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Acoustic radiation force impulse elastography for hepatocellular carcinoma-associated radiofrequency ablation  [cached]
Hee-Jin Kwon, Myong-Jin Kang, Jin-Han Cho, Jong-Young Oh, Kyung-Jin Nam, Sang-Yeong Han, Sung Wook Lee
World Journal of Gastroenterology , 2011,
Abstract: AIM: To evaluate the potential usefulness of acoustic radiation force impulse (ARFI) images for evaluation of hepatocellular carcinomas (HCC)-associated radiofrequency ablation.METHODS: From January 2010 to June 2010, a total of 38 patients with HCC including recurred HCCs after RFA underwent ARFI elastography. The brightness of tumor was checked and the shear wave velocity was measured for the quantification of stiffness. According to the brightness, the tumors were classified as brighter, same color and darker compared with adjacent parenchyma. Using the same methods, 8 patients with recurred HCCs after RFA state were evaluated about the brightness compared with adjacent RFA ablation area.RESULTS: In the 38 patients with HCCs, 20 (52.6%) were brighter than surrounding cirrhotic parenchyma. Another 13 (34.2%) were darker. The others (5 cases, 13.2%) were seen as the same color as the adjacent liver parenchyma. Post-RFA lesions were darker than previous tumor and surrounding parenchyma in all 38 cases. However, recurred HCCs were brighter than the treated site in all 8 cases.CONCLUSION: Using ARFI technique is helpful for differential diagnosis in order to detect recurred HCCs more easily in patients with confusing status.
In Vivo Study of Transverse Carpal Ligament Stiffness Using Acoustic Radiation Force Impulse (ARFI) Imaging  [PDF]
Zhilei Liu Shen, D. Geoffrey Vince, Zong-Ming Li
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0068569
Abstract: The transverse carpal ligament (TCL) forms the volar boundary of the carpal tunnel and may provide mechanical constraint to the median nerve, leading to carpal tunnel syndrome. Therefore, the mechanical properties of the TCL are essential to better understand the etiology of carpal tunnel syndrome. The purpose of this study was to investigate the in vivo TCL stiffness using acoustic radiation force impulse (ARFI) imaging. The shear wave velocity (SWV) of the TCL was measured using Virtual Touch IQTM software in 15 healthy, male subjects. The skin and the thenar muscles were also examined as reference tissues. In addition, the effects of measurement location and ultrasound transducer compression on the SWV were studied. The SWV of the TCL was dependent on the tissue location, with greater SWV values within the muscle-attached region than those outside of the muscle-attached region. The SWV of the TCL was significantly smaller without compression (5.21 ± 1.08 m/s) than with compression (6.62 ± 1.18 m/s). The SWV measurements of the skin and the thenar muscles were also affected by transducer compression, but to different extents than the SWV of the TCL. Therefore to standardize the ARFI imaging procedure, it is recommended that a layer of ultrasound gel be maintained to minimize the effects of tissue compression. This study demonstrated the feasibility of ARFI imaging for assessing the stiffness characteristics of the TCL in vivo, which has the potential to identify pathomechanical changes of the tissue.
Usefulness of Noninvasive Predictors of Oesophageal Varices in Black African Cirrhotic Patients in C?te d'Ivoire (West Africa)  [PDF]
Alassan Kouamé Mahassadi,Fulgence Yao Bathaix,Constant Assi,Aboubacar Demba Bangoura,Emile Allah-Kouadio,Henriette Ya Kissi,Abdoulaye Touré,Stanislas Doffou,Issa Konaté,Alain Koffi Attia,Mathieu Benoit Camara,Thérèse Aya Ndri-Yoman
Gastroenterology Research and Practice , 2012, DOI: 10.1155/2012/216390
Abstract: Aims. To determine the usefulness of platelet count (PC), spleen diameter (SD) and platelet count/spleen diameter ratio (PC/SD ratio) for the prediction of oesophageal varices (OV) and large OV in black African patients with cirrhosis in C?te d’Ivoire. Materials and Methods. Study was conducted in a training sample (111 patients) and in a validation sample (91 patients). Results. Factors predicting OV were sex: ( , ), PC (OR = 12.4, ), SD (OR = 1.04, ) in the training sample. The AUROCs (±SE) of the model (cutoff ≥ 0.6), PC (cutoff < 110500), SD (cutoff > 140) and PC/SD ratio (cutoff ≤ 868) were, respectively; 0.879 ± 0.04, 0.768 ± 0.06, 0.679 ± 0.06, 0.793 ± 0.06. For the prediction of large OV, the model’s AUROC (0.850 ± 0.05) was superior to that of PC (0.688 ± 0.06), SD (0.732 ± 0.05) and PC/SD ratio (0.752 ± 0.06). In the validation sample, with PC, PC/SD ratio and the model, upper digestive endoscopy could be obviated respectively in 45.1, 45.1, and 44% of cirrhotic patients. Prophylactic treatment with beta blockers could be started undoubtedly respectively in 36.3, 41.8 and 28.6% of them as having large OV. Conclusion. Non-invasive means could be used to monitor cirrhotic patients and consider treatment in African regions lacking endoscopic facilities. 1. Introduction Oesophageal varices (OV) due to portal hypertension are a major concern in cirrhotic patients because of the risk of bleeding and related high mortality [1]. The prevalence of OV in newly diagnosed cirrhotic patients is approximately 60–80% and the 1-year rate of first variceal bleeding is approximately 5% for small OV and 15% for large OV [1, 2]. The determination of the presence of OV by upper digestive endoscopy is therefore mandatory in patients with cirrhosis at diagnosis [3]. For long-term followup, guidelines recommend monitoring of cirrhotic patients by routine endoscopy for the detection of the development of OV and to initiate prophylactic measures to prevent the bleeding of OV when they become large [3, 4]. Endoscopy is however a costly, invasive, and time-consuming procedure [5]. It is obvious that in most African countries monitoring cirrhotic patients with endoscopy even at baseline or during followup is a challenge for clinicians due to the lack or not widely implemented and accessible endoscopy units [6]. Several studies have reported that platelet count (PC), spleen diameter (SD) and their ratio (PC/SD), portal vein diameter, and Child-Pugh score were strongly associated with the presence of OV in cirrhotic patients [7–10]. Predictive models derived from these
Value of acoustic radiation force impulse elastography for the assessment of ascites syndrome  [cached]
Simona Bota,Ioan Sporea,Roxana ?irli,Alina Popescu
World Journal of Radiology , 2011, DOI: 10.4329/wjr.v3.i8.205
Abstract: AIM: To assess the feasibility of performing acoustic radiation force impulse (ARFI) elastography in patients with ascites and its predictive value for the cirrhotic or non-cirrhotic etiology of ascites. METHODS: Our study included 153 patients with ascites, mean age 58.8 ± 13.1 years. One hundred and fifteen (75.2%) patients had ascites in the context of cirrhosis, 29 (18.9%) had non-cirrhotic ascites (diagnosed by clinical, ultrasound, endoscopic and/or laparoscopic criteria) and in 9 (5.9%) cases we could not establish the etiology of ascites. We performed 10 ARFI measurements and the median value was calculated and expressed in meters/second (m/s). Among the 29 patients with non-cirrhotic ascites were included: 20 laparoscopically demonstrated peritoneal carcinomatosis with histological confirmation, 7 acute pancreatitis with ascites which later resolved, and one case each of lymphatic ascites and ascites in the context of a liver abscess. In 11 of the 20 patients with peritoneal carcinomatosis, the liver structure was homogenous in the ultrasound examination and in 9 patients the ultrasound exam revealed liver metastases. RESULTS: We could not obtain valid ARFI measurements in 5 patients (3.2%). The mean liver stiffness measurements by means of ARFI were statistically significantly higher in patients with cirrhotic ascites than in those with non-cirrhotic ascites: 3.04 ± 0.70 vs 1.45 ± 0.59 m/s (P < 0.001). For a cut-off value of 1.8 m/s for predicting cirrhosis (and ascites in the context of cirrhosis), as obtained in a previous study, ARFI had 98.1% sensitivity, 86.2% specificity, 96.4% positive predictive value, 92.5% negative predictive value and 95.6% accuracy for predicting cirrhotic ascites. For a cut-off value of 1.9 m/s the accuracy was 94.9% and for a 2 m/s cut-off value it was 92.8%. CONCLUSION: ARFI elastography is feasible in most patients with ascites and has a very good predictive value for the cirrhotic or non-cirrhotic etiology of ascites.
Non-Invasive Evaluation of Cystic Fibrosis Related Liver Disease in Adults with ARFI, Transient Elastography and Different Fibrosis Scores  [PDF]
Thomas Karlas, Marie Neuschulz, Annett Oltmanns, Andrea Güttler, David Petroff, Hubert Wirtz, Jochen G. Mainz, Joachim M?ssner, Thomas Berg, Michael Tr?ltzsch, Volker Keim, Johannes Wiegand
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0042139
Abstract: Background Cystic fibrosis-related liver disease (CFLD) is present in up to 30% of cystic fibrosis patients and can result in progressive liver failure. Diagnosis of CFLD is challenging. Non-invasive methods for staging of liver fibrosis display an interesting diagnostic approach for CFLD detection. Aim We evaluated transient elastography (TE), acoustic radiation force impulse imaging (ARFI), and fibrosis indices for CFLD detection. Methods TE and ARFI were performed in 55 adult CF patients. In addition, AST/Platelets-Ratio-Index (APRI), and Forns' score were calculated. Healthy probands and patients with alcoholic liver cirrhosis served as controls. Results Fourteen CF patients met CFLD criteria, six had liver cirrhosis. Elastography acquisition was successful in >89% of cases. Non-cirrhotic CFLD individuals showed elastography values similar to CF patients without liver involvement. Cases with liver cirrhosis differed significantly from other CFLD patients (ARFI: 1.49 vs. 1.13 m/s; p = 0.031; TE: 7.95 vs. 4.16 kPa; p = 0.020) and had significantly lower results than individuals with alcoholic liver cirrhosis (ARFI: 1.49 vs. 2.99 m/s; p = 0.002). APRI showed the best diagnostic performance for CFLD detection (AUROC 0.815; sensitivity 85.7%, specificity 70.7%). Conclusions ARFI, TE, and laboratory based fibrosis indices correlate with each other and reliably detect CFLD related liver cirrhosis in adult CF patients. CF specific cut-off values for cirrhosis in adults are lower than in alcoholic cirrhosis.
Is ARFI elastography reliable for predicting fibrosis severity in chronic HCV hepatitis?  [cached]
Ioan Sporea,Roxana ?irli,Simona Bota,Carmen Fierbin?eanu-Braticevici
World Journal of Radiology , 2011, DOI: 10.4329/wjr.v3.i7.188
Abstract: AIM: To determine whether acoustic radiation force impulse (ARFI) elastography is a reliable method for predicting fibrosis severity in patients with chronic hepatitis C virus (HCV) hepatitis. METHODS: We performed a multicenter study including 274 subjects with HCV chronic hepatitis in which we compared ARFI with liver biopsy (LB). In each patient we performed LB (evaluated according to the Metavir score) and ARFI measurements (using a Siemens Acuson S2000 ultrasound system: 10 valid measurements were performed and median values were calculated and expressed in meters/second (m/s). RESULTS: A direct, strong, correlation (Spearman r = 0.707) was found between ARFI measurements and fibrosis (P < 0.0001). For predicting the presence of fibrosis (F ≥ 1 Metavir), significant fibrosis (F ≥ 2), severe fibrosis (F ≥ 3) and cirrhosis (F = 4), the cut-off values of 1.19, 1.21, 1.58 and 1.82 m/s were determined, respectively, liver stiffness measurements had 73%, 84%, 84% and 91% Se respectively; 93%, 91%, 94%, 90% Sp, respectively; with AUROCs of 0.880, 0.893, 0.908 and 0.937, respectively. CONCLUSION: ARFI measurement is a reliable method for predicting the severity of fibrosis in HCV patients
Virtual Touch Tissue Quantification of Acoustic Radiation Force Impulse: A New Ultrasound Elastic Imaging in the Diagnosis of Thyroid Nodules  [PDF]
Yi-Feng Zhang, Hui-Xiong Xu, Yong He, Chang Liu, Le-Hang Guo, Lin-Na Liu, Jun-Mei Xu
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0049094
Abstract: Objective Virtual touch tissue quantification (VTQ) of acoustic radiation force impulse (ARFI) is a new quantitative technique to measure tissue stiffness. The study was aimed to assess the usefulness of VTQ in the diagnosis of thyroid nodules. Methods 173 pathologically proven thyroid nodules in 142 patients were included and all were examined by conventional ultrasound (US), conventional elasticity imaging (EI) and VTQ of ARFI. The tissue stiffness for VTQ was expressed as shear wave velocity (SWV) (m/s). Receiver-operating characteristic curve (ROC) analyses were performed to assess the diagnostic performance. Intra- and inter-observer reproducibility of VTQ measurement was assessed. Results The SWVs of benign and malignant thyroid nodules were 2.34±1.17 m/s (range: 0.61–9.00 m/s) and 4.82±2.53 m/s (range: 2.32–9.00 m/s) respectively (P<0.001). The mean SWV ratios between each nodule and the adjacent thyroid tissue were 1.19±0.67 (range: 0.31–6.87) for benign and 2.50±1.54 (range: 0.85–6.69) for malignant nodules (P<0.001). ROC analyses indicated that the area under the curve was 0.861 (95% CI : 0.804, 0.918) (P<0.001) for SWV and 0.831(95% CI : 0.761, 0.900)(P<0.001) for the SWV ratio. The cutoff points for the differential diagnosis were 2.87 m/s for SWV and 1.59 for SWV ratio. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value for EI were 65.9%, 66.7%, 66.5%, 40.3%, and 85.1%, respectively, and were 63.6%–75%, 82.2%–88.4%, 80.3%–82.1%, 58.9%–65.1%, and 87.7%–90.5%, respectively, for VTQ. The diagnostic value of VTQ is the highest for nodules >20 mm and lowest for those ≤10 mm. The correlation coefficients were 0.904 for intraobserver measurement and 0.864 for interobserver measurement. Conclusions VTQ of ARFI provides quantitative and reproducible information about the tissue stiffness, which is useful for the differentiation between benign and malignant thyroid nodules. The diagnostic performance of VTQ is higher than that of conventional EI.
ARFI elastography for the evaluation of diffuse thyroid gland pathology: Preliminary results  [cached]
Ioan Sporea,Roxana Sirli,Simona Bota,Mihaela Vlad
World Journal of Radiology , 2012, DOI: 10.4329/wjr.v4.i4.174
Abstract: AIM: To assess whether acoustic radiation force impulse (ARFI) elastography can differentiate normal from pathological thyroid parenchyma. METHODS: We evaluated 136 subjects (mean age 45.8 ± 15.6 years, 106 women and 30 men): 44 (32.3%) without thyroid pathology, 48 (35.3%) with Basedow-Graves’ disease (GD), 37 (27.2%) with chronic autoimmune thyroiditis (CAT; diagnosed by specific tests), 4 (2.9%) with diffuse thyroid goiter and 3 (2.2%) cases with thyroid pathology induced by amiodarone. In all patients, 10 elastographic measurements were made in the right thyroid lobe and 10 in the left thyroid lobe, using a 1-4.5 MHZ convex probe and a 4-9 MHz linear probe, respectively. Median values were calculated for thyroid stiffness and expressed in meters/second (m/s). RESULTS: Thyroid stiffness (TS) assessed by means of ARFI in healthy subjects (2 ± 0.40 m/s) was significantly lower than in GD (2.67 ± 0.53 m/s) (P < 0.0001) and CAT patients (2.43 ± 0.58 m/s) (P = 0.0002), but the differences were not significant between GD vs CAT patients (P = 0.053). The optimal cut-off value for the prediction of diffuse thyroid pathology was 2.36 m/s. For this cut-off value, TS had 62.5% sensitivity, 79.5% specificity, 87.6% predictive positive value, 55.5% negative predictive value and 72.7% accuracy for the presence of diffuse thyroid gland pathology (AUROC = 0.804). There were no significant differences between the TS values obtained with linear vs convex probes and when 5 vs 10 measurements were taken in each lobe (median values). CONCLUSION: ARFI seems to be a useful method for the assessment of diffuse thyroid gland pathology.
Comparison of Diagnostic Efficacy of Contrast-Enhanced Ultrasound, Acoustic Radiation Force Impulse Imaging, and Their Combined Use in Differentiating Focal Solid Thyroid Nodules  [PDF]
Jin Deng, Ping Zhou, Shuang-ming Tian, Lu Zhang, Jia-le Li, Ying Qian
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0090674
Abstract: Background A key limitation of conventional ultrasound (US) includes poor differentiation of benign from malignant thyroid nodules. Contrast-enhanced US (CEUS) and acoustic radiation force impulse (ARFI) could provide better characterization of focal thyroid nodules; however, no studies have compared their efficacies. Objective To evaluate the diagnostic efficacy of conventional US,CEUS, ARFI, and their combined use in differentiating focal solid thyroid nodules. Methods One-hundred-forty-six Chinese patients with 175 thyroid nodules (119 benign and 56 malignant) were prospectively enrolled. Each patients underwent conventional US, CEUS and ARFI, respectively. The diagnostic performance of the conventional US, CEUS, ARFI, combined use of either CEUS or ARFI and combined use of the three modalities were assessed and compared using Pathological diagnosis (histological/cytological) as the reference method. Results There were no significant differences between individual groups (CEUS vs US, P = 0.279, ARFI vs US, P = 0.372, CEUS vs ARFI, P = 0.849), combined use of US and CEUS or combined use of US and ARFI yielded significant difference compared to US. (combination of US & CEUS vs US, P = 0.021; combination of US & ARFI vs US, P = 0.036). The combination of three modalities significantly improved the diagnostic accuracy compared with either combination of conventional US and CEUS or combination of conventional US and ARFI (P = 0.045 and P = 0.027, respectively). Conclusions CEUS and ARFI can be used as an additional tool in the diagnostic work up of thyroid nodules. The combination of CEUS with ARFI can significantly improve the diagnostic accuracy.
Acoustic Radiation Force Impulse Imaging for Differentiation of Thyroid Nodules  [PDF]
Joerg Bojunga, Nina Dauth, Christian Berner, Gesine Meyer, Katharina Holzer, Lisa Voelkl, Eva Herrmann, Hartmut Schroeter, Stefan Zeuzem, Mireen Friedrich-Rust
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0042735
Abstract: Background Acoustic Radiation Force Impulse (ARFI)-Imaging is an ultrasound-based elastography method enabling quantitative measurement of tissue stiffness. The aim of the present study was to evaluate sensitivity and specificity of ARFI-imaging for differentiation of thyroid nodules and to compare it to the well evaluated qualitative real-time elastography (RTE). Methods ARFI-imaging involves the mechanical excitation of tissue using acoustic pulses to generate localized displacements resulting in shear-wave propagation which is tracked using correlation-based methods and recorded in m/s. Inclusion criteria were: nodules ≥5 mm, and cytological/histological assessment. All patients received conventional ultrasound, real-time elastography (RTE) and ARFI-imaging. Results One-hundred-fifty-eight nodules in 138 patients were available for analysis. One-hundred-thirty-seven nodules were benign on cytology/histology, and twenty-one nodules were malignant. The median velocity of ARFI-imaging in the healthy thyroid tissue, as well as in benign and malignant thyroid nodules was 1.76 m/s, 1.90 m/s, and 2.69 m/s, respectively. While no significant difference in median velocity was found between healthy thyroid tissue and benign thyroid nodules, a significant difference was found between malignant thyroid nodules on the one hand and healthy thyroid tissue (p = 0.0019) or benign thyroid nodules (p = 0.0039) on the other hand. No significant difference of diagnostic accuracy for the diagnosis of malignant thyroid nodules was found between RTE and ARFI-imaging (0.74 vs. 0.69, p = 0.54). The combination of RTE with ARFI did not improve diagnostic accuracy. Conclusions ARFI can be used as an additional tool in the diagnostic work up of thyroid nodules with high negative predictive value and comparable results to RTE.
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