Detection Of Diffuse Liver Disease Research Articles

Multiparametric MRI for early detection of diffuse liver disease: an interview with David Breen.

David J Breen is Associate Professor of Radiology and previous Clinical Director of Radiology at University Hospital Southampton. His interests are in abdominal imaging and intervention, particularly of hepato-pancreato-biliary (HPB)and renal disease. He has a major interest in image-guided tumor ablation and improving outcomes from these procedures. He has previously served as Vice Chair of the NHS England Clinical Reference Group in Interventional Radiology and for the NIHR/NCRN Upper GI Clinical Studies Group.

Hepatic MR imaging for in vivo differentiation of steatosis, iron deposition and combined storage disorder: Single-ratio in/opposed phase analysis vs. dual-ratio Dixon discrimination

To assess whether in vivo dual-ratio Dixon discrimination can improve detection of diffuse liver disease, specifically steatosis, iron deposition and combined disease over traditional single-ratio in/opposed phase analysis. Seventy-one patients with biopsy-proven (17.7 ± 17.0 days) hepatic steatosis (n = 16), iron deposition (n = 11), combined deposition (n = 3) and neither disease (n = 41) underwent MR examinations. Dual-echo in/opposed-phase MR with Dixon water/fat reconstructions were acquired. Analysis consisted of: (a) single-ratio hepatic region-of-interest (ROI)-based assessment of in/opposed ratios; (b) dual-ratio hepatic ROI assessment of in/opposed and fat/water ratios; (c) computer-aided dual-ratio assessment evaluating all hepatic voxels. Disease-specific thresholds were determined; statistical analyses assessed disease-dependent voxel ratios, based on single-ratio (a) and dual-ratio (b and c) techniques. Single-ratio discrimination succeeded in identifying iron deposition (I/O(Ironthreshold)<0.88) and steatosis (I/O(Fatthreshold>1.15)) from normal parenchyma, sensitivity 70.0%; it failed to detect combined disease. Dual-ratio discrimination succeeded in identifying abnormal hepatic parenchyma (F/W(Normalthreshold)>0.05), sensitivity 96.7%; logarithmic functions for iron deposition (I/O(Irondiscriminator)<e((0.01-F/W(Iron))/0.48)) and for steatosis (I/O(Fatdiscriminator)>e((F/W(Fat)-0.01)/0.48)) differentiated combined from isolated diseases, sensitivity 100.0%; computer-aided dual-ratio analysis was comparably sensitive but less specific, 90.2% vs. 97.6%. MR two-point-Dixon imaging using dual-ratio post-processing based on in/opposed and fat/water ratios improved in vivo detection of hepatic steatosis, iron deposition, and combined storage disease beyond traditional in/opposed analysis.

The Role of EUS Elastography in the Diagnosis of Focal Liver Lesions

Sonoelastography is a new ultrasound procedure for the assessment of tissue elasticity, with a very good potential of implementation in the field of endoscopic ultrasogography. The reconstruction of tissue elasticity provides important information about the nature of the disease. The elasticity of the tissue is evaluated qualitatively on the standard B mode with color image in the range from red to blue. The more hard tissues are presenting in blue and easily compressible tissues in red. Giovannini suggest that EUS elastography could be a good diagnostic tool in defining the tissue characteristics of benign and malignant lesions. Case Report: 25-year-old woman presented at our Unit with a two-month history of fever of unknown origin, night sweats and mild abdominal pain. Her previous medical history was unremarkable. On physical examination, only abnormal finding was enlarged liver palpable 3 cm below the right costal margin. Laboratory results showed slightly elevated liver enzymes. Synthetic liver function was normal. Excluded were all potential bacterial and virological causes, hereditary and acquired metabolic liver diseases and autoimmune liver diseases. Chest X-ray was normal. Abdominal ultrasound (US) detected several hipoechogenic lesions, two in left liver lobe (26 and 29 mm) and several smaller in right liver lobe (up to 8 mm in size). This was confirmed with contrast-enhanced multislice computed tomography (MSCT) which showed multiple hypoattenuated lesions on native images which were hypovascular on postcontrast images with no signs of abnormal intrahepatic vascularisation EUS elastography showed diffuse “blue” pattern in the left liver lobe, indicating hard elasticity in the area of focal lessions and in the surrounding tissue. It was therefore concluded that we were dealing with a diffuse liver disease. Liver biopsy of the left liver lobe was performed with US guidance. Tissue cylinder contained the tissue surrounding the focal lesion and part of the focal lesion itself. Histological analysis revealed diffuse granulomatosus infiltration of the liver. Differential diagnosis of hepatic granulomatous disease is very broad, two major causes being sarcoidosis and tuberculosis. . EUS elastography, histology and slightly elevated serum angiotensin converting enzyme (ACE) of 62 U/L (normal up to 52 U/L) pointed toward the diagnosis of liver sarcoidosis. We suggest that EUS elastography is a promising diagnostic method that allows differentiation of the focal liver lesions from the normal liver tissue and detection of diffuse liver disease, with a great diagnostic potential in difficult cases like the one described.

Ultrasound attenuation and backscatter in the liver during prednisone administration

Ultrasound attenuation and backscatter changes resulting from glucocorticoid administration were investigated in a dog model. Ten beagle dogs were randomized into two groups: five were given 2 mg/kg/day IM injections of prednisone to induce steroid hepatopathy and five served as controls. Histology showed vacuolization in most hepatocytes of treated animals on the third day of treatment, and larger, midzonally distributed vacuoles from day 7 on. An increase in both ultrasonic attenuation and backscatter was observed in treated dogs during in vivo measurements. Pooled data from the two groups suggest that attenuation elevations precede backscatter changes. Attenuation was significantly higher in the treated animals than in the controls by day 7. Both attenuation and backscatter were significantly higher in livers of treated than untreated dogs when measured by direct application of the transducer on the liver following euthanasia. We conclude that attenuation and backscatter coefficients can detect early changes in the liver associated with steroid hepatopathy. This may be a useful model to investigate detection of diffuse liver disease with ultrasound tissue characterization.

In vivo quantitative ultrasound imaging and scatter assessments

Instrument independent measurements of ultrasound scattering and attenuation provide useful diagnostic information not available with conventional ultrasound imaging. This dissertation is a continuing effort to test the above hypothesis and to incorporate quantitative ultrasound methods into clinical examinations for early detection of diffuse liver disease. A method for producing quantitative backscatterimages was developed and verified in phantoms. The method involves digitized rf echo signals from a clinical scanner and depth‐dependent ratios of echo data from tissue to echo data from a reference phantom to eliminate instrumentation dependencies and compute attenuation coefficients in the tissue. Quantitative backscatterimages are constructed by com‐ pensating echo data for the computed tissueattenuation. A new technique was developed to compensate for additional attenuation losses through the overlying layers. The method was applied to 35 healthy subjects and 16 patients with diffuse liver disease. Both the attenuation coefficient and the backscatter coefficient exhibited strong discriminating power (p<0.001) for differentiating healthy from fatty livers. Statistically significant differences in the backscatter coefficient (p<0.01) were observed between normal and cirrhotic livers but not in the atttenuation coefficient. An in vivoanimal model of steroid hepatopathy was used to investigate the system sensitivity in detecting early changes in canine liver resulting from corticosteroid administration. The average attenuation coefficient slope increased from 0.7 dB/cm/MHz in controls to 0.82 dB/cm/MHz (at 6 MHz) in treated animals on day 14 into the treatment, and the backscatter coefficient was 2.6E‐3/cm‐sr in controls compared with 7.4E‐3/cm‐sr (at 6 MHz) in treated animals. A simplified quantitative approach using video image signals was developed and provided equally sensitive results to the changes in the liver in this animal model. [For copies contact University Microfilms, Inc., Ann Arbor, Michigan.]

Transient splenic inhomogeneity with contrast-enhanced CT: mechanism and effect of liver disease.

To use computed tomography (CT) and functional imaging to characterize the physiologic processes that result in transient splenic inhomogeneity during contrast material enhancement and determine their value in detection of diffuse liver disease. CT scan data from nine control patients and 13 patients with diffuse liver disease were used to create functional images that displayed splenic perfusion and time to peak enhancement. A pixel-by-pixel analysis was used to create these images. Areas of early enhancement demonstrated higher perfusion and vice versa. In patients with liver disease, splenic perfusion values fell from 1.44 to 1.22 mL/min/mL in the areas that showed early enhancement and 1.24 to 0.89 mL/min/mL in the areas that showed late enhancement. As splenic perfusion values fell, the size of the regions that showed late enhancement increased. The combination of functional images and CT data has clarified the mechanism by which transient splenic inhomogeneity occurs and is of potential value in the detection of diffuse liver disease.

Detection and differentiation of diffuse liver disease by quantitative echography. A retrospective assessment.

The detectability of diffuse liver diseases by quantitative echography was retrospectively investigated using scans of patients with known pathologic findings (n = 103) and of normal subjects (n = 129). The authors determined the best set of quantitative parameters for this task. Quantitative echography was comprised of acoustospectrographic parameters (frequency dependence of attenuation and backscattering) and image texture parameters. The disease processes studied included: acute hepatitis, hepatitis/cirrhosis, alcoholic hepatitis/cirrhosis, primary biliary cirrhosis, and steatosis. Correct differentiation of these diseases ranged from 88% to 97%. Correlations between histologic grading and echographic parameters were poor. With only one exception, the differentiation between any two of the diseases could be made in 60% to 99% of cases. Different parameters better differentiated abnormal from normal scans than among diseases. The detection of diffuse liver diseases can be based on echographic parameters, related to a diffuse scattering model, whereas the differentiation among diseases needs additional parameters derived from a structural scattering model. Further studies are indicated to assess the prospective potential of the devised methods.

Detection of diffuse liver disease by quantitative echography: Dependence on A priori choice of parameters

Quantitative acoustic parameters and image texture parameters were used in a linear discriminant analysis. This analysis was applied to detect retrospectively the classes of diffuse liver disease against a population of normal livers. Three different sets of parameters were employed. The first set was selected by the authors, and the other two were taken from the literature. The area under the Receiver Operating Characteristic (ROC) (or percentage correct classification) obtained with the first set ranged from 88% to 97%, depending on the disease class. It is concluded that the first-order statistical parameters of the image texture (diffuse scattering model) together with the slope of the attenuation coefficient are the most important parameters. As an alternative to the texture parameters, the backscattering parameters (second set of parameters) also yielded a comparably high score. The texture analysis involving structural scattering (third set of parameters) produced a lower percentage of correct classification. The overall conclusion is that the methods devised might be used for prospective diagnosis.

Detection of diffuse liver disease by quantitative echography

Detection of diffuse liver disease by quantitative echography

Supervised Pattern Recognition Techniques in Quantitative Diagnostic Ultrasound

The methods of statistical pattern recognition are well suited to the problems of in vivo ultrasonic tissue characterization. This paper describes supervised pattern recognition methods for selecting features for tissue classification, calculating decision boundaries within the selected feature space, and evaluating the performance. We address the considerations of dimensionality and feature size which are important in classification problems where the underlying probability distributions are not completely known. Examples are given for the detection of diffuse liver disease in the clinical environment.

Ultrasonic detection of diffuse liver disease: A retrospective clinical study: B.J. Oosterveld, J.M. Thijssen, P.C. Hartman and G.J.E. Rosenbusch, Departments of Ophthalmology and Radiology, St. Radboudhospital, University of Nijmegen, Nijmegen, The Netherlands

Ultrasonic detection of diffuse liver disease: A retrospective clinical study: B.J. Oosterveld, J.M. Thijssen, P.C. Hartman and G.J.E. Rosenbusch, Departments of Ophthalmology and Radiology, St. Radboudhospital, University of Nijmegen, Nijmegen, The Netherlands

Discriminant analysis of ultrasonic texture data in diffuse alcoholic liver disease: 1. Fatty liver and cirrhosis

In previous work by our group, it has been shown that the use of texture analysis on digitally recorded radio-frequency ultrasonic signals can provide useful diagnostic information in diffuse liver disease. A rigorous multivariate analysis and the addition of new texture parameters has confirmed the efficacy of the technique. Discriminant functions have been produced to provide excellent accuracies in the detection of diffuse liver disease.