns (types IVI). Enhancement characteristics on contrast harmonic imaging were also evaluated.

RESULTS

Inter-reader agreement for delineating the vascular architecture was higher on contrast harmonic imaging (κ= 0.856) than micro flow imaging (κ= 0.613). On micro flow imaging, the vascular patterns of hepatocellular carcinomas were types I (28.6%), II (65.7%), and III (5.7%). On contrast harmonic imaging, 44 of 70 (62.9%) hepatocellular carcinomas showed chaotic vessels, of which 40 were type II and 4 were type II. The vascular patterns of metastases were types IV (78.9%), I (10.5%), and II (10.5%). Typical rim enhancement was identified in 57.9% of metastases on contrast harmonic imaging, and all were type IV. The vascular patterns of focal nodular hyperplasia were types VI (87.5%) and I (12.5%). Typical spoked wheel arteries were identified on contrast harmonic imaging in 2 focal nodular hyperplasia cases. The vascular patterns of hemangiomas were types V (94.1%) and II (5.9%). Typical peripheral nodular enhancement was identified in 88.2% of hemangiomas on contrast harmonic imaging, and all were type V. The χ(2) test revealed that differences in vascular architecture between the lesions were significant on micro flow imaging (P < .001).

CONCLUSIONS

Micro flow imaging permitted detailed delineation of the vascular architecture of focal liver lesions. Hepatocellular carcinoma, metastasis, focal nodular hyperplasia, and hemangioma showed characteristic vascular architecture.

Revealing impaired blood supply to the bile ducts on contrast-enhanced ultrasound: a novel diagnosis method to ischemic-type biliary lesions after orthotropic liver transplantation

Ischemic-type biliary lesions (ITBLs) are a major source of morbidity and mortality after orthotropic liver transplantation (OLT). The study determines diagnostic accuracy of contrast-enhanced ultrasound (CEUS) in diagnosing ITBLs. Nine healthy volunteers, six OLT recipients without complications, 36 OLT patients with complications (12 without ITBLs and 24 with ITBLs) underwent CEUS. Two radiologists reviewed the sonograms of the hilar bile duct wall and established specific criteria used to detect ITBLs. Next, the sonograms of six OLT recipients without complications and 36 patients with complications (12 without ITBLs and 24 with ITBLs) were retrospectively reviewed by two other independent, blinded radiologists. The sensitivity, specificity and accuracy of CEUS were evaluated. The main feature differentiating ITBLs from three other groups was non- or hypo-enhancement of the hilar bile duct wall in arterial phase (all p < 0.05), which was selected as the primary criterion for subsequent study. The sensitivity, specificity and accuracy were 66.7%, 88.9% and 76.2% for reader 1 and 62.5%, 88.9% and 73.8% for reader 2, respectively. A good interobserver agreement (κ = 0.85) was achieved. In this study, CEUS shows promise of detection of ITBLs by revealing impaired blood supply to the bile ducts, but more studies will be needed to establish its usefulness.

Contrast-enhanced ultrasound features of histologically proven focal nodular hyperplasia: diagnostic performance compared with contrast-enhanced CT

OBJECTIVES

To investigate and compare contrast-enhanced ultrasound (CEUS) in the characterisation of histologically proven focal nodular hyperplasia (FNH) with contrast-enhanced computed tomography (CECT).

METHODS

CEUS was performed in 85 patients with 85 histologically proven FNHs. Enhancement, centrifugal filling, spoke-wheel arteries, feeding artery and central scarring were reviewed and correlated with lesion size or liver background. Independent factors for predicting FNH from other focal liver lesions (FLLs) were evaluated. Forty-seven FLLs with CECT were randomly selected for comparison of diagnostic performance with CEUS.

RESULTS

Centrifugal filling was more common (P = 0.002) and the significant predictor (P = 0.003) in FNHs ≤3 cm. Lesion size or liver background has no significant influence on the detection rate of the spoke-wheel arteries and feeding artery (P > 0.05). Central scarring was found in 42.6 % of FNHs ≥3 cm (P = 0.000). The area under the ROC curve, sensitivity and specificity showed no significant differences between CEUS and CECT (P > 0.05), except that the sensitivity of CEUS was better for reader 1 (P = 0.041).

CONCLUSION

CEUS is valuable in characterising centrifugal filling signs or spoke wheels in small FNHs and should be employed as the first-line imaging technique for diagnosis of FNH.

KEY POINTS

• The confident diagnosis of focal nodular hyperplasia is important in liver imaging. • The centrifugal filling sign is useful for diagnosis of FNHs ≤3 cm. • Contrast-enhanced ultrasound and contrast-enhanced CT have similar diagnostic performance for FNH. • CEUS should be the first-line imaging technique for the diagnosis of FNH.

Role of contrast-enhanced ultrasound in follow-up assessment after ablation for hepatocellular carcinoma

AIM: To assess the usefulness of contrast-enhanced ultrasound (CEUS) during follow-up after percutaneous ablation therapy for hepatocellular carcinoma (HCC).

METHODS: A total of 141 patients with HCCs who received percutaneous ablation therapy were assessed by paired follow-up CEUS and contrast-enhanced computed tomography (CECT). The follow-up scheme was designed prospectively and the intervals between CEUS and CECT examinations were less than 14 d. Both images of follow-up CEUS and CECT were reviewed by radiologists. The ablated lesions were evaluated and classified as local tumor progression (LTP) and LTP-free. LTP was defined as regrowth of tumor inside or adjacent to the successfully treated nodule. The detected new intrahepatic recurrences were also evaluated and defined as presence of intrahepatic new foci. On CEUS and CECT, LTP and new intrahepatic recurrence both were displayed as typical enhancement pattern of HCC (i.e., hyper-enhancing during the arterial phase and washout in the late phase). With CECT as the reference standard, the ability of CEUS in detecting LTP or new intrahepatic recurrence during follow-up was evaluated.

RESULTS: During a follow-up period of 1-31 mo (median, 4 mo), 169 paired CEUS and CECT examinations were carried out for the 141 patients. For a total of 221 ablated lesions, 266 comparisons between CEUS and CECT findings were performed. Thirty-three LTPs were detected on CEUS whereas 40 LTPs were detected on CECT, there was significant difference (P < 0.001). In comparison with CECT, the numbers of false positive and false negative LTPs detected on CEUS were 6 and 13, respectively; the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and overall accuracy of CEUS in detecting LTPs were 67.5%, 97.4%, 81.8%, 94.4% and 92.3%, respectively. Meanwhile, 131 new intrahepatic recurrent foci were detected on CEUS whereas 183 were detected on CECT, there was also significant difference (P < 0.05). In comparison with CECT, the numbers of false positive and false negative intrahepatic recurrences detected on CEUS were 13 and 65, respectively; the sensitivity, specificity, PPV, NPV and overall accuracy of CEUS in detecting new intrahepatic recurrent foci were 77.7%, 92.0%, 92.4%, 76.7% and 84.0%, respectively.

CONCLUSION: The sensitivity of CEUS in detecting LTP and new intrahepatic recurrence after percutaneous ablation therapy is relatively low in comparison with CECT.

Percutaneous ablative therapies of recurrent hepatocellular carcinoma after hepatectomy: proposal of a prognostic model

BACKGROUND

Percutaneous ablative therapies (PAT) are valuable modalities for posthepatectomy recurrent hepatocellular carcinoma (RHCC), but its impact on long-term outcome and prognosis prediction have not been well documented. The present study aimed to analyze prognostic factors and to propose a prognosis-predicting model for RHCC treated with PAT.

METHODS

A total of 288 patients with posthepatectomy RHCC treated with percutaneous ethanol ablation, radiofrequency ablation, microwave ablation, or ethanol ablation combined with radiofrequency ablation were included. Survival and prognostic factors were analyzed. A prognosis-predicting model was created by quantifying and integrating all prognostic factors.

RESULTS

Three-, 5-, and 7-year postablation survival rates were 37.8, 20.7, and 14.2 %, respectively. Multivariate analysis revealed that interval between recurrence and initial hepatectomy, tumor number, largest diameter of tumor, and Barcelona Clinic Liver Cancer stage at hepatectomy were independent prognostic factors for survival. A scoring system for prognostic factors was proposed, and summation of 4 prognostic factors (prognostic score) was ranged from 4 to 10. Prognostic score was classified into three strata, designated as prognostic classes A (score 4 and 5), B (score 6 and 7), and C (≥8). Three-, 5-, and 7-year postablation survival rates were 62.8, 39.4, and 26.9 % in class A, 36.9, 15.5, and 7.2 % in B, and 5.5, 0, and 0 % in class C, respectively (p = 0.00). Three-, 5-, 7-, and 10-year survival rates after initial hepatectomy were 82.4, 66.3, 52.1, and 36.4 % in class A, 51.6, 34.8, 20.7, and 6.6 % in class B, and 11.9, 7.8, 0, and 0 % in class C, respectively (p = 0.00).

CONCLUSIONS

The prognostic model developed in the study could clearly predict different long-term outcomes for patients with posthepatectomy RHCC and thus help decide appropriate therapeutic strategy.

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 ultrasonography (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.

Renal cell carcinoma and renal angiomyolipoma: differential diagnosis with real-time contrast-enhanced ultrasonography

OBJECTIVE

The purpose of this study was to evaluate the usefulness of contrast-enhanced ultrasonography (CEUS) in differentiating renal cell carcinoma (RCC) from renal angiomyolipoma (RAML).

METHODS

One hundred nineteen patients with 126 renal lesions (33 RAMLs and 93 RCCs) who had undergone CEUS were retrospectively studied. All of the lesions were histopathologically or clinical proved. Contrast-enhanced ultrasonography was performed using low-acoustic power modes and a sulfur hexafluoride-filled microbubble contrast agent. The baseline sonograms and CEUS images were retrospectively analyzed in consensus by 2 radiologists. The tumor echogenicity, enhancement patterns, and degree of enhancement at different phases were evaluated. The diagnostic efficacy of CEUS in differentiating the two diseases was computed and compared.

RESULTS

On CEUS, the features of wash-out from hyperenhancement or isoenhancement to hypoenhancement over time (observed in 3.0% of RAMLs and 71.0% of RCCs; P < .001), heterogeneous enhancement (observed in 12.1% of RAMLs and 74.2% of RCCs; P < .001), and an enhanced perilesional rim (observed in 3.0% of RAMLs and 79.6% of RCCs; P < .001) achieved significant difference between RCCs and RAMLs. Early wash-out and heterogeneous enhancement or peritumoral rim enhancement yielded the highest diagnostic capability in differentiating RCC from RAML. The corresponding sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 88.2% (82 of 93), 97.0% (32 of 33), 98.8% (82 of 83), 74.4% (32 of 43), and 90.5% (114 of 126), respectively.

CONCLUSIONS

The CEUS features of early wash-out, heterogeneous enhancement, and an enhanced peritumoral rim highly suggest RCC, whereas homogeneous enhancement and prolonged enhancement are characteristic manifestations of RAML. Contrast-enhanced ultrasonography is valuable in differentiating RCC from RAML.