Contrast-enhanced ultrasound (CEUS) for the evaluation of focal liver lesions - a prospective multicenter study of its usefulness in clinical practice.

PURPOSE: To assess the value of contrast-enhanced ultrasound (CEUS) for differentiating malignant from benign focal liver lesions (FLLs) and for diagnosing different FLL types. MATERIAL AND METHODS: CEUS performed in 14 Romanian centers was prospectively collected between February 2011 and June 2012. The inclusion criteria were: age > 18 years; patients diagnosed with 1 - 3 de novo FLLs on B-mode ultrasound; reference method (computed tomography (CT), magnetic resonance imaging (MRI) or biopsy) available; patient's informed consent. FLL lesions were characterized during CEUS according to the European Federation of Societies for Ultrasound in Medicine and Biology guidelines. For statistical analysis, indeterminate FLLs at CEUS were rated as false classifications. RESULTS: A total number of 536 cases were included in the final analysis, 344 malignant lesions (64.2 %) and 192 benign lesions (35.8 %). The reference method was: CT/MRI - 379 cases (70.7 %), pathological exam - 150 cases (27.9 %) and aspiration of liver abscesses - 7 cases (1.4 %). CEUS was conclusive in 89.3 % and inconclusive in 10.7 % of cases. To differentiate between malignant and benign FLLs, CEUS had 85.7 % sensitivity, 85.9 % specificity, 91.6 % positive predictive value, 77.1 % negative predictive value and 85.8 % accuracy. The CEUS accuracy for differentiation between malignant and benign liver lesions was similar in tumors with diameter ≤ 2 cm and those with diameter > 2 cm. CONCLUSION: CEUS represents a useful method in clinical practice for differentiating between malignant and benign FLLs detected on standard ultrasonography, and the results of this study are in concordance with previous multicenter studies: DEGUM (Germany) and STIC (France).

Hepatic elastography for the assessment of liver fibrosis--present and future.

Liver Biopsy was considered the "gold standard" for severity assessment in chronic hepatitis for a very long time. In recent years, non invasive methods were developed in order to replace it. Among them ultrasound based elastographic methods: Transient Elastography (already validated and replacing liver biopsy in some countries), Real Time Tissue Elastography and Acoustic Radiation Force Impulse Elastography (currently under evaluation) and Shear Wave Elastography (the newest one). As an alternative to liver biopsy, the development of all these non invasive methods for dynamic evaluation of liver fibrosis will decrease the need for LB, making clinical care safer and more convenient for patients with liver diseases.

Thyroid stiffness assessment by acoustic radiation force impulse elastography (ARFI).

PURPOSE: To evaluate and compare the values of thyroid tissue elasticity in subjects without known thyroid pathology, in patients with Graves' disease and with chronic autoimmune thyroiditis (CAT). PATIENTS AND METHODS: We performed a prospective study that included 74 subjects, 23 without thyroid pathology, 29 with Graves' disease and 22 with CAT (diagnosed by specific tests). In all patients, 10 elastographic measurements were performed in the right thyroid lobe (RTL) and 10 in the left thyroid lobe (LTL) using a 2-6 MHz convex probe. Median values were calculated for each thyroid lobe, measured in meters/second (m/sec). We calculated a mean ARFI value from measurements made in the RTL and LTL. RESULTS: Thyroid stiffness was statistically significant lower in normal subjects vs. those with Graves' disease (2.07±0.44 m/sec vs. 2.82±0.47 m/sec, p<0.001) and with CAT (2.07±0.44 m/sec vs. 2.49±0.48 m/sec, p=0.004). We also found a statistically significant difference between subjects without thyroid pathology and those with autoimmune thyroid pathology (Graves' disease and CAT) (2.07±0.44 m/sec vs. 2.68±0.50 m/sec, p<0.001). CONCLUSION: ARFI seems to be a useful method for the evaluation of diffuse thyroid gland pathology and is able to predict with sufficient accuracy the presence of thyroid diffuse diseases (AUROC=0.80).

Acoustic radiation force impulse elastography as compared to transient elastography and liver biopsy in patients with chronic hepatopathies.

PURPOSE: To compare two methods of noninvasive assessment: transient elastography (TE) and acoustic radiation force impulse elastography (ARFI). PATIENTS AND METHODS: Our study included 114 subjects: 38 healthy volunteers, (considered to have no fibrosis - F 0) and 76 patients with chronic liver disease: 53 who had undergone liver biopsy (LB) (7 with F 1, 24 with F 2, 22 with F 3 Metavir) and 23 previously diagnosed with cirrhosis (F4 Metavir). In each patient we performed a liver stiffness measurement by means of TE and ARFI. ARFI (shear wave velocity quantification) was performed at 3 points: at 0 - 1 cm, at 1 - 2 cm and at 2 - 3 cm under the capsule. For each depth, 5 valid measurements were made, and a median value was calculated, measured in m/sec. RESULTS: A direct, strong, linear correlation (Spearman rho = 0.848) was found between TE and the stage of fibrosis (p < 0.001). A significant, direct correlation was found between ARFI measurements made 1 - 2 cm and 2 - 3 cm below the liver capsule and the severity of fibrosis (rho = 0.675 and 0.714 respectively). The subcapsularly measured ARFI values showed a poor correlation with fibrosis (rho = 0.469). The best test for predicting significant fibrosis (F ≥ 2) was TE, with the area under receiver-operating characteristic curve (AUROC) 0.908, significantly larger than the AUROCs for ARFI. If only ARFI is considered, measurements made 1 - 2 and 2 - 3 cm below the capsule have the best predictive value, with AUROCs not significantly different from each other (0.767 and 0.731, respectively). For predicting fibrosis (F > 0), TE had the best predictive value: optimized cut-off 5.65 kPa (AUROC -0.898). For ARFI, the cut-offs were: 1.4 m/sec, AUROC -0.747 (1 - 2 cm), and 1.26 m/sec AUROC -0.721 (2 - 3 cm). For predicting cirrhosis (F = 4 Metavir), the optimized cut-offs were: TE -12.9 kPa (AUROC -0.994); ARFI - 1.78 m/sec for measurements made 2 - 3 cm below the capsule, AUROC - 0.951. CONCLUSION: At present, liver elasticity evaluation by means of ARFI is not superior to TE for the assessment of liver fibrosis. For ARFI, the most reliable results are obtained if measurements are made 1 - 2 and 2 - 3 cm below the liver capsule. ARFI is an accurate test for the diagnosis of cirrhosis.

What did we learn from the first 3,459 cases of liver stiffness measurement by transient elastography (FibroScan®)?

PURPOSE: Chronic viral hepatopathies can be evaluated through invasive or noninvasive methods. The aim of this paper was to assess the indications and results of transient elastographic (TE) evaluation of the liver in patients with chronic viral hepatitis and cirrhosis. MATERIALS AND METHODS: We retrospectively assessed all the liver stiffness measurements (LSM) (FibroScan®) performed over a two-year period (2007 - 2009). RESULTS: 3,459 TE evaluations were made mainly for the assessment of: HCV hepatitis, HBV infection (chronic hepatitis and inactive HBV carriers), biviral hepatitis (B + C or B + D), cirrhosis and in 176 normal subjects (to establish the normal values of LSM). From the 3,459 FS evaluations, we could not obtain valid LSM in 183 cases (5.3 %). 93.9 % of the patients in the failure group were overweight (BMI > 25 kg/m²). In 527 cases (16 %) the SR (success rate = number of valid measurements/total number of measurements) was < 60 %. TE reproducibility was analyzed in 287 cases. The ICCs for the three operators were 0.985, 0.949, and 0.874 respectively, and the overall ICC was 0.982. 596 cases of cirrhosis were evaluated. A cut-off value of 23.3kPa was found to predict the presence of at least grade 2 esophageal varices. CONCLUSION: LSM by means of TE is a promising noninvasive evaluation method, which can be used in numerous clinical situations, some in which its value is well established (suspicion of LC, predicting significant fibrosis) and some in which its value is less known (HBV chronic hepatitis, inactive HBV carriers or severity of portal hypertension).