Primary biliary cirrhosis degree assessment by acoustic radiation force impulse imaging and hepatic fibrosis indicators

AIM: To evaluate the assessment of primary biliary cirrhosis degree by acoustic radiation force impulse imaging (ARFI) and hepatic fibrosis indicators. METHODS: One hundred and twenty patients who developed liver cirrhosis secondary to primary biliary cirrhosis were selected as the observation group, with the degree of patient liver cirrhosis graded by Child-Pugh (CP) score. Sixty healthy individuals were selected as the control group. The four indicators of hepatic fibrosis were detected in all research objects, including hyaluronic acid (HA), laminin (LN), type III collagen (PC III), and type IV collagen (IV-C). The liver parenchyma hardness value (LS) was then measured by ARFI technique. LS and the four indicators of liver fibrosis (HA, LN, PC III, and IV-C) were observed in different grade CP scores. The diagnostic value of LS and the four indicators of liver fibrosis in determining liver cirrhosis degree with PBC, whether used alone or in combination, were analyzed by receiver operating characteristic (ROC) curve. RESULTS: LS and the four indicators of liver fibrosis within the three classes (A, B, and C) of CP scores in the observation group were higher than in the control group, with C class > B class > A class; the differences were statistically significant (P < 0.01). Although AUC values of LS within the three classes of CP scores were higher than in the four indicators of liver fibrosis, sensitivity and specificity were unstable. The ROC curves of LS combined with the four indicators of liver fibrosis revealed that: AUC and sensitivity in all indicators combined in the A class of CP score were higher than in LS alone, albeit with slightly decreased specificity; AUC and specificity in all indicators combined in the B class of CP score were higher than in LS alone, with unchanged sensitivity; AUC values (0.967), sensitivity (97.4%), and specificity (90%) of all indicators combined in the C class of CP score were higher than in LS alone (0.936, 92.1%, 83.3%). CONCLUSION: The diagnostic value of PBC cirrhosis degree in liver cirrhosis degree assessment by ARFI combined with the four indicators of serum liver fibrosis is of satisfactory effectiveness and has important clinical application value.

Evaluation of acoustic radiation force impulse imaging for determination of liver stiffness using transient elastography as a reference

AIM: To evaluate cut-off values and performance of acoustic radiation force impulse imaging (ARFI) using transient elastography [FibroScan■ (FS)] as a reference. METHODS: Six hundred and six patients were enrolled in this study.All patients underwent liver stiffness measurement with FS (FS-LS) and ARFI (with shear wave velocity quantification; ARFI-SWV) and the performance of ARFI in comparison to FS was determined. Sixtyeight patients underwent liver biopsy. RESULTS: Significantly higher success rates for the determination of liver stiffness were found using ARFI as compared to FS [604/606 (99.7%) vs 482/606 (79.5%); P < 0.001]. ARFI-SWV correlated significantly with FS-LS (r = 0.920, P < 0.001). ARFI-SWV increased significantly with the stage of fibrosis (1.09 ± 0.13 m/s for patients with no significant fibrosis (FS-LS < 7.6 kPa); 1.46 ± 0.27 m/s for patients with significant liver fibrosis (7.6 < FS-LS ≤ 13.0 kPa); and 2.55 ± 0.77 m/s for patients with liver cirrhosis (FS-LS > 13.0 kPa)). ARFI-SWV cut-off values were identified for no significant fibrosis (1.29 m/s; sensitivity 91.4% and specificity 92.6%) and for liver cirrhosis (1.60 m/s; sensitivity 92.3% and specificity 96.5%). The optimal cut-off value for predicting liver fibrosis (F ≥ 2) was 1.32 m/s (sensitivity 87.0% and specificity 80.0%) and for liver cirrhosis (F4) 1.62 m/s (sensitivity 100% and specificity 85.7%), for patients who underwent liver biopsy. An excellent inter-and intraobserver reproducibility was observed for ARFI-SWV determinations. CONCLUSION: An ARFI-SWV cut-off value of 1.29 m/s seems to be optimal for patients with no significant liver fibrosis and 1.60 m/s for patients with liver cirrhosis.

Application of acoustic radiation force impulse imaging for the evaluation of focal liver lesion elasticity

BACKGROUND: Acoustic radiation force impulse (ARFI) imaging is a new elastography method for the evaluation of tissue stiffness. This study aims to evaluate the performance of ARFI in noninvasive assessment of the tissue stiffness of focal liver lesion (FLL) and to explore its potential value in the differential diagnosis of FLL. METHODS: ARFI was performed in 140 patients with 154 FLLs, which included 28 hemangiomas (ANGIs), 14 focal nodular hyperplasias (FNHs), 61 hepatocellular carcinomas (HCCs), 39 metastases and 12 cholangiocellular carcinomas (CCCs). Virtual touch tissue quantification (VTTQ) values were obtained, analyzed and compared. The area under the receiver operating characteristic curve (AUROC) and optimal cut-off values were obtained using a receiver operating characteristic (ROC) curve analysis to assess diagnostic performance. All cases were definitively diagnosed using histopathology, CT, MRI or contrast-enhanced ultrasound. RESULTS: The VTTQ median values of ANGI, FNH, HCC metastasis and CCC were 1.30, 1.80, 2.52, 3.08 and 3.89 m/s respectively. A significant increase in the VTTQ values of different lesions was observed: ANGI【FNH【HCC【metastasis 【CCC (P【0.001). The AUROC (95% CI) of VTTQ values was 0.94 (0.90-0.98) for ANGI, 0.91 (0.87-0.96) for malignant lesions and 0.87 (0.79-0.94) for CCC. The sensitivity and specificity for ANGI (86.5%, 89.3%, respectively), malignancy (81.3% 92.9%, respectively), and CCC (91.7%, 72.5%, respectively) were associated with VTTQ cut-off values of 1.76, 2.22 and 3.00 m/s respectively.CONCLUSIONS: ARFI can accurately and objectively assess the elasticity of lesions by obtaining the shear wave elastic value of FLL with VTTQ. Therefore, ARFI is a novel, simple, noninvasive and useful diagnostic method for the characterization of FLL.

A Modified Monte Carlo Model of Speckle Tracking of Shear Wave Induced by Acoustic Radiation Force for Acousto-Optic Elasticity Imaging

A modified Monte Carlo model of speckle tracking of shear wave propagation in scattering media is proposed. The established Monte Carlo model mainly concerns the variations of optical electric field and speckle. The two- dimensional intensity distribution and the time evolution of speckles in different probe locations are obtained. The fluctuation of speckle intensity tracks the acoustic-radiation-force shear wave propagation, and especially the reduction of speckle intensity implies attenuation of shear wave. Then, the shear wave velocity is estimated quantitatively on the basis of the time-to-peak algorithm and linear regression processing. The results reveal that a smaller sampling interval yields higher estimation precision and the shear wave velocity is estimated more efficiently by using speckle intensity difference than by using speckle contrast difference according to the estimation error. Hence, the shear wave velocity is estimated to be 2.25 m/s with relatively high accuracy for the estimation error reaches the minimum （0.071）.

Preliminary results of acoustic radiation force impulses (ARFI) ultrasound imaging of solid suspicious breast lesions

Objective： The aim of our study was to make the qualitative and quantitative analysis to breast lesions using acoustic radiation force impulses （ARFI）, and assess the diagnostic value of ARFI for differentiation between benign and malignant solid breast masses, meanwhile evaluate the influences of ARFI with breast imaging reporting and data system （BI-RADS） of suspicious masses. Methods： Seventy-five women with 86 breast lesions underwent conventional breast ultra- sound examination. Then B-mode BI-RADS features and assessments were recorded and standard breast US supplemented by ARFI elastographic examination were repeated. The data were recorded and analyzed as following： area ratio of breast lesion, the shear-wave velocity, the ratio of the shear-wave velocity between lesions and surrounding normal tissues, and according to the elastographic data reconsidered the BI-RADS category, all the results have been correlated with pathological results and make statistical evaluations of ARFI for differentiation between benign and malignant solid breast masses. Meantime our study has correlated the adjusted BI-RADS category of suspicious breast lesions with the pathological results and made assessment. Results： Thirty-eight patients were malignant breast carcinoma （31 invasive ductal carcinoma, 5 intraductal carcinoma in situ, 2 medullary carcinoma, 2 invasive Iobular carcinoma）, 48 patients were benign breast lesions （23 fibroadenoma, 12 benign nodular hyperplasia, 5 phyllodes tumor, 6 adenosis, 2 intraductal papilloma）. Underwent conventional breast ultrasound exam, 42 cases were BI-RADS category 3, 23 cases were BI-RADS category 4. When adding elastographic data, 46 cases were BI-RADS category 3 and 20 cases were BI-RADS category 4. Compared with pathological results showed for both the specificity of BIRADS features and the area under ROC curve has risen. Virtual touch tissue imaging （VTI） and virtual touch tissue quantification （VTQ） data showed the area ratio （AR） between elastographic lesions area and B-mode lesions area, SWV （maximal shear-wave velocity of lesions）, R-SWV （shear-wave velocity ratio between lesions and surrounding normal tissues） in benign breast lesions were lower than those in malignant lesions which has statistical significance and the cut-off point were 1.1,4.65 m/s, 5.18 respectively. Conclusion： The ARFI elastography can provide the reliable qualitative and quantitative analysis about hardness of breast lesions, supply the new BI-RADS category features to suspicious breast masses and serve as an effective diagnostic tool for differentiation between benign and malignant solid masses.

Noninvasive diagnosis of cirrhosis:A review of different imaging modalities

Progressive hepatic fibrosis can lead to cirrhosis,so its early detection is fundamental.Staging fibrosis is also critical for prognosis and management.The gold standard for these aims is liver biopsy,but it has several drawbacks,as it is invasive,expensive,has poor acceptance,is prone to inter observer variability and sampling errors,has poor repeatability,and has a risk of complications and mortality.Therefore,non-invasive imaging tests have been developed.This review mainly focuses on the role of transient elastography,acoustic radiation force impulse imaging,and magnetic resonance-based methods for the noninvasive diagnosis of cirrhosis.

Ultrasound elastographic techniques in focal liver lesions

Elastographic techniques are new ultrasound-based imaging techniques developed to estimate tissue deformability/stiffness. Several ultrasound elastographic approaches have been developed, such as static elastography, transient elastography and acoustic radiation force imaging methods, which include point shear wave and shear wave imaging elastography. The application of these methods in clinical practice aims at estimating the mechanical tissues properties. One of the main settings for the application of these tools has been liver stiffness assessment in chronic liver disease, which has been studied mainly using transient elastography. Another field of application for these techniques is the assessment of focal lesions, detected by ultrasound in organs such as pancreas, prostate, breast, thyroid, lymph nodes. Considering the frequency and importance of the detection of focal liver lesions through routine ultrasound, some studies have also aimed to assess the role that elestography can play in studying the stiffness of different types of liver lesions, in order to predict their nature and thus offer valuable non-invasive methods for the diagnosis of liver masses.

Non-invasive diagnosis of hepatitis B virus-related cirrhosis

Chronic hepatitis B(CHB)infection is a major public health problem associated with significant morbidity and mortality worldwide.Twenty-three percent of patients with CHB progress naturally to liver cirrhosis,which was earlier thought to be irreversible.However,it is now known that cirrhosis can in fact be reversed by treatment with oral anti-nucleotide drugs.Thus,early and accurate diagnosis of cirrhosis is important to allow an appropriate treatment strategy to be chosen and to predict the prognosis of patients with CHB.Liver biopsy is the reference standard for assessment of liver fibrosis.However,the method is invasive,and is associated with pain and complications that can be fatal.In addition,intra-and inter-observer variability compromises the accuracy of liver biopsy data.Only small tissue samples are obtained and fibrosis is heterogeneous in such samples.This confounds the two types of observer variability mentioned above.Such limitations have encouraged development of non-invasive methods for assessment of fibrosis.These include measurements of serum biomarkers of fibrosis;and assessment of liver stiffness via transient elastography,acoustic radiation force impulse imaging,real-time elastography,or magnetic resonance elastography.Although significant advances have been made,most work to date has addressed the diagnostic utility of these techniques in the context of cirrhosis caused by chronic hepatitis C infection.In the present review,we examine the advantages afforded by use of non-invasive methods to diagnose cirrhosis in patients with CHB infections and the utility of such methods in clinical practice.