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Simona Bota,
Ioan Sporea,
Markus Peck-Radosavljevic,
Roxana Sirli,
Hironori Tanaka,
Hiroko Iijima,
Hidetsugu Saito,
Hirotoshi Ebinuma, Monica Lupsor,
Radu Badea, [......],
Christoph Sarrazin,
Hirokazu Takahashi,
Naofumi Ono,
Fabio Piscaglia,
Sara Marinelli,
Mirko D'Onofrio,
Anna Gallotti,
Petra Salzl,
Alina Popescu,
Mirela Danila
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ABSTRACT: BACKGROUND: Acoustic Radiation Force Impulse Elastography is a new method for non-invasive evaluation of liver fibrosis. AIM: To evaluate the impact of elevated alanine aminotransferase levels on liver stiffness assessment by Acoustic Radiation Force Impulse Elastography. METHODS: A multicentre retrospective study including 1242 patients with chronic liver disease, who underwent liver biopsy and Acoustic Radiation Force Impulse. Transient Elastography was also performed in 512 patients. RESULTS: The best Acoustic Radiation Force Impulse cut-off for predicting significant fibrosis was 1.29m/s in cases with normal alanine aminotransferase levels and 1.44m/s in patients with alanine aminotransferase levels>5× the upper limit of normal. The best cut-off for predicting liver cirrhosis were 1.59 and 1.75m/s, respectively. Acoustic Radiation Force Impulse cut-off for predicting significant fibrosis and cirrhosis were relatively similar in patients with normal alanine aminotransferase and in those with alanine aminotransferase levels between 1.1 and 5× the upper limit of normal: 1.29m/s vs. 1.36m/s and 1.59m/s vs. 1.57m/s, respectively. For predicting cirrhosis, the Transient Elastography cut-offs were significantly higher in patients with alanine aminotransferase levels between 1.1 and 5× the upper limit of normal compared to those with normal alanine aminotransferase: 12.3kPa vs. 9.1kPa. CONCLUSION: Liver stiffness values assessed by Acoustic Radiation Force Impulse and Transient Elastography are influenced by high aminotransferase levels. Transient Elastography was also influenced by moderately elevated aminotransferase levels.
Digestive and Liver Disease 03/2013; · 3.05 Impact Factor
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Automatic computers applied mathematics. 02/2013; 18(2):239-255.
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ABSTRACT: The objective of this paper is to assess the role of conventional and high-frequency ultrasound in the evaluation of the depth of cutaneous skin cancer. The study was performed on 46 subjects, divided into 3 categories, according to their skin pathology [basal cell carcinoma (BCC), 18 subjects; superficial spreading melanoma (SSM), 8 subjects; nodular melanoma (NM), 20 subjects]. Conventional and high-frequency ultrasonographic measurements were performed in order to assess the thickness of the tumors and the vascularization degree. We compared the mean values of the tumoral thickness obtained by using ultrasound (ultrasonographic depth index) with the histological depth index, obtained after performing histological sections stained with hematoxylin-eosin, and specific monoclonal antibodies in case of pigmented tumors. We established a correlation index between the histological and ultrasonographic values of the tumoral thickness. We found a strong correlation between the ultrasonographic index (measured by high-frequency sonography) and the histological index for nodular BCC (correlation of 98.4 %), NM subjects (correlation of 98.4 %), and SSM subjects (correlation of 99.4 %). An increase of the blood supply was noticed in nodular lesions only. Ultrasonography allows a very accurate assessment of skin cancer. The ultrasonographic depth index can be considered an objective, non-invasive marker for cutaneous tumors, comparable to the histological one, with a very good sensitivity (98-99 %).
Archives for Dermatological Research 02/2013; · 2.28 Impact Factor
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ABSTRACT: Non-invasive methods for the assessment of liver fibrosis are accurate in staging chronic liver diseases before treatment. Aim: To prospectively assess liver fibrosis in chronic hepatitis C (CHC) in patients treated vs untreated, using non-invasive methods.
224 patients with CHC were included in the study: 179 received antiviral treatment for 48 weeks, and 45 patients received no antiviral therapy. All patients underwent liver biopsy at baseline and were also evaluated by simple biological scores (APRI, HAPRI, Forns, Bonacini, Lok) and transient elastography (TE). The progression of fibrosis was non-invasively assessed over a period of 72 weeks.
Fibrosis decreased significantly in patients who gained sustained virological response (SVR). A significant decrease of fibrosis was also observed in all treated patients, irrespective of SVR when using APRI, HAPRI and Bonacini scores (p=0.001, 0.009 and 0.02). Untreated patients yielded constant values of fibrosis or a slight increase in follow-up. Patients with Lok score and stiffness predictive for cirrhosis had a decreasing trend of fibrosis (p=0.03 for Lok and 0.05 for TE), but persisting in the cirrhosis domain. Of the non responders, those who gained biological response demonstrated improvement of fibrosis assessed by APRI and TE.
The prospective follow-up of liver fibrosis assessed by simple biological scores and TE in patients with CHC revealed a downstaging of fibrosis in treated patients and especially in those who gained SVR.
Journal of gastrointestinal and liver diseases: JGLD 12/2012; 21(4):375-82. · 1.81 Impact Factor
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11/2012; , ISBN: 978-953-51-0853-5
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ABSTRACT: High-frequency ultrasound is a noninvasive tool that offers characteristic markers, quantifying the cutaneous changes of the physiological senescence process.
The aim was to assess the changes in skin thickness, dermal density and echogenicity, as part of the ageing process, with different age intervals.
The study was performed on 160 patients, aged 40.4 ± 21.2, divided into four age categories: <20, 21-40, 41-60, 61-80. Ultrasonographic images (Dermascan device) were taken from three sites: dorsal forearm (DF), medial arm (MA), zygomatic area (ZA). We assessed the thickness of epidermis and dermis (mm), number of low, medium, high echogenicity pixels, the ratio between the echogenicity of the upper and lower dermis (LEPs/LEPi), and SLEB (subepidermal low echogenicity band). The statistical analysis was performed using SPSS 15.00. A P value <0.05 was considered significant.
On all examined sites, it was found that the dermal thickness increases in the 21 to 40 year interval (P<0.0001). After the 21 to 40 year interval, the number of low echogenic pixels increases significantly, especially on photoexposed sites. High-echogenic pixels follow the same pattern on all examined sites: they increase in the 21 to 40 year interval and decrease in the 3rd and 4th age category. The LEPs/LEPi ratio increases significantly with age, at all sites (P<0.05), due to an increase of hypoechogenic pixels in the upper dermis.
High-frequency ultrasound is a noninvasive "histological" tool that can assess the cutaneous structure and age-related changes. It offers imagistic markers, comparable to the histological parameters and also characteristic ultrasonographic markers. Histology remains the gold standard for the investigation of the integumentary system.
Indian journal of dermatology, venereology and leprology 07/2012; 78(4):519. · 0.98 Impact Factor
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ABSTRACT: PurposeNoninvasive diagnosis of liver fibrosis is a popular topic in the medical literature. Textural analysis on B-mode ultrasound
is viewed as a noninvasive tool for fibrosis staging. A liver tissue model is proposed and used to simulate ultrasound images.
MethodsOne hundred and twenty-five patients with chronic hepatitis C were included in this study. Patients were investigated using
B-mode ultrasound and liver biopsy (Metavir scoring). A texture analysis tool consisting of 12 algorithms and a logistic regression
classifier was implemented and validated. Tissue model parameters were varied and ultrasound images were generated.
ResultsTexture analysis can discriminate between stages F0 and F4 using actual patient data (accuracy 69.5%) and synthetic images
(accuracy 76.6%). A human expert is less sensitive than texture analysis in discriminating subtle changes in ultrasound images.
High fibrosis detection accuracies are correlated with larger differences in portal space density (r
2=0.5). Accuracies measured when we varied only the fibrosis stage and kept the rest of the tissue parameters constant showed
high detection rates only in a narrow parameter interval.
ConclusionThe texture analysis system shows limited performance in staging fibrosis and it cannot be used for accurate monitoring of
fibrosis evolution over time.
KeywordsTissue model–Fibrosis staging–Noninvasive diagnosis–Texture analysis
Journal of Medical Ultrasonics 04/2012; 38(3):105-117. · 0.33 Impact Factor
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ABSTRACT: The prediction of fibrosis is an essential part of the assessment and management of patients with chronic liver disease. Non-invasive tests (NITs) have a number of advantages over the traditional standard of fibrosis assessment by liver biopsy, including safety, cost-effectiveness, and widespread accessibility.
The aim of this study was to determine the accuracy of certain biomarkers and transient elastography (TE) alone or in combination to predict the stage of liver fibrosis in chronic hepatitis C (CHC). Also, we examined whether the combination of certain biomarkers and TE could increase the diagnostic accuracy of liver fibrosis assessment.
A total of 446 patients who were previously diagnosed with CHC were included in the study. In the study group, 6 blood-based scores (APRI, Forns, Fib-4, Hepascore, FibroTest, and Fibrometer) were calculated, and TE was performed to validate the stage of fibrosis, compared with liver biopsy (LB) as the standard.
Significant fibrosis (F ≥ 2) was predicted with an AUROC of 0.727, 0.680, 0.714, 0.778, 0.688, 0.797, and 0.751 for the APRI, Forns, Fib-4, FibroTest, Hepascore, and Fibrometer scores and TE (Fibroscan), respectively. Severe fibrosis (F ≥ 3) was predicted, with AUROCs ranging between 0.705 and 0.811 for Hepascore and Fibrometer, respectively. Of the biomarkers, Fibrometer had the highest AUROC value in predicting both significant and severe fibrosis. The combination of APRI or FIB-4 with Fibrometer increased the diagnostic accuracy for significant fibrosis (from 69.07 to 82.27 for APRI, P = 0.001 and from 57.74 to 81.33, P = 0.001 for Fib-4). Combining APRI or Fib-4 with TE also increased the diagnostic accuracy (from 69.07 to 80.70%, P = 0.001 for APRI and from 57.74 to 81.33%, P = 0.001 for Fib-4) for significant fibrosis. The association that included Fibrotest was also reliable for the improvement of diagnostic accuracy. These combinations were more accurate or the assessment of severe fibrosis.
The synchronous association between a simple, inexpensive score and a complex but expensive score or TE increases the diagnostic accuracy of non-invasive methods for the assessment of liver fibrosis stage.
Hepatitis Monthly 03/2012; 12(3):177-84. · 2.19 Impact Factor
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Comp. Math. Methods in Medicine. 01/2012; 2012.
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Comp. Math. Methods in Medicine. 01/2012; 2012.
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ABSTRACT: Texture analysis is viewed as a method to enhance the diagnosis power of classical B-mode ultrasound image. The present paper aims to evaluate and eliminate the dependence between the human expert and the performance of such a texture analysis system in predicting the cirrhosis in chronic hepatitis C patients. 125 consecutive chronic hepatitis C patients were included in this study. Ultrasound images were acquired from each patient and four human experts established regions of interest. Textural analysis tool was evaluated. The performance of this approach depends highly on the human expert that establishes the regions of interest (P < 0.05). The novel algorithm that automatically establishes regions of interest can be compared with a trained radiologist. In classical form met in the literature, the noninvasive diagnosis through texture analysis has limited utility in clinical practice. The automatic ROI establishment tool is very useful in eliminating the expert-dependent variability.
Computational and Mathematical Methods in Medicine 01/2012; 2012:346713. · 0.68 Impact Factor
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ABSTRACT: Ultrasonography allows the quantification of dermal density and echogenicity changes during the physiological senescence process. Some active ingredients are able to slow down the tissular degeneration and disorganization process. The purpose of this study was to assess the cutaneous changes induced by the topical use of products containing Viniferol(®) as active ingredient, using high-frequency ultrasound. The study was performed over 12 weeks and included 80 healthy Caucasian female subjects, aged 22-75 years, divided into two groups: the study group and the control group. The product was applied according to a predetermined protocol. The measurements performed for each subject were: the thickness of the epidermis and dermis (mm), the number of low, medium, and high echogenic pixels, and the number of low echogenic pixels in the upper dermis/number of low echogenic pixels in the lower dermis. All the parameters showed a significant improvement. Ultrasound measurements showed an increase of the mean thickness of the epidermis (P < 0.0001) and dermis (P < 0.0001) following the application of the Viniferol product as compared to the control group. The changes in the dermal echogenicity confirm the efficacy and direct action of Viniferol upon the cutaneous fibroblasts. No side effects related to the treatment were recorded. The study proves the efficacy of this active ingredient in the cutaneous senescence process as well, as the fact that anti-aging prophylaxis should be initiated in the 20-40 year critical age group. This interval involves specific changes in dermal echogenicity that quantify intense molecular, biochemical and structural changes, being thus mostly and highly responsive to the anti-aging therapy.
Clinical, Cosmetic and Investigational Dermatology 01/2012; 5:7-13.
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ABSTRACT: The noninvasive diagnosis of the malignant tumors is an important issue in research nowadays. Our purpose is to elaborate computerized, texture-based methods for performing computer-aided characterization and automatic diagnosis of these tumors, using only the information from ultrasound images. In this paper, we considered some of the most frequent abdominal malignant tumors: the hepatocellular carcinoma and the colonic tumors. We compared these structures with the benign tumors and with other visually similar diseases. Besides the textural features that proved in our previous research to be useful in the characterization and recognition of the malignant tumors, we improved our method by using the grey level cooccurrence matrix and the edge orientation cooccurrence matrix of superior order. As resulted from our experiments, the new textural features increased the malignant tumor classification performance, also revealing visual and physical properties of these structures that emphasized the complex, chaotic structure of the corresponding tissue.
Computational and Mathematical Methods in Medicine 01/2012; 2012:348135. · 0.68 Impact Factor
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Monica Lupsor
Medical ultrasonography 09/2011; 13(3):183-4.
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ABSTRACT: In chronic liver diseases, a correct estimation of the severity of liver fibrosis is important for recommendations regarding the treatment. Nowadays, evaluation of fibrosis is done by noninvasive methods such as biochemical scores and transient elastography instead of liver biopsy. The lack of sensitivity to detect fibrosis, because of its heterogeneity is a drawback of liver biopsy (LB).
To compare transient elastography (TE) and acoustic radiation force impulse (ARFI) for the evaluation of liver stiffness (LS), against percutaneous LB.
Our study comprised of 223 subjects; 52 without fibrosis (38 volunteers and 14 patients with F0 on LB), 36 with F1, 40 with F2, 26 with F3 and 69 with liver cirrhosis (46 with LB and 23 with signs of cirrhosis). For each patient we performed in the same session 10 TE and 5 ARFI measurements. The median values were calculated.
A strong linear correlation (Spearman rho = 0.870) was found between TE and fibrosis (P < 0.0001); there was also a weaker correlation between ARFI and fibrosis (Spearman rho = 0.646; P < 0.0001). TE measurements were also correlated with ARFI measurements (Spearman rho = 0.733, P < 0.0001). The best test for predicting significant fibrosis (F ≥ 2) was TE with a cut-off value of 7.1 kPa (AUROC 0.953). For ARFI, the cut-off value was 1.27 m/s-area under ROC curve (AUROC): 0.890, sensitivity (Se) of 88.7%, specificity (Sp) of 67.5%, positive predictive value (PPV) of 64.5%, and negative predictive value (NPV) of 90% (P = 0.0044). For predicting cirrhosis (F = 4), the optimum cut-off values were 14.4 kPa for TE (AUROC: 0.985, Se: 95.6%, Sp: 94.7%, PPV: 89.2%, NPV: 98%) and 1.7 m/s for ARFI (AUROC: 0.931, Se: 93%, Sp: 86.7%, PPV: 73.6%, NPV: 96.9%) (P = 0.0102).
LS evaluation by means of ARFI is not superior to TE for the assessment of liver fibrosis. ARFI is an accurate test for the diagnosis of cirrhosis.
Hepatitis Monthly 07/2011; 11(7):532-8. · 2.19 Impact Factor
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ABSTRACT: This paper presents an automatic tool capable to learn from a patients data set with 24 medical indicators characterizing each sample and to subsequently use the acquired knowledge to differentiate between five degrees of liver fibrosis. The indicators represent clinical observations and the liver stiffness provided by the new, non-invasive procedure of Fibroscan. The proposed technique combines a hill climbing algorithm that selects subsets of important attributes for an accurate classification and a core represented by a cooperative coevolutionary classifier that builds rules for establishing the diagnosis for every new patient. The results of the novel method proved to be superior as compared to the ones obtained by other important classification techniques from the literature. Additionally, the proposed methodology extracts a set of the most meaningful attributes from the available ones.
Computers in biology and medicine 03/2011; 41(4):238-46. · 1.27 Impact Factor
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ABSTRACT: Noninvasive serum liver fibrosis markers and liver stiffness could be used as predictors of esophageal varices in cirrhotic patients because portal hypertension is related to liver fibrosis. The aim of this study was to compare the performance of common serum fibrosis scores and transient elastography in diagnosing esophageal varices and to propose a new algorithm for predicting large varices.
231 consecutive cirrhotic patients (58.4% males, mean age 55.9 years) were enrolled. Routine biological tests were performed, so that APRI, FIB-4, Forns Index and Lok Score could be calculated. All patients underwent transient elastography and eso-gastroscopy. The diagnostic performance of the methods was assessed using sensitivity, specificity, positive predictive value, negative predictive value, accuracy, likelihood ratios and receiver operating characteristic curves.
The Lok Score was the best among all the serum scores for diagnosing the varices. For a value higher than 0.8, it had a 45.5% positive predictive value, 86.4% negative predictive value and 67.72% diagnostic accuracy for prediction of large varices. For liver stiffness higher than 30.8KPa, the positive predictive value was 47.3%, negative predictive value 81% and diagnostic accuracy 68.32%. Using both tests simultaneously, the presence of large varices was predicted with a diagnostic accuracy of 78.12%, obtaining an increment in NPV and -LR up to 93.67% and 0.21, respectively.
The Lok Score is a good predictor for excluding the presence of large varices in cirrhotic patients, similarly with liver stiffness. The two methods can be successfully combined into a noninvasive algorithm for the assessment of esophageal varices in cirrhotic patients.
Journal of gastrointestinal and liver diseases: JGLD 03/2011; 20(1):57-64. · 1.81 Impact Factor
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ABSTRACT: Hepatic fibrosis, the principal pointer to the development of a liver disease within chronic hepatitis C, can be measured through several stages. The correct evaluation of its degree, based on recent different non-invasive procedures, is of current major concern. The latest methodology for assessing it is the Fibroscan and the effect of its employment is impressive. However, the complex interaction between its stiffness indicator and the other biochemical and clinical examinations towards a respective degree of liver fibrosis is hard to be manually discovered. In this respect, the novel, well-performing evolutionary-powered support vector machines are proposed towards an automated learning of the relationship between medical attributes and fibrosis levels. The traditional support vector machines have been an often choice for addressing hepatic fibrosis, while the evolutionary option has been validated on many real-world tasks and proven flexibility and good performance.
The evolutionary approach is simple and direct, resulting from the hybridization of the learning component within support vector machines and the optimization engine of evolutionary algorithms. It discovers the optimal coefficients of surfaces that separate instances of distinct classes. Apart from a detached manner of establishing the fibrosis degree for new cases, a resulting formula also offers insight upon the correspondence between the medical factors and the respective outcome. What is more, a feature selection genetic algorithm can be further embedded into the method structure, in order to dynamically concentrate search only on the most relevant attributes. The data set refers 722 patients with chronic hepatitis C infection and 24 indicators. The five possible degrees of fibrosis range from F0 (no fibrosis) to F4 (cirrhosis).
Since the standard support vector machines are among the most frequently used methods in recent artificial intelligence studies for hepatic fibrosis staging, the evolutionary method is viewed in comparison to the traditional one. The multifaceted discrimination into all five degrees of fibrosis and the slightly less difficult common separation into solely three related stages are both investigated. The resulting performance proves the superiority over the standard support vector classification and the attained formula is helpful in providing an immediate calculation of the liver stage for new cases, while establishing the presence/absence and comprehending the weight of each medical factor with respect to a certain fibrosis level.
The use of the evolutionary technique for fibrosis degree prediction triggers simplicity and offers a direct expression of the influence of dynamically selected indicators on the corresponding stage. Perhaps most importantly, it significantly surpasses the classical support vector machines, which are both widely used and technically sound. All these therefore confirm the promise of the new methodology towards a dependable support within the medical decision-making.
Artificial intelligence in medicine 01/2011; 51(1):53-65. · 1.65 Impact Factor
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ABSTRACT: Splenomegaly in a common finding in liver cirrhosis that should determine changes in the spleen's density because of portal and splenic congestion and/or because of tissue hyperplasia and fibrosis. These changes might be quantified by elastography, so the aim of the study was to investigate whether spleen stiffness measured by transient elastography varies as liver disease progresses and whether this would be a suitable method for the noninvasive evaluation of the presence of esophageal varices.
One hundred and ninety-one patients (135 liver cirrhosis, 39 chronic hepatitis and 17 healthy controls) were evaluated by transient elastography for measurements of spleen and liver stiffness. Cirrhotic patients also underwent upper endoscopy for the diagnosis of esophageal varices.
Spleen stiffness showed higher values in liver cirrhosis patients as compared with chronic hepatitis and with controls: 60.96 vs 34.49 vs 22.01 KPa (P<0.0001). In the case of liver cirrhosis, spleen stiffness was significantly higher in patients with varices as compared with those without (63.69 vs 47.78 KPa, P<0.0001), 52.5 KPa being the best cut-off value, with an area under the receiver operating characteristic of 0.74. Using both liver and spleen stiffness measurement we correctly predicted the presence of esophageal varices with 89.95% diagnostic accuracy.
Spleen stiffness can be assessed using transient elastography, its value increasing as the liver disease progresses. In liver cirrhosis patients spleen stiffness can predict the presence, but not the grade of esophageal varices. Esophageal varices' presence can be better predicted if both spleen and liver stiffness measurements are used.
Journal of Gastroenterology and Hepatology 01/2011; 26(1):164-70. · 2.87 Impact Factor
