Vito Cantisani

EFSUMB guidelines and recommendations on the clinical use of ultrasound elastography. Part 1: Basic principles and technology.

The technical part of these Guidelines and Recommendations, produced under the auspices of EFSUMB, provides an introduction to the physical principles and technology on which all forms of current commercially available ultrasound elastography are based. A difference in shear modulus is the common underlying physical mechanism that provides tissue contrast in all elastograms. The relationship between the alternative technologies is considered in terms of the method used to take advantage of this. The practical advantages and disadvantages associated with each of the techniques are described, and guidance is provided on optimisation of scanning technique, image display, image interpretation and some of the known image artefacts.

EFSUMB Guidelines and Recommendations on the Clinical Use of Ultrasound Elastography. Part 2: Clinical Applications

The clinical part of these Guidelines and Recommendations produced under the auspices of the European Federation of Societies for Ultrasound in Medicine and Biology EFSUMB assesses the clinically used applications of all forms of elastography, stressing the evidence from meta-analyses and giving practical advice for their uses and interpretation. Diffuse liver disease forms the largest section, reflecting the wide experience with transient and shear wave elastography . Then follow the breast, thyroid, gastro-intestinal tract, endoscopic elastography, the prostate and the musculo-skeletal system using strain and shear wave elastography as appropriate. The document is intended to form a reference and to guide clinical users in a practical way.

Nonalcoholic fatty liver disease and carotid atherosclerosis in children

Nonalcoholic fatty liver disease (NAFLD) is closely associated with several metabolic syndrome features, including obesity, dyslipidemia, insulin resistance, and increased cardiovascular risk. The present study was undertaken to assess whether NAFLD in children is associated with increased carotid artery intima-media thickness (IMT), a marker of early-generalized atherosclerosis. We analyzed carotid IMT along with serum triglycerides, total, low-density lipoprotein and high-density lipoprotein cholesterol, glucose, insulin, insulin resistance index (as homeostasis model assessment of insulin resistance), aminotransferases, leptin, and adiponectin in 29 obese children with NAFLD, 33 obese children without liver involvement, and 30 control children. The diagnosis and severity of NAFLD was based on ultrasound scan, after exclusion of infectious and metabolic disorders. Obese children with NAFLD had significantly increased carotid IMT [mean 0.58 (95% confidence intervals 0.54–0.62 mm)] than obese children without liver involvement [0.49 (0.46–0.52) mm; p = 0.001] and control children [0.40 (0.36–0.43) mm; p < 0.0005]. In a stepwise multiple regression model, after adjusting for age, gender, Tanner stage, and cardiovascular risk factors, the severity of fatty liver was significantly associated with maximum IMT (b = 0.08; p < 0.0005). Our results suggest that NAFLD is strongly associated with carotid atherosclerosis even in childhood.

New ePTFE/FEP-covered stent in the palliative treatment of malignant biliary obstruction

PURPOSE To determine the technical efficacy and safety of an expanded polytetrafluoroethylene and fluorinated ethylene propylene (ePTFE/FEP)-covered metallic stent in the management of malignant biliary obstruction and to evaluate its clinical efficacy by estimating stent patency and patient survival rates. MATERIALS AND METHODS Twenty-six patients with common bile duct stricture caused by malignant disease were treated by placement of 29 stents. The stent consists of an inner ePTFE/FEP lining and an outer supporting structure of nitinol wire. Multiple wire sections elevated from the external surface provide anchoring. Stents are available in two versions, with or without holes in the proximal stent lining. Holes should provide drainage of the cystic duct or biliary side branches when covered by the proximal stent end. Clinical evaluation and assessment of serum bilirubin and liver enzyme levels were done before stent placement and at 1, 3, 6, and 9 months. Average follow-up duration was 5.4 months (range, 5 d to 12.5 mo). RESULTS Placement was successful in all cases. The 30-day mortality rate was 11.5%. The survival rates were 40% and 15% at 6 and 12 months, respectively. Eighty-four percent of patients had adequate palliative drainage during their lifetime. The stent patency rates were 91%, 77%, and 77% at 3, 6, and 12 months, respectively. Four patients (16%) presented with stent occlusion and needed repeat intervention. No migration occurred. Complications other than stent occlusion occurred in five patients (19%); among these, acute cholecystitis was observed in three patients (12%). CONCLUSION Preliminary results suggest that placement of this ePTFE/FEP-covered stent is feasible and effective in achieving biliary drainage. The percentage of patients undergoing lifetime palliation and the midterm patency are promising. However, the incidence of acute cholecystitis is high. Treatment of a larger group of patients is mandatory to validate these long-term results.

Prospective Comparative Analysis of Colour-Doppler Ultrasound, Contrast-enhanced Ultrasound, Computed Tomography and Magnetic Resonance in Detecting Endoleak after Endovascular Abdominal Aortic Aneurysm Repair

OBJECTIVES To assess the accuracy of colour-Doppler ultrasound (CDUS), contrast-enhanced ultrasonography (CEUS), computed tomography angiography (CTA) and magnetic resonance angiography (MRA) in detecting endoleaks after endovascular abdominal aortic aneurysm repair (EVAR). DESIGN Prospective, observational study. MATERIALS AND METHODS From December 2007 to April 2009, 108 consecutive patients who underwent EVAR were evaluated with CDUS, CEUS, CTA and MRA as well as angiography, if further treatment was necessary. Sensitivity, specificity, accuracy and negative predictive value of ultrasound examinations were compared with CTA and MRA as the reference standards, or with angiography when available. RESULTS Twenty-four endoleaks (22%, type II: 22 cases, type III: two cases) were documented. Sensitivity and specificity of CDUS, CEUS, CTA, and MRA were 58% and 93%, 96% and 100%, 83% and 100% and 96% and 100% respectively. CEUS allowed better classification of endoleaks in 10, two and one patients compared with CDUS, CTA and MRA, respectively. CONCLUSIONS The accuracy of CEUS in detecting endoleaks after EVAR is markedly better than CDUS and is similar to CTA and MRA. CEUS seems to be a feasible tool in the long-term surveillance after EVAR, and it may better classify endoleaks missed by other imaging techniques.

Serum uric acid and its association with metabolic syndrome and carotid atherosclerosis in obese children

OBJECTIVE The association between hyperuricemia, metabolic syndrome (MS), and atherosclerotic vascular disease has been reported in adults, but very little is known about this association in children. The aims of our study were to ascertain the correlates of uric acid (UA) in a sample of obese children, and to investigate whether UA is associated with carotid intima-media thickness (IMT) independently from classical risk factors including MS. METHODS We analyzed carotid IMT along with serum triglycerides, total and high-density lipoprotein cholesterol, glucose, insulin, insulin resistance index (as homeostasis model assessment of insulin resistance), alanine aminotransferase, gamma-glutamyltransferase, creatinine, and UA in 120 obese children and 50 healthy control children. RESULTS UA concentrations were significantly higher in obese children compared with controls; moreover, they correlated with the most established cardiovascular risk factors. In the group of obese children, after adjustment for age, sex, pubertal stage, and creatinine, an independent association between UA levels and the presence of MS syndrome was observed (unstandardized coefficient, 0.044 (95% confidence intervals (CI) 0.015-0.072); P<0.01). Carotid IMT significantly increased in the fourth quartile of UA compared with that in the first, second, and third quartile (0.49 (0.46-0.53), 0.53 (0.49-0.56), and 0.55 (0.52-0.59) vs 0.61 (95% CI, 0.58-0.64); P<0.01). When multivariate analysis was performed after adjusting for age, gender, pubertal stage, creatinine, and MS (considered as a single clinical entity), or the individual components of MS simultaneously included, the association between UA and carotid IMT was significant (P<0.01). CONCLUSIONS In obese children and adolescents, increased UA levels are associated with carotid atherosclerosis.

Functional and morphological vascular changes in pediatric nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) has been consistently found to be associated with features of the metabolic syndrome (MS), a condition carrying a high risk of cardiovascular events. The present study aimed to determine whether, in children and adolescents, NAFLD is atherogenic beyond its association with MS and its components. We assessed both flow‐mediated dilation of the brachial artery (FMD) and carotid intima‐media thickness (cIMT), along with lipid profile, glucose, insulin, insulin resistance, and high‐sensitivity C‐reactive protein (CRPHS), in 250 obese children, 100 with and 150 without NAFLD, and 150 healthy normal‐weight children. NAFLD was diagnosed by ultrasound examination and persistently elevated alanine aminotransferase, after exclusion of infectious and metabolic disorders. Compared to controls and children without liver involvement, those with ultrasound‐diagnosed NAFLD (and elevated alanine aminotransferase) demonstrated significantly impaired FMD and increased cIMT. Patients with NAFLD had more features of MS and elevated CRPHS levels. In addition, percent FMD was remarkably reduced, whereas cIMT was increased in obese children with MS compared to those without MS. Using logistic regression analysis, the presence of NAFLD was found to be an independent predictor of low percent FMD (odds ratio, 2.25 [95% confidence interval, 1.29 to 3.92]; P = 0.004) as well as of increased cIMT (1.98 [1.16 to 3.36]; P = 0.031), after adjustment for age, gender, Tanner stage, and presence of MS. When we analyzed the relations between cIMT and measures of FMD in patients with NAFLD, the disease was associated with increased cIMT in children with impaired FMD status. Conclusion: The presence of liver disease entails more severe functional and anatomic changes in the arterial wall. Its detection may help identify individuals with increased cardiometabolic risk. (HEPATOLOGY 2010.)

Acoustic Radiation Force Impulse (ARFI) ultrasound imaging of solid focal liver lesions

OBJECTIVE The aim of this paper was to evaluate the application of ARFI ultrasound imaging and its potential value for characterizing focal solid liver lesions. MATERIALS AND METHODS In this multicentric prospective study, over a total non-consecutive period of four months, all patients underwent ARFI US examination. Two independent operators performed 5 measurements per each lesion and 2 measurements in the surrounding liver. According to the definitive diagnosis, a mean velocity value and standard deviations were obtained in each type of focal solid lesion, compared by using t-test, and the inter-operator evaluation was performed by using the Students t-test. A comparison between the total mean values of each type of lesion and the mean value of the parenchyma was performed. RESULTS 40 lesions were evaluated and a total of 400 measurements were obtained. The lesions were: 6/40(15%) hepatocellular carcinomas, 7/40(17.5%) hemangiomas, 5/40(12.5%) adenomas, 9/40(22.5%) metastases and 13/40(32.5%) focal nodular hyperplasias. The total mean values obtained were: 2.17 m/s in HCCs, 2.30 m/s in hemangiomas, 1.25 m/s in adenomas, 2.87 m/s in metastases and 2.75 m/s in FNHs. The inter-operator evaluation resulted non-statistically different (p>0.05). A significant difference (p<0.05) was always found by comparing adenomas to the other lesions. 160 measurements were obtained in the surrounding parenchyma, with a no significant difference between values measured in adenomas and in the surrounding liver. CONCLUSIONS ARFI technology with Virtual Touch tissue quantification could non-invasively provide significant complementary information regarding the tissue stiffness, useful for the differential diagnosis of focal solid liver lesions.

Prospective evaluation of multiparametric ultrasound and quantitative elastosonography in the differential diagnosis of benign and malignant thyroid nodules: Preliminary experience

PURPOSE To assess the clinical value of quantitative elastosonography compared with multiparametric ultrasound in differentiating the nature of thyroid nodules. METHODS AND MATERIALS Ninety-seven consecutive patients (32 males, 65 females, mean age, 54 years, range 20-81 years) with thyroid nodules previously detected at color-Doppler ultrasound (CDUS), were prospectively examined with elastosonography with dedicated quantitative software (Elasto-Q, Toshiba) before surgery. Ultrasound examination and elastosonography were evaluated by two investigators in consensus. US features, color-Doppler pattern, and strain ratio value were evaluated. Sensitivity and specificity of CDUS and sono-elastography were compared using X(2) test and ROC curves. RESULTS Sensitivity and specificity of hypoechogenicity, irregular margins or suspicious halo features, CDUS blood flow pattern, and strain ratio in the diagnosis of malignant nodules were 56.8%, 62.2%, 54.1% and 97.3% and 71.7%, 93.3%, 28.3%, and 91.7%, respectively. Elastosonography was more sensitive and specific than all ultrasonographic features in predicting malignancy of the thyroid nodules (p<0.0001). According to elastosonographic features the lesions characterized by strain ratio ≥ 2 were highly likely to be of malignant nature (p<0.0001, O.R. 396, 95%, CI: 44-3530). CONCLUSIONS The results of the present study suggest that elastosonography with Q system is a valuable tool in the characterization of thyroid nodules and it seems to be far more accurate than CDUS. These findings as well as those of previous studies support its use in selecting patients who are candidates for surgery.

Does multidetector-row CT eliminate the role of diagnostic laparoscopy in assessing the resectability of pancreatic head adenocarcinoma?

BackgroundWe hypothesized that the high-quality images from multidetector-row computed tomography (MDCT) would lead to improved sensitivity and specificity for predicting resectable pancreatic head adenocarcinoma, thus diminishing the value of staging laparoscopy.MethodsForty four consecutive patients underwent thin-section dual-phase MDCT to stage their tumor, followed by an attempted pancreaticoduodenectomy. Four radiologists who were blinded to the operative outcome reviewed the scans and graded the presence of distant and nodal metastases, as well as the degree of arterial and portal involvement. The radiologic criteria for resectability were no distant metastasis, a patent portal vein, and <50% arterial involvement.ResultsThe overall resectability for this cohort was 52% (23/44). The 21 unresectable cases, included five liver metastases, three peritoneal metastases, and 13 locally invasive tumors. The negative margin resection rate was 34% (15/44). There were no portal vein resections. The sensitivity and specificity of MDCT for predicting resectability were 96% (22/23) and 33% (7/21), respectively. In this cohort, the positive and negative predictive values were 61% (22/36) and 87.5% (7/8), respectively. As determined by univariate logistic regression, only the degree of arterial involvement was a significant predictor of resectability (p = 0.02). As determined by multivariate logistic regression using both arterial and portal involvement, arterial involvement was predictive (p = 0.03) but portal vein involvement was not (p = 0.45).ConclusionsDespite the improvements in image quality obtained with multidetector-row technology, CT imaging remains a relatively nonspecific test for predicting resectability in patients with adenocarcinoma of the head of the pancreas. Minimally invasive modalities with higher specificity, particularly laparoscopy, continue to have an important role in staging pancreatic head adenocarcinoma.