Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0015695 (fatty liver)
 13,941 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Radiology has gained importance in the non-invasive diagnosis of hepatic steatosis. Ultrasonography is usually the first imaging modality for the evaluation of hepatic steatosis. Unenhanced CT with or without dual kVp measurement and MRI with in and out of phase sequence can allow objective evaluation of hepatic steatosis. However, none of the imaging modalities can differentiate non-alcoholic steatohepatitis/fatty liver disease from simple steatosis. Evaluation of hepatic steatosis is important in donor evaluation before orthotopic liver transplantation and hepatic surgery. Recently, one-stop shop evaluation of potential liver donors has become possible by CT and MRI integrating vascular, parenchymal, volume and steatosis evaluation. Moreover hepatic steatosis (diffuse, multinodular, focal, subcortical, perilesional, intralesional, periportal and perivenular), hypersteatosis and sparing (geographic, nodular and perilesional or peritumoral) can cause diagnostic problems as a pseudotumor particularly in the evaluation of oncology patients. Liver MRI is used as a problem-solving tool in these patients. In this review, we discuss the current role of radiology in diagnosing, quantifying hepatic steatosis and solutions for diagnostic problems associated with fatty infiltration and sparing.
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PMID:Imaging of hepatic steatosis and fatty sparing. 1711 3

During the last decade, the role of radiologic modalities in management of patients who have fatty liver disease has expanded. Ultrasonography has been used as a noninvasive alternative to biopsy for monitoring patients who have hepatic steatosis, but MRI is more appealing than ultrasonography to denote minor changes in hepatic fat content. Distinguishing patients who have non-alcoholic steatohepatitis from steatosis alone has become of clinical importance; however, the differences are not apparent with any radiologic modalities. Several modalities have been developed to noninvasively and accurately quantify hepatic fat content and diagnose steatohepatitis. In the future, radiologic modalities might be used to monitor the natural history of the disease or evaluate therapeutic interventions in patients who have non-alcoholic fatty liver disease.
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PMID:Role of radiologic modalities in the management of non-alcoholic steatohepatitis. 1754 71

Quantification of hepatic steatosis is a significant unmet need for the diagnosis and treatment of patients with nonalcoholic fatty liver disease (NAFLD). MRI is capable of separating water and fat signals in order to quantify fatty infiltration of the liver (hepatic steatosis). Unfortunately, fat signal has confounding T(1) effects and the nonzero mean noise in low signal-to-noise ratio (SNR) magnitude images can lead to incorrect estimation of the true lipid percentage. In this study, the effects of bias from T(1) effects and image noise were investigated. An oil/water phantom with volume fat-fractions ranging linearly from 0% to 100% was designed and validated using a spoiled gradient echo (SPGR) sequence in combination with a chemical-shift based fat-water separation method known as iterative decomposition of water and fat with echo asymmetry and least squares estimation (IDEAL). We demonstrated two approaches to reduce the effects of T(1): small flip angle (flip angle) and dual flip angle methods. Both methods were shown to effectively minimize deviation of the measured fat-fraction from its true value. We also demonstrated two methods to reduce noise bias: magnitude discrimination and phase-constrained reconstruction. Both methods were shown to reduce this noise bias effectively from 15% to less than 1%.
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PMID:Fat quantification with IDEAL gradient echo imaging: correction of bias from T(1) and noise. 1765 78

Persons heterozygous for Z, S and rare alpha-1-antitrypsin (AAT, SERPIN1A) polymorphisms (ca. 9% of population) are often considered 'silent' carriers with increased vulnerability to environmentally modulated liver and lung disease. They may have significantly more anxiety and bipolar spectrum disorders, nutritional compromise, and white matter disease [Schmechel DE, Browndyke J, Ghio A. Strategies for the dissection of genetic-environmental interactions in neurodegenerative disorders. Neurotoxicology 2006;27:637-57]. Given association of art and mood disorders, we examined occupation and artistic vocation from this same series. One thousand five hundred and thirty-seven consecutive persons aged 16-90 years old received comprehensive work-up including testing for AAT 'phenotype' and level, nutritional factors, and inflammatory, iron and copper indices. Occupations were grouped by Bureau of Labor Standards classification and information gathered on artistic activities. Proportion of reactive airway disease, obstructive pulmonary disease, and pre-existing anxiety disorder or bipolar disorder were significantly increased in persons carrying AAT non-M polymorphisms compared to normal MM genotype (respectively, 10, 20, 21, and 33% compared to 8, 12, 11, and 9%; contingency table, pulmonary: chi2 37, p=0.0001; affective disorder: chi2=171, p=0.0001). In persons with artistic avocation (n=189) or occupation (n=57), AAT non-M polymorphisms are significantly increased (respectively, proportions of 44 and 40% compared to background rate of 9%; contingency table, avocation: chi2=172, p=0.0001; occupation: chi2=57, p=0.0007). Artistic ability and 'anxiety/bipolar spectrum' mood disorders may represent phenotypic attributes that had selective advantage during recent human evolution, an 'intensive creative energy' (ICE) behavioral phenotype. Background proportion of ICE of 7% consists of 49 of 1312 persons with AAT MM genotype (4%), and 58 of 225 persons with non-MM genotypes (26%) (contingency table, chi2=222, p=0.0001). Penetrance of ICE increases in genotypes with lower AAT levels: PiMS, 18%; PiMZ, 44%; PiSS and PiZZ, 100% (five cases). At all ages, persons with non-MM genotype had significantly higher proportion of thiamine deficiency (50% in PiMZ), reactive hypoglycemia (20% in PiMZ), and possibly fatty liver (thiamine: chi2=28, p=0.0001; hypoglycemia: chi2=92, p=0.0001). In older persons, PiMZ genotype had significantly increased proportion (46%) of brain MRI T2 white matter abnormalities (chi2=49, p=0.003). Persons with ICE and MM genotype showed increased prevalence of pulmonary disorders and same signature as S and Z carriers and homozygotes (see above). Z polymorphism was associated with delayed age of onset (average 7 years) for persons with toxic environmental or occupational exposures (log rank, p=0.0001) and more stable cognitive change in persons with neurodegenerative illness (p<0.05). At all ages, ICE phenotype and Z polymorphism were associated with altered copper homeostasis with low or absent non-ceruloplasmin bound copper (p<0.05). AAT polymorphisms which affect iron, lipid and copper metabolism may affect early events in nervous system development, function and response to environmental exposures. AAT may also be a 'switch' for copper metabolism and low 'free' copper would be theorized to provide protection for lipid oxidation and favorably affect beta-amyloid and other aggregation, but possibly alter early 'critical' period of CNS development. AAT polymorphisms may define an important and treatable subset of persons presenting with CNS disorders. This new proposed phenotype for AAT transcends classic pattern of strictly liver and lung disease, and should be considered for proper evaluation and management of patients presenting with classic AAT-related disorders, affective disorders, persons with ICE, white matter disease or multisystem disorders of memory.
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PMID:Art, alpha-1-antitrypsin polymorphisms and intense creative energy: blessing or curse? 1765 42

We report a case of focal spared area of segment VIII in fatty liver. The patient was a 73-year-old man. Abdominal ultrasonography showed focal hypo-echogenicity with an irregular margin in segment VIII. Abdominal computed tomography and enhanced computed tomography showed a high-density mass in segment VIII of the right lobe. MRI examination revealed that the mass in S8 was high-intense on the T1 out of phase image and iso-intense on the T1 in phase image. The lesion was not observed on T2 weight images. He had a sigmoid colon cancer and was performed a sigmoidectomy and partial resection of the liver. A microscopic examination of the liver specimen revealed normal hepatic parenchymal cells, while the surrounding liver had a fat deposition.
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PMID:[A case of focal spared area of segment VIII in the liver]. 1825 May 97

Hepatic fat fraction (HFF) was measured in 28 lean/obese humans by single-voxel proton spectroscopy (MRS), a two-point Dixon (2PD), and a three-point iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) method (3PI). For the lean, obese, and total subject groups, the range of HFF measured by MRS was 0.3-3.5% (1.1 +/- 1.4%), 0.3-41.5% (11.7 +/- 12.1), and 0.3-41.5% (10.1 +/- 11.6%), respectively. For the same groups, the HFF measured by 2PD was -6.3-2.2% (-2.0 +/- 3.7%), -2.4-42.9% (12.9 +/- 13.8%), and -6.3-42.9% (10.5 +/- 13.7%), respectively, and for 3PI they were 7.9-12.8% (10.1 +/- 2.0%), 11.1-49.3% (22.0 +/- 12.2%), and 7.9-49.3% (20.0 +/- 11.8%), respectively. The HFF measured by MRS was highly correlated with those measured by 2PD (r = 0.954, P < 0.001) and 3PI (r = 0.973, P < 0.001). With the MRS data as a reference, the percentages of correct differentiation between normal and fatty liver with the MRI methods ranged from 68-93% for 2PD and 64-89% for 3PI. Our study demonstrates that the apparent HFF measured by the MRI methods can significantly vary depending on the choice of water-fat separation methods and sequences. Such variability may limit the clinical application of the MRI methods, particularly when a diagnosis of early fatty liver needs to be performed. Therefore, protocol-specific establishment of cutoffs for liver fat content may be necessary.
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PMID:Comparative MR study of hepatic fat quantification using single-voxel proton spectroscopy, two-point dixon and three-point IDEAL. 1830 4

Chemotherapy changes the appearance of liver tumours and may also affect the liver parenchyma. Tumours respond with changes in size, outline, and internal architecture. The accuracy of liver CT for detecting metastases is reduced after chemotherapy. Histologic studies have shown that some metastases which become invisible on follow-up CT are completely sterile at later resection, but most 'disappearing' lesions still contain active tumour. Hepatic steatosis becomes much more common after chemotherapy. Diffuse fatty change may conceal metastases on US and CT, whilst focal steatosis may mimic tumour. Chemical-shift MRI will distinguish fat from tumour. Fatty change is usually reversible, unless the liver receives a 'second hit' of damage from other causes. Sinusoidal obstructive syndrome (SOS), nodular regenerative hyperplasia, veno-occlusive disease and peliosis are manifestations of microvascular injury which can result from chemotherapy. SOS, the most common of these, is undetectable on US and CT, but can be shown on SPIO-enhanced MRI. Although SOS causes no symptoms in most patients, it may cause increased bleeding from the friable liver at surgery, and greater risk of peri-operative adverse events. Rarer complications of chemotherapy include pseudo-cirrhosis and sclerosing cholangitis.
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PMID:The effects of cancer chemotherapy on liver imaging. 1923 92

Noninvasive biomarkers of intracellular accumulation of fat within the liver (hepatic steatosis) are urgently needed for detection and quantitative grading of nonalcoholic fatty liver disease, the most common cause of chronic liver disease in the United States. Accurate quantification of fat with MRI is challenging due the presence of several confounding factors, including T*(2) decay. The specific purpose of this work is to quantify the impact of T*(2) decay and develop a multiexponential T*(2) correction method for improved accuracy of fat quantification, relaxing assumptions made by previous T*(2) correction methods. A modified Gauss-Newton algorithm is used to estimate the T*(2) for water and fat independently. Improved quantification of fat is demonstrated, with independent estimation of T*(2) for water and fat using phantom experiments. The tradeoffs in algorithm stability and accuracy between multiexponential and single exponential techniques are discussed.
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PMID:Independent estimation of T*2 for water and fat for improved accuracy of fat quantification. 2037 85

Incidence of obesity and hepatic steatosis is increasing worldwide. Almost one quarter of western countries population suffer from non alcoholic fatty liver disease (NAFLD). The aim of this study was to investigate the frequency and predictors of nonalcoholic steatohepatitis (NASH) in patients with unexplained alanine aminotransferase activity elevation (ALT), and therefore avoid unnecessary biopsies in cases of simple steatosis. Earlier studies provided different results and have not answered the question how to distinguish NASH from simple steatosis. Ultrasound (US), computed tomography (CT) and magnetic resonance (MRI) can detect steatosis with great sensitivity level, but not NASH. This study included 50 patients (18 women and 32 men) with mean age 43 +/- 9 years, and with defined selected biochemical, anthropometric and hormone biomarkers. The average BMI was 27.1 +/- 3.81 (kg/m2), insulin resistance HOMA IR 3.89 +/-3.81. All patients underwent liver biopsy and NASH was staged by NASH activity score (NAS) from 1 to 8. Results are compared to pathohistological finding as relevant method. The results show that 90% of patients (n=45) had NAFLD (minimal stage at least), and 15 (30%) had nonalcoholic steatohepatitis (NASH). High triglyceride, low HDL and high ferritin serum levels correspond with NASH. As in earlier studies, insulin resistance as basic mechanism of NAFLD and NASH was confirmed.
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PMID:Predictors of nonalcoholic steatohepatitis in patients with elevated alanine aminotransferase activity. 2040 93

We report a case of severe subcapsular hepatic steatosis in a middle-aged woman with diabetic nephropathy requiring continuous ambulatory peritoneal dialysis (CAPD). The CT appearances of the liver were initially suspected to be due to embolic infarcts. However, an accurate diagnosis was made only after a history of intraperitoneal insulin administration was elicited, and this was confirmed on MRI with chemical shift gradient-echo pulse sequences. Haemodialysis was recommenced, and follow-up imaging 4 years later showed complete resolution of subcapsular hepatic steatosis.
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PMID:Imaging appearance of severe subcapsular hepatic steatosis: mimicking hepatic embolic infarcts. 2041 64


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